2 * Routines for packet capture windows
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.
25 /* With MSVC and a libethereal.dll this file needs to import some variables
26 in a special way. Therefore _NEED_VAR_IMPORT_ is defined. */
27 #define _NEED_VAR_IMPORT_
53 #include <epan/packet.h>
54 #include <epan/dfilter/dfilter.h>
57 #include "capture_sync.h"
59 #include "pcap-util.h"
60 #include "alert_box.h"
61 #include "simple_dialog.h"
62 #include <epan/prefs.h>
64 #include "conditions.h"
65 #include "ringbuffer.h"
68 #include "capture-wpcap.h"
75 capture_options capture_opts;
76 gboolean capture_child; /* if this is the child for "-S" */
79 /* Win32 needs the O_BINARY flag for open() */
84 static gboolean normal_do_capture(gboolean is_tempfile);
85 static void stop_capture_signal_handler(int signo);
87 /* Open a specified file, or create a temporary file, and start a capture
88 to the file in question. Returns TRUE if the capture starts
89 successfully, FALSE otherwise. */
91 do_capture(const char *save_file)
98 if (save_file != NULL) {
99 /* If the Sync option is set, we return to the caller while the capture
100 * is in progress. Therefore we need to take a copy of save_file in
101 * case the caller destroys it after we return.
103 capfile_name = g_strdup(save_file);
104 if (capture_opts.multi_files_on) {
105 /* ringbuffer is enabled */
106 cfile.save_file_fd = ringbuf_init(capfile_name,
107 (capture_opts.has_ring_num_files) ? capture_opts.ring_num_files : 0);
109 /* Try to open/create the specified file for use as a capture buffer. */
110 cfile.save_file_fd = open(capfile_name, O_RDWR|O_BINARY|O_TRUNC|O_CREAT,
115 /* Choose a random name for the capture buffer */
116 cfile.save_file_fd = create_tempfile(tmpname, sizeof tmpname, "ether");
117 capfile_name = g_strdup(tmpname);
120 if (cfile.save_file_fd == -1) {
122 simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
123 "The temporary file to which the capture would be saved (\"%s\")"
124 "could not be opened: %s.", capfile_name, strerror(errno));
126 if (capture_opts.multi_files_on) {
127 ringbuf_error_cleanup();
129 open_failure_alert_box(capfile_name, errno, TRUE);
131 g_free(capfile_name);
135 g_assert(cfile.save_file == NULL);
136 cfile.save_file = capfile_name;
137 /* cfile.save_file is "g_free"ed below, which is equivalent to
138 "g_free(capfile_name)". */
140 if (capture_opts.sync_mode) {
141 /* sync mode: do the capture in a child process */
142 ret = sync_pipe_do_capture(is_tempfile);
143 /* capture is still running */
144 set_main_window_name("(Live Capture in Progress) - Ethereal");
146 /* normal mode: do the capture synchronously */
147 set_main_window_name("(Live Capture in Progress) - Ethereal");
148 ret = normal_do_capture(is_tempfile);
149 /* capture is finished here */
156 /* start a normal capture session */
158 normal_do_capture(gboolean is_tempfile)
160 int capture_succeeded;
161 gboolean stats_known;
162 struct pcap_stat stats;
166 capture_succeeded = capture_start(&stats_known, &stats);
167 if (capture_opts.quit_after_cap) {
168 /* DON'T unlink the save file. Presumably someone wants it. */
171 if (!capture_succeeded) {
172 /* We didn't succeed in doing the capture, so we don't have a save
174 if (capture_opts.multi_files_on) {
177 g_free(cfile.save_file);
179 cfile.save_file = NULL;
182 /* Capture succeeded; attempt to read in the capture file. */
183 if ((err = cf_open(cfile.save_file, is_tempfile, &cfile)) != 0) {
184 /* We're not doing a capture any more, so we don't have a save
186 if (capture_opts.multi_files_on) {
189 g_free(cfile.save_file);
191 cfile.save_file = NULL;
195 /* Set the read filter to NULL. */
198 /* Get the packet-drop statistics.
200 XXX - there are currently no packet-drop statistics stored
201 in libpcap captures, and that's what we're reading.
203 At some point, we will add support in Wiretap to return
204 packet-drop statistics for capture file formats that store it,
205 and will make "cf_read()" get those statistics from Wiretap.
206 We clear the statistics (marking them as "not known") in
207 "cf_open()", and "cf_read()" will only fetch them and mark
208 them as known if Wiretap supplies them, so if we get the
209 statistics now, after calling "cf_open()" but before calling
210 "cf_read()", the values we store will be used by "cf_read()".
212 If a future libpcap capture file format stores the statistics,
213 we'll put them into the capture file that we write, and will
214 thus not have to set them here - "cf_read()" will get them from
215 the file and use them. */
217 cfile.drops_known = TRUE;
219 /* XXX - on some systems, libpcap doesn't bother filling in
220 "ps_ifdrop" - it doesn't even set it to zero - so we don't
221 bother looking at it.
223 Ideally, libpcap would have an interface that gave us
224 several statistics - perhaps including various interface
225 error statistics - and would tell us which of them it
226 supplies, allowing us to display only the ones it does. */
227 cfile.drops = stats.ps_drop;
229 switch (cf_read(&cfile)) {
233 /* Just because we got an error, that doesn't mean we were unable
234 to read any of the file; we handle what we could get from the
239 /* Exit by leaving the main loop, so that any quit functions
240 we registered get called. */
241 main_window_nested_quit();
245 /* We're not doing a capture any more, so we don't have a save
247 if (capture_opts.multi_files_on) {
250 g_free(cfile.save_file);
252 cfile.save_file = NULL;
254 /* if we didn't captured even a single packet, close the file again */
255 if(cfile.count == 0) {
256 simple_dialog(ESD_TYPE_INFO, ESD_BTN_OK,
257 "%sNo packets captured!%s\n\n"
258 "As no data was captured, closing the %scapture file!",
259 simple_dialog_primary_start(), simple_dialog_primary_end(),
260 (cfile.is_tempfile) ? "temporary " : "");
268 stop_capture_signal_handler(int signo _U_)
275 capture_start(gboolean *stats_known, struct pcap_stat *stats)
279 * Catch SIGUSR1, so that we exit cleanly if the parent process
280 * kills us with it due to the user selecting "Capture->Stop".
283 signal(SIGUSR1, stop_capture_signal_handler);
286 return capture_loop_start(stats_known, stats);
293 if (capture_opts.sync_mode) {
301 kill_capture_child(void)
303 if (capture_opts.sync_mode) {
309 #endif /* HAVE_LIBPCAP */