/* capture.c * Routines for packet capture windows * * $Id: capture.c,v 1.80 1999/10/20 22:35:57 gram Exp $ * * 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 #ifdef HAVE_SYS_TYPES_H # include #endif #ifdef HAVE_SYS_STAT_H # include #endif #include #include #include #include #include #include #ifdef HAVE_UNISTD_H #include #endif #include #ifdef HAVE_SYS_SOCKET_H #include #endif #ifdef HAVE_SYS_IOCTL_H #include #endif #ifdef HAVE_NET_IF_H #include #endif #include #include #ifdef NEED_SNPRINTF_H # ifdef HAVE_STDARG_H # include # else # include # endif # include "snprintf.h" #endif #ifndef lib_pcap_h #include #endif #include "gtk/main.h" #include "gtk/gtkglobals.h" #include "packet.h" #include "file.h" #include "gtk/menu.h" #include "capture.h" #include "util.h" #include "prefs.h" #include "globals.h" int sync_mode; /* fork a child to do the capture, and sync between them */ int sync_pipe[2]; /* used to sync father */ int quit_after_cap; /* Makes a "capture only mode". Implies -k */ gboolean capture_child; /* if this is the child for "-S" */ static void capture_stop_cb(GtkWidget *, gpointer); static void capture_pcap_cb(u_char *, const struct pcap_pkthdr *, const u_char *); static float pct(gint, gint); typedef struct _loop_data { gint go; gint max; gint linktype; gint sync_packets; packet_counts counts; wtap_dumper *pdh; } loop_data; /* Open a specified file, or create a temporary file, and start a capture to the file in question. */ void do_capture(char *capfile_name) { char tmpname[128+1]; gboolean is_temp_file; u_char c; int i; guint byte_count; char *msg; int err; int capture_succeeded; if (capfile_name != NULL) { /* Try to open/create the specified file for use as a capture buffer. */ cf.save_file_fd = open(capfile_name, O_RDWR|O_TRUNC|O_CREAT, 0600); is_temp_file = FALSE; } else { /* Choose a random name for the capture buffer */ cf.save_file_fd = create_tempfile(tmpname, sizeof tmpname, "ether"); capfile_name = g_strdup(tmpname); is_temp_file = TRUE; } if (cf.save_file_fd == -1) { simple_dialog(ESD_TYPE_WARN, NULL, "The file to which the capture would be saved (\"%s\")" "could not be opened: %s.", tmpname, strerror(errno)); return; } close_cap_file(&cf, info_bar, file_ctx); if (cf.save_file != NULL) { /* If the current file is a temporary capture file, remove it. */ if (!cf.user_saved) unlink(cf.save_file); /* silently ignore error */ g_free(cf.save_file); } cf.save_file = capfile_name; cf.user_saved = !is_temp_file; if (sync_mode) { /* use fork() for capture */ int fork_child; char ssnap[24]; char scount[24]; /* need a constant for len of numbers */ char save_file_fd[24]; sprintf(ssnap,"%d",cf.snap); /* in lieu of itoa */ sprintf(scount,"%d",cf.count); sprintf(save_file_fd,"%d",cf.save_file_fd); signal(SIGCHLD, SIG_IGN); pipe(sync_pipe); if ((fork_child = fork()) == 0) { /* args: -i interface specification * -w file to write * -W file descriptor to write * -c count to capture * -s snaplen * -m / -b fonts * -f "filter expression" */ close(1); dup(sync_pipe[1]); close(sync_pipe[0]); execlp(ethereal_path, CHILD_NAME, "-i", cf.iface, "-w", cf.save_file, "-W", save_file_fd, "-c", scount, "-s", ssnap, "-m", medium_font, "-b", bold_font, (cf.cfilter == NULL)? 0 : "-f", (cf.cfilter == NULL)? 0 : cf.cfilter, (const char *)NULL); } else { cf.filename = cf.save_file; close(sync_pipe[1]); /* Read a byte count from "sync_pipe[0]", terminated with a colon; if the count is 0, the child process created the capture file and we should start reading from it, otherwise the capture couldn't start and the count is a count of bytes of error message, and we should display the message. */ byte_count = 0; for (;;) { i = read(sync_pipe[0], &c, 1); if (i == 0) { /* EOF - the child process died. XXX - reap it and report the status. */ simple_dialog(ESD_TYPE_WARN, NULL, "Capture child process died"); return; } if (c == ';') break; if (!isdigit(c)) { /* Child process handed us crap. */ simple_dialog(ESD_TYPE_WARN, NULL, "Capture child process sent us a bad message"); return; } byte_count = byte_count*10 + c - '0'; } if (byte_count == 0) { /* Success. */ err = tail_cap_file(cf.save_file, &cf); if (err != 0) { simple_dialog(ESD_TYPE_WARN, NULL, file_open_error_message(err, FALSE), cf.save_file); } } else { /* Failure. */ msg = g_malloc(byte_count + 1); if (msg == NULL) { simple_dialog(ESD_TYPE_WARN, NULL, "Capture child process failed, but its error message was too big."); } else { i = read(sync_pipe[0], msg, byte_count); if (i < 0) { simple_dialog(ESD_TYPE_WARN, NULL, "Capture child process failed: Error %s reading its error message.", strerror(errno)); } else if (i == 0) { simple_dialog(ESD_TYPE_WARN, NULL, "Capture child process failed: EOF reading its error message."); } else simple_dialog(ESD_TYPE_WARN, NULL, msg); g_free(msg); } } } } else { capture_succeeded = capture(); if (quit_after_cap) { /* DON'T unlink the save file. Presumably someone wants it. */ gtk_exit(0); } if (capture_succeeded) { /* Capture succeeded; read in the capture file. */ if ((err = open_cap_file(cf.save_file, &cf)) == 0) { /* Set the read filter to NULL. */ cf.rfcode = NULL; err = read_cap_file(&cf); set_menu_sensitivity("/File/Save", TRUE); set_menu_sensitivity("/File/Save As...", FALSE); } } } } /* Do the low-level work of a capture. Returns TRUE if it succeeds, FALSE otherwise. */ int capture(void) { GtkWidget *cap_w, *main_vb, *count_lb, *tcp_lb, *udp_lb, *icmp_lb, *ospf_lb, *gre_lb, *netbios_lb, *other_lb, *stop_bt; pcap_t *pch; gchar err_str[PCAP_ERRBUF_SIZE], label_str[32]; loop_data ld; bpf_u_int32 netnum, netmask; time_t upd_time, cur_time; int err, inpkts; char errmsg[1024+1]; ld.go = TRUE; ld.counts.total = 0; ld.max = cf.count; ld.linktype = WTAP_ENCAP_UNKNOWN; ld.sync_packets = 0; ld.counts.tcp = 0; ld.counts.udp = 0; ld.counts.icmp = 0; ld.counts.ospf = 0; ld.counts.gre = 0; ld.counts.netbios = 0; ld.counts.other = 0; ld.pdh = NULL; /* Open the network interface to capture from it. */ pch = pcap_open_live(cf.iface, cf.snap, 1, 250, err_str); if (pch == NULL) { /* Well, we couldn't start the capture. If this is a child process that does the capturing in sync mode or fork mode, it shouldn't do any UI stuff until we pop up the capture-progress window, and, since we couldn't start the capture, we haven't popped it up. */ if (!capture_child) { while (gtk_events_pending()) gtk_main_iteration(); } snprintf(errmsg, sizeof errmsg, "The capture session could not be initiated (%s).\n" "Please check to make sure you have sufficient permissions, and that\n" "you have the proper interface specified.", err_str); goto error; } if (cf.cfilter) { /* A capture filter was specified; set it up. */ if (pcap_lookupnet (cf.iface, &netnum, &netmask, err_str) < 0) { snprintf(errmsg, sizeof errmsg, "Can't use filter: Couldn't obtain netmask info (%s).", err_str); goto error; } if (pcap_compile(pch, &cf.fcode, cf.cfilter, 1, netmask) < 0) { snprintf(errmsg, sizeof errmsg, "Unable to parse filter string (%s).", pcap_geterr(pch)); goto error; } if (pcap_setfilter(pch, &cf.fcode) < 0) { snprintf(errmsg, sizeof errmsg, "Can't install filter (%s).", pcap_geterr(pch)); goto error; } } /* Set up to write to the capture file. */ ld.linktype = wtap_pcap_encap_to_wtap_encap(pcap_datalink(pch)); if (ld.linktype == WTAP_ENCAP_UNKNOWN) { strcpy(errmsg, "The network you're capturing from is of a type" " that Ethereal doesn't support."); goto error; } ld.pdh = wtap_dump_fdopen(cf.save_file_fd, WTAP_FILE_PCAP, ld.linktype, pcap_snapshot(pch), &err); if (ld.pdh == NULL) { /* We couldn't set up to write to the capture file. */ switch (err) { case WTAP_ERR_CANT_OPEN: strcpy(errmsg, "The file to which the capture would be saved" " couldn't be created for some unknown reason."); break; case WTAP_ERR_SHORT_WRITE: strcpy(errmsg, "A full header couldn't be written to the file" " to which the capture would be saved."); break; default: if (err < 0) { sprintf(errmsg, "The file to which the capture would be" " saved (\"%s\") could not be opened: Error %d.", cf.save_file, err); } else { sprintf(errmsg, "The file to which the capture would be" " saved (\"%s\") could not be opened: %s.", cf.save_file, strerror(err)); } break; } goto error; } if (capture_child) { /* Well, we should be able to start capturing. This is the child process for a sync mode capture, so sync out the capture file, so the header makes it to the file system, and send a "capture started successfully and capture file created" message to our parent so that they'll open the capture file and update its windows to indicate that we have a live capture in progress. */ fflush(wtap_dump_file(ld.pdh)); write(1, "0;", 2); } cap_w = gtk_window_new(GTK_WINDOW_TOPLEVEL); gtk_window_set_title(GTK_WINDOW(cap_w), "Ethereal: Capture / Playback"); /* Container for capture display widgets */ main_vb = gtk_vbox_new(FALSE, 1); gtk_container_border_width(GTK_CONTAINER(main_vb), 5); gtk_container_add(GTK_CONTAINER(cap_w), main_vb); gtk_widget_show(main_vb); count_lb = gtk_label_new("Count: 0"); gtk_box_pack_start(GTK_BOX(main_vb), count_lb, FALSE, FALSE, 3); gtk_widget_show(count_lb); tcp_lb = gtk_label_new("TCP: 0 (0.0%)"); gtk_box_pack_start(GTK_BOX(main_vb), tcp_lb, FALSE, FALSE, 3); gtk_widget_show(tcp_lb); udp_lb = gtk_label_new("UDP: 0 (0.0%)"); gtk_box_pack_start(GTK_BOX(main_vb), udp_lb, FALSE, FALSE, 3); gtk_widget_show(udp_lb); icmp_lb = gtk_label_new("ICMP: 0 (0.0%)"); gtk_box_pack_start(GTK_BOX(main_vb), icmp_lb, FALSE, FALSE, 3); gtk_widget_show(icmp_lb); ospf_lb = gtk_label_new("OSPF: 0 (0.0%)"); gtk_box_pack_start(GTK_BOX(main_vb), ospf_lb, FALSE, FALSE, 3); gtk_widget_show(ospf_lb); gre_lb = gtk_label_new("GRE: 0 (0.0%)"); gtk_box_pack_start(GTK_BOX(main_vb), gre_lb, FALSE, FALSE, 3); gtk_widget_show(gre_lb); netbios_lb = gtk_label_new("NetBIOS: 0 (0.0%)"); gtk_box_pack_start(GTK_BOX(main_vb), netbios_lb, FALSE, FALSE, 3); gtk_widget_show(netbios_lb); other_lb = gtk_label_new("Other: 0 (0.0%)"); gtk_box_pack_start(GTK_BOX(main_vb), other_lb, FALSE, FALSE, 3); gtk_widget_show(other_lb); stop_bt = gtk_button_new_with_label ("Stop"); gtk_signal_connect(GTK_OBJECT(stop_bt), "clicked", GTK_SIGNAL_FUNC(capture_stop_cb), (gpointer) &ld); gtk_box_pack_end(GTK_BOX(main_vb), stop_bt, FALSE, FALSE, 3); GTK_WIDGET_SET_FLAGS(stop_bt, GTK_CAN_DEFAULT); gtk_widget_grab_default(stop_bt); GTK_WIDGET_SET_FLAGS(stop_bt, GTK_CAN_DEFAULT); gtk_widget_grab_default(stop_bt); gtk_widget_show(stop_bt); gtk_widget_show(cap_w); gtk_grab_add(cap_w); upd_time = time(NULL); while (ld.go) { while (gtk_events_pending()) gtk_main_iteration(); inpkts = pcap_dispatch(pch, 1, capture_pcap_cb, (u_char *) &ld); if (inpkts > 0) ld.sync_packets += inpkts; /* Only update once a second so as not to overload slow displays */ cur_time = time(NULL); if (cur_time > upd_time) { upd_time = cur_time; sprintf(label_str, "Count: %d", ld.counts.total); gtk_label_set(GTK_LABEL(count_lb), label_str); sprintf(label_str, "TCP: %d (%.1f%%)", ld.counts.tcp, pct(ld.counts.tcp, ld.counts.total)); gtk_label_set(GTK_LABEL(tcp_lb), label_str); sprintf(label_str, "UDP: %d (%.1f%%)", ld.counts.udp, pct(ld.counts.udp, ld.counts.total)); gtk_label_set(GTK_LABEL(udp_lb), label_str); sprintf(label_str, "ICMP: %d (%.1f%%)", ld.counts.icmp, pct(ld.counts.icmp, ld.counts.total)); gtk_label_set(GTK_LABEL(icmp_lb), label_str); sprintf(label_str, "OSPF: %d (%.1f%%)", ld.counts.ospf, pct(ld.counts.ospf, ld.counts.total)); gtk_label_set(GTK_LABEL(ospf_lb), label_str); sprintf(label_str, "GRE: %d (%.1f%%)", ld.counts.gre, pct(ld.counts.gre, ld.counts.total)); gtk_label_set(GTK_LABEL(gre_lb), label_str); sprintf(label_str, "NetBIOS: %d (%.1f%%)", ld.counts.netbios, pct(ld.counts.netbios, ld.counts.total)); gtk_label_set(GTK_LABEL(netbios_lb), label_str); sprintf(label_str, "Other: %d (%.1f%%)", ld.counts.other, pct(ld.counts.other, ld.counts.total)); gtk_label_set(GTK_LABEL(other_lb), label_str); /* do sync here, too */ fflush(wtap_dump_file(ld.pdh)); if (capture_child && ld.sync_packets) { /* This is the child process for a sync mode capture, so send our parent a message saying we've written out "ld.sync_packets" packets to the capture file. */ char tmp[20]; sprintf(tmp, "%d*", ld.sync_packets); write(1, tmp, strlen(tmp)); ld.sync_packets = 0; } } } if (!wtap_dump_close(ld.pdh, &err)) { /* XXX - in fork mode, this may not pop up, or, if it does, it may disappear as soon as we exit. We should have the parent process, while it's reading the packet count update messages, catch error messages and pop up a message box if it sees one. */ switch (err) { case WTAP_ERR_CANT_CLOSE: simple_dialog(ESD_TYPE_WARN, NULL, "The file to which the capture was being saved" " couldn't be closed for some unknown reason."); break; case WTAP_ERR_SHORT_WRITE: simple_dialog(ESD_TYPE_WARN, NULL, "Not all the data could be written to the file" " to which the capture was being saved."); break; default: if (err < 0) { simple_dialog(ESD_TYPE_WARN, NULL, "The file to which the capture was being" " saved (\"%s\") could not be closed: Error %d.", cf.save_file, err); } else { simple_dialog(ESD_TYPE_WARN, NULL, "The file to which the capture was being" " saved (\"%s\") could not be closed: %s.", cf.save_file, strerror(err)); } break; } } pcap_close(pch); gtk_grab_remove(GTK_WIDGET(cap_w)); gtk_widget_destroy(GTK_WIDGET(cap_w)); return TRUE; error: /* We couldn't even start the capture, so get rid of the capture file. */ unlink(cf.save_file); /* silently ignore error */ if (capture_child) { /* This is the child process for a sync mode capture. Send the error message to our parent, so they can display a dialog box containing it. */ int msglen = strlen(errmsg); char lenbuf[10+1+1]; sprintf(lenbuf, "%u;", msglen); write(1, lenbuf, strlen(lenbuf)); write(1, errmsg, msglen); } else { /* Display the dialog box ourselves; there's no parent. */ simple_dialog(ESD_TYPE_WARN, NULL, errmsg); } if (pch != NULL) pcap_close(pch); return FALSE; } static float pct(gint num, gint denom) { if (denom) { return (float) num * 100.0 / (float) denom; } else { return 0.0; } } static void capture_stop_cb(GtkWidget *w, gpointer data) { loop_data *ld = (loop_data *) data; ld->go = FALSE; } static void capture_pcap_cb(u_char *user, const struct pcap_pkthdr *phdr, const u_char *pd) { struct wtap_pkthdr whdr; loop_data *ld = (loop_data *) user; int err; if ((++ld->counts.total >= ld->max) && (ld->max > 0)) { ld->go = FALSE; } if (ld->pdh) { whdr.ts = phdr->ts; whdr.caplen = phdr->caplen; whdr.len = phdr->len; whdr.pkt_encap = ld->linktype; /* XXX - do something if this fails */ wtap_dump(ld->pdh, &whdr, pd, &err); } switch (ld->linktype) { case WTAP_ENCAP_ETHERNET: capture_eth(pd, phdr->caplen, &ld->counts); break; case WTAP_ENCAP_FDDI: case WTAP_ENCAP_FDDI_BITSWAPPED: capture_fddi(pd, phdr->caplen, &ld->counts); break; case WTAP_ENCAP_TR: capture_tr(pd, phdr->caplen, &ld->counts); break; case WTAP_ENCAP_NULL: capture_null(pd, phdr->caplen, &ld->counts); break; case WTAP_ENCAP_PPP: capture_ppp(pd, phdr->caplen, &ld->counts); break; case WTAP_ENCAP_RAW_IP: capture_raw(pd, phdr->caplen, &ld->counts); break; /* XXX - FreeBSD may append 4-byte ATM pseudo-header to DLT_ATM_RFC1483, with LLC header following; we should implement it at some point. */ } } #endif /* HAVE_LIBPCAP */