/* capture-pcap-util-unix.c * UN*X-specific utility routines for packet capture * * $Id$ * * Wireshark - 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 #include #ifdef HAVE_LIBPCAP #include #include #include #include #ifdef HAVE_UNISTD_H #include #endif #ifdef HAVE_SYS_SOCKET_H #include #endif #ifdef HAVE_SYS_IOCTL_H #include #endif #include /* * Keep Digital UNIX happy when including . */ struct mbuf; struct rtentry; #include #ifdef HAVE_SYS_SOCKIO_H # include #endif #include "capture-pcap-util.h" #include "capture-pcap-util-int.h" #ifndef HAVE_PCAP_FINDALLDEVS struct search_user_data { char *name; if_info_t *if_info; }; static void search_for_if_cb(gpointer data, gpointer user_data); #endif GList * get_interface_list(int *err, char *err_str) { #ifdef HAVE_PCAP_FINDALLDEVS return get_interface_list_findalldevs(err, err_str); #else GList *il = NULL; gint nonloopback_pos = 0; struct ifreq *ifr, *last; struct ifconf ifc; struct ifreq ifrflags; int sock = socket(AF_INET, SOCK_DGRAM, 0); struct search_user_data user_data; pcap_t *pch; int len, lastlen; char *buf; if_info_t *if_info; if (sock < 0) { *err = CANT_GET_INTERFACE_LIST; g_snprintf(err_str, PCAP_ERRBUF_SIZE, "Error opening socket: %s", strerror(errno)); return NULL; } /* * This code came from: W. Richard Stevens: "UNIX Network Programming", * Networking APIs: Sockets and XTI, Vol 1, page 434. */ lastlen = 0; len = 100 * sizeof(struct ifreq); for ( ; ; ) { buf = g_malloc(len); ifc.ifc_len = len; ifc.ifc_buf = buf; memset (buf, 0, len); if (ioctl(sock, SIOCGIFCONF, &ifc) < 0) { if (errno != EINVAL || lastlen != 0) { g_snprintf(err_str, PCAP_ERRBUF_SIZE, "SIOCGIFCONF ioctl error getting list of interfaces: %s", strerror(errno)); goto fail; } } else { if ((unsigned) ifc.ifc_len < sizeof(struct ifreq)) { g_snprintf(err_str, PCAP_ERRBUF_SIZE, "SIOCGIFCONF ioctl gave too small return buffer"); goto fail; } if (ifc.ifc_len == lastlen) break; /* success, len has not changed */ lastlen = ifc.ifc_len; } len += 10 * sizeof(struct ifreq); /* increment */ g_free(buf); } ifr = (struct ifreq *) ifc.ifc_req; last = (struct ifreq *) ((char *) ifr + ifc.ifc_len); while (ifr < last) { /* * Skip entries that begin with "dummy", or that include * a ":" (the latter are Solaris virtuals). */ if (strncmp(ifr->ifr_name, "dummy", 5) == 0 || strchr(ifr->ifr_name, ':') != NULL) goto next; /* * If we already have this interface name on the list, * don't add it, but, if we don't already have an IP * address for it, add that address (SIOCGIFCONF returns, * at least on BSD-flavored systems, one entry per * interface *address*; if an interface has multiple * addresses, we get multiple entries for it). */ user_data.name = ifr->ifr_name; user_data.if_info = NULL; g_list_foreach(il, search_for_if_cb, &user_data); if (user_data.if_info != NULL) { if_info_add_address(user_data.if_info, &ifr->ifr_addr); goto next; } /* * Get the interface flags. */ memset(&ifrflags, 0, sizeof ifrflags); strncpy(ifrflags.ifr_name, ifr->ifr_name, sizeof ifrflags.ifr_name); if (ioctl(sock, SIOCGIFFLAGS, (char *)&ifrflags) < 0) { if (errno == ENXIO) goto next; g_snprintf(err_str, PCAP_ERRBUF_SIZE, "SIOCGIFFLAGS error getting flags for interface %s: %s", ifr->ifr_name, strerror(errno)); goto fail; } /* * Skip interfaces that aren't up. */ if (!(ifrflags.ifr_flags & IFF_UP)) goto next; /* * Skip interfaces that we can't open with "libpcap". * Open with the minimum packet size - it appears that the * IRIX SIOCSNOOPLEN "ioctl" may fail if the capture length * supplied is too large, rather than just truncating it. */ pch = pcap_open_live(ifr->ifr_name, MIN_PACKET_SIZE, 0, 0, err_str); if (pch == NULL) goto next; pcap_close(pch); /* * If it's a loopback interface, add it at the end of the * list, otherwise add it after the last non-loopback * interface, so all loopback interfaces go at the end - we * don't want a loopback interface to be the default capture * device unless there are no non-loopback devices. */ if_info = if_info_new(ifr->ifr_name, NULL); if_info_add_address(if_info, &ifr->ifr_addr); if ((ifrflags.ifr_flags & IFF_LOOPBACK) || strncmp(ifr->ifr_name, "lo", 2) == 0) { if_info->loopback = TRUE; il = g_list_append(il, if_info); } else { if_info->loopback = FALSE; il = g_list_insert(il, if_info, nonloopback_pos); /* * Insert the next non-loopback interface after this * one. */ nonloopback_pos++; } next: #ifdef HAVE_SA_LEN ifr = (struct ifreq *) ((char *) ifr + (ifr->ifr_addr.sa_len > sizeof(ifr->ifr_addr) ? ifr->ifr_addr.sa_len : sizeof(ifr->ifr_addr)) + IFNAMSIZ); #else ifr = (struct ifreq *) ((char *) ifr + sizeof(struct ifreq)); #endif } #ifdef linux /* * OK, maybe we have support for the "any" device, to do a cooked * capture on all interfaces at once. * Try opening it and, if that succeeds, add it to the end of * the list of interfaces. */ pch = pcap_open_live("any", MIN_PACKET_SIZE, 0, 0, err_str); if (pch != NULL) { /* * It worked; we can use the "any" device. */ if_info = if_info_new("any", "Pseudo-device that captures on all interfaces"); il = g_list_insert(il, if_info, -1); pcap_close(pch); } #endif g_free(ifc.ifc_buf); close(sock); if (il == NULL) { /* * No interfaces found. */ *err = NO_INTERFACES_FOUND; } return il; fail: if (il != NULL) free_interface_list(il); g_free(ifc.ifc_buf); close(sock); *err = CANT_GET_INTERFACE_LIST; return NULL; #endif /* HAVE_PCAP_FINDALLDEVS */ } #ifndef HAVE_PCAP_FINDALLDEVS static void search_for_if_cb(gpointer data, gpointer user_data) { struct search_user_data *search_user_data = user_data; if_info_t *if_info = data; if (strcmp(if_info->name, search_user_data->name) == 0) search_user_data->if_info = if_info; } #endif /* HAVE_PCAP_FINDALLDEVS */ /* * Get an error message string for a CANT_GET_INTERFACE_LIST error from * "get_interface_list()". */ gchar * cant_get_if_list_error_message(const char *err_str) { return g_strdup_printf("Can't get list of interfaces: %s", err_str); } /* * Append the version of libpcap with which we were compiled to a GString. */ void get_compiled_pcap_version(GString *str) { #ifdef HAVE_PCAP_VERSION extern char pcap_version[]; g_string_sprintfa(str, "with libpcap %s", pcap_version); #else g_string_append(str, "with libpcap (version unknown)"); #endif } /* * Append the version of libpcap with which we we're running to a GString. */ void get_runtime_pcap_version(GString *str) { g_string_sprintfa(str, "with "); #ifdef HAVE_PCAP_LIB_VERSION g_string_sprintfa(str, pcap_lib_version()); #else g_string_append(str, "libpcap (version unknown)"); #endif } #else /* HAVE_LIBPCAP */ /* * Append an indication that we were not compiled with libpcap * to a GString. */ void get_compiled_pcap_version(GString *str) { g_string_append(str, "without libpcap"); } /* * Don't append anything, as we weren't even compiled to use WinPcap. */ void get_runtime_pcap_version(GString *str _U_) { } #endif /* HAVE_LIBPCAP */