--- /dev/null
+/* -*- Mode: c; tab-width: 8; indent-tabs-mode: 1; c-basic-offset: 8; -*- */
+/*
+ * Copyright (c) 1994, 1995, 1996, 1997, 1998
+ * The Regents of the University of California. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the Computer Systems
+ * Engineering Group at Lawrence Berkeley Laboratory.
+ * 4. Neither the name of the University nor of the Laboratory may be used
+ * to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef lint
+static const char rcsid[] _U_ =
+ "@(#) $Header: /tcpdump/master/libpcap/fad-gifc.c,v 1.11.2.1 2008-08-06 07:35:01 guy Exp $ (LBL)";
+#endif
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <sys/param.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#ifdef HAVE_SYS_SOCKIO_H
+#include <sys/sockio.h>
+#endif
+#include <sys/time.h> /* concession to AIX */
+
+struct mbuf; /* Squelch compiler warnings on some platforms for */
+struct rtentry; /* declarations in <net/if.h> */
+#include <net/if.h>
+#include <netinet/in.h>
+
+#include <ctype.h>
+#include <errno.h>
+#include <memory.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "pcap-int.h"
+
+#ifdef HAVE_OS_PROTO_H
+#include "os-proto.h"
+#endif
+
+/*
+ * This is fun.
+ *
+ * In older BSD systems, socket addresses were fixed-length, and
+ * "sizeof (struct sockaddr)" gave the size of the structure.
+ * All addresses fit within a "struct sockaddr".
+ *
+ * In newer BSD systems, the socket address is variable-length, and
+ * there's an "sa_len" field giving the length of the structure;
+ * this allows socket addresses to be longer than 2 bytes of family
+ * and 14 bytes of data.
+ *
+ * Some commercial UNIXes use the old BSD scheme, some use the RFC 2553
+ * variant of the old BSD scheme (with "struct sockaddr_storage" rather
+ * than "struct sockaddr"), and some use the new BSD scheme.
+ *
+ * Some versions of GNU libc use neither scheme, but has an "SA_LEN()"
+ * macro that determines the size based on the address family. Other
+ * versions don't have "SA_LEN()" (as it was in drafts of RFC 2553
+ * but not in the final version).
+ *
+ * We assume that a UNIX that doesn't have "getifaddrs()" and doesn't have
+ * SIOCGLIFCONF, but has SIOCGIFCONF, uses "struct sockaddr" for the
+ * address in an entry returned by SIOCGIFCONF.
+ */
+#ifndef SA_LEN
+#ifdef HAVE_SOCKADDR_SA_LEN
+#define SA_LEN(addr) ((addr)->sa_len)
+#else /* HAVE_SOCKADDR_SA_LEN */
+#define SA_LEN(addr) (sizeof (struct sockaddr))
+#endif /* HAVE_SOCKADDR_SA_LEN */
+#endif /* SA_LEN */
+
+/*
+ * This is also fun.
+ *
+ * There is no ioctl that returns the amount of space required for all
+ * the data that SIOCGIFCONF could return, and if a buffer is supplied
+ * that's not large enough for all the data SIOCGIFCONF could return,
+ * on at least some platforms it just returns the data that'd fit with
+ * no indication that there wasn't enough room for all the data, much
+ * less an indication of how much more room is required.
+ *
+ * The only way to ensure that we got all the data is to pass a buffer
+ * large enough that the amount of space in the buffer *not* filled in
+ * is greater than the largest possible entry.
+ *
+ * We assume that's "sizeof(ifreq.ifr_name)" plus 255, under the assumption
+ * that no address is more than 255 bytes (on systems where the "sa_len"
+ * field in a "struct sockaddr" is 1 byte, e.g. newer BSDs, that's the
+ * case, and addresses are unlikely to be bigger than that in any case).
+ */
+#define MAX_SA_LEN 255
+
+#ifdef HAVE_PROC_NET_DEV
+/*
+ * Get from "/proc/net/dev" all interfaces listed there; if they're
+ * already in the list of interfaces we have, that won't add another
+ * instance, but if they're not, that'll add them.
+ *
+ * We don't bother getting any addresses for them; it appears you can't
+ * use SIOCGIFADDR on Linux to get IPv6 addresses for interfaces, and,
+ * although some other types of addresses can be fetched with SIOCGIFADDR,
+ * we don't bother with them for now.
+ *
+ * We also don't fail if we couldn't open "/proc/net/dev"; we just leave
+ * the list of interfaces as is.
+ */
+static int
+scan_proc_net_dev(pcap_if_t **devlistp, int fd, char *errbuf)
+{
+ FILE *proc_net_f;
+ char linebuf[512];
+ int linenum;
+ unsigned char *p;
+ char name[512]; /* XXX - pick a size */
+ char *q, *saveq;
+ struct ifreq ifrflags;
+ int ret = 0;
+
+ proc_net_f = fopen("/proc/net/dev", "r");
+ if (proc_net_f == NULL)
+ return (0);
+
+ for (linenum = 1;
+ fgets(linebuf, sizeof linebuf, proc_net_f) != NULL; linenum++) {
+ /*
+ * Skip the first two lines - they're headers.
+ */
+ if (linenum <= 2)
+ continue;
+
+ p = &linebuf[0];
+
+ /*
+ * Skip leading white space.
+ */
+ while (*p != '\0' && isspace(*p))
+ p++;
+ if (*p == '\0' || *p == '\n')
+ continue; /* blank line */
+
+ /*
+ * Get the interface name.
+ */
+ q = &name[0];
+ while (*p != '\0' && !isspace(*p)) {
+ if (*p == ':') {
+ /*
+ * This could be the separator between a
+ * name and an alias number, or it could be
+ * the separator between a name with no
+ * alias number and the next field.
+ *
+ * If there's a colon after digits, it
+ * separates the name and the alias number,
+ * otherwise it separates the name and the
+ * next field.
+ */
+ saveq = q;
+ while (isdigit(*p))
+ *q++ = *p++;
+ if (*p != ':') {
+ /*
+ * That was the next field,
+ * not the alias number.
+ */
+ q = saveq;
+ }
+ break;
+ } else
+ *q++ = *p++;
+ }
+ *q = '\0';
+
+ /*
+ * Get the flags for this interface, and skip it if
+ * it's not up.
+ */
+ strncpy(ifrflags.ifr_name, name, sizeof(ifrflags.ifr_name));
+ if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifrflags) < 0) {
+ if (errno == ENXIO)
+ continue;
+ (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
+ "SIOCGIFFLAGS: %.*s: %s",
+ (int)sizeof(ifrflags.ifr_name),
+ ifrflags.ifr_name,
+ pcap_strerror(errno));
+ ret = -1;
+ break;
+ }
+ if (!(ifrflags.ifr_flags & IFF_UP))
+ continue;
+
+ /*
+ * Add an entry for this interface, with no addresses.
+ */
+ if (pcap_add_if(devlistp, name, ifrflags.ifr_flags, NULL,
+ errbuf) == -1) {
+ /*
+ * Failure.
+ */
+ ret = -1;
+ break;
+ }
+ }
+ if (ret != -1) {
+ /*
+ * Well, we didn't fail for any other reason; did we
+ * fail due to an error reading the file?
+ */
+ if (ferror(proc_net_f)) {
+ (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
+ "Error reading /proc/net/dev: %s",
+ pcap_strerror(errno));
+ ret = -1;
+ }
+ }
+
+ (void)fclose(proc_net_f);
+ return (ret);
+}
+#endif /* HAVE_PROC_NET_DEV */
+
+/*
+ * Get a list of all interfaces that are up and that we can open.
+ * Returns -1 on error, 0 otherwise.
+ * The list, as returned through "alldevsp", may be null if no interfaces
+ * were up and could be opened.
+ *
+ * This is the implementation used on platforms that have SIOCGIFCONF but
+ * don't have any other mechanism for getting a list of interfaces.
+ *
+ * XXX - or platforms that have other, better mechanisms but for which
+ * we don't yet have code to use that mechanism; I think there's a better
+ * way on Linux, for example.
+ */
+int
+pcap_findalldevs(pcap_if_t **alldevsp, char *errbuf)
+{
+ pcap_if_t *devlist = NULL;
+ register int fd;
+ register struct ifreq *ifrp, *ifend, *ifnext;
+ int n;
+ struct ifconf ifc;
+ char *buf = NULL;
+ unsigned buf_size;
+#if defined (HAVE_SOLARIS) || defined (HAVE_HPUX10_20_OR_LATER)
+ char *p, *q;
+#endif
+ struct ifreq ifrflags, ifrnetmask, ifrbroadaddr, ifrdstaddr;
+ struct sockaddr *netmask, *broadaddr, *dstaddr;
+ size_t netmask_size, broadaddr_size, dstaddr_size;
+ int ret = 0;
+
+ /*
+ * Create a socket from which to fetch the list of interfaces.
+ */
+ fd = socket(AF_INET, SOCK_DGRAM, 0);
+ if (fd < 0) {
+ (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
+ "socket: %s", pcap_strerror(errno));
+ return (-1);
+ }
+
+ /*
+ * Start with an 8K buffer, and keep growing the buffer until
+ * we have more than "sizeof(ifrp->ifr_name) + MAX_SA_LEN"
+ * bytes left over in the buffer or we fail to get the
+ * interface list for some reason other than EINVAL (which is
+ * presumed here to mean "buffer is too small").
+ */
+ buf_size = 8192;
+ for (;;) {
+ buf = malloc(buf_size);
+ if (buf == NULL) {
+ (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
+ "malloc: %s", pcap_strerror(errno));
+ (void)close(fd);
+ return (-1);
+ }
+
+ ifc.ifc_len = buf_size;
+ ifc.ifc_buf = buf;
+ memset(buf, 0, buf_size);
+ if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0
+ && errno != EINVAL) {
+ (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
+ "SIOCGIFCONF: %s", pcap_strerror(errno));
+ (void)close(fd);
+ free(buf);
+ return (-1);
+ }
+ if (ifc.ifc_len < buf_size &&
+ (buf_size - ifc.ifc_len) > sizeof(ifrp->ifr_name) + MAX_SA_LEN)
+ break;
+ free(buf);
+ buf_size *= 2;
+ }
+
+ ifrp = (struct ifreq *)buf;
+ ifend = (struct ifreq *)(buf + ifc.ifc_len);
+
+ for (; ifrp < ifend; ifrp = ifnext) {
+ /*
+ * XXX - what if this isn't an IPv4 address? Can
+ * we still get the netmask, etc. with ioctls on
+ * an IPv4 socket?
+ *
+ * The answer is probably platform-dependent, and
+ * if the answer is "no" on more than one platform,
+ * the way you work around it is probably platform-
+ * dependent as well.
+ */
+ n = SA_LEN(&ifrp->ifr_addr) + sizeof(ifrp->ifr_name);
+ if (n < sizeof(*ifrp))
+ ifnext = ifrp + 1;
+ else
+ ifnext = (struct ifreq *)((char *)ifrp + n);
+
+ /*
+ * XXX - The 32-bit compatibility layer for Linux on IA-64
+ * is slightly broken. It correctly converts the structures
+ * to and from kernel land from 64 bit to 32 bit but
+ * doesn't update ifc.ifc_len, leaving it larger than the
+ * amount really used. This means we read off the end
+ * of the buffer and encounter an interface with an
+ * "empty" name. Since this is highly unlikely to ever
+ * occur in a valid case we can just finish looking for
+ * interfaces if we see an empty name.
+ */
+ if (!(*ifrp->ifr_name))
+ break;
+
+ /*
+ * Skip entries that begin with "dummy".
+ * XXX - what are these? Is this Linux-specific?
+ * Are there platforms on which we shouldn't do this?
+ */
+ if (strncmp(ifrp->ifr_name, "dummy", 5) == 0)
+ continue;
+
+ /*
+ * Get the flags for this interface, and skip it if it's
+ * not up.
+ */
+ strncpy(ifrflags.ifr_name, ifrp->ifr_name,
+ sizeof(ifrflags.ifr_name));
+ if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifrflags) < 0) {
+ if (errno == ENXIO)
+ continue;
+ (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
+ "SIOCGIFFLAGS: %.*s: %s",
+ (int)sizeof(ifrflags.ifr_name),
+ ifrflags.ifr_name,
+ pcap_strerror(errno));
+ ret = -1;
+ break;
+ }
+ if (!(ifrflags.ifr_flags & IFF_UP))
+ continue;
+
+ /*
+ * Get the netmask for this address on this interface.
+ */
+ strncpy(ifrnetmask.ifr_name, ifrp->ifr_name,
+ sizeof(ifrnetmask.ifr_name));
+ memcpy(&ifrnetmask.ifr_addr, &ifrp->ifr_addr,
+ sizeof(ifrnetmask.ifr_addr));
+ if (ioctl(fd, SIOCGIFNETMASK, (char *)&ifrnetmask) < 0) {
+ if (errno == EADDRNOTAVAIL) {
+ /*
+ * Not available.
+ */
+ netmask = NULL;
+ netmask_size = 0;
+ } else {
+ (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
+ "SIOCGIFNETMASK: %.*s: %s",
+ (int)sizeof(ifrnetmask.ifr_name),
+ ifrnetmask.ifr_name,
+ pcap_strerror(errno));
+ ret = -1;
+ break;
+ }
+ } else {
+ netmask = &ifrnetmask.ifr_addr;
+ netmask_size = SA_LEN(netmask);
+ }
+
+ /*
+ * Get the broadcast address for this address on this
+ * interface (if any).
+ */
+ if (ifrflags.ifr_flags & IFF_BROADCAST) {
+ strncpy(ifrbroadaddr.ifr_name, ifrp->ifr_name,
+ sizeof(ifrbroadaddr.ifr_name));
+ memcpy(&ifrbroadaddr.ifr_addr, &ifrp->ifr_addr,
+ sizeof(ifrbroadaddr.ifr_addr));
+ if (ioctl(fd, SIOCGIFBRDADDR,
+ (char *)&ifrbroadaddr) < 0) {
+ if (errno == EADDRNOTAVAIL) {
+ /*
+ * Not available.
+ */
+ broadaddr = NULL;
+ broadaddr_size = 0;
+ } else {
+ (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
+ "SIOCGIFBRDADDR: %.*s: %s",
+ (int)sizeof(ifrbroadaddr.ifr_name),
+ ifrbroadaddr.ifr_name,
+ pcap_strerror(errno));
+ ret = -1;
+ break;
+ }
+ } else {
+ broadaddr = &ifrbroadaddr.ifr_broadaddr;
+ broadaddr_size = SA_LEN(broadaddr);
+ }
+ } else {
+ /*
+ * Not a broadcast interface, so no broadcast
+ * address.
+ */
+ broadaddr = NULL;
+ broadaddr_size = 0;
+ }
+
+ /*
+ * Get the destination address for this address on this
+ * interface (if any).
+ */
+ if (ifrflags.ifr_flags & IFF_POINTOPOINT) {
+ strncpy(ifrdstaddr.ifr_name, ifrp->ifr_name,
+ sizeof(ifrdstaddr.ifr_name));
+ memcpy(&ifrdstaddr.ifr_addr, &ifrp->ifr_addr,
+ sizeof(ifrdstaddr.ifr_addr));
+ if (ioctl(fd, SIOCGIFDSTADDR,
+ (char *)&ifrdstaddr) < 0) {
+ if (errno == EADDRNOTAVAIL) {
+ /*
+ * Not available.
+ */
+ dstaddr = NULL;
+ dstaddr_size = 0;
+ } else {
+ (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
+ "SIOCGIFDSTADDR: %.*s: %s",
+ (int)sizeof(ifrdstaddr.ifr_name),
+ ifrdstaddr.ifr_name,
+ pcap_strerror(errno));
+ ret = -1;
+ break;
+ }
+ } else {
+ dstaddr = &ifrdstaddr.ifr_dstaddr;
+ dstaddr_size = SA_LEN(dstaddr);
+ }
+ } else {
+ /*
+ * Not a point-to-point interface, so no destination
+ * address.
+ */
+ dstaddr = NULL;
+ dstaddr_size = 0;
+ }
+
+#if defined (HAVE_SOLARIS) || defined (HAVE_HPUX10_20_OR_LATER)
+ /*
+ * If this entry has a colon followed by a number at
+ * the end, it's a logical interface. Those are just
+ * the way you assign multiple IP addresses to a real
+ * interface, so an entry for a logical interface should
+ * be treated like the entry for the real interface;
+ * we do that by stripping off the ":" and the number.
+ */
+ p = strchr(ifrp->ifr_name, ':');
+ if (p != NULL) {
+ /*
+ * We have a ":"; is it followed by a number?
+ */
+ q = p + 1;
+ while (isdigit((unsigned char)*q))
+ q++;
+ if (*q == '\0') {
+ /*
+ * All digits after the ":" until the end.
+ * Strip off the ":" and everything after
+ * it.
+ */
+ *p = '\0';
+ }
+ }
+#endif
+
+ /*
+ * Add information for this address to the list.
+ */
+ if (add_addr_to_iflist(&devlist, ifrp->ifr_name,
+ ifrflags.ifr_flags, &ifrp->ifr_addr,
+ SA_LEN(&ifrp->ifr_addr), netmask, netmask_size,
+ broadaddr, broadaddr_size, dstaddr, dstaddr_size,
+ errbuf) < 0) {
+ ret = -1;
+ break;
+ }
+ }
+ free(buf);
+
+#ifdef HAVE_PROC_NET_DEV
+ if (ret != -1) {
+ /*
+ * We haven't had any errors yet; now read "/proc/net/dev",
+ * and add to the list of interfaces all interfaces listed
+ * there that we don't already have, because, on Linux,
+ * SIOCGIFCONF reports only interfaces with IPv4 addresses,
+ * so you need to read "/proc/net/dev" to get the names of
+ * the rest of the interfaces.
+ */
+ ret = scan_proc_net_dev(&devlist, fd, errbuf);
+ }
+#endif
+ (void)close(fd);
+
+ if (ret != -1) {
+ /*
+ * We haven't had any errors yet; do any platform-specific
+ * operations to add devices.
+ */
+ if (pcap_platform_finddevs(&devlist, errbuf) < 0)
+ ret = -1;
+ }
+
+ if (ret == -1) {
+ /*
+ * We had an error; free the list we've been constructing.
+ */
+ if (devlist != NULL) {
+ pcap_freealldevs(devlist);
+ devlist = NULL;
+ }
+ }
+
+ *alldevsp = devlist;
+ return (ret);
+}
projects / libpcap / commitdiff
