2 * Routines for packet capture windows
4 * $Id: capture.c,v 1.84 1999/11/30 20:49:45 guy 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, *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;
502 ld.counts.netbios = 0;
506 /* Open the network interface to capture from it. */
507 pch = pcap_open_live(cf.iface, cf.snap, 1, 250, err_str);
510 /* Well, we couldn't start the capture.
511 If this is a child process that does the capturing in sync
512 mode or fork mode, it shouldn't do any UI stuff until we pop up the
513 capture-progress window, and, since we couldn't start the
514 capture, we haven't popped it up. */
515 if (!capture_child) {
516 while (gtk_events_pending()) gtk_main_iteration();
518 snprintf(errmsg, sizeof errmsg,
519 "The capture session could not be initiated (%s).\n"
520 "Please check to make sure you have sufficient permissions, and that\n"
521 "you have the proper interface specified.", err_str);
526 /* A capture filter was specified; set it up. */
527 if (pcap_lookupnet (cf.iface, &netnum, &netmask, err_str) < 0) {
528 snprintf(errmsg, sizeof errmsg,
529 "Can't use filter: Couldn't obtain netmask info (%s).", err_str);
532 if (pcap_compile(pch, &cf.fcode, cf.cfilter, 1, netmask) < 0) {
533 snprintf(errmsg, sizeof errmsg, "Unable to parse filter string (%s).",
537 if (pcap_setfilter(pch, &cf.fcode) < 0) {
538 snprintf(errmsg, sizeof errmsg, "Can't install filter (%s).",
544 /* Set up to write to the capture file. */
545 ld.linktype = wtap_pcap_encap_to_wtap_encap(pcap_datalink(pch));
546 if (ld.linktype == WTAP_ENCAP_UNKNOWN) {
547 strcpy(errmsg, "The network you're capturing from is of a type"
548 " that Ethereal doesn't support.");
551 ld.pdh = wtap_dump_fdopen(cf.save_file_fd, WTAP_FILE_PCAP,
552 ld.linktype, pcap_snapshot(pch), &err);
554 if (ld.pdh == NULL) {
555 /* We couldn't set up to write to the capture file. */
558 case WTAP_ERR_CANT_OPEN:
559 strcpy(errmsg, "The file to which the capture would be saved"
560 " couldn't be created for some unknown reason.");
563 case WTAP_ERR_SHORT_WRITE:
564 strcpy(errmsg, "A full header couldn't be written to the file"
565 " to which the capture would be saved.");
570 sprintf(errmsg, "The file to which the capture would be"
571 " saved (\"%s\") could not be opened: Error %d.",
574 sprintf(errmsg, "The file to which the capture would be"
575 " saved (\"%s\") could not be opened: %s.",
576 cf.save_file, strerror(err));
584 /* Well, we should be able to start capturing.
586 This is the child process for a sync mode capture, so sync out
587 the capture file, so the header makes it to the file system,
588 and send a "capture started successfully and capture file created"
589 message to our parent so that they'll open the capture file and
590 update its windows to indicate that we have a live capture in
592 fflush(wtap_dump_file(ld.pdh));
596 cap_w = gtk_window_new(GTK_WINDOW_TOPLEVEL);
597 gtk_window_set_title(GTK_WINDOW(cap_w), "Ethereal: Capture / Playback");
599 /* Container for capture display widgets */
600 main_vb = gtk_vbox_new(FALSE, 1);
601 gtk_container_border_width(GTK_CONTAINER(main_vb), 5);
602 gtk_container_add(GTK_CONTAINER(cap_w), main_vb);
603 gtk_widget_show(main_vb);
605 count_lb = gtk_label_new("Count: 0");
606 gtk_box_pack_start(GTK_BOX(main_vb), count_lb, FALSE, FALSE, 3);
607 gtk_widget_show(count_lb);
609 tcp_lb = gtk_label_new("TCP: 0 (0.0%)");
610 gtk_box_pack_start(GTK_BOX(main_vb), tcp_lb, FALSE, FALSE, 3);
611 gtk_widget_show(tcp_lb);
613 udp_lb = gtk_label_new("UDP: 0 (0.0%)");
614 gtk_box_pack_start(GTK_BOX(main_vb), udp_lb, FALSE, FALSE, 3);
615 gtk_widget_show(udp_lb);
617 icmp_lb = gtk_label_new("ICMP: 0 (0.0%)");
618 gtk_box_pack_start(GTK_BOX(main_vb), icmp_lb, FALSE, FALSE, 3);
619 gtk_widget_show(icmp_lb);
621 ospf_lb = gtk_label_new("OSPF: 0 (0.0%)");
622 gtk_box_pack_start(GTK_BOX(main_vb), ospf_lb, FALSE, FALSE, 3);
623 gtk_widget_show(ospf_lb);
625 gre_lb = gtk_label_new("GRE: 0 (0.0%)");
626 gtk_box_pack_start(GTK_BOX(main_vb), gre_lb, FALSE, FALSE, 3);
627 gtk_widget_show(gre_lb);
629 netbios_lb = gtk_label_new("NetBIOS: 0 (0.0%)");
630 gtk_box_pack_start(GTK_BOX(main_vb), netbios_lb, FALSE, FALSE, 3);
631 gtk_widget_show(netbios_lb);
633 other_lb = gtk_label_new("Other: 0 (0.0%)");
634 gtk_box_pack_start(GTK_BOX(main_vb), other_lb, FALSE, FALSE, 3);
635 gtk_widget_show(other_lb);
637 stop_bt = gtk_button_new_with_label ("Stop");
638 gtk_signal_connect(GTK_OBJECT(stop_bt), "clicked",
639 GTK_SIGNAL_FUNC(capture_stop_cb), (gpointer) &ld);
640 gtk_box_pack_end(GTK_BOX(main_vb), stop_bt, FALSE, FALSE, 3);
641 GTK_WIDGET_SET_FLAGS(stop_bt, GTK_CAN_DEFAULT);
642 gtk_widget_grab_default(stop_bt);
643 GTK_WIDGET_SET_FLAGS(stop_bt, GTK_CAN_DEFAULT);
644 gtk_widget_grab_default(stop_bt);
645 gtk_widget_show(stop_bt);
647 gtk_widget_show(cap_w);
650 upd_time = time(NULL);
652 while (gtk_events_pending()) gtk_main_iteration();
653 inpkts = pcap_dispatch(pch, 1, capture_pcap_cb, (u_char *) &ld);
655 ld.sync_packets += inpkts;
656 /* Only update once a second so as not to overload slow displays */
657 cur_time = time(NULL);
658 if (cur_time > upd_time) {
661 sprintf(label_str, "Count: %d", ld.counts.total);
662 gtk_label_set(GTK_LABEL(count_lb), label_str);
664 sprintf(label_str, "TCP: %d (%.1f%%)", ld.counts.tcp,
665 pct(ld.counts.tcp, ld.counts.total));
666 gtk_label_set(GTK_LABEL(tcp_lb), label_str);
668 sprintf(label_str, "UDP: %d (%.1f%%)", ld.counts.udp,
669 pct(ld.counts.udp, ld.counts.total));
670 gtk_label_set(GTK_LABEL(udp_lb), label_str);
672 sprintf(label_str, "ICMP: %d (%.1f%%)", ld.counts.icmp,
673 pct(ld.counts.icmp, ld.counts.total));
674 gtk_label_set(GTK_LABEL(icmp_lb), label_str);
676 sprintf(label_str, "OSPF: %d (%.1f%%)", ld.counts.ospf,
677 pct(ld.counts.ospf, ld.counts.total));
678 gtk_label_set(GTK_LABEL(ospf_lb), label_str);
680 sprintf(label_str, "GRE: %d (%.1f%%)", ld.counts.gre,
681 pct(ld.counts.gre, ld.counts.total));
682 gtk_label_set(GTK_LABEL(gre_lb), label_str);
684 sprintf(label_str, "NetBIOS: %d (%.1f%%)", ld.counts.netbios,
685 pct(ld.counts.netbios, ld.counts.total));
686 gtk_label_set(GTK_LABEL(netbios_lb), label_str);
688 sprintf(label_str, "Other: %d (%.1f%%)", ld.counts.other,
689 pct(ld.counts.other, ld.counts.total));
690 gtk_label_set(GTK_LABEL(other_lb), label_str);
692 /* do sync here, too */
693 fflush(wtap_dump_file(ld.pdh));
694 if (capture_child && ld.sync_packets) {
695 /* This is the child process for a sync mode capture, so send
696 our parent a message saying we've written out "ld.sync_packets"
697 packets to the capture file. */
699 sprintf(tmp, "%d*", ld.sync_packets);
700 write(1, tmp, strlen(tmp));
706 if (!wtap_dump_close(ld.pdh, &err)) {
707 /* XXX - in fork mode, this may not pop up, or, if it does,
708 it may disappear as soon as we exit.
710 We should have the parent process, while it's reading
711 the packet count update messages, catch error messages
712 and pop up a message box if it sees one. */
715 case WTAP_ERR_CANT_CLOSE:
716 simple_dialog(ESD_TYPE_WARN, NULL,
717 "The file to which the capture was being saved"
718 " couldn't be closed for some unknown reason.");
721 case WTAP_ERR_SHORT_WRITE:
722 simple_dialog(ESD_TYPE_WARN, NULL,
723 "Not all the data could be written to the file"
724 " to which the capture was being saved.");
728 simple_dialog(ESD_TYPE_WARN, NULL,
729 "The file to which the capture was being"
730 " saved (\"%s\") could not be closed: %s.",
731 cf.save_file, wtap_strerror(err));
737 gtk_grab_remove(GTK_WIDGET(cap_w));
738 gtk_widget_destroy(GTK_WIDGET(cap_w));
743 /* We couldn't even start the capture, so get rid of the capture
745 unlink(cf.save_file); /* silently ignore error */
746 g_free(cf.save_file);
749 /* This is the child process for a sync mode capture.
750 Send the error message to our parent, so they can display a
751 dialog box containing it. */
752 int msglen = strlen(errmsg);
754 sprintf(lenbuf, "%u;", msglen);
755 write(1, lenbuf, strlen(lenbuf));
756 write(1, errmsg, msglen);
758 /* Display the dialog box ourselves; there's no parent. */
759 simple_dialog(ESD_TYPE_WARN, NULL, errmsg);
768 pct(gint num, gint denom) {
770 return (float) num * 100.0 / (float) denom;
777 capture_stop_cb(GtkWidget *w, gpointer data) {
778 loop_data *ld = (loop_data *) data;
784 capture_pcap_cb(u_char *user, const struct pcap_pkthdr *phdr,
786 struct wtap_pkthdr whdr;
787 loop_data *ld = (loop_data *) user;
790 if ((++ld->counts.total >= ld->max) && (ld->max > 0))
796 whdr.caplen = phdr->caplen;
797 whdr.len = phdr->len;
798 whdr.pkt_encap = ld->linktype;
800 /* XXX - do something if this fails */
801 wtap_dump(ld->pdh, &whdr, pd, &err);
804 switch (ld->linktype) {
805 case WTAP_ENCAP_ETHERNET:
806 capture_eth(pd, phdr->caplen, &ld->counts);
808 case WTAP_ENCAP_FDDI:
809 case WTAP_ENCAP_FDDI_BITSWAPPED:
810 capture_fddi(pd, phdr->caplen, &ld->counts);
813 capture_tr(pd, phdr->caplen, &ld->counts);
815 case WTAP_ENCAP_NULL:
816 capture_null(pd, phdr->caplen, &ld->counts);
819 capture_ppp(pd, phdr->caplen, &ld->counts);
821 case WTAP_ENCAP_RAW_IP:
822 capture_raw(pd, phdr->caplen, &ld->counts);
824 /* XXX - FreeBSD may append 4-byte ATM pseudo-header to DLT_ATM_RFC1483,
825 with LLC header following; we should implement it at some
830 #endif /* HAVE_LIBPCAP */