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[FreeBSD/FreeBSD.git] / contrib / libpcap / inet.c
1 /* -*- Mode: c; tab-width: 8; indent-tabs-mode: 1; c-basic-offset: 8; -*- */
2 /*
3  * Copyright (c) 1994, 1995, 1996, 1997, 1998
4  *      The Regents of the University of California.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. All advertising materials mentioning features or use of this software
15  *    must display the following acknowledgement:
16  *      This product includes software developed by the Computer Systems
17  *      Engineering Group at Lawrence Berkeley Laboratory.
18  * 4. Neither the name of the University nor of the Laboratory may be used
19  *    to endorse or promote products derived from this software without
20  *    specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34
35 #ifndef lint
36 static const char rcsid[] _U_ =
37     "@(#) $Header: /tcpdump/master/libpcap/inet.c,v 1.66.2.1 2005/06/20 21:30:17 guy Exp $ (LBL)";
38 #endif
39
40 #ifdef HAVE_CONFIG_H
41 #include "config.h"
42 #endif
43
44 #ifdef WIN32
45 #include <pcap-stdinc.h>
46 #else /* WIN32 */
47
48 #include <sys/param.h>
49 #ifndef MSDOS
50 #include <sys/file.h>
51 #endif
52 #include <sys/ioctl.h>
53 #include <sys/socket.h>
54 #ifdef HAVE_SYS_SOCKIO_H
55 #include <sys/sockio.h>
56 #endif
57
58 struct mbuf;            /* Squelch compiler warnings on some platforms for */
59 struct rtentry;         /* declarations in <net/if.h> */
60 #include <net/if.h>
61 #include <netinet/in.h>
62 #endif /* WIN32 */
63
64 #include <ctype.h>
65 #include <errno.h>
66 #include <memory.h>
67 #include <stdio.h>
68 #include <stdlib.h>
69 #include <string.h>
70 #if !defined(WIN32) && !defined(__BORLANDC__)
71 #include <unistd.h>
72 #endif /* !WIN32 && !__BORLANDC__ */
73 #ifdef HAVE_LIMITS_H
74 #include <limits.h>
75 #else
76 #define INT_MAX         2147483647
77 #endif
78
79 #include "pcap-int.h"
80
81 #ifdef HAVE_OS_PROTO_H
82 #include "os-proto.h"
83 #endif
84
85 /* Not all systems have IFF_LOOPBACK */
86 #ifdef IFF_LOOPBACK
87 #define ISLOOPBACK(name, flags) ((flags) & IFF_LOOPBACK)
88 #else
89 #define ISLOOPBACK(name, flags) ((name)[0] == 'l' && (name)[1] == 'o' && \
90     (isdigit((unsigned char)((name)[2])) || (name)[2] == '\0'))
91 #endif
92
93 struct sockaddr *
94 dup_sockaddr(struct sockaddr *sa, size_t sa_length)
95 {
96         struct sockaddr *newsa;
97
98         if ((newsa = malloc(sa_length)) == NULL)
99                 return (NULL);
100         return (memcpy(newsa, sa, sa_length));
101 }
102
103 static int
104 get_instance(const char *name)
105 {
106         const char *cp, *endcp;
107         int n;
108
109         if (strcmp(name, "any") == 0) {
110                 /*
111                  * Give the "any" device an artificially high instance
112                  * number, so it shows up after all other non-loopback
113                  * interfaces.
114                  */
115                 return INT_MAX;
116         }
117
118         endcp = name + strlen(name);
119         for (cp = name; cp < endcp && !isdigit((unsigned char)*cp); ++cp)
120                 continue;
121
122         if (isdigit((unsigned char)*cp))
123                 n = atoi(cp);
124         else
125                 n = 0;
126         return (n);
127 }
128
129 int
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)
132 {
133         pcap_t *p;
134         pcap_if_t *curdev, *prevdev, *nextdev;
135         int this_instance;
136
137         /*
138          * Can we open this interface for live capture?
139          *
140          * We do this check so that interfaces that ae supplied
141          * by the interface enumeration mechanism we're using
142          * but that don't support packet capture aren't included
143          * in the list.  An example of this is loopback interfaces
144          * on Solaris; we don't just omit loopback interfaces
145          * becaue you *can* capture on loopback interfaces on some
146          * OSes.
147          */
148         p = pcap_open_live(name, 68, 0, 0, errbuf);
149         if (p == NULL) {
150                 /*
151                  * No.  Don't bother including it.
152                  * Don't treat this as an error, though.
153                  */
154                 *curdev_ret = NULL;
155                 return (0);
156         }
157         pcap_close(p);
158
159         /*
160          * Is there already an entry in the list for this interface?
161          */
162         for (curdev = *alldevs; curdev != NULL; curdev = curdev->next) {
163                 if (strcmp(name, curdev->name) == 0)
164                         break;  /* yes, we found it */
165         }
166         if (curdev == NULL) {
167                 /*
168                  * No, we didn't find it.
169                  * Allocate a new entry.
170                  */
171                 curdev = malloc(sizeof(pcap_if_t));
172                 if (curdev == NULL) {
173                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
174                             "malloc: %s", pcap_strerror(errno));
175                         return (-1);
176                 }
177
178                 /*
179                  * Fill in the entry.
180                  */
181                 curdev->next = NULL;
182                 curdev->name = malloc(strlen(name) + 1);
183                 strcpy(curdev->name, name);
184                 if (description != NULL) {
185                         /*
186                          * We have a description for this interface.
187                          */
188                         curdev->description = malloc(strlen(description) + 1);
189                         strcpy(curdev->description, description);
190                 } else {
191                         /*
192                          * We don't.
193                          */
194                         curdev->description = NULL;
195                 }
196                 curdev->addresses = NULL;       /* list starts out as empty */
197                 curdev->flags = 0;
198                 if (ISLOOPBACK(name, flags))
199                         curdev->flags |= PCAP_IF_LOOPBACK;
200
201                 /*
202                  * Add it to the list, in the appropriate location.
203                  * First, get the instance number of this interface.
204                  */
205                 this_instance = get_instance(name);
206
207                 /*
208                  * Now look for the last interface with an instance number
209                  * less than or equal to the new interface's instance
210                  * number - except that non-loopback interfaces are
211                  * arbitrarily treated as having interface numbers less
212                  * than those of loopback interfaces, so the loopback
213                  * interfaces are put at the end of the list.
214                  *
215                  * We start with "prevdev" being NULL, meaning we're before
216                  * the first element in the list.
217                  */
218                 prevdev = NULL;
219                 for (;;) {
220                         /*
221                          * Get the interface after this one.
222                          */
223                         if (prevdev == NULL) {
224                                 /*
225                                  * The next element is the first element.
226                                  */
227                                 nextdev = *alldevs;
228                         } else
229                                 nextdev = prevdev->next;
230
231                         /*
232                          * Are we at the end of the list?
233                          */
234                         if (nextdev == NULL) {
235                                 /*
236                                  * Yes - we have to put the new entry
237                                  * after "prevdev".
238                                  */
239                                 break;
240                         }
241
242                         /*
243                          * Is the new interface a non-loopback interface
244                          * and the next interface a loopback interface?
245                          */
246                         if (!(curdev->flags & PCAP_IF_LOOPBACK) &&
247                             (nextdev->flags & PCAP_IF_LOOPBACK)) {
248                                 /*
249                                  * Yes, we should put the new entry
250                                  * before "nextdev", i.e. after "prevdev".
251                                  */
252                                 break;
253                         }
254
255                         /*
256                          * Is the new interface's instance number less
257                          * than the next interface's instance number,
258                          * and is it the case that the new interface is a
259                          * non-loopback interface or the next interface is
260                          * a loopback interface?
261                          *
262                          * (The goal of both loopback tests is to make
263                          * sure that we never put a loopback interface
264                          * before any non-loopback interface and that we
265                          * always put a non-loopback interface before all
266                          * loopback interfaces.)
267                          */
268                         if (this_instance < get_instance(nextdev->name) &&
269                             (!(curdev->flags & PCAP_IF_LOOPBACK) ||
270                                (nextdev->flags & PCAP_IF_LOOPBACK))) {
271                                 /*
272                                  * Yes - we should put the new entry
273                                  * before "nextdev", i.e. after "prevdev".
274                                  */
275                                 break;
276                         }
277
278                         prevdev = nextdev;
279                 }
280
281                 /*
282                  * Insert before "nextdev".
283                  */
284                 curdev->next = nextdev;
285
286                 /*
287                  * Insert after "prevdev" - unless "prevdev" is null,
288                  * in which case this is the first interface.
289                  */
290                 if (prevdev == NULL) {
291                         /*
292                          * This is the first interface.  Pass back a
293                          * pointer to it, and put "curdev" before
294                          * "nextdev".
295                          */
296                         *alldevs = curdev;
297                 } else
298                         prevdev->next = curdev;
299         }
300
301         *curdev_ret = curdev;
302         return (0);
303 }
304
305 int
306 add_addr_to_iflist(pcap_if_t **alldevs, const char *name, u_int flags,
307     struct sockaddr *addr, size_t addr_size,
308     struct sockaddr *netmask, size_t netmask_size,
309     struct sockaddr *broadaddr, size_t broadaddr_size,
310     struct sockaddr *dstaddr, size_t dstaddr_size,
311     char *errbuf)
312 {
313         pcap_if_t *curdev;
314         pcap_addr_t *curaddr, *prevaddr, *nextaddr;
315
316         if (add_or_find_if(&curdev, alldevs, name, flags, NULL, errbuf) == -1) {
317                 /*
318                  * Error - give up.
319                  */
320                 return (-1);
321         }
322         if (curdev == NULL) {
323                 /*
324                  * Device wasn't added because it can't be opened.
325                  * Not a fatal error.
326                  */
327                 return (0);
328         }
329
330         /*
331          * "curdev" is an entry for this interface; add an entry for this
332          * address to its list of addresses.
333          *
334          * Allocate the new entry and fill it in.
335          */
336         curaddr = malloc(sizeof(pcap_addr_t));
337         if (curaddr == NULL) {
338                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
339                     "malloc: %s", pcap_strerror(errno));
340                 return (-1);
341         }
342
343         curaddr->next = NULL;
344         if (addr != NULL) {
345                 curaddr->addr = dup_sockaddr(addr, addr_size);
346                 if (curaddr->addr == NULL) {
347                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
348                             "malloc: %s", pcap_strerror(errno));
349                         free(curaddr);
350                         return (-1);
351                 }
352         } else
353                 curaddr->addr = NULL;
354
355         if (netmask != NULL) {
356                 curaddr->netmask = dup_sockaddr(netmask, netmask_size);
357                 if (curaddr->netmask == NULL) {
358                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
359                             "malloc: %s", pcap_strerror(errno));
360                         free(curaddr);
361                         return (-1);
362                 }
363         } else
364                 curaddr->netmask = NULL;
365
366         if (broadaddr != NULL) {
367                 curaddr->broadaddr = dup_sockaddr(broadaddr, broadaddr_size);
368                 if (curaddr->broadaddr == NULL) {
369                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
370                             "malloc: %s", pcap_strerror(errno));
371                         free(curaddr);
372                         return (-1);
373                 }
374         } else
375                 curaddr->broadaddr = NULL;
376
377         if (dstaddr != NULL) {
378                 curaddr->dstaddr = dup_sockaddr(dstaddr, dstaddr_size);
379                 if (curaddr->dstaddr == NULL) {
380                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
381                             "malloc: %s", pcap_strerror(errno));
382                         free(curaddr);
383                         return (-1);
384                 }
385         } else
386                 curaddr->dstaddr = NULL;
387
388         /*
389          * Find the end of the list of addresses.
390          */
391         for (prevaddr = curdev->addresses; prevaddr != NULL; prevaddr = nextaddr) {
392                 nextaddr = prevaddr->next;
393                 if (nextaddr == NULL) {
394                         /*
395                          * This is the end of the list.
396                          */
397                         break;
398                 }
399         }
400
401         if (prevaddr == NULL) {
402                 /*
403                  * The list was empty; this is the first member.
404                  */
405                 curdev->addresses = curaddr;
406         } else {
407                 /*
408                  * "prevaddr" is the last member of the list; append
409                  * this member to it.
410                  */
411                 prevaddr->next = curaddr;
412         }
413
414         return (0);
415 }
416
417 int
418 pcap_add_if(pcap_if_t **devlist, const char *name, u_int flags,
419     const char *description, char *errbuf)
420 {
421         pcap_if_t *curdev;
422
423         return (add_or_find_if(&curdev, devlist, name, flags, description,
424             errbuf));
425 }
426
427
428 /*
429  * Free a list of interfaces.
430  */
431 void
432 pcap_freealldevs(pcap_if_t *alldevs)
433 {
434         pcap_if_t *curdev, *nextdev;
435         pcap_addr_t *curaddr, *nextaddr;
436
437         for (curdev = alldevs; curdev != NULL; curdev = nextdev) {
438                 nextdev = curdev->next;
439
440                 /*
441                  * Free all addresses.
442                  */
443                 for (curaddr = curdev->addresses; curaddr != NULL; curaddr = nextaddr) {
444                         nextaddr = curaddr->next;
445                         if (curaddr->addr)
446                                 free(curaddr->addr);
447                         if (curaddr->netmask)
448                                 free(curaddr->netmask);
449                         if (curaddr->broadaddr)
450                                 free(curaddr->broadaddr);
451                         if (curaddr->dstaddr)
452                                 free(curaddr->dstaddr);
453                         free(curaddr);
454                 }
455
456                 /*
457                  * Free the name string.
458                  */
459                 free(curdev->name);
460
461                 /*
462                  * Free the description string, if any.
463                  */
464                 if (curdev->description != NULL)
465                         free(curdev->description);
466
467                 /*
468                  * Free the interface.
469                  */
470                 free(curdev);
471         }
472 }
473
474 #if !defined(WIN32) && !defined(MSDOS)
475
476 /*
477  * Return the name of a network interface attached to the system, or NULL
478  * if none can be found.  The interface must be configured up; the
479  * lowest unit number is preferred; loopback is ignored.
480  */
481 char *
482 pcap_lookupdev(errbuf)
483         register char *errbuf;
484 {
485         pcap_if_t *alldevs;
486 /* for old BSD systems, including bsdi3 */
487 #ifndef IF_NAMESIZE
488 #define IF_NAMESIZE IFNAMSIZ
489 #endif
490         static char device[IF_NAMESIZE + 1];
491         char *ret;
492
493         if (pcap_findalldevs(&alldevs, errbuf) == -1)
494                 return (NULL);
495
496         if (alldevs == NULL || (alldevs->flags & PCAP_IF_LOOPBACK)) {
497                 /*
498                  * There are no devices on the list, or the first device
499                  * on the list is a loopback device, which means there
500                  * are no non-loopback devices on the list.  This means
501                  * we can't return any device.
502                  *
503                  * XXX - why not return a loopback device?  If we can't
504                  * capture on it, it won't be on the list, and if it's
505                  * on the list, there aren't any non-loopback devices,
506                  * so why not just supply it as the default device?
507                  */
508                 (void)strlcpy(errbuf, "no suitable device found",
509                     PCAP_ERRBUF_SIZE);
510                 ret = NULL;
511         } else {
512                 /*
513                  * Return the name of the first device on the list.
514                  */
515                 (void)strlcpy(device, alldevs->name, sizeof(device));
516                 ret = device;
517         }
518
519         pcap_freealldevs(alldevs);
520         return (ret);
521 }
522
523 int
524 pcap_lookupnet(device, netp, maskp, errbuf)
525         register const char *device;
526         register bpf_u_int32 *netp, *maskp;
527         register char *errbuf;
528 {
529         register int fd;
530         register struct sockaddr_in *sin;
531         struct ifreq ifr;
532
533         /*
534          * The pseudo-device "any" listens on all interfaces and therefore
535          * has the network address and -mask "0.0.0.0" therefore catching
536          * all traffic. Using NULL for the interface is the same as "any".
537          */
538         if (!device || strcmp(device, "any") == 0
539 #ifdef HAVE_DAG_API
540             || strstr(device, "dag") != NULL
541 #endif
542 #ifdef HAVE_SEPTEL_API
543             || strstr(device, "septel") != NULL
544 #endif
545             ) {
546                 *netp = *maskp = 0;
547                 return 0;
548         }
549
550         fd = socket(AF_INET, SOCK_DGRAM, 0);
551         if (fd < 0) {
552                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "socket: %s",
553                     pcap_strerror(errno));
554                 return (-1);
555         }
556         memset(&ifr, 0, sizeof(ifr));
557 #ifdef linux
558         /* XXX Work around Linux kernel bug */
559         ifr.ifr_addr.sa_family = AF_INET;
560 #endif
561         (void)strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
562         if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0) {
563                 if (errno == EADDRNOTAVAIL) {
564                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
565                             "%s: no IPv4 address assigned", device);
566                 } else {
567                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
568                             "SIOCGIFADDR: %s: %s",
569                             device, pcap_strerror(errno));
570                 }
571                 (void)close(fd);
572                 return (-1);
573         }
574         sin = (struct sockaddr_in *)&ifr.ifr_addr;
575         *netp = sin->sin_addr.s_addr;
576         if (ioctl(fd, SIOCGIFNETMASK, (char *)&ifr) < 0) {
577                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
578                     "SIOCGIFNETMASK: %s: %s", device, pcap_strerror(errno));
579                 (void)close(fd);
580                 return (-1);
581         }
582         (void)close(fd);
583         *maskp = sin->sin_addr.s_addr;
584         if (*maskp == 0) {
585                 if (IN_CLASSA(*netp))
586                         *maskp = IN_CLASSA_NET;
587                 else if (IN_CLASSB(*netp))
588                         *maskp = IN_CLASSB_NET;
589                 else if (IN_CLASSC(*netp))
590                         *maskp = IN_CLASSC_NET;
591                 else {
592                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
593                             "inet class for 0x%x unknown", *netp);
594                         return (-1);
595                 }
596         }
597         *netp &= *maskp;
598         return (0);
599 }
600
601 #elif defined(WIN32)
602
603 /*
604  * Return the name of a network interface attached to the system, or NULL
605  * if none can be found.  The interface must be configured up; the
606  * lowest unit number is preferred; loopback is ignored.
607  */
608 char *
609 pcap_lookupdev(errbuf)
610         register char *errbuf;
611 {
612         DWORD dwVersion;
613         DWORD dwWindowsMajorVersion;
614         dwVersion = GetVersion();       /* get the OS version */
615         dwWindowsMajorVersion = (DWORD)(LOBYTE(LOWORD(dwVersion)));
616         
617         if (dwVersion >= 0x80000000 && dwWindowsMajorVersion >= 4) {
618                 /*
619                  * Windows 95, 98, ME.
620                  */
621                 ULONG NameLength = 8192;
622                 static char AdaptersName[8192];
623                 
624                 if (PacketGetAdapterNames(AdaptersName,&NameLength) )
625                         return (AdaptersName);
626                 else
627                         return NULL;
628         } else {
629                 /*
630                  * Windows NT (NT 4.0, W2K, WXP). Convert the names to UNICODE for backward compatibility
631                  */
632                 ULONG NameLength = 8192;
633                 static WCHAR AdaptersName[8192];
634                 char *tAstr;
635                 WCHAR *tUstr;
636                 WCHAR *TAdaptersName = (WCHAR*)malloc(8192 * sizeof(WCHAR));
637                 int NAdapts = 0;
638
639                 if(TAdaptersName == NULL)
640                 {
641                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "memory allocation failure");
642                         return NULL;
643                 }
644
645                 if ( !PacketGetAdapterNames((PTSTR)TAdaptersName,&NameLength) )
646                 {
647                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
648                                 "PacketGetAdapterNames: %s",
649                                 pcap_win32strerror());
650                         free(TAdaptersName);
651                         return NULL;
652                 }
653
654
655                 tAstr = (char*)TAdaptersName;
656                 tUstr = (WCHAR*)AdaptersName;
657
658                 /*
659                  * Convert and copy the device names
660                  */
661                 while(sscanf(tAstr, "%S", tUstr) > 0)
662                 {
663                         tAstr += strlen(tAstr) + 1;
664                         tUstr += wcslen(tUstr) + 1;
665                         NAdapts ++;
666                 }
667
668                 tAstr++;
669                 *tUstr = 0;
670                 tUstr++;
671
672                 /*
673                  * Copy the descriptions
674                  */
675                 while(NAdapts--)
676                 {
677                         strcpy((char*)tUstr, tAstr);
678                         (char*)tUstr += strlen(tAstr) + 1;;
679                         tAstr += strlen(tAstr) + 1;
680                 }
681
682                 free(TAdaptersName);
683                 return (char *)(AdaptersName);
684         }       
685 }
686
687
688 int
689 pcap_lookupnet(device, netp, maskp, errbuf)
690         register const char *device;
691         register bpf_u_int32 *netp, *maskp;
692         register char *errbuf;
693 {
694         /* 
695          * We need only the first IPv4 address, so we must scan the array returned by PacketGetNetInfo()
696          * in order to skip non IPv4 (i.e. IPv6 addresses)
697          */
698         npf_if_addr if_addrs[MAX_NETWORK_ADDRESSES];
699         LONG if_addr_size = 1;
700         struct sockaddr_in *t_addr;
701         unsigned int i;
702
703         if (!PacketGetNetInfoEx((void *)device, if_addrs, &if_addr_size)) {
704                 *netp = *maskp = 0;
705                 return (0);
706         }
707
708         for(i=0; i<MAX_NETWORK_ADDRESSES; i++)
709         {
710                 if(if_addrs[i].IPAddress.ss_family == AF_INET)
711                 {
712                         t_addr = (struct sockaddr_in *) &(if_addrs[i].IPAddress);
713                         *netp = t_addr->sin_addr.S_un.S_addr;
714                         t_addr = (struct sockaddr_in *) &(if_addrs[i].SubnetMask);
715                         *maskp = t_addr->sin_addr.S_un.S_addr;
716
717                         *netp &= *maskp;
718                         return (0);
719                 }
720                                 
721         }
722
723         *netp = *maskp = 0;
724         return (0);
725 }
726
727 #endif /* !WIN32 && !MSDOS */