Make Content-Length and Max-Forwards fields uints
[obnox/wireshark/wip.git] / capture-pcap-util-unix.c
1 /* capture-pcap-util-unix.c
2  * UN*X-specific utility routines for packet capture
3  *
4  * $Id$
5  *
6  * Wireshark - Network traffic analyzer
7  * By Gerald Combs <gerald@wireshark.org>
8  * Copyright 1998 Gerald Combs
9  *
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.
14  *
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.
19  *
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.
23  */
24
25 #ifdef HAVE_CONFIG_H
26 # include "config.h"
27 #endif
28
29 #include <glib.h>
30
31 #ifdef HAVE_LIBPCAP
32
33 #include <stdlib.h>
34 #include <string.h>
35 #include <stdio.h>
36 #include <errno.h>
37
38 #ifdef HAVE_UNISTD_H
39 #include <unistd.h>
40 #endif
41
42 #ifdef HAVE_SYS_SOCKET_H
43 #include <sys/socket.h>
44 #endif
45
46 #ifdef HAVE_SYS_IOCTL_H
47 #include <sys/ioctl.h>
48 #endif
49
50 #include <pcap.h>
51
52 /*
53  * Keep Digital UNIX happy when including <net/if.h>.
54  */
55 struct mbuf;
56 struct rtentry;
57 #include <net/if.h>
58
59 #ifdef HAVE_SYS_SOCKIO_H
60 # include <sys/sockio.h>
61 #endif
62
63 #include "capture-pcap-util.h"
64 #include "capture-pcap-util-int.h"
65
66 #ifndef HAVE_PCAP_FINDALLDEVS
67 struct search_user_data {
68         char    *name;
69         if_info_t *if_info;
70 };
71
72 static void
73 search_for_if_cb(gpointer data, gpointer user_data);
74 #endif
75
76 GList *
77 get_interface_list(int *err, char *err_str)
78 {
79 #ifdef HAVE_PCAP_FINDALLDEVS
80         return get_interface_list_findalldevs(err, err_str);
81 #else
82         GList  *il = NULL;
83         gint    nonloopback_pos = 0;
84         struct  ifreq *ifr, *last;
85         struct  ifconf ifc;
86         struct  ifreq ifrflags;
87         int     sock = socket(AF_INET, SOCK_DGRAM, 0);
88         struct search_user_data user_data;
89         pcap_t *pch;
90         int len, lastlen;
91         char *buf;
92         if_info_t *if_info;
93
94         if (sock < 0) {
95                 *err = CANT_GET_INTERFACE_LIST;
96                 g_snprintf(err_str, PCAP_ERRBUF_SIZE, "Error opening socket: %s",
97                     strerror(errno));
98                 return NULL;
99         }
100
101         /*
102          * This code came from: W. Richard Stevens: "UNIX Network Programming",
103          * Networking APIs: Sockets and XTI, Vol 1, page 434.
104          */
105         lastlen = 0;
106         len = 100 * sizeof(struct ifreq);
107         for ( ; ; ) {
108                 buf = g_malloc(len);
109                 ifc.ifc_len = len;
110                 ifc.ifc_buf = buf;
111                 memset (buf, 0, len);
112                 if (ioctl(sock, SIOCGIFCONF, &ifc) < 0) {
113                         if (errno != EINVAL || lastlen != 0) {
114                                 g_snprintf(err_str, PCAP_ERRBUF_SIZE,
115                                         "SIOCGIFCONF ioctl error getting list of interfaces: %s",
116                                         strerror(errno));
117                                 goto fail;
118                         }
119                 } else {
120                         if ((unsigned) ifc.ifc_len < sizeof(struct ifreq)) {
121                                 g_snprintf(err_str, PCAP_ERRBUF_SIZE,
122                                         "SIOCGIFCONF ioctl gave too small return buffer");
123                                 goto fail;
124                         }
125                         if (ifc.ifc_len == lastlen)
126                                 break;                  /* success, len has not changed */
127                         lastlen = ifc.ifc_len;
128                 }
129                 len += 10 * sizeof(struct ifreq);       /* increment */
130                 g_free(buf);
131         }
132         ifr = (struct ifreq *) ifc.ifc_req;
133         last = (struct ifreq *) ((char *) ifr + ifc.ifc_len);
134         while (ifr < last) {
135                 /*
136                  * Skip entries that begin with "dummy", or that include
137                  * a ":" (the latter are Solaris virtuals).
138                  */
139                 if (strncmp(ifr->ifr_name, "dummy", 5) == 0 ||
140                     strchr(ifr->ifr_name, ':') != NULL)
141                         goto next;
142
143                 /*
144                  * If we already have this interface name on the list,
145                  * don't add it, but, if we don't already have an IP
146                  * address for it, add that address (SIOCGIFCONF returns,
147                  * at least on BSD-flavored systems, one entry per
148                  * interface *address*; if an interface has multiple
149                  * addresses, we get multiple entries for it).
150                  */
151                 user_data.name = ifr->ifr_name;
152                 user_data.if_info = NULL;
153                 g_list_foreach(il, search_for_if_cb, &user_data);
154                 if (user_data.if_info != NULL) {
155                         if_info_add_address(user_data.if_info, &ifr->ifr_addr);
156                         goto next;
157                 }
158
159                 /*
160                  * Get the interface flags.
161                  */
162                 memset(&ifrflags, 0, sizeof ifrflags);
163                 strncpy(ifrflags.ifr_name, ifr->ifr_name,
164                     sizeof ifrflags.ifr_name);
165                 if (ioctl(sock, SIOCGIFFLAGS, (char *)&ifrflags) < 0) {
166                         if (errno == ENXIO)
167                                 goto next;
168                         g_snprintf(err_str, PCAP_ERRBUF_SIZE,
169                                 "SIOCGIFFLAGS error getting flags for interface %s: %s",
170                             ifr->ifr_name, strerror(errno));
171                         goto fail;
172                 }
173
174                 /*
175                  * Skip interfaces that aren't up.
176                  */
177                 if (!(ifrflags.ifr_flags & IFF_UP))
178                         goto next;
179
180                 /*
181                  * Skip interfaces that we can't open with "libpcap".
182                  * Open with the minimum packet size - it appears that the
183                  * IRIX SIOCSNOOPLEN "ioctl" may fail if the capture length
184                  * supplied is too large, rather than just truncating it.
185                  */
186                 pch = pcap_open_live(ifr->ifr_name, MIN_PACKET_SIZE, 0, 0,
187                     err_str);
188                 if (pch == NULL)
189                         goto next;
190                 pcap_close(pch);
191
192                 /*
193                  * If it's a loopback interface, add it at the end of the
194                  * list, otherwise add it after the last non-loopback
195                  * interface, so all loopback interfaces go at the end - we
196                  * don't want a loopback interface to be the default capture
197                  * device unless there are no non-loopback devices.
198                  */
199                 if_info = if_info_new(ifr->ifr_name, NULL);
200                 if_info_add_address(if_info, &ifr->ifr_addr);
201                 if ((ifrflags.ifr_flags & IFF_LOOPBACK) ||
202                     strncmp(ifr->ifr_name, "lo", 2) == 0) {
203                         if_info->loopback = TRUE;
204                         il = g_list_append(il, if_info);
205                 } else {
206                         if_info->loopback = FALSE;
207                         il = g_list_insert(il, if_info, nonloopback_pos);
208                         /*
209                          * Insert the next non-loopback interface after this
210                          * one.
211                          */
212                         nonloopback_pos++;
213                 }
214
215         next:
216 #ifdef HAVE_SA_LEN
217                 ifr = (struct ifreq *) ((char *) ifr +
218                     (ifr->ifr_addr.sa_len > sizeof(ifr->ifr_addr) ?
219                         ifr->ifr_addr.sa_len : sizeof(ifr->ifr_addr)) +
220                     IFNAMSIZ);
221 #else
222                 ifr = (struct ifreq *) ((char *) ifr + sizeof(struct ifreq));
223 #endif
224         }
225
226 #ifdef linux
227         /*
228          * OK, maybe we have support for the "any" device, to do a cooked
229          * capture on all interfaces at once.
230          * Try opening it and, if that succeeds, add it to the end of
231          * the list of interfaces.
232          */
233         pch = pcap_open_live("any", MIN_PACKET_SIZE, 0, 0, err_str);
234         if (pch != NULL) {
235                 /*
236                  * It worked; we can use the "any" device.
237                  */
238                 if_info = if_info_new("any",
239                     "Pseudo-device that captures on all interfaces");
240                 il = g_list_insert(il, if_info, -1);
241                 pcap_close(pch);
242         }
243 #endif
244
245         g_free(ifc.ifc_buf);
246         close(sock);
247
248         if (il == NULL) {
249                 /*
250                  * No interfaces found.
251                  */
252                 *err = NO_INTERFACES_FOUND;
253         }
254         return il;
255
256 fail:
257         if (il != NULL)
258                 free_interface_list(il);
259         g_free(ifc.ifc_buf);
260         close(sock);
261         *err = CANT_GET_INTERFACE_LIST;
262         return NULL;
263 #endif /* HAVE_PCAP_FINDALLDEVS */
264 }
265
266 #ifndef HAVE_PCAP_FINDALLDEVS
267 static void
268 search_for_if_cb(gpointer data, gpointer user_data)
269 {
270         struct search_user_data *search_user_data = user_data;
271         if_info_t *if_info = data;
272
273         if (strcmp(if_info->name, search_user_data->name) == 0)
274                 search_user_data->if_info = if_info;
275 }
276 #endif /* HAVE_PCAP_FINDALLDEVS */
277
278 /*
279  * Get an error message string for a CANT_GET_INTERFACE_LIST error from
280  * "get_interface_list()".
281  */
282 gchar *
283 cant_get_if_list_error_message(const char *err_str)
284 {
285         return g_strdup_printf("Can't get list of interfaces: %s", err_str);
286 }
287
288 /*
289  * Append the version of libpcap with which we were compiled to a GString.
290  */
291 void
292 get_compiled_pcap_version(GString *str)
293 {
294 #ifdef HAVE_PCAP_VERSION
295         extern char pcap_version[];
296
297         g_string_sprintfa(str, "with libpcap %s", pcap_version);
298 #else
299         g_string_append(str, "with libpcap (version unknown)");
300 #endif
301 }
302
303 /*
304  * Append the version of libpcap with which we we're running to a GString.
305  */
306 void
307 get_runtime_pcap_version(GString *str)
308 {
309         g_string_sprintfa(str, "with ");
310 #ifdef HAVE_PCAP_LIB_VERSION
311         g_string_sprintfa(str, pcap_lib_version());
312 #else
313         g_string_append(str, "libpcap (version unknown)");
314 #endif
315         g_string_append(str, " ");
316 }
317
318 #else /* HAVE_LIBPCAP */
319
320 /*
321  * Append an indication that we were not compiled with libpcap
322  * to a GString.
323  */
324 void
325 get_compiled_pcap_version(GString *str)
326 {
327         g_string_append(str, "without libpcap");
328 }
329
330 /*
331  * Don't append anything, as we weren't even compiled to use WinPcap.
332  */
333 void
334 get_runtime_pcap_version(GString *str _U_)
335 {
336 }
337
338 #endif /* HAVE_LIBPCAP */