xref: /netbsd-src/external/bsd/libpcap/dist/fad-glifc.c (revision b7b7574d3bf8eeb51a1fa3977b59142ec6434a55)
1 /*	$NetBSD: fad-glifc.c,v 1.1.1.4 2013/12/31 16:57:18 christos Exp $	*/
2 
3 /* -*- Mode: c; tab-width: 8; indent-tabs-mode: 1; c-basic-offset: 8; -*- */
4 /*
5  * Copyright (c) 1994, 1995, 1996, 1997, 1998
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the Computer Systems
19  *	Engineering Group at Lawrence Berkeley Laboratory.
20  * 4. Neither the name of the University nor of the Laboratory may be used
21  *    to endorse or promote products derived from this software without
22  *    specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #ifndef lint
38 static const char rcsid[] _U_ =
39     "@(#) Header: /tcpdump/master/libpcap/fad-glifc.c,v 1.7 2008-01-30 09:35:48 guy Exp  (LBL)";
40 #endif
41 
42 #ifdef HAVE_CONFIG_H
43 #include "config.h"
44 #endif
45 
46 #include <sys/param.h>
47 #include <sys/file.h>
48 #include <sys/ioctl.h>
49 #include <sys/socket.h>
50 #ifdef HAVE_SYS_SOCKIO_H
51 #include <sys/sockio.h>
52 #endif
53 #include <sys/time.h>				/* concession to AIX */
54 
55 struct mbuf;		/* Squelch compiler warnings on some platforms for */
56 struct rtentry;		/* declarations in <net/if.h> */
57 #include <net/if.h>
58 #include <netinet/in.h>
59 
60 #include <ctype.h>
61 #include <errno.h>
62 #include <memory.h>
63 #include <stdio.h>
64 #include <stdlib.h>
65 #include <string.h>
66 #include <unistd.h>
67 
68 #include "pcap-int.h"
69 
70 #ifdef HAVE_OS_PROTO_H
71 #include "os-proto.h"
72 #endif
73 
74 /*
75  * Get a list of all interfaces that are up and that we can open.
76  * Returns -1 on error, 0 otherwise.
77  * The list, as returned through "alldevsp", may be null if no interfaces
78  * were up and could be opened.
79  *
80  * This is the implementation used on platforms that have SIOCGLIFCONF
81  * but don't have "getifaddrs()".  (Solaris 8 and later; we use
82  * SIOCGLIFCONF rather than SIOCGIFCONF in order to get IPv6 addresses.)
83  */
84 int
85 pcap_findalldevs_interfaces(pcap_if_t **alldevsp, char *errbuf)
86 {
87 	pcap_if_t *devlist = NULL;
88 	register int fd4, fd6, fd;
89 	register struct lifreq *ifrp, *ifend;
90 	struct lifnum ifn;
91 	struct lifconf ifc;
92 	char *buf = NULL;
93 	unsigned buf_size;
94 #ifdef HAVE_SOLARIS
95 	char *p, *q;
96 #endif
97 	struct lifreq ifrflags, ifrnetmask, ifrbroadaddr, ifrdstaddr;
98 	struct sockaddr *netmask, *broadaddr, *dstaddr;
99 	int ret = 0;
100 
101 	/*
102 	 * Create a socket from which to fetch the list of interfaces,
103 	 * and from which to fetch IPv4 information.
104 	 */
105 	fd4 = socket(AF_INET, SOCK_DGRAM, 0);
106 	if (fd4 < 0) {
107 		(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
108 		    "socket: %s", pcap_strerror(errno));
109 		return (-1);
110 	}
111 
112 	/*
113 	 * Create a socket from which to fetch IPv6 information.
114 	 */
115 	fd6 = socket(AF_INET6, SOCK_DGRAM, 0);
116 	if (fd6 < 0) {
117 		(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
118 		    "socket: %s", pcap_strerror(errno));
119 		(void)close(fd4);
120 		return (-1);
121 	}
122 
123 	/*
124 	 * How many entries will SIOCGLIFCONF return?
125 	 */
126 	ifn.lifn_family = AF_UNSPEC;
127 	ifn.lifn_flags = 0;
128 	ifn.lifn_count = 0;
129 	if (ioctl(fd4, SIOCGLIFNUM, (char *)&ifn) < 0) {
130 		(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
131 		    "SIOCGLIFNUM: %s", pcap_strerror(errno));
132 		(void)close(fd6);
133 		(void)close(fd4);
134 		return (-1);
135 	}
136 
137 	/*
138 	 * Allocate a buffer for those entries.
139 	 */
140 	buf_size = ifn.lifn_count * sizeof (struct lifreq);
141 	buf = malloc(buf_size);
142 	if (buf == NULL) {
143 		(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
144 		    "malloc: %s", pcap_strerror(errno));
145 		(void)close(fd6);
146 		(void)close(fd4);
147 		return (-1);
148 	}
149 
150 	/*
151 	 * Get the entries.
152 	 */
153 	ifc.lifc_len = buf_size;
154 	ifc.lifc_buf = buf;
155 	ifc.lifc_family = AF_UNSPEC;
156 	ifc.lifc_flags = 0;
157 	memset(buf, 0, buf_size);
158 	if (ioctl(fd4, SIOCGLIFCONF, (char *)&ifc) < 0) {
159 		(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
160 		    "SIOCGLIFCONF: %s", pcap_strerror(errno));
161 		(void)close(fd6);
162 		(void)close(fd4);
163 		free(buf);
164 		return (-1);
165 	}
166 
167 	/*
168 	 * Loop over the entries.
169 	 */
170 	ifrp = (struct lifreq *)buf;
171 	ifend = (struct lifreq *)(buf + ifc.lifc_len);
172 
173 	for (; ifrp < ifend; ifrp++) {
174 		/*
175 		 * IPv6 or not?
176 		 */
177 		if (((struct sockaddr *)&ifrp->lifr_addr)->sa_family == AF_INET6)
178 			fd = fd6;
179 		else
180 			fd = fd4;
181 
182 		/*
183 		 * Skip entries that begin with "dummy".
184 		 * XXX - what are these?  Is this Linux-specific?
185 		 * Are there platforms on which we shouldn't do this?
186 		 */
187 		if (strncmp(ifrp->lifr_name, "dummy", 5) == 0)
188 			continue;
189 
190 #ifdef HAVE_SOLARIS
191 		/*
192 		 * Skip entries that have a ":" followed by a number
193 		 * at the end - those are Solaris virtual interfaces
194 		 * on which you can't capture.
195 		 */
196 		p = strchr(ifrp->lifr_name, ':');
197 		if (p != NULL) {
198 			/*
199 			 * We have a ":"; is it followed by a number?
200 			 */
201 			while (isdigit((unsigned char)*p))
202 				p++;
203 			if (*p == '\0') {
204 				/*
205 				 * All digits after the ":" until the end.
206 				 */
207 				continue;
208 			}
209 		}
210 #endif
211 
212 		/*
213 		 * Get the flags for this interface, and skip it if it's
214 		 * not up.
215 		 */
216 		strncpy(ifrflags.lifr_name, ifrp->lifr_name,
217 		    sizeof(ifrflags.lifr_name));
218 		if (ioctl(fd, SIOCGLIFFLAGS, (char *)&ifrflags) < 0) {
219 			if (errno == ENXIO)
220 				continue;
221 			(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
222 			    "SIOCGLIFFLAGS: %.*s: %s",
223 			    (int)sizeof(ifrflags.lifr_name),
224 			    ifrflags.lifr_name,
225 			    pcap_strerror(errno));
226 			ret = -1;
227 			break;
228 		}
229 		if (!(ifrflags.lifr_flags & IFF_UP))
230 			continue;
231 
232 		/*
233 		 * Get the netmask for this address on this interface.
234 		 */
235 		strncpy(ifrnetmask.lifr_name, ifrp->lifr_name,
236 		    sizeof(ifrnetmask.lifr_name));
237 		memcpy(&ifrnetmask.lifr_addr, &ifrp->lifr_addr,
238 		    sizeof(ifrnetmask.lifr_addr));
239 		if (ioctl(fd, SIOCGLIFNETMASK, (char *)&ifrnetmask) < 0) {
240 			if (errno == EADDRNOTAVAIL) {
241 				/*
242 				 * Not available.
243 				 */
244 				netmask = NULL;
245 			} else {
246 				(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
247 				    "SIOCGLIFNETMASK: %.*s: %s",
248 				    (int)sizeof(ifrnetmask.lifr_name),
249 				    ifrnetmask.lifr_name,
250 				    pcap_strerror(errno));
251 				ret = -1;
252 				break;
253 			}
254 		} else
255 			netmask = (struct sockaddr *)&ifrnetmask.lifr_addr;
256 
257 		/*
258 		 * Get the broadcast address for this address on this
259 		 * interface (if any).
260 		 */
261 		if (ifrflags.lifr_flags & IFF_BROADCAST) {
262 			strncpy(ifrbroadaddr.lifr_name, ifrp->lifr_name,
263 			    sizeof(ifrbroadaddr.lifr_name));
264 			memcpy(&ifrbroadaddr.lifr_addr, &ifrp->lifr_addr,
265 			    sizeof(ifrbroadaddr.lifr_addr));
266 			if (ioctl(fd, SIOCGLIFBRDADDR,
267 			    (char *)&ifrbroadaddr) < 0) {
268 				if (errno == EADDRNOTAVAIL) {
269 					/*
270 					 * Not available.
271 					 */
272 					broadaddr = NULL;
273 				} else {
274 					(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
275 					    "SIOCGLIFBRDADDR: %.*s: %s",
276 					    (int)sizeof(ifrbroadaddr.lifr_name),
277 					    ifrbroadaddr.lifr_name,
278 					    pcap_strerror(errno));
279 					ret = -1;
280 					break;
281 				}
282 			} else
283 				broadaddr = (struct sockaddr *)&ifrbroadaddr.lifr_broadaddr;
284 		} else {
285 			/*
286 			 * Not a broadcast interface, so no broadcast
287 			 * address.
288 			 */
289 			broadaddr = NULL;
290 		}
291 
292 		/*
293 		 * Get the destination address for this address on this
294 		 * interface (if any).
295 		 */
296 		if (ifrflags.lifr_flags & IFF_POINTOPOINT) {
297 			strncpy(ifrdstaddr.lifr_name, ifrp->lifr_name,
298 			    sizeof(ifrdstaddr.lifr_name));
299 			memcpy(&ifrdstaddr.lifr_addr, &ifrp->lifr_addr,
300 			    sizeof(ifrdstaddr.lifr_addr));
301 			if (ioctl(fd, SIOCGLIFDSTADDR,
302 			    (char *)&ifrdstaddr) < 0) {
303 				if (errno == EADDRNOTAVAIL) {
304 					/*
305 					 * Not available.
306 					 */
307 					dstaddr = NULL;
308 				} else {
309 					(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
310 					    "SIOCGLIFDSTADDR: %.*s: %s",
311 					    (int)sizeof(ifrdstaddr.lifr_name),
312 					    ifrdstaddr.lifr_name,
313 					    pcap_strerror(errno));
314 					ret = -1;
315 					break;
316 				}
317 			} else
318 				dstaddr = (struct sockaddr *)&ifrdstaddr.lifr_dstaddr;
319 		} else
320 			dstaddr = NULL;
321 
322 #ifdef HAVE_SOLARIS
323 		/*
324 		 * If this entry has a colon followed by a number at
325 		 * the end, it's a logical interface.  Those are just
326 		 * the way you assign multiple IP addresses to a real
327 		 * interface, so an entry for a logical interface should
328 		 * be treated like the entry for the real interface;
329 		 * we do that by stripping off the ":" and the number.
330 		 */
331 		p = strchr(ifrp->lifr_name, ':');
332 		if (p != NULL) {
333 			/*
334 			 * We have a ":"; is it followed by a number?
335 			 */
336 			q = p + 1;
337 			while (isdigit((unsigned char)*q))
338 				q++;
339 			if (*q == '\0') {
340 				/*
341 				 * All digits after the ":" until the end.
342 				 * Strip off the ":" and everything after
343 				 * it.
344 				 */
345 				*p = '\0';
346 			}
347 		}
348 #endif
349 
350 		/*
351 		 * Add information for this address to the list.
352 		 */
353 		if (add_addr_to_iflist(&devlist, ifrp->lifr_name,
354 		    ifrflags.lifr_flags, (struct sockaddr *)&ifrp->lifr_addr,
355 		    sizeof (struct sockaddr_storage),
356 		    netmask, sizeof (struct sockaddr_storage),
357 		    broadaddr, sizeof (struct sockaddr_storage),
358 		    dstaddr, sizeof (struct sockaddr_storage), errbuf) < 0) {
359 			ret = -1;
360 			break;
361 		}
362 	}
363 	free(buf);
364 	(void)close(fd6);
365 	(void)close(fd4);
366 
367 	if (ret == -1) {
368 		/*
369 		 * We had an error; free the list we've been constructing.
370 		 */
371 		if (devlist != NULL) {
372 			pcap_freealldevs(devlist);
373 			devlist = NULL;
374 		}
375 	}
376 
377 	*alldevsp = devlist;
378 	return (ret);
379 }
380