]> The Tcpdump Group git mirrors - libpcap/blobdiff - inet.c
Have routines to set various internal debugging flags.
[libpcap] / inet.c
diff --git a/inet.c b/inet.c
index 29754d4b86afa60b3db199bb1588a23befcff2f7..bd59a525dfd790500dffe39ff86b7b6f7be0f24f 100644 (file)
--- a/inet.c
+++ b/inet.c
@@ -1,3 +1,4 @@
+/* -*- 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.
  * SUCH DAMAGE.
  */
 
-#ifndef lint
-static const char rcsid[] =
-    "@(#) $Header: /tcpdump/master/libpcap/inet.c,v 1.35 2000-07-29 07:42:48 assar Exp $ (LBL)";
-#endif
-
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
+#ifdef _WIN32
+#include <pcap-stdinc.h>
+#else /* _WIN32 */
+
 #include <sys/param.h>
+#ifndef MSDOS
 #include <sys/file.h>
+#endif
 #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;
-struct rtentry;
+struct mbuf;           /* Squelch compiler warnings on some platforms for */
+struct rtentry;                /* declarations in <net/if.h> */
 #include <net/if.h>
 #include <netinet/in.h>
+#endif /* _WIN32 */
 
 #include <ctype.h>
 #include <errno.h>
@@ -60,9 +62,13 @@ struct rtentry;
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#if !defined(_WIN32) && !defined(__BORLANDC__)
 #include <unistd.h>
-#ifdef HAVE_IFADDRS_H
-#include <ifaddrs.h>
+#endif /* !_WIN32 && !__BORLANDC__ */
+#ifdef HAVE_LIMITS_H
+#include <limits.h>
+#else
+#define INT_MAX                2147483647
 #endif
 
 #include "pcap-int.h"
@@ -73,204 +79,843 @@ struct rtentry;
 
 /* Not all systems have IFF_LOOPBACK */
 #ifdef IFF_LOOPBACK
-#define ISLOOPBACK(p) ((p)->ifr_flags & IFF_LOOPBACK)
-#define ISLOOPBACK_IFA(p) ((p)->ifa_flags & IFF_LOOPBACK)
+#define ISLOOPBACK(name, flags) ((flags) & IFF_LOOPBACK)
+#else
+#define ISLOOPBACK(name, flags) ((name)[0] == 'l' && (name)[1] == 'o' && \
+    (isdigit((unsigned char)((name)[2])) || (name)[2] == '\0'))
+#endif
+
+#ifdef IFF_UP
+#define ISUP(flags) ((flags) & IFF_UP)
+#else
+#define ISUP(flags) 0
+#endif
+
+#ifdef IFF_RUNNING
+#define ISRUNNING(flags) ((flags) & IFF_RUNNING)
 #else
-#define ISLOOPBACK(p) ((p)->ifr_name[0] == 'l' && (p)->ifr_name[1] == 'o' && \
-    (isdigit((p)->ifr_name[2]) || (p)->ifr_name[2] == '\0'))
-#define ISLOOPBACK_IFA(p) ((p)->ifa_name[0] == 'l' && (p)->ifa_name[1] == 'o' && \
-    (isdigit((p)->ifa_name[2]) || (p)->ifa_name[2] == '\0'))
+#define ISRUNNING(flags) 0
 #endif
 
+struct sockaddr *
+dup_sockaddr(struct sockaddr *sa, size_t sa_length)
+{
+       struct sockaddr *newsa;
+
+       if ((newsa = malloc(sa_length)) == NULL)
+               return (NULL);
+       return (memcpy(newsa, sa, sa_length));
+}
+
 /*
- * Return the name of a network interface attached to the system, or NULL
- * if none can be found.  The interface must be configured up; the
- * lowest unit number is preferred; loopback is ignored.
+ * Construct a "figure of merit" for an interface, for use when sorting
+ * the list of interfaces, in which interfaces that are up are superior
+ * to interfaces that aren't up, interfaces that are up and running are
+ * superior to interfaces that are up but not running, and non-loopback
+ * interfaces that are up and running are superior to loopback interfaces,
+ * and interfaces with the same flags have a figure of merit that's higher
+ * the lower the instance number.
+ *
+ * The goal is to try to put the interfaces most likely to be useful for
+ * capture at the beginning of the list.
+ *
+ * The figure of merit, which is lower the "better" the interface is,
+ * has the uppermost bit set if the interface isn't running, the bit
+ * below that set if the interface isn't up, the bit below that set
+ * if the interface is a loopback interface, and the interface index
+ * in the 29 bits below that.  (Yes, we assume u_int is 32 bits.)
  */
-char *
-pcap_lookupdev(errbuf)
-       register char *errbuf;
+static u_int
+get_figure_of_merit(pcap_if_t *dev)
 {
-#ifdef HAVE_IFADDRS_H
-       struct ifaddrs *ifap, *ifa, *mp;
-       int n, minunit;
-       char *cp;
-       static char device[IF_NAMESIZE + 1];
+       const char *cp;
+       u_int n;
+
+       if (strcmp(dev->name, "any") == 0) {
+               /*
+                * Give the "any" device an artificially high instance
+                * number, so it shows up after all other non-loopback
+                * interfaces.
+                */
+               n = 0x1FFFFFFF; /* 29 all-1 bits */
+       } else {
+               /*
+                * A number at the end of the device name string is
+                * assumed to be a unit number.
+                */
+               cp = dev->name + strlen(dev->name) - 1;
+               while (cp-1 >= dev->name && *(cp-1) >= '0' && *(cp-1) <= '9')
+                       cp--;
+               if (*cp >= '0' && *cp <= '9')
+                       n = atoi(cp);
+               else
+                       n = 0;
+       }
+       if (!(dev->flags & PCAP_IF_RUNNING))
+               n |= 0x80000000;
+       if (!(dev->flags & PCAP_IF_UP))
+               n |= 0x40000000;
+       if (dev->flags & PCAP_IF_LOOPBACK)
+               n |= 0x20000000;
+       return (n);
+}
 
-       if (getifaddrs(&ifap) != 0) {
-               (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
-                   "getifaddrs: %s", pcap_strerror(errno));
-               return NULL;
+/*
+ * Look for a given device in the specified list of devices.
+ *
+ * If we find it, return 0 and set *curdev_ret to point to it.
+ *
+ * If we don't find it, check whether we can open it:
+ *
+ *     If that fails with PCAP_ERROR_NO_SUCH_DEVICE or
+ *     PCAP_ERROR_IFACE_NOT_UP, don't attempt to add an entry for
+ *     it, as that probably means it exists but doesn't support
+ *     packet capture.
+ *
+ *     Otherwise, attempt to add an entry for it, with the specified
+ *     ifnet flags and description, and, if that succeeds, return 0
+ *     and set *curdev_ret to point to the new entry, otherwise
+ *     return PCAP_ERROR and set errbuf to an error message.
+ */
+int
+add_or_find_if(pcap_if_t **curdev_ret, pcap_if_t **alldevs, const char *name,
+    u_int flags, const char *description, char *errbuf)
+{
+       pcap_t *p;
+       pcap_if_t *curdev, *prevdev, *nextdev;
+       u_int this_figure_of_merit, nextdev_figure_of_merit;
+       char open_errbuf[PCAP_ERRBUF_SIZE];
+       int ret;
+
+       /*
+        * Is there already an entry in the list for this interface?
+        */
+       for (curdev = *alldevs; curdev != NULL; curdev = curdev->next) {
+               if (strcmp(name, curdev->name) == 0)
+                       break;  /* yes, we found it */
        }
 
-       mp = NULL;
-       minunit = 666;
-       for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
-               const char *endcp;
+       if (curdev == NULL) {
+               /*
+                * No, we didn't find it.
+                *
+                * Can we open this interface for live capture?
+                *
+                * We do this check so that interfaces that are
+                * supplied by the interface enumeration mechanism
+                * we're using but that don't support packet capture
+                * aren't included in the list.  Loopback interfaces
+                * on Solaris are an example of this; we don't just
+                * omit loopback interfaces on all platforms because
+                * you *can* capture on loopback interfaces on some
+                * OSes.
+                *
+                * On OS X, we don't do this check if the device
+                * name begins with "wlt"; at least some versions
+                * of OS X offer monitor mode capturing by having
+                * a separate "monitor mode" device for each wireless
+                * adapter, rather than by implementing the ioctls
+                * that {Free,Net,Open,DragonFly}BSD provide.
+                * Opening that device puts the adapter into monitor
+                * mode, which, at least for some adapters, causes
+                * them to deassociate from the network with which
+                * they're associated.
+                *
+                * Instead, we try to open the corresponding "en"
+                * device (so that we don't end up with, for users
+                * without sufficient privilege to open capture
+                * devices, a list of adapters that only includes
+                * the wlt devices).
+                */
+#ifdef __APPLE__
+               if (strncmp(name, "wlt", 3) == 0) {
+                       char *en_name;
+                       size_t en_name_len;
 
-               if ((ifa->ifa_flags & IFF_UP) == 0 || ISLOOPBACK_IFA(ifa))
-                       continue;
+                       /*
+                        * Try to allocate a buffer for the "en"
+                        * device's name.
+                        */
+                       en_name_len = strlen(name) - 1;
+                       en_name = malloc(en_name_len + 1);
+                       if (en_name == NULL) {
+                               (void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
+                                   "malloc: %s", pcap_strerror(errno));
+                               return (-1);
+                       }
+                       strcpy(en_name, "en");
+                       strcat(en_name, name + 3);
+                       p = pcap_create(en_name, open_errbuf);
+                       free(en_name);
+               } else
+#endif /* __APPLE */
+               p = pcap_create(name, open_errbuf);
+               if (p == NULL) {
+                       /*
+                        * The attempt to create the pcap_t failed;
+                        * that's probably an indication that we're
+                        * out of memory.
+                        *
+                        * Don't bother including this interface,
+                        * but don't treat it as an error.
+                        */
+                       *curdev_ret = NULL;
+                       return (0);
+               }
+               /* Small snaplen, so we don't try to allocate much memory. */
+               pcap_set_snaplen(p, 68);
+               ret = pcap_activate(p);
+               pcap_close(p);
+               switch (ret) {
 
-               endcp = ifa->ifa_name + strlen(ifa->ifa_name);
-               for (cp = ifa->ifa_name; cp < endcp && !isdigit(*cp); ++cp)
-                       continue;
+               case PCAP_ERROR_NO_SUCH_DEVICE:
+               case PCAP_ERROR_IFACE_NOT_UP:
+                       /*
+                        * We expect these two errors - they're the
+                        * reason we try to open the device.
+                        *
+                        * PCAP_ERROR_NO_SUCH_DEVICE typically means
+                        * "there's no such device *known to the
+                        * OS's capture mechanism*", so, even though
+                        * it might be a valid network interface, you
+                        * can't capture on it (e.g., the loopback
+                        * device in Solaris up to Solaris 10, or
+                        * the vmnet devices in OS X with VMware
+                        * Fusion).  We don't include those devices
+                        * in our list of devices, as there's no
+                        * point in doing so - they're not available
+                        * for capture.
+                        *
+                        * PCAP_ERROR_IFACE_NOT_UP means that the
+                        * OS's capture mechanism doesn't work on
+                        * interfaces not marked as up; some capture
+                        * mechanisms *do* support that, so we no
+                        * longer reject those interfaces out of hand,
+                        * but we *do* want to reject them if they
+                        * can't be opened for capture.
+                        */
+                       *curdev_ret = NULL;
+                       return (0);
+               }
 
-               if (isdigit (*cp)) {
-                       n = atoi(cp);
+               /*
+                * Yes, we can open it, or we can't, for some other
+                * reason.
+                *
+                * If we can open it, we want to offer it for
+                * capture, as you can capture on it.  If we can't,
+                * we want to offer it for capture, so that, if
+                * the user tries to capture on it, they'll get
+                * an error and they'll know why they can't
+                * capture on it (e.g., insufficient permissions)
+                * or they'll report it as a problem (and then
+                * have the error message to provide as information).
+                *
+                * Allocate a new entry.
+                */
+               curdev = malloc(sizeof(pcap_if_t));
+               if (curdev == NULL) {
+                       (void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
+                           "malloc: %s", pcap_strerror(errno));
+                       return (-1);
+               }
+
+               /*
+                * Fill in the entry.
+                */
+               curdev->next = NULL;
+               curdev->name = strdup(name);
+               if (curdev->name == NULL) {
+                       (void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
+                           "malloc: %s", pcap_strerror(errno));
+                       free(curdev);
+                       return (-1);
+               }
+               if (description != NULL) {
+                       /*
+                        * We have a description for this interface.
+                        */
+                       curdev->description = strdup(description);
+                       if (curdev->description == NULL) {
+                               (void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
+                                   "malloc: %s", pcap_strerror(errno));
+                               free(curdev->name);
+                               free(curdev);
+                               return (-1);
+                       }
                } else {
-                       n = 0;
+                       /*
+                        * We don't.
+                        */
+                       curdev->description = NULL;
                }
-               if (n < minunit) {
-                       minunit = n;
-                       mp = ifa;
+               curdev->addresses = NULL;       /* list starts out as empty */
+               curdev->flags = 0;
+               if (ISLOOPBACK(name, flags))
+                       curdev->flags |= PCAP_IF_LOOPBACK;
+               if (ISUP(flags))
+                       curdev->flags |= PCAP_IF_UP;
+               if (ISRUNNING(flags))
+                       curdev->flags |= PCAP_IF_RUNNING;
+
+               /*
+                * Add it to the list, in the appropriate location.
+                * First, get the "figure of merit" for this
+                * interface.
+                */
+               this_figure_of_merit = get_figure_of_merit(curdev);
+
+               /*
+                * Now look for the last interface with an figure of merit
+                * less than or equal to the new interface's figure of
+                * merit.
+                *
+                * We start with "prevdev" being NULL, meaning we're before
+                * the first element in the list.
+                */
+               prevdev = NULL;
+               for (;;) {
+                       /*
+                        * Get the interface after this one.
+                        */
+                       if (prevdev == NULL) {
+                               /*
+                                * The next element is the first element.
+                                */
+                               nextdev = *alldevs;
+                       } else
+                               nextdev = prevdev->next;
+
+                       /*
+                        * Are we at the end of the list?
+                        */
+                       if (nextdev == NULL) {
+                               /*
+                                * Yes - we have to put the new entry
+                                * after "prevdev".
+                                */
+                               break;
+                       }
+
+                       /*
+                        * Is the new interface's figure of merit less
+                        * than the next interface's figure of merit,
+                        * meaning that the new interface is better
+                        * than the next interface?
+                        */
+                       nextdev_figure_of_merit = get_figure_of_merit(nextdev);
+                       if (this_figure_of_merit < nextdev_figure_of_merit) {
+                               /*
+                                * Yes - we should put the new entry
+                                * before "nextdev", i.e. after "prevdev".
+                                */
+                               break;
+                       }
+
+                       prevdev = nextdev;
                }
+
+               /*
+                * Insert before "nextdev".
+                */
+               curdev->next = nextdev;
+
+               /*
+                * Insert after "prevdev" - unless "prevdev" is null,
+                * in which case this is the first interface.
+                */
+               if (prevdev == NULL) {
+                       /*
+                        * This is the first interface.  Pass back a
+                        * pointer to it, and put "curdev" before
+                        * "nextdev".
+                        */
+                       *alldevs = curdev;
+               } else
+                       prevdev->next = curdev;
        }
-       if (mp == NULL) {
-               (void)strlcpy(errbuf, "no suitable device found",
-                   PCAP_ERRBUF_SIZE);
-#ifdef HAVE_FREEIFADDRS
-               freeifaddrs(ifap);
+
+       *curdev_ret = curdev;
+       return (0);
+}
+
+/*
+ * Try to get a description for a given device.
+ * Returns a mallocated description if it could and NULL if it couldn't.
+ *
+ * XXX - on FreeBSDs that support it, should it get the sysctl named
+ * "dev.{adapter family name}.{adapter unit}.%desc" to get a description
+ * of the adapter?  Note that "dev.an.0.%desc" is "Aironet PC4500/PC4800"
+ * with my Cisco 350 card, so the name isn't entirely descriptive.  The
+ * "dev.an.0.%pnpinfo" has a better description, although one might argue
+ * that the problem is really a driver bug - if it can find out that it's
+ * a Cisco 340 or 350, rather than an old Aironet card, it should use
+ * that in the description.
+ *
+ * Do NetBSD, DragonflyBSD, or OpenBSD support this as well?  FreeBSD
+ * and OpenBSD let you get a description, but it's not generated by the OS,
+ * it's set with another ioctl that ifconfig supports; we use that to get
+ * a description in FreeBSD and OpenBSD, but if there is no such
+ * description available, it still might be nice to get some description
+ * string based on the device type or something such as that.
+ *
+ * In OS X, the System Configuration framework can apparently return
+ * names in 10.4 and later.
+ *
+ * It also appears that freedesktop.org's HAL offers an "info.product"
+ * string, but the HAL specification says it "should not be used in any
+ * UI" and "subsystem/capability specific properties" should be used
+ * instead and, in any case, I think HAL is being deprecated in
+ * favor of other stuff such as DeviceKit.  DeviceKit doesn't appear
+ * to have any obvious product information for devices, but maybe
+ * I haven't looked hard enough.
+ *
+ * Using the System Configuration framework, or HAL, or DeviceKit, or
+ * whatever, would require that libpcap applications be linked with
+ * the frameworks/libraries in question.  That shouldn't be a problem
+ * for programs linking with the shared version of libpcap (unless
+ * you're running on AIX - which I think is the only UN*X that doesn't
+ * support linking a shared library with other libraries on which it
+ * depends, and having an executable linked only with the first shared
+ * library automatically pick up the other libraries when started -
+ * and using HAL or whatever).  Programs linked with the static
+ * version of libpcap would have to use pcap-config with the --static
+ * flag in order to get the right linker flags in order to pick up
+ * the additional libraries/frameworks; those programs need that anyway
+ * for libpcap 1.1 and beyond on Linux, as, by default, it requires
+ * -lnl.
+ *
+ * Do any other UN*Xes, or desktop environments support getting a
+ * description?
+ */
+static char *
+get_if_description(const char *name)
+{
+#ifdef SIOCGIFDESCR
+       char *description = NULL;
+       int s;
+       struct ifreq ifrdesc;
+#ifndef IFDESCRSIZE
+       size_t descrlen = 64;
 #else
-               free(ifap);
-#endif
-               return (NULL);
+       size_t descrlen = IFDESCRSIZE;
+#endif /* IFDESCRSIZE */
+
+       /*
+        * Get the description for the interface.
+        */
+       memset(&ifrdesc, 0, sizeof ifrdesc);
+       strlcpy(ifrdesc.ifr_name, name, sizeof ifrdesc.ifr_name);
+       s = socket(AF_INET, SOCK_DGRAM, 0);
+       if (s >= 0) {
+#ifdef __FreeBSD__
+               /*
+                * On FreeBSD, if the buffer isn't big enough for the
+                * description, the ioctl succeeds, but the description
+                * isn't copied, ifr_buffer.length is set to the description
+                * length, and ifr_buffer.buffer is set to NULL.
+                */
+               for (;;) {
+                       free(description);
+                       if ((description = malloc(descrlen)) != NULL) {
+                               ifrdesc.ifr_buffer.buffer = description;
+                               ifrdesc.ifr_buffer.length = descrlen;
+                               if (ioctl(s, SIOCGIFDESCR, &ifrdesc) == 0) {
+                                       if (ifrdesc.ifr_buffer.buffer ==
+                                           description)
+                                               break;
+                                       else
+                                               descrlen = ifrdesc.ifr_buffer.length;
+                               } else {
+                                       /*
+                                        * Failed to get interface description.
+                                        */
+                                       free(description);
+                                       description = NULL;
+                                       break;
+                               }
+                       } else
+                               break;
+               }
+#else /* __FreeBSD__ */
+               /*
+                * The only other OS that currently supports
+                * SIOCGIFDESCR is OpenBSD, and it has no way
+                * to get the description length - it's clamped
+                * to a maximum of IFDESCRSIZE.
+                */
+               if ((description = malloc(descrlen)) != NULL) {
+                       ifrdesc.ifr_data = (caddr_t)description;
+                       if (ioctl(s, SIOCGIFDESCR, &ifrdesc) != 0) {
+                               /*
+                                * Failed to get interface description.
+                                */
+                               free(description);
+                               description = NULL;
+                       }
+               }
+#endif /* __FreeBSD__ */
+               close(s);
+               if (description != NULL && strlen(description) == 0) {
+                       free(description);
+                       description = NULL;
+               }
        }
 
-       (void)strlcpy(device, mp->ifa_name, sizeof(device));
-#ifdef HAVE_FREEIFADDRS
-       freeifaddrs(ifap);
-#else
-       free(ifap);
-#endif
-       return (device);
-#else
-       register int fd, minunit, n;
-       register char *cp;
-       register struct ifreq *ifrp, *ifend, *ifnext, *mp;
-       struct ifconf ifc;
-       char *buf;
-       struct ifreq ifr;
-       static char device[sizeof(ifrp->ifr_name) + 1];
-       unsigned buf_size;
+       return (description);
+#else /* SIOCGIFDESCR */
+       return (NULL);
+#endif /* SIOCGIFDESCR */
+}
 
-       fd = socket(AF_INET, SOCK_DGRAM, 0);
-       if (fd < 0) {
-               (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
-                   "socket: %s", pcap_strerror(errno));
-               return (NULL);
+/*
+ * Try to get a description for a given device, and then look for that
+ * device in the specified list of devices.
+ *
+ * If we find it, then, if the specified address isn't null, add it to
+ * the list of addresses for the device and return 0.
+ *
+ * If we don't find it, check whether we can open it:
+ *
+ *     If that fails with PCAP_ERROR_NO_SUCH_DEVICE or
+ *     PCAP_ERROR_IFACE_NOT_UP, don't attempt to add an entry for
+ *     it, as that probably means it exists but doesn't support
+ *     packet capture.
+ *
+ *     Otherwise, attempt to add an entry for it, with the specified
+ *     ifnet flags and description, and, if that succeeds, add the
+ *     specified address to its list of addresses if that address is
+ *     non-null, set *curdev_ret to point to the new entry, and
+ *     return 0, otherwise return PCAP_ERROR and set errbuf to an
+ *     error message.
+ *
+ * (We can get called with a null address because we might get a list
+ * of interface name/address combinations from the underlying OS, with
+ * the address being absent in some cases, rather than a list of
+ * interfaces with each interface having a list of addresses, so this
+ * call may be the only call made to add to the list, and we want to
+ * add interfaces even if they have no addresses.)
+ */
+int
+add_addr_to_iflist(pcap_if_t **alldevs, const char *name, u_int flags,
+    struct sockaddr *addr, size_t addr_size,
+    struct sockaddr *netmask, size_t netmask_size,
+    struct sockaddr *broadaddr, size_t broadaddr_size,
+    struct sockaddr *dstaddr, size_t dstaddr_size,
+    char *errbuf)
+{
+       char *description;
+       pcap_if_t *curdev;
+
+       description = get_if_description(name);
+       if (add_or_find_if(&curdev, alldevs, name, flags, description,
+           errbuf) == -1) {
+               free(description);
+               /*
+                * Error - give up.
+                */
+               return (-1);
+       }
+       free(description);
+       if (curdev == NULL) {
+               /*
+                * Device wasn't added because it can't be opened.
+                * Not a fatal error.
+                */
+               return (0);
        }
 
-       buf_size = 8192;
+       if (addr == NULL) {
+               /*
+                * There's no address to add; this entry just meant
+                * "here's a new interface".
+                */
+               return (0);
+       }
 
-       for (;;) {
-               buf = malloc (buf_size);
-               if (buf == NULL) {
-                       close (fd);
-                       (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
-                           "out of memory");
-                       return (NULL);
+       /*
+        * "curdev" is an entry for this interface, and we have an
+        * address for it; add an entry for that address to the
+        * interface's list of addresses.
+        *
+        * Allocate the new entry and fill it in.
+        */
+       return (add_addr_to_dev(curdev, addr, addr_size, netmask,
+           netmask_size, broadaddr, broadaddr_size, dstaddr,
+           dstaddr_size, errbuf));
+}
+
+/*
+ * Add an entry to the list of addresses for an interface.
+ * "curdev" is the entry for that interface.
+ * If this is the first IP address added to the interface, move it
+ * in the list as appropriate.
+ */
+int
+add_addr_to_dev(pcap_if_t *curdev,
+    struct sockaddr *addr, size_t addr_size,
+    struct sockaddr *netmask, size_t netmask_size,
+    struct sockaddr *broadaddr, size_t broadaddr_size,
+    struct sockaddr *dstaddr, size_t dstaddr_size,
+    char *errbuf)
+{
+       pcap_addr_t *curaddr, *prevaddr, *nextaddr;
+
+       curaddr = malloc(sizeof(pcap_addr_t));
+       if (curaddr == NULL) {
+               (void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
+                   "malloc: %s", pcap_strerror(errno));
+               return (-1);
+       }
+
+       curaddr->next = NULL;
+       if (addr != NULL) {
+               curaddr->addr = dup_sockaddr(addr, addr_size);
+               if (curaddr->addr == NULL) {
+                       (void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
+                           "malloc: %s", pcap_strerror(errno));
+                       free(curaddr);
+                       return (-1);
                }
+       } else
+               curaddr->addr = NULL;
 
-               ifc.ifc_len = buf_size;
-               ifc.ifc_buf = buf;
-               memset (buf, 0, buf_size);
-               if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0
-                   && errno != EINVAL) {
-                       free (buf);
-                       (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
-                           "SIOCGIFCONF: %s", pcap_strerror(errno));
-                       (void)close(fd);
-                       return (NULL);
+       if (netmask != NULL) {
+               curaddr->netmask = dup_sockaddr(netmask, netmask_size);
+               if (curaddr->netmask == NULL) {
+                       (void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
+                           "malloc: %s", pcap_strerror(errno));
+                       if (curaddr->addr != NULL)
+                               free(curaddr->addr);
+                       free(curaddr);
+                       return (-1);
                }
-               if (ifc.ifc_len < buf_size)
+       } else
+               curaddr->netmask = NULL;
+
+       if (broadaddr != NULL) {
+               curaddr->broadaddr = dup_sockaddr(broadaddr, broadaddr_size);
+               if (curaddr->broadaddr == NULL) {
+                       (void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
+                           "malloc: %s", pcap_strerror(errno));
+                       if (curaddr->netmask != NULL)
+                               free(curaddr->netmask);
+                       if (curaddr->addr != NULL)
+                               free(curaddr->addr);
+                       free(curaddr);
+                       return (-1);
+               }
+       } else
+               curaddr->broadaddr = NULL;
+
+       if (dstaddr != NULL) {
+               curaddr->dstaddr = dup_sockaddr(dstaddr, dstaddr_size);
+               if (curaddr->dstaddr == NULL) {
+                       (void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
+                           "malloc: %s", pcap_strerror(errno));
+                       if (curaddr->broadaddr != NULL)
+                               free(curaddr->broadaddr);
+                       if (curaddr->netmask != NULL)
+                               free(curaddr->netmask);
+                       if (curaddr->addr != NULL)
+                               free(curaddr->addr);
+                       free(curaddr);
+                       return (-1);
+               }
+       } else
+               curaddr->dstaddr = NULL;
+
+       /*
+        * Find the end of the list of addresses.
+        */
+       for (prevaddr = curdev->addresses; prevaddr != NULL; prevaddr = nextaddr) {
+               nextaddr = prevaddr->next;
+               if (nextaddr == NULL) {
+                       /*
+                        * This is the end of the list.
+                        */
                        break;
-               free (buf);
-               buf_size *= 2;
+               }
        }
 
-       ifrp = (struct ifreq *)buf;
-       ifend = (struct ifreq *)(buf + ifc.ifc_len);
+       if (prevaddr == NULL) {
+               /*
+                * The list was empty; this is the first member.
+                */
+               curdev->addresses = curaddr;
+       } else {
+               /*
+                * "prevaddr" is the last member of the list; append
+                * this member to it.
+                */
+               prevaddr->next = curaddr;
+       }
 
-       mp = NULL;
-       minunit = 666;
-       for (; ifrp < ifend; ifrp = ifnext) {
-               const char *endcp;
+       return (0);
+}
+
+/*
+ * Look for a given device in the specified list of devices.
+ *
+ * If we find it, return 0.
+ *
+ * If we don't find it, check whether we can open it:
+ *
+ *     If that fails with PCAP_ERROR_NO_SUCH_DEVICE or
+ *     PCAP_ERROR_IFACE_NOT_UP, don't attempt to add an entry for
+ *     it, as that probably means it exists but doesn't support
+ *     packet capture.
+ *
+ *     Otherwise, attempt to add an entry for it, with the specified
+ *     ifnet flags and description, and, if that succeeds, return 0
+ *     and set *curdev_ret to point to the new entry, otherwise
+ *     return PCAP_ERROR and set errbuf to an error message.
+ */
+int
+pcap_add_if(pcap_if_t **devlist, const char *name, u_int flags,
+    const char *description, char *errbuf)
+{
+       pcap_if_t *curdev;
+
+       return (add_or_find_if(&curdev, devlist, name, flags, description,
+           errbuf));
+}
+
+
+/*
+ * Free a list of interfaces.
+ */
+void
+pcap_freealldevs(pcap_if_t *alldevs)
+{
+       pcap_if_t *curdev, *nextdev;
+       pcap_addr_t *curaddr, *nextaddr;
+
+       for (curdev = alldevs; curdev != NULL; curdev = nextdev) {
+               nextdev = curdev->next;
 
-#ifdef HAVE_SOCKADDR_SA_LEN
-               n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
-               if (n < sizeof(*ifrp))
-                       ifnext = ifrp + 1;
-               else
-                       ifnext = (struct ifreq *)((char *)ifrp + n);
-               if (ifrp->ifr_addr.sa_family != AF_INET)
-                       continue;
-#else
-               ifnext = ifrp + 1;
-#endif
                /*
-                * Need a template to preserve address info that is
-                * used below to locate the next entry.  (Otherwise,
-                * SIOCGIFFLAGS stomps over it because the requests
-                * are returned in a union.)
+                * Free all addresses.
                 */
-               strncpy(ifr.ifr_name, ifrp->ifr_name, sizeof(ifr.ifr_name));
-               if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) {
-                       if (errno == ENXIO)
-                               continue;
-                       (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
-                           "SIOCGIFFLAGS: %.*s: %s",
-                           (int)sizeof(ifr.ifr_name), ifr.ifr_name,
-                           pcap_strerror(errno));
-                       (void)close(fd);
-                       free (buf);
-                       return (NULL);
+               for (curaddr = curdev->addresses; curaddr != NULL; curaddr = nextaddr) {
+                       nextaddr = curaddr->next;
+                       if (curaddr->addr)
+                               free(curaddr->addr);
+                       if (curaddr->netmask)
+                               free(curaddr->netmask);
+                       if (curaddr->broadaddr)
+                               free(curaddr->broadaddr);
+                       if (curaddr->dstaddr)
+                               free(curaddr->dstaddr);
+                       free(curaddr);
                }
 
-               /* Must be up and not the loopback */
-               if ((ifr.ifr_flags & IFF_UP) == 0 || ISLOOPBACK(&ifr))
-                       continue;
+               /*
+                * Free the name string.
+                */
+               free(curdev->name);
 
-               endcp = ifrp->ifr_name + strlen(ifrp->ifr_name);
-               for (cp = ifrp->ifr_name; cp < endcp && !isdigit(*cp); ++cp)
-                       continue;
-               
-               if (isdigit (*cp)) {
-                       n = atoi(cp);
-               } else {
-                       n = 0;
-               }
-               if (n < minunit) {
-                       minunit = n;
-                       mp = ifrp;
-               }
+               /*
+                * Free the description string, if any.
+                */
+               if (curdev->description != NULL)
+                       free(curdev->description);
+
+               /*
+                * Free the interface.
+                */
+               free(curdev);
        }
-       (void)close(fd);
-       if (mp == NULL) {
+}
+
+#if !defined(_WIN32) && !defined(MSDOS)
+
+/*
+ * Return the name of a network interface attached to the system, or NULL
+ * if none can be found.  The interface must be configured up; the
+ * lowest unit number is preferred; loopback is ignored.
+ */
+char *
+pcap_lookupdev(errbuf)
+       register char *errbuf;
+{
+       pcap_if_t *alldevs;
+/* for old BSD systems, including bsdi3 */
+#ifndef IF_NAMESIZE
+#define IF_NAMESIZE IFNAMSIZ
+#endif
+       static char device[IF_NAMESIZE + 1];
+       char *ret;
+
+       if (pcap_findalldevs(&alldevs, errbuf) == -1)
+               return (NULL);
+
+       if (alldevs == NULL || (alldevs->flags & PCAP_IF_LOOPBACK)) {
+               /*
+                * There are no devices on the list, or the first device
+                * on the list is a loopback device, which means there
+                * are no non-loopback devices on the list.  This means
+                * we can't return any device.
+                *
+                * XXX - why not return a loopback device?  If we can't
+                * capture on it, it won't be on the list, and if it's
+                * on the list, there aren't any non-loopback devices,
+                * so why not just supply it as the default device?
+                */
                (void)strlcpy(errbuf, "no suitable device found",
                    PCAP_ERRBUF_SIZE);
-               free(buf);
-               return (NULL);
+               ret = NULL;
+       } else {
+               /*
+                * Return the name of the first device on the list.
+                */
+               (void)strlcpy(device, alldevs->name, sizeof(device));
+               ret = device;
        }
 
-       (void)strlcpy(device, mp->ifr_name, sizeof(device));
-       free(buf);
-       return (device);
-#endif
+       pcap_freealldevs(alldevs);
+       return (ret);
 }
 
 int
 pcap_lookupnet(device, netp, maskp, errbuf)
-       register char *device;
+       register const char *device;
        register bpf_u_int32 *netp, *maskp;
        register char *errbuf;
 {
        register int fd;
-       register struct sockaddr_in *sin;
+       register struct sockaddr_in *sin4;
        struct ifreq ifr;
 
+       /*
+        * The pseudo-device "any" listens on all interfaces and therefore
+        * has the network address and -mask "0.0.0.0" therefore catching
+        * all traffic. Using NULL for the interface is the same as "any".
+        */
+       if (!device || strcmp(device, "any") == 0
+#ifdef HAVE_DAG_API
+           || strstr(device, "dag") != NULL
+#endif
+#ifdef HAVE_SEPTEL_API
+           || strstr(device, "septel") != NULL
+#endif
+#ifdef PCAP_SUPPORT_BT
+           || strstr(device, "bluetooth") != NULL
+#endif
+#ifdef PCAP_SUPPORT_USB
+           || strstr(device, "usbmon") != NULL
+#endif
+#ifdef HAVE_SNF_API
+           || strstr(device, "snf") != NULL
+#endif
+           ) {
+               *netp = *maskp = 0;
+               return 0;
+       }
+
        fd = socket(AF_INET, SOCK_DGRAM, 0);
        if (fd < 0) {
-               (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "socket: %s",
+               (void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE, "socket: %s",
                    pcap_strerror(errno));
                return (-1);
        }
@@ -279,29 +924,35 @@ pcap_lookupnet(device, netp, maskp, errbuf)
        /* XXX Work around Linux kernel bug */
        ifr.ifr_addr.sa_family = AF_INET;
 #endif
-       (void)strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
+       (void)strlcpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
        if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0) {
                if (errno == EADDRNOTAVAIL) {
-                       (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
+                       (void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
                            "%s: no IPv4 address assigned", device);
                } else {
-                       (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
+                       (void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
                            "SIOCGIFADDR: %s: %s",
                            device, pcap_strerror(errno));
                }
                (void)close(fd);
                return (-1);
        }
-       sin = (struct sockaddr_in *)&ifr.ifr_addr;
-       *netp = sin->sin_addr.s_addr;
+       sin4 = (struct sockaddr_in *)&ifr.ifr_addr;
+       *netp = sin4->sin_addr.s_addr;
+       memset(&ifr, 0, sizeof(ifr));
+#ifdef linux
+       /* XXX Work around Linux kernel bug */
+       ifr.ifr_addr.sa_family = AF_INET;
+#endif
+       (void)strlcpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
        if (ioctl(fd, SIOCGIFNETMASK, (char *)&ifr) < 0) {
-               (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
+               (void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
                    "SIOCGIFNETMASK: %s: %s", device, pcap_strerror(errno));
                (void)close(fd);
                return (-1);
        }
        (void)close(fd);
-       *maskp = sin->sin_addr.s_addr;
+       *maskp = sin4->sin_addr.s_addr;
        if (*maskp == 0) {
                if (IN_CLASSA(*netp))
                        *maskp = IN_CLASSA_NET;
@@ -310,7 +961,7 @@ pcap_lookupnet(device, netp, maskp, errbuf)
                else if (IN_CLASSC(*netp))
                        *maskp = IN_CLASSC_NET;
                else {
-                       (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
+                       (void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
                            "inet class for 0x%x unknown", *netp);
                        return (-1);
                }
@@ -318,3 +969,139 @@ pcap_lookupnet(device, netp, maskp, errbuf)
        *netp &= *maskp;
        return (0);
 }
+
+#elif defined(_WIN32)
+
+/*
+ * Return the name of a network interface attached to the system, or NULL
+ * if none can be found.  The interface must be configured up; the
+ * lowest unit number is preferred; loopback is ignored.
+ *
+ * In the best of all possible worlds, this would be the same as on
+ * UN*X, but there may be software that expects this to return a
+ * full list of devices after the first device.
+ */
+char *
+pcap_lookupdev(errbuf)
+       register char *errbuf;
+{
+       DWORD dwVersion;
+       DWORD dwWindowsMajorVersion;
+       char our_errbuf[PCAP_ERRBUF_SIZE+1];
+
+       dwVersion = GetVersion();       /* get the OS version */
+       dwWindowsMajorVersion = (DWORD)(LOBYTE(LOWORD(dwVersion)));
+
+       if (dwVersion >= 0x80000000 && dwWindowsMajorVersion >= 4) {
+               /*
+                * Windows 95, 98, ME.
+                */
+               ULONG NameLength = 8192;
+               static char AdaptersName[8192];
+
+               if (PacketGetAdapterNames(AdaptersName,&NameLength) )
+                       return (AdaptersName);
+               else
+                       return NULL;
+       } else {
+               /*
+                * Windows NT (NT 4.0, W2K, WXP). Convert the names to UNICODE for backward compatibility
+                */
+               ULONG NameLength = 8192;
+               static WCHAR AdaptersName[8192];
+               char *tAstr;
+               WCHAR *tUstr;
+               WCHAR *TAdaptersName = (WCHAR*)malloc(8192 * sizeof(WCHAR));
+               int NAdapts = 0;
+
+               if(TAdaptersName == NULL)
+               {
+                       (void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE, "memory allocation failure");
+                       return NULL;
+               }
+
+               if ( !PacketGetAdapterNames((PTSTR)TAdaptersName,&NameLength) )
+               {
+                       pcap_win32_err_to_str(GetLastError(), our_errbuf);
+                       (void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
+                               "PacketGetAdapterNames: %s", our_errbuf);
+                       free(TAdaptersName);
+                       return NULL;
+               }
+
+
+               tAstr = (char*)TAdaptersName;
+               tUstr = (WCHAR*)AdaptersName;
+
+               /*
+                * Convert and copy the device names
+                */
+               while(sscanf(tAstr, "%S", tUstr) > 0)
+               {
+                       tAstr += strlen(tAstr) + 1;
+                       tUstr += wcslen(tUstr) + 1;
+                       NAdapts ++;
+               }
+
+               tAstr++;
+               *tUstr = 0;
+               tUstr++;
+
+               /*
+                * Copy the descriptions
+                */
+               while(NAdapts--)
+               {
+                       char* tmp = (char*)tUstr;
+                       strcpy(tmp, tAstr);
+                       tmp += strlen(tAstr) + 1;
+                       tUstr = (WCHAR*)tmp;
+                       tAstr += strlen(tAstr) + 1;
+               }
+
+               free(TAdaptersName);
+               return (char *)(AdaptersName);
+       }
+}
+
+
+int
+pcap_lookupnet(device, netp, maskp, errbuf)
+       register const char *device;
+       register bpf_u_int32 *netp, *maskp;
+       register char *errbuf;
+{
+       /*
+        * We need only the first IPv4 address, so we must scan the array returned by PacketGetNetInfo()
+        * in order to skip non IPv4 (i.e. IPv6 addresses)
+        */
+       npf_if_addr if_addrs[MAX_NETWORK_ADDRESSES];
+       LONG if_addr_size = 1;
+       struct sockaddr_in *t_addr;
+       unsigned int i;
+
+       if (!PacketGetNetInfoEx((void *)device, if_addrs, &if_addr_size)) {
+               *netp = *maskp = 0;
+               return (0);
+       }
+
+       for(i=0; i<MAX_NETWORK_ADDRESSES; i++)
+       {
+               if(if_addrs[i].IPAddress.ss_family == AF_INET)
+               {
+                       t_addr = (struct sockaddr_in *) &(if_addrs[i].IPAddress);
+                       *netp = t_addr->sin_addr.S_un.S_addr;
+                       t_addr = (struct sockaddr_in *) &(if_addrs[i].SubnetMask);
+                       *maskp = t_addr->sin_addr.S_un.S_addr;
+
+                       *netp &= *maskp;
+                       return (0);
+               }
+
+       }
+
+       *netp = *maskp = 0;
+       return (0);
+}
+
+#endif /* !_WIN32 && !MSDOS */