2 * Routines for packet capture windows
4 * $Id: capture.c,v 1.171 2002/02/24 09:25:34 guy Exp $
6 * Ethereal - Network traffic analyzer
7 * By Gerald Combs <gerald@ethereal.com>
8 * Copyright 1998 Gerald Combs
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version 2
13 * of the License, or (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
31 #ifdef HAVE_SYS_TYPES_H
32 # include <sys/types.h>
35 #ifdef HAVE_SYS_STAT_H
36 # include <sys/stat.h>
39 #ifdef HAVE_SYS_WAIT_H
40 # include <sys/wait.h>
45 * Define various POSIX macros (and, in the case of WCOREDUMP, non-POSIX
46 * macros) on UNIX systems that don't have them.
49 # define WIFEXITED(status) (((status) & 0177) == 0)
52 # define WIFSTOPPED(status) (((status) & 0177) == 0177)
55 # define WIFSIGNALED(status) (!WIFSTOPPED(status) && !WIFEXITED(status))
58 # define WEXITSTATUS(status) ((status) >> 8)
61 # define WTERMSIG(status) ((status) & 0177)
64 # define WCOREDUMP(status) ((status) & 0200)
67 # define WSTOPSIG(status) ((status) >> 8)
91 #ifdef HAVE_SYS_SOCKET_H
92 #include <sys/socket.h>
95 #ifdef HAVE_SYS_IOCTL_H
96 #include <sys/ioctl.h>
104 #ifdef NEED_SNPRINTF_H
105 # include "snprintf.h"
109 #include <process.h> /* For spawning child process */
113 * XXX - the various BSDs appear to define BSD in <sys/param.h>; we don't
114 * want to include it if it's not present on this platform, however.
116 #if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__bsdi__)
120 #endif /* defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__bsdi__) */
123 * We don't want to do a "select()" on the pcap_t's file descriptor on
124 * BSD (because "select()" doesn't work correctly on BPF devices on at
125 * least some releases of some flavors of BSD), and we don't want to do
126 * it on Windows (because "select()" is something for sockets, not for
127 * arbitrary handles).
129 * We *do* want to do it on other platforms, as, on other platforms (with
130 * the possible exception of Ultrix and Digital UNIX), the read timeout
131 * doesn't expire if no packets have arrived, so a "pcap_dispatch()" call
132 * will block until packets arrive, causing the UI to hang.
134 #if !defined(BSD) && !defined(_WIN32)
135 # define MUST_DO_SELECT
138 #include "gtk/main.h"
139 #include "gtk/gtkglobals.h"
140 #include <epan/packet.h>
144 #include "pcap-util.h"
145 #include "simple_dialog.h"
148 #include "conditions.h"
149 #include "capture_stop_conditions.h"
150 #include "ringbuffer.h"
152 #include "wiretap/libpcap.h"
153 #include "wiretap/wtap.h"
155 #include "packet-atalk.h"
156 #include "packet-clip.h"
157 #include "packet-eth.h"
158 #include "packet-fddi.h"
159 #include "packet-null.h"
160 #include "packet-ppp.h"
161 #include "packet-raw.h"
162 #include "packet-sll.h"
163 #include "packet-tr.h"
164 #include "packet-ieee80211.h"
165 #include "packet-chdlc.h"
166 #include "packet-prism.h"
169 #include "capture-wpcap.h"
175 capture_options capture_opts;
177 static int sync_pipe[2]; /* used to sync father */
178 enum PIPES { READ, WRITE }; /* Constants 0 and 1 for READ and WRITE */
179 int quit_after_cap; /* Makes a "capture only mode". Implies -k */
180 gboolean capture_child; /* if this is the child for "-S" */
181 static int fork_child = -1; /* If not -1, in parent, process ID of child */
182 static guint cap_input_id;
185 * Indications sent out on the sync pipe.
187 #define SP_CAPSTART ';' /* capture start message */
188 #define SP_PACKET_COUNT '*' /* followed by count of packets captured since last message */
189 #define SP_ERROR_MSG '!' /* followed by length of error message that follows */
190 #define SP_DROPS '#' /* followed by count of packets dropped in capture */
193 static guint cap_timer_id;
194 static int cap_timer_cb(gpointer); /* Win32 kludge to check for pipe input */
197 static void cap_file_input_cb(gpointer, gint, GdkInputCondition);
198 static void wait_for_child(gboolean);
200 static char *signame(int);
202 static void capture_delete_cb(GtkWidget *, GdkEvent *, gpointer);
203 static void capture_stop_cb(GtkWidget *, gpointer);
204 static void capture_pcap_cb(u_char *, const struct pcap_pkthdr *,
206 static void get_capture_file_io_error(char *, int, const char *, int, gboolean);
207 static void send_errmsg_to_parent(const char *);
208 static float pct(gint, gint);
209 static void stop_capture(int signo);
211 typedef struct _loop_data {
212 gboolean go; /* TRUE as long as we're supposed to keep capturing */
213 gint max; /* Number of packets we're supposed to capture - 0 means infinite */
214 int err; /* if non-zero, error seen while capturing */
217 gboolean pcap_err; /* TRUE if error from pcap */
218 gboolean from_pipe; /* TRUE if we are capturing data from a pipe */
219 gboolean modified; /* TRUE if data in the pipe uses modified pcap headers */
220 gboolean byte_swapped; /* TRUE if data in the pipe is byte swapped */
221 packet_counts counts;
226 static void adjust_header(loop_data *, struct pcap_hdr *, struct pcaprec_hdr *);
227 static int pipe_open_live(char *, struct pcap_hdr *, loop_data *, char *);
228 static int pipe_dispatch(int, loop_data *, struct pcap_hdr *);
231 /* Win32 needs the O_BINARY flag for open() */
237 /* Win32 needs a handle to the child capture process */
241 /* Add a string pointer to a NULL-terminated array of string pointers. */
243 add_arg(char **args, int *argc, char *arg)
245 /* Grow the array; "*argc" currently contains the number of string
246 pointers, *not* counting the NULL pointer at the end, so we have
247 to add 2 in order to get the new size of the array, including the
248 new pointer and the terminating NULL pointer. */
249 args = g_realloc(args, (*argc + 2) * sizeof (char *));
251 /* Stuff the pointer into the penultimate element of the array, which
252 is the one at the index specified by "*argc". */
255 /* Now bump the count. */
258 /* We overwrite the NULL pointer; put it back right after the
266 /* Given a string, return a pointer to a quote-encapsulated version of
267 the string, so we can pass it as an argument with "spawnvp" even
268 if it contains blanks. */
270 quote_encapsulate(const char *string)
272 char *encapsulated_string;
274 encapsulated_string = g_new(char, strlen(string) + 3);
275 sprintf(encapsulated_string, "\"%s\"", string);
276 return encapsulated_string;
280 /* Open a specified file, or create a temporary file, and start a capture
281 to the file in question. */
283 do_capture(char *capfile_name)
286 gboolean is_tempfile;
292 int capture_succeeded;
293 gboolean stats_known;
294 struct pcap_stat stats;
296 if (capfile_name != NULL) {
297 if (capture_opts.ringbuffer_on) {
298 /* ringbuffer is enabled */
299 cfile.save_file_fd = ringbuf_init(capfile_name,
300 capture_opts.ringbuffer_num_files);
302 /* Try to open/create the specified file for use as a capture buffer. */
303 cfile.save_file_fd = open(capfile_name, O_RDWR|O_BINARY|O_TRUNC|O_CREAT,
308 /* Choose a random name for the capture buffer */
309 cfile.save_file_fd = create_tempfile(tmpname, sizeof tmpname, "ether");
310 capfile_name = g_strdup(tmpname);
313 if (cfile.save_file_fd == -1) {
315 simple_dialog(ESD_TYPE_CRIT, NULL,
316 "The temporary file to which the capture would be saved (\"%s\")"
317 "could not be opened: %s.", capfile_name, strerror(errno));
319 if (capture_opts.ringbuffer_on) {
320 ringbuf_error_cleanup();
322 simple_dialog(ESD_TYPE_CRIT, NULL,
323 file_open_error_message(errno, TRUE), capfile_name);
327 close_cap_file(&cfile);
328 g_assert(cfile.save_file == NULL);
329 cfile.save_file = capfile_name;
331 if (capture_opts.sync_mode) { /* do the capture in a child process */
333 char scount[24]; /* need a constant for len of numbers */
334 char sautostop_filesize[24]; /* need a constant for len of numbers */
335 char sautostop_duration[24]; /* need a constant for len of numbers */
336 char save_file_fd[24];
342 char sync_pipe_fd[24];
347 /* Allocate the string pointer array with enough space for the
348 terminating NULL pointer. */
350 argv = g_malloc(sizeof (char *));
353 /* Now add those arguments used on all platforms. */
354 argv = add_arg(argv, &argc, CHILD_NAME);
356 argv = add_arg(argv, &argc, "-i");
357 argv = add_arg(argv, &argc, cfile.iface);
359 argv = add_arg(argv, &argc, "-w");
360 argv = add_arg(argv, &argc, cfile.save_file);
362 argv = add_arg(argv, &argc, "-W");
363 sprintf(save_file_fd,"%d",cfile.save_file_fd); /* in lieu of itoa */
364 argv = add_arg(argv, &argc, save_file_fd);
366 if (capture_opts.has_autostop_count) {
367 argv = add_arg(argv, &argc, "-c");
368 sprintf(scount,"%d",capture_opts.autostop_count);
369 argv = add_arg(argv, &argc, scount);
372 if (capture_opts.has_snaplen) {
373 argv = add_arg(argv, &argc, "-s");
374 sprintf(ssnap,"%d",capture_opts.snaplen);
375 argv = add_arg(argv, &argc, ssnap);
378 if (capture_opts.has_autostop_filesize) {
379 argv = add_arg(argv, &argc, "-a");
380 sprintf(sautostop_filesize,"filesize:%d",capture_opts.autostop_filesize);
381 argv = add_arg(argv, &argc, sautostop_filesize);
384 if (capture_opts.has_autostop_duration) {
385 argv = add_arg(argv, &argc, "-a");
386 sprintf(sautostop_duration,"duration:%d",capture_opts.autostop_duration);
387 argv = add_arg(argv, &argc, sautostop_duration);
390 if (!capture_opts.promisc_mode)
391 argv = add_arg(argv, &argc, "-p");
394 /* Create a pipe for the child process */
396 if(_pipe(sync_pipe, 512, O_BINARY) < 0) {
397 /* Couldn't create the pipe between parent and child. */
399 unlink(cfile.save_file);
400 g_free(cfile.save_file);
401 cfile.save_file = NULL;
402 simple_dialog(ESD_TYPE_CRIT, NULL, "Couldn't create sync pipe: %s",
407 /* Convert font name to a quote-encapsulated string and pass to child */
408 argv = add_arg(argv, &argc, "-m");
409 fontstring = quote_encapsulate(prefs.gui_font_name);
410 argv = add_arg(argv, &argc, fontstring);
412 /* Convert pipe write handle to a string and pass to child */
413 argv = add_arg(argv, &argc, "-Z");
414 itoa(sync_pipe[WRITE], sync_pipe_fd, 10);
415 argv = add_arg(argv, &argc, sync_pipe_fd);
417 /* Convert filter string to a quote delimited string and pass to child */
418 if (cfile.cfilter != NULL && strlen(cfile.cfilter) != 0) {
419 argv = add_arg(argv, &argc, "-f");
420 filterstring = quote_encapsulate(cfile.cfilter);
421 argv = add_arg(argv, &argc, filterstring);
425 fork_child = spawnvp(_P_NOWAIT, ethereal_path, argv);
427 g_free(filterstring);
428 /* Keep a copy for later evaluation by _cwait() */
429 child_process = fork_child;
431 signal(SIGCHLD, SIG_IGN);
432 if (pipe(sync_pipe) < 0) {
433 /* Couldn't create the pipe between parent and child. */
435 unlink(cfile.save_file);
436 g_free(cfile.save_file);
437 cfile.save_file = NULL;
438 simple_dialog(ESD_TYPE_CRIT, NULL, "Couldn't create sync pipe: %s",
443 argv = add_arg(argv, &argc, "-m");
444 argv = add_arg(argv, &argc, prefs.gui_font_name);
446 if (cfile.cfilter != NULL && strlen(cfile.cfilter) != 0) {
447 argv = add_arg(argv, &argc, "-f");
448 argv = add_arg(argv, &argc, cfile.cfilter);
451 if ((fork_child = fork()) == 0) {
453 * Child process - run Ethereal with the right arguments to make
454 * it just pop up the live capture dialog box and capture with
455 * the specified capture parameters, writing to the specified file.
457 * args: -i interface specification
459 * -W file descriptor to write
460 * -c count to capture
463 * -f "filter expression"
466 dup(sync_pipe[WRITE]);
467 close(sync_pipe[READ]);
468 execvp(ethereal_path, argv);
469 snprintf(errmsg, sizeof errmsg, "Couldn't run %s in child process: %s",
470 ethereal_path, strerror(errno));
471 send_errmsg_to_parent(errmsg);
473 /* Exit with "_exit()", so that we don't close the connection
474 to the X server (and cause stuff buffered up by our parent but
475 not yet sent to be sent, as that stuff should only be sent by
481 /* Parent process - read messages from the child process over the
483 g_free(argv); /* free up arg array */
485 /* Close the write side of the pipe, so that only the child has it
486 open, and thus it completely closes, and thus returns to us
487 an EOF indication, if the child closes it (either deliberately
488 or by exiting abnormally). */
489 close(sync_pipe[WRITE]);
491 /* Close the save file FD, as we won't be using it - we'll be opening
492 it and reading the save file through Wiretap. */
493 close(cfile.save_file_fd);
495 if (fork_child == -1) {
496 /* We couldn't even create the child process. */
498 close(sync_pipe[READ]);
499 unlink(cfile.save_file);
500 g_free(cfile.save_file);
501 cfile.save_file = NULL;
502 simple_dialog(ESD_TYPE_CRIT, NULL, "Couldn't create child process: %s",
507 /* Read a byte count from "sync_pipe[READ]", terminated with a
508 colon; if the count is 0, the child process created the
509 capture file and we should start reading from it, otherwise
510 the capture couldn't start and the count is a count of bytes
511 of error message, and we should display the message. */
514 i = read(sync_pipe[READ], &c, 1);
516 /* EOF - the child process died.
517 Close the read side of the sync pipe, remove the capture file,
518 and report the failure. */
519 close(sync_pipe[READ]);
520 unlink(cfile.save_file);
521 g_free(cfile.save_file);
522 cfile.save_file = NULL;
523 wait_for_child(TRUE);
526 if (c == SP_CAPSTART || c == SP_ERROR_MSG)
529 /* Child process handed us crap.
530 Close the read side of the sync pipe, remove the capture file,
531 and report the failure. */
532 close(sync_pipe[READ]);
533 unlink(cfile.save_file);
534 g_free(cfile.save_file);
535 cfile.save_file = NULL;
536 simple_dialog(ESD_TYPE_WARN, NULL,
537 "Capture child process sent us a bad message");
540 byte_count = byte_count*10 + c - '0';
542 if (c == SP_CAPSTART) {
543 /* Success. Open the capture file, and set up to read it. */
544 err = start_tail_cap_file(cfile.save_file, is_tempfile, &cfile);
546 /* We were able to open and set up to read the capture file;
547 arrange that our callback be called whenever it's possible
548 to read from the sync pipe, so that it's called when
549 the child process wants to tell us something. */
551 /* Tricky to use pipes in win9x, as no concept of wait. NT can
552 do this but that doesn't cover all win32 platforms. GTK can do
553 this but doesn't seem to work over processes. Attempt to do
554 something similar here, start a timer and check for data on every
556 cap_timer_id = gtk_timeout_add(1000, cap_timer_cb, NULL);
558 cap_input_id = gtk_input_add_full(sync_pipe[READ],
559 GDK_INPUT_READ|GDK_INPUT_EXCEPTION,
566 /* We weren't able to open the capture file; complain, and
567 close the sync pipe. */
568 simple_dialog(ESD_TYPE_CRIT, NULL,
569 file_open_error_message(err, FALSE), cfile.save_file);
571 /* Close the sync pipe. */
572 close(sync_pipe[READ]);
574 /* Don't unlink the save file - leave it around, for debugging
576 g_free(cfile.save_file);
577 cfile.save_file = NULL;
580 /* Failure - the child process sent us a message indicating
581 what the problem was. */
582 if (byte_count == 0) {
583 /* Zero-length message? */
584 simple_dialog(ESD_TYPE_WARN, NULL,
585 "Capture child process failed, but its error message was empty.");
587 msg = g_malloc(byte_count + 1);
589 simple_dialog(ESD_TYPE_WARN, NULL,
590 "Capture child process failed, but its error message was too big.");
592 i = read(sync_pipe[READ], msg, byte_count);
593 msg[byte_count] = '\0';
595 simple_dialog(ESD_TYPE_WARN, NULL,
596 "Capture child process failed: Error %s reading its error message.",
599 simple_dialog(ESD_TYPE_WARN, NULL,
600 "Capture child process failed: EOF reading its error message.");
601 wait_for_child(FALSE);
603 simple_dialog(ESD_TYPE_WARN, NULL, msg);
607 /* Close the sync pipe. */
608 close(sync_pipe[READ]);
610 /* Get rid of the save file - the capture never started. */
611 unlink(cfile.save_file);
612 g_free(cfile.save_file);
613 cfile.save_file = NULL;
618 capture_succeeded = capture(&stats_known, &stats);
619 if (quit_after_cap) {
620 /* DON'T unlink the save file. Presumably someone wants it. */
623 if (capture_succeeded) {
624 /* Capture succeeded; read in the capture file. */
625 if ((err = open_cap_file(cfile.save_file, is_tempfile, &cfile)) == 0) {
626 /* Set the read filter to NULL. */
629 /* Get the packet-drop statistics.
631 XXX - there are currently no packet-drop statistics stored
632 in libpcap captures, and that's what we're reading.
634 At some point, we will add support in Wiretap to return
635 packet-drop statistics for capture file formats that store it,
636 and will make "read_cap_file()" get those statistics from
637 Wiretap. We clear the statistics (marking them as "not known")
638 in "open_cap_file()", and "read_cap_file()" will only fetch
639 them and mark them as known if Wiretap supplies them, so if
640 we get the statistics now, after calling "open_cap_file()" but
641 before calling "read_cap_file()", the values we store will
642 be used by "read_cap_file()".
644 If a future libpcap capture file format stores the statistics,
645 we'll put them into the capture file that we write, and will
646 thus not have to set them here - "read_cap_file()" will get
647 them from the file and use them. */
649 cfile.drops_known = TRUE;
651 /* XXX - on some systems, libpcap doesn't bother filling in
652 "ps_ifdrop" - it doesn't even set it to zero - so we don't
653 bother looking at it.
655 Ideally, libpcap would have an interface that gave us
656 several statistics - perhaps including various interface
657 error statistics - and would tell us which of them it
658 supplies, allowing us to display only the ones it does. */
659 cfile.drops = stats.ps_drop;
661 switch (read_cap_file(&cfile, &err)) {
665 /* Just because we got an error, that doesn't mean we were unable
666 to read any of the file; we handle what we could get from the
671 /* Exit by leaving the main loop, so that any quit functions
672 we registered get called. */
678 /* We're not doing a capture any more, so we don't have a save
680 if (capture_opts.ringbuffer_on) {
683 g_free(cfile.save_file);
685 cfile.save_file = NULL;
690 /* The timer has expired, see if there's stuff to read from the pipe,
691 if so call the cap_file_input_cb */
693 cap_timer_cb(gpointer data)
697 gboolean result, result1;
700 /* Oddly enough although Named pipes don't work on win9x,
701 PeekNamedPipe does !!! */
702 handle = (HANDLE) _get_osfhandle (sync_pipe[READ]);
703 result = PeekNamedPipe(handle, NULL, 0, NULL, &avail, NULL);
705 /* Get the child process exit status */
706 result1 = GetExitCodeProcess((HANDLE)child_process, &childstatus);
708 /* If the Peek returned an error, or there are bytes to be read
709 or the childwatcher thread has terminated then call the normal
711 if (!result || avail > 0 || childstatus != STILL_ACTIVE) {
713 /* avoid reentrancy problems and stack overflow */
714 gtk_timeout_remove(cap_timer_id);
716 /* And call the real handler */
717 cap_file_input_cb((gpointer) &cfile, 0, 0);
719 /* Return false so that the timer is not run again */
723 /* No data so let timer run again */
729 /* There's stuff to read from the sync pipe, meaning the child has sent
730 us a message, or the sync pipe has closed, meaning the child has
731 closed it (perhaps because it exited). */
733 cap_file_input_cb(gpointer data, gint source, GdkInputCondition condition)
735 capture_file *cf = (capture_file *)data;
737 char buffer[BUFSIZE+1], *p = buffer, *q = buffer, *msg, *r;
738 int nread, msglen, chars_to_copy;
743 /* avoid reentrancy problems and stack overflow */
744 gtk_input_remove(cap_input_id);
747 if ((nread = read(sync_pipe[READ], buffer, BUFSIZE)) <= 0) {
748 /* The child has closed the sync pipe, meaning it's not going to be
749 capturing any more packets. Pick up its exit status, and
750 complain if it did anything other than exit with status 0. */
751 wait_for_child(FALSE);
753 /* Read what remains of the capture file, and finish the capture.
754 XXX - do something if this fails? */
755 switch (finish_tail_cap_file(cf, &err)) {
759 /* Just because we got an error, that doesn't mean we were unable
760 to read any of the file; we handle what we could get from the
765 /* Exit by leaving the main loop, so that any quit functions
766 we registered get called. */
771 /* We're not doing a capture any more, so we don't have a save
773 g_free(cf->save_file);
774 cf->save_file = NULL;
779 buffer[nread] = '\0';
782 /* look for (possibly multiple) indications */
784 case SP_PACKET_COUNT :
791 cf->drops_known = TRUE;
803 /* Read the entire message.
804 XXX - if the child hasn't sent it all yet, this could cause us
805 to hang until they do. */
806 msg = g_malloc(msglen + 1);
808 while (msglen != 0) {
811 if ((nread = read(sync_pipe[READ], buffer, BUFSIZE)) <= 0)
816 chars_to_copy = MIN(msglen, nread);
817 memcpy(r, q, chars_to_copy);
820 nread -= chars_to_copy;
821 msglen -= chars_to_copy;
824 simple_dialog(ESD_TYPE_WARN, NULL, msg);
834 /* Read from the capture file the number of records the child told us
836 XXX - do something if this fails? */
837 switch (continue_tail_cap_file(cf, to_read, &err)) {
841 /* Just because we got an error, that doesn't mean we were unable
842 to read any of the file; we handle what we could get from the
845 XXX - abort on a read error? */
849 /* Kill the child capture process; the user wants to exit, and we
850 shouldn't just leave it running. */
854 kill(fork_child, SIGTERM); /* SIGTERM so it can clean up if necessary */
859 /* restore pipe handler */
861 cap_timer_id = gtk_timeout_add(1000, cap_timer_cb, NULL);
863 cap_input_id = gtk_input_add_full (sync_pipe[READ],
864 GDK_INPUT_READ|GDK_INPUT_EXCEPTION,
873 wait_for_child(gboolean always_report)
878 /* XXX - analyze the wait stuatus and display more information
879 in the dialog box? */
880 if (_cwait(&wstatus, child_process, _WAIT_CHILD) == -1) {
881 simple_dialog(ESD_TYPE_WARN, NULL, "Child capture process stopped unexpectedly");
884 if (wait(&wstatus) != -1) {
885 if (WIFEXITED(wstatus)) {
886 /* The child exited; display its exit status, if it's not zero,
887 and even if it's zero if "always_report" is true. */
888 if (always_report || WEXITSTATUS(wstatus) != 0) {
889 simple_dialog(ESD_TYPE_WARN, NULL,
890 "Child capture process exited: exit status %d",
891 WEXITSTATUS(wstatus));
893 } else if (WIFSTOPPED(wstatus)) {
894 /* It stopped, rather than exiting. "Should not happen." */
895 simple_dialog(ESD_TYPE_WARN, NULL,
896 "Child capture process stopped: %s",
897 signame(WSTOPSIG(wstatus)));
898 } else if (WIFSIGNALED(wstatus)) {
899 /* It died with a signal. */
900 simple_dialog(ESD_TYPE_WARN, NULL,
901 "Child capture process died: %s%s",
902 signame(WTERMSIG(wstatus)),
903 WCOREDUMP(wstatus) ? " - core dumped" : "");
905 /* What? It had to either have exited, or stopped, or died with
906 a signal; what happened here? */
907 simple_dialog(ESD_TYPE_WARN, NULL,
908 "Child capture process died: wait status %#o", wstatus);
912 /* No more child process. */
922 static char sigmsg_buf[6+1+3+1];
931 sigmsg = "Interrupted";
939 sigmsg = "Illegal instruction";
943 sigmsg = "Trace trap";
951 sigmsg = "Arithmetic exception";
959 sigmsg = "Bus error";
963 sigmsg = "Segmentation violation";
966 /* http://metalab.unc.edu/pub/Linux/docs/HOWTO/GCC-HOWTO
967 Linux is POSIX compliant. These are not POSIX-defined signals ---
968 ISO/IEC 9945-1:1990 (IEEE Std 1003.1-1990), paragraph B.3.3.1.1 sez:
970 ``The signals SIGBUS, SIGEMT, SIGIOT, SIGTRAP, and SIGSYS
971 were omitted from POSIX.1 because their behavior is
972 implementation dependent and could not be adequately catego-
973 rized. Conforming implementations may deliver these sig-
974 nals, but must document the circumstances under which they
975 are delivered and note any restrictions concerning their
978 So we only check for SIGSYS on those systems that happen to
979 implement them (a system can be POSIX-compliant and implement
980 them, it's just that POSIX doesn't *require* a POSIX-compliant
981 system to implement them).
986 sigmsg = "Bad system call";
991 sigmsg = "Broken pipe";
995 sigmsg = "Alarm clock";
999 sigmsg = "Terminated";
1003 sprintf(sigmsg_buf, "Signal %d", sig);
1004 sigmsg = sigmsg_buf;
1012 * Timeout, in milliseconds, for reads from the stream of captured packets.
1014 * XXX - Michael Tuexen says MacOS X's BPF appears to be broken, in that
1015 * if you use a timeout of 250 in "pcap_open_live()", you don't see
1016 * packets until a large number of packets arrive; the timeout doesn't
1017 * cause a smaller number of packets to be delivered. Perhaps a timeout
1018 * that's less than 1 second acts like no timeout at all, so that you
1019 * don't see packets until the BPF buffer fills up?
1021 * The workaround is to use a timeout of 1000 seconds on MacOS X.
1024 #define CAP_READ_TIMEOUT 1000
1026 #define CAP_READ_TIMEOUT 250
1030 /* Take carre of byte order in the libpcap headers read from pipes.
1031 * (function taken from wiretap/libpcap.c) */
1033 adjust_header(loop_data *ld, struct pcap_hdr *hdr, struct pcaprec_hdr *rechdr)
1035 if (ld->byte_swapped) {
1036 /* Byte-swap the record header fields. */
1037 rechdr->ts_sec = BSWAP32(rechdr->ts_sec);
1038 rechdr->ts_usec = BSWAP32(rechdr->ts_usec);
1039 rechdr->incl_len = BSWAP32(rechdr->incl_len);
1040 rechdr->orig_len = BSWAP32(rechdr->orig_len);
1043 /* In file format version 2.3, the "incl_len" and "orig_len" fields were
1044 swapped, in order to match the BPF header layout.
1046 Unfortunately, some files were, according to a comment in the "libpcap"
1047 source, written with version 2.3 in their headers but without the
1048 interchanged fields, so if "incl_len" is greater than "orig_len" - which
1049 would make no sense - we assume that we need to swap them. */
1050 if (hdr->version_major == 2 &&
1051 (hdr->version_minor < 3 ||
1052 (hdr->version_minor == 3 && rechdr->incl_len > rechdr->orig_len))) {
1055 temp = rechdr->orig_len;
1056 rechdr->orig_len = rechdr->incl_len;
1057 rechdr->incl_len = temp;
1061 /* Mimic pcap_open_live() for pipe captures
1062 * We check if "pipename" is "-" (stdin) or a FIFO, open it, and read the
1064 * N.B. : we can't read the libpcap formats used in RedHat 6.1 or SuSE 6.3
1065 * because we can't seek on pipes (see wiretap/libpcap.c for details) */
1067 pipe_open_live(char *pipename, struct pcap_hdr *hdr, loop_data *ld, char *ebuf)
1069 struct stat pipe_stat;
1074 if (strcmp(pipename, "-") == 0) fd = 0; /* read from stdin */
1075 else if (stat(pipename, &pipe_stat) == 0 && S_ISFIFO(pipe_stat.st_mode)) {
1076 if ((fd = open(pipename, O_RDONLY)) == -1) return -1;
1079 ld->from_pipe = TRUE;
1080 /* read the pcap header */
1081 if (read(fd, &magic, sizeof magic) != sizeof magic) {
1088 /* Host that wrote it has our byte order, and was running
1089 a program using either standard or ss990417 libpcap. */
1090 ld->byte_swapped = FALSE;
1091 ld->modified = FALSE;
1093 case PCAP_MODIFIED_MAGIC:
1094 /* Host that wrote it has our byte order, but was running
1095 a program using either ss990915 or ss991029 libpcap. */
1096 ld->byte_swapped = FALSE;
1097 ld->modified = TRUE;
1099 case PCAP_SWAPPED_MAGIC:
1100 /* Host that wrote it has a byte order opposite to ours,
1101 and was running a program using either standard or
1102 ss990417 libpcap. */
1103 ld->byte_swapped = TRUE;
1104 ld->modified = FALSE;
1106 case PCAP_SWAPPED_MODIFIED_MAGIC:
1107 /* Host that wrote it out has a byte order opposite to
1108 ours, and was running a program using either ss990915
1109 or ss991029 libpcap. */
1110 ld->byte_swapped = TRUE;
1111 ld->modified = TRUE;
1114 /* Not a "libpcap" type we know about. */
1119 /* Read the rest of the header */
1120 bytes_read = read(fd, hdr, sizeof(struct pcap_hdr));
1121 if (bytes_read <= 0) {
1125 while ((unsigned) bytes_read < sizeof(struct pcap_hdr))
1127 b = read(fd, ((char *)&hdr)+bytes_read, sizeof(struct pcap_hdr) - bytes_read);
1134 if (ld->byte_swapped) {
1135 /* Byte-swap the header fields about which we care. */
1136 hdr->version_major = BSWAP16(hdr->version_major);
1137 hdr->version_minor = BSWAP16(hdr->version_minor);
1138 hdr->snaplen = BSWAP32(hdr->snaplen);
1139 hdr->network = BSWAP32(hdr->network);
1141 if (hdr->version_major < 2) {
1149 /* We read one record from the pipe, take care of byte order in the record
1150 * header, write the record in the capture file, and update capture statistics. */
1152 pipe_dispatch(int fd, loop_data *ld, struct pcap_hdr *hdr)
1154 struct wtap_pkthdr whdr;
1155 struct pcaprec_modified_hdr rechdr;
1156 int bytes_to_read, bytes_read, b;
1157 u_char pd[WTAP_MAX_PACKET_SIZE];
1160 /* read the record header */
1161 bytes_to_read = ld->modified ? sizeof rechdr : sizeof rechdr.hdr;
1162 bytes_read = read(fd, &rechdr, bytes_to_read);
1163 if (bytes_read <= 0) {
1168 while (bytes_read < bytes_to_read)
1170 b = read(fd, ((char *)&rechdr)+bytes_read, bytes_to_read - bytes_read);
1178 /* take care of byte order */
1179 adjust_header(ld, hdr, &rechdr.hdr);
1180 if (rechdr.hdr.incl_len > WTAP_MAX_PACKET_SIZE) {
1185 /* read the packet data */
1186 bytes_read = read(fd, pd, rechdr.hdr.incl_len);
1187 if (bytes_read <= 0) {
1192 while ((unsigned) bytes_read < rechdr.hdr.incl_len)
1194 b = read(fd, pd+bytes_read, rechdr.hdr.incl_len - bytes_read);
1202 /* dump the packet data to the capture file */
1203 whdr.ts.tv_sec = rechdr.hdr.ts_sec;
1204 whdr.ts.tv_usec = rechdr.hdr.ts_usec;
1205 whdr.caplen = rechdr.hdr.incl_len;
1206 whdr.len = rechdr.hdr.orig_len;
1207 whdr.pkt_encap = ld->linktype;
1208 wtap_dump(ld->pdh, &whdr, NULL, pd, &err);
1210 /* update capture statistics */
1211 switch (ld->linktype) {
1212 case WTAP_ENCAP_ETHERNET:
1213 capture_eth(pd, 0, whdr.caplen, &ld->counts);
1215 case WTAP_ENCAP_FDDI:
1216 case WTAP_ENCAP_FDDI_BITSWAPPED:
1217 capture_fddi(pd, whdr.caplen, &ld->counts);
1219 case WTAP_ENCAP_PRISM_HEADER:
1220 capture_prism(pd, 0, whdr.caplen, &ld->counts);
1222 case WTAP_ENCAP_TOKEN_RING:
1223 capture_tr(pd, 0, whdr.caplen, &ld->counts);
1225 case WTAP_ENCAP_NULL:
1226 capture_null(pd, whdr.caplen, &ld->counts);
1228 case WTAP_ENCAP_PPP:
1229 capture_ppp_hdlc(pd, 0, whdr.caplen, &ld->counts);
1231 case WTAP_ENCAP_RAW_IP:
1232 capture_raw(pd, whdr.caplen, &ld->counts);
1234 case WTAP_ENCAP_LINUX_ATM_CLIP:
1235 capture_clip(pd, whdr.caplen, &ld->counts);
1237 case WTAP_ENCAP_IEEE_802_11:
1238 capture_ieee80211(pd, 0, whdr.caplen, &ld->counts);
1240 case WTAP_ENCAP_CHDLC:
1241 capture_chdlc(pd, 0, whdr.caplen, &ld->counts);
1243 case WTAP_ENCAP_LOCALTALK:
1244 capture_llap(pd, whdr.caplen, &ld->counts);
1246 /* XXX - FreeBSD may append 4-byte ATM pseudo-header to DLT_ATM_RFC1483,
1247 with LLC header following; we should implement it at some
1256 * This needs to be static, so that the SIGUSR1 handler can clear the "go"
1259 static loop_data ld;
1261 /* Do the low-level work of a capture.
1262 Returns TRUE if it succeeds, FALSE otherwise. */
1264 capture(gboolean *stats_known, struct pcap_stat *stats)
1266 GtkWidget *cap_w, *main_vb, *stop_bt, *counts_tb;
1270 gchar open_err_str[PCAP_ERRBUF_SIZE];
1271 gchar lookup_net_err_str[PCAP_ERRBUF_SIZE];
1272 gchar label_str[64];
1273 bpf_u_int32 netnum, netmask;
1274 struct bpf_program fcode;
1275 time_t upd_time, cur_time;
1277 condition *cnd_stop_capturesize = NULL;
1278 condition *cnd_stop_timeout = NULL;
1280 static const char capstart_msg = SP_CAPSTART;
1281 char errmsg[4096+1];
1284 static const char ppamsg[] = "can't find PPA for ";
1288 struct timeval timeout;
1289 #ifdef MUST_DO_SELECT
1293 WORD wVersionRequested;
1298 struct pcap_hdr hdr;
1303 GtkWidget *label, *value, *percent;
1305 { "Total", &ld.counts.total, NULL, NULL, NULL },
1306 { "SCTP", &ld.counts.sctp, NULL, NULL, NULL },
1307 { "TCP", &ld.counts.tcp, NULL, NULL, NULL },
1308 { "UDP", &ld.counts.udp, NULL, NULL, NULL },
1309 { "ICMP", &ld.counts.icmp, NULL, NULL, NULL },
1310 { "OSPF", &ld.counts.ospf, NULL, NULL, NULL },
1311 { "GRE", &ld.counts.gre, NULL, NULL, NULL },
1312 { "NetBIOS", &ld.counts.netbios, NULL, NULL, NULL },
1313 { "IPX", &ld.counts.ipx, NULL, NULL, NULL },
1314 { "VINES", &ld.counts.vines, NULL, NULL, NULL },
1315 { "Other", &ld.counts.other, NULL, NULL, NULL }
1318 #define N_COUNTS (sizeof counts / sizeof counts[0])
1320 /* Initialize Windows Socket if we are in a WIN32 OS
1321 This needs to be done before querying the interface for network/netmask */
1323 wVersionRequested = MAKEWORD( 1, 1 );
1324 err = WSAStartup( wVersionRequested, &wsaData );
1326 snprintf(errmsg, sizeof errmsg,
1327 "Couldn't initialize Windows Sockets.");
1334 ld.counts.total = 0;
1335 if (capture_opts.has_autostop_count)
1336 ld.max = capture_opts.autostop_count;
1338 ld.max = 0; /* no limit */
1339 ld.err = 0; /* no error seen yet */
1340 ld.linktype = WTAP_ENCAP_UNKNOWN;
1341 ld.pcap_err = FALSE;
1342 ld.from_pipe = FALSE;
1343 ld.sync_packets = 0;
1351 ld.counts.netbios = 0;
1352 ld.counts.vines = 0;
1353 ld.counts.other = 0;
1356 /* We haven't yet gotten the capture statistics. */
1357 *stats_known = FALSE;
1359 /* Open the network interface to capture from it.
1360 Some versions of libpcap may put warnings into the error buffer
1361 if they succeed; to tell if that's happened, we have to clear
1362 the error buffer, and check if it's still a null string. */
1363 open_err_str[0] = '\0';
1364 pch = pcap_open_live(cfile.iface,
1365 capture_opts.has_snaplen ? capture_opts.snaplen :
1366 WTAP_MAX_PACKET_SIZE,
1367 capture_opts.promisc_mode, CAP_READ_TIMEOUT,
1372 /* Well, we couldn't start the capture.
1373 If this is a child process that does the capturing in sync
1374 mode or fork mode, it shouldn't do any UI stuff until we pop up the
1375 capture-progress window, and, since we couldn't start the
1376 capture, we haven't popped it up. */
1377 if (!capture_child) {
1378 while (gtk_events_pending()) gtk_main_iteration();
1381 /* On Win32 OSes, the capture devices are probably available to all
1382 users; don't warn about permissions problems.
1384 Do, however, warn that WAN devices aren't supported. */
1385 snprintf(errmsg, sizeof errmsg,
1386 "The capture session could not be initiated (%s).\n"
1387 "Please check that you have the proper interface specified.\n"
1389 "Note that the driver Ethereal uses for packet capture on Windows\n"
1390 "doesn't support capturing on PPP/WAN interfaces in Windows NT/2000.\n",
1394 /* try to open cfile.iface as a pipe */
1395 pipe_fd = pipe_open_live(cfile.iface, &hdr, &ld, open_err_str);
1397 if (pipe_fd == -1) {
1398 /* Well, we couldn't start the capture.
1399 If this is a child process that does the capturing in sync
1400 mode or fork mode, it shouldn't do any UI stuff until we pop up the
1401 capture-progress window, and, since we couldn't start the
1402 capture, we haven't popped it up. */
1403 if (!capture_child) {
1404 while (gtk_events_pending()) gtk_main_iteration();
1407 /* If we got a "can't find PPA for XXX" message, warn the user (who
1408 is running Ethereal on HP-UX) that they don't have a version
1409 of libpcap that properly handles HP-UX (libpcap 0.6.x and later
1410 versions, which properly handle HP-UX, say "can't find /dev/dlpi
1411 PPA for XXX" rather than "can't find PPA for XXX"). */
1412 if (strncmp(open_err_str, ppamsg, sizeof ppamsg - 1) == 0)
1415 "You are running Ethereal with a version of the libpcap library\n"
1416 "that doesn't handle HP-UX network devices well; this means that\n"
1417 "Ethereal may not be able to capture packets.\n"
1419 "To fix this, you should install libpcap 0.6.2, or a later version\n"
1420 "of libpcap, rather than libpcap 0.4 or 0.5.x. It is available in\n"
1421 "packaged binary form from the Software Porting And Archive Centre\n"
1422 "for HP-UX; the Centre is at http://hpux.connect.org.uk/ - the page\n"
1423 "at the URL lists a number of mirror sites.";
1426 snprintf(errmsg, sizeof errmsg,
1427 "The capture session could not be initiated (%s).\n"
1428 "Please check to make sure you have sufficient permissions, and that\n"
1429 "you have the proper interface or pipe specified.%s", open_err_str,
1436 /* capture filters only work on real interfaces */
1437 if (cfile.cfilter && !ld.from_pipe) {
1438 /* A capture filter was specified; set it up. */
1439 if (pcap_lookupnet(cfile.iface, &netnum, &netmask, lookup_net_err_str) < 0) {
1441 * Well, we can't get the netmask for this interface; it's used
1442 * only for filters that check for broadcast IP addresses, so
1443 * we just punt and use 0. It might be nice to warn the user,
1444 * but that's a pain in a GUI application, as it'd involve popping
1445 * up a message box, and it's not clear how often this would make
1446 * a difference (only filters that check for IP broadcast addresses
1451 if (pcap_compile(pch, &fcode, cfile.cfilter, 1, netmask) < 0) {
1452 snprintf(errmsg, sizeof errmsg, "Unable to parse filter string (%s).",
1456 if (pcap_setfilter(pch, &fcode) < 0) {
1457 snprintf(errmsg, sizeof errmsg, "Can't install filter (%s).",
1463 /* Set up to write to the capture file. */
1466 pcap_encap = hdr.network;
1467 file_snaplen = hdr.snaplen;
1471 pcap_encap = get_pcap_linktype(pch, cfile.iface);
1472 file_snaplen = pcap_snapshot(pch);
1474 ld.linktype = wtap_pcap_encap_to_wtap_encap(pcap_encap);
1475 if (ld.linktype == WTAP_ENCAP_UNKNOWN) {
1476 snprintf(errmsg, sizeof errmsg,
1477 "The network you're capturing from is of a type"
1478 " that Ethereal doesn't support (data link type %d).", pcap_encap);
1481 if (capture_opts.ringbuffer_on) {
1482 ld.pdh = ringbuf_init_wtap_dump_fdopen(WTAP_FILE_PCAP, ld.linktype,
1483 file_snaplen, &err);
1485 ld.pdh = wtap_dump_fdopen(cfile.save_file_fd, WTAP_FILE_PCAP,
1486 ld.linktype, file_snaplen, &err);
1489 if (ld.pdh == NULL) {
1490 /* We couldn't set up to write to the capture file. */
1493 case WTAP_ERR_CANT_OPEN:
1494 strcpy(errmsg, "The file to which the capture would be saved"
1495 " couldn't be created for some unknown reason.");
1498 case WTAP_ERR_SHORT_WRITE:
1499 strcpy(errmsg, "A full header couldn't be written to the file"
1500 " to which the capture would be saved.");
1505 snprintf(errmsg, sizeof(errmsg),
1506 "The file to which the capture would be"
1507 " saved (\"%s\") could not be opened: Error %d.",
1508 cfile.save_file, err);
1510 snprintf(errmsg, sizeof(errmsg),
1511 "The file to which the capture would be"
1512 " saved (\"%s\") could not be opened: %s.",
1513 cfile.save_file, strerror(err));
1520 /* Does "open_err_str" contain a non-empty string? If so, "pcap_open_live()"
1521 returned a warning; print it, but keep capturing. */
1522 if (open_err_str[0] != '\0')
1523 g_warning("%s.", open_err_str);
1525 /* XXX - capture SIGTERM and close the capture, in case we're on a
1526 Linux 2.0[.x] system and you have to explicitly close the capture
1527 stream in order to turn promiscuous mode off? We need to do that
1528 in other places as well - and I don't think that works all the
1529 time in any case, due to libpcap bugs. */
1531 if (capture_child) {
1532 /* Well, we should be able to start capturing.
1534 This is the child process for a sync mode capture, so sync out
1535 the capture file, so the header makes it to the file system,
1536 and send a "capture started successfully and capture file created"
1537 message to our parent so that they'll open the capture file and
1538 update its windows to indicate that we have a live capture in
1540 fflush(wtap_dump_file(ld.pdh));
1541 write(1, &capstart_msg, 1);
1544 cap_w = gtk_window_new(GTK_WINDOW_TOPLEVEL);
1545 gtk_window_set_title(GTK_WINDOW(cap_w), "Ethereal: Capture");
1546 gtk_window_set_modal(GTK_WINDOW(cap_w), TRUE);
1548 /* Container for capture display widgets */
1549 main_vb = gtk_vbox_new(FALSE, 1);
1550 gtk_container_border_width(GTK_CONTAINER(main_vb), 5);
1551 gtk_container_add(GTK_CONTAINER(cap_w), main_vb);
1552 gtk_widget_show(main_vb);
1554 /* Individual statistic elements */
1555 counts_tb = gtk_table_new(N_COUNTS, 3, TRUE);
1556 gtk_box_pack_start(GTK_BOX(main_vb), counts_tb, TRUE, TRUE, 3);
1557 gtk_widget_show(counts_tb);
1559 for (i = 0; i < N_COUNTS; i++) {
1560 counts[i].label = gtk_label_new(counts[i].title);
1561 gtk_misc_set_alignment(GTK_MISC(counts[i].label), 0.0f, 0.0f);
1563 counts[i].value = gtk_label_new("0");
1564 gtk_misc_set_alignment(GTK_MISC(counts[i].value), 0.0f, 0.0f);
1566 counts[i].percent = gtk_label_new("0.0%");
1567 gtk_misc_set_alignment(GTK_MISC(counts[i].percent), 0.0f, 0.0f);
1569 gtk_table_attach_defaults(GTK_TABLE(counts_tb),
1570 counts[i].label, 0, 1, i, i + 1);
1572 gtk_table_attach(GTK_TABLE(counts_tb),
1574 1, 2, i, i + 1, 0, 0, 5, 0);
1576 gtk_table_attach_defaults(GTK_TABLE(counts_tb),
1577 counts[i].percent, 2, 3, i, i + 1);
1579 gtk_widget_show(counts[i].label);
1580 gtk_widget_show(counts[i].value);
1581 gtk_widget_show(counts[i].percent);
1584 /* allow user to either click a stop button, or the close button on
1585 the window to stop a capture in progress. */
1586 stop_bt = gtk_button_new_with_label ("Stop");
1587 gtk_signal_connect(GTK_OBJECT(stop_bt), "clicked",
1588 GTK_SIGNAL_FUNC(capture_stop_cb), (gpointer) &ld);
1589 gtk_signal_connect(GTK_OBJECT(cap_w), "delete_event",
1590 GTK_SIGNAL_FUNC(capture_delete_cb), (gpointer) &ld);
1591 gtk_box_pack_end(GTK_BOX(main_vb), stop_bt, FALSE, FALSE, 3);
1592 GTK_WIDGET_SET_FLAGS(stop_bt, GTK_CAN_DEFAULT);
1593 gtk_widget_grab_default(stop_bt);
1594 GTK_WIDGET_SET_FLAGS(stop_bt, GTK_CAN_DEFAULT);
1595 gtk_widget_grab_default(stop_bt);
1596 gtk_widget_show(stop_bt);
1598 gtk_widget_show(cap_w);
1600 upd_time = time(NULL);
1601 #ifdef MUST_DO_SELECT
1602 if (!ld.from_pipe) pcap_fd = pcap_fileno(pch);
1607 * Catch SIGUSR1, so that we exit cleanly if the parent process
1608 * kills us with it due to the user selecting "Capture->Stop".
1610 signal(SIGUSR1, stop_capture);
1612 /* initialize capture stop conditions */
1613 init_capture_stop_conditions();
1614 /* create stop conditions */
1615 if (capture_opts.has_autostop_filesize)
1616 cnd_stop_capturesize =
1617 cnd_new(CND_CLASS_CAPTURESIZE,(long)capture_opts.autostop_filesize * 1000);
1618 if (capture_opts.has_autostop_duration)
1620 cnd_new(CND_CLASS_TIMEOUT,(gint32)capture_opts.autostop_duration);
1623 while (gtk_events_pending()) gtk_main_iteration();
1628 FD_SET(pipe_fd, &set1);
1630 timeout.tv_usec = CAP_READ_TIMEOUT*1000;
1631 if (select(pipe_fd+1, &set1, NULL, NULL, &timeout) != 0) {
1633 * "select()" says we can read from the pipe without blocking; go for
1634 * it. We are not sure we can read a whole record, but at least the
1635 * begninning of one. pipe_dispatch() will block reading the whole
1638 inpkts = pipe_dispatch(pipe_fd, &ld, &hdr);
1645 #ifdef MUST_DO_SELECT
1647 * Sigh. The semantics of the read timeout argument to
1648 * "pcap_open_live()" aren't particularly well specified by
1649 * the "pcap" man page - at least with the BSD BPF code, the
1650 * intent appears to be, at least in part, a way of cutting
1651 * down the number of reads done on a capture, by blocking
1652 * until the buffer fills or a timer expires - and the Linux
1653 * libpcap doesn't actually support it, so we can't use it
1654 * to break out of the "pcap_dispatch()" every 1/4 of a second
1655 * or so. Linux's libpcap is not the only libpcap that doesn't
1656 * support the read timeout.
1658 * Furthermore, at least on Solaris, the bufmod STREAMS module's
1659 * read timeout won't go off if no data has arrived, i.e. it cannot
1660 * be used to guarantee that a read from a DLPI stream will return
1661 * within a specified amount of time regardless of whether any
1662 * data arrives or not.
1664 * Thus, on all platforms other than BSD, we do a "select()" on the
1665 * file descriptor for the capture, with a timeout of CAP_READ_TIMEOUT
1666 * milliseconds, or CAP_READ_TIMEOUT*1000 microseconds.
1668 * "select()", on BPF devices, doesn't work as you might expect;
1669 * at least on some versions of some flavors of BSD, the timer
1670 * doesn't start until a read is done, so it won't expire if
1671 * only a "select()" or "poll()" is posted.
1674 FD_SET(pcap_fd, &set1);
1676 timeout.tv_usec = CAP_READ_TIMEOUT*1000;
1677 if (select(pcap_fd+1, &set1, NULL, NULL, &timeout) != 0) {
1679 * "select()" says we can read from it without blocking; go for
1682 inpkts = pcap_dispatch(pch, 1, capture_pcap_cb, (u_char *) &ld);
1690 inpkts = pcap_dispatch(pch, 1, capture_pcap_cb, (u_char *) &ld);
1698 ld.sync_packets += inpkts;
1699 /* check capture stop conditons */
1700 if (cnd_stop_timeout != NULL && cnd_eval(cnd_stop_timeout)) {
1701 /* The specified capture time has elapsed; stop the capture. */
1703 } else if (cnd_stop_capturesize != NULL && cnd_eval(cnd_stop_capturesize,
1704 (guint32)wtap_get_bytes_dumped(ld.pdh))){
1705 /* Capture file reached its maximum size. */
1706 if (capture_opts.ringbuffer_on) {
1707 /* Switch to the next ringbuffer file */
1708 if (ringbuf_switch_file(&cfile, &ld.pdh, &ld.err)) {
1709 /* File switch succeeded: reset the condition */
1710 cnd_reset(cnd_stop_capturesize);
1712 /* File switch failed: stop here */
1717 /* no ringbuffer - just stop */
1721 /* Only update once a second so as not to overload slow displays */
1722 cur_time = time(NULL);
1723 if (cur_time > upd_time) {
1724 upd_time = cur_time;
1726 for (i = 0; i < N_COUNTS; i++) {
1727 snprintf(label_str, sizeof(label_str), "%d",
1728 *counts[i].value_ptr);
1730 gtk_label_set(GTK_LABEL(counts[i].value), label_str);
1732 snprintf(label_str, sizeof(label_str), "(%.1f%%)",
1733 pct(*counts[i].value_ptr, ld.counts.total));
1735 gtk_label_set(GTK_LABEL(counts[i].percent), label_str);
1738 /* do sync here, too */
1739 fflush(wtap_dump_file(ld.pdh));
1740 if (capture_child && ld.sync_packets) {
1741 /* This is the child process for a sync mode capture, so send
1742 our parent a message saying we've written out "ld.sync_packets"
1743 packets to the capture file. */
1745 sprintf(tmp, "%d%c", ld.sync_packets, SP_PACKET_COUNT);
1746 write(1, tmp, strlen(tmp));
1747 ld.sync_packets = 0;
1752 /* delete stop conditions */
1753 if (cnd_stop_capturesize != NULL)
1754 cnd_delete(cnd_stop_capturesize);
1755 if (cnd_stop_timeout != NULL)
1756 cnd_delete(cnd_stop_timeout);
1759 snprintf(errmsg, sizeof(errmsg), "Error while capturing packets: %s",
1761 if (capture_child) {
1762 /* Tell the parent, so that they can pop up the message;
1763 we're going to exit, so if we try to pop it up, either
1764 it won't pop up or it'll disappear as soon as we exit. */
1765 send_errmsg_to_parent(errmsg);
1767 /* Just pop up the message ourselves. */
1768 simple_dialog(ESD_TYPE_WARN, NULL, "%s", errmsg);
1773 get_capture_file_io_error(errmsg, sizeof(errmsg), cfile.save_file, ld.err,
1775 if (capture_child) {
1776 /* Tell the parent, so that they can pop up the message;
1777 we're going to exit, so if we try to pop it up, either
1778 it won't pop up or it'll disappear as soon as we exit. */
1779 send_errmsg_to_parent(errmsg);
1781 /* Just pop up the message ourselves. */
1782 simple_dialog(ESD_TYPE_WARN, NULL, "%s", errmsg);
1785 /* A write failed, so we've already told the user there's a problem;
1786 if the close fails, there's no point in telling them about that
1788 if (capture_opts.ringbuffer_on) {
1789 ringbuf_wtap_dump_close(&cfile, &err);
1791 wtap_dump_close(ld.pdh, &err);
1794 if (capture_opts.ringbuffer_on) {
1795 dump_ok = ringbuf_wtap_dump_close(&cfile, &err);
1797 dump_ok = wtap_dump_close(ld.pdh, &err);
1800 get_capture_file_io_error(errmsg, sizeof(errmsg), cfile.save_file, err,
1802 if (capture_child) {
1803 /* Tell the parent, so that they can pop up the message;
1804 we're going to exit, so if we try to pop it up, either
1805 it won't pop up or it'll disappear as soon as we exit. */
1806 send_errmsg_to_parent(errmsg);
1808 /* Just pop up the message ourselves. */
1809 simple_dialog(ESD_TYPE_WARN, NULL, "%s", errmsg);
1819 /* Get the capture statistics, so we know how many packets were
1821 if (pcap_stats(pch, stats) >= 0) {
1822 *stats_known = TRUE;
1823 if (capture_child) {
1824 /* Let the parent process know. */
1826 sprintf(tmp, "%d%c", stats->ps_drop, SP_DROPS);
1827 write(1, tmp, strlen(tmp));
1830 snprintf(errmsg, sizeof(errmsg),
1831 "Can't get packet-drop statistics: %s",
1833 if (capture_child) {
1834 /* Tell the parent, so that they can pop up the message;
1835 we're going to exit, so if we try to pop it up, either
1836 it won't pop up or it'll disappear as soon as we exit. */
1837 send_errmsg_to_parent(errmsg);
1839 /* Just pop up the message ourselves. */
1840 simple_dialog(ESD_TYPE_WARN, NULL, "%s", errmsg);
1847 /* Shut down windows sockets */
1851 gtk_grab_remove(GTK_WIDGET(cap_w));
1852 gtk_widget_destroy(GTK_WIDGET(cap_w));
1857 if (capture_opts.ringbuffer_on) {
1858 /* cleanup ringbuffer */
1859 ringbuf_error_cleanup();
1861 /* We can't use the save file, and we have no wtap_dump stream
1862 to close in order to close it, so close the FD directly. */
1863 close(cfile.save_file_fd);
1865 /* We couldn't even start the capture, so get rid of the capture
1867 unlink(cfile.save_file); /* silently ignore error */
1868 g_free(cfile.save_file);
1870 cfile.save_file = NULL;
1871 if (capture_child) {
1872 /* This is the child process for a sync mode capture.
1873 Send the error message to our parent, so they can display a
1874 dialog box containing it. */
1875 send_errmsg_to_parent(errmsg);
1877 /* Display the dialog box ourselves; there's no parent. */
1878 simple_dialog(ESD_TYPE_CRIT, NULL, "%s", errmsg);
1880 if (pch != NULL && !ld.from_pipe)
1887 get_capture_file_io_error(char *errmsg, int errmsglen, const char *fname,
1888 int err, gboolean is_close)
1893 snprintf(errmsg, errmsglen,
1894 "Not all the packets could be written to the file"
1895 " to which the capture was being saved\n"
1896 "(\"%s\") because there is no space left on the file system\n"
1897 "on which that file resides.",
1903 snprintf(errmsg, errmsglen,
1904 "Not all the packets could be written to the file"
1905 " to which the capture was being saved\n"
1906 "(\"%s\") because you are too close to, or over,"
1907 " your disk quota\n"
1908 "on the file system on which that file resides.",
1913 case WTAP_ERR_CANT_CLOSE:
1914 snprintf(errmsg, errmsglen,
1915 "The file to which the capture was being saved"
1916 " couldn't be closed for some unknown reason.");
1919 case WTAP_ERR_SHORT_WRITE:
1920 snprintf(errmsg, errmsglen,
1921 "Not all the packets could be written to the file"
1922 " to which the capture was being saved\n"
1929 snprintf(errmsg, errmsglen,
1930 "The file to which the capture was being saved\n"
1931 "(\"%s\") could not be closed: %s.",
1932 fname, wtap_strerror(err));
1934 snprintf(errmsg, errmsglen,
1935 "An error occurred while writing to the file"
1936 " to which the capture was being saved\n"
1938 fname, wtap_strerror(err));
1945 send_errmsg_to_parent(const char *errmsg)
1947 int msglen = strlen(errmsg);
1948 char lenbuf[10+1+1];
1950 sprintf(lenbuf, "%u%c", msglen, SP_ERROR_MSG);
1951 write(1, lenbuf, strlen(lenbuf));
1952 write(1, errmsg, msglen);
1956 pct(gint num, gint denom) {
1958 return (float) num * 100.0 / (float) denom;
1965 stop_capture(int signo)
1971 capture_delete_cb(GtkWidget *w, GdkEvent *event, gpointer data) {
1972 capture_stop_cb(NULL, data);
1976 capture_stop_cb(GtkWidget *w, gpointer data) {
1977 loop_data *ld = (loop_data *) data;
1986 * XXX - find some way of signaling the child in Win32.
1989 if (fork_child != -1)
1990 kill(fork_child, SIGUSR1);
1995 kill_capture_child(void)
1998 * XXX - find some way of signaling the child in Win32.
2001 if (fork_child != -1)
2002 kill(fork_child, SIGTERM); /* SIGTERM so it can clean up if necessary */
2007 capture_pcap_cb(u_char *user, const struct pcap_pkthdr *phdr,
2009 struct wtap_pkthdr whdr;
2010 loop_data *ld = (loop_data *) user;
2013 if ((++ld->counts.total >= ld->max) && (ld->max > 0))
2018 /* "phdr->ts" may not necessarily be a "struct timeval" - it may
2019 be a "struct bpf_timeval", with member sizes wired to 32
2020 bits - and we may go that way ourselves in the future, so
2021 copy the members individually. */
2022 whdr.ts.tv_sec = phdr->ts.tv_sec;
2023 whdr.ts.tv_usec = phdr->ts.tv_usec;
2024 whdr.caplen = phdr->caplen;
2025 whdr.len = phdr->len;
2026 whdr.pkt_encap = ld->linktype;
2028 /* If this fails, set "ld->go" to FALSE, to stop the capture, and set
2029 "ld->err" to the error. */
2030 if (!wtap_dump(ld->pdh, &whdr, NULL, pd, &err)) {
2036 switch (ld->linktype) {
2037 case WTAP_ENCAP_ETHERNET:
2038 capture_eth(pd, 0, phdr->len, &ld->counts);
2040 case WTAP_ENCAP_FDDI:
2041 case WTAP_ENCAP_FDDI_BITSWAPPED:
2042 capture_fddi(pd, phdr->len, &ld->counts);
2044 case WTAP_ENCAP_PRISM_HEADER:
2045 capture_prism(pd, 0, phdr->len, &ld->counts);
2047 case WTAP_ENCAP_TOKEN_RING:
2048 capture_tr(pd, 0, phdr->len, &ld->counts);
2050 case WTAP_ENCAP_NULL:
2051 capture_null(pd, phdr->len, &ld->counts);
2053 case WTAP_ENCAP_PPP:
2054 capture_ppp_hdlc(pd, 0, phdr->len, &ld->counts);
2056 case WTAP_ENCAP_RAW_IP:
2057 capture_raw(pd, phdr->len, &ld->counts);
2059 case WTAP_ENCAP_SLL:
2060 capture_sll(pd, phdr->len, &ld->counts);
2062 case WTAP_ENCAP_LINUX_ATM_CLIP:
2063 capture_clip(pd, phdr->len, &ld->counts);
2065 case WTAP_ENCAP_LOCALTALK:
2066 capture_llap(pd, phdr->len, &ld->counts);
2068 /* XXX - FreeBSD may append 4-byte ATM pseudo-header to DLT_ATM_RFC1483,
2069 with LLC header following; we should implement it at some
2074 #endif /* HAVE_LIBPCAP */