![Ulf Lamping](/assets/img/avatar_default.png)
I've also changed the way the secondary error message is transported from former "header message 0 secondary 0" to "header header message 0 header secondary 0" as that might be a bit more clearer, and I'll need it for further development anyway. I was using this while debugging and not recognizing the real problem - for about four hours :-(. I'll need this feature when doing the interface (and link layer type) browsing later (transferring this data from dumpcap to Ethereal) to get a full blown privilege seperation. svn path=/trunk/; revision=17608
566 lines
18 KiB
C
566 lines
18 KiB
C
/* capture.c
|
|
* Routines for packet capture
|
|
*
|
|
* $Id$
|
|
*
|
|
* Ethereal - Network traffic analyzer
|
|
* By Gerald Combs <gerald@ethereal.com>
|
|
* Copyright 1998 Gerald Combs
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version 2
|
|
* of the License, or (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
|
*/
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
# include "config.h"
|
|
#endif
|
|
|
|
#ifdef HAVE_LIBPCAP
|
|
|
|
#ifdef HAVE_UNISTD_H
|
|
#include <unistd.h>
|
|
#endif
|
|
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <ctype.h>
|
|
|
|
#ifdef HAVE_FCNTL_H
|
|
#include <fcntl.h>
|
|
#endif
|
|
|
|
#include <signal.h>
|
|
#include <errno.h>
|
|
|
|
#include <glib.h>
|
|
|
|
#include <epan/packet.h>
|
|
#include <epan/dfilter/dfilter.h>
|
|
#include "file.h"
|
|
#include "capture.h"
|
|
#include "capture_sync.h"
|
|
#include "capture_info.h"
|
|
#include "capture_ui_utils.h"
|
|
#include "util.h"
|
|
#include "capture-pcap-util.h"
|
|
#include "alert_box.h"
|
|
#include "simple_dialog.h"
|
|
#include <epan/prefs.h>
|
|
#include "conditions.h"
|
|
#include "ringbuffer.h"
|
|
|
|
#ifdef _WIN32
|
|
#include "capture-wpcap.h"
|
|
#endif
|
|
#include "ui_util.h"
|
|
#include "file_util.h"
|
|
#include "log.h"
|
|
|
|
|
|
|
|
/**
|
|
* Start a capture.
|
|
*
|
|
* @return TRUE if the capture starts successfully, FALSE otherwise.
|
|
*/
|
|
gboolean
|
|
capture_start(capture_options *capture_opts)
|
|
{
|
|
gboolean ret;
|
|
|
|
|
|
/* close the currently loaded capture file */
|
|
cf_close(capture_opts->cf);
|
|
|
|
g_assert(capture_opts->state == CAPTURE_STOPPED);
|
|
capture_opts->state = CAPTURE_PREPARING;
|
|
|
|
g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "Capture Start ...");
|
|
|
|
/* try to start the capture child process */
|
|
ret = sync_pipe_start(capture_opts);
|
|
if(!ret) {
|
|
if(capture_opts->save_file != NULL) {
|
|
g_free(capture_opts->save_file);
|
|
capture_opts->save_file = NULL;
|
|
}
|
|
|
|
g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "Capture Start failed!");
|
|
capture_opts->state = CAPTURE_STOPPED;
|
|
} else {
|
|
/* the capture child might not respond shortly after bringing it up */
|
|
/* (especially it will block, if no input coming from an input capture pipe (e.g. mkfifo) is coming in) */
|
|
|
|
/* to prevent problems, bring the main GUI into "capture mode" right after successfully */
|
|
/* spawn/exec the capture child, without waiting for any response from it */
|
|
cf_callback_invoke(cf_cb_live_capture_prepared, capture_opts);
|
|
|
|
if(capture_opts->show_info)
|
|
capture_info_open(capture_opts->iface);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
|
|
void
|
|
capture_stop(capture_options *capture_opts)
|
|
{
|
|
g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "Capture Stop ...");
|
|
|
|
cf_callback_invoke(cf_cb_live_capture_stopping, capture_opts);
|
|
|
|
/* stop the capture child gracefully */
|
|
sync_pipe_stop(capture_opts);
|
|
}
|
|
|
|
|
|
void
|
|
capture_restart(capture_options *capture_opts)
|
|
{
|
|
g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "Capture Restart");
|
|
|
|
capture_opts->restart = TRUE;
|
|
capture_stop(capture_opts);
|
|
}
|
|
|
|
|
|
void
|
|
capture_kill_child(capture_options *capture_opts)
|
|
{
|
|
g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_INFO, "Capture Kill");
|
|
|
|
/* kill the capture child */
|
|
sync_pipe_kill(capture_opts);
|
|
}
|
|
|
|
|
|
|
|
/* We've succeeded a (non real-time) capture, try to read it into a new capture file */
|
|
static gboolean
|
|
capture_input_read_all(capture_options *capture_opts, gboolean is_tempfile, gboolean drops_known,
|
|
guint32 drops)
|
|
{
|
|
int err;
|
|
|
|
|
|
/* Capture succeeded; attempt to open the capture file. */
|
|
if (cf_open(capture_opts->cf, capture_opts->save_file, is_tempfile, &err) != CF_OK) {
|
|
/* We're not doing a capture any more, so we don't have a save
|
|
file. */
|
|
return FALSE;
|
|
}
|
|
|
|
/* Set the read filter to NULL. */
|
|
/* XXX - this is odd here, try to put it somewhere, where it fits better */
|
|
cf_set_rfcode(capture_opts->cf, NULL);
|
|
|
|
/* Get the packet-drop statistics.
|
|
|
|
XXX - there are currently no packet-drop statistics stored
|
|
in libpcap captures, and that's what we're reading.
|
|
|
|
At some point, we will add support in Wiretap to return
|
|
packet-drop statistics for capture file formats that store it,
|
|
and will make "cf_read()" get those statistics from Wiretap.
|
|
We clear the statistics (marking them as "not known") in
|
|
"cf_open()", and "cf_read()" will only fetch them and mark
|
|
them as known if Wiretap supplies them, so if we get the
|
|
statistics now, after calling "cf_open()" but before calling
|
|
"cf_read()", the values we store will be used by "cf_read()".
|
|
|
|
If a future libpcap capture file format stores the statistics,
|
|
we'll put them into the capture file that we write, and will
|
|
thus not have to set them here - "cf_read()" will get them from
|
|
the file and use them. */
|
|
if (drops_known) {
|
|
cf_set_drops_known(capture_opts->cf, TRUE);
|
|
|
|
/* XXX - on some systems, libpcap doesn't bother filling in
|
|
"ps_ifdrop" - it doesn't even set it to zero - so we don't
|
|
bother looking at it.
|
|
|
|
Ideally, libpcap would have an interface that gave us
|
|
several statistics - perhaps including various interface
|
|
error statistics - and would tell us which of them it
|
|
supplies, allowing us to display only the ones it does. */
|
|
cf_set_drops(capture_opts->cf, drops);
|
|
}
|
|
|
|
/* read in the packet data */
|
|
switch (cf_read(capture_opts->cf)) {
|
|
|
|
case CF_READ_OK:
|
|
case CF_READ_ERROR:
|
|
/* Just because we got an error, that doesn't mean we were unable
|
|
to read any of the file; we handle what we could get from the
|
|
file. */
|
|
break;
|
|
|
|
case CF_READ_ABORTED:
|
|
/* User wants to quit program. Exit by leaving the main loop,
|
|
so that any quit functions we registered get called. */
|
|
main_window_nested_quit();
|
|
return FALSE;
|
|
}
|
|
|
|
/* if we didn't captured even a single packet, close the file again */
|
|
if(cf_get_packet_count(capture_opts->cf) == 0 && !capture_opts->restart) {
|
|
simple_dialog(ESD_TYPE_INFO, ESD_BTN_OK,
|
|
"%sNo packets captured!%s\n"
|
|
"\n"
|
|
"As no data was captured, closing the %scapture file!\n"
|
|
"\n"
|
|
"\n"
|
|
"Help about capturing can be found at:\n"
|
|
"\n"
|
|
" http://wiki.ethereal.com/CaptureSetup"
|
|
#ifdef _WIN32
|
|
"\n\n"
|
|
"Wireless (Wi-Fi/WLAN):\n"
|
|
"Try to switch off promiscuous mode in the Capture Options!"
|
|
#endif
|
|
"",
|
|
simple_dialog_primary_start(), simple_dialog_primary_end(),
|
|
(cf_is_tempfile(capture_opts->cf)) ? "temporary " : "");
|
|
cf_close(capture_opts->cf);
|
|
}
|
|
return TRUE;
|
|
}
|
|
|
|
|
|
/* capture child tells us we have a new (or the first) capture file */
|
|
gboolean
|
|
capture_input_new_file(capture_options *capture_opts, gchar *new_file)
|
|
{
|
|
gboolean is_tempfile;
|
|
int err;
|
|
|
|
|
|
if(capture_opts->state == CAPTURE_PREPARING) {
|
|
g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "Capture started!");
|
|
}
|
|
g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "File: \"%s\"", new_file);
|
|
|
|
g_assert(capture_opts->state == CAPTURE_PREPARING || capture_opts->state == CAPTURE_RUNNING);
|
|
|
|
/* free the old filename */
|
|
if(capture_opts->save_file != NULL) {
|
|
/* we start a new capture file, close the old one (if we had one before) */
|
|
/* (we can only have an open capture file in real_time_mode!) */
|
|
if( ((capture_file *) capture_opts->cf)->state != FILE_CLOSED) {
|
|
cf_callback_invoke(cf_cb_live_capture_update_finished, capture_opts->cf);
|
|
cf_finish_tail(capture_opts->cf, &err);
|
|
cf_close(capture_opts->cf);
|
|
}
|
|
g_free(capture_opts->save_file);
|
|
is_tempfile = FALSE;
|
|
cf_set_tempfile(capture_opts->cf, FALSE);
|
|
} else {
|
|
/* we didn't had a save_file before, must be a tempfile */
|
|
is_tempfile = TRUE;
|
|
cf_set_tempfile(capture_opts->cf, TRUE);
|
|
}
|
|
|
|
/* save the new filename */
|
|
capture_opts->save_file = g_strdup(new_file);
|
|
|
|
/* if we are in real-time mode, open the new file now */
|
|
if(capture_opts->real_time_mode) {
|
|
/* Attempt to open the capture file and set up to read from it. */
|
|
switch(cf_start_tail(capture_opts->cf, capture_opts->save_file, is_tempfile, &err)) {
|
|
case CF_OK:
|
|
break;
|
|
case CF_ERROR:
|
|
/* Don't unlink (delete) the save file - leave it around,
|
|
for debugging purposes. */
|
|
g_free(capture_opts->save_file);
|
|
capture_opts->save_file = NULL;
|
|
return FALSE;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if(capture_opts->show_info) {
|
|
if (!capture_info_new_file(new_file))
|
|
return FALSE;
|
|
}
|
|
|
|
if(capture_opts->real_time_mode) {
|
|
cf_callback_invoke(cf_cb_live_capture_update_started, capture_opts);
|
|
} else {
|
|
cf_callback_invoke(cf_cb_live_capture_fixed_started, capture_opts);
|
|
}
|
|
capture_opts->state = CAPTURE_RUNNING;
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
|
|
/* capture child tells us we have new packets to read */
|
|
void
|
|
capture_input_new_packets(capture_options *capture_opts, int to_read)
|
|
{
|
|
int err;
|
|
|
|
|
|
g_assert(capture_opts->save_file);
|
|
|
|
if(capture_opts->real_time_mode) {
|
|
/* Read from the capture file the number of records the child told us it added. */
|
|
switch (cf_continue_tail(capture_opts->cf, to_read, &err)) {
|
|
|
|
case CF_READ_OK:
|
|
case CF_READ_ERROR:
|
|
/* Just because we got an error, that doesn't mean we were unable
|
|
to read any of the file; we handle what we could get from the
|
|
file.
|
|
|
|
XXX - abort on a read error? */
|
|
cf_callback_invoke(cf_cb_live_capture_update_continue, capture_opts->cf);
|
|
break;
|
|
|
|
case CF_READ_ABORTED:
|
|
/* Kill the child capture process; the user wants to exit, and we
|
|
shouldn't just leave it running. */
|
|
capture_kill_child(capture_opts);
|
|
break;
|
|
}
|
|
} else {
|
|
/* increase capture file packet counter by the number or incoming packets */
|
|
cf_set_packet_count(capture_opts->cf,
|
|
cf_get_packet_count(capture_opts->cf) + to_read);
|
|
|
|
cf_callback_invoke(cf_cb_live_capture_fixed_continue, capture_opts->cf);
|
|
}
|
|
|
|
/* update the main window, so we get events (e.g. from the stop toolbar button) */
|
|
main_window_update();
|
|
|
|
if(capture_opts->show_info)
|
|
capture_info_new_packets(to_read);
|
|
}
|
|
|
|
|
|
/* Capture child told us how many dropped packets it counted.
|
|
*/
|
|
void
|
|
capture_input_drops(capture_options *capture_opts, int dropped)
|
|
{
|
|
g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_INFO, "%d packet%s dropped", dropped, plurality(dropped, "", "s"));
|
|
|
|
g_assert(capture_opts->state == CAPTURE_RUNNING);
|
|
|
|
cf_set_drops_known(capture_opts->cf, TRUE);
|
|
cf_set_drops(capture_opts->cf, dropped);
|
|
}
|
|
|
|
|
|
/* Capture child told us that an error has occurred while starting/running
|
|
the capture.
|
|
The buffer we're handed has *two* null-terminated strings in it - a
|
|
primary message and a secondary message, one right after the other.
|
|
The secondary message might be a null string.
|
|
*/
|
|
void
|
|
capture_input_error_message(capture_options *capture_opts, char *error_msg, char *secondary_error_msg)
|
|
{
|
|
gchar *safe_error_msg;
|
|
gchar *safe_secondary_error_msg;
|
|
|
|
g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "Error message from child: \"%s\", \"%s\"",
|
|
error_msg, secondary_error_msg);
|
|
|
|
g_assert(capture_opts->state == CAPTURE_PREPARING || capture_opts->state == CAPTURE_RUNNING);
|
|
|
|
safe_error_msg = simple_dialog_format_message(error_msg);
|
|
if (*secondary_error_msg != '\0') {
|
|
/* We have both primary and secondary messages. */
|
|
safe_secondary_error_msg = simple_dialog_format_message(secondary_error_msg);
|
|
simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK, "%s%s%s\n\n%s",
|
|
simple_dialog_primary_start(), safe_error_msg,
|
|
simple_dialog_primary_end(), safe_secondary_error_msg);
|
|
g_free(safe_secondary_error_msg);
|
|
} else {
|
|
/* We have only a primary message. */
|
|
simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK, "%s%s%s",
|
|
simple_dialog_primary_start(), safe_error_msg,
|
|
simple_dialog_primary_end());
|
|
}
|
|
g_free(safe_error_msg);
|
|
|
|
/* the capture child will close the sync_pipe if required, nothing to do for now */
|
|
}
|
|
|
|
|
|
|
|
/* Capture child told us that an error has occurred while parsing a
|
|
capture filter when starting/running the capture.
|
|
*/
|
|
void
|
|
capture_input_cfilter_error_message(capture_options *capture_opts, char *error_message)
|
|
{
|
|
dfilter_t *rfcode = NULL;
|
|
gchar *safe_cfilter = simple_dialog_format_message(capture_opts->cfilter);
|
|
gchar *safe_cfilter_error_msg = simple_dialog_format_message(error_message);
|
|
|
|
g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "Capture filter error message from child: \"%s\"", error_message);
|
|
|
|
g_assert(capture_opts->state == CAPTURE_PREPARING || capture_opts->state == CAPTURE_RUNNING);
|
|
|
|
/* Did the user try a display filter? */
|
|
if (dfilter_compile(capture_opts->cfilter, &rfcode) && rfcode != NULL) {
|
|
simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
|
|
"%sInvalid capture filter: \"%s\"!%s\n"
|
|
"\n"
|
|
"That string looks like a valid display filter; however, it isn't a valid\n"
|
|
"capture filter (%s).\n"
|
|
"\n"
|
|
"Note that display filters and capture filters don't have the same syntax,\n"
|
|
"so you can't use most display filter expressions as capture filters.\n"
|
|
"\n"
|
|
"See the User's Guide for a description of the capture filter syntax.",
|
|
simple_dialog_primary_start(), safe_cfilter,
|
|
simple_dialog_primary_end(), safe_cfilter_error_msg);
|
|
dfilter_free(rfcode);
|
|
} else {
|
|
simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
|
|
"%sInvalid capture filter: \"%s\"!%s\n"
|
|
"\n"
|
|
"That string isn't a valid capture filter (%s).\n"
|
|
"See the User's Guide for a description of the capture filter syntax.",
|
|
simple_dialog_primary_start(), safe_cfilter,
|
|
simple_dialog_primary_end(), safe_cfilter_error_msg);
|
|
}
|
|
g_free(safe_cfilter_error_msg);
|
|
g_free(safe_cfilter);
|
|
|
|
/* the capture child will close the sync_pipe if required, nothing to do for now */
|
|
}
|
|
|
|
|
|
/* capture child closed its side of the pipe, do the required cleanup */
|
|
void
|
|
capture_input_closed(capture_options *capture_opts)
|
|
{
|
|
int err;
|
|
|
|
|
|
g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "Capture stopped!");
|
|
g_assert(capture_opts->state == CAPTURE_PREPARING || capture_opts->state == CAPTURE_RUNNING);
|
|
|
|
/* if we didn't started the capture, do a fake start */
|
|
/* (happens if we got an error message - we won't get a filename then) */
|
|
if(capture_opts->state == CAPTURE_PREPARING) {
|
|
if(capture_opts->real_time_mode) {
|
|
cf_callback_invoke(cf_cb_live_capture_update_started, capture_opts);
|
|
} else {
|
|
cf_callback_invoke(cf_cb_live_capture_fixed_started, capture_opts);
|
|
}
|
|
}
|
|
|
|
if(capture_opts->real_time_mode) {
|
|
cf_read_status_t status;
|
|
|
|
/* Read what remains of the capture file. */
|
|
status = cf_finish_tail(capture_opts->cf, &err);
|
|
|
|
/* Tell the GUI, we are not doing a capture any more.
|
|
Must be done after the cf_finish_tail(), so file lengths are displayed
|
|
correct. */
|
|
cf_callback_invoke(cf_cb_live_capture_update_finished, capture_opts->cf);
|
|
|
|
/* Finish the capture. */
|
|
switch (status) {
|
|
|
|
case CF_READ_OK:
|
|
if(cf_get_packet_count(capture_opts->cf) == 0 && !capture_opts->restart) {
|
|
simple_dialog(ESD_TYPE_INFO, ESD_BTN_OK,
|
|
"%sNo packets captured!%s\n"
|
|
"\n"
|
|
"As no data was captured, closing the %scapture file!\n"
|
|
"\n"
|
|
"\n"
|
|
"Help about capturing can be found at:\n"
|
|
"\n"
|
|
" http://wiki.ethereal.com/CaptureSetup"
|
|
#ifdef _WIN32
|
|
"\n\n"
|
|
"Wireless (Wi-Fi/WLAN):\n"
|
|
"Try to switch off promiscuous mode in the Capture Options!"
|
|
#endif
|
|
"",
|
|
simple_dialog_primary_start(), simple_dialog_primary_end(),
|
|
cf_is_tempfile(capture_opts->cf) ? "temporary " : "");
|
|
cf_close(capture_opts->cf);
|
|
}
|
|
break;
|
|
case CF_READ_ERROR:
|
|
/* Just because we got an error, that doesn't mean we were unable
|
|
to read any of the file; we handle what we could get from the
|
|
file. */
|
|
break;
|
|
|
|
case CF_READ_ABORTED:
|
|
/* Exit by leaving the main loop, so that any quit functions
|
|
we registered get called. */
|
|
main_window_quit();
|
|
}
|
|
|
|
} else {
|
|
/* first of all, we are not doing a capture any more */
|
|
cf_callback_invoke(cf_cb_live_capture_fixed_finished, capture_opts->cf);
|
|
|
|
/* this is a normal mode capture and if no error happened, read in the capture file data */
|
|
if(capture_opts->save_file != NULL) {
|
|
capture_input_read_all(capture_opts, cf_is_tempfile(capture_opts->cf),
|
|
cf_get_drops_known(capture_opts->cf), cf_get_drops(capture_opts->cf));
|
|
}
|
|
}
|
|
|
|
if(capture_opts->show_info)
|
|
capture_info_close();
|
|
|
|
capture_opts->state = CAPTURE_STOPPED;
|
|
|
|
/* if we couldn't open a capture file, there's nothing more for us to do */
|
|
if(capture_opts->save_file == NULL) {
|
|
cf_close(capture_opts->cf);
|
|
return;
|
|
}
|
|
|
|
/* does the user wants to restart the current capture? */
|
|
if(capture_opts->restart) {
|
|
capture_opts->restart = FALSE;
|
|
|
|
eth_unlink(capture_opts->save_file);
|
|
|
|
/* if it was a tempfile, throw away the old filename (so it will become a tempfile again) */
|
|
if(cf_is_tempfile(capture_opts->cf)) {
|
|
g_free(capture_opts->save_file);
|
|
capture_opts->save_file = NULL;
|
|
}
|
|
|
|
/* ... and start the capture again */
|
|
capture_start(capture_opts);
|
|
} else {
|
|
/* We're not doing a capture any more, so we don't have a save file. */
|
|
g_free(capture_opts->save_file);
|
|
capture_opts->save_file = NULL;
|
|
}
|
|
}
|
|
|
|
|
|
#endif /* HAVE_LIBPCAP */
|