1 /* -*- Mode: c; tab-width: 8; indent-tabs-mode: 1; c-basic-offset: 8; -*- */
3 * Copyright (c) 1994, 1995, 1996, 1997, 1998
4 * The Regents of the University of California. All rights reserved.
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16 * This product includes software developed by the Computer Systems
17 * Engineering Group at Lawrence Berkeley Laboratory.
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36 static const char rcsid[] _U_ =
37 "@(#) $Header: /tcpdump/master/libpcap/inet.c,v 1.79 2008-04-20 18:19:02 guy Exp $ (LBL)";
45 #include <pcap-stdinc.h>
48 #include <sys/param.h>
52 #include <sys/ioctl.h>
53 #include <sys/socket.h>
54 #ifdef HAVE_SYS_SOCKIO_H
55 #include <sys/sockio.h>
58 struct mbuf; /* Squelch compiler warnings on some platforms for */
59 struct rtentry; /* declarations in <net/if.h> */
61 #include <netinet/in.h>
70 #if !defined(WIN32) && !defined(__BORLANDC__)
72 #endif /* !WIN32 && !__BORLANDC__ */
76 #define INT_MAX 2147483647
81 #ifdef HAVE_OS_PROTO_H
85 /* Not all systems have IFF_LOOPBACK */
87 #define ISLOOPBACK(name, flags) ((flags) & IFF_LOOPBACK)
89 #define ISLOOPBACK(name, flags) ((name)[0] == 'l' && (name)[1] == 'o' && \
90 (isdigit((unsigned char)((name)[2])) || (name)[2] == '\0'))
94 dup_sockaddr(struct sockaddr *sa, size_t sa_length)
96 struct sockaddr *newsa;
98 if ((newsa = malloc(sa_length)) == NULL)
100 return (memcpy(newsa, sa, sa_length));
104 get_instance(const char *name)
106 const char *cp, *endcp;
109 if (strcmp(name, "any") == 0) {
111 * Give the "any" device an artificially high instance
112 * number, so it shows up after all other non-loopback
118 endcp = name + strlen(name);
119 for (cp = name; cp < endcp && !isdigit((unsigned char)*cp); ++cp)
122 if (isdigit((unsigned char)*cp))
130 add_or_find_if(pcap_if_t **curdev_ret, pcap_if_t **alldevs, const char *name,
131 u_int flags, const char *description, char *errbuf)
134 pcap_if_t *curdev, *prevdev, *nextdev;
138 * Is there already an entry in the list for this interface?
140 for (curdev = *alldevs; curdev != NULL; curdev = curdev->next) {
141 if (strcmp(name, curdev->name) == 0)
142 break; /* yes, we found it */
145 if (curdev == NULL) {
147 * No, we didn't find it.
149 * Can we open this interface for live capture?
151 * We do this check so that interfaces that are
152 * supplied by the interface enumeration mechanism
153 * we're using but that don't support packet capture
154 * aren't included in the list. Loopback interfaces
155 * on Solaris are an example of this; we don't just
156 * omit loopback interfaces on all platforms because
157 * you *can* capture on loopback interfaces on some
160 * On OS X, we don't do this check if the device
161 * name begins with "wlt"; at least some versions
162 * of OS X offer monitor mode capturing by having
163 * a separate "monitor mode" device for each wireless
164 * adapter, rather than by implementing the ioctls
165 * that {Free,Net,Open,DragonFly}BSD provide.
166 * Opening that device puts the adapter into monitor
167 * mode, which, at least for some adapters, causes
168 * them to deassociate from the network with which
169 * they're associated.
171 * Instead, we try to open the corresponding "en"
172 * device (so that we don't end up with, for users
173 * without sufficient privilege to open capture
174 * devices, a list of adapters that only includes
178 if (strncmp(name, "wlt", 3) == 0) {
183 * Try to allocate a buffer for the "en"
186 en_name_len = strlen(name) - 1;
187 en_name = malloc(en_name_len + 1);
188 if (en_name == NULL) {
189 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
190 "malloc: %s", pcap_strerror(errno));
193 strcpy(en_name, "en");
194 strcat(en_name, name + 3);
195 p = pcap_open_live(en_name, 68, 0, 0, errbuf);
199 p = pcap_open_live(name, 68, 0, 0, errbuf);
202 * No. Don't bother including it.
203 * Don't treat this as an error, though.
211 * Yes, we can open it.
212 * Allocate a new entry.
214 curdev = malloc(sizeof(pcap_if_t));
215 if (curdev == NULL) {
216 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
217 "malloc: %s", pcap_strerror(errno));
225 curdev->name = strdup(name);
226 if (curdev->name == NULL) {
227 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
228 "malloc: %s", pcap_strerror(errno));
232 if (description != NULL) {
234 * We have a description for this interface.
236 curdev->description = strdup(description);
237 if (curdev->description == NULL) {
238 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
239 "malloc: %s", pcap_strerror(errno));
248 curdev->description = NULL;
250 curdev->addresses = NULL; /* list starts out as empty */
252 if (ISLOOPBACK(name, flags))
253 curdev->flags |= PCAP_IF_LOOPBACK;
256 * Add it to the list, in the appropriate location.
257 * First, get the instance number of this interface.
259 this_instance = get_instance(name);
262 * Now look for the last interface with an instance number
263 * less than or equal to the new interface's instance
264 * number - except that non-loopback interfaces are
265 * arbitrarily treated as having interface numbers less
266 * than those of loopback interfaces, so the loopback
267 * interfaces are put at the end of the list.
269 * We start with "prevdev" being NULL, meaning we're before
270 * the first element in the list.
275 * Get the interface after this one.
277 if (prevdev == NULL) {
279 * The next element is the first element.
283 nextdev = prevdev->next;
286 * Are we at the end of the list?
288 if (nextdev == NULL) {
290 * Yes - we have to put the new entry
297 * Is the new interface a non-loopback interface
298 * and the next interface a loopback interface?
300 if (!(curdev->flags & PCAP_IF_LOOPBACK) &&
301 (nextdev->flags & PCAP_IF_LOOPBACK)) {
303 * Yes, we should put the new entry
304 * before "nextdev", i.e. after "prevdev".
310 * Is the new interface's instance number less
311 * than the next interface's instance number,
312 * and is it the case that the new interface is a
313 * non-loopback interface or the next interface is
314 * a loopback interface?
316 * (The goal of both loopback tests is to make
317 * sure that we never put a loopback interface
318 * before any non-loopback interface and that we
319 * always put a non-loopback interface before all
320 * loopback interfaces.)
322 if (this_instance < get_instance(nextdev->name) &&
323 (!(curdev->flags & PCAP_IF_LOOPBACK) ||
324 (nextdev->flags & PCAP_IF_LOOPBACK))) {
326 * Yes - we should put the new entry
327 * before "nextdev", i.e. after "prevdev".
336 * Insert before "nextdev".
338 curdev->next = nextdev;
341 * Insert after "prevdev" - unless "prevdev" is null,
342 * in which case this is the first interface.
344 if (prevdev == NULL) {
346 * This is the first interface. Pass back a
347 * pointer to it, and put "curdev" before
352 prevdev->next = curdev;
355 *curdev_ret = curdev;
360 * XXX - on FreeBSDs that support it, should it get the sysctl named
361 * "dev.{adapter family name}.{adapter unit}.%desc" to get a description
362 * of the adapter? Note that "dev.an.0.%desc" is "Aironet PC4500/PC4800"
363 * with my Cisco 350 card, so the name isn't entirely descriptive. The
364 * "dev.an.0.%pnpinfo" has a better description, although one might argue
365 * that the problem is really a driver bug - if it can find out that it's
366 * a Cisco 340 or 350, rather than an old Aironet card, it should use
367 * that in the description.
369 * Do NetBSD, DragonflyBSD, or OpenBSD support this as well? FreeBSD
370 * and OpenBSD let you get a description, but it's not generated by the OS,
371 * it's set with another ioctl that ifconfig supports; we use that to get
372 * a description in FreeBSD and OpenBSD, but if there is no such
373 * description available, it still might be nice to get some description
374 * string based on the device type or something such as that.
376 * In OS X, the System Configuration framework can apparently return
377 * names in 10.4 and later.
379 * It also appears that freedesktop.org's HAL offers an "info.product"
380 * string, but the HAL specification says it "should not be used in any
381 * UI" and "subsystem/capability specific properties" should be used
382 * instead and, in any case, I think HAL is being deprecated in
383 * favor of other stuff such as DeviceKit. DeviceKit doesn't appear
384 * to have any obvious product information for devices, but maybe
385 * I haven't looked hard enough.
387 * Using the System Configuration framework, or HAL, or DeviceKit, or
388 * whatever, would require that libpcap applications be linked with
389 * the frameworks/libraries in question. That shouldn't be a problem
390 * for programs linking with the shared version of libpcap (unless
391 * you're running on AIX - which I think is the only UN*X that doesn't
392 * support linking a shared library with other libraries on which it
393 * depends, and having an executable linked only with the first shared
394 * library automatically pick up the other libraries when started -
395 * and using HAL or whatever). Programs linked with the static
396 * version of libpcap would have to use pcap-config with the --static
397 * flag in order to get the right linker flags in order to pick up
398 * the additional libraries/frameworks; those programs need that anyway
399 * for libpcap 1.1 and beyond on Linux, as, by default, it requires
402 * Do any other UN*Xes, or desktop environments support getting a
406 add_addr_to_iflist(pcap_if_t **alldevs, const char *name, u_int flags,
407 struct sockaddr *addr, size_t addr_size,
408 struct sockaddr *netmask, size_t netmask_size,
409 struct sockaddr *broadaddr, size_t broadaddr_size,
410 struct sockaddr *dstaddr, size_t dstaddr_size,
414 char *description = NULL;
415 pcap_addr_t *curaddr, *prevaddr, *nextaddr;
418 struct ifreq ifrdesc;
420 size_t descrlen = 64;
422 size_t descrlen = IFDESCRSIZE;
423 #endif /* IFDESCRSIZE */
424 #endif /* SIOCGIFDESCR */
428 * Get the description for the interface.
430 memset(&ifrdesc, 0, sizeof ifrdesc);
431 strlcpy(ifrdesc.ifr_name, name, sizeof ifrdesc.ifr_name);
432 s = socket(AF_INET, SOCK_DGRAM, 0);
436 * On FreeBSD, if the buffer isn't big enough for the
437 * description, the ioctl succeeds, but the description
438 * isn't copied, ifr_buffer.length is set to the description
439 * length, and ifr_buffer.buffer is set to NULL.
443 if ((description = malloc(descrlen)) != NULL) {
444 ifrdesc.ifr_buffer.buffer = description;
445 ifrdesc.ifr_buffer.length = descrlen;
446 if (ioctl(s, SIOCGIFDESCR, &ifrdesc) == 0) {
447 if (ifrdesc.ifr_buffer.buffer ==
451 descrlen = ifrdesc.ifr_buffer.length;
454 * Failed to get interface description.
463 #else /* __FreeBSD__ */
465 * The only other OS that currently supports
466 * SIOCGIFDESCR is OpenBSD, and it has no way
467 * to get the description length - it's clamped
468 * to a maximum of IFDESCRSIZE.
470 if ((description = malloc(descrlen)) != NULL) {
471 ifrdesc.ifr_data = (caddr_t)description;
472 if (ioctl(s, SIOCGIFDESCR, &ifrdesc) != 0) {
474 * Failed to get interface description.
481 #endif /* __FreeBSD__ */
483 if (description != NULL && strlen(description) == 0) {
488 #endif /* SIOCGIFDESCR */
490 if (add_or_find_if(&curdev, alldevs, name, flags, description,
499 if (curdev == NULL) {
501 * Device wasn't added because it can't be opened.
508 * "curdev" is an entry for this interface; add an entry for this
509 * address to its list of addresses.
511 * Allocate the new entry and fill it in.
513 curaddr = malloc(sizeof(pcap_addr_t));
514 if (curaddr == NULL) {
515 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
516 "malloc: %s", pcap_strerror(errno));
520 curaddr->next = NULL;
522 curaddr->addr = dup_sockaddr(addr, addr_size);
523 if (curaddr->addr == NULL) {
524 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
525 "malloc: %s", pcap_strerror(errno));
530 curaddr->addr = NULL;
532 if (netmask != NULL) {
533 curaddr->netmask = dup_sockaddr(netmask, netmask_size);
534 if (curaddr->netmask == NULL) {
535 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
536 "malloc: %s", pcap_strerror(errno));
537 if (curaddr->addr != NULL)
543 curaddr->netmask = NULL;
545 if (broadaddr != NULL) {
546 curaddr->broadaddr = dup_sockaddr(broadaddr, broadaddr_size);
547 if (curaddr->broadaddr == NULL) {
548 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
549 "malloc: %s", pcap_strerror(errno));
550 if (curaddr->netmask != NULL)
551 free(curaddr->netmask);
552 if (curaddr->addr != NULL)
558 curaddr->broadaddr = NULL;
560 if (dstaddr != NULL) {
561 curaddr->dstaddr = dup_sockaddr(dstaddr, dstaddr_size);
562 if (curaddr->dstaddr == NULL) {
563 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
564 "malloc: %s", pcap_strerror(errno));
565 if (curaddr->broadaddr != NULL)
566 free(curaddr->broadaddr);
567 if (curaddr->netmask != NULL)
568 free(curaddr->netmask);
569 if (curaddr->addr != NULL)
575 curaddr->dstaddr = NULL;
578 * Find the end of the list of addresses.
580 for (prevaddr = curdev->addresses; prevaddr != NULL; prevaddr = nextaddr) {
581 nextaddr = prevaddr->next;
582 if (nextaddr == NULL) {
584 * This is the end of the list.
590 if (prevaddr == NULL) {
592 * The list was empty; this is the first member.
594 curdev->addresses = curaddr;
597 * "prevaddr" is the last member of the list; append
600 prevaddr->next = curaddr;
607 pcap_add_if(pcap_if_t **devlist, const char *name, u_int flags,
608 const char *description, char *errbuf)
612 return (add_or_find_if(&curdev, devlist, name, flags, description,
618 * Free a list of interfaces.
621 pcap_freealldevs(pcap_if_t *alldevs)
623 pcap_if_t *curdev, *nextdev;
624 pcap_addr_t *curaddr, *nextaddr;
626 for (curdev = alldevs; curdev != NULL; curdev = nextdev) {
627 nextdev = curdev->next;
630 * Free all addresses.
632 for (curaddr = curdev->addresses; curaddr != NULL; curaddr = nextaddr) {
633 nextaddr = curaddr->next;
636 if (curaddr->netmask)
637 free(curaddr->netmask);
638 if (curaddr->broadaddr)
639 free(curaddr->broadaddr);
640 if (curaddr->dstaddr)
641 free(curaddr->dstaddr);
646 * Free the name string.
651 * Free the description string, if any.
653 if (curdev->description != NULL)
654 free(curdev->description);
657 * Free the interface.
663 #if !defined(WIN32) && !defined(MSDOS)
666 * Return the name of a network interface attached to the system, or NULL
667 * if none can be found. The interface must be configured up; the
668 * lowest unit number is preferred; loopback is ignored.
671 pcap_lookupdev(errbuf)
672 register char *errbuf;
675 /* for old BSD systems, including bsdi3 */
677 #define IF_NAMESIZE IFNAMSIZ
679 static char device[IF_NAMESIZE + 1];
682 if (pcap_findalldevs(&alldevs, errbuf) == -1)
685 if (alldevs == NULL || (alldevs->flags & PCAP_IF_LOOPBACK)) {
687 * There are no devices on the list, or the first device
688 * on the list is a loopback device, which means there
689 * are no non-loopback devices on the list. This means
690 * we can't return any device.
692 * XXX - why not return a loopback device? If we can't
693 * capture on it, it won't be on the list, and if it's
694 * on the list, there aren't any non-loopback devices,
695 * so why not just supply it as the default device?
697 (void)strlcpy(errbuf, "no suitable device found",
702 * Return the name of the first device on the list.
704 (void)strlcpy(device, alldevs->name, sizeof(device));
708 pcap_freealldevs(alldevs);
713 pcap_lookupnet(device, netp, maskp, errbuf)
714 register const char *device;
715 register bpf_u_int32 *netp, *maskp;
716 register char *errbuf;
719 register struct sockaddr_in *sin4;
723 * The pseudo-device "any" listens on all interfaces and therefore
724 * has the network address and -mask "0.0.0.0" therefore catching
725 * all traffic. Using NULL for the interface is the same as "any".
727 if (!device || strcmp(device, "any") == 0
729 || strstr(device, "dag") != NULL
731 #ifdef HAVE_SEPTEL_API
732 || strstr(device, "septel") != NULL
734 #ifdef PCAP_SUPPORT_BT
735 || strstr(device, "bluetooth") != NULL
737 #ifdef PCAP_SUPPORT_USB
738 || strstr(device, "usbmon") != NULL
741 || strstr(device, "snf") != NULL
748 fd = socket(AF_INET, SOCK_DGRAM, 0);
750 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "socket: %s",
751 pcap_strerror(errno));
754 memset(&ifr, 0, sizeof(ifr));
756 /* XXX Work around Linux kernel bug */
757 ifr.ifr_addr.sa_family = AF_INET;
759 (void)strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
760 if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0) {
761 if (errno == EADDRNOTAVAIL) {
762 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
763 "%s: no IPv4 address assigned", device);
765 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
766 "SIOCGIFADDR: %s: %s",
767 device, pcap_strerror(errno));
772 sin4 = (struct sockaddr_in *)&ifr.ifr_addr;
773 *netp = sin4->sin_addr.s_addr;
774 memset(&ifr, 0, sizeof(ifr));
776 /* XXX Work around Linux kernel bug */
777 ifr.ifr_addr.sa_family = AF_INET;
779 (void)strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
780 if (ioctl(fd, SIOCGIFNETMASK, (char *)&ifr) < 0) {
781 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
782 "SIOCGIFNETMASK: %s: %s", device, pcap_strerror(errno));
787 *maskp = sin4->sin_addr.s_addr;
789 if (IN_CLASSA(*netp))
790 *maskp = IN_CLASSA_NET;
791 else if (IN_CLASSB(*netp))
792 *maskp = IN_CLASSB_NET;
793 else if (IN_CLASSC(*netp))
794 *maskp = IN_CLASSC_NET;
796 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
797 "inet class for 0x%x unknown", *netp);
808 * Return the name of a network interface attached to the system, or NULL
809 * if none can be found. The interface must be configured up; the
810 * lowest unit number is preferred; loopback is ignored.
813 pcap_lookupdev(errbuf)
814 register char *errbuf;
817 DWORD dwWindowsMajorVersion;
818 dwVersion = GetVersion(); /* get the OS version */
819 dwWindowsMajorVersion = (DWORD)(LOBYTE(LOWORD(dwVersion)));
821 if (dwVersion >= 0x80000000 && dwWindowsMajorVersion >= 4) {
823 * Windows 95, 98, ME.
825 ULONG NameLength = 8192;
826 static char AdaptersName[8192];
828 if (PacketGetAdapterNames(AdaptersName,&NameLength) )
829 return (AdaptersName);
834 * Windows NT (NT 4.0, W2K, WXP). Convert the names to UNICODE for backward compatibility
836 ULONG NameLength = 8192;
837 static WCHAR AdaptersName[8192];
840 WCHAR *TAdaptersName = (WCHAR*)malloc(8192 * sizeof(WCHAR));
843 if(TAdaptersName == NULL)
845 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "memory allocation failure");
849 if ( !PacketGetAdapterNames((PTSTR)TAdaptersName,&NameLength) )
851 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
852 "PacketGetAdapterNames: %s",
853 pcap_win32strerror());
859 tAstr = (char*)TAdaptersName;
860 tUstr = (WCHAR*)AdaptersName;
863 * Convert and copy the device names
865 while(sscanf(tAstr, "%S", tUstr) > 0)
867 tAstr += strlen(tAstr) + 1;
868 tUstr += wcslen(tUstr) + 1;
877 * Copy the descriptions
881 strcpy((char*)tUstr, tAstr);
882 (char*)tUstr += strlen(tAstr) + 1;;
883 tAstr += strlen(tAstr) + 1;
887 return (char *)(AdaptersName);
893 pcap_lookupnet(device, netp, maskp, errbuf)
894 register const char *device;
895 register bpf_u_int32 *netp, *maskp;
896 register char *errbuf;
899 * We need only the first IPv4 address, so we must scan the array returned by PacketGetNetInfo()
900 * in order to skip non IPv4 (i.e. IPv6 addresses)
902 npf_if_addr if_addrs[MAX_NETWORK_ADDRESSES];
903 LONG if_addr_size = 1;
904 struct sockaddr_in *t_addr;
907 if (!PacketGetNetInfoEx((void *)device, if_addrs, &if_addr_size)) {
912 for(i=0; i<MAX_NETWORK_ADDRESSES; i++)
914 if(if_addrs[i].IPAddress.ss_family == AF_INET)
916 t_addr = (struct sockaddr_in *) &(if_addrs[i].IPAddress);
917 *netp = t_addr->sin_addr.S_un.S_addr;
918 t_addr = (struct sockaddr_in *) &(if_addrs[i].SubnetMask);
919 *maskp = t_addr->sin_addr.S_un.S_addr;
931 #endif /* !WIN32 && !MSDOS */