Drop privileges very early on.

[metze/wireshark/wip.git] / dumpcap.c

/* dumpcap.c
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "config.h"

#include <stdio.h>
#include <stdlib.h> /* for exit() */
#include <glib.h>

#include <string.h>
#include <ctype.h>

#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif

#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif

#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif

#ifdef HAVE_SYS_STAT_H
# include <sys/stat.h>
#endif

#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#ifdef HAVE_GETOPT_H
#include <getopt.h>
#endif

#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif

#if defined(__APPLE__) && defined(__LP64__)
#include <sys/utsname.h>
#endif

#include <signal.h>
#include <errno.h>

#ifdef HAVE_LIBZ
#include <zlib.h>       /* to get the libz version number */
#endif

#include <wsutil/cmdarg_err.h>
#include <wsutil/crash_info.h>
#include <wsutil/copyright_info.h>
#include <wsutil/ws_version_info.h>

#ifndef HAVE_GETOPT
#include "wsutil/wsgetopt.h"
#endif

#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif

#ifdef HAVE_LIBCAP
# include <sys/prctl.h>
# include <sys/capability.h>
#endif

#include "ringbuffer.h"
#include "version_info.h"

#include "capture-pcap-util.h"
#ifdef _WIN32
#include "capture-wpcap.h"
#endif /* _WIN32 */

#include "pcapio.h"

#ifdef _WIN32
#include "capture-wpcap.h"
#include <wsutil/unicode-utils.h>
#endif

#ifndef _WIN32
#include <sys/un.h>
#endif

#ifdef NEED_INET_V6DEFS_H
# include "wsutil/inet_v6defs.h"
#endif

#include <wsutil/clopts_common.h>
#include <wsutil/privileges.h>

#include "sync_pipe.h"

#include "capture_opts.h"
#include <capchild/capture_session.h>
#include <capchild/capture_ifinfo.h>
#include <capchild/capture_sync.h>

#include "conditions.h"
#include "capture_stop_conditions.h"

#include "wsutil/tempfile.h"
#include "log.h"
#include "wsutil/file_util.h"
#include "wsutil/os_version_info.h"

#include "ws80211_utils.h"

/*
 * Get information about libpcap format from "wiretap/libpcap.h".
 * XXX - can we just use pcap_open_offline() to read the pipe?
 */
#include "wiretap/libpcap.h"

/**#define DEBUG_DUMPCAP**/
/**#define DEBUG_CHILD_DUMPCAP**/

#ifdef _WIN32
#ifdef DEBUG_DUMPCAP
#include <conio.h>          /* _getch() */
#endif
#endif

#ifdef DEBUG_CHILD_DUMPCAP
FILE *debug_log;   /* for logging debug messages to  */
                   /*  a file if DEBUG_CHILD_DUMPCAP */
                   /*  is defined                    */
#endif

static GAsyncQueue *pcap_queue;
static gint64 pcap_queue_bytes;
static gint64 pcap_queue_packets;
static gint64 pcap_queue_byte_limit = 0;
static gint64 pcap_queue_packet_limit = 0;

static gboolean capture_child = FALSE; /* FALSE: standalone call, TRUE: this is an Wireshark capture child */
#ifdef _WIN32
static gchar *sig_pipe_name = NULL;
static HANDLE sig_pipe_handle = NULL;
static gboolean signal_pipe_check_running(void);
#endif

#ifdef SIGINFO
static gboolean infodelay;      /* if TRUE, don't print capture info in SIGINFO handler */
static gboolean infoprint;      /* if TRUE, print capture info after clearing infodelay */
#endif /* SIGINFO */

/** Stop a low-level capture (stops the capture child). */
static void capture_loop_stop(void);
/** Close a pipe, or socket if \a from_socket is TRUE */
static void cap_pipe_close(int pipe_fd, gboolean from_socket _U_);

#ifdef __linux__
/*
 * Enable kernel BPF JIT compiler if available.
 * If any calls fail, just drive on - the JIT compiler might not be
 * enabled, but filtering will still work, and it's not clear what
 * we could do if the calls fail; should we just report the error
 * and not continue to capture, should we report it as a warning, or
 * what?
 */
static void
enable_kernel_bpf_jit_compiler(void)
{
    int fd;
    ssize_t written _U_;
    static const char file[] = "/proc/sys/net/core/bpf_jit_enable";

    fd = open(file, O_WRONLY);
    if (fd < 0)
        return;

    written = write(fd, "1", strlen("1"));

    close(fd);
}
#endif

#if !defined (__linux__)
#ifndef HAVE_PCAP_BREAKLOOP
/*
 * We don't have pcap_breakloop(), which is the only way to ensure that
 * pcap_dispatch(), pcap_loop(), or even pcap_next() or pcap_next_ex()
 * won't, if the call to read the next packet or batch of packets is
 * is interrupted by a signal on UN*X, just go back and try again to
 * read again.
 *
 * On UN*X, we catch SIGINT as a "stop capturing" signal, and, in
 * the signal handler, set a flag to stop capturing; however, without
 * a guarantee of that sort, we can't guarantee that we'll stop capturing
 * if the read will be retried and won't time out if no packets arrive.
 *
 * Therefore, on at least some platforms, we work around the lack of
 * pcap_breakloop() by doing a select() on the pcap_t's file descriptor
 * to wait for packets to arrive, so that we're probably going to be
 * blocked in the select() when the signal arrives, and can just bail
 * out of the loop at that point.
 *
 * However, we don't want to do that on BSD (because "select()" doesn't work
 * correctly on BPF devices on at least some releases of some flavors of
 * BSD), and we don't want to do it on Windows (because "select()" is
 * something for sockets, not for arbitrary handles).  (Note that "Windows"
 * here includes Cygwin; even in its pretend-it's-UNIX environment, we're
 * using WinPcap, not a UNIX libpcap.)
 *
 * Fortunately, we don't need to do it on BSD, because the libpcap timeout
 * on BSD times out even if no packets have arrived, so we'll eventually
 * exit pcap_dispatch() with an indication that no packets have arrived,
 * and will break out of the capture loop at that point.
 *
 * On Windows, we can't send a SIGINT to stop capturing, so none of this
 * applies in any case.
 *
 * XXX - the various BSDs appear to define BSD in <sys/param.h>; we don't
 * want to include it if it's not present on this platform, however.
 */
# if !defined(__FreeBSD__) && !defined(__NetBSD__) && !defined(__OpenBSD__) && \
    !defined(__bsdi__) && !defined(__APPLE__) && !defined(_WIN32) && \
    !defined(__CYGWIN__)
#  define MUST_DO_SELECT
# endif /* avoid select */
#endif /* HAVE_PCAP_BREAKLOOP */
#else /* linux */
/* whatever the deal with pcap_breakloop, linux doesn't support timeouts
 * in pcap_dispatch(); on the other hand, select() works just fine there.
 * Hence we use a select for that come what may.
 *
 * XXX - with TPACKET_V1 and TPACKET_V2, it currently uses select()
 * internally, and, with TPACKET_V3, once that's supported, it'll
 * support timeouts, at least as I understand the way the code works.
 */
#define MUST_DO_SELECT
#endif

/** init the capture filter */
typedef enum {
    INITFILTER_NO_ERROR,
    INITFILTER_BAD_FILTER,
    INITFILTER_OTHER_ERROR
} initfilter_status_t;

typedef enum {
    STATE_EXPECT_REC_HDR,
    STATE_READ_REC_HDR,
    STATE_EXPECT_DATA,
    STATE_READ_DATA
} cap_pipe_state_t;

typedef enum {
    PIPOK,
    PIPEOF,
    PIPERR,
    PIPNEXIST
} cap_pipe_err_t;

typedef struct _pcap_options {
    guint32                      received;
    guint32                      dropped;
    guint32                      flushed;
    pcap_t                      *pcap_h;
#ifdef MUST_DO_SELECT
    int                          pcap_fd;                /**< pcap file descriptor */
#endif
    gboolean                     pcap_err;
    guint                        interface_id;
    GThread                     *tid;
    int                          snaplen;
    int                          linktype;
    gboolean                     ts_nsec;                /**< TRUE if we're using nanosecond precision. */
                                                         /**< capture pipe (unix only "input file") */
    gboolean                     from_cap_pipe;          /**< TRUE if we are capturing data from a capture pipe */
    gboolean                     from_cap_socket;        /**< TRUE if we're capturing from socket */
    struct pcap_hdr              cap_pipe_hdr;           /**< Pcap header when capturing from a pipe */
    struct pcaprec_modified_hdr  cap_pipe_rechdr;        /**< Pcap record header when capturing from a pipe */
#ifdef _WIN32
    HANDLE                       cap_pipe_h;             /**< The handle of the capture pipe */
#endif
    int                          cap_pipe_fd;            /**< the file descriptor of the capture pipe */
    gboolean                     cap_pipe_modified;      /**< TRUE if data in the pipe uses modified pcap headers */
    gboolean                     cap_pipe_byte_swapped;  /**< TRUE if data in the pipe is byte swapped */
#if defined(_WIN32)
    char *                       cap_pipe_buf;           /**< Pointer to the data buffer we read into */
    DWORD                        cap_pipe_bytes_to_read; /**< Used by cap_pipe_dispatch */
    DWORD                        cap_pipe_bytes_read;    /**< Used by cap_pipe_dispatch */
#else
    size_t                       cap_pipe_bytes_to_read; /**< Used by cap_pipe_dispatch */
    size_t                       cap_pipe_bytes_read;    /**< Used by cap_pipe_dispatch */
#endif
    cap_pipe_state_t cap_pipe_state;
    cap_pipe_err_t cap_pipe_err;

#if defined(_WIN32)
    GMutex                      *cap_pipe_read_mtx;
    GAsyncQueue                 *cap_pipe_pending_q, *cap_pipe_done_q;
#endif
} pcap_options;

typedef struct _loop_data {
    /* common */
    gboolean  go;               /**< TRUE as long as we're supposed to keep capturing */
    int       err;              /**< if non-zero, error seen while capturing */
    gint      packet_count;     /**< Number of packets we have already captured */
    gint      packet_max;       /**< Number of packets we're supposed to capture - 0 means infinite */
    guint     inpkts_to_sync_pipe; /**< Packets not already send out to the sync_pipe */
#ifdef SIGINFO
    gboolean  report_packet_count; /**< Set by SIGINFO handler; print packet count */
#endif
    GArray   *pcaps;
    /* output file(s) */
    FILE     *pdh;
    int       save_file_fd;
    guint64   bytes_written;
    guint32   autostop_files;
} loop_data;

typedef struct _pcap_queue_element {
    pcap_options       *pcap_opts;
    struct pcap_pkthdr  phdr;
    u_char             *pd;
} pcap_queue_element;

/*
 * Standard secondary message for unexpected errors.
 */
static const char please_report[] =
    "Please report this to the Wireshark developers.\n"
    "http://bugs.wireshark.org/\n"
    "(This is not a crash; please do not report it as such.)";

/*
 * This needs to be static, so that the SIGINT handler can clear the "go"
 * flag.
 */
static loop_data   global_ld;


/*
 * Timeout, in milliseconds, for reads from the stream of captured packets
 * from a capture device.
 *
 * A bug in Mac OS X 10.6 and 10.6.1 causes calls to pcap_open_live(), in
 * 64-bit applications, with sub-second timeouts not to work.  The bug is
 * fixed in 10.6.2, re-broken in 10.6.3, and again fixed in 10.6.5.
 */
#if defined(__APPLE__) && defined(__LP64__)
static gboolean need_timeout_workaround;

#define CAP_READ_TIMEOUT        (need_timeout_workaround ? 1000 : 250)
#else
#define CAP_READ_TIMEOUT        250
#endif

/*
 * Timeout, in microseconds, for reads from the stream of captured packets
 * from a pipe.  Pipes don't have the same problem that BPF devices do
 * in OS X 10.6, 10.6.1, 10.6.3, and 10.6.4, so we always use a timeout
 * of 250ms, i.e. the same value as CAP_READ_TIMEOUT when not on one
 * of the offending versions of Snow Leopard.
 *
 * On Windows this value is converted to milliseconds and passed to
 * WaitForSingleObject. If it's less than 1000 WaitForSingleObject
 * will return immediately.
 */
#if defined(_WIN32)
#define PIPE_READ_TIMEOUT   100000
#else
#define PIPE_READ_TIMEOUT   250000
#endif

#define WRITER_THREAD_TIMEOUT 100000 /* usecs */

static void
console_log_handler(const char *log_domain, GLogLevelFlags log_level,
                    const char *message, gpointer user_data _U_);

/* capture related options */
static capture_options global_capture_opts;
static gboolean quiet = FALSE;
static gboolean use_threads = FALSE;
static guint64 start_time;

static void capture_loop_write_packet_cb(u_char *pcap_opts_p, const struct pcap_pkthdr *phdr,
                                         const u_char *pd);
static void capture_loop_queue_packet_cb(u_char *pcap_opts_p, const struct pcap_pkthdr *phdr,
                                         const u_char *pd);
static void capture_loop_get_errmsg(char *errmsg, int errmsglen, const char *fname,
                                    int err, gboolean is_close);

static void WS_MSVC_NORETURN exit_main(int err) G_GNUC_NORETURN;

static void report_new_capture_file(const char *filename);
static void report_packet_count(unsigned int packet_count);
static void report_packet_drops(guint32 received, guint32 pcap_drops, guint32 drops, guint32 flushed, guint32 ps_ifdrop, gchar *name);
static void report_capture_error(const char *error_msg, const char *secondary_error_msg);
static void report_cfilter_error(capture_options *capture_opts, guint i, const char *errmsg);

#define MSG_MAX_LENGTH 4096

/* Copied from pcapio.c pcapng_write_interface_statistics_block()*/
static guint64
create_timestamp(void) {
    guint64  timestamp;
#ifdef _WIN32
    FILETIME now;
#else
    struct timeval now;
#endif

#ifdef _WIN32
    /*
     * Current time, represented as 100-nanosecond intervals since
     * January 1, 1601, 00:00:00 UTC.
     *
     * I think DWORD might be signed, so cast both parts of "now"
     * to guint32 so that the sign bit doesn't get treated specially.
     *
     * Windows 8 provides GetSystemTimePreciseAsFileTime which we
     * might want to use instead.
     */
    GetSystemTimeAsFileTime(&now);
    timestamp = (((guint64)(guint32)now.dwHighDateTime) << 32) +
                (guint32)now.dwLowDateTime;

    /*
     * Convert to same thing but as 1-microsecond, i.e. 1000-nanosecond,
     * intervals.
     */
    timestamp /= 10;

    /*
     * Subtract difference, in microseconds, between January 1, 1601
     * 00:00:00 UTC and January 1, 1970, 00:00:00 UTC.
     */
    timestamp -= G_GUINT64_CONSTANT(11644473600000000);
#else
    /*
     * Current time, represented as seconds and microseconds since
     * January 1, 1970, 00:00:00 UTC.
     */
    gettimeofday(&now, NULL);

    /*
     * Convert to delta in microseconds.
     */
    timestamp = (guint64)(now.tv_sec) * 1000000 +
                (guint64)(now.tv_usec);
#endif
    return timestamp;
}

static void
print_usage(gboolean print_ver)
{
    FILE *output;

    if (print_ver) {
        output = stdout;
        fprintf(output,
                "Dumpcap %s\n"
                "Capture network packets and dump them into a pcapng file.\n"
                "See http://www.wireshark.org for more information.\n",
                get_ws_vcs_version_info());
    } else {
        output = stderr;
    }
    fprintf(output, "\nUsage: dumpcap [options] ...\n");
    fprintf(output, "\n");
    fprintf(output, "Capture interface:\n");
    fprintf(output, "  -i <interface>           name or idx of interface (def: first non-loopback),\n"
                    "                           or for remote capturing, use one of these formats:\n"
                    "                               rpcap://<host>/<interface>\n"
                    "                               TCP@<host>:<port>\n");
    fprintf(output, "  -f <capture filter>      packet filter in libpcap filter syntax\n");
    fprintf(output, "  -s <snaplen>             packet snapshot length (def: 65535)\n");
    fprintf(output, "  -p                       don't capture in promiscuous mode\n");
#ifdef HAVE_PCAP_CREATE
    fprintf(output, "  -I                       capture in monitor mode, if available\n");
#endif
#if defined(_WIN32) || defined(HAVE_PCAP_CREATE)
    fprintf(output, "  -B <buffer size>         size of kernel buffer in MiB (def: %dMiB)\n", DEFAULT_CAPTURE_BUFFER_SIZE);
#endif
    fprintf(output, "  -y <link type>           link layer type (def: first appropriate)\n");
    fprintf(output, "  -D                       print list of interfaces and exit\n");
    fprintf(output, "  -L                       print list of link-layer types of iface and exit\n");
#ifdef HAVE_BPF_IMAGE
    fprintf(output, "  -d                       print generated BPF code for capture filter\n");
#endif
    fprintf(output, "  -k                       set channel on wifi interface <freq>,[<type>]\n");
    fprintf(output, "  -S                       print statistics for each interface once per second\n");
    fprintf(output, "  -M                       for -D, -L, and -S, produce machine-readable output\n");
    fprintf(output, "\n");
#ifdef HAVE_PCAP_REMOTE
    fprintf(output, "RPCAP options:\n");
    fprintf(output, "  -r                       don't ignore own RPCAP traffic in capture\n");
    fprintf(output, "  -u                       use UDP for RPCAP data transfer\n");
    fprintf(output, "  -A <user>:<password>     use RPCAP password authentication\n");
#ifdef HAVE_PCAP_SETSAMPLING
    fprintf(output, "  -m <sampling type>       use packet sampling\n");
    fprintf(output, "                           count:NUM - capture one packet of every NUM\n");
    fprintf(output, "                           timer:NUM - capture no more than 1 packet in NUM ms\n");
#endif
#endif
    fprintf(output, "Stop conditions:\n");
    fprintf(output, "  -c <packet count>        stop after n packets (def: infinite)\n");
    fprintf(output, "  -a <autostop cond.> ...  duration:NUM - stop after NUM seconds\n");
    fprintf(output, "                           filesize:NUM - stop this file after NUM KB\n");
    fprintf(output, "                              files:NUM - stop after NUM files\n");
    /*fprintf(output, "\n");*/
    fprintf(output, "Output (files):\n");
    fprintf(output, "  -w <filename>            name of file to save (def: tempfile)\n");
    fprintf(output, "  -g                       enable group read access on the output file(s)\n");
    fprintf(output, "  -b <ringbuffer opt.> ... duration:NUM - switch to next file after NUM secs\n");
    fprintf(output, "                           filesize:NUM - switch to next file after NUM KB\n");
    fprintf(output, "                              files:NUM - ringbuffer: replace after NUM files\n");
    fprintf(output, "  -n                       use pcapng format instead of pcap (default)\n");
    fprintf(output, "  -P                       use libpcap format instead of pcapng\n");
    fprintf(output, "  --capture-comment <comment>\n");
    fprintf(output, "                           add a capture comment to the output file\n");
    fprintf(output, "                           (only for pcapng)\n");
    fprintf(output, "\n");
    fprintf(output, "Miscellaneous:\n");
    fprintf(output, "  -N <packet_limit>        maximum number of packets buffered within dumpcap\n");
    fprintf(output, "  -C <byte_limit>          maximum number of bytes used for buffering packets\n");
    fprintf(output, "                           within dumpcap\n");
    fprintf(output, "  -t                       use a separate thread per interface\n");
    fprintf(output, "  -q                       don't report packet capture counts\n");
    fprintf(output, "  -v                       print version information and exit\n");
    fprintf(output, "  -h                       display this help and exit\n");
    fprintf(output, "\n");
#ifdef __linux__
    fprintf(output, "WARNING: dumpcap will enable kernel BPF JIT compiler if available.\n");
    fprintf(output, "You might want to reset it\n");
    fprintf(output, "By doing \"echo 0 > /proc/sys/net/core/bpf_jit_enable\"\n");
    fprintf(output, "\n");
#endif
    fprintf(output, "Example: dumpcap -i eth0 -a duration:60 -w output.pcapng\n");
    fprintf(output, "\"Capture packets from interface eth0 until 60s passed into output.pcapng\"\n");
    fprintf(output, "\n");
    fprintf(output, "Use Ctrl-C to stop capturing at any time.\n");
}

static void
show_version(GString *comp_info_str, GString *runtime_info_str)
{
    printf(
        "Dumpcap %s\n"
        "\n"
        "%s\n"
        "%s\n"
        "%s\n"
        "See http://www.wireshark.org for more information.\n",
        get_ws_vcs_version_info(), get_copyright_info(), comp_info_str->str, runtime_info_str->str);
}

/*
 * Report an error in command-line arguments.
 * If we're a capture child, send a message back to the parent, otherwise
 * just print it.
 */
static void
dumpcap_cmdarg_err(const char *fmt, va_list ap)
{
    if (capture_child) {
        gchar *msg;
        /* Generate a 'special format' message back to parent */
        msg = g_strdup_vprintf(fmt, ap);
        sync_pipe_errmsg_to_parent(2, msg, "");
        g_free(msg);
    } else {
        fprintf(stderr, "dumpcap: ");
        vfprintf(stderr, fmt, ap);
        fprintf(stderr, "\n");
    }
}

/*
 * Report additional information for an error in command-line arguments.
 * If we're a capture child, send a message back to the parent, otherwise
 * just print it.
 */
static void
dumpcap_cmdarg_err_cont(const char *fmt, va_list ap)
{
    if (capture_child) {
        gchar *msg;
        msg = g_strdup_vprintf(fmt, ap);
        sync_pipe_errmsg_to_parent(2, msg, "");
        g_free(msg);
    } else {
        vfprintf(stderr, fmt, ap);
        fprintf(stderr, "\n");
    }
}

#ifdef HAVE_LIBCAP
static void
#if 0 /* Set to enable capability debugging */
/* see 'man cap_to_text()' for explanation of output                         */
/* '='   means 'all= '  ie: no capabilities                                  */
/* '=ip' means 'all=ip' ie: all capabilities are permissible and inheritable */
/* ....                                                                      */
print_caps(const char *pfx) {
    cap_t caps = cap_get_proc();
    g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG,
          "%s: EUID: %d  Capabilities: %s", pfx,
          geteuid(), cap_to_text(caps, NULL));
    cap_free(caps);
#else
print_caps(const char *pfx _U_) {
#endif
}

static void
relinquish_all_capabilities(void)
{
    /* Drop any and all capabilities this process may have.            */
    /* Allowed whether or not process has any privileges.              */
    cap_t caps = cap_init();    /* all capabilities initialized to off */
    print_caps("Pre-clear");
    if (cap_set_proc(caps)) {
        cmdarg_err("cap_set_proc() fail return: %s", g_strerror(errno));
    }
    print_caps("Post-clear");
    cap_free(caps);
}
#endif

static pcap_t *
open_capture_device(interface_options *interface_opts,
                    char (*open_err_str)[PCAP_ERRBUF_SIZE])
{
    pcap_t *pcap_h;
#ifdef HAVE_PCAP_CREATE
    int         err;
#endif
#if defined(HAVE_PCAP_OPEN) && defined(HAVE_PCAP_REMOTE)
    struct pcap_rmtauth auth;
#endif

    /* Open the network interface to capture from it.
       Some versions of libpcap may put warnings into the error buffer
       if they succeed; to tell if that's happened, we have to clear
       the error buffer, and check if it's still a null string.  */
    g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "Entering open_capture_device().");
    (*open_err_str)[0] = '\0';
#if defined(HAVE_PCAP_OPEN) && defined(HAVE_PCAP_REMOTE)
    /*
     * If we're opening a remote device, use pcap_open(); that's currently
     * the only open routine that supports remote devices.
     */
    if (strncmp (interface_opts->name, "rpcap://", 8) == 0) {
        auth.type = interface_opts->auth_type == CAPTURE_AUTH_PWD ?
            RPCAP_RMTAUTH_PWD : RPCAP_RMTAUTH_NULL;
        auth.username = interface_opts->auth_username;
        auth.password = interface_opts->auth_password;

        g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG,
              "Calling pcap_open() using name %s, snaplen %d, promisc_mode %d, datatx_udp %d, nocap_rpcap %d.",
              interface_opts->name, interface_opts->snaplen, interface_opts->promisc_mode,
              interface_opts->datatx_udp, interface_opts->nocap_rpcap);
        pcap_h = pcap_open(interface_opts->name, interface_opts->snaplen,
                           /* flags */
                           (interface_opts->promisc_mode ? PCAP_OPENFLAG_PROMISCUOUS : 0) |
                           (interface_opts->datatx_udp ? PCAP_OPENFLAG_DATATX_UDP : 0) |
                           (interface_opts->nocap_rpcap ? PCAP_OPENFLAG_NOCAPTURE_RPCAP : 0),
                           CAP_READ_TIMEOUT, &auth, *open_err_str);
        if (pcap_h == NULL) {
            /* Error - did pcap actually supply an error message? */
            if ((*open_err_str)[0] == '\0') {
                /* Work around known WinPcap bug wherein no error message is
                   filled in on a failure to open an rpcap: URL. */
                g_strlcpy(*open_err_str,
                          "Unknown error (pcap bug; actual error cause not reported)",
                          sizeof *open_err_str);
            }
        }
        g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG,
              "pcap_open() returned %p.", (void *)pcap_h);
    } else
#endif
    {
        /*
         * If we're not opening a remote device, use pcap_create() and
         * pcap_activate() if we have them, so that we can set the buffer
         * size, otherwise use pcap_open_live().
         */
#ifdef HAVE_PCAP_CREATE
        g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG,
              "Calling pcap_create() using %s.", interface_opts->name);
        pcap_h = pcap_create(interface_opts->name, *open_err_str);
        g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG,
              "pcap_create() returned %p.", (void *)pcap_h);
        if (pcap_h != NULL) {
            g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG,
                  "Calling pcap_set_snaplen() with snaplen %d.", interface_opts->snaplen);
            pcap_set_snaplen(pcap_h, interface_opts->snaplen);
            g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG,
                  "Calling pcap_set_promisc() with promisc_mode %d.", interface_opts->promisc_mode);
            pcap_set_promisc(pcap_h, interface_opts->promisc_mode);
            pcap_set_timeout(pcap_h, CAP_READ_TIMEOUT);

            g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG,
                  "buffersize %d.", interface_opts->buffer_size);
            if (interface_opts->buffer_size != 0) {
                pcap_set_buffer_size(pcap_h, interface_opts->buffer_size * 1024 * 1024);
            }
            g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG,
                  "monitor_mode %d.", interface_opts->monitor_mode);
            if (interface_opts->monitor_mode)
                pcap_set_rfmon(pcap_h, 1);
            err = pcap_activate(pcap_h);
            g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG,
                  "pcap_activate() returned %d.", err);
            if (err < 0) {
                /* Failed to activate, set to NULL */
                if (err == PCAP_ERROR)
                    g_strlcpy(*open_err_str, pcap_geterr(pcap_h), sizeof *open_err_str);
                else
                    g_strlcpy(*open_err_str, pcap_statustostr(err), sizeof *open_err_str);
                pcap_close(pcap_h);
                pcap_h = NULL;
            }
        }
#else
        g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG,
              "pcap_open_live() calling using name %s, snaplen %d, promisc_mode %d.",
              interface_opts->name, interface_opts->snaplen, interface_opts->promisc_mode);
        pcap_h = pcap_open_live(interface_opts->name, interface_opts->snaplen,
                                interface_opts->promisc_mode, CAP_READ_TIMEOUT,
                                *open_err_str);
        g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG,
              "pcap_open_live() returned %p.", (void *)pcap_h);
#endif
    }
    g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "open_capture_device %s : %s", pcap_h ? "SUCCESS" : "FAILURE", interface_opts->name);
    return pcap_h;
}

static void
get_capture_device_open_failure_messages(const char *open_err_str,
                                         const char *iface,
                                         char *errmsg, size_t errmsg_len,
                                         char *secondary_errmsg,
                                         size_t secondary_errmsg_len)
{
#ifndef _WIN32
    const char *libpcap_warn;
    static const char ppamsg[] = "can't find PPA for ";
#endif

    g_snprintf(errmsg, (gulong) errmsg_len,
               "The capture session could not be initiated on interface '%s' (%s).",
               iface, open_err_str);
#ifdef _WIN32
    if (!has_wpcap) {
      g_snprintf(secondary_errmsg, (gulong) secondary_errmsg_len,
                 "\n"
                 "In order to capture packets, WinPcap must be installed; see\n"
                 "\n"
                 "        http://www.winpcap.org/\n"
                 "\n"
                 "or the mirror at\n"
                 "\n"
                 "        http://www.mirrors.wiretapped.net/security/packet-capture/winpcap/\n"
                 "\n"
                 "or the mirror at\n"
                 "\n"
                 "        http://winpcap.cs.pu.edu.tw/\n"
                 "\n"
                 "for a downloadable version of WinPcap and for instructions on how to install\n"
                 "WinPcap.");
    } else {
      g_snprintf(secondary_errmsg, (gulong) secondary_errmsg_len,
                 "\n"
                 "Please check that \"%s\" is the proper interface.\n"
                 "\n"
                 "\n"
                 "Help can be found at:\n"
                 "\n"
                 "       http://wiki.wireshark.org/WinPcap\n"
                 "       http://wiki.wireshark.org/CaptureSetup\n",
                 iface);
    }
#else
    /* If we got a "can't find PPA for X" message, warn the user (who
       is running dumpcap on HP-UX) that they don't have a version of
       libpcap that properly handles HP-UX (libpcap 0.6.x and later
       versions, which properly handle HP-UX, say "can't find /dev/dlpi
       PPA for X" rather than "can't find PPA for X"). */
    if (strncmp(open_err_str, ppamsg, sizeof ppamsg - 1) == 0)
        libpcap_warn =
            "\n\n"
            "You are running (T)Wireshark with a version of the libpcap library\n"
            "that doesn't handle HP-UX network devices well; this means that\n"
            "(T)Wireshark may not be able to capture packets.\n"
            "\n"
            "To fix this, you should install libpcap 0.6.2, or a later version\n"
            "of libpcap, rather than libpcap 0.4 or 0.5.x.  It is available in\n"
            "packaged binary form from the Software Porting And Archive Centre\n"
            "for HP-UX; the Centre is at http://hpux.connect.org.uk/ - the page\n"
            "at the URL lists a number of mirror sites.";
    else
        libpcap_warn = "";

    g_snprintf(secondary_errmsg, (gulong) secondary_errmsg_len,
               "Please check to make sure you have sufficient permissions, and that you have "
               "the proper interface or pipe specified.%s", libpcap_warn);
#endif /* _WIN32 */
}

/* Set the data link type on a pcap. */
static gboolean
set_pcap_linktype(pcap_t *pcap_h, int linktype, char *name,
                  char *errmsg, size_t errmsg_len,
                  char *secondary_errmsg, size_t secondary_errmsg_len)
{
    char *set_linktype_err_str;

    if (linktype == -1)
        return TRUE; /* just use the default */
#ifdef HAVE_PCAP_SET_DATALINK
    if (pcap_set_datalink(pcap_h, linktype) == 0)
        return TRUE; /* no error */
    set_linktype_err_str = pcap_geterr(pcap_h);
#else
    /* Let them set it to the type it is; reject any other request. */
    if (get_pcap_linktype(pcap_h, name) == linktype)
        return TRUE; /* no error */
    set_linktype_err_str =
        "That DLT isn't one of the DLTs supported by this device";
#endif
    g_snprintf(errmsg, (gulong) errmsg_len, "Unable to set data link type on interface '%s' (%s).",
               name, set_linktype_err_str);
    /*
     * If the error isn't "XXX is not one of the DLTs supported by this device",
     * tell the user to tell the Wireshark developers about it.
     */
    if (strstr(set_linktype_err_str, "is not one of the DLTs supported by this device") == NULL)
        g_snprintf(secondary_errmsg, (gulong) secondary_errmsg_len, please_report);
    else
        secondary_errmsg[0] = '\0';
    return FALSE;
}

static gboolean
compile_capture_filter(const char *iface, pcap_t *pcap_h,
                       struct bpf_program *fcode, const char *cfilter)
{
    bpf_u_int32 netnum, netmask;
    gchar       lookup_net_err_str[PCAP_ERRBUF_SIZE];

    if (pcap_lookupnet(iface, &netnum, &netmask, lookup_net_err_str) < 0) {
        /*
         * Well, we can't get the netmask for this interface; it's used
         * only for filters that check for broadcast IP addresses, so
         * we just punt and use 0.  It might be nice to warn the user,
         * but that's a pain in a GUI application, as it'd involve popping
         * up a message box, and it's not clear how often this would make
         * a difference (only filters that check for IP broadcast addresses
         * use the netmask).
         */
        /*cmdarg_err(
          "Warning:  Couldn't obtain netmask info (%s).", lookup_net_err_str);*/
        netmask = 0;
    }

    /*
     * Sigh.  Older versions of libpcap don't properly declare the
     * third argument to pcap_compile() as a const pointer.  Cast
     * away the warning.
     */
    if (pcap_compile(pcap_h, fcode, (char *)cfilter, 1, netmask) < 0)
        return FALSE;
    return TRUE;
}

#ifdef HAVE_BPF_IMAGE
static gboolean
show_filter_code(capture_options *capture_opts)
{
    interface_options interface_opts;
    pcap_t *pcap_h;
    gchar open_err_str[PCAP_ERRBUF_SIZE];
    char errmsg[MSG_MAX_LENGTH+1];
    char secondary_errmsg[MSG_MAX_LENGTH+1];
    struct bpf_program fcode;
    struct bpf_insn *insn;
    u_int i;
    guint j;

    for (j = 0; j < capture_opts->ifaces->len; j++) {
        interface_opts = g_array_index(capture_opts->ifaces, interface_options, j);
        pcap_h = open_capture_device(&interface_opts, &open_err_str);
        if (pcap_h == NULL) {
            /* Open failed; get messages */
            get_capture_device_open_failure_messages(open_err_str,
                                                     interface_opts.name,
                                                     errmsg, sizeof errmsg,
                                                     secondary_errmsg,
                                                     sizeof secondary_errmsg);
            /* And report them */
            report_capture_error(errmsg, secondary_errmsg);
            return FALSE;
        }

        /* Set the link-layer type. */
        if (!set_pcap_linktype(pcap_h, interface_opts.linktype, interface_opts.name,
                               errmsg, sizeof errmsg,
                               secondary_errmsg, sizeof secondary_errmsg)) {
            pcap_close(pcap_h);
            report_capture_error(errmsg, secondary_errmsg);
            return FALSE;
        }

        /* OK, try to compile the capture filter. */
        if (!compile_capture_filter(interface_opts.name, pcap_h, &fcode,
                                    interface_opts.cfilter)) {
            pcap_close(pcap_h);
            report_cfilter_error(capture_opts, j, errmsg);
            return FALSE;
        }
        pcap_close(pcap_h);

        /* Now print the filter code. */
        insn = fcode.bf_insns;

        for (i = 0; i < fcode.bf_len; insn++, i++)
            printf("%s\n", bpf_image(insn, i));
    }
    /* If not using libcap: we now can now set euid/egid to ruid/rgid         */
    /*  to remove any suid privileges.                                        */
    /* If using libcap: we can now remove NET_RAW and NET_ADMIN capabilities  */
    /*  (euid/egid have already previously been set to ruid/rgid.             */
    /* (See comment in main() for details)                                    */
#ifndef HAVE_LIBCAP
    relinquish_special_privs_perm();
#else
    relinquish_all_capabilities();
#endif
    if (capture_child) {
        /* Let our parent know we succeeded. */
        pipe_write_block(2, SP_SUCCESS, NULL);
    }
    return TRUE;
}
#endif

/*
 * capture_interface_list() is expected to do the right thing to get
 * a list of interfaces.
 *
 * In most of the programs in the Wireshark suite, "the right thing"
 * is to run dumpcap and ask it for the list, because dumpcap may
 * be the only program in the suite with enough privileges to get
 * the list.
 *
 * In dumpcap itself, however, we obviously can't run dumpcap to
 * ask for the list.  Therefore, our capture_interface_list() should
 * just call get_interface_list().
 */
GList *
capture_interface_list(int *err, char **err_str, void(*update_cb)(void) _U_)
{
    return get_interface_list(err, err_str);
}

/*
 * Get the data-link type for a libpcap device.
 * This works around AIX 5.x's non-standard and incompatible-with-the-
 * rest-of-the-universe libpcap.
 */
static int
get_pcap_linktype(pcap_t *pch, const char *devicename
#ifndef _AIX
        _U_
#endif
)
{
    int linktype;
#ifdef _AIX
    const char *ifacename;
#endif

    linktype = pcap_datalink(pch);
#ifdef _AIX

    /*
     * The libpcap that comes with AIX 5.x uses RFC 1573 ifType values
     * rather than DLT_ values for link-layer types; the ifType values
     * for LAN devices are:
     *
     *  Ethernet        6
     *  802.3           7
     *  Token Ring      9
     *  FDDI            15
     *
     * and the ifType value for a loopback device is 24.
     *
     * The AIX names for LAN devices begin with:
     *
     *  Ethernet                en
     *  802.3                   et
     *  Token Ring              tr
     *  FDDI                    fi
     *
     * and the AIX names for loopback devices begin with "lo".
     *
     * (The difference between "Ethernet" and "802.3" is presumably
     * whether packets have an Ethernet header, with a packet type,
     * or an 802.3 header, with a packet length, followed by an 802.2
     * header and possibly a SNAP header.)
     *
     * If the device name matches "linktype" interpreted as an ifType
     * value, rather than as a DLT_ value, we will assume this is AIX's
     * non-standard, incompatible libpcap, rather than a standard libpcap,
     * and will map the link-layer type to the standard DLT_ value for
     * that link-layer type, as that's what the rest of Wireshark expects.
     *
     * (This means the capture files won't be readable by a tcpdump
     * linked with AIX's non-standard libpcap, but so it goes.  They
     * *will* be readable by standard versions of tcpdump, Wireshark,
     * and so on.)
     *
     * XXX - if we conclude we're using AIX libpcap, should we also
     * set a flag to cause us to assume the time stamps are in
     * seconds-and-nanoseconds form, and to convert them to
     * seconds-and-microseconds form before processing them and
     * writing them out?
     */

    /*
     * Find the last component of the device name, which is the
     * interface name.
     */
    ifacename = strchr(devicename, '/');
    if (ifacename == NULL)
        ifacename = devicename;

    /* See if it matches any of the LAN device names. */
    if (strncmp(ifacename, "en", 2) == 0) {
        if (linktype == 6) {
            /*
             * That's the RFC 1573 value for Ethernet; map it to DLT_EN10MB.
             */
            linktype = 1;
        }
    } else if (strncmp(ifacename, "et", 2) == 0) {
        if (linktype == 7) {
            /*
             * That's the RFC 1573 value for 802.3; map it to DLT_EN10MB.
             * (libpcap, tcpdump, Wireshark, etc. don't care if it's Ethernet
             * or 802.3.)
             */
            linktype = 1;
        }
    } else if (strncmp(ifacename, "tr", 2) == 0) {
        if (linktype == 9) {
            /*
             * That's the RFC 1573 value for 802.5 (Token Ring); map it to
             * DLT_IEEE802, which is what's used for Token Ring.
             */
            linktype = 6;
        }
    } else if (strncmp(ifacename, "fi", 2) == 0) {
        if (linktype == 15) {
            /*
             * That's the RFC 1573 value for FDDI; map it to DLT_FDDI.
             */
            linktype = 10;
        }
    } else if (strncmp(ifacename, "lo", 2) == 0) {
        if (linktype == 24) {
            /*
             * That's the RFC 1573 value for "software loopback" devices; map it
             * to DLT_NULL, which is what's used for loopback devices on BSD.
             */
            linktype = 0;
        }
    }
#endif

    return linktype;
}

static data_link_info_t *
create_data_link_info(int dlt)
{
    data_link_info_t *data_link_info;
    const char *text;

    data_link_info = (data_link_info_t *)g_malloc(sizeof (data_link_info_t));
    data_link_info->dlt = dlt;
    text = pcap_datalink_val_to_name(dlt);
    if (text != NULL)
        data_link_info->name = g_strdup(text);
    else
        data_link_info->name = g_strdup_printf("DLT %d", dlt);
    text = pcap_datalink_val_to_description(dlt);
    if (text != NULL)
        data_link_info->description = g_strdup(text);
    else
        data_link_info->description = NULL;
    return data_link_info;
}

/*
 * Get the capabilities of a network device.
 */
static if_capabilities_t *
get_if_capabilities(const char *devicename, gboolean monitor_mode
#ifndef HAVE_PCAP_CREATE
        _U_
#endif
, char **err_str)
{
    if_capabilities_t *caps;
    char errbuf[PCAP_ERRBUF_SIZE];
    pcap_t *pch;
#ifdef HAVE_PCAP_CREATE
    int status;
#endif
    int deflt;
#ifdef HAVE_PCAP_LIST_DATALINKS
    int *linktypes;
    int i, nlt;
#endif
    data_link_info_t *data_link_info;

    /*
     * Allocate the interface capabilities structure.
     */
    caps = (if_capabilities_t *)g_malloc(sizeof *caps);

    /*
     * WinPcap 4.1.2, and possibly earlier versions, have a bug
     * wherein, when an open with an rpcap: URL fails, the error
     * message for the error is not copied to errbuf and whatever
     * on-the-stack junk is in errbuf is treated as the error
     * message.
     *
     * To work around that (and any other bugs of that sort, we
     * initialize errbuf to an empty string.  If we get an error
     * and the string is empty, we report it as an unknown error.
     * (If we *don't* get an error, and the string is *non*-empty,
     * that could be a warning returned, such as "can't turn
     * promiscuous mode on"; we currently don't do so.)
     */
    errbuf[0] = '\0';
#ifdef HAVE_PCAP_OPEN
    pch = pcap_open(devicename, MIN_PACKET_SIZE, 0, 0, NULL, errbuf);
    caps->can_set_rfmon = FALSE;
    if (pch == NULL) {
        if (err_str != NULL)
            *err_str = g_strdup(errbuf[0] == '\0' ? "Unknown error (pcap bug; actual error cause not reported)" : errbuf);
        g_free(caps);
        return NULL;
    }
#elif defined(HAVE_PCAP_CREATE)
    pch = pcap_create(devicename, errbuf);
    if (pch == NULL) {
        if (err_str != NULL)
            *err_str = g_strdup(errbuf);
        g_free(caps);
        return NULL;
    }
    status = pcap_can_set_rfmon(pch);
    if (status < 0) {
        /* Error. */
        if (status == PCAP_ERROR)
            *err_str = g_strdup_printf("pcap_can_set_rfmon() failed: %s",
                                       pcap_geterr(pch));
        else
            *err_str = g_strdup(pcap_statustostr(status));
        pcap_close(pch);
        g_free(caps);
        return NULL;
    }
    if (status == 0)
        caps->can_set_rfmon = FALSE;
    else if (status == 1) {
        caps->can_set_rfmon = TRUE;
        if (monitor_mode)
            pcap_set_rfmon(pch, 1);
    } else {
        if (err_str != NULL) {
            *err_str = g_strdup_printf("pcap_can_set_rfmon() returned %d",
                                       status);
        }
        pcap_close(pch);
        g_free(caps);
        return NULL;
    }

    status = pcap_activate(pch);
    if (status < 0) {
        /* Error.  We ignore warnings (status > 0). */
        if (err_str != NULL) {
            if (status == PCAP_ERROR)
                *err_str = g_strdup_printf("pcap_activate() failed: %s",
                                           pcap_geterr(pch));
            else
                *err_str = g_strdup(pcap_statustostr(status));
        }
        pcap_close(pch);
        g_free(caps);
        return NULL;
    }
#else
    pch = pcap_open_live(devicename, MIN_PACKET_SIZE, 0, 0, errbuf);
    caps->can_set_rfmon = FALSE;
    if (pch == NULL) {
        if (err_str != NULL)
            *err_str = g_strdup(errbuf[0] == '\0' ? "Unknown error (pcap bug; actual error cause not reported)" : errbuf);
        g_free(caps);
        return NULL;
    }
#endif
    deflt = get_pcap_linktype(pch, devicename);
#ifdef HAVE_PCAP_LIST_DATALINKS
    nlt = pcap_list_datalinks(pch, &linktypes);
    if (nlt == 0 || linktypes == NULL) {
        pcap_close(pch);
        if (err_str != NULL)
            *err_str = NULL; /* an empty list doesn't mean an error */
        g_free(caps);
        return NULL;
    }
    caps->data_link_types = NULL;
    for (i = 0; i < nlt; i++) {
        data_link_info = create_data_link_info(linktypes[i]);

        /*
         * XXX - for 802.11, make the most detailed 802.11
         * version the default, rather than the one the
         * device has as the default?
         */
        if (linktypes[i] == deflt)
            caps->data_link_types = g_list_prepend(caps->data_link_types,
                                                   data_link_info);
        else
            caps->data_link_types = g_list_append(caps->data_link_types,
                                                  data_link_info);
    }
#ifdef HAVE_PCAP_FREE_DATALINKS
    pcap_free_datalinks(linktypes);
#else
    /*
     * In Windows, there's no guarantee that if you have a library
     * built with one version of the MSVC++ run-time library, and
     * it returns a pointer to allocated data, you can free that
     * data from a program linked with another version of the
     * MSVC++ run-time library.
     *
     * This is not an issue on UN*X.
     *
     * See the mail threads starting at
     *
     *    http://www.winpcap.org/pipermail/winpcap-users/2006-September/001421.html
     *
     * and
     *
     *    http://www.winpcap.org/pipermail/winpcap-users/2008-May/002498.html
     */
#ifndef _WIN32
#define xx_free free  /* hack so checkAPIs doesn't complain */
    xx_free(linktypes);
#endif /* _WIN32 */
#endif /* HAVE_PCAP_FREE_DATALINKS */
#else /* HAVE_PCAP_LIST_DATALINKS */

    data_link_info = create_data_link_info(deflt);
    caps->data_link_types = g_list_append(caps->data_link_types,
                                          data_link_info);
#endif /* HAVE_PCAP_LIST_DATALINKS */

    pcap_close(pch);

    if (err_str != NULL)
        *err_str = NULL;
    return caps;
}

#define ADDRSTRLEN 46 /* Covers IPv4 & IPv6 */
/*
 * Output a machine readable list of the interfaces
 * This list is retrieved by the sync_interface_list_open() function
 * The actual output of this function can be viewed with the command "dumpcap -D -Z none"
 */
static void
print_machine_readable_interfaces(GList *if_list)
{
    int         i;
    GList       *if_entry;
    if_info_t   *if_info;
    GSList      *addr;
    if_addr_t   *if_addr;
    char        addr_str[ADDRSTRLEN];

    if (capture_child) {
        /* Let our parent know we succeeded. */
        pipe_write_block(2, SP_SUCCESS, NULL);
    }

    i = 1;  /* Interface id number */
    for (if_entry = g_list_first(if_list); if_entry != NULL;
         if_entry = g_list_next(if_entry)) {
        if_info = (if_info_t *)if_entry->data;
        printf("%d. %s\t", i++, if_info->name);

        /*
         * Print the contents of the if_entry struct in a parseable format.
         * Each if_entry element is tab-separated.  Addresses are comma-
         * separated.
         */
        /* XXX - Make sure our description doesn't contain a tab */
        if (if_info->vendor_description != NULL)
            printf("%s\t", if_info->vendor_description);
        else
            printf("\t");

        /* XXX - Make sure our friendly name doesn't contain a tab */
        if (if_info->friendly_name != NULL)
            printf("%s\t", if_info->friendly_name);
        else
            printf("\t");

        printf("%i\t", if_info->type);

        for (addr = g_slist_nth(if_info->addrs, 0); addr != NULL;
                    addr = g_slist_next(addr)) {
            if (addr != g_slist_nth(if_info->addrs, 0))
                printf(",");

            if_addr = (if_addr_t *)addr->data;
            switch(if_addr->ifat_type) {
            case IF_AT_IPv4:
                if (inet_ntop(AF_INET, &if_addr->addr.ip4_addr, addr_str,
                              ADDRSTRLEN)) {
                    printf("%s", addr_str);
                } else {
                    printf("<unknown IPv4>");
                }
                break;
            case IF_AT_IPv6:
                if (inet_ntop(AF_INET6, &if_addr->addr.ip6_addr,
                              addr_str, ADDRSTRLEN)) {
                    printf("%s", addr_str);
                } else {
                    printf("<unknown IPv6>");
                }
                break;
            default:
                printf("<type unknown %i>", if_addr->ifat_type);
            }
        }

        if (if_info->loopback)
            printf("\tloopback");
        else
            printf("\tnetwork");

        printf("\n");
    }
}

/*
 * If you change the machine-readable output format of this function,
 * you MUST update capture_ifinfo.c:capture_get_if_capabilities() accordingly!
 */
static void
print_machine_readable_if_capabilities(if_capabilities_t *caps)
{
    GList *lt_entry;
    data_link_info_t *data_link_info;
    const gchar *desc_str;

    if (capture_child) {
        /* Let our parent know we succeeded. */
        pipe_write_block(2, SP_SUCCESS, NULL);
    }

    if (caps->can_set_rfmon)
        printf("1\n");
    else
        printf("0\n");
    for (lt_entry = caps->data_link_types; lt_entry != NULL;
         lt_entry = g_list_next(lt_entry)) {
      data_link_info = (data_link_info_t *)lt_entry->data;
      if (data_link_info->description != NULL)
        desc_str = data_link_info->description;
      else
        desc_str = "(not supported)";
      printf("%d\t%s\t%s\n", data_link_info->dlt, data_link_info->name,
             desc_str);
    }
}

typedef struct {
    char *name;
    pcap_t *pch;
} if_stat_t;

/* Print the number of packets captured for each interface until we're killed. */
static int
print_statistics_loop(gboolean machine_readable)
{
    GList       *if_list, *if_entry, *stat_list = NULL, *stat_entry;
    if_info_t   *if_info;
    if_stat_t   *if_stat;
    int         err;
    gchar       *err_str;
    pcap_t      *pch;
    char        errbuf[PCAP_ERRBUF_SIZE];
    struct pcap_stat ps;

    if_list = get_interface_list(&err, &err_str);
    if (if_list == NULL) {
        switch (err) {
        case CANT_GET_INTERFACE_LIST:
        case DONT_HAVE_PCAP:
            cmdarg_err("%s", err_str);
            g_free(err_str);
            break;

        case NO_INTERFACES_FOUND:
            cmdarg_err("There are no interfaces on which a capture can be done");
            break;
        }
        return err;
    }

    for (if_entry = g_list_first(if_list); if_entry != NULL; if_entry = g_list_next(if_entry)) {
        if_info = (if_info_t *)if_entry->data;
#ifdef HAVE_PCAP_OPEN
        pch = pcap_open(if_info->name, MIN_PACKET_SIZE, 0, 0, NULL, errbuf);
#else
        pch = pcap_open_live(if_info->name, MIN_PACKET_SIZE, 0, 0, errbuf);
#endif

        if (pch) {
            if_stat = (if_stat_t *)g_malloc(sizeof(if_stat_t));
            if_stat->name = g_strdup(if_info->name);
            if_stat->pch = pch;
            stat_list = g_list_append(stat_list, if_stat);
        }
    }

    if (!stat_list) {
        cmdarg_err("There are no interfaces on which a capture can be done");
        return 2;
    }

    if (capture_child) {
        /* Let our parent know we succeeded. */
        pipe_write_block(2, SP_SUCCESS, NULL);
    }

    if (!machine_readable) {
        printf("%-15s  %10s  %10s\n", "Interface", "Received",
            "Dropped");
    }

    global_ld.go = TRUE;
    while (global_ld.go) {
        for (stat_entry = g_list_first(stat_list); stat_entry != NULL; stat_entry = g_list_next(stat_entry)) {
            if_stat = (if_stat_t *)stat_entry->data;
            pcap_stats(if_stat->pch, &ps);

            if (!machine_readable) {
                printf("%-15s  %10u  %10u\n", if_stat->name,
                    ps.ps_recv, ps.ps_drop);
            } else {
                printf("%s\t%u\t%u\n", if_stat->name,
                    ps.ps_recv, ps.ps_drop);
                fflush(stdout);
            }
        }
#ifdef _WIN32
        /* If we have a dummy signal pipe check it */
        if (!signal_pipe_check_running()) {
            global_ld.go = FALSE;
        }
        Sleep(1 * 1000);
#else
        sleep(1);
#endif
    }

    /* XXX - Not reached.  Should we look for 'q' in stdin? */
    for (stat_entry = g_list_first(stat_list); stat_entry != NULL; stat_entry = g_list_next(stat_entry)) {
        if_stat = (if_stat_t *)stat_entry->data;
        pcap_close(if_stat->pch);
        g_free(if_stat->name);
        g_free(if_stat);
    }
    g_list_free(stat_list);
    free_interface_list(if_list);

    return 0;
}


#ifdef _WIN32
static BOOL WINAPI
capture_cleanup_handler(DWORD dwCtrlType)
{
    /* CTRL_C_EVENT is sort of like SIGINT, CTRL_BREAK_EVENT is unique to
       Windows, CTRL_CLOSE_EVENT is sort of like SIGHUP, CTRL_LOGOFF_EVENT
       is also sort of like SIGHUP, and CTRL_SHUTDOWN_EVENT is sort of
       like SIGTERM at least when the machine's shutting down.

       For now, if we're running as a command rather than a capture child,
       we handle all but CTRL_LOGOFF_EVENT as indications that we should
       clean up and quit, just as we handle SIGINT, SIGHUP, and SIGTERM
       in that way on UN*X.

       If we're not running as a capture child, we might be running as
       a service; ignore CTRL_LOGOFF_EVENT, so we keep running after the
       user logs out.  (XXX - can we explicitly check whether we're
       running as a service?) */

    g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO,
        "Console: Control signal");
    g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG,
        "Console: Control signal, CtrlType: %u", dwCtrlType);

    /* Keep capture running if we're a service and a user logs off */
    if (capture_child || (dwCtrlType != CTRL_LOGOFF_EVENT)) {
        capture_loop_stop();
        return TRUE;
    } else {
        return FALSE;
    }
}
#else
static void
capture_cleanup_handler(int signum _U_)
{
    /* On UN*X, we cleanly shut down the capture on SIGINT, SIGHUP, and
       SIGTERM.  We assume that if the user wanted it to keep running
       after they logged out, they'd have nohupped it. */

    /* Note: don't call g_log() in the signal handler: if we happened to be in
     * g_log() in process context when the signal came in, g_log will detect
     * the "recursion" and abort.
     */

    capture_loop_stop();
}
#endif


static void
report_capture_count(gboolean reportit)
{
    /* Don't print this if we're a capture child. */
    if (!capture_child && reportit) {
        fprintf(stderr, "\rPackets captured: %u\n", global_ld.packet_count);
        /* stderr could be line buffered */
        fflush(stderr);
    }
}


#ifdef SIGINFO
static void
report_counts_for_siginfo(void)
{
    report_capture_count(quiet);
    infoprint = FALSE; /* we just reported it */
}

static void
report_counts_siginfo(int signum _U_)
{
    int sav_errno = errno;

    /* If we've been told to delay printing, just set a flag asking
       that we print counts (if we're supposed to), otherwise print
       the count of packets captured (if we're supposed to). */
    if (infodelay)
        infoprint = TRUE;
    else
        report_counts_for_siginfo();
    errno = sav_errno;
}
#endif /* SIGINFO */

static void
exit_main(int status)
{
#ifdef _WIN32
    /* Shutdown windows sockets */
    WSACleanup();

    /* can be helpful for debugging */
#ifdef DEBUG_DUMPCAP
    printf("Press any key\n");
    _getch();
#endif

#endif /* _WIN32 */

    exit(status);
}

#ifdef HAVE_LIBCAP
/*
 * If we were linked with libcap (not related to libpcap), make sure we have
 * CAP_NET_ADMIN and CAP_NET_RAW, then relinquish our permissions.
 * (See comment in main() for details)
 */
static void
relinquish_privs_except_capture(void)
{
    /* If 'started_with_special_privs' (ie: suid) then enable for
     *  ourself the  NET_ADMIN and NET_RAW capabilities and then
     *  drop our suid privileges.
     *
     * CAP_NET_ADMIN: Promiscuous mode and a truckload of other
     *                stuff we don't need (and shouldn't have).
     * CAP_NET_RAW:   Packet capture (raw sockets).
     */

    if (started_with_special_privs()) {
        cap_value_t cap_list[2] = { CAP_NET_ADMIN, CAP_NET_RAW };
        int cl_len = sizeof(cap_list) / sizeof(cap_value_t);

        cap_t caps = cap_init();    /* all capabilities initialized to off */

        print_caps("Pre drop, pre set");

        if (prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) == -1) {
            cmdarg_err("prctl() fail return: %s", g_strerror(errno));
        }

        cap_set_flag(caps, CAP_PERMITTED,   cl_len, cap_list, CAP_SET);
        cap_set_flag(caps, CAP_INHERITABLE, cl_len, cap_list, CAP_SET);

        if (cap_set_proc(caps)) {
            cmdarg_err("cap_set_proc() fail return: %s", g_strerror(errno));
        }
        print_caps("Pre drop, post set");

        relinquish_special_privs_perm();

        print_caps("Post drop, pre set");
        cap_set_flag(caps, CAP_EFFECTIVE,   cl_len, cap_list, CAP_SET);
        if (cap_set_proc(caps)) {
            cmdarg_err("cap_set_proc() fail return: %s", g_strerror(errno));
        }
        print_caps("Post drop, post set");

        cap_free(caps);
    }
}

#endif /* HAVE_LIBCAP */

/* Take care of byte order in the libpcap headers read from pipes.
 * (function taken from wiretap/libpcap.c) */
static void
cap_pipe_adjust_header(gboolean byte_swapped, struct pcap_hdr *hdr, struct pcaprec_hdr *rechdr)
{
    if (byte_swapped) {
        /* Byte-swap the record header fields. */
        rechdr->ts_sec = GUINT32_SWAP_LE_BE(rechdr->ts_sec);
        rechdr->ts_usec = GUINT32_SWAP_LE_BE(rechdr->ts_usec);
        rechdr->incl_len = GUINT32_SWAP_LE_BE(rechdr->incl_len);
        rechdr->orig_len = GUINT32_SWAP_LE_BE(rechdr->orig_len);
    }

    /* In file format version 2.3, the "incl_len" and "orig_len" fields were
       swapped, in order to match the BPF header layout.

       Unfortunately, some files were, according to a comment in the "libpcap"
       source, written with version 2.3 in their headers but without the
       interchanged fields, so if "incl_len" is greater than "orig_len" - which
       would make no sense - we assume that we need to swap them.  */
    if (hdr->version_major == 2 &&
        (hdr->version_minor < 3 ||
         (hdr->version_minor == 3 && rechdr->incl_len > rechdr->orig_len))) {
        guint32 temp;

        temp = rechdr->orig_len;
        rechdr->orig_len = rechdr->incl_len;
        rechdr->incl_len = temp;
    }
}

/* Wrapper: distinguish between recv/read if we're reading on Windows,
 * or just read().
 */
static ssize_t
cap_pipe_read(int pipe_fd, char *buf, size_t sz, gboolean from_socket _U_)
{
#ifdef _WIN32
   if (from_socket) {
      return recv(pipe_fd, buf, (int)sz, 0);
   } else {
      return -1;
   }
#else
   return ws_read(pipe_fd, buf, sz);
#endif
}

#if defined(_WIN32)
/*
 * Thread function that reads from a pipe and pushes the data
 * to the main application thread.
 */
/*
 * XXX Right now we use async queues for basic signaling. The main thread
 * sets cap_pipe_buf and cap_bytes_to_read, then pushes an item onto
 * cap_pipe_pending_q which triggers a read in the cap_pipe_read thread.
 * Iff the read is successful cap_pipe_read pushes an item onto
 * cap_pipe_done_q, otherwise an error is signaled. No data is passed in
 * the queues themselves (yet).
 *
 * We might want to move some of the cap_pipe_dispatch logic here so that
 * we can let cap_thread_read run independently, queuing up multiple reads
 * for the main thread (and possibly get rid of cap_pipe_read_mtx).
 */
static void *cap_thread_read(void *arg)
{
    pcap_options *pcap_opts;
#ifdef _WIN32
    BOOL res;
    DWORD b, last_err, bytes_read;
#else /* _WIN32 */
    size_t bytes_read;
    int b;
#endif /* _WIN32 */

    pcap_opts = (pcap_options *)arg;
    while (pcap_opts->cap_pipe_err == PIPOK) {
        g_async_queue_pop(pcap_opts->cap_pipe_pending_q); /* Wait for our cue (ahem) from the main thread */
        g_mutex_lock(pcap_opts->cap_pipe_read_mtx);
        bytes_read = 0;
        while (bytes_read < pcap_opts->cap_pipe_bytes_to_read) {
           if ((pcap_opts->from_cap_socket)
#ifndef _WIN32
              || 1
#endif
              )
           {
               b = cap_pipe_read(pcap_opts->cap_pipe_fd, pcap_opts->cap_pipe_buf+bytes_read,
                        pcap_opts->cap_pipe_bytes_to_read - bytes_read, pcap_opts->from_cap_socket);
               if (b <= 0) {
                   if (b == 0) {
                       pcap_opts->cap_pipe_err = PIPEOF;
                       bytes_read = 0;
                       break;
                   } else {
                       pcap_opts->cap_pipe_err = PIPERR;
                       bytes_read = -1;
                       break;
                   }
               } else {
                   bytes_read += b;
               }
           }
#ifdef _WIN32
           else
           {
               /* If we try to use read() on a named pipe on Windows with partial
                * data it appears to return EOF.
                */
               res = ReadFile(pcap_opts->cap_pipe_h, pcap_opts->cap_pipe_buf+bytes_read,
                              pcap_opts->cap_pipe_bytes_to_read - bytes_read,
                              &b, NULL);

               bytes_read += b;
               if (!res) {
                   last_err = GetLastError();
                   if (last_err == ERROR_MORE_DATA) {
                       continue;
                   } else if (last_err == ERROR_HANDLE_EOF || last_err == ERROR_BROKEN_PIPE || last_err == ERROR_PIPE_NOT_CONNECTED) {
                       pcap_opts->cap_pipe_err = PIPEOF;
                       bytes_read = 0;
                       break;
                   }
                   pcap_opts->cap_pipe_err = PIPERR;
                   bytes_read = -1;
                   break;
               } else if (b == 0 && pcap_opts->cap_pipe_bytes_to_read > 0) {
                   pcap_opts->cap_pipe_err = PIPEOF;
                   bytes_read = 0;
                   break;
               }
           }
#endif /*_WIN32 */
        }
        pcap_opts->cap_pipe_bytes_read = bytes_read;
        if (pcap_opts->cap_pipe_bytes_read >= pcap_opts->cap_pipe_bytes_to_read) {
            g_async_queue_push(pcap_opts->cap_pipe_done_q, pcap_opts->cap_pipe_buf); /* Any non-NULL value will do */
        }
        g_mutex_unlock(pcap_opts->cap_pipe_read_mtx);
    }
    return NULL;
}
#endif

/* Provide select() functionality for a single file descriptor
 * on UNIX/POSIX. Windows uses cap_pipe_read via a thread.
 *
 * Returns the same values as select.
 */
static int
cap_pipe_select(int pipe_fd)
{
    fd_set      rfds;
    struct timeval timeout;

    FD_ZERO(&rfds);
    FD_SET(pipe_fd, &rfds);

    timeout.tv_sec = PIPE_READ_TIMEOUT / 1000000;
    timeout.tv_usec = PIPE_READ_TIMEOUT % 1000000;

    return select(pipe_fd+1, &rfds, NULL, NULL, &timeout);
}

#define DEF_TCP_PORT 19000

static int
cap_open_socket(char *pipename, pcap_options *pcap_opts, char *errmsg, int errmsgl)
{
  char *sockname = pipename + 4;
  struct sockaddr_in sa;
  char buf[16];
  char *p;
  unsigned long port;
  size_t len;
  int fd;

  memset(&sa, 0, sizeof(sa));

  p = strchr(sockname, ':');
  if (p == NULL) {
    len = strlen(sockname);
    port = DEF_TCP_PORT;
  }
  else {
    len = p - sockname;
    port = strtoul(p + 1, &p, 10);
    if (*p || port > 65535) {
      goto fail_invalid;
    }
  }

  if (len > 15) {
    goto fail_invalid;
  }

  strncpy(buf, sockname, len);
  buf[len] = '\0';
  if (inet_pton(AF_INET, buf, &sa.sin_addr) <= 0) {
    goto fail_invalid;
  }

  sa.sin_family = AF_INET;
  sa.sin_port = htons((u_short)port);

  if (((fd = (int)socket(AF_INET, SOCK_STREAM, 0)) < 0) ||
      (connect(fd, (struct sockaddr *)&sa, sizeof(sa)) < 0)) {
#ifdef _WIN32
      LPTSTR errorText = NULL;
      int lastError;

      lastError = WSAGetLastError();
      FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM |
                    FORMAT_MESSAGE_ALLOCATE_BUFFER |
                    FORMAT_MESSAGE_IGNORE_INSERTS,
                    NULL, lastError, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
                    (LPTSTR)&errorText, 0, NULL);
#endif
      g_snprintf(errmsg, errmsgl,
      "The capture session could not be initiated due to the socket error: \n"
#ifdef _WIN32
      "         %d: %S", lastError, errorText ? (char *)errorText : "Unknown");
      if (errorText)
          LocalFree(errorText);
#else
      "         %d: %s", errno, strerror(errno));
#endif
      pcap_opts->cap_pipe_err = PIPERR;

      if (fd >= 0)
          cap_pipe_close(fd, TRUE);
      return -1;
  }

  pcap_opts->from_cap_socket = TRUE;
  return fd;

fail_invalid:
  g_snprintf(errmsg, errmsgl,
      "The capture session could not be initiated because\n"
      "\"%s\" is not a valid socket specification", pipename);
  pcap_opts->cap_pipe_err = PIPERR;
  return -1;
}

/* Wrapper: distinguish between closesocket on Windows; use ws_close
 * otherwise.
 */
static void
cap_pipe_close(int pipe_fd, gboolean from_socket _U_)
{
#ifdef _WIN32
   if (from_socket) {
      closesocket(pipe_fd);
   }
#else
   ws_close(pipe_fd);
#endif
}

/* Mimic pcap_open_live() for pipe captures

 * We check if "pipename" is "-" (stdin), a AF_UNIX socket, or a FIFO,
 * open it, and read the header.
 *
 * N.B. : we can't read the libpcap formats used in RedHat 6.1 or SuSE 6.3
 * because we can't seek on pipes (see wiretap/libpcap.c for details) */
static void
cap_pipe_open_live(char *pipename,
                   pcap_options *pcap_opts,
                   struct pcap_hdr *hdr,
                   char *errmsg, int errmsgl)
{
#ifndef _WIN32
    ws_statb64         pipe_stat;
    struct sockaddr_un sa;
#else /* _WIN32 */
    char    *pncopy, *pos;
    wchar_t *err_str;
#endif
    ssize_t  b;
    int      fd = -1, sel_ret;
    size_t   bytes_read;
    guint32  magic = 0;

    pcap_opts->cap_pipe_fd = -1;
#ifdef _WIN32
    pcap_opts->cap_pipe_h = INVALID_HANDLE_VALUE;
#endif
    g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "cap_pipe_open_live: %s", pipename);

    /*
     * XXX - this blocks until a pcap per-file header has been written to
     * the pipe, so it could block indefinitely.
     */
    if (strcmp(pipename, "-") == 0) {
#ifndef _WIN32
        fd = 0; /* read from stdin */
#else /* _WIN32 */
        pcap_opts->cap_pipe_h = GetStdHandle(STD_INPUT_HANDLE);
#endif  /* _WIN32 */
    } else if (!strncmp(pipename, "TCP@", 4)) {
       if ((fd = cap_open_socket(pipename, pcap_opts, errmsg, errmsgl)) < 0) {
          return;
       }
    } else {
#ifndef _WIN32
        if (ws_stat64(pipename, &pipe_stat) < 0) {
            if (errno == ENOENT || errno == ENOTDIR)
                pcap_opts->cap_pipe_err = PIPNEXIST;
            else {
                g_snprintf(errmsg, errmsgl,
                           "The capture session could not be initiated "
                           "due to error getting information on pipe/socket: %s", g_strerror(errno));
                pcap_opts->cap_pipe_err = PIPERR;
            }
            return;
        }
        if (S_ISFIFO(pipe_stat.st_mode)) {
            fd = ws_open(pipename, O_RDONLY | O_NONBLOCK, 0000 /* no creation so don't matter */);
            if (fd == -1) {
                g_snprintf(errmsg, errmsgl,
                           "The capture session could not be initiated "
                           "due to error on pipe open: %s", g_strerror(errno));
                pcap_opts->cap_pipe_err = PIPERR;
                return;
            }
        } else if (S_ISSOCK(pipe_stat.st_mode)) {
            fd = socket(AF_UNIX, SOCK_STREAM, 0);
            if (fd == -1) {
                g_snprintf(errmsg, errmsgl,
                           "The capture session could not be initiated "
                           "due to error on socket create: %s", g_strerror(errno));
                pcap_opts->cap_pipe_err = PIPERR;
                return;
            }
            sa.sun_family = AF_UNIX;
            /*
             * The Single UNIX Specification says:
             *
             *   The size of sun_path has intentionally been left undefined.
             *   This is because different implementations use different sizes.
             *   For example, 4.3 BSD uses a size of 108, and 4.4 BSD uses a size
             *   of 104. Since most implementations originate from BSD versions,
             *   the size is typically in the range 92 to 108.
             *
             *   Applications should not assume a particular length for sun_path
             *   or assume that it can hold {_POSIX_PATH_MAX} bytes (256).
             *
             * It also says
             *
             *   The <sys/un.h> header shall define the sockaddr_un structure,
             *   which shall include at least the following members:
             *
             *   sa_family_t  sun_family  Address family.
             *   char         sun_path[]  Socket pathname.
             *
             * so we assume that it's an array, with a specified size,
             * and that the size reflects the maximum path length.
             */
            if (g_strlcpy(sa.sun_path, pipename, sizeof sa.sun_path) > sizeof sa.sun_path) {
                /* Path name too long */
                g_snprintf(errmsg, errmsgl,
                           "The capture session coud not be initiated "
                           "due to error on socket connect: Path name too long");
                pcap_opts->cap_pipe_err = PIPERR;
                ws_close(fd);
                return;
            }
            b = connect(fd, (struct sockaddr *)&sa, sizeof sa);
            if (b == -1) {
                g_snprintf(errmsg, errmsgl,
                           "The capture session coud not be initiated "
                           "due to error on socket connect: %s", g_strerror(errno));
                pcap_opts->cap_pipe_err = PIPERR;
                ws_close(fd);
                return;
            }
        } else {
            if (S_ISCHR(pipe_stat.st_mode)) {
                /*
                 * Assume the user specified an interface on a system where
                 * interfaces are in /dev.  Pretend we haven't seen it.
                 */
                pcap_opts->cap_pipe_err = PIPNEXIST;
            } else {
                g_snprintf(errmsg, errmsgl,
                           "The capture session could not be initiated because\n"
                           "\"%s\" is neither an interface nor a socket nor a pipe", pipename);
                pcap_opts->cap_pipe_err = PIPERR;
            }
            return;
        }
#else /* _WIN32 */
#define PIPE_STR "\\pipe\\"
        /* Under Windows, named pipes _must_ have the form
         * "\\<server>\pipe\<pipename>".  <server> may be "." for localhost.
         */
        pncopy = g_strdup(pipename);
        if ( (pos=strstr(pncopy, "\\\\")) == pncopy) {
            pos = strchr(pncopy + 3, '\\');
            if (pos && g_ascii_strncasecmp(pos, PIPE_STR, strlen(PIPE_STR)) != 0)
                pos = NULL;
        }

        g_free(pncopy);

        if (!pos) {
            g_snprintf(errmsg, errmsgl,
                       "The capture session could not be initiated because\n"
                       "\"%s\" is neither an interface nor a pipe", pipename);
            pcap_opts->cap_pipe_err = PIPNEXIST;
            return;
        }

        /* Wait for the pipe to appear */
        while (1) {
            pcap_opts->cap_pipe_h = CreateFile(utf_8to16(pipename), GENERIC_READ, 0, NULL,
                                               OPEN_EXISTING, 0, NULL);

            if (pcap_opts->cap_pipe_h != INVALID_HANDLE_VALUE)
                break;

            if (GetLastError() != ERROR_PIPE_BUSY) {
                FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_IGNORE_INSERTS,
                              NULL, GetLastError(), 0, (LPTSTR) &err_str, 0, NULL);
                g_snprintf(errmsg, errmsgl,
                           "The capture session on \"%s\" could not be started "
                           "due to error on pipe open: %s (error %d)",
                           pipename, utf_16to8(err_str), GetLastError());
                LocalFree(err_str);
                pcap_opts->cap_pipe_err = PIPERR;
                return;
            }

            if (!WaitNamedPipe(utf_8to16(pipename), 30 * 1000)) {
                FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_IGNORE_INSERTS,
                              NULL, GetLastError(), 0, (LPTSTR) &err_str, 0, NULL);
                g_snprintf(errmsg, errmsgl,
                           "The capture session on \"%s\" timed out during "
                           "pipe open: %s (error %d)",
                           pipename, utf_16to8(err_str), GetLastError());
                LocalFree(err_str);
                pcap_opts->cap_pipe_err = PIPERR;
                return;
            }
        }
#endif /* _WIN32 */
    }

    pcap_opts->from_cap_pipe = TRUE;

#ifdef _WIN32
    if (pcap_opts->from_cap_socket)
#endif
    {
        /* read the pcap header */
        bytes_read = 0;
        while (bytes_read < sizeof magic) {
            if (fd == -1) {
                g_snprintf(errmsg, errmsgl, "Invalid file descriptor");
                goto error;
            }

            sel_ret = cap_pipe_select(fd);
            if (sel_ret < 0) {
                g_snprintf(errmsg, errmsgl,
                           "Unexpected error from select: %s", g_strerror(errno));
                goto error;
            } else if (sel_ret > 0) {
                b = cap_pipe_read(fd, ((char *)&magic)+bytes_read,
                                  sizeof magic-bytes_read,
                                  pcap_opts->from_cap_socket);
                if (b <= 0) {
                    if (b == 0)
                        g_snprintf(errmsg, errmsgl, "End of file on pipe magic during open");
                    else
                        g_snprintf(errmsg, errmsgl, "Error on pipe magic during open: %s",
                                   g_strerror(errno));
                    goto error;
                }
                bytes_read += b;
            }
        }
    }
#ifdef _WIN32
    else {
#if GLIB_CHECK_VERSION(2,31,0)
        g_thread_new("cap_pipe_open_live", &cap_thread_read, pcap_opts);
#else
        g_thread_create(&cap_thread_read, pcap_opts, FALSE, NULL);
#endif

        pcap_opts->cap_pipe_buf = (char *) &magic;
        pcap_opts->cap_pipe_bytes_read = 0;
        pcap_opts->cap_pipe_bytes_to_read = sizeof(magic);
        /* We don't have to worry about cap_pipe_read_mtx here */
        g_async_queue_push(pcap_opts->cap_pipe_pending_q, pcap_opts->cap_pipe_buf);
        g_async_queue_pop(pcap_opts->cap_pipe_done_q);
        if (pcap_opts->cap_pipe_bytes_read <= 0) {
            if (pcap_opts->cap_pipe_bytes_read == 0)
                g_snprintf(errmsg, errmsgl, "End of file on pipe magic during open");
            else
                g_snprintf(errmsg, errmsgl, "Error on pipe magic during open: %s",
                           g_strerror(errno));
            goto error;
        }
    }
#endif

    switch (magic) {
    case PCAP_MAGIC:
    case PCAP_NSEC_MAGIC:
        /* Host that wrote it has our byte order, and was running
           a program using either standard or ss990417 libpcap. */
        pcap_opts->cap_pipe_byte_swapped = FALSE;
        pcap_opts->cap_pipe_modified = FALSE;
        pcap_opts->ts_nsec = magic == PCAP_NSEC_MAGIC;
        break;
    case PCAP_MODIFIED_MAGIC:
        /* Host that wrote it has our byte order, but was running
           a program using either ss990915 or ss991029 libpcap. */
        pcap_opts->cap_pipe_byte_swapped = FALSE;
        pcap_opts->cap_pipe_modified = TRUE;
        break;
    case PCAP_SWAPPED_MAGIC:
    case PCAP_SWAPPED_NSEC_MAGIC:
        /* Host that wrote it has a byte order opposite to ours,
           and was running a program using either standard or
           ss990417 libpcap. */
        pcap_opts->cap_pipe_byte_swapped = TRUE;
        pcap_opts->cap_pipe_modified = FALSE;
        pcap_opts->ts_nsec = magic == PCAP_SWAPPED_NSEC_MAGIC;
        break;
    case PCAP_SWAPPED_MODIFIED_MAGIC:
        /* Host that wrote it out has a byte order opposite to
           ours, and was running a program using either ss990915
           or ss991029 libpcap. */
        pcap_opts->cap_pipe_byte_swapped = TRUE;
        pcap_opts->cap_pipe_modified = TRUE;
        break;
    default:
        /* Not a "libpcap" type we know about. */
        g_snprintf(errmsg, errmsgl, "Unrecognized libpcap format");
        goto error;
    }

#ifdef _WIN32
    if (pcap_opts->from_cap_socket)
#endif
    {
        /* Read the rest of the header */
        bytes_read = 0;
        while (bytes_read < sizeof(struct pcap_hdr)) {
            sel_ret = cap_pipe_select(fd);
            if (sel_ret < 0) {
                g_snprintf(errmsg, errmsgl,
                           "Unexpected error from select: %s", g_strerror(errno));
                goto error;
            } else if (sel_ret > 0) {
                b = cap_pipe_read(fd, ((char *)hdr)+bytes_read,
                                  sizeof(struct pcap_hdr) - bytes_read,
                                  pcap_opts->from_cap_socket);
                if (b <= 0) {
                    if (b == 0)
                        g_snprintf(errmsg, errmsgl, "End of file on pipe header during open");
                    else
                        g_snprintf(errmsg, errmsgl, "Error on pipe header during open: %s",
                                   g_strerror(errno));
                    goto error;
                }
                bytes_read += b;
            }
        }
    }
#ifdef _WIN32
    else {
        pcap_opts->cap_pipe_buf = (char *) hdr;
        pcap_opts->cap_pipe_bytes_read = 0;
        pcap_opts->cap_pipe_bytes_to_read = sizeof(struct pcap_hdr);
        g_async_queue_push(pcap_opts->cap_pipe_pending_q, pcap_opts->cap_pipe_buf);
        g_async_queue_pop(pcap_opts->cap_pipe_done_q);
        if (pcap_opts->cap_pipe_bytes_read <= 0) {
            if (pcap_opts->cap_pipe_bytes_read == 0)
                g_snprintf(errmsg, errmsgl, "End of file on pipe header during open");
            else
                g_snprintf(errmsg, errmsgl, "Error on pipe header header during open: %s",
                           g_strerror(errno));
            goto error;
        }
    }
#endif

    if (pcap_opts->cap_pipe_byte_swapped) {
        /* Byte-swap the header fields about which we care. */
        hdr->version_major = GUINT16_SWAP_LE_BE(hdr->version_major);
        hdr->version_minor = GUINT16_SWAP_LE_BE(hdr->version_minor);
        hdr->snaplen = GUINT32_SWAP_LE_BE(hdr->snaplen);
        hdr->network = GUINT32_SWAP_LE_BE(hdr->network);
    }
    pcap_opts->linktype = hdr->network;

    if (hdr->version_major < 2) {
        g_snprintf(errmsg, errmsgl, "Unable to read old libpcap format");
        goto error;
    }

    pcap_opts->cap_pipe_state = STATE_EXPECT_REC_HDR;
    pcap_opts->cap_pipe_err = PIPOK;
    pcap_opts->cap_pipe_fd = fd;
    return;

error:
    g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "cap_pipe_open_live: error %s", errmsg);
    pcap_opts->cap_pipe_err = PIPERR;
    cap_pipe_close(fd, pcap_opts->from_cap_socket);
    pcap_opts->cap_pipe_fd = -1;
}


/* We read one record from the pipe, take care of byte order in the record
 * header, write the record to the capture file, and update capture statistics. */
static int
cap_pipe_dispatch(loop_data *ld, pcap_options *pcap_opts, guchar *data, char *errmsg, int errmsgl)
{
    struct pcap_pkthdr  phdr;
    enum { PD_REC_HDR_READ, PD_DATA_READ, PD_PIPE_EOF, PD_PIPE_ERR,
           PD_ERR } result;
#ifdef _WIN32
#if !GLIB_CHECK_VERSION(2,31,18)
    GTimeVal  wait_time;
#endif
    gpointer  q_status;
    wchar_t  *err_str;
#endif
    ssize_t   b;

#ifdef LOG_CAPTURE_VERBOSE
    g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "cap_pipe_dispatch");
#endif

    switch (pcap_opts->cap_pipe_state) {

    case STATE_EXPECT_REC_HDR:
#ifdef _WIN32
        if (g_mutex_trylock(pcap_opts->cap_pipe_read_mtx)) {
#endif

            pcap_opts->cap_pipe_state = STATE_READ_REC_HDR;
            pcap_opts->cap_pipe_bytes_to_read = pcap_opts->cap_pipe_modified ?
                sizeof(struct pcaprec_modified_hdr) : sizeof(struct pcaprec_hdr);
            pcap_opts->cap_pipe_bytes_read = 0;

#ifdef _WIN32
            pcap_opts->cap_pipe_buf = (char *) &pcap_opts->cap_pipe_rechdr;
            g_async_queue_push(pcap_opts->cap_pipe_pending_q, pcap_opts->cap_pipe_buf);
            g_mutex_unlock(pcap_opts->cap_pipe_read_mtx);
        }
#endif
        /* Fall through */

    case STATE_READ_REC_HDR:
#ifdef _WIN32
        if (pcap_opts->from_cap_socket)
#endif
        {
            b = cap_pipe_read(pcap_opts->cap_pipe_fd, ((char *)&pcap_opts->cap_pipe_rechdr)+pcap_opts->cap_pipe_bytes_read,
                 pcap_opts->cap_pipe_bytes_to_read - pcap_opts->cap_pipe_bytes_read, pcap_opts->from_cap_socket);
            if (b <= 0) {
                if (b == 0)
                    result = PD_PIPE_EOF;
                else
                    result = PD_PIPE_ERR;
                break;
            }
            pcap_opts->cap_pipe_bytes_read += b;
        }
#ifdef _WIN32
        else {
#if GLIB_CHECK_VERSION(2,31,18)
            q_status = g_async_queue_timeout_pop(pcap_opts->cap_pipe_done_q, PIPE_READ_TIMEOUT);
#else
            g_get_current_time(&wait_time);
            g_time_val_add(&wait_time, PIPE_READ_TIMEOUT);
            q_status = g_async_queue_timed_pop(pcap_opts->cap_pipe_done_q, &wait_time);
#endif
            if (pcap_opts->cap_pipe_err == PIPEOF) {
                result = PD_PIPE_EOF;
                break;
            } else if (pcap_opts->cap_pipe_err == PIPERR) {
                result = PD_PIPE_ERR;
                break;
            }
            if (!q_status) {
                return 0;
            }
        }
#endif
        if (pcap_opts->cap_pipe_bytes_read < pcap_opts->cap_pipe_bytes_to_read)
            return 0;
        result = PD_REC_HDR_READ;
        break;

    case STATE_EXPECT_DATA:
#ifdef _WIN32
        if (g_mutex_trylock(pcap_opts->cap_pipe_read_mtx)) {
#endif

            pcap_opts->cap_pipe_state = STATE_READ_DATA;
            pcap_opts->cap_pipe_bytes_to_read = pcap_opts->cap_pipe_rechdr.hdr.incl_len;
            pcap_opts->cap_pipe_bytes_read = 0;

#ifdef _WIN32
            pcap_opts->cap_pipe_buf = (char *) data;
            g_async_queue_push(pcap_opts->cap_pipe_pending_q, pcap_opts->cap_pipe_buf);
            g_mutex_unlock(pcap_opts->cap_pipe_read_mtx);
        }
#endif
        /* Fall through */

    case STATE_READ_DATA:
#ifdef _WIN32
        if (pcap_opts->from_cap_socket)
#endif
        {
            b = cap_pipe_read(pcap_opts->cap_pipe_fd,
                              data+pcap_opts->cap_pipe_bytes_read,
                              pcap_opts->cap_pipe_bytes_to_read - pcap_opts->cap_pipe_bytes_read,
                              pcap_opts->from_cap_socket);
            if (b <= 0) {
                if (b == 0)
                    result = PD_PIPE_EOF;
                else
                    result = PD_PIPE_ERR;
                break;
            }
            pcap_opts->cap_pipe_bytes_read += b;
        }
#ifdef _WIN32
        else {

#if GLIB_CHECK_VERSION(2,31,18)
            q_status = g_async_queue_timeout_pop(pcap_opts->cap_pipe_done_q, PIPE_READ_TIMEOUT);
#else
            g_get_current_time(&wait_time);
            g_time_val_add(&wait_time, PIPE_READ_TIMEOUT);
            q_status = g_async_queue_timed_pop(pcap_opts->cap_pipe_done_q, &wait_time);
#endif /* GLIB_CHECK_VERSION(2,31,18) */
            if (pcap_opts->cap_pipe_err == PIPEOF) {
                result = PD_PIPE_EOF;
                break;
            } else if (pcap_opts->cap_pipe_err == PIPERR) {
                result = PD_PIPE_ERR;
                break;
            }
            if (!q_status) {
                return 0;
            }
        }
#endif /* _WIN32 */
        if (pcap_opts->cap_pipe_bytes_read < pcap_opts->cap_pipe_bytes_to_read)
            return 0;
        result = PD_DATA_READ;
        break;

    default:
        g_snprintf(errmsg, errmsgl, "cap_pipe_dispatch: invalid state");
        result = PD_ERR;

    } /* switch (pcap_opts->cap_pipe_state) */

    /*
     * We've now read as much data as we were expecting, so process it.
     */
    switch (result) {

    case PD_REC_HDR_READ:
        /* We've read the header. Take care of byte order. */
        cap_pipe_adjust_header(pcap_opts->cap_pipe_byte_swapped, &pcap_opts->cap_pipe_hdr,
                               &pcap_opts->cap_pipe_rechdr.hdr);
        if (pcap_opts->cap_pipe_rechdr.hdr.incl_len > WTAP_MAX_PACKET_SIZE) {
            g_snprintf(errmsg, errmsgl, "Frame %u too long (%d bytes)",
                       ld->packet_count+1, pcap_opts->cap_pipe_rechdr.hdr.incl_len);
            break;
        }

        if (pcap_opts->cap_pipe_rechdr.hdr.incl_len) {
            pcap_opts->cap_pipe_state = STATE_EXPECT_DATA;
            return 0;
        }
        /* no data to read? fall through */

    case PD_DATA_READ:
        /* Fill in a "struct pcap_pkthdr", and process the packet. */
        phdr.ts.tv_sec = pcap_opts->cap_pipe_rechdr.hdr.ts_sec;
        phdr.ts.tv_usec = pcap_opts->cap_pipe_rechdr.hdr.ts_usec;
        phdr.caplen = pcap_opts->cap_pipe_rechdr.hdr.incl_len;
        phdr.len = pcap_opts->cap_pipe_rechdr.hdr.orig_len;

        if (use_threads) {
            capture_loop_queue_packet_cb((u_char *)pcap_opts, &phdr, data);
        } else {
            capture_loop_write_packet_cb((u_char *)pcap_opts, &phdr, data);
        }
        pcap_opts->cap_pipe_state = STATE_EXPECT_REC_HDR;
        return 1;

    case PD_PIPE_EOF:
        pcap_opts->cap_pipe_err = PIPEOF;
        return -1;

    case PD_PIPE_ERR:
#ifdef _WIN32
        FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_IGNORE_INSERTS,
                      NULL, GetLastError(), 0, (LPTSTR) &err_str, 0, NULL);
        g_snprintf(errmsg, errmsgl,
                   "Error reading from pipe: %s (error %d)",
                   utf_16to8(err_str), GetLastError());
        LocalFree(err_str);
#else
        g_snprintf(errmsg, errmsgl, "Error reading from pipe: %s",
                   g_strerror(errno));
#endif
        /* Fall through */
    case PD_ERR:
        break;
    }

    pcap_opts->cap_pipe_err = PIPERR;
    /* Return here rather than inside the switch to prevent GCC warning */
    return -1;
}


/** Open the capture input file (pcap or capture pipe).
 *  Returns TRUE if it succeeds, FALSE otherwise. */
static gboolean
capture_loop_open_input(capture_options *capture_opts, loop_data *ld,
                        char *errmsg, size_t errmsg_len,
                        char *secondary_errmsg, size_t secondary_errmsg_len)
{
    gchar             open_err_str[PCAP_ERRBUF_SIZE];
    gchar             *sync_msg_str;
    interface_options interface_opts;
    pcap_options      *pcap_opts;
    guint             i;
#ifdef _WIN32
    int         err;
    gchar      *sync_secondary_msg_str;
    WORD        wVersionRequested;
    WSADATA     wsaData;
#endif

/* XXX - opening Winsock on tshark? */

    /* Initialize Windows Socket if we are in a WIN32 OS
       This needs to be done before querying the interface for network/netmask */
#ifdef _WIN32
    /* XXX - do we really require 1.1 or earlier?
       Are there any versions that support only 2.0 or higher? */
    wVersionRequested = MAKEWORD(1, 1);
    err = WSAStartup(wVersionRequested, &wsaData);
    if (err != 0) {
        switch (err) {

        case WSASYSNOTREADY:
            g_snprintf(errmsg, (gulong) errmsg_len,
                       "Couldn't initialize Windows Sockets: Network system not ready for network communication");
            break;

        case WSAVERNOTSUPPORTED:
            g_snprintf(errmsg, (gulong) errmsg_len,
                       "Couldn't initialize Windows Sockets: Windows Sockets version %u.%u not supported",
                       LOBYTE(wVersionRequested), HIBYTE(wVersionRequested));
            break;

        case WSAEINPROGRESS:
            g_snprintf(errmsg, (gulong) errmsg_len,
                       "Couldn't initialize Windows Sockets: Blocking operation is in progress");
            break;

        case WSAEPROCLIM:
            g_snprintf(errmsg, (gulong) errmsg_len,
                       "Couldn't initialize Windows Sockets: Limit on the number of tasks supported by this WinSock implementation has been reached");
            break;

        case WSAEFAULT:
            g_snprintf(errmsg, (gulong) errmsg_len,
                       "Couldn't initialize Windows Sockets: Bad pointer passed to WSAStartup");
            break;

        default:
            g_snprintf(errmsg, (gulong) errmsg_len,
                       "Couldn't initialize Windows Sockets: error %d", err);
            break;
        }
        g_snprintf(secondary_errmsg, (gulong) secondary_errmsg_len, please_report);
        return FALSE;
    }
#endif
    if ((use_threads == FALSE) &&
        (capture_opts->ifaces->len > 1)) {
        g_snprintf(errmsg, (gulong) errmsg_len,
                   "Using threads is required for capturing on multiple interfaces!");
        return FALSE;
    }

    for (i = 0; i < capture_opts->ifaces->len; i++) {
        interface_opts = g_array_index(capture_opts->ifaces, interface_options, i);
        pcap_opts = (pcap_options *)g_malloc(sizeof (pcap_options));
        if (pcap_opts == NULL) {
            g_snprintf(errmsg, (gulong) errmsg_len,
                   "Could not allocate memory.");
            return FALSE;
        }
        pcap_opts->received = 0;
        pcap_opts->dropped = 0;
        pcap_opts->flushed = 0;
        pcap_opts->pcap_h = NULL;
#ifdef MUST_DO_SELECT
        pcap_opts->pcap_fd = -1;
#endif
        pcap_opts->pcap_err = FALSE;
        pcap_opts->interface_id = i;
        pcap_opts->tid = NULL;
        pcap_opts->snaplen = 0;
        pcap_opts->linktype = -1;
        pcap_opts->ts_nsec = FALSE;
        pcap_opts->from_cap_pipe = FALSE;
        pcap_opts->from_cap_socket = FALSE;
        memset(&pcap_opts->cap_pipe_hdr, 0, sizeof(struct pcap_hdr));
        memset(&pcap_opts->cap_pipe_rechdr, 0, sizeof(struct pcaprec_modified_hdr));
#ifdef _WIN32
        pcap_opts->cap_pipe_h = INVALID_HANDLE_VALUE;
#endif
        pcap_opts->cap_pipe_fd = -1;
        pcap_opts->cap_pipe_modified = FALSE;
        pcap_opts->cap_pipe_byte_swapped = FALSE;
#ifdef _WIN32
        pcap_opts->cap_pipe_buf = NULL;
#endif
        pcap_opts->cap_pipe_bytes_to_read = 0;
        pcap_opts->cap_pipe_bytes_read = 0;
        pcap_opts->cap_pipe_state = STATE_EXPECT_REC_HDR;
        pcap_opts->cap_pipe_err = PIPOK;
#ifdef _WIN32
#if GLIB_CHECK_VERSION(2,31,0)
        pcap_opts->cap_pipe_read_mtx = g_malloc(sizeof(GMutex));
        g_mutex_init(pcap_opts->cap_pipe_read_mtx);
#else
        pcap_opts->cap_pipe_read_mtx = g_mutex_new();
#endif
        pcap_opts->cap_pipe_pending_q = g_async_queue_new();
        pcap_opts->cap_pipe_done_q = g_async_queue_new();
#endif
        g_array_append_val(ld->pcaps, pcap_opts);

        g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_open_input : %s", interface_opts.name);
        pcap_opts->pcap_h = open_capture_device(&interface_opts, &open_err_str);

        if (pcap_opts->pcap_h != NULL) {
            /* we've opened "iface" as a network device */
#ifdef _WIN32
            /* try to set the capture buffer size */
            if (interface_opts.buffer_size > 1 &&
                pcap_setbuff(pcap_opts->pcap_h, interface_opts.buffer_size * 1024 * 1024) != 0) {
                sync_secondary_msg_str = g_strdup_printf(
                    "The capture buffer size of %d MiB seems to be too high for your machine,\n"
                    "the default of %d MiB will be used.\n"
                    "\n"
                    "Nonetheless, the capture is started.\n",
                    interface_opts.buffer_size, DEFAULT_CAPTURE_BUFFER_SIZE);
                report_capture_error("Couldn't set the capture buffer size!",
                                     sync_secondary_msg_str);
                g_free(sync_secondary_msg_str);
            }
#endif

#if defined(HAVE_PCAP_SETSAMPLING)
            if (interface_opts.sampling_method != CAPTURE_SAMP_NONE) {
                struct pcap_samp *samp;

                if ((samp = pcap_setsampling(pcap_opts->pcap_h)) != NULL) {
                    switch (interface_opts.sampling_method) {
                    case CAPTURE_SAMP_BY_COUNT:
                        samp->method = PCAP_SAMP_1_EVERY_N;
                        break;

                    case CAPTURE_SAMP_BY_TIMER:
                        samp->method = PCAP_SAMP_FIRST_AFTER_N_MS;
                        break;

                    default:
                        sync_msg_str = g_strdup_printf(
                            "Unknown sampling method %d specified,\n"
                            "continue without packet sampling",
                            interface_opts.sampling_method);
                        report_capture_error("Couldn't set the capture "
                                             "sampling", sync_msg_str);
                        g_free(sync_msg_str);
                    }
                    samp->value = interface_opts.sampling_param;
                } else {
                    report_capture_error("Couldn't set the capture sampling",
                                         "Cannot get packet sampling data structure");
                }
            }
#endif

            /* setting the data link type only works on real interfaces */
            if (!set_pcap_linktype(pcap_opts->pcap_h, interface_opts.linktype, interface_opts.name,
                                   errmsg, errmsg_len,
                                   secondary_errmsg, secondary_errmsg_len)) {
                return FALSE;
            }
            pcap_opts->linktype = get_pcap_linktype(pcap_opts->pcap_h, interface_opts.name);
        } else {
            /* We couldn't open "iface" as a network device. */
            /* Try to open it as a pipe */
            cap_pipe_open_live(interface_opts.name, pcap_opts, &pcap_opts->cap_pipe_hdr, errmsg, (int) errmsg_len);

#ifndef _WIN32
            if (pcap_opts->cap_pipe_fd == -1) {
#else
            if (pcap_opts->cap_pipe_h == INVALID_HANDLE_VALUE) {
#endif
                if (pcap_opts->cap_pipe_err == PIPNEXIST) {
                    /* Pipe doesn't exist, so output message for interface */
                    get_capture_device_open_failure_messages(open_err_str,
                                                             interface_opts.name,
                                                             errmsg,
                                                             errmsg_len,
                                                             secondary_errmsg,
                                                             secondary_errmsg_len);
                }
                /*
                 * Else pipe (or file) does exist and cap_pipe_open_live() has
                 * filled in errmsg
                 */
                return FALSE;
            } else {
                /* cap_pipe_open_live() succeeded; don't want
                   error message from pcap_open_live() */
                open_err_str[0] = '\0';
            }
        }

/* XXX - will this work for tshark? */
#ifdef MUST_DO_SELECT
        if (!pcap_opts->from_cap_pipe) {
#ifdef HAVE_PCAP_GET_SELECTABLE_FD
            pcap_opts->pcap_fd = pcap_get_selectable_fd(pcap_opts->pcap_h);
#else
            pcap_opts->pcap_fd = pcap_fileno(pcap_opts->pcap_h);
#endif
        }
#endif

        /* Does "open_err_str" contain a non-empty string?  If so, "pcap_open_live()"
           returned a warning; print it, but keep capturing. */
        if (open_err_str[0] != '\0') {
            sync_msg_str = g_strdup_printf("%s.", open_err_str);
            report_capture_error(sync_msg_str, "");
            g_free(sync_msg_str);
        }
        capture_opts->ifaces = g_array_remove_index(capture_opts->ifaces, i);
        g_array_insert_val(capture_opts->ifaces, i, interface_opts);
    }

    /* If not using libcap: we now can now set euid/egid to ruid/rgid         */
    /*  to remove any suid privileges.                                        */
    /* If using libcap: we can now remove NET_RAW and NET_ADMIN capabilities  */
    /*  (euid/egid have already previously been set to ruid/rgid.             */
    /* (See comment in main() for details)                                    */
#ifndef HAVE_LIBCAP
    relinquish_special_privs_perm();
#else
    relinquish_all_capabilities();
#endif
    return TRUE;
}

/* close the capture input file (pcap or capture pipe) */
static void capture_loop_close_input(loop_data *ld)
{
    guint         i;
    pcap_options *pcap_opts;

    g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_close_input");

    for (i = 0; i < ld->pcaps->len; i++) {
        pcap_opts = g_array_index(ld->pcaps, pcap_options *, i);
        /* if open, close the capture pipe "input file" */
        if (pcap_opts->cap_pipe_fd >= 0) {
            g_assert(pcap_opts->from_cap_pipe);
            cap_pipe_close(pcap_opts->cap_pipe_fd, pcap_opts->from_cap_socket);
            pcap_opts->cap_pipe_fd = -1;
        }
#ifdef _WIN32
        if (pcap_opts->cap_pipe_h != INVALID_HANDLE_VALUE) {
            CloseHandle(pcap_opts->cap_pipe_h);
            pcap_opts->cap_pipe_h = INVALID_HANDLE_VALUE;
        }
#endif
        /* if open, close the pcap "input file" */
        if (pcap_opts->pcap_h != NULL) {
            g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_close_input: closing %p", (void *)pcap_opts->pcap_h);
            pcap_close(pcap_opts->pcap_h);
            pcap_opts->pcap_h = NULL;
        }
    }

    ld->go = FALSE;

#ifdef _WIN32
    /* Shut down windows sockets */
    WSACleanup();
#endif
}


/* init the capture filter */
static initfilter_status_t
capture_loop_init_filter(pcap_t *pcap_h, gboolean from_cap_pipe,
                         const gchar * name, const gchar * cfilter)
{
    struct bpf_program fcode;

    g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_init_filter: %s", cfilter);

    /* capture filters only work on real interfaces */
    if (cfilter && !from_cap_pipe) {
        /* A capture filter was specified; set it up. */
        if (!compile_capture_filter(name, pcap_h, &fcode, cfilter)) {
            /* Treat this specially - our caller might try to compile this
               as a display filter and, if that succeeds, warn the user that
               the display and capture filter syntaxes are different. */
            return INITFILTER_BAD_FILTER;
        }
        if (pcap_setfilter(pcap_h, &fcode) < 0) {
#ifdef HAVE_PCAP_FREECODE
            pcap_freecode(&fcode);
#endif
            return INITFILTER_OTHER_ERROR;
        }
#ifdef HAVE_PCAP_FREECODE
        pcap_freecode(&fcode);
#endif
    }

    return INITFILTER_NO_ERROR;
}


/* set up to write to the already-opened capture output file/files */
static gboolean
capture_loop_init_output(capture_options *capture_opts, loop_data *ld, char *errmsg, int errmsg_len)
{
    int                err;
    guint              i;
    pcap_options      *pcap_opts;
    interface_options  interface_opts;
    gboolean           successful;

    g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_init_output");

    if ((capture_opts->use_pcapng == FALSE) &&
        (capture_opts->ifaces->len > 1)) {
        g_snprintf(errmsg, errmsg_len,
                   "Using PCAPNG is required for capturing on multiple interfaces! Use the -n option.");
        return FALSE;
    }

    /* Set up to write to the capture file. */
    if (capture_opts->multi_files_on) {
        ld->pdh = ringbuf_init_libpcap_fdopen(&err);
    } else {
        ld->pdh = ws_fdopen(ld->save_file_fd, "wb");
        if (ld->pdh == NULL) {
            err = errno;
        }
    }
    if (ld->pdh) {
        if (capture_opts->use_pcapng) {
            char appname[100];
            GString             *os_info_str;

            os_info_str = g_string_new("");
            get_os_version_info(os_info_str);

            g_snprintf(appname, sizeof(appname), "Dumpcap %s", get_ws_vcs_version_info());
            successful = pcapng_write_session_header_block(ld->pdh,
                                (const char *)capture_opts->capture_comment,   /* Comment*/
                                NULL,                        /* HW*/
                                os_info_str->str,            /* OS*/
                                appname,
                                -1,                          /* section_length */
                                &ld->bytes_written,
                                &err);

            for (i = 0; successful && (i < capture_opts->ifaces->len); i++) {
                interface_opts = g_array_index(capture_opts->ifaces, interface_options, i);
                pcap_opts = g_array_index(ld->pcaps, pcap_options *, i);
                if (pcap_opts->from_cap_pipe) {
                    pcap_opts->snaplen = pcap_opts->cap_pipe_hdr.snaplen;
                } else {
                    pcap_opts->snaplen = pcap_snapshot(pcap_opts->pcap_h);
                }
                successful = pcapng_write_interface_description_block(global_ld.pdh,
                                                                      NULL,                       /* OPT_COMMENT       1 */
                                                                      interface_opts.name,        /* IDB_NAME          2 */
                                                                      interface_opts.descr,       /* IDB_DESCRIPTION   3 */
                                                                      interface_opts.cfilter,     /* IDB_FILTER       11 */
                                                                      os_info_str->str,           /* IDB_OS           12 */
                                                                      pcap_opts->linktype,
                                                                      pcap_opts->snaplen,
                                                                      &(global_ld.bytes_written),
                                                                      0,                          /* IDB_IF_SPEED      8 */
                                                                      pcap_opts->ts_nsec ? 9 : 6, /* IDB_TSRESOL       9 */
                                                                      &global_ld.err);
            }

            g_string_free(os_info_str, TRUE);

        } else {
            pcap_opts = g_array_index(ld->pcaps, pcap_options *, 0);
            if (pcap_opts->from_cap_pipe) {
                pcap_opts->snaplen = pcap_opts->cap_pipe_hdr.snaplen;
            } else {
                pcap_opts->snaplen = pcap_snapshot(pcap_opts->pcap_h);
            }
            successful = libpcap_write_file_header(ld->pdh, pcap_opts->linktype, pcap_opts->snaplen,
                                                   pcap_opts->ts_nsec, &ld->bytes_written, &err);
        }
        if (!successful) {
            fclose(ld->pdh);
            ld->pdh = NULL;
        }
    }

    if (ld->pdh == NULL) {
        /* We couldn't set up to write to the capture file. */
        /* XXX - use cf_open_error_message from tshark instead? */
        switch (err) {

        default:
            if (err < 0) {
                g_snprintf(errmsg, errmsg_len,
                           "The file to which the capture would be"
                           " saved (\"%s\") could not be opened: Error %d.",
                           capture_opts->save_file, err);
            } else {
                g_snprintf(errmsg, errmsg_len,
                           "The file to which the capture would be"
                           " saved (\"%s\") could not be opened: %s.",
                           capture_opts->save_file, g_strerror(err));
            }
            break;
        }

        return FALSE;
    }

    return TRUE;
}

static gboolean
capture_loop_close_output(capture_options *capture_opts, loop_data *ld, int *err_close)
{

    unsigned int  i;
    pcap_options *pcap_opts;
    guint64       end_time = create_timestamp();

    g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_close_output");

    if (capture_opts->multi_files_on) {
        return ringbuf_libpcap_dump_close(&capture_opts->save_file, err_close);
    } else {
        if (capture_opts->use_pcapng) {
            for (i = 0; i < global_ld.pcaps->len; i++) {
                pcap_opts = g_array_index(global_ld.pcaps, pcap_options *, i);
                if (!pcap_opts->from_cap_pipe) {
                    guint64 isb_ifrecv, isb_ifdrop;
                    struct pcap_stat stats;

                    if (pcap_stats(pcap_opts->pcap_h, &stats) >= 0) {
                        isb_ifrecv = pcap_opts->received;
                        isb_ifdrop = stats.ps_drop + pcap_opts->dropped + pcap_opts->flushed;
                   } else {
                        isb_ifrecv = G_MAXUINT64;
                        isb_ifdrop = G_MAXUINT64;
                    }
                    pcapng_write_interface_statistics_block(ld->pdh,
                                                            i,
                                                            &ld->bytes_written,
                                                            "Counters provided by dumpcap",
                                                            start_time,
                                                            end_time,
                                                            isb_ifrecv,
                                                            isb_ifdrop,
                                                            err_close);
                }
            }
        }
        if (fclose(ld->pdh) == EOF) {
            if (err_close != NULL) {
                *err_close = errno;
            }
            return (FALSE);
        } else {
            return (TRUE);
        }
    }
}

/* dispatch incoming packets (pcap or capture pipe)
 *
 * Waits for incoming packets to be available, and calls pcap_dispatch()
 * to cause them to be processed.
 *
 * Returns the number of packets which were processed.
 *
 * Times out (returning zero) after CAP_READ_TIMEOUT ms; this ensures that the
 * packet-batching behaviour does not cause packets to get held back
 * indefinitely.
 */
static int
capture_loop_dispatch(loop_data *ld,
                      char *errmsg, int errmsg_len, pcap_options *pcap_opts)
{
    int    inpkts;
    gint   packet_count_before;
    guchar pcap_data[WTAP_MAX_PACKET_SIZE];
#ifndef _WIN32
    int    sel_ret;
#endif

    packet_count_before = ld->packet_count;
    if (pcap_opts->from_cap_pipe) {
        /* dispatch from capture pipe */
#ifdef LOG_CAPTURE_VERBOSE
        g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_dispatch: from capture pipe");
#endif
#ifndef _WIN32
        sel_ret = cap_pipe_select(pcap_opts->cap_pipe_fd);
        if (sel_ret <= 0) {
            if (sel_ret < 0 && errno != EINTR) {
                g_snprintf(errmsg, errmsg_len,
                           "Unexpected error from select: %s", g_strerror(errno));
                report_capture_error(errmsg, please_report);
                ld->go = FALSE;
            }
        } else {
            /*
             * "select()" says we can read from the pipe without blocking
             */
#endif
            inpkts = cap_pipe_dispatch(ld, pcap_opts, pcap_data, errmsg, errmsg_len);
            if (inpkts < 0) {
                ld->go = FALSE;
            }
#ifndef _WIN32
        }
#endif
    }
    else
    {
        /* dispatch from pcap */
#ifdef MUST_DO_SELECT
        /*
         * If we have "pcap_get_selectable_fd()", we use it to get the
         * descriptor on which to select; if that's -1, it means there
         * is no descriptor on which you can do a "select()" (perhaps
         * because you're capturing on a special device, and that device's
         * driver unfortunately doesn't support "select()", in which case
         * we don't do the select - which means it might not be possible
         * to stop a capture until a packet arrives.  If that's unacceptable,
         * plead with whoever supplies the software for that device to add
         * "select()" support, or upgrade to libpcap 0.8.1 or later, and
         * rebuild Wireshark or get a version built with libpcap 0.8.1 or
         * later, so it can use pcap_breakloop().
         */
#ifdef LOG_CAPTURE_VERBOSE
        g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_dispatch: from pcap_dispatch with select");
#endif
        if (pcap_opts->pcap_fd != -1) {
            sel_ret = cap_pipe_select(pcap_opts->pcap_fd);
            if (sel_ret > 0) {
                /*
                 * "select()" says we can read from it without blocking; go for
                 * it.
                 *
                 * We don't have pcap_breakloop(), so we only process one packet
                 * per pcap_dispatch() call, to allow a signal to stop the
                 * processing immediately, rather than processing all packets
                 * in a batch before quitting.
                 */
                if (use_threads) {
                    inpkts = pcap_dispatch(pcap_opts->pcap_h, 1, capture_loop_queue_packet_cb, (u_char *)pcap_opts);
                } else {
                    inpkts = pcap_dispatch(pcap_opts->pcap_h, 1, capture_loop_write_packet_cb, (u_char *)pcap_opts);
                }
                if (inpkts < 0) {
                    if (inpkts == -1) {
                        /* Error, rather than pcap_breakloop(). */
                        pcap_opts->pcap_err = TRUE;
                    }
                    ld->go = FALSE; /* error or pcap_breakloop() - stop capturing */
                }
            } else {
                if (sel_ret < 0 && errno != EINTR) {
                    g_snprintf(errmsg, errmsg_len,
                               "Unexpected error from select: %s", g_strerror(errno));
                    report_capture_error(errmsg, please_report);
                    ld->go = FALSE;
                }
            }
        }
        else
#endif /* MUST_DO_SELECT */
        {
            /* dispatch from pcap without select */
#if 1
#ifdef LOG_CAPTURE_VERBOSE
            g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_dispatch: from pcap_dispatch");
#endif
#ifdef _WIN32
            /*
             * On Windows, we don't support asynchronously telling a process to
             * stop capturing; instead, we check for an indication on a pipe
             * after processing packets.  We therefore process only one packet
             * at a time, so that we can check the pipe after every packet.
             */
            if (use_threads) {
                inpkts = pcap_dispatch(pcap_opts->pcap_h, 1, capture_loop_queue_packet_cb, (u_char *)pcap_opts);
            } else {
                inpkts = pcap_dispatch(pcap_opts->pcap_h, 1, capture_loop_write_packet_cb, (u_char *)pcap_opts);
            }
#else
            if (use_threads) {
                inpkts = pcap_dispatch(pcap_opts->pcap_h, -1, capture_loop_queue_packet_cb, (u_char *)pcap_opts);
            } else {
                inpkts = pcap_dispatch(pcap_opts->pcap_h, -1, capture_loop_write_packet_cb, (u_char *)pcap_opts);
            }
#endif
            if (inpkts < 0) {
                if (inpkts == -1) {
                    /* Error, rather than pcap_breakloop(). */
                    pcap_opts->pcap_err = TRUE;
                }
                ld->go = FALSE; /* error or pcap_breakloop() - stop capturing */
            }
#else /* pcap_next_ex */
#ifdef LOG_CAPTURE_VERBOSE
            g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_dispatch: from pcap_next_ex");
#endif
            /* XXX - this is currently unused, as there is some confusion with pcap_next_ex() vs. pcap_dispatch() */

            /*
             * WinPcap's remote capturing feature doesn't work with pcap_dispatch(),
             * see http://wiki.wireshark.org/CaptureSetup_2fWinPcapRemote
             * This should be fixed in the WinPcap 4.0 alpha release.
             *
             * For reference, an example remote interface:
             * rpcap://[1.2.3.4]/\Device\NPF_{39993D68-7C9B-4439-A329-F2D888DA7C5C}
             */

            /* emulate dispatch from pcap */
            {
                int in;
                struct pcap_pkthdr *pkt_header;
                u_char *pkt_data;

                in = 0;
                while(ld->go &&
                      (in = pcap_next_ex(pcap_opts->pcap_h, &pkt_header, &pkt_data)) == 1) {
                    if (use_threads) {
                        capture_loop_queue_packet_cb((u_char *)pcap_opts, pkt_header, pkt_data);
                    } else {
                        capture_loop_write_packet_cb((u_char *)pcap_opts, pkt_header, pkt_data);
                    }
                }

                if (in < 0) {
                    pcap_opts->pcap_err = TRUE;
                    ld->go = FALSE;
                }
            }
#endif /* pcap_next_ex */
        }
    }

#ifdef LOG_CAPTURE_VERBOSE
    g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_dispatch: %d new packet%s", inpkts, plurality(inpkts, "", "s"));
#endif

    return ld->packet_count - packet_count_before;
}

#ifdef _WIN32
/* Isolate the Universally Unique Identifier from the interface.  Basically, we
 * want to grab only the characters between the '{' and '}' delimiters.
 *
 * Returns a GString that must be freed with g_string_free(). */
static GString *
isolate_uuid(const char *iface)
{
    gchar   *ptr;
    GString *gstr;

    ptr = strchr(iface, '{');
    if (ptr == NULL)
        return g_string_new(iface);
    gstr = g_string_new(ptr + 1);

    ptr = strchr(gstr->str, '}');
    if (ptr == NULL)
        return gstr;

    gstr = g_string_truncate(gstr, ptr - gstr->str);
    return gstr;
}
#endif

/* open the output file (temporary/specified name/ringbuffer/named pipe/stdout) */
/* Returns TRUE if the file opened successfully, FALSE otherwise. */
static gboolean
capture_loop_open_output(capture_options *capture_opts, int *save_file_fd,
                         char *errmsg, int errmsg_len)
{
    char     *tmpname;
    gchar    *capfile_name;
    gchar    *prefix;
    gboolean  is_tempfile;

    g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_open_output: %s",
          (capture_opts->save_file) ? capture_opts->save_file : "(not specified)");

    if (capture_opts->save_file != NULL) {
        /* We return to the caller while the capture is in progress.
         * Therefore we need to take a copy of save_file in
         * case the caller destroys it after we return.
         */
        capfile_name = g_strdup(capture_opts->save_file);

        if (capture_opts->output_to_pipe == TRUE) { /* either "-" or named pipe */
            if (capture_opts->multi_files_on) {
                /* ringbuffer is enabled; that doesn't work with standard output or a named pipe */
                g_snprintf(errmsg, errmsg_len,
                           "Ring buffer requested, but capture is being written to standard output or to a named pipe.");
                g_free(capfile_name);
                return FALSE;
            }
            if (strcmp(capfile_name, "-") == 0) {
                /* write to stdout */
                *save_file_fd = 1;
#ifdef _WIN32
                /* set output pipe to binary mode to avoid Windows text-mode processing (eg: for CR/LF)  */
                _setmode(1, O_BINARY);
#endif
            }
        } /* if (...output_to_pipe ... */

        else {
            if (capture_opts->multi_files_on) {
                /* ringbuffer is enabled */
                *save_file_fd = ringbuf_init(capfile_name,
                                             (capture_opts->has_ring_num_files) ? capture_opts->ring_num_files : 0,
                                             capture_opts->group_read_access);

                /* we need the ringbuf name */
                if (*save_file_fd != -1) {
                    g_free(capfile_name);
                    capfile_name = g_strdup(ringbuf_current_filename());
                }
            } else {
                /* Try to open/create the specified file for use as a capture buffer. */
                *save_file_fd = ws_open(capfile_name, O_RDWR|O_BINARY|O_TRUNC|O_CREAT,
                                        (capture_opts->group_read_access) ? 0640 : 0600);
            }
        }
        is_tempfile = FALSE;
    } else {
        /* Choose a random name for the temporary capture buffer */
        if (global_capture_opts.ifaces->len > 1) {
            prefix = g_strdup_printf("wireshark_%d_interfaces", global_capture_opts.ifaces->len);
        } else {
            gchar *basename;
            basename = g_path_get_basename(g_array_index(global_capture_opts.ifaces, interface_options, 0).console_display_name);
#ifdef _WIN32
            /* use the generic portion of the interface guid to form the basis of the filename */
            if (strncmp("NPF_{", basename, 5)==0)
            {
                /* we have a windows guid style device name, extract the guid digits as the basis of the filename */
                GString *iface;
                iface = isolate_uuid(basename);
                g_free(basename);
                basename = g_strdup(iface->str);
                g_string_free(iface, TRUE);
            }
#endif
            /* generate the temp file name prefix...
             * It would be nice if we could specify a pcapng/pcap filename suffix,
             * create_tempfile() however currently uses mkstemp() which doesn't allow this - one day perhaps*/
            if (capture_opts->use_pcapng) {
                prefix = g_strconcat("wireshark_pcapng_", basename, NULL);
            }else{
                prefix = g_strconcat("wireshark_pcap_", basename, NULL);
            }
            g_free(basename);
        }
        *save_file_fd = create_tempfile(&tmpname, prefix);
        g_free(prefix);
        capfile_name = g_strdup(tmpname);
        is_tempfile = TRUE;
    }

    /* did we fail to open the output file? */
    if (*save_file_fd == -1) {
        if (is_tempfile) {
            g_snprintf(errmsg, errmsg_len,
                       "The temporary file to which the capture would be saved (\"%s\") "
                       "could not be opened: %s.", capfile_name, g_strerror(errno));
        } else {
            if (capture_opts->multi_files_on) {
                ringbuf_error_cleanup();
            }

            g_snprintf(errmsg, errmsg_len,
                       "The file to which the capture would be saved (\"%s\") "
                       "could not be opened: %s.", capfile_name,
                       g_strerror(errno));
        }
        g_free(capfile_name);
        return FALSE;
    }

    if (capture_opts->save_file != NULL) {
        g_free(capture_opts->save_file);
    }
    capture_opts->save_file = capfile_name;
    /* capture_opts.save_file is "g_free"ed later, which is equivalent to
       "g_free(capfile_name)". */

    return TRUE;
}


/* Do the work of handling either the file size or file duration capture
   conditions being reached, and switching files or stopping. */
static gboolean
do_file_switch_or_stop(capture_options *capture_opts,
                       condition *cnd_autostop_files,
                       condition *cnd_autostop_size,
                       condition *cnd_file_duration)
{
    guint              i;
    pcap_options      *pcap_opts;
    interface_options  interface_opts;
    gboolean           successful;

    if (capture_opts->multi_files_on) {
        if (cnd_autostop_files != NULL &&
            cnd_eval(cnd_autostop_files, ++global_ld.autostop_files)) {
            /* no files left: stop here */
            global_ld.go = FALSE;
            return FALSE;
        }

        /* Switch to the next ringbuffer file */
        if (ringbuf_switch_file(&global_ld.pdh, &capture_opts->save_file,
                                &global_ld.save_file_fd, &global_ld.err)) {

            /* File switch succeeded: reset the conditions */
            global_ld.bytes_written = 0;
            if (capture_opts->use_pcapng) {
                char appname[100];
                GString             *os_info_str;

                os_info_str = g_string_new("");
                get_os_version_info(os_info_str);

                g_snprintf(appname, sizeof(appname), "Dumpcap %s", get_ws_vcs_version_info());
                successful = pcapng_write_session_header_block(global_ld.pdh,
                                NULL,                        /* Comment */
                                NULL,                        /* HW */
                                os_info_str->str,            /* OS */
                                appname,
                                                                -1,                          /* section_length */
                                &(global_ld.bytes_written),
                                &global_ld.err);

                for (i = 0; successful && (i < capture_opts->ifaces->len); i++) {
                    interface_opts = g_array_index(capture_opts->ifaces, interface_options, i);
                    pcap_opts = g_array_index(global_ld.pcaps, pcap_options *, i);
                    successful = pcapng_write_interface_description_block(global_ld.pdh,
                                                                          NULL,                       /* OPT_COMMENT       1 */
                                                                          interface_opts.name,        /* IDB_NAME          2 */
                                                                          interface_opts.descr,       /* IDB_DESCRIPTION   3 */
                                                                          interface_opts.cfilter,     /* IDB_FILTER       11 */
                                                                          os_info_str->str,           /* IDB_OS           12 */
                                                                          pcap_opts->linktype,
                                                                          pcap_opts->snaplen,
                                                                          &(global_ld.bytes_written),
                                                                          0,                          /* IDB_IF_SPEED      8 */
                                                                          pcap_opts->ts_nsec ? 9 : 6, /* IDB_TSRESOL       9 */
                                                                          &global_ld.err);
                }

                g_string_free(os_info_str, TRUE);

            } else {
                pcap_opts = g_array_index(global_ld.pcaps, pcap_options *, 0);
                successful = libpcap_write_file_header(global_ld.pdh, pcap_opts->linktype, pcap_opts->snaplen,
                                                       pcap_opts->ts_nsec, &global_ld.bytes_written, &global_ld.err);
            }
            if (!successful) {
                fclose(global_ld.pdh);
                global_ld.pdh = NULL;
                global_ld.go = FALSE;
                return FALSE;
            }
            if (cnd_autostop_size)
                cnd_reset(cnd_autostop_size);
            if (cnd_file_duration)
                cnd_reset(cnd_file_duration);
            fflush(global_ld.pdh);
            if (!quiet)
                report_packet_count(global_ld.inpkts_to_sync_pipe);
            global_ld.inpkts_to_sync_pipe = 0;
            report_new_capture_file(capture_opts->save_file);
        } else {
            /* File switch failed: stop here */
            global_ld.go = FALSE;
            return FALSE;
        }
    } else {
        /* single file, stop now */
        global_ld.go = FALSE;
        return FALSE;
    }
    return TRUE;
}

static void *
pcap_read_handler(void* arg)
{
    pcap_options *pcap_opts;
    char          errmsg[MSG_MAX_LENGTH+1];

    pcap_opts = (pcap_options *)arg;

    g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "Started thread for interface %d.",
          pcap_opts->interface_id);

    while (global_ld.go) {
        /* dispatch incoming packets */
        capture_loop_dispatch(&global_ld, errmsg, sizeof(errmsg), pcap_opts);
    }
    g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "Stopped thread for interface %d.",
          pcap_opts->interface_id);
    g_thread_exit(NULL);
    return (NULL);
}

/* Do the low-level work of a capture.
   Returns TRUE if it succeeds, FALSE otherwise. */
static gboolean
capture_loop_start(capture_options *capture_opts, gboolean *stats_known, struct pcap_stat *stats)
{
#ifdef WIN32
    DWORD              upd_time, cur_time; /* GetTickCount() returns a "DWORD" (which is 'unsigned long') */
#else
    struct timeval     upd_time, cur_time;
#endif
    int                err_close;
    int                inpkts;
    condition         *cnd_file_duration     = NULL;
    condition         *cnd_autostop_files    = NULL;
    condition         *cnd_autostop_size     = NULL;
    condition         *cnd_autostop_duration = NULL;
    gboolean           write_ok;
    gboolean           close_ok;
    gboolean           cfilter_error         = FALSE;
    char               errmsg[MSG_MAX_LENGTH+1];
    char               secondary_errmsg[MSG_MAX_LENGTH+1];
    pcap_options      *pcap_opts;
    interface_options  interface_opts;
    guint              i, error_index        = 0;

    *errmsg           = '\0';
    *secondary_errmsg = '\0';

    /* init the loop data */
    global_ld.go                  = TRUE;
    global_ld.packet_count        = 0;
#ifdef SIGINFO
    global_ld.report_packet_count = FALSE;
#endif
    if (capture_opts->has_autostop_packets)
        global_ld.packet_max      = capture_opts->autostop_packets;
    else
        global_ld.packet_max      = 0;        /* no limit */
    global_ld.inpkts_to_sync_pipe = 0;
    global_ld.err                 = 0;  /* no error seen yet */
    global_ld.pdh                 = NULL;
    global_ld.autostop_files      = 0;
    global_ld.save_file_fd        = -1;

    /* We haven't yet gotten the capture statistics. */
    *stats_known      = FALSE;

    g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "Capture loop starting ...");
    capture_opts_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, capture_opts);

    /* open the "input file" from network interface or capture pipe */
    if (!capture_loop_open_input(capture_opts, &global_ld, errmsg, sizeof(errmsg),
                                 secondary_errmsg, sizeof(secondary_errmsg))) {
        goto error;
    }
    for (i = 0; i < capture_opts->ifaces->len; i++) {
        pcap_opts = g_array_index(global_ld.pcaps, pcap_options *, i);
        interface_opts = g_array_index(capture_opts->ifaces, interface_options, i);
        /* init the input filter from the network interface (capture pipe will do nothing) */
        /*
         * When remote capturing WinPCap crashes when the capture filter
         * is NULL. This might be a bug in WPCap. Therefore we provide an empty
         * string.
         */
        switch (capture_loop_init_filter(pcap_opts->pcap_h, pcap_opts->from_cap_pipe,
                                         interface_opts.name,
                                         interface_opts.cfilter?interface_opts.cfilter:"")) {

        case INITFILTER_NO_ERROR:
            break;

        case INITFILTER_BAD_FILTER:
            cfilter_error = TRUE;
            error_index = i;
            g_snprintf(errmsg, sizeof(errmsg), "%s", pcap_geterr(pcap_opts->pcap_h));
            goto error;

        case INITFILTER_OTHER_ERROR:
            g_snprintf(errmsg, sizeof(errmsg), "Can't install filter (%s).",
                       pcap_geterr(pcap_opts->pcap_h));
            g_snprintf(secondary_errmsg, sizeof(secondary_errmsg), "%s", please_report);
            goto error;
        }
    }

    /* If we're supposed to write to a capture file, open it for output
       (temporary/specified name/ringbuffer) */
    if (capture_opts->saving_to_file) {
        if (!capture_loop_open_output(capture_opts, &global_ld.save_file_fd,
                                      errmsg, sizeof(errmsg))) {
            goto error;
        }

        /* set up to write to the already-opened capture output file/files */
        if (!capture_loop_init_output(capture_opts, &global_ld, errmsg,
                                      sizeof(errmsg))) {
            goto error;
        }

        /* XXX - capture SIGTERM and close the capture, in case we're on a
           Linux 2.0[.x] system and you have to explicitly close the capture
           stream in order to turn promiscuous mode off?  We need to do that
           in other places as well - and I don't think that works all the
           time in any case, due to libpcap bugs. */

        /* Well, we should be able to start capturing.

           Sync out the capture file, so the header makes it to the file system,
           and send a "capture started successfully and capture file created"
           message to our parent so that they'll open the capture file and
           update its windows to indicate that we have a live capture in
           progress. */
        fflush(global_ld.pdh);
        report_new_capture_file(capture_opts->save_file);
    }

    /* initialize capture stop (and alike) conditions */
    init_capture_stop_conditions();
    /* create stop conditions */
    if (capture_opts->has_autostop_filesize) {
        if (capture_opts->autostop_filesize > (((guint32)INT_MAX + 1) / 1000)) {
            capture_opts->autostop_filesize = ((guint32)INT_MAX + 1) / 1000;
        }
        cnd_autostop_size =
            cnd_new(CND_CLASS_CAPTURESIZE, (guint64)capture_opts->autostop_filesize * 1000);
    }
    if (capture_opts->has_autostop_duration)
        cnd_autostop_duration =
            cnd_new(CND_CLASS_TIMEOUT,(gint32)capture_opts->autostop_duration);

    if (capture_opts->multi_files_on) {
        if (capture_opts->has_file_duration)
            cnd_file_duration =
                cnd_new(CND_CLASS_TIMEOUT, capture_opts->file_duration);

        if (capture_opts->has_autostop_files)
            cnd_autostop_files =
                cnd_new(CND_CLASS_CAPTURESIZE, capture_opts->autostop_files);
    }

    /* init the time values */
#ifdef WIN32
    upd_time = GetTickCount();
#else
    gettimeofday(&upd_time, NULL);
#endif
    start_time = create_timestamp();
    g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "Capture loop running!");

    /* WOW, everything is prepared! */
    /* please fasten your seat belts, we will enter now the actual capture loop */
    if (use_threads) {
        pcap_queue = g_async_queue_new();
        pcap_queue_bytes = 0;
        pcap_queue_packets = 0;
        for (i = 0; i < global_ld.pcaps->len; i++) {
            pcap_opts = g_array_index(global_ld.pcaps, pcap_options *, i);
#if GLIB_CHECK_VERSION(2,31,0)
            /* XXX - Add an interface name here? */
            pcap_opts->tid = g_thread_new("Capture read", pcap_read_handler, pcap_opts);
#else
            pcap_opts->tid = g_thread_create(pcap_read_handler, pcap_opts, TRUE, NULL);
#endif
        }
    }
    while (global_ld.go) {
        /* dispatch incoming packets */
        if (use_threads) {
            pcap_queue_element *queue_element;
#if GLIB_CHECK_VERSION(2,31,18)

            g_async_queue_lock(pcap_queue);
            queue_element = (pcap_queue_element *)g_async_queue_timeout_pop_unlocked(pcap_queue, WRITER_THREAD_TIMEOUT);
#else
            GTimeVal write_thread_time;

            g_get_current_time(&write_thread_time);
            g_time_val_add(&write_thread_time, WRITER_THREAD_TIMEOUT);
            g_async_queue_lock(pcap_queue);
            queue_element = (pcap_queue_element *)g_async_queue_timed_pop_unlocked(pcap_queue, &write_thread_time);
#endif
            if (queue_element) {
                pcap_queue_bytes -= queue_element->phdr.caplen;
                pcap_queue_packets -= 1;
            }
            g_async_queue_unlock(pcap_queue);
            if (queue_element) {
                g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO,
                      "Dequeued a packet of length %d captured on interface %d.",
                      queue_element->phdr.caplen, queue_element->pcap_opts->interface_id);

                capture_loop_write_packet_cb((u_char *) queue_element->pcap_opts,
                                             &queue_element->phdr,
                                             queue_element->pd);
                g_free(queue_element->pd);
                g_free(queue_element);
                inpkts = 1;
            } else {
                inpkts = 0;
            }
        } else {
            pcap_opts = g_array_index(global_ld.pcaps, pcap_options *, 0);
            inpkts = capture_loop_dispatch(&global_ld, errmsg,
                                           sizeof(errmsg), pcap_opts);
        }
#ifdef SIGINFO
        /* Were we asked to print packet counts by the SIGINFO handler? */
        if (global_ld.report_packet_count) {
            fprintf(stderr, "%u packet%s captured\n", global_ld.packet_count,
                    plurality(global_ld.packet_count, "", "s"));
            global_ld.report_packet_count = FALSE;
        }
#endif

#ifdef _WIN32
        /* any news from our parent (signal pipe)? -> just stop the capture */
        if (!signal_pipe_check_running()) {
            global_ld.go = FALSE;
        }
#endif

        if (inpkts > 0) {
            global_ld.inpkts_to_sync_pipe += inpkts;

            /* check capture size condition */
            if (cnd_autostop_size != NULL &&
                cnd_eval(cnd_autostop_size, global_ld.bytes_written)) {
                /* Capture size limit reached, do we have another file? */
                if (!do_file_switch_or_stop(capture_opts, cnd_autostop_files,
                                            cnd_autostop_size, cnd_file_duration))
                    continue;
            } /* cnd_autostop_size */
            if (capture_opts->output_to_pipe) {
                fflush(global_ld.pdh);
            }
        } /* inpkts */

        /* Only update once every 500ms so as not to overload slow displays.
         * This also prevents too much context-switching between the dumpcap
         * and wireshark processes.
         */
#define DUMPCAP_UPD_TIME 500

#ifdef WIN32
        cur_time = GetTickCount();  /* Note: wraps to 0 if sys runs for 49.7 days */
        if ((cur_time - upd_time) > DUMPCAP_UPD_TIME) { /* wrap just causes an extra update */
#else
        gettimeofday(&cur_time, NULL);
        if (((guint64)cur_time.tv_sec * 1000000 + cur_time.tv_usec) >
            ((guint64)upd_time.tv_sec * 1000000 + upd_time.tv_usec + DUMPCAP_UPD_TIME*1000)) {
#endif

            upd_time = cur_time;

#if 0
            if (pcap_stats(pch, stats) >= 0) {
                *stats_known = TRUE;
            }
#endif
            /* Let the parent process know. */
            if (global_ld.inpkts_to_sync_pipe) {
                /* do sync here */
                fflush(global_ld.pdh);

                /* Send our parent a message saying we've written out
                   "global_ld.inpkts_to_sync_pipe" packets to the capture file. */
                if (!quiet)
                    report_packet_count(global_ld.inpkts_to_sync_pipe);

                global_ld.inpkts_to_sync_pipe = 0;
            }

            /* check capture duration condition */
            if (cnd_autostop_duration != NULL && cnd_eval(cnd_autostop_duration)) {
                /* The maximum capture time has elapsed; stop the capture. */
                global_ld.go = FALSE;
                continue;
            }

            /* check capture file duration condition */
            if (cnd_file_duration != NULL && cnd_eval(cnd_file_duration)) {
                /* duration limit reached, do we have another file? */
                if (!do_file_switch_or_stop(capture_opts, cnd_autostop_files,
                                            cnd_autostop_size, cnd_file_duration))
                    continue;
            } /* cnd_file_duration */
        }
    }

    g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "Capture loop stopping ...");
    if (use_threads) {
        pcap_queue_element *queue_element;

        for (i = 0; i < global_ld.pcaps->len; i++) {
            pcap_opts = g_array_index(global_ld.pcaps, pcap_options *, i);
            g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "Waiting for thread of interface %u...",
                  pcap_opts->interface_id);
            g_thread_join(pcap_opts->tid);
            g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "Thread of interface %u terminated.",
                  pcap_opts->interface_id);
        }
        while (1) {
            g_async_queue_lock(pcap_queue);
            queue_element = (pcap_queue_element *)g_async_queue_try_pop_unlocked(pcap_queue);
            if (queue_element) {
                pcap_queue_bytes -= queue_element->phdr.caplen;
                pcap_queue_packets -= 1;
            }
            g_async_queue_unlock(pcap_queue);
            if (queue_element == NULL) {
                break;
            }
            g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO,
                  "Dequeued a packet of length %d captured on interface %d.",
                  queue_element->phdr.caplen, queue_element->pcap_opts->interface_id);
            capture_loop_write_packet_cb((u_char *)queue_element->pcap_opts,
                                         &queue_element->phdr,
                                         queue_element->pd);
            g_free(queue_element->pd);
            g_free(queue_element);
            global_ld.inpkts_to_sync_pipe += 1;
            if (capture_opts->output_to_pipe) {
                fflush(global_ld.pdh);
            }
        }
    }


    /* delete stop conditions */
    if (cnd_file_duration != NULL)
        cnd_delete(cnd_file_duration);
    if (cnd_autostop_files != NULL)
        cnd_delete(cnd_autostop_files);
    if (cnd_autostop_size != NULL)
        cnd_delete(cnd_autostop_size);
    if (cnd_autostop_duration != NULL)
        cnd_delete(cnd_autostop_duration);

    /* did we have a pcap (input) error? */
    for (i = 0; i < capture_opts->ifaces->len; i++) {
        pcap_opts = g_array_index(global_ld.pcaps, pcap_options *, i);
        if (pcap_opts->pcap_err) {
            /* On Linux, if an interface goes down while you're capturing on it,
               you'll get a "recvfrom: Network is down" or
               "The interface went down" error (ENETDOWN).
               (At least you will if g_strerror() doesn't show a local translation
               of the error.)

               On FreeBSD and OS X, if a network adapter disappears while
               you're capturing on it, you'll get a "read: Device not configured"
               error (ENXIO).  (See previous parenthetical note.)

               On OpenBSD, you get "read: I/O error" (EIO) in the same case.

               These should *not* be reported to the Wireshark developers. */
            char *cap_err_str;

            cap_err_str = pcap_geterr(pcap_opts->pcap_h);
            if (strcmp(cap_err_str, "recvfrom: Network is down") == 0 ||
                strcmp(cap_err_str, "The interface went down") == 0 ||
                strcmp(cap_err_str, "read: Device not configured") == 0 ||
                strcmp(cap_err_str, "read: I/O error") == 0 ||
                strcmp(cap_err_str, "read error: PacketReceivePacket failed") == 0) {
                report_capture_error("The network adapter on which the capture was being done "
                                     "is no longer running; the capture has stopped.",
                                     "");
            } else {
                g_snprintf(errmsg, sizeof(errmsg), "Error while capturing packets: %s",
                           cap_err_str);
                report_capture_error(errmsg, please_report);
            }
            break;
        } else if (pcap_opts->from_cap_pipe && pcap_opts->cap_pipe_err == PIPERR) {
            report_capture_error(errmsg, "");
            break;
        }
    }
    /* did we have an output error while capturing? */
    if (global_ld.err == 0) {
        write_ok = TRUE;
    } else {
        capture_loop_get_errmsg(errmsg, sizeof(errmsg), capture_opts->save_file,
                                global_ld.err, FALSE);
        report_capture_error(errmsg, please_report);
        write_ok = FALSE;
    }

    if (capture_opts->saving_to_file) {
        /* close the output file */
        close_ok = capture_loop_close_output(capture_opts, &global_ld, &err_close);
    } else
        close_ok = TRUE;

    /* there might be packets not yet notified to the parent */
    /* (do this after closing the file, so all packets are already flushed) */
    if (global_ld.inpkts_to_sync_pipe) {
        if (!quiet)
            report_packet_count(global_ld.inpkts_to_sync_pipe);
        global_ld.inpkts_to_sync_pipe = 0;
    }

    /* If we've displayed a message about a write error, there's no point
       in displaying another message about an error on close. */
    if (!close_ok && write_ok) {
        capture_loop_get_errmsg(errmsg, sizeof(errmsg), capture_opts->save_file, err_close,
                                TRUE);
        report_capture_error(errmsg, "");
    }

    /*
     * XXX We exhibit different behaviour between normal mode and sync mode
     * when the pipe is stdin and not already at EOF.  If we're a child, the
     * parent's stdin isn't closed, so if the user starts another capture,
     * cap_pipe_open_live() will very likely not see the expected magic bytes and
     * will say "Unrecognized libpcap format".  On the other hand, in normal
     * mode, cap_pipe_open_live() will say "End of file on pipe during open".
     */

    report_capture_count(TRUE);

    /* get packet drop statistics from pcap */
    for (i = 0; i < capture_opts->ifaces->len; i++) {
        guint32 received;
        guint32 pcap_dropped = 0;

        pcap_opts = g_array_index(global_ld.pcaps, pcap_options *, i);
        interface_opts = g_array_index(capture_opts->ifaces, interface_options, i);
        received = pcap_opts->received;
        if (pcap_opts->pcap_h != NULL) {
            g_assert(!pcap_opts->from_cap_pipe);
            /* Get the capture statistics, so we know how many packets were dropped. */
            /*
             * Older versions of libpcap didn't set ps_ifdrop on some
             * platforms; initialize it to 0 to handle that.
             */
            stats->ps_ifdrop = 0;
            if (pcap_stats(pcap_opts->pcap_h, stats) >= 0) {
                *stats_known = TRUE;
                /* Let the parent process know. */
                pcap_dropped += stats->ps_drop;
            } else {
                g_snprintf(errmsg, sizeof(errmsg),
                           "Can't get packet-drop statistics: %s",
                           pcap_geterr(pcap_opts->pcap_h));
                report_capture_error(errmsg, please_report);
            }
        }
        report_packet_drops(received, pcap_dropped, pcap_opts->dropped, pcap_opts->flushed, stats->ps_ifdrop, interface_opts.console_display_name);
    }

    /* close the input file (pcap or capture pipe) */
    capture_loop_close_input(&global_ld);

    g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "Capture loop stopped!");

    /* ok, if the write and the close were successful. */
    return write_ok && close_ok;

error:
    if (capture_opts->multi_files_on) {
        /* cleanup ringbuffer */
        ringbuf_error_cleanup();
    } else {
        /* We can't use the save file, and we have no FILE * for the stream
           to close in order to close it, so close the FD directly. */
        if (global_ld.save_file_fd != -1) {
            ws_close(global_ld.save_file_fd);
        }

        /* We couldn't even start the capture, so get rid of the capture
           file. */
        if (capture_opts->save_file != NULL) {
            ws_unlink(capture_opts->save_file);
            g_free(capture_opts->save_file);
        }
    }
    capture_opts->save_file = NULL;
    if (cfilter_error)
        report_cfilter_error(capture_opts, error_index, errmsg);
    else
        report_capture_error(errmsg, secondary_errmsg);

    /* close the input file (pcap or cap_pipe) */
    capture_loop_close_input(&global_ld);

    g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "Capture loop stopped with error");

    return FALSE;
}


static void
capture_loop_stop(void)
{
#ifdef HAVE_PCAP_BREAKLOOP
    guint         i;
    pcap_options *pcap_opts;

    for (i = 0; i < global_ld.pcaps->len; i++) {
        pcap_opts = g_array_index(global_ld.pcaps, pcap_options *, i);
        if (pcap_opts->pcap_h != NULL)
            pcap_breakloop(pcap_opts->pcap_h);
    }
#endif
    global_ld.go = FALSE;
}


static void
capture_loop_get_errmsg(char *errmsg, int errmsglen, const char *fname,
                        int err, gboolean is_close)
{
    switch (err) {

    case ENOSPC:
        g_snprintf(errmsg, errmsglen,
                   "Not all the packets could be written to the file"
                   " to which the capture was being saved\n"
                   "(\"%s\") because there is no space left on the file system\n"
                   "on which that file resides.",
                   fname);
        break;

#ifdef EDQUOT
    case EDQUOT:
        g_snprintf(errmsg, errmsglen,
                   "Not all the packets could be written to the file"
                   " to which the capture was being saved\n"
                   "(\"%s\") because you are too close to, or over,"
                   " your disk quota\n"
                   "on the file system on which that file resides.",
                   fname);
        break;
#endif

    default:
        if (is_close) {
            g_snprintf(errmsg, errmsglen,
                       "The file to which the capture was being saved\n"
                       "(\"%s\") could not be closed: %s.",
                       fname, g_strerror(err));
        } else {
            g_snprintf(errmsg, errmsglen,
                       "An error occurred while writing to the file"
                       " to which the capture was being saved\n"
                       "(\"%s\"): %s.",
                       fname, g_strerror(err));
        }
        break;
    }
}


/* one packet was captured, process it */
static void
capture_loop_write_packet_cb(u_char *pcap_opts_p, const struct pcap_pkthdr *phdr,
                             const u_char *pd)
{
    pcap_options *pcap_opts = (pcap_options *) (void *) pcap_opts_p;
    int           err;
    guint         ts_mul    = pcap_opts->ts_nsec ? 1000000000 : 1000000;

    /* We may be called multiple times from pcap_dispatch(); if we've set
       the "stop capturing" flag, ignore this packet, as we're not
       supposed to be saving any more packets. */
    if (!global_ld.go) {
        pcap_opts->flushed++;
        return;
    }

    if (global_ld.pdh) {
        gboolean successful;

        /* We're supposed to write the packet to a file; do so.
           If this fails, set "ld->go" to FALSE, to stop the capture, and set
           "ld->err" to the error. */
        if (global_capture_opts.use_pcapng) {
            successful = pcapng_write_enhanced_packet_block(global_ld.pdh,
                                                            NULL,
                                                            phdr->ts.tv_sec, (gint32)phdr->ts.tv_usec,
                                                            phdr->caplen, phdr->len,
                                                            pcap_opts->interface_id,
                                                            ts_mul,
                                                            pd, 0,
                                                            &global_ld.bytes_written, &err);
        } else {
            successful = libpcap_write_packet(global_ld.pdh,
                                              phdr->ts.tv_sec, (gint32)phdr->ts.tv_usec,
                                              phdr->caplen, phdr->len,
                                              pd,
                                              &global_ld.bytes_written, &err);
        }
        if (!successful) {
            global_ld.go = FALSE;
            global_ld.err = err;
            pcap_opts->dropped++;
        } else {
#if defined(DEBUG_DUMPCAP) || defined(DEBUG_CHILD_DUMPCAP)
            g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO,
                  "Wrote a packet of length %d captured on interface %u.",
                   phdr->caplen, pcap_opts->interface_id);
#endif
            global_ld.packet_count++;
            pcap_opts->received++;
            /* if the user told us to stop after x packets, do we already have enough? */
            if ((global_ld.packet_max > 0) && (global_ld.packet_count >= global_ld.packet_max)) {
                global_ld.go = FALSE;
            }
        }
    }
}

/* one packet was captured, queue it */
static void
capture_loop_queue_packet_cb(u_char *pcap_opts_p, const struct pcap_pkthdr *phdr,
                             const u_char *pd)
{
    pcap_options       *pcap_opts = (pcap_options *) (void *) pcap_opts_p;
    pcap_queue_element *queue_element;
    gboolean            limit_reached;

    /* We may be called multiple times from pcap_dispatch(); if we've set
       the "stop capturing" flag, ignore this packet, as we're not
       supposed to be saving any more packets. */
    if (!global_ld.go) {
        pcap_opts->flushed++;
        return;
    }

    queue_element = (pcap_queue_element *)g_malloc(sizeof(pcap_queue_element));
    if (queue_element == NULL) {
       pcap_opts->dropped++;
       return;
    }
    queue_element->pcap_opts = pcap_opts;
    queue_element->phdr = *phdr;
    queue_element->pd = (u_char *)g_malloc(phdr->caplen);
    if (queue_element->pd == NULL) {
        pcap_opts->dropped++;
        g_free(queue_element);
        return;
    }
    memcpy(queue_element->pd, pd, phdr->caplen);
    g_async_queue_lock(pcap_queue);
    if (((pcap_queue_byte_limit == 0) || (pcap_queue_bytes < pcap_queue_byte_limit)) &&
        ((pcap_queue_packet_limit == 0) || (pcap_queue_packets < pcap_queue_packet_limit))) {
        limit_reached = FALSE;
        g_async_queue_push_unlocked(pcap_queue, queue_element);
        pcap_queue_bytes += phdr->caplen;
        pcap_queue_packets += 1;
    } else {
        limit_reached = TRUE;
    }
    g_async_queue_unlock(pcap_queue);
    if (limit_reached) {
        pcap_opts->dropped++;
        g_free(queue_element->pd);
        g_free(queue_element);
        g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO,
              "Dropped a packet of length %d captured on interface %u.",
              phdr->caplen, pcap_opts->interface_id);
    } else {
        pcap_opts->received++;
        g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO,
              "Queued a packet of length %d captured on interface %u.",
              phdr->caplen, pcap_opts->interface_id);
    }
    /* I don't want to hold the mutex over the debug output. So the
       output may be wrong */
    g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO,
          "Queue size is now %" G_GINT64_MODIFIER "d bytes (%" G_GINT64_MODIFIER "d packets)",
          pcap_queue_bytes, pcap_queue_packets);
}

static int
set_80211_channel(const char *iface, const char *opt)
{
    int     freq    = 0, type, ret;
    gchar **options = NULL;

    options = g_strsplit_set(opt, ",", 2);

    if (options[0])
        freq = atoi(options[0]);

    if (options[1]) {
        type = ws80211_str_to_chan_type(options[1]);
        if (type == -1) {
            ret = EINVAL;
            goto out;
        }
    }
    else
        type = -1;

    ret = ws80211_init();
    if (ret) {
        cmdarg_err("%d: Failed to init ws80211: %s\n", abs(ret), g_strerror(abs(ret)));
        ret = 2;
        goto out;
    }
    ret = ws80211_set_freq(iface, freq, type);

    if (ret) {
        cmdarg_err("%d: Failed to set channel: %s\n", abs(ret), g_strerror(abs(ret)));
        ret = 2;
        goto out;
    }

    if (capture_child)
        pipe_write_block(2, SP_SUCCESS, NULL);
    ret = 0;

out:
    g_strfreev(options);
    return ret;
}

static void
get_dumpcap_runtime_info(GString *str)
{
    /* Libpcap */
    g_string_append(str, ", ");
    get_runtime_pcap_version(str);

    /* zlib */
#if defined(HAVE_LIBZ) && !defined(_WIN32)
    g_string_append_printf(str, ", with libz %s", zlibVersion());
#endif
}

/* And now our feature presentation... [ fade to music ] */
int
main(int argc, char *argv[])
{
    GString          *comp_info_str;
    GString          *runtime_info_str;
    int               opt;
    static const struct option long_options[] = {
        {(char *)"help", no_argument, NULL, 'h'},
        {(char *)"version", no_argument, NULL, 'v'},
        LONGOPT_CAPTURE_COMMON
        {0, 0, 0, 0 }
    };

    gboolean          arg_error             = FALSE;

#ifdef _WIN32
    WSADATA           wsaData;
#else
    struct sigaction  action, oldaction;
#endif

    gboolean          start_capture         = TRUE;
    gboolean          stats_known;
    struct pcap_stat  stats;
    GLogLevelFlags    log_flags;
    gboolean          list_interfaces       = FALSE;
    gboolean          list_link_layer_types = FALSE;
#ifdef HAVE_BPF_IMAGE
    gboolean          print_bpf_code        = FALSE;
#endif
    gboolean          set_chan              = FALSE;
    gchar            *set_chan_arg          = NULL;
    gboolean          machine_readable      = FALSE;
    gboolean          print_statistics      = FALSE;
    int               status, run_once_args = 0;
    gint              i;
    guint             j;
#if defined(__APPLE__) && defined(__LP64__)
    struct utsname    osinfo;
#endif
    GString          *str;

    cmdarg_err_init(dumpcap_cmdarg_err, dumpcap_cmdarg_err_cont);

    /* Assemble the compile-time version information string */
    comp_info_str = g_string_new("Compiled ");
    get_compiled_version_info(comp_info_str, NULL, NULL);

    /* Assemble the run-time version information string */
    runtime_info_str = g_string_new("Running ");
    get_runtime_version_info(runtime_info_str, get_dumpcap_runtime_info);

    /* Add it to the information to be reported on a crash. */
    ws_add_crash_info("Dumpcap %s\n"
           "\n"
           "%s"
           "\n"
           "%s",
        get_ws_vcs_version_info(), comp_info_str->str, runtime_info_str->str);

#ifdef _WIN32
    arg_list_utf_16to8(argc, argv);
    create_app_running_mutex();

    /*
     * Initialize our DLL search path. MUST be called before LoadLibrary
     * or g_module_open.
     */
    ws_init_dll_search_path();
#endif

#ifdef HAVE_BPF_IMAGE
#define OPTSTRING_d "d"
#else
#define OPTSTRING_d ""
#endif

#ifdef HAVE_PCAP_REMOTE
#define OPTSTRING_r "r"
#define OPTSTRING_u "u"
#else
#define OPTSTRING_r ""
#define OPTSTRING_u ""
#endif

#ifdef HAVE_PCAP_SETSAMPLING
#define OPTSTRING_m "m:"
#else
#define OPTSTRING_m ""
#endif

#define OPTSTRING OPTSTRING_CAPTURE_COMMON "C:" OPTSTRING_d "gh" "k:" OPTSTRING_m "MN:nPq" OPTSTRING_r "St" OPTSTRING_u "vw:Z:"

#ifdef DEBUG_CHILD_DUMPCAP
    if ((debug_log = ws_fopen("dumpcap_debug_log.tmp","w")) == NULL) {
        fprintf (stderr, "Unable to open debug log file !\n");
        exit (1);
    }
#endif

#if defined(__APPLE__) && defined(__LP64__)
    /*
     * Is this Mac OS X 10.6.0, 10.6.1, 10.6.3, or 10.6.4?  If so, we need
     * a bug workaround - timeouts less than 1 second don't work with libpcap
     * in 64-bit code.  (The bug was introduced in 10.6, fixed in 10.6.2,
     * re-introduced in 10.6.3, not fixed in 10.6.4, and fixed in 10.6.5.
     * The problem is extremely unlikely to be reintroduced in a future
     * release.)
     */
    if (uname(&osinfo) == 0) {
        /*
         * Mac OS X 10.x uses Darwin {x+4}.0.0.  Mac OS X 10.x.y uses Darwin
         * {x+4}.y.0 (except that 10.6.1 appears to have a uname version
         * number of 10.0.0, not 10.1.0 - go figure).
         */
        if (strcmp(osinfo.release, "10.0.0") == 0 ||    /* 10.6, 10.6.1 */
            strcmp(osinfo.release, "10.3.0") == 0 ||    /* 10.6.3 */
            strcmp(osinfo.release, "10.4.0") == 0)              /* 10.6.4 */
            need_timeout_workaround = TRUE;
    }
#endif

    /*
     * Determine if dumpcap is being requested to run in a special
     * capture_child mode by going thru the command line args to see if
     * a -Z is present. (-Z is a hidden option).
     *
     * The primary result of running in capture_child mode is that
     * all messages sent out on stderr are in a special type/len/string
     * format to allow message processing by type.  These messages include
     * error messages if dumpcap fails to start the operation it was
     * requested to do, as well as various "status" messages which are sent
     * when an actual capture is in progress, and a "success" message sent
     * if dumpcap was requested to perform an operation other than a
     * capture.
     *
     * Capture_child mode would normally be requested by a parent process
     * which invokes dumpcap and obtains dumpcap stderr output via a pipe
     * to which dumpcap stderr has been redirected.  It might also have
     * another pipe to obtain dumpcap stdout output; for operations other
     * than a capture, that information is formatted specially for easier
     * parsing by the parent process.
     *
     * Capture_child mode needs to be determined immediately upon
     * startup so that any messages generated by dumpcap in this mode
     * (eg: during initialization) will be formatted properly.
     */

    for (i=1; i<argc; i++) {
        if (strcmp("-Z", argv[i]) == 0) {
            capture_child    = TRUE;
            machine_readable = TRUE;  /* request machine-readable output */
#ifdef _WIN32
            /* set output pipe to binary mode, to avoid ugly text conversions */
            _setmode(2, O_BINARY);
#endif
        }
    }

    /* The default_log_handler will use stdout, which makes trouble in   */
    /* capture child mode, as it uses stdout for its sync_pipe.          */
    /* So: the filtering is done in the console_log_handler and not here.*/
    /* We set the log handlers right up front to make sure that any log  */
    /* messages when running as child will be sent back to the parent    */
    /* with the correct format.                                          */

    log_flags =
        (GLogLevelFlags)(
        G_LOG_LEVEL_ERROR|
        G_LOG_LEVEL_CRITICAL|
        G_LOG_LEVEL_WARNING|
        G_LOG_LEVEL_MESSAGE|
        G_LOG_LEVEL_INFO|
        G_LOG_LEVEL_DEBUG|
        G_LOG_FLAG_FATAL|
        G_LOG_FLAG_RECURSION);

    g_log_set_handler(NULL,
                      log_flags,
                      console_log_handler, NULL /* user_data */);
    g_log_set_handler(LOG_DOMAIN_MAIN,
                      log_flags,
                      console_log_handler, NULL /* user_data */);
    g_log_set_handler(LOG_DOMAIN_CAPTURE,
                      log_flags,
                      console_log_handler, NULL /* user_data */);
    g_log_set_handler(LOG_DOMAIN_CAPTURE_CHILD,
                      log_flags,
                      console_log_handler, NULL /* user_data */);

    /* Initialize the pcaps list */
    global_ld.pcaps = g_array_new(FALSE, FALSE, sizeof(pcap_options *));

#if !GLIB_CHECK_VERSION(2,31,0)
    /* Initialize the thread system */
    g_thread_init(NULL);
#endif

#ifdef _WIN32
    /* Load wpcap if possible. Do this before collecting the run-time version information */
    load_wpcap();

    /* ... and also load the packet.dll from wpcap */
    /* XXX - currently not required, may change later. */
    /*wpcap_packet_load();*/

    /* Start windows sockets */
    WSAStartup( MAKEWORD( 1, 1 ), &wsaData );

    /* Set handler for Ctrl+C key */
    SetConsoleCtrlHandler(capture_cleanup_handler, TRUE);
#else
    /* Catch SIGINT and SIGTERM and, if we get either of them, clean up
       and exit.  Do the same with SIGPIPE, in case, for example,
       we're writing to our standard output and it's a pipe.
       Do the same with SIGHUP if it's not being ignored (if we're
       being run under nohup, it might be ignored, in which case we
       should leave it ignored).

       XXX - apparently, Coverity complained that part of action
       wasn't initialized.  Perhaps it's running on Linux, where
       struct sigaction has an ignored "sa_restorer" element and
       where "sa_handler" and "sa_sigaction" might not be two
       members of a union. */
    memset(&action, 0, sizeof(action));
    action.sa_handler = capture_cleanup_handler;
    /*
     * Arrange that system calls not get restarted, because when
     * our signal handler returns we don't want to restart
     * a call that was waiting for packets to arrive.
     */
    action.sa_flags = 0;
    sigemptyset(&action.sa_mask);
    sigaction(SIGTERM, &action, NULL);
    sigaction(SIGINT, &action, NULL);
    sigaction(SIGPIPE, &action, NULL);
    sigaction(SIGHUP, NULL, &oldaction);
    if (oldaction.sa_handler == SIG_DFL)
        sigaction(SIGHUP, &action, NULL);

#ifdef SIGINFO
    /* Catch SIGINFO and, if we get it and we're capturing in
       quiet mode, report the number of packets we've captured. */
    action.sa_handler = report_counts_siginfo;
    action.sa_flags = SA_RESTART;
    sigemptyset(&action.sa_mask);
    sigaction(SIGINFO, &action, NULL);
#endif /* SIGINFO */
#endif  /* _WIN32 */

#ifdef __linux__
    enable_kernel_bpf_jit_compiler();
#endif

    /* ----------------------------------------------------------------- */
    /* Privilege and capability handling                                 */
    /* Cases:                                                            */
    /* 1. Running not as root or suid root; no special capabilities.     */
    /*    Action: none                                                   */
    /*                                                                   */
    /* 2. Running logged in as root (euid=0; ruid=0); Not using libcap.  */
    /*    Action: none                                                   */
    /*                                                                   */
    /* 3. Running logged in as root (euid=0; ruid=0). Using libcap.      */
    /*    Action:                                                        */
    /*      - Near start of program: Enable NET_RAW and NET_ADMIN        */
    /*        capabilities; Drop all other capabilities;                 */
    /*      - If not -w  (ie: doing -S or -D, etc) run to completion;    */
    /*        else: after  pcap_open_live() in capture_loop_open_input() */
    /*         drop all capabilities (NET_RAW and NET_ADMIN);            */
    /*         (Note: this means that the process, although logged in    */
    /*          as root, does not have various permissions such as the   */
    /*          ability to bypass file access permissions).              */
    /*      XXX: Should we just leave capabilities alone in this case    */
    /*          so that user gets expected effect that root can do       */
    /*          anything ??                                              */
    /*                                                                   */
    /* 4. Running as suid root (euid=0, ruid=n); Not using libcap.       */
    /*    Action:                                                        */
    /*      - If not -w  (ie: doing -S or -D, etc) run to completion;    */
    /*        else: after  pcap_open_live() in capture_loop_open_input() */
    /*         drop suid root (set euid=ruid).(ie: keep suid until after */
    /*         pcap_open_live).                                          */
    /*                                                                   */
    /* 5. Running as suid root (euid=0, ruid=n); Using libcap.           */
    /*    Action:                                                        */
    /*      - Near start of program: Enable NET_RAW and NET_ADMIN        */
    /*        capabilities; Drop all other capabilities;                 */
    /*        Drop suid privileges (euid=ruid);                          */
    /*      - If not -w  (ie: doing -S or -D, etc) run to completion;    */
    /*        else: after  pcap_open_live() in capture_loop_open_input() */
    /*         drop all capabilities (NET_RAW and NET_ADMIN).            */
    /*                                                                   */
    /*      XXX: For some Linux versions/distros with capabilities       */
    /*        a 'normal' process with any capabilities cannot be         */
    /*        'killed' (signaled) from another (same uid) non-privileged */
    /*        process.                                                   */
    /*        For example: If (non-suid) Wireshark forks a               */
    /*        child suid dumpcap which acts as described here (case 5),  */
    /*        Wireshark will be unable to kill (signal) the child        */
    /*        dumpcap process until the capabilities have been dropped   */
    /*        (after pcap_open_live()).                                  */
    /*        This behaviour will apparently be changed in the kernel    */
    /*        to allow the kill (signal) in this case.                   */
    /*        See the following for details:                             */
    /*           http://www.mail-archive.com/  [wrapped]                 */
    /*             linux-security-module@vger.kernel.org/msg02913.html   */
    /*                                                                   */
    /*        It is therefore conceivable that if dumpcap somehow hangs  */
    /*        in pcap_open_live or before that wireshark will not        */
    /*        be able to stop dumpcap using a signal (INT, TERM, etc).   */
    /*        In this case, exiting wireshark will kill the child        */
    /*        dumpcap process.                                           */
    /*                                                                   */
    /* 6. Not root or suid root; Running with NET_RAW & NET_ADMIN        */
    /*     capabilities; Using libcap.  Note: capset cmd (which see)     */
    /*     used to assign capabilities to file.                          */
    /*    Action:                                                        */
    /*      - If not -w  (ie: doing -S or -D, etc) run to completion;    */
    /*        else: after  pcap_open_live() in capture_loop_open_input() */
    /*         drop all capabilities (NET_RAW and NET_ADMIN)             */
    /*                                                                   */
    /* ToDo: -S (stats) should drop privileges/capabilities when no      */
    /*       longer required (similar to capture).                       */
    /*                                                                   */
    /* ----------------------------------------------------------------- */

    init_process_policies();

#ifdef HAVE_LIBCAP
    /* If 'started with special privileges' (and using libcap)  */
    /*   Set to keep only NET_RAW and NET_ADMIN capabilities;   */
    /*   Set euid/egid = ruid/rgid to remove suid privileges    */
    relinquish_privs_except_capture();
#endif

    /* Set the initial values in the capture options. This might be overwritten
       by the command line parameters. */
    capture_opts_init(&global_capture_opts);

    /* We always save to a file - if no file was specified, we save to a
       temporary file. */
    global_capture_opts.saving_to_file      = TRUE;
    global_capture_opts.has_ring_num_files  = TRUE;

    /* Pass on capture_child mode for capture_opts */
    global_capture_opts.capture_child = capture_child;

    /* Now get our args */
    while ((opt = getopt_long(argc, argv, OPTSTRING, long_options, NULL)) != -1) {
        switch (opt) {
        case 'h':        /* Print help and exit */
            print_usage(TRUE);
            exit_main(0);
            break;
        case 'v':        /* Show version and exit */
        {
            show_version(comp_info_str, runtime_info_str);
            g_string_free(comp_info_str, TRUE);
            g_string_free(runtime_info_str, TRUE);
            exit_main(0);
            break;
        }
        /*** capture option specific ***/
        case 'a':        /* autostop criteria */
        case 'b':        /* Ringbuffer option */
        case 'c':        /* Capture x packets */
        case 'f':        /* capture filter */
        case 'g':        /* enable group read access on file(s) */
        case 'i':        /* Use interface x */
        case 'n':        /* Use pcapng format */
        case 'p':        /* Don't capture in promiscuous mode */
        case 'P':        /* Use pcap format */
        case 's':        /* Set the snapshot (capture) length */
        case 'w':        /* Write to capture file x */
        case 'y':        /* Set the pcap data link type */
        case  LONGOPT_NUM_CAP_COMMENT: /* add a capture comment */
#ifdef HAVE_PCAP_REMOTE
        case 'u':        /* Use UDP for data transfer */
        case 'r':        /* Capture own RPCAP traffic too */
        case 'A':        /* Authentication */
#endif
#ifdef HAVE_PCAP_SETSAMPLING
        case 'm':        /* Sampling */
#endif
#if defined(_WIN32) || defined(HAVE_PCAP_CREATE)
        case 'B':        /* Buffer size */
#endif /* _WIN32 or HAVE_PCAP_CREATE */
#ifdef HAVE_PCAP_CREATE
        case 'I':        /* Monitor mode */
#endif
            status = capture_opts_add_opt(&global_capture_opts, opt, optarg, &start_capture);
            if (status != 0) {
                exit_main(status);
            }
            break;
            /*** hidden option: Wireshark child mode (using binary output messages) ***/
        case 'Z':
            capture_child = TRUE;
#ifdef _WIN32
            /* set output pipe to binary mode, to avoid ugly text conversions */
            _setmode(2, O_BINARY);
            /*
             * optarg = the control ID, aka the PPID, currently used for the
             * signal pipe name.
             */
            if (strcmp(optarg, SIGNAL_PIPE_CTRL_ID_NONE) != 0) {
                sig_pipe_name = g_strdup_printf(SIGNAL_PIPE_FORMAT, optarg);
                sig_pipe_handle = CreateFile(utf_8to16(sig_pipe_name),
                                             GENERIC_READ, 0, NULL, OPEN_EXISTING, 0, NULL);

                if (sig_pipe_handle == INVALID_HANDLE_VALUE) {
                    g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO,
                          "Signal pipe: Unable to open %s.  Dead parent?",
                          sig_pipe_name);
                    exit_main(1);
                }
            }
#endif
            break;

        case 'q':        /* Quiet */
            quiet = TRUE;
            break;
        case 't':
            use_threads = TRUE;
            break;
            /*** all non capture option specific ***/
        case 'D':        /* Print a list of capture devices and exit */
            list_interfaces = TRUE;
            run_once_args++;
            break;
        case 'L':        /* Print list of link-layer types and exit */
            list_link_layer_types = TRUE;
            run_once_args++;
            break;
#ifdef HAVE_BPF_IMAGE
        case 'd':        /* Print BPF code for capture filter and exit */
            print_bpf_code = TRUE;
            run_once_args++;
            break;
#endif
        case 'S':        /* Print interface statistics once a second */
            print_statistics = TRUE;
            run_once_args++;
            break;
        case 'k':        /* Set wireless channel */
            set_chan = TRUE;
            set_chan_arg = optarg;
            run_once_args++;
           break;
        case 'M':        /* For -D, -L, and -S, print machine-readable output */
            machine_readable = TRUE;
            break;
        case 'C':
            pcap_queue_byte_limit = get_positive_int(optarg, "byte_limit");
            break;
        case 'N':
            pcap_queue_packet_limit = get_positive_int(optarg, "packet_limit");
            break;
        default:
            cmdarg_err("Invalid Option: %s", argv[optind-1]);
            /* FALLTHROUGH */
        case '?':        /* Bad flag - print usage message */
            arg_error = TRUE;
            break;
        }
    }
    if (!arg_error) {
        argc -= optind;
        argv += optind;
        if (argc >= 1) {
            /* user specified file name as regular command-line argument */
            /* XXX - use it as the capture file name (or something else)? */
            argc--;
            argv++;
        }
        if (argc != 0) {
            /*
             * Extra command line arguments were specified; complain.
             * XXX - interpret as capture filter, as tcpdump and tshark do?
             */
            cmdarg_err("Invalid argument: %s", argv[0]);
            arg_error = TRUE;
        }
    }

    if ((pcap_queue_byte_limit > 0) || (pcap_queue_packet_limit > 0)) {
        use_threads = TRUE;
    }
    if ((pcap_queue_byte_limit == 0) && (pcap_queue_packet_limit == 0)) {
        /* Use some default if the user hasn't specified some */
        /* XXX: Are these defaults good enough? */
        pcap_queue_byte_limit = 1000 * 1000;
        pcap_queue_packet_limit = 1000;
    }
    if (arg_error) {
        print_usage(FALSE);
        exit_main(1);
    }

    if (run_once_args > 1) {
        cmdarg_err("Only one of -D, -L, or -S may be supplied.");
        exit_main(1);
    } else if (run_once_args == 1) {
        /* We're supposed to print some information, rather than
           to capture traffic; did they specify a ring buffer option? */
        if (global_capture_opts.multi_files_on) {
            cmdarg_err("Ring buffer requested, but a capture isn't being done.");
            exit_main(1);
        }
    } else {
        /* We're supposed to capture traffic; */

        /* Are we capturing on multiple interface? If so, use threads and pcapng. */
        if (global_capture_opts.ifaces->len > 1) {
            use_threads = TRUE;
            global_capture_opts.use_pcapng = TRUE;
        }

        if (global_capture_opts.capture_comment &&
            (!global_capture_opts.use_pcapng || global_capture_opts.multi_files_on)) {
            /* XXX - for ringbuffer, should we apply the comment to each file? */
            cmdarg_err("A capture comment can only be set if we capture into a single pcapng file.");
            exit_main(1);
        }

        /* Was the ring buffer option specified and, if so, does it make sense? */
        if (global_capture_opts.multi_files_on) {
            /* Ring buffer works only under certain conditions:
               a) ring buffer does not work with temporary files;
               b) it makes no sense to enable the ring buffer if the maximum
               file size is set to "infinite". */
            if (global_capture_opts.save_file == NULL) {
                cmdarg_err("Ring buffer requested, but capture isn't being saved to a permanent file.");
                global_capture_opts.multi_files_on = FALSE;
            }
            if (!global_capture_opts.has_autostop_filesize && !global_capture_opts.has_file_duration) {
                cmdarg_err("Ring buffer requested, but no maximum capture file size or duration were specified.");
#if 0
                /* XXX - this must be redesigned as the conditions changed */
                global_capture_opts.multi_files_on = FALSE;
#endif
            }
        }
    }

    /*
     * "-D" requires no interface to be selected; it's supposed to list
     * all interfaces.
     */
    if (list_interfaces) {
        /* Get the list of interfaces */
        GList *if_list;
        int    err;
        gchar *err_str;

        if_list = capture_interface_list(&err, &err_str,NULL);
        if (if_list == NULL) {
            switch (err) {
            case CANT_GET_INTERFACE_LIST:
            case DONT_HAVE_PCAP:
                cmdarg_err("%s", err_str);
                g_free(err_str);
                exit_main(2);
                break;

            case NO_INTERFACES_FOUND:
                /*
                 * If we're being run by another program, just give them
                 * an empty list of interfaces, don't report this as
                 * an error; that lets them decide whether to report
                 * this as an error or not.
                 */
                if (!machine_readable) {
                    cmdarg_err("There are no interfaces on which a capture can be done");
                    exit_main(2);
                }
                break;
            }
        }

        if (machine_readable)      /* tab-separated values to stdout */
            print_machine_readable_interfaces(if_list);
        else
            capture_opts_print_interfaces(if_list);
        free_interface_list(if_list);
        exit_main(0);
    }

    /*
     * "-S" requires no interface to be selected; it gives statistics
     * for all interfaces.
     */
    if (print_statistics) {
        status = print_statistics_loop(machine_readable);
        exit_main(status);
    }

    if (set_chan) {
        interface_options interface_opts;

        if (global_capture_opts.ifaces->len != 1) {
            cmdarg_err("Need one interface");
            exit_main(2);
        }

        interface_opts = g_array_index(global_capture_opts.ifaces, interface_options, 0);
        status = set_80211_channel(interface_opts.name, set_chan_arg);
        exit_main(status);
    }

    /*
     * "-L", "-d", and capturing act on a particular interface, so we have to
     * have an interface; if none was specified, pick a default.
     */
    status = capture_opts_default_iface_if_necessary(&global_capture_opts, NULL);
    if (status != 0) {
        /* cmdarg_err() already called .... */
        exit_main(status);
    }

    /* Let the user know what interfaces were chosen. */
    if (capture_child) {
        for (j = 0; j < global_capture_opts.ifaces->len; j++) {
            interface_options interface_opts;

            interface_opts = g_array_index(global_capture_opts.ifaces, interface_options, j);
            g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "Interface: %s\n",
                  interface_opts.name);
        }
    } else {
        str = g_string_new("");
#ifdef _WIN32
        if (global_capture_opts.ifaces->len < 2)
#else
        if (global_capture_opts.ifaces->len < 4)
#endif
        {
            for (j = 0; j < global_capture_opts.ifaces->len; j++) {
                interface_options interface_opts;

                interface_opts = g_array_index(global_capture_opts.ifaces, interface_options, j);
                if (j > 0) {
                    if (global_capture_opts.ifaces->len > 2) {
                        g_string_append_printf(str, ",");
                    }
                    g_string_append_printf(str, " ");
                    if (j == global_capture_opts.ifaces->len - 1) {
                        g_string_append_printf(str, "and ");
                    }
                }
                g_string_append_printf(str, "'%s'", interface_opts.console_display_name);
            }
        } else {
            g_string_append_printf(str, "%u interfaces", global_capture_opts.ifaces->len);
        }
        fprintf(stderr, "Capturing on %s\n", str->str);
        g_string_free(str, TRUE);
    }

    if (list_link_layer_types) {
        /* Get the list of link-layer types for the capture device. */
        if_capabilities_t *caps;
        gchar *err_str;
        guint  ii;

        for (ii = 0; ii < global_capture_opts.ifaces->len; ii++) {
            interface_options interface_opts;

            interface_opts = g_array_index(global_capture_opts.ifaces, interface_options, ii);
            caps = get_if_capabilities(interface_opts.name,
                                       interface_opts.monitor_mode, &err_str);
            if (caps == NULL) {
                cmdarg_err("The capabilities of the capture device \"%s\" could not be obtained (%s).\n"
                           "Please check to make sure you have sufficient permissions, and that\n"
                           "you have the proper interface or pipe specified.", interface_opts.name, err_str);
                g_free(err_str);
                exit_main(2);
            }
            if (caps->data_link_types == NULL) {
                cmdarg_err("The capture device \"%s\" has no data link types.", interface_opts.name);
                exit_main(2);
            }
            if (machine_readable)      /* tab-separated values to stdout */
                /* XXX: We need to change the format and adopt consumers */
                print_machine_readable_if_capabilities(caps);
            else
                /* XXX: We might want to print also the interface name */
                capture_opts_print_if_capabilities(caps, interface_opts.name,
                                                   interface_opts.monitor_mode);
            free_if_capabilities(caps);
        }
        exit_main(0);
    }

    /* We're supposed to do a capture, or print the BPF code for a filter.
       Process the snapshot length, as that affects the generated BPF code. */
    capture_opts_trim_snaplen(&global_capture_opts, MIN_PACKET_SIZE);

#ifdef HAVE_BPF_IMAGE
    if (print_bpf_code) {
        show_filter_code(&global_capture_opts);
        exit_main(0);
    }
#endif

    /* We're supposed to do a capture.  Process the ring buffer arguments. */
    capture_opts_trim_ring_num_files(&global_capture_opts);

    /* flush stderr prior to starting the main capture loop */
    fflush(stderr);

    /* Now start the capture. */

    if (capture_loop_start(&global_capture_opts, &stats_known, &stats) == TRUE) {
        /* capture ok */
        exit_main(0);
    } else {
        /* capture failed */
        exit_main(1);
    }
    return 0; /* never here, make compiler happy */
}


static void
console_log_handler(const char *log_domain, GLogLevelFlags log_level,
                    const char *message, gpointer user_data _U_)
{
    time_t      curr;
    struct tm  *today;
    const char *level;
    gchar      *msg;

    /* ignore log message, if log_level isn't interesting */
    if ( !(log_level & G_LOG_LEVEL_MASK & ~(G_LOG_LEVEL_DEBUG|G_LOG_LEVEL_INFO))) {
#if !defined(DEBUG_DUMPCAP) && !defined(DEBUG_CHILD_DUMPCAP)
        return;
#endif
    }

    /* create a "timestamp" */
    time(&curr);
    today = localtime(&curr);

    switch(log_level & G_LOG_LEVEL_MASK) {
    case G_LOG_LEVEL_ERROR:
        level = "Err ";
        break;
    case G_LOG_LEVEL_CRITICAL:
        level = "Crit";
        break;
    case G_LOG_LEVEL_WARNING:
        level = "Warn";
        break;
    case G_LOG_LEVEL_MESSAGE:
        level = "Msg ";
        break;
    case G_LOG_LEVEL_INFO:
        level = "Info";
        break;
    case G_LOG_LEVEL_DEBUG:
        level = "Dbg ";
        break;
    default:
        fprintf(stderr, "unknown log_level %u\n", log_level);
        level = NULL;
        g_assert_not_reached();
    }

    /* Generate the output message                                  */
    if (log_level & G_LOG_LEVEL_MESSAGE) {
        /* normal user messages without additional infos */
        msg =  g_strdup_printf("%s\n", message);
    } else {
        /* info/debug messages with additional infos */
        msg = g_strdup_printf("%02u:%02u:%02u %8s %s %s\n",
                              today->tm_hour, today->tm_min, today->tm_sec,
                              log_domain != NULL ? log_domain : "",
                              level, message);
    }

    /* DEBUG & INFO msgs (if we're debugging today)                 */
#if defined(DEBUG_DUMPCAP) || defined(DEBUG_CHILD_DUMPCAP)
    if ( !(log_level & G_LOG_LEVEL_MASK & ~(G_LOG_LEVEL_DEBUG|G_LOG_LEVEL_INFO))) {
#ifdef DEBUG_DUMPCAP
        fprintf(stderr, "%s", msg);
        fflush(stderr);
#endif
#ifdef DEBUG_CHILD_DUMPCAP
        fprintf(debug_log, "%s", msg);
        fflush(debug_log);
#endif
        g_free(msg);
        return;
    }
#endif

    /* ERROR, CRITICAL, WARNING, MESSAGE messages goto stderr or    */
    /*  to parent especially formatted if dumpcap running as child. */
    if (capture_child) {
        sync_pipe_errmsg_to_parent(2, msg, "");
    } else {
        fprintf(stderr, "%s", msg);
        fflush(stderr);
    }
    g_free(msg);
}


/****************************************************************************************************************/
/* indication report routines */


static void
report_packet_count(unsigned int packet_count)
{
    char tmp[SP_DECISIZE+1+1];
    static unsigned int count = 0;

    if (capture_child) {
        g_snprintf(tmp, sizeof(tmp), "%u", packet_count);
        g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "Packets: %s", tmp);
        pipe_write_block(2, SP_PACKET_COUNT, tmp);
    } else {
        count += packet_count;
        fprintf(stderr, "\rPackets: %u ", count);
        /* stderr could be line buffered */
        fflush(stderr);
    }
}

static void
report_new_capture_file(const char *filename)
{
    if (capture_child) {
        g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "File: %s", filename);
        pipe_write_block(2, SP_FILE, filename);
    } else {
#ifdef SIGINFO
        /*
         * Prevent a SIGINFO handler from writing to the standard error
         * while we're doing so; instead, have it just set a flag telling
         * us to print that information when we're done.
         */
        infodelay = TRUE;
#endif /* SIGINFO */
        fprintf(stderr, "File: %s\n", filename);
        /* stderr could be line buffered */
        fflush(stderr);

#ifdef SIGINFO
        /*
         * Allow SIGINFO handlers to write.
         */
        infodelay = FALSE;

        /*
         * If a SIGINFO handler asked us to write out capture counts, do so.
         */
        if (infoprint)
          report_counts_for_siginfo();
#endif /* SIGINFO */
    }
}

static void
report_cfilter_error(capture_options *capture_opts, guint i, const char *errmsg)
{
    interface_options interface_opts;
    char tmp[MSG_MAX_LENGTH+1+6];

    if (i < capture_opts->ifaces->len) {
        if (capture_child) {
            g_snprintf(tmp, sizeof(tmp), "%u:%s", i, errmsg);
            g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "Capture filter error: %s", errmsg);
            pipe_write_block(2, SP_BAD_FILTER, tmp);
        } else {
            /*
             * clopts_step_invalid_capfilter in test/suite-clopts.sh MUST match
             * the error message below.
             */
            interface_opts = g_array_index(capture_opts->ifaces, interface_options, i);
            cmdarg_err(
              "Invalid capture filter \"%s\" for interface '%s'!\n"
              "\n"
              "That string isn't a valid capture filter (%s).\n"
              "See the User's Guide for a description of the capture filter syntax.",
              interface_opts.cfilter, interface_opts.name, errmsg);
        }
    }
}

static void
report_capture_error(const char *error_msg, const char *secondary_error_msg)
{
    if (capture_child) {
        g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG,
            "Primary Error: %s", error_msg);
        g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG,
            "Secondary Error: %s", secondary_error_msg);
        sync_pipe_errmsg_to_parent(2, error_msg, secondary_error_msg);
    } else {
        cmdarg_err("%s", error_msg);
        if (secondary_error_msg[0] != '\0')
          cmdarg_err_cont("%s", secondary_error_msg);
    }
}

static void
report_packet_drops(guint32 received, guint32 pcap_drops, guint32 drops, guint32 flushed, guint32 ps_ifdrop, gchar *name)
{
    char tmp[SP_DECISIZE+1+1];
    guint32 total_drops = pcap_drops + drops + flushed;

    g_snprintf(tmp, sizeof(tmp), "%u", total_drops);

    if (capture_child) {
        g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG,
            "Packets received/dropped on interface '%s': %u/%u (pcap:%u/dumpcap:%u/flushed:%u/ps_ifdrop:%u)",
            name, received, total_drops, pcap_drops, drops, flushed, ps_ifdrop);
        /* XXX: Need to provide interface id, changes to consumers required. */
        pipe_write_block(2, SP_DROPS, tmp);
    } else {
        fprintf(stderr,
            "Packets received/dropped on interface '%s': %u/%u (pcap:%u/dumpcap:%u/flushed:%u/ps_ifdrop:%u) (%.1f%%)\n",
            name, received, total_drops, pcap_drops, drops, flushed, ps_ifdrop,
            received ? 100.0 * received / (received + total_drops) : 0.0);
        /* stderr could be line buffered */
        fflush(stderr);
    }
}


/************************************************************************************************/
/* signal_pipe handling */


#ifdef _WIN32
static gboolean
signal_pipe_check_running(void)
{
    /* any news from our parent? -> just stop the capture */
    DWORD    avail = 0;
    gboolean result;

    /* if we are running standalone, no check required */
    if (!capture_child) {
        return TRUE;
    }

    if (!sig_pipe_name || !sig_pipe_handle) {
        /* This shouldn't happen */
        g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO,
            "Signal pipe: No name or handle");
        return FALSE;
    }

    /*
     * XXX - We should have the process ID of the parent (from the "-Z" flag)
     * at this point.  Should we check to see if the parent is still alive,
     * e.g. by using OpenProcess?
     */

    result = PeekNamedPipe(sig_pipe_handle, NULL, 0, NULL, &avail, NULL);

    if (!result || avail > 0) {
        /* peek failed or some bytes really available */
        /* (if not piping from stdin this would fail) */
        g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO,
            "Signal pipe: Stop capture: %s", sig_pipe_name);
        g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG,
            "Signal pipe: %s (%p) result: %u avail: %u", sig_pipe_name,
            sig_pipe_handle, result, avail);
        return FALSE;
    } else {
        /* pipe ok and no bytes available */
        return TRUE;
    }
}
#endif





/*
 * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
 *
 * Local variables:
 * c-basic-offset: 4
 * tab-width: 8
 * indent-tabs-mode: nil
 * End:
 *
 * vi: set shiftwidth=4 tabstop=8 expandtab:
 * :indentSize=4:tabSize=8:noTabs=true:
 */