2 * Routines for packet capture windows
4 * $Id: capture.c,v 1.85 1999/11/30 23:56:34 gram Exp $
6 * Ethereal - Network traffic analyzer
7 * By Gerald Combs <gerald@zing.org>
8 * Copyright 1998 Gerald Combs
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version 2
14 * of the License, or (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
33 #ifdef HAVE_SYS_TYPES_H
34 # include <sys/types.h>
37 #ifdef HAVE_SYS_STAT_H
38 # include <sys/stat.h>
41 #ifdef HAVE_SYS_WAIT_H
42 # include <sys/wait.h>
58 #ifdef HAVE_SYS_SOCKET_H
59 #include <sys/socket.h>
62 #ifdef HAVE_SYS_IOCTL_H
63 #include <sys/ioctl.h>
73 #ifdef NEED_SNPRINTF_H
79 # include "snprintf.h"
87 #include "gtk/gtkglobals.h"
96 int sync_mode; /* fork a child to do the capture, and sync between them */
97 static int sync_pipe[2]; /* used to sync father */
98 int quit_after_cap; /* Makes a "capture only mode". Implies -k */
99 gboolean capture_child; /* if this is the child for "-S" */
100 static guint cap_input_id;
102 static void cap_file_input_cb(gpointer, gint, GdkInputCondition);
103 static void capture_stop_cb(GtkWidget *, gpointer);
104 static void capture_pcap_cb(u_char *, const struct pcap_pkthdr *,
106 static float pct(gint, gint);
108 typedef struct _loop_data {
113 packet_counts counts;
117 /* Open a specified file, or create a temporary file, and start a capture
118 to the file in question. */
120 do_capture(char *capfile_name)
123 gboolean is_tempfile;
129 int capture_succeeded;
131 if (capfile_name != NULL) {
132 /* Try to open/create the specified file for use as a capture buffer. */
133 cf.save_file_fd = open(capfile_name, O_RDWR|O_TRUNC|O_CREAT, 0600);
136 /* Choose a random name for the capture buffer */
137 cf.save_file_fd = create_tempfile(tmpname, sizeof tmpname, "ether");
138 capfile_name = g_strdup(tmpname);
141 if (cf.save_file_fd == -1) {
142 simple_dialog(ESD_TYPE_WARN, NULL,
143 "The file to which the capture would be saved (\"%s\")"
144 "could not be opened: %s.", capfile_name, strerror(errno));
147 close_cap_file(&cf, info_bar);
148 g_assert(cf.save_file == NULL);
149 cf.save_file = capfile_name;
151 if (sync_mode) { /* use fork() for capture */
154 char scount[24]; /* need a constant for len of numbers */
155 char save_file_fd[24];
157 sprintf(ssnap,"%d",cf.snap); /* in lieu of itoa */
158 sprintf(scount,"%d",cf.count);
159 sprintf(save_file_fd,"%d",cf.save_file_fd);
160 signal(SIGCHLD, SIG_IGN);
162 if ((fork_child = fork()) == 0) {
164 * Child process - run Ethereal with the right arguments to make
165 * it just pop up the live capture dialog box and capture with
166 * the specified capture parameters, writing to the specified file.
168 * args: -i interface specification
170 * -W file descriptor to write
171 * -c count to capture
174 * -f "filter expression"
179 execlp(ethereal_path, CHILD_NAME, "-i", cf.iface,
180 "-w", cf.save_file, "-W", save_file_fd,
181 "-c", scount, "-s", ssnap,
182 "-m", medium_font, "-b", bold_font,
183 (cf.cfilter == NULL)? 0 : "-f",
184 (cf.cfilter == NULL)? 0 : cf.cfilter,
187 /* Parent process - read messages from the child process over the
191 /* Read a byte count from "sync_pipe[0]", terminated with a
192 colon; if the count is 0, the child process created the
193 capture file and we should start reading from it, otherwise
194 the capture couldn't start and the count is a count of bytes
195 of error message, and we should display the message. */
198 i = read(sync_pipe[0], &c, 1);
200 /* EOF - the child process died.
201 Close the read side of the sync pipe, remove the capture file,
202 and report the failure.
203 XXX - reap the child process and report the status in detail. */
205 unlink(cf.save_file);
206 g_free(cf.save_file);
208 simple_dialog(ESD_TYPE_WARN, NULL, "Capture child process died");
214 /* Child process handed us crap.
215 Close the read side of the sync pipe, remove the capture file,
216 and report the failure. */
218 unlink(cf.save_file);
219 g_free(cf.save_file);
221 simple_dialog(ESD_TYPE_WARN, NULL,
222 "Capture child process sent us a bad message");
225 byte_count = byte_count*10 + c - '0';
227 if (byte_count == 0) {
228 /* Success. Open the capture file, and set up to read it. */
229 err = start_tail_cap_file(cf.save_file, is_tempfile, &cf);
231 /* We were able to open and set up to read the capture file;
232 arrange that our callback be called whenever it's possible
233 to read from the sync pipe, so that it's called when
234 the child process wants to tell us something. */
235 cap_input_id = gtk_input_add_full(sync_pipe[0],
242 /* We weren't able to open the capture file; complain, and
243 close the sync pipe. */
244 simple_dialog(ESD_TYPE_WARN, NULL,
245 file_open_error_message(err, FALSE), cf.save_file);
247 /* Close the sync pipe. */
250 /* Don't unlink the save file - leave it around, for debugging
252 g_free(cf.save_file);
256 /* Failure - the child process sent us a message indicating
257 what the problem was. */
258 msg = g_malloc(byte_count + 1);
260 simple_dialog(ESD_TYPE_WARN, NULL,
261 "Capture child process failed, but its error message was too big.");
263 i = read(sync_pipe[0], msg, byte_count);
265 simple_dialog(ESD_TYPE_WARN, NULL,
266 "Capture child process failed: Error %s reading its error message.",
269 simple_dialog(ESD_TYPE_WARN, NULL,
270 "Capture child process failed: EOF reading its error message.");
272 simple_dialog(ESD_TYPE_WARN, NULL, msg);
275 /* Close the sync pipe. */
278 /* Get rid of the save file - the capture never started. */
279 unlink(cf.save_file);
280 g_free(cf.save_file);
287 capture_succeeded = capture();
288 if (quit_after_cap) {
289 /* DON'T unlink the save file. Presumably someone wants it. */
292 if (capture_succeeded) {
293 /* Capture succeeded; read in the capture file. */
294 if ((err = open_cap_file(cf.save_file, is_tempfile, &cf)) == 0) {
295 /* Set the read filter to NULL. */
297 err = read_cap_file(&cf);
300 /* We're not doing a capture any more, so we don't have a save
302 g_free(cf.save_file);
307 /* There's stuff to read from the sync pipe, meaning the child has sent
308 us a message, or the sync pipe has closed, meaning the child has
309 closed it (perhaps because it exited). */
311 cap_file_input_cb(gpointer data, gint source, GdkInputCondition condition)
313 capture_file *cf = (capture_file *)data;
314 char buffer[256+1], *p = buffer, *q = buffer;
317 gboolean exit_loop = FALSE;
323 char sigmsg_buf[6+1+3+1];
326 /* avoid reentrancy problems and stack overflow */
327 gtk_input_remove(cap_input_id);
329 if ((nread = read(sync_pipe[0], buffer, 256)) <= 0) {
330 /* The child has closed the sync pipe, meaning it's not going to be
331 capturing any more packets. Pick up its exit status, and
332 complain if it died of a signal. */
333 if (wait(&wstatus) != -1) {
334 /* XXX - are there any platforms on which we can run that *don't*
335 support POSIX.1's <sys/wait.h> and macros therein? */
336 wsignal = wstatus & 0177;
338 if (wstatus == 0177) {
339 /* It stopped, rather than exiting. "Should not happen." */
341 wsignal = (wstatus >> 8) & 0xFF;
345 coredumped = " - core dumped";
355 sigmsg = "Interrupted";
363 sigmsg = "Illegal instruction";
367 sigmsg = "Trace trap";
375 sigmsg = "Arithmetic exception";
383 sigmsg = "Bus error";
387 sigmsg = "Segmentation violation";
390 /* http://metalab.unc.edu/pub/Linux/docs/HOWTO/GCC-HOWTO
391 Linux is POSIX compliant. These are not POSIX-defined signals ---
392 ISO/IEC 9945-1:1990 (IEEE Std 1003.1-1990), paragraph B.3.3.1.1 sez:
394 ``The signals SIGBUS, SIGEMT, SIGIOT, SIGTRAP, and SIGSYS
395 were omitted from POSIX.1 because their behavior is
396 implementation dependent and could not be adequately catego-
397 rized. Conforming implementations may deliver these sig-
398 nals, but must document the circumstances under which they
399 are delivered and note any restrictions concerning their
405 sigmsg = "Bad system call";
410 sigmsg = "Broken pipe";
414 sigmsg = "Alarm clock";
418 sigmsg = "Terminated";
422 sprintf(sigmsg_buf, "Signal %d", wsignal);
426 simple_dialog(ESD_TYPE_WARN, NULL,
427 "Child capture process %s: %s%s", msg, sigmsg, coredumped);
431 /* Read what remains of the capture file, and finish the capture.
432 XXX - do something if this fails? */
433 err = finish_tail_cap_file(cf);
435 /* We're not doing a capture any more, so we don't have a save
437 g_free(cf->save_file);
438 cf->save_file = NULL;
443 buffer[nread] = '\0';
446 /* look for (possibly multiple) '*' */
454 /* XXX should handle the case of a pipe full (i.e. no star found) */
463 /* Read from the capture file the number of records the child told us
465 XXX - do something if this fails? */
466 err = continue_tail_cap_file(cf, to_read);
468 /* restore pipe handler */
469 cap_input_id = gtk_input_add_full (sync_pipe[0],
477 /* Do the low-level work of a capture.
478 Returns TRUE if it succeeds, FALSE otherwise. */
482 GtkWidget *cap_w, *main_vb, *count_lb, *tcp_lb, *udp_lb, *icmp_lb,
483 *ospf_lb, *gre_lb, *netbios_lb, *ipx_lb, *other_lb, *stop_bt;
485 gchar err_str[PCAP_ERRBUF_SIZE], label_str[32];
487 bpf_u_int32 netnum, netmask;
488 time_t upd_time, cur_time;
495 ld.linktype = WTAP_ENCAP_UNKNOWN;
503 ld.counts.netbios = 0;
507 /* Open the network interface to capture from it. */
508 pch = pcap_open_live(cf.iface, cf.snap, 1, 250, err_str);
511 /* Well, we couldn't start the capture.
512 If this is a child process that does the capturing in sync
513 mode or fork mode, it shouldn't do any UI stuff until we pop up the
514 capture-progress window, and, since we couldn't start the
515 capture, we haven't popped it up. */
516 if (!capture_child) {
517 while (gtk_events_pending()) gtk_main_iteration();
519 snprintf(errmsg, sizeof errmsg,
520 "The capture session could not be initiated (%s).\n"
521 "Please check to make sure you have sufficient permissions, and that\n"
522 "you have the proper interface specified.", err_str);
527 /* A capture filter was specified; set it up. */
528 if (pcap_lookupnet (cf.iface, &netnum, &netmask, err_str) < 0) {
529 snprintf(errmsg, sizeof errmsg,
530 "Can't use filter: Couldn't obtain netmask info (%s).", err_str);
533 if (pcap_compile(pch, &cf.fcode, cf.cfilter, 1, netmask) < 0) {
534 snprintf(errmsg, sizeof errmsg, "Unable to parse filter string (%s).",
538 if (pcap_setfilter(pch, &cf.fcode) < 0) {
539 snprintf(errmsg, sizeof errmsg, "Can't install filter (%s).",
545 /* Set up to write to the capture file. */
546 ld.linktype = wtap_pcap_encap_to_wtap_encap(pcap_datalink(pch));
547 if (ld.linktype == WTAP_ENCAP_UNKNOWN) {
548 strcpy(errmsg, "The network you're capturing from is of a type"
549 " that Ethereal doesn't support.");
552 ld.pdh = wtap_dump_fdopen(cf.save_file_fd, WTAP_FILE_PCAP,
553 ld.linktype, pcap_snapshot(pch), &err);
555 if (ld.pdh == NULL) {
556 /* We couldn't set up to write to the capture file. */
559 case WTAP_ERR_CANT_OPEN:
560 strcpy(errmsg, "The file to which the capture would be saved"
561 " couldn't be created for some unknown reason.");
564 case WTAP_ERR_SHORT_WRITE:
565 strcpy(errmsg, "A full header couldn't be written to the file"
566 " to which the capture would be saved.");
571 sprintf(errmsg, "The file to which the capture would be"
572 " saved (\"%s\") could not be opened: Error %d.",
575 sprintf(errmsg, "The file to which the capture would be"
576 " saved (\"%s\") could not be opened: %s.",
577 cf.save_file, strerror(err));
585 /* Well, we should be able to start capturing.
587 This is the child process for a sync mode capture, so sync out
588 the capture file, so the header makes it to the file system,
589 and send a "capture started successfully and capture file created"
590 message to our parent so that they'll open the capture file and
591 update its windows to indicate that we have a live capture in
593 fflush(wtap_dump_file(ld.pdh));
597 cap_w = gtk_window_new(GTK_WINDOW_TOPLEVEL);
598 gtk_window_set_title(GTK_WINDOW(cap_w), "Ethereal: Capture / Playback");
600 /* Container for capture display widgets */
601 main_vb = gtk_vbox_new(FALSE, 1);
602 gtk_container_border_width(GTK_CONTAINER(main_vb), 5);
603 gtk_container_add(GTK_CONTAINER(cap_w), main_vb);
604 gtk_widget_show(main_vb);
606 count_lb = gtk_label_new("Count: 0");
607 gtk_box_pack_start(GTK_BOX(main_vb), count_lb, FALSE, FALSE, 3);
608 gtk_widget_show(count_lb);
610 tcp_lb = gtk_label_new("TCP: 0 (0.0%)");
611 gtk_box_pack_start(GTK_BOX(main_vb), tcp_lb, FALSE, FALSE, 3);
612 gtk_widget_show(tcp_lb);
614 udp_lb = gtk_label_new("UDP: 0 (0.0%)");
615 gtk_box_pack_start(GTK_BOX(main_vb), udp_lb, FALSE, FALSE, 3);
616 gtk_widget_show(udp_lb);
618 icmp_lb = gtk_label_new("ICMP: 0 (0.0%)");
619 gtk_box_pack_start(GTK_BOX(main_vb), icmp_lb, FALSE, FALSE, 3);
620 gtk_widget_show(icmp_lb);
622 ospf_lb = gtk_label_new("OSPF: 0 (0.0%)");
623 gtk_box_pack_start(GTK_BOX(main_vb), ospf_lb, FALSE, FALSE, 3);
624 gtk_widget_show(ospf_lb);
626 gre_lb = gtk_label_new("GRE: 0 (0.0%)");
627 gtk_box_pack_start(GTK_BOX(main_vb), gre_lb, FALSE, FALSE, 3);
628 gtk_widget_show(gre_lb);
630 netbios_lb = gtk_label_new("NetBIOS: 0 (0.0%)");
631 gtk_box_pack_start(GTK_BOX(main_vb), netbios_lb, FALSE, FALSE, 3);
632 gtk_widget_show(netbios_lb);
634 ipx_lb = gtk_label_new("IPX: 0 (0.0%)");
635 gtk_box_pack_start(GTK_BOX(main_vb), ipx_lb, FALSE, FALSE, 3);
636 gtk_widget_show(ipx_lb);
638 other_lb = gtk_label_new("Other: 0 (0.0%)");
639 gtk_box_pack_start(GTK_BOX(main_vb), other_lb, FALSE, FALSE, 3);
640 gtk_widget_show(other_lb);
642 stop_bt = gtk_button_new_with_label ("Stop");
643 gtk_signal_connect(GTK_OBJECT(stop_bt), "clicked",
644 GTK_SIGNAL_FUNC(capture_stop_cb), (gpointer) &ld);
645 gtk_box_pack_end(GTK_BOX(main_vb), stop_bt, FALSE, FALSE, 3);
646 GTK_WIDGET_SET_FLAGS(stop_bt, GTK_CAN_DEFAULT);
647 gtk_widget_grab_default(stop_bt);
648 GTK_WIDGET_SET_FLAGS(stop_bt, GTK_CAN_DEFAULT);
649 gtk_widget_grab_default(stop_bt);
650 gtk_widget_show(stop_bt);
652 gtk_widget_show(cap_w);
655 upd_time = time(NULL);
657 while (gtk_events_pending()) gtk_main_iteration();
658 inpkts = pcap_dispatch(pch, 1, capture_pcap_cb, (u_char *) &ld);
660 ld.sync_packets += inpkts;
661 /* Only update once a second so as not to overload slow displays */
662 cur_time = time(NULL);
663 if (cur_time > upd_time) {
666 sprintf(label_str, "Count: %d", ld.counts.total);
667 gtk_label_set(GTK_LABEL(count_lb), label_str);
669 sprintf(label_str, "TCP: %d (%.1f%%)", ld.counts.tcp,
670 pct(ld.counts.tcp, ld.counts.total));
671 gtk_label_set(GTK_LABEL(tcp_lb), label_str);
673 sprintf(label_str, "UDP: %d (%.1f%%)", ld.counts.udp,
674 pct(ld.counts.udp, ld.counts.total));
675 gtk_label_set(GTK_LABEL(udp_lb), label_str);
677 sprintf(label_str, "ICMP: %d (%.1f%%)", ld.counts.icmp,
678 pct(ld.counts.icmp, ld.counts.total));
679 gtk_label_set(GTK_LABEL(icmp_lb), label_str);
681 sprintf(label_str, "OSPF: %d (%.1f%%)", ld.counts.ospf,
682 pct(ld.counts.ospf, ld.counts.total));
683 gtk_label_set(GTK_LABEL(ospf_lb), label_str);
685 sprintf(label_str, "GRE: %d (%.1f%%)", ld.counts.gre,
686 pct(ld.counts.gre, ld.counts.total));
687 gtk_label_set(GTK_LABEL(gre_lb), label_str);
689 sprintf(label_str, "NetBIOS: %d (%.1f%%)", ld.counts.netbios,
690 pct(ld.counts.netbios, ld.counts.total));
691 gtk_label_set(GTK_LABEL(netbios_lb), label_str);
693 sprintf(label_str, "IPX: %d (%.1f%%)", ld.counts.ipx,
694 pct(ld.counts.ipx, ld.counts.total));
695 gtk_label_set(GTK_LABEL(ipx_lb), label_str);
697 sprintf(label_str, "Other: %d (%.1f%%)", ld.counts.other,
698 pct(ld.counts.other, ld.counts.total));
699 gtk_label_set(GTK_LABEL(other_lb), label_str);
701 /* do sync here, too */
702 fflush(wtap_dump_file(ld.pdh));
703 if (capture_child && ld.sync_packets) {
704 /* This is the child process for a sync mode capture, so send
705 our parent a message saying we've written out "ld.sync_packets"
706 packets to the capture file. */
708 sprintf(tmp, "%d*", ld.sync_packets);
709 write(1, tmp, strlen(tmp));
715 if (!wtap_dump_close(ld.pdh, &err)) {
716 /* XXX - in fork mode, this may not pop up, or, if it does,
717 it may disappear as soon as we exit.
719 We should have the parent process, while it's reading
720 the packet count update messages, catch error messages
721 and pop up a message box if it sees one. */
724 case WTAP_ERR_CANT_CLOSE:
725 simple_dialog(ESD_TYPE_WARN, NULL,
726 "The file to which the capture was being saved"
727 " couldn't be closed for some unknown reason.");
730 case WTAP_ERR_SHORT_WRITE:
731 simple_dialog(ESD_TYPE_WARN, NULL,
732 "Not all the data could be written to the file"
733 " to which the capture was being saved.");
737 simple_dialog(ESD_TYPE_WARN, NULL,
738 "The file to which the capture was being"
739 " saved (\"%s\") could not be closed: %s.",
740 cf.save_file, wtap_strerror(err));
746 gtk_grab_remove(GTK_WIDGET(cap_w));
747 gtk_widget_destroy(GTK_WIDGET(cap_w));
752 /* We couldn't even start the capture, so get rid of the capture
754 unlink(cf.save_file); /* silently ignore error */
755 g_free(cf.save_file);
758 /* This is the child process for a sync mode capture.
759 Send the error message to our parent, so they can display a
760 dialog box containing it. */
761 int msglen = strlen(errmsg);
763 sprintf(lenbuf, "%u;", msglen);
764 write(1, lenbuf, strlen(lenbuf));
765 write(1, errmsg, msglen);
767 /* Display the dialog box ourselves; there's no parent. */
768 simple_dialog(ESD_TYPE_WARN, NULL, errmsg);
777 pct(gint num, gint denom) {
779 return (float) num * 100.0 / (float) denom;
786 capture_stop_cb(GtkWidget *w, gpointer data) {
787 loop_data *ld = (loop_data *) data;
793 capture_pcap_cb(u_char *user, const struct pcap_pkthdr *phdr,
795 struct wtap_pkthdr whdr;
796 loop_data *ld = (loop_data *) user;
799 if ((++ld->counts.total >= ld->max) && (ld->max > 0))
805 whdr.caplen = phdr->caplen;
806 whdr.len = phdr->len;
807 whdr.pkt_encap = ld->linktype;
809 /* XXX - do something if this fails */
810 wtap_dump(ld->pdh, &whdr, pd, &err);
813 switch (ld->linktype) {
814 case WTAP_ENCAP_ETHERNET:
815 capture_eth(pd, phdr->caplen, &ld->counts);
817 case WTAP_ENCAP_FDDI:
818 case WTAP_ENCAP_FDDI_BITSWAPPED:
819 capture_fddi(pd, phdr->caplen, &ld->counts);
822 capture_tr(pd, phdr->caplen, &ld->counts);
824 case WTAP_ENCAP_NULL:
825 capture_null(pd, phdr->caplen, &ld->counts);
828 capture_ppp(pd, phdr->caplen, &ld->counts);
830 case WTAP_ENCAP_RAW_IP:
831 capture_raw(pd, phdr->caplen, &ld->counts);
833 /* XXX - FreeBSD may append 4-byte ATM pseudo-header to DLT_ATM_RFC1483,
834 with LLC header following; we should implement it at some
839 #endif /* HAVE_LIBPCAP */