2 * Routines for packet capture
6 * Wireshark - Network traffic analyzer
7 * By Gerald Combs <gerald@wireshark.org>
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.
40 #include <epan/packet.h>
41 #include <epan/dfilter/dfilter.h>
44 #include "capture_ifinfo.h"
45 #include "capture_sync.h"
46 #include "capture_info.h"
47 #include "capture_ui_utils.h"
49 #include "capture-pcap-util.h"
50 #include "simple_dialog.h"
51 #include <epan/prefs.h>
54 #include "capture-wpcap.h"
57 #include "wsutil/file_util.h"
60 typedef struct if_stat_cache_item_s {
63 } if_stat_cache_item_t;
65 struct if_stat_cache_s {
68 GList *cache_list; /* List of if_stat_chache_entry_t */
71 /* this callback mechanism should possibly be replaced by the g_signal_...() stuff (if I only would know how :-) */
73 capture_callback_t cb_fct;
75 } capture_callback_data_t;
77 static GList *capture_callbacks = NULL;
80 capture_callback_invoke(int event, capture_options *capture_opts)
82 capture_callback_data_t *cb;
83 GList *cb_item = capture_callbacks;
85 /* there should be at least one interested */
86 g_assert(cb_item != NULL);
88 while(cb_item != NULL) {
90 cb->cb_fct(event, capture_opts, cb->user_data);
91 cb_item = g_list_next(cb_item);
97 capture_callback_add(capture_callback_t func, gpointer user_data)
99 capture_callback_data_t *cb;
101 cb = g_malloc(sizeof(capture_callback_data_t));
103 cb->user_data = user_data;
105 capture_callbacks = g_list_append(capture_callbacks, cb);
109 capture_callback_remove(capture_callback_t func)
111 capture_callback_data_t *cb;
112 GList *cb_item = capture_callbacks;
114 while(cb_item != NULL) {
116 if(cb->cb_fct == func) {
117 capture_callbacks = g_list_remove(capture_callbacks, cb);
121 cb_item = g_list_next(cb_item);
124 g_assert_not_reached();
130 * @return TRUE if the capture starts successfully, FALSE otherwise.
133 capture_start(capture_options *capture_opts)
136 GString *source = g_string_new("");
138 /* close the currently loaded capture file */
139 cf_close(capture_opts->cf);
141 g_assert(capture_opts->state == CAPTURE_STOPPED);
142 capture_opts->state = CAPTURE_PREPARING;
144 g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "Capture Start ...");
146 g_string_printf(source, "%s", get_iface_description(capture_opts));
147 if(capture_opts->cfilter && capture_opts->cfilter[0]) {
148 g_string_append_printf(source, " (%s)", capture_opts->cfilter);
150 cf_set_tempfile_source(capture_opts->cf, source->str);
151 g_string_free(source, TRUE);
153 /* try to start the capture child process */
154 ret = sync_pipe_start(capture_opts);
156 if(capture_opts->save_file != NULL) {
157 g_free(capture_opts->save_file);
158 capture_opts->save_file = NULL;
161 g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "Capture Start failed!");
162 capture_opts->state = CAPTURE_STOPPED;
164 /* the capture child might not respond shortly after bringing it up */
165 /* (for example: it will block if no input arrives from an input capture pipe (e.g. mkfifo)) */
167 /* to prevent problems, bring the main GUI into "capture mode" right after a successful */
168 /* spawn/exec of the capture child, without waiting for any response from it */
169 capture_callback_invoke(capture_cb_capture_prepared, capture_opts);
171 if(capture_opts->show_info)
172 capture_info_open(capture_opts);
180 capture_stop(capture_options *capture_opts)
182 g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "Capture Stop ...");
184 capture_callback_invoke(capture_cb_capture_stopping, capture_opts);
186 /* stop the capture child gracefully */
187 sync_pipe_stop(capture_opts);
192 capture_restart(capture_options *capture_opts)
194 g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "Capture Restart");
196 capture_opts->restart = TRUE;
197 capture_stop(capture_opts);
202 capture_kill_child(capture_options *capture_opts)
204 g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_INFO, "Capture Kill");
206 /* kill the capture child */
207 sync_pipe_kill(capture_opts->fork_child);
212 /* We've succeeded in doing a (non real-time) capture; try to read it into a new capture file */
214 capture_input_read_all(capture_options *capture_opts, gboolean is_tempfile, gboolean drops_known,
219 /* Capture succeeded; attempt to open the capture file. */
220 if (cf_open(capture_opts->cf, capture_opts->save_file, is_tempfile, &err) != CF_OK) {
221 /* We're not doing a capture any more, so we don't have a save file. */
225 /* Set the read filter to NULL. */
226 /* XXX - this is odd here; try to put it somewhere where it fits better */
227 cf_set_rfcode(capture_opts->cf, NULL);
229 /* Get the packet-drop statistics.
231 XXX - there are currently no packet-drop statistics stored
232 in libpcap captures, and that's what we're reading.
234 At some point, we will add support in Wiretap to return
235 packet-drop statistics for capture file formats that store it,
236 and will make "cf_read()" get those statistics from Wiretap.
237 We clear the statistics (marking them as "not known") in
238 "cf_open()", and "cf_read()" will only fetch them and mark
239 them as known if Wiretap supplies them, so if we get the
240 statistics now, after calling "cf_open()" but before calling
241 "cf_read()", the values we store will be used by "cf_read()".
243 If a future libpcap capture file format stores the statistics,
244 we'll put them into the capture file that we write, and will
245 thus not have to set them here - "cf_read()" will get them from
246 the file and use them. */
248 cf_set_drops_known(capture_opts->cf, TRUE);
250 /* XXX - on some systems, libpcap doesn't bother filling in
251 "ps_ifdrop" - it doesn't even set it to zero - so we don't
252 bother looking at it.
254 Ideally, libpcap would have an interface that gave us
255 several statistics - perhaps including various interface
256 error statistics - and would tell us which of them it
257 supplies, allowing us to display only the ones it does. */
258 cf_set_drops(capture_opts->cf, drops);
261 /* read in the packet data */
262 switch (cf_read(capture_opts->cf, FALSE)) {
266 /* Just because we got an error, that doesn't mean we were unable
267 to read any of the file; we handle what we could get from the
271 case CF_READ_ABORTED:
272 /* User wants to quit program. Exit by leaving the main loop,
273 so that any quit functions we registered get called. */
274 main_window_nested_quit();
278 /* if we didn't capture even a single packet, close the file again */
279 if(cf_get_packet_count(capture_opts->cf) == 0 && !capture_opts->restart) {
280 simple_dialog(ESD_TYPE_INFO, ESD_BTN_OK,
281 "%sNo packets captured!%s\n"
283 "As no data was captured, closing the %scapture file!\n"
286 "Help about capturing can be found at:\n"
288 " http://wiki.wireshark.org/CaptureSetup"
291 "Wireless (Wi-Fi/WLAN):\n"
292 "Try to switch off promiscuous mode in the Capture Options!"
295 simple_dialog_primary_start(), simple_dialog_primary_end(),
296 (cf_is_tempfile(capture_opts->cf)) ? "temporary " : "");
297 cf_close(capture_opts->cf);
303 /* capture child tells us we have a new (or the first) capture file */
305 capture_input_new_file(capture_options *capture_opts, gchar *new_file)
307 gboolean is_tempfile;
310 if(capture_opts->state == CAPTURE_PREPARING) {
311 g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "Capture started!");
313 g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "File: \"%s\"", new_file);
315 g_assert(capture_opts->state == CAPTURE_PREPARING || capture_opts->state == CAPTURE_RUNNING);
317 /* free the old filename */
318 if(capture_opts->save_file != NULL) {
319 /* we start a new capture file, close the old one (if we had one before). */
320 /* (we can only have an open capture file in real_time_mode!) */
321 if( ((capture_file *) capture_opts->cf)->state != FILE_CLOSED) {
322 capture_callback_invoke(capture_cb_capture_update_finished, capture_opts);
323 cf_finish_tail(capture_opts->cf, &err);
324 cf_close(capture_opts->cf);
326 g_free(capture_opts->save_file);
328 cf_set_tempfile(capture_opts->cf, FALSE);
330 /* we didn't have a save_file before; must be a tempfile */
332 cf_set_tempfile(capture_opts->cf, TRUE);
335 /* save the new filename */
336 capture_opts->save_file = g_strdup(new_file);
338 /* if we are in real-time mode, open the new file now */
339 if(capture_opts->real_time_mode) {
340 /* Attempt to open the capture file and set up to read from it. */
341 switch(cf_start_tail(capture_opts->cf, capture_opts->save_file, is_tempfile, &err)) {
345 /* Don't unlink (delete) the save file - leave it around,
346 for debugging purposes. */
347 g_free(capture_opts->save_file);
348 capture_opts->save_file = NULL;
353 if(capture_opts->show_info) {
354 if (!capture_info_new_file(new_file))
358 if(capture_opts->real_time_mode) {
359 capture_callback_invoke(capture_cb_capture_update_started, capture_opts);
361 capture_callback_invoke(capture_cb_capture_fixed_started, capture_opts);
363 capture_opts->state = CAPTURE_RUNNING;
369 /* capture child tells us we have new packets to read */
371 capture_input_new_packets(capture_options *capture_opts, int to_read)
376 g_assert(capture_opts->save_file);
378 if(capture_opts->real_time_mode) {
379 /* Read from the capture file the number of records the child told us it added. */
380 switch (cf_continue_tail(capture_opts->cf, to_read, &err)) {
384 /* Just because we got an error, that doesn't mean we were unable
385 to read any of the file; we handle what we could get from the
388 XXX - abort on a read error? */
389 capture_callback_invoke(capture_cb_capture_update_continue, capture_opts);
392 case CF_READ_ABORTED:
393 /* Kill the child capture process; the user wants to exit, and we
394 shouldn't just leave it running. */
395 capture_kill_child(capture_opts);
399 /* increase the capture file packet counter by the number of incoming packets */
400 cf_set_packet_count(capture_opts->cf,
401 cf_get_packet_count(capture_opts->cf) + to_read);
403 capture_callback_invoke(capture_cb_capture_fixed_continue, capture_opts);
406 /* update the main window so we get events (e.g. from the stop toolbar button) */
407 main_window_update();
409 if(capture_opts->show_info)
410 capture_info_new_packets(to_read);
414 /* Capture child told us how many dropped packets it counted.
417 capture_input_drops(capture_options *capture_opts, guint32 dropped)
419 g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_INFO, "%u packet%s dropped", dropped, plurality(dropped, "", "s"));
421 g_assert(capture_opts->state == CAPTURE_RUNNING);
423 cf_set_drops_known(capture_opts->cf, TRUE);
424 cf_set_drops(capture_opts->cf, dropped);
428 /* Capture child told us that an error has occurred while starting/running
430 The buffer we're handed has *two* null-terminated strings in it - a
431 primary message and a secondary message, one right after the other.
432 The secondary message might be a null string.
435 capture_input_error_message(capture_options *capture_opts, char *error_msg, char *secondary_error_msg)
437 gchar *safe_error_msg;
438 gchar *safe_secondary_error_msg;
440 g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "Error message from child: \"%s\", \"%s\"",
441 error_msg, secondary_error_msg);
443 g_assert(capture_opts->state == CAPTURE_PREPARING || capture_opts->state == CAPTURE_RUNNING);
445 safe_error_msg = simple_dialog_format_message(error_msg);
446 if (*secondary_error_msg != '\0') {
447 /* We have both primary and secondary messages. */
448 safe_secondary_error_msg = simple_dialog_format_message(secondary_error_msg);
449 simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK, "%s%s%s\n\n%s",
450 simple_dialog_primary_start(), safe_error_msg,
451 simple_dialog_primary_end(), safe_secondary_error_msg);
452 g_free(safe_secondary_error_msg);
454 /* We have only a primary message. */
455 simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK, "%s%s%s",
456 simple_dialog_primary_start(), safe_error_msg,
457 simple_dialog_primary_end());
459 g_free(safe_error_msg);
461 /* the capture child will close the sync_pipe if required, nothing to do for now */
466 /* Capture child told us that an error has occurred while parsing a
467 capture filter when starting/running the capture.
470 capture_input_cfilter_error_message(capture_options *capture_opts, char *error_message)
472 dfilter_t *rfcode = NULL;
473 gchar *safe_cfilter = simple_dialog_format_message(capture_opts->cfilter);
474 gchar *safe_cfilter_error_msg = simple_dialog_format_message(error_message);
476 g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "Capture filter error message from child: \"%s\"", error_message);
478 g_assert(capture_opts->state == CAPTURE_PREPARING || capture_opts->state == CAPTURE_RUNNING);
480 /* Did the user try a display filter? */
481 if (dfilter_compile(capture_opts->cfilter, &rfcode) && rfcode != NULL) {
482 simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
483 "%sInvalid capture filter: \"%s\"!%s\n"
485 "That string looks like a valid display filter; however, it isn't a valid\n"
486 "capture filter (%s).\n"
488 "Note that display filters and capture filters don't have the same syntax,\n"
489 "so you can't use most display filter expressions as capture filters.\n"
491 "See the User's Guide for a description of the capture filter syntax.",
492 simple_dialog_primary_start(), safe_cfilter,
493 simple_dialog_primary_end(), safe_cfilter_error_msg);
494 dfilter_free(rfcode);
496 simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
497 "%sInvalid capture filter: \"%s\"!%s\n"
499 "That string isn't a valid capture filter (%s).\n"
500 "See the User's Guide for a description of the capture filter syntax.",
501 simple_dialog_primary_start(), safe_cfilter,
502 simple_dialog_primary_end(), safe_cfilter_error_msg);
504 g_free(safe_cfilter_error_msg);
505 g_free(safe_cfilter);
507 /* the capture child will close the sync_pipe if required, nothing to do for now */
511 /* capture child closed its side of the pipe, do the required cleanup */
513 capture_input_closed(capture_options *capture_opts)
516 int packet_count_save;
518 g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "Capture stopped!");
519 g_assert(capture_opts->state == CAPTURE_PREPARING || capture_opts->state == CAPTURE_RUNNING);
521 /* if we didn't start the capture, do a fake start. */
522 /* (happens if we got an error message - we won't get a filename then). */
523 if(capture_opts->state == CAPTURE_PREPARING) {
524 if(capture_opts->real_time_mode) {
525 capture_callback_invoke(capture_cb_capture_update_started, capture_opts);
527 capture_callback_invoke(capture_cb_capture_fixed_started, capture_opts);
531 if(capture_opts->real_time_mode) {
532 cf_read_status_t status;
534 /* Read what remains of the capture file. */
535 status = cf_finish_tail(capture_opts->cf, &err);
537 /* XXX: If -Q (quit-after-cap) then cf->count clr'd below so save it first */
538 packet_count_save = cf_get_packet_count(capture_opts->cf);
539 /* Tell the GUI we are not doing a capture any more.
540 Must be done after the cf_finish_tail(), so file lengths are
541 correctly displayed */
542 capture_callback_invoke(capture_cb_capture_update_finished, capture_opts);
544 /* Finish the capture. */
548 if ((packet_count_save == 0) && !capture_opts->restart) {
549 simple_dialog(ESD_TYPE_INFO, ESD_BTN_OK,
550 "%sNo packets captured!%s\n"
552 "As no data was captured, closing the %scapture file!\n"
555 "Help about capturing can be found at:\n"
557 " http://wiki.wireshark.org/CaptureSetup"
560 "Wireless (Wi-Fi/WLAN):\n"
561 "Try to switch off promiscuous mode in the Capture Options!"
564 simple_dialog_primary_start(), simple_dialog_primary_end(),
565 cf_is_tempfile(capture_opts->cf) ? "temporary " : "");
566 cf_close(capture_opts->cf);
570 /* Just because we got an error, that doesn't mean we were unable
571 to read any of the file; we handle what we could get from the
575 case CF_READ_ABORTED:
576 /* Exit by leaving the main loop, so that any quit functions
577 we registered get called. */
582 /* first of all, we are not doing a capture any more */
583 capture_callback_invoke(capture_cb_capture_fixed_finished, capture_opts);
585 /* this is a normal mode capture and if no error happened, read in the capture file data */
586 if(capture_opts->save_file != NULL) {
587 capture_input_read_all(capture_opts, cf_is_tempfile(capture_opts->cf),
588 cf_get_drops_known(capture_opts->cf), cf_get_drops(capture_opts->cf));
592 if(capture_opts->show_info)
593 capture_info_close();
595 capture_opts->state = CAPTURE_STOPPED;
597 /* if we couldn't open a capture file, there's nothing more for us to do */
598 if(capture_opts->save_file == NULL) {
599 cf_close(capture_opts->cf);
603 /* does the user wants to restart the current capture? */
604 if(capture_opts->restart) {
605 capture_opts->restart = FALSE;
607 ws_unlink(capture_opts->save_file);
609 /* if it was a tempfile, throw away the old filename (so it will become a tempfile again) */
610 if(cf_is_tempfile(capture_opts->cf)) {
611 g_free(capture_opts->save_file);
612 capture_opts->save_file = NULL;
615 /* ... and start the capture again */
616 capture_start(capture_opts);
618 /* We're not doing a capture any more, so we don't have a save file. */
619 g_free(capture_opts->save_file);
620 capture_opts->save_file = NULL;
625 capture_stat_start(GList *if_list) {
626 int stat_fd, fork_child;
628 if_stat_cache_t *sc = NULL;
631 if_stat_cache_item_t *sc_item;
633 /* Fire up dumpcap. */
635 * XXX - on systems with BPF, the number of BPF devices limits the
636 * number of devices on which you can capture simultaneously.
640 * 1) this might fail if you run out of BPF devices
644 * 2) opening every interface could leave too few BPF devices
645 * for *other* programs.
647 * It also means the system could end up getting a lot of traffic
648 * that it has to pass through the networking stack and capture
649 * mechanism, so opening all the devices and presenting packet
650 * counts might not always be a good idea.
652 if (sync_interface_stats_open(&stat_fd, &fork_child, &msg) == 0) {
653 sc = g_malloc(sizeof(if_stat_cache_t));
654 sc->stat_fd = stat_fd;
655 sc->fork_child = fork_child;
656 sc->cache_list = NULL;
658 /* Initialize the cache */
659 for (if_entry = if_list; if_entry != NULL; if_entry = g_list_next(if_entry)) {
660 if_info = if_entry->data;
661 sc_item = g_malloc0(sizeof(if_stat_cache_item_t));
662 sc_item->name = g_strdup(if_info->name);
663 sc->cache_list = g_list_append(sc->cache_list, sc_item);
669 #define MAX_STAT_LINE_LEN 500
672 capture_stat_cache_update(if_stat_cache_t *sc) {
673 gchar stat_line[MAX_STAT_LINE_LEN];
676 if_stat_cache_item_t *sc_item;
681 while (sync_pipe_gets_nonblock(sc->stat_fd, stat_line, MAX_STAT_LINE_LEN) > 0) {
682 g_strstrip(stat_line);
683 stat_parts = g_strsplit(stat_line, "\t", 3);
684 if (stat_parts[0] == NULL || stat_parts[1] == NULL ||
685 stat_parts[2] == NULL) {
686 g_strfreev(stat_parts);
689 for (sc_entry = sc->cache_list; sc_entry != NULL; sc_entry = g_list_next(sc_entry)) {
690 sc_item = sc_entry->data;
691 if (strcmp(sc_item->name, stat_parts[0]) == 0) {
692 sc_item->ps.ps_recv = (u_int) strtoul(stat_parts[1], NULL, 10);
693 sc_item->ps.ps_drop = (u_int) strtoul(stat_parts[2], NULL, 10);
696 g_strfreev(stat_parts);
701 capture_stats(if_stat_cache_t *sc, char *ifname, struct pcap_stat *ps) {
703 if_stat_cache_item_t *sc_item;
705 if (!sc || !ifname || !ps) {
709 capture_stat_cache_update(sc);
710 for (sc_entry = sc->cache_list; sc_entry != NULL; sc_entry = g_list_next(sc_entry)) {
711 sc_item = sc_entry->data;
712 if (strcmp(sc_item->name, ifname) == 0) {
713 memcpy(ps, &sc_item->ps, sizeof(struct pcap_stat));
721 capture_stat_stop(if_stat_cache_t *sc) {
723 if_stat_cache_item_t *sc_item;
729 sync_interface_stats_close(&sc->stat_fd, &sc->fork_child, &msg);
731 for (sc_entry = sc->cache_list; sc_entry != NULL; sc_entry = g_list_next(sc_entry)) {
732 sc_item = sc_entry->data;
733 g_free(sc_item->name);
739 #endif /* HAVE_LIBPCAP */