xref: /freebsd/contrib/libpcap/fad-glifc.c (revision 3a92d97ff0f22d21608e1c19b83104c4937523b6)
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/fad-glifc.c,v 1.7 2008-01-30 09:35:48 guy Exp $ (LBL)";
38 #endif
39 
40 #ifdef HAVE_CONFIG_H
41 #include "config.h"
42 #endif
43 
44 #include <sys/param.h>
45 #include <sys/file.h>
46 #include <sys/ioctl.h>
47 #include <sys/socket.h>
48 #ifdef HAVE_SYS_SOCKIO_H
49 #include <sys/sockio.h>
50 #endif
51 #include <sys/time.h>				/* concession to AIX */
52 
53 struct mbuf;		/* Squelch compiler warnings on some platforms for */
54 struct rtentry;		/* declarations in <net/if.h> */
55 #include <net/if.h>
56 #include <netinet/in.h>
57 
58 #include <ctype.h>
59 #include <errno.h>
60 #include <memory.h>
61 #include <stdio.h>
62 #include <stdlib.h>
63 #include <string.h>
64 #include <unistd.h>
65 
66 #include "pcap-int.h"
67 
68 #ifdef HAVE_OS_PROTO_H
69 #include "os-proto.h"
70 #endif
71 
72 /*
73  * Get a list of all interfaces that are up and that we can open.
74  * Returns -1 on error, 0 otherwise.
75  * The list, as returned through "alldevsp", may be null if no interfaces
76  * were up and could be opened.
77  *
78  * This is the implementation used on platforms that have SIOCGLIFCONF
79  * but don't have "getifaddrs()".  (Solaris 8 and later; we use
80  * SIOCGLIFCONF rather than SIOCGIFCONF in order to get IPv6 addresses.)
81  */
82 int
83 pcap_findalldevs_interfaces(pcap_if_t **alldevsp, char *errbuf)
84 {
85 	pcap_if_t *devlist = NULL;
86 	register int fd4, fd6, fd;
87 	register struct lifreq *ifrp, *ifend;
88 	struct lifnum ifn;
89 	struct lifconf ifc;
90 	char *buf = NULL;
91 	unsigned buf_size;
92 #ifdef HAVE_SOLARIS
93 	char *p, *q;
94 #endif
95 	struct lifreq ifrflags, ifrnetmask, ifrbroadaddr, ifrdstaddr;
96 	struct sockaddr *netmask, *broadaddr, *dstaddr;
97 	int ret = 0;
98 
99 	/*
100 	 * Create a socket from which to fetch the list of interfaces,
101 	 * and from which to fetch IPv4 information.
102 	 */
103 	fd4 = socket(AF_INET, SOCK_DGRAM, 0);
104 	if (fd4 < 0) {
105 		(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
106 		    "socket: %s", pcap_strerror(errno));
107 		return (-1);
108 	}
109 
110 	/*
111 	 * Create a socket from which to fetch IPv6 information.
112 	 */
113 	fd6 = socket(AF_INET6, SOCK_DGRAM, 0);
114 	if (fd6 < 0) {
115 		(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
116 		    "socket: %s", pcap_strerror(errno));
117 		(void)close(fd4);
118 		return (-1);
119 	}
120 
121 	/*
122 	 * How many entries will SIOCGLIFCONF return?
123 	 */
124 	ifn.lifn_family = AF_UNSPEC;
125 	ifn.lifn_flags = 0;
126 	ifn.lifn_count = 0;
127 	if (ioctl(fd4, SIOCGLIFNUM, (char *)&ifn) < 0) {
128 		(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
129 		    "SIOCGLIFNUM: %s", pcap_strerror(errno));
130 		(void)close(fd6);
131 		(void)close(fd4);
132 		return (-1);
133 	}
134 
135 	/*
136 	 * Allocate a buffer for those entries.
137 	 */
138 	buf_size = ifn.lifn_count * sizeof (struct lifreq);
139 	buf = malloc(buf_size);
140 	if (buf == NULL) {
141 		(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
142 		    "malloc: %s", pcap_strerror(errno));
143 		(void)close(fd6);
144 		(void)close(fd4);
145 		return (-1);
146 	}
147 
148 	/*
149 	 * Get the entries.
150 	 */
151 	ifc.lifc_len = buf_size;
152 	ifc.lifc_buf = buf;
153 	ifc.lifc_family = AF_UNSPEC;
154 	ifc.lifc_flags = 0;
155 	memset(buf, 0, buf_size);
156 	if (ioctl(fd4, SIOCGLIFCONF, (char *)&ifc) < 0) {
157 		(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
158 		    "SIOCGLIFCONF: %s", pcap_strerror(errno));
159 		(void)close(fd6);
160 		(void)close(fd4);
161 		free(buf);
162 		return (-1);
163 	}
164 
165 	/*
166 	 * Loop over the entries.
167 	 */
168 	ifrp = (struct lifreq *)buf;
169 	ifend = (struct lifreq *)(buf + ifc.lifc_len);
170 
171 	for (; ifrp < ifend; ifrp++) {
172 		/*
173 		 * IPv6 or not?
174 		 */
175 		if (((struct sockaddr *)&ifrp->lifr_addr)->sa_family == AF_INET6)
176 			fd = fd6;
177 		else
178 			fd = fd4;
179 
180 		/*
181 		 * Skip entries that begin with "dummy".
182 		 * XXX - what are these?  Is this Linux-specific?
183 		 * Are there platforms on which we shouldn't do this?
184 		 */
185 		if (strncmp(ifrp->lifr_name, "dummy", 5) == 0)
186 			continue;
187 
188 #ifdef HAVE_SOLARIS
189 		/*
190 		 * Skip entries that have a ":" followed by a number
191 		 * at the end - those are Solaris virtual interfaces
192 		 * on which you can't capture.
193 		 */
194 		p = strchr(ifrp->lifr_name, ':');
195 		if (p != NULL) {
196 			/*
197 			 * We have a ":"; is it followed by a number?
198 			 */
199 			while (isdigit((unsigned char)*p))
200 				p++;
201 			if (*p == '\0') {
202 				/*
203 				 * All digits after the ":" until the end.
204 				 */
205 				continue;
206 			}
207 		}
208 #endif
209 
210 		/*
211 		 * Get the flags for this interface, and skip it if it's
212 		 * not up.
213 		 */
214 		strncpy(ifrflags.lifr_name, ifrp->lifr_name,
215 		    sizeof(ifrflags.lifr_name));
216 		if (ioctl(fd, SIOCGLIFFLAGS, (char *)&ifrflags) < 0) {
217 			if (errno == ENXIO)
218 				continue;
219 			(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
220 			    "SIOCGLIFFLAGS: %.*s: %s",
221 			    (int)sizeof(ifrflags.lifr_name),
222 			    ifrflags.lifr_name,
223 			    pcap_strerror(errno));
224 			ret = -1;
225 			break;
226 		}
227 		if (!(ifrflags.lifr_flags & IFF_UP))
228 			continue;
229 
230 		/*
231 		 * Get the netmask for this address on this interface.
232 		 */
233 		strncpy(ifrnetmask.lifr_name, ifrp->lifr_name,
234 		    sizeof(ifrnetmask.lifr_name));
235 		memcpy(&ifrnetmask.lifr_addr, &ifrp->lifr_addr,
236 		    sizeof(ifrnetmask.lifr_addr));
237 		if (ioctl(fd, SIOCGLIFNETMASK, (char *)&ifrnetmask) < 0) {
238 			if (errno == EADDRNOTAVAIL) {
239 				/*
240 				 * Not available.
241 				 */
242 				netmask = NULL;
243 			} else {
244 				(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
245 				    "SIOCGLIFNETMASK: %.*s: %s",
246 				    (int)sizeof(ifrnetmask.lifr_name),
247 				    ifrnetmask.lifr_name,
248 				    pcap_strerror(errno));
249 				ret = -1;
250 				break;
251 			}
252 		} else
253 			netmask = (struct sockaddr *)&ifrnetmask.lifr_addr;
254 
255 		/*
256 		 * Get the broadcast address for this address on this
257 		 * interface (if any).
258 		 */
259 		if (ifrflags.lifr_flags & IFF_BROADCAST) {
260 			strncpy(ifrbroadaddr.lifr_name, ifrp->lifr_name,
261 			    sizeof(ifrbroadaddr.lifr_name));
262 			memcpy(&ifrbroadaddr.lifr_addr, &ifrp->lifr_addr,
263 			    sizeof(ifrbroadaddr.lifr_addr));
264 			if (ioctl(fd, SIOCGLIFBRDADDR,
265 			    (char *)&ifrbroadaddr) < 0) {
266 				if (errno == EADDRNOTAVAIL) {
267 					/*
268 					 * Not available.
269 					 */
270 					broadaddr = NULL;
271 				} else {
272 					(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
273 					    "SIOCGLIFBRDADDR: %.*s: %s",
274 					    (int)sizeof(ifrbroadaddr.lifr_name),
275 					    ifrbroadaddr.lifr_name,
276 					    pcap_strerror(errno));
277 					ret = -1;
278 					break;
279 				}
280 			} else
281 				broadaddr = (struct sockaddr *)&ifrbroadaddr.lifr_broadaddr;
282 		} else {
283 			/*
284 			 * Not a broadcast interface, so no broadcast
285 			 * address.
286 			 */
287 			broadaddr = NULL;
288 		}
289 
290 		/*
291 		 * Get the destination address for this address on this
292 		 * interface (if any).
293 		 */
294 		if (ifrflags.lifr_flags & IFF_POINTOPOINT) {
295 			strncpy(ifrdstaddr.lifr_name, ifrp->lifr_name,
296 			    sizeof(ifrdstaddr.lifr_name));
297 			memcpy(&ifrdstaddr.lifr_addr, &ifrp->lifr_addr,
298 			    sizeof(ifrdstaddr.lifr_addr));
299 			if (ioctl(fd, SIOCGLIFDSTADDR,
300 			    (char *)&ifrdstaddr) < 0) {
301 				if (errno == EADDRNOTAVAIL) {
302 					/*
303 					 * Not available.
304 					 */
305 					dstaddr = NULL;
306 				} else {
307 					(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
308 					    "SIOCGLIFDSTADDR: %.*s: %s",
309 					    (int)sizeof(ifrdstaddr.lifr_name),
310 					    ifrdstaddr.lifr_name,
311 					    pcap_strerror(errno));
312 					ret = -1;
313 					break;
314 				}
315 			} else
316 				dstaddr = (struct sockaddr *)&ifrdstaddr.lifr_dstaddr;
317 		} else
318 			dstaddr = NULL;
319 
320 #ifdef HAVE_SOLARIS
321 		/*
322 		 * If this entry has a colon followed by a number at
323 		 * the end, it's a logical interface.  Those are just
324 		 * the way you assign multiple IP addresses to a real
325 		 * interface, so an entry for a logical interface should
326 		 * be treated like the entry for the real interface;
327 		 * we do that by stripping off the ":" and the number.
328 		 */
329 		p = strchr(ifrp->lifr_name, ':');
330 		if (p != NULL) {
331 			/*
332 			 * We have a ":"; is it followed by a number?
333 			 */
334 			q = p + 1;
335 			while (isdigit((unsigned char)*q))
336 				q++;
337 			if (*q == '\0') {
338 				/*
339 				 * All digits after the ":" until the end.
340 				 * Strip off the ":" and everything after
341 				 * it.
342 				 */
343 				*p = '\0';
344 			}
345 		}
346 #endif
347 
348 		/*
349 		 * Add information for this address to the list.
350 		 */
351 		if (add_addr_to_iflist(&devlist, ifrp->lifr_name,
352 		    ifrflags.lifr_flags, (struct sockaddr *)&ifrp->lifr_addr,
353 		    sizeof (struct sockaddr_storage),
354 		    netmask, sizeof (struct sockaddr_storage),
355 		    broadaddr, sizeof (struct sockaddr_storage),
356 		    dstaddr, sizeof (struct sockaddr_storage), errbuf) < 0) {
357 			ret = -1;
358 			break;
359 		}
360 	}
361 	free(buf);
362 	(void)close(fd6);
363 	(void)close(fd4);
364 
365 	if (ret == -1) {
366 		/*
367 		 * We had an error; free the list we've been constructing.
368 		 */
369 		if (devlist != NULL) {
370 			pcap_freealldevs(devlist);
371 			devlist = NULL;
372 		}
373 	}
374 
375 	*alldevsp = devlist;
376 	return (ret);
377 }
378