2 * Routines for packet capture windows
4 * $Id: capture.c,v 1.89 2000/01/12 06:56:32 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"
92 #include "simple_dialog.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],
478 * Timeout, in milliseconds, for reads from the stream of captured packets.
480 #define CAP_READ_TIMEOUT 250
482 /* Do the low-level work of a capture.
483 Returns TRUE if it succeeds, FALSE otherwise. */
487 GtkWidget *cap_w, *main_vb, *count_lb, *tcp_lb, *udp_lb, *icmp_lb,
488 *ospf_lb, *gre_lb, *netbios_lb, *ipx_lb, *other_lb, *stop_bt;
490 gchar err_str[PCAP_ERRBUF_SIZE], label_str[32];
492 bpf_u_int32 netnum, netmask;
493 time_t upd_time, cur_time;
498 struct timeval timeout;
505 ld.linktype = WTAP_ENCAP_UNKNOWN;
513 ld.counts.netbios = 0;
517 /* Open the network interface to capture from it. */
518 pch = pcap_open_live(cf.iface, cf.snap, 1, CAP_READ_TIMEOUT, err_str);
521 /* Well, we couldn't start the capture.
522 If this is a child process that does the capturing in sync
523 mode or fork mode, it shouldn't do any UI stuff until we pop up the
524 capture-progress window, and, since we couldn't start the
525 capture, we haven't popped it up. */
526 if (!capture_child) {
527 while (gtk_events_pending()) gtk_main_iteration();
529 snprintf(errmsg, sizeof errmsg,
530 "The capture session could not be initiated (%s).\n"
531 "Please check to make sure you have sufficient permissions, and that\n"
532 "you have the proper interface specified.", err_str);
537 /* A capture filter was specified; set it up. */
538 if (pcap_lookupnet (cf.iface, &netnum, &netmask, err_str) < 0) {
539 snprintf(errmsg, sizeof errmsg,
540 "Can't use filter: Couldn't obtain netmask info (%s).", err_str);
543 if (pcap_compile(pch, &cf.fcode, cf.cfilter, 1, netmask) < 0) {
544 snprintf(errmsg, sizeof errmsg, "Unable to parse filter string (%s).",
548 if (pcap_setfilter(pch, &cf.fcode) < 0) {
549 snprintf(errmsg, sizeof errmsg, "Can't install filter (%s).",
555 /* Set up to write to the capture file. */
556 ld.linktype = wtap_pcap_encap_to_wtap_encap(pcap_datalink(pch));
557 if (ld.linktype == WTAP_ENCAP_UNKNOWN) {
558 strcpy(errmsg, "The network you're capturing from is of a type"
559 " that Ethereal doesn't support.");
562 ld.pdh = wtap_dump_fdopen(cf.save_file_fd, WTAP_FILE_PCAP,
563 ld.linktype, pcap_snapshot(pch), &err);
565 if (ld.pdh == NULL) {
566 /* We couldn't set up to write to the capture file. */
569 case WTAP_ERR_CANT_OPEN:
570 strcpy(errmsg, "The file to which the capture would be saved"
571 " couldn't be created for some unknown reason.");
574 case WTAP_ERR_SHORT_WRITE:
575 strcpy(errmsg, "A full header couldn't be written to the file"
576 " to which the capture would be saved.");
581 sprintf(errmsg, "The file to which the capture would be"
582 " saved (\"%s\") could not be opened: Error %d.",
585 sprintf(errmsg, "The file to which the capture would be"
586 " saved (\"%s\") could not be opened: %s.",
587 cf.save_file, strerror(err));
595 /* Well, we should be able to start capturing.
597 This is the child process for a sync mode capture, so sync out
598 the capture file, so the header makes it to the file system,
599 and send a "capture started successfully and capture file created"
600 message to our parent so that they'll open the capture file and
601 update its windows to indicate that we have a live capture in
603 fflush(wtap_dump_file(ld.pdh));
607 cap_w = gtk_window_new(GTK_WINDOW_TOPLEVEL);
608 gtk_window_set_title(GTK_WINDOW(cap_w), "Ethereal: Capture / Playback");
610 /* Container for capture display widgets */
611 main_vb = gtk_vbox_new(FALSE, 1);
612 gtk_container_border_width(GTK_CONTAINER(main_vb), 5);
613 gtk_container_add(GTK_CONTAINER(cap_w), main_vb);
614 gtk_widget_show(main_vb);
616 count_lb = gtk_label_new("Count: 0");
617 gtk_box_pack_start(GTK_BOX(main_vb), count_lb, FALSE, FALSE, 3);
618 gtk_widget_show(count_lb);
620 tcp_lb = gtk_label_new("TCP: 0 (0.0%)");
621 gtk_box_pack_start(GTK_BOX(main_vb), tcp_lb, FALSE, FALSE, 3);
622 gtk_widget_show(tcp_lb);
624 udp_lb = gtk_label_new("UDP: 0 (0.0%)");
625 gtk_box_pack_start(GTK_BOX(main_vb), udp_lb, FALSE, FALSE, 3);
626 gtk_widget_show(udp_lb);
628 icmp_lb = gtk_label_new("ICMP: 0 (0.0%)");
629 gtk_box_pack_start(GTK_BOX(main_vb), icmp_lb, FALSE, FALSE, 3);
630 gtk_widget_show(icmp_lb);
632 ospf_lb = gtk_label_new("OSPF: 0 (0.0%)");
633 gtk_box_pack_start(GTK_BOX(main_vb), ospf_lb, FALSE, FALSE, 3);
634 gtk_widget_show(ospf_lb);
636 gre_lb = gtk_label_new("GRE: 0 (0.0%)");
637 gtk_box_pack_start(GTK_BOX(main_vb), gre_lb, FALSE, FALSE, 3);
638 gtk_widget_show(gre_lb);
640 netbios_lb = gtk_label_new("NetBIOS: 0 (0.0%)");
641 gtk_box_pack_start(GTK_BOX(main_vb), netbios_lb, FALSE, FALSE, 3);
642 gtk_widget_show(netbios_lb);
644 ipx_lb = gtk_label_new("IPX: 0 (0.0%)");
645 gtk_box_pack_start(GTK_BOX(main_vb), ipx_lb, FALSE, FALSE, 3);
646 gtk_widget_show(ipx_lb);
648 other_lb = gtk_label_new("Other: 0 (0.0%)");
649 gtk_box_pack_start(GTK_BOX(main_vb), other_lb, FALSE, FALSE, 3);
650 gtk_widget_show(other_lb);
652 stop_bt = gtk_button_new_with_label ("Stop");
653 gtk_signal_connect(GTK_OBJECT(stop_bt), "clicked",
654 GTK_SIGNAL_FUNC(capture_stop_cb), (gpointer) &ld);
655 gtk_box_pack_end(GTK_BOX(main_vb), stop_bt, FALSE, FALSE, 3);
656 GTK_WIDGET_SET_FLAGS(stop_bt, GTK_CAN_DEFAULT);
657 gtk_widget_grab_default(stop_bt);
658 GTK_WIDGET_SET_FLAGS(stop_bt, GTK_CAN_DEFAULT);
659 gtk_widget_grab_default(stop_bt);
660 gtk_widget_show(stop_bt);
662 gtk_widget_show(cap_w);
665 upd_time = time(NULL);
667 pcap_fd = pcap_fileno(pch);
670 while (gtk_events_pending()) gtk_main_iteration();
673 * Sigh. The semantics of the read timeout argument to
674 * "pcap_open_live()" aren't particularly well specified by
675 * the "pcap" man page - at least with the BSD BPF code, the
676 * intent appears to be, at least in part, a way of cutting
677 * down the number of reads done on a capture, by blocking
678 * until the buffer fills or a timer expires - and the Linux
679 * libpcap doesn't actually support it, so we can't use it
680 * to break out of the "pcap_dispatch()" every 1/4 of a second
683 * Thus, on Linux, we do a "select()" on the file descriptor for the
684 * capture, with a timeout of CAP_READ_TIMEOUT milliseconds, or
685 * CAP_READ_TIMEOUT*1000 microseconds.
688 FD_SET(pcap_fd, &set1);
690 timeout.tv_usec = CAP_READ_TIMEOUT*1000;
691 if (select(pcap_fd+1, &set1, NULL, NULL, &timeout) != 0) {
693 * "select()" says we can read from it without blocking; go for
696 inpkts = pcap_dispatch(pch, 1, capture_pcap_cb, (u_char *) &ld);
700 inpkts = pcap_dispatch(pch, 1, capture_pcap_cb, (u_char *) &ld);
703 ld.sync_packets += inpkts;
704 /* Only update once a second so as not to overload slow displays */
705 cur_time = time(NULL);
706 if (cur_time > upd_time) {
709 sprintf(label_str, "Count: %d", ld.counts.total);
710 gtk_label_set(GTK_LABEL(count_lb), label_str);
712 sprintf(label_str, "TCP: %d (%.1f%%)", ld.counts.tcp,
713 pct(ld.counts.tcp, ld.counts.total));
714 gtk_label_set(GTK_LABEL(tcp_lb), label_str);
716 sprintf(label_str, "UDP: %d (%.1f%%)", ld.counts.udp,
717 pct(ld.counts.udp, ld.counts.total));
718 gtk_label_set(GTK_LABEL(udp_lb), label_str);
720 sprintf(label_str, "ICMP: %d (%.1f%%)", ld.counts.icmp,
721 pct(ld.counts.icmp, ld.counts.total));
722 gtk_label_set(GTK_LABEL(icmp_lb), label_str);
724 sprintf(label_str, "OSPF: %d (%.1f%%)", ld.counts.ospf,
725 pct(ld.counts.ospf, ld.counts.total));
726 gtk_label_set(GTK_LABEL(ospf_lb), label_str);
728 sprintf(label_str, "GRE: %d (%.1f%%)", ld.counts.gre,
729 pct(ld.counts.gre, ld.counts.total));
730 gtk_label_set(GTK_LABEL(gre_lb), label_str);
732 sprintf(label_str, "NetBIOS: %d (%.1f%%)", ld.counts.netbios,
733 pct(ld.counts.netbios, ld.counts.total));
734 gtk_label_set(GTK_LABEL(netbios_lb), label_str);
736 sprintf(label_str, "IPX: %d (%.1f%%)", ld.counts.ipx,
737 pct(ld.counts.ipx, ld.counts.total));
738 gtk_label_set(GTK_LABEL(ipx_lb), label_str);
740 sprintf(label_str, "Other: %d (%.1f%%)", ld.counts.other,
741 pct(ld.counts.other, ld.counts.total));
742 gtk_label_set(GTK_LABEL(other_lb), label_str);
744 /* do sync here, too */
745 fflush(wtap_dump_file(ld.pdh));
746 if (capture_child && ld.sync_packets) {
747 /* This is the child process for a sync mode capture, so send
748 our parent a message saying we've written out "ld.sync_packets"
749 packets to the capture file. */
751 sprintf(tmp, "%d*", ld.sync_packets);
752 write(1, tmp, strlen(tmp));
758 if (!wtap_dump_close(ld.pdh, &err)) {
759 /* XXX - in fork mode, this may not pop up, or, if it does,
760 it may disappear as soon as we exit.
762 We should have the parent process, while it's reading
763 the packet count update messages, catch error messages
764 and pop up a message box if it sees one. */
767 case WTAP_ERR_CANT_CLOSE:
768 simple_dialog(ESD_TYPE_WARN, NULL,
769 "The file to which the capture was being saved"
770 " couldn't be closed for some unknown reason.");
773 case WTAP_ERR_SHORT_WRITE:
774 simple_dialog(ESD_TYPE_WARN, NULL,
775 "Not all the data could be written to the file"
776 " to which the capture was being saved.");
780 simple_dialog(ESD_TYPE_WARN, NULL,
781 "The file to which the capture was being"
782 " saved (\"%s\") could not be closed: %s.",
783 cf.save_file, wtap_strerror(err));
789 gtk_grab_remove(GTK_WIDGET(cap_w));
790 gtk_widget_destroy(GTK_WIDGET(cap_w));
795 /* We couldn't even start the capture, so get rid of the capture
797 unlink(cf.save_file); /* silently ignore error */
798 g_free(cf.save_file);
801 /* This is the child process for a sync mode capture.
802 Send the error message to our parent, so they can display a
803 dialog box containing it. */
804 int msglen = strlen(errmsg);
806 sprintf(lenbuf, "%u;", msglen);
807 write(1, lenbuf, strlen(lenbuf));
808 write(1, errmsg, msglen);
810 /* Display the dialog box ourselves; there's no parent. */
811 simple_dialog(ESD_TYPE_WARN, NULL, errmsg);
820 pct(gint num, gint denom) {
822 return (float) num * 100.0 / (float) denom;
829 capture_stop_cb(GtkWidget *w, gpointer data) {
830 loop_data *ld = (loop_data *) data;
836 capture_pcap_cb(u_char *user, const struct pcap_pkthdr *phdr,
838 struct wtap_pkthdr whdr;
839 loop_data *ld = (loop_data *) user;
842 if ((++ld->counts.total >= ld->max) && (ld->max > 0))
848 whdr.caplen = phdr->caplen;
849 whdr.len = phdr->len;
850 whdr.pkt_encap = ld->linktype;
852 /* XXX - do something if this fails */
853 wtap_dump(ld->pdh, &whdr, pd, &err);
856 switch (ld->linktype) {
857 case WTAP_ENCAP_ETHERNET:
858 capture_eth(pd, phdr->caplen, &ld->counts);
860 case WTAP_ENCAP_FDDI:
861 case WTAP_ENCAP_FDDI_BITSWAPPED:
862 capture_fddi(pd, phdr->caplen, &ld->counts);
865 capture_tr(pd, phdr->caplen, &ld->counts);
867 case WTAP_ENCAP_NULL:
868 capture_null(pd, phdr->caplen, &ld->counts);
871 capture_ppp(pd, phdr->caplen, &ld->counts);
873 case WTAP_ENCAP_RAW_IP:
874 capture_raw(pd, phdr->caplen, &ld->counts);
876 /* XXX - FreeBSD may append 4-byte ATM pseudo-header to DLT_ATM_RFC1483,
877 with LLC header following; we should implement it at some
882 #endif /* HAVE_LIBPCAP */