2 * Routines for packet capture
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.
54 #include <epan/packet.h>
55 #include <epan/dfilter/dfilter.h>
58 #include "capture_sync.h"
59 #include "capture_ui_utils.h"
61 #include "pcap-util.h"
62 #include "alert_box.h"
63 #include "simple_dialog.h"
64 #include <epan/prefs.h>
65 #include "conditions.h"
66 #include "ringbuffer.h"
69 #include "capture-wpcap.h"
79 * @return TRUE if the capture starts successfully, FALSE otherwise.
82 capture_start(capture_options *capture_opts)
87 /* close the currently loaded capture file */
88 cf_close(capture_opts->cf);
90 g_assert(capture_opts->state == CAPTURE_STOPPED);
91 capture_opts->state = CAPTURE_PREPARING;
93 g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "Capture Start ...");
95 /* try to start the capture child process */
96 ret = sync_pipe_start(capture_opts);
98 if(capture_opts->save_file != NULL) {
99 g_free(capture_opts->save_file);
100 capture_opts->save_file = NULL;
103 capture_opts->state = CAPTURE_STOPPED;
105 /* the capture child might not respond shortly after bringing it up */
106 /* (especially it will block, if no input coming from an input capture pipe (e.g. mkfifo) is coming in) */
108 /* to prevent problems, bring the main GUI into "capture mode" right after successfully */
109 /* spawn/exec the capture child, without waiting for any response from it */
110 cf_callback_invoke(cf_cb_live_capture_prepared, capture_opts);
118 capture_stop(capture_options *capture_opts)
120 g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "Capture Stop ...");
122 cf_callback_invoke(cf_cb_live_capture_stopping, capture_opts);
124 /* stop the capture child gracefully */
125 sync_pipe_stop(capture_opts);
130 capture_restart(capture_options *capture_opts)
132 g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "Capture Restart");
134 capture_opts->restart = TRUE;
135 capture_stop(capture_opts);
140 capture_kill_child(capture_options *capture_opts)
142 g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_INFO, "Capture Kill");
144 /* kill the capture child */
145 sync_pipe_kill(capture_opts);
150 /* We've succeeded a (non real-time) capture, try to read it into a new capture file */
152 capture_input_read_all(capture_options *capture_opts, gboolean is_tempfile, gboolean drops_known,
158 /* Capture succeeded; attempt to open the capture file. */
159 if (cf_open(capture_opts->cf, capture_opts->save_file, is_tempfile, &err) != CF_OK) {
160 /* We're not doing a capture any more, so we don't have a save
165 /* Set the read filter to NULL. */
166 /* XXX - this is odd here, try to put it somewhere, where it fits better */
167 cf_set_rfcode(capture_opts->cf, NULL);
169 /* Get the packet-drop statistics.
171 XXX - there are currently no packet-drop statistics stored
172 in libpcap captures, and that's what we're reading.
174 At some point, we will add support in Wiretap to return
175 packet-drop statistics for capture file formats that store it,
176 and will make "cf_read()" get those statistics from Wiretap.
177 We clear the statistics (marking them as "not known") in
178 "cf_open()", and "cf_read()" will only fetch them and mark
179 them as known if Wiretap supplies them, so if we get the
180 statistics now, after calling "cf_open()" but before calling
181 "cf_read()", the values we store will be used by "cf_read()".
183 If a future libpcap capture file format stores the statistics,
184 we'll put them into the capture file that we write, and will
185 thus not have to set them here - "cf_read()" will get them from
186 the file and use them. */
188 cf_set_drops_known(capture_opts->cf, TRUE);
190 /* XXX - on some systems, libpcap doesn't bother filling in
191 "ps_ifdrop" - it doesn't even set it to zero - so we don't
192 bother looking at it.
194 Ideally, libpcap would have an interface that gave us
195 several statistics - perhaps including various interface
196 error statistics - and would tell us which of them it
197 supplies, allowing us to display only the ones it does. */
198 cf_set_drops(capture_opts->cf, drops);
201 /* read in the packet data */
202 switch (cf_read(capture_opts->cf)) {
206 /* Just because we got an error, that doesn't mean we were unable
207 to read any of the file; we handle what we could get from the
211 case CF_READ_ABORTED:
212 /* User wants to quit program. Exit by leaving the main loop,
213 so that any quit functions we registered get called. */
214 main_window_nested_quit();
218 /* if we didn't captured even a single packet, close the file again */
219 if(cf_packet_count(capture_opts->cf) == 0 && !capture_opts->restart) {
220 simple_dialog(ESD_TYPE_INFO, ESD_BTN_OK,
221 "%sNo packets captured!%s\n\n"
222 "As no data was captured, closing the %scapture file!",
223 simple_dialog_primary_start(), simple_dialog_primary_end(),
224 (cf_is_tempfile(capture_opts->cf)) ? "temporary " : "");
225 cf_close(capture_opts->cf);
231 /* capture child tells us, we have a new (or the first) capture file */
233 capture_input_new_file(capture_options *capture_opts, gchar *new_file)
235 gboolean is_tempfile;
239 if(capture_opts->state == CAPTURE_PREPARING) {
240 g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "Capture started!");
242 g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "File: \"%s\"", new_file);
244 g_assert(capture_opts->state == CAPTURE_PREPARING || capture_opts->state == CAPTURE_RUNNING);
246 /* free the old filename */
247 if(capture_opts->save_file != NULL) {
248 /* we start a new capture file, close the old one (if we had one before) */
249 if( ((capture_file *) capture_opts->cf)->state != FILE_CLOSED) {
250 cf_callback_invoke(cf_cb_live_capture_update_finished, capture_opts->cf);
251 cf_finish_tail(capture_opts->cf, &err);
252 cf_close(capture_opts->cf);
254 g_free(capture_opts->save_file);
256 cf_set_tempfile(capture_opts->cf, FALSE);
258 /* we didn't had a save_file before, must be a tempfile */
260 cf_set_tempfile(capture_opts->cf, TRUE);
263 /* save the new filename */
264 capture_opts->save_file = g_strdup(new_file);
266 /* if we are in real-time mode, open the new file now */
267 if(capture_opts->real_time_mode) {
268 /* Attempt to open the capture file and set up to read from it. */
269 switch(cf_start_tail(capture_opts->cf, capture_opts->save_file, is_tempfile, &err)) {
273 /* Don't unlink (delete) the save file - leave it around,
274 for debugging purposes. */
275 g_free(capture_opts->save_file);
276 capture_opts->save_file = NULL;
281 cf_callback_invoke(cf_cb_live_capture_update_started, capture_opts);
283 cf_callback_invoke(cf_cb_live_capture_fixed_started, capture_opts);
286 capture_opts->state = CAPTURE_RUNNING;
292 /* capture child tells us, we have new packets to read */
294 capture_input_new_packets(capture_options *capture_opts, int to_read)
299 g_assert(capture_opts->save_file);
301 if(capture_opts->real_time_mode) {
302 /* Read from the capture file the number of records the child told us
304 XXX - do something if this fails? */
305 switch (cf_continue_tail(capture_opts->cf, to_read, &err)) {
309 /* Just because we got an error, that doesn't mean we were unable
310 to read any of the file; we handle what we could get from the
313 XXX - abort on a read error? */
314 cf_callback_invoke(cf_cb_live_capture_update_continue, capture_opts->cf);
315 /* update the main window, so we get events (e.g. from the stop toolbar button) */
316 main_window_update();
319 case CF_READ_ABORTED:
320 /* Kill the child capture process; the user wants to exit, and we
321 shouldn't just leave it running. */
322 capture_kill_child(capture_opts);
329 /* capture child closed it's side ot the pipe, do the required cleanup */
331 capture_input_closed(capture_options *capture_opts)
336 g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "Capture stopped!");
337 g_assert(capture_opts->state == CAPTURE_PREPARING || capture_opts->state == CAPTURE_RUNNING);
339 /* if we didn't started the capture (happens if an error occured), do a fake start */
340 if(capture_opts->state == CAPTURE_PREPARING) {
341 if(capture_opts->real_time_mode) {
342 cf_callback_invoke(cf_cb_live_capture_update_started, capture_opts);
344 cf_callback_invoke(cf_cb_live_capture_fixed_started, capture_opts);
348 if(capture_opts->real_time_mode) {
349 /* first of all, we are not doing a capture any more */
350 cf_callback_invoke(cf_cb_live_capture_update_finished, capture_opts->cf);
352 /* Read what remains of the capture file, and finish the capture.
353 XXX - do something if this fails? */
354 switch (cf_finish_tail(capture_opts->cf, &err)) {
357 if(cf_packet_count(capture_opts->cf) == 0 && !capture_opts->restart) {
358 simple_dialog(ESD_TYPE_INFO, ESD_BTN_OK,
359 "%sNo packets captured!%s\n\n"
360 "As no data was captured, closing the %scapture file!",
361 simple_dialog_primary_start(), simple_dialog_primary_end(),
362 cf_is_tempfile(capture_opts->cf) ? "temporary " : "");
363 cf_close(capture_opts->cf);
367 /* Just because we got an error, that doesn't mean we were unable
368 to read any of the file; we handle what we could get from the
372 case CF_READ_ABORTED:
373 /* Exit by leaving the main loop, so that any quit functions
374 we registered get called. */
379 /* first of all, we are not doing a capture any more */
380 cf_callback_invoke(cf_cb_live_capture_fixed_finished, capture_opts->cf);
382 /* this is a normal mode capture and if no error happened, read in the capture file data */
383 if(capture_opts->save_file != NULL) {
384 capture_input_read_all(capture_opts, cf_is_tempfile(capture_opts->cf),
385 cf_get_drops_known(capture_opts->cf), cf_get_drops(capture_opts->cf));
389 capture_opts->state = CAPTURE_STOPPED;
391 /* if we couldn't open a capture file, there's nothing more for us to do */
392 if(capture_opts->save_file == NULL) {
393 cf_close(capture_opts->cf);
397 /* does the user wants to restart the current capture? */
398 if(capture_opts->restart) {
399 capture_opts->restart = FALSE;
401 unlink(capture_opts->save_file);
403 /* if it was a tempfile, throw away the old filename (so it will become a tempfile again) */
404 if(cf_is_tempfile(capture_opts->cf)) {
405 g_free(capture_opts->save_file);
406 capture_opts->save_file = NULL;
409 /* ... and start the capture again */
410 capture_start(capture_opts);
412 /* We're not doing a capture any more, so we don't have a save file. */
413 g_free(capture_opts->save_file);
414 capture_opts->save_file = NULL;
419 #endif /* HAVE_LIBPCAP */