/* capture.c * Routines for packet capture * * $Id$ * * Ethereal - Network traffic analyzer * By Gerald Combs * 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 #include #include #include #ifdef HAVE_FCNTL_H #include #endif #ifdef HAVE_IO_H # include #endif #include #include #include #include #include #include #include "file.h" #include "capture.h" #include "capture_sync.h" #include "capture_ui_utils.h" #include "util.h" #include "pcap-util.h" #include "alert_box.h" #include "simple_dialog.h" #include #include "conditions.h" #include "ringbuffer.h" #ifdef _WIN32 #include "capture-wpcap.h" #endif #include "ui_util.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; /* 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; } capture_opts->state = CAPTURE_STOPPED; } return ret; } void capture_stop(capture_options *capture_opts) { /* stop the capture child gracefully */ sync_pipe_stop(capture_opts); } void capture_restart(capture_options *capture_opts) { capture_opts->restart = TRUE; capture_stop(capture_opts); } void capture_kill_child(capture_options *capture_opts) { /* 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_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!", 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; g_assert(capture_opts->state == CAPTURE_PREPARING || capture_opts->state == CAPTURE_RUNNING); /*g_warning("New capture file: %s", new_file);*/ /* 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) */ 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; } 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. XXX - do something if this fails? */ 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); main_window_update(); 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; } } } /* capture child closed it's side ot the pipe, do the required cleanup */ void capture_input_closed(capture_options *capture_opts) { int err; g_assert(capture_opts->state == CAPTURE_PREPARING || capture_opts->state == CAPTURE_RUNNING); /* if we didn't started the capture (happens if an error occured), do a fake start */ 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) { /* first of all, we are not doing a capture any more */ cf_callback_invoke(cf_cb_live_capture_update_finished, capture_opts->cf); /* Read what remains of the capture file, and finish the capture. XXX - do something if this fails? */ switch (cf_finish_tail(capture_opts->cf, &err)) { case CF_READ_OK: if(cf_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!", 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)); } } 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; 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 */