xref: /freebsd/contrib/libpcap/fad-glifc.c (revision 193d9e768ba63fcfb187cfd17f461f7d41345048)
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 #ifdef HAVE_CONFIG_H
36 #include "config.h"
37 #endif
38 
39 #include <sys/param.h>
40 #include <sys/file.h>
41 #include <sys/ioctl.h>
42 #include <sys/socket.h>
43 #ifdef HAVE_SYS_SOCKIO_H
44 #include <sys/sockio.h>
45 #endif
46 #include <sys/time.h>				/* concession to AIX */
47 
48 struct mbuf;		/* Squelch compiler warnings on some platforms for */
49 struct rtentry;		/* declarations in <net/if.h> */
50 #include <net/if.h>
51 #include <netinet/in.h>
52 
53 #include <ctype.h>
54 #include <errno.h>
55 #include <memory.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <string.h>
59 #include <unistd.h>
60 
61 #include "pcap-int.h"
62 
63 #ifdef HAVE_OS_PROTO_H
64 #include "os-proto.h"
65 #endif
66 
67 /*
68  * Get a list of all interfaces that are up and that we can open.
69  * Returns -1 on error, 0 otherwise.
70  * The list, as returned through "alldevsp", may be null if no interfaces
71  * were up and could be opened.
72  *
73  * This is the implementation used on platforms that have SIOCGLIFCONF
74  * but don't have "getifaddrs()".  (Solaris 8 and later; we use
75  * SIOCGLIFCONF rather than SIOCGIFCONF in order to get IPv6 addresses.)
76  */
77 int
78 pcap_findalldevs_interfaces(pcap_if_t **alldevsp, char *errbuf,
79     int (*check_usable)(const char *))
80 {
81 	pcap_if_t *devlist = NULL;
82 	register int fd4, fd6, fd;
83 	register struct lifreq *ifrp, *ifend;
84 	struct lifnum ifn;
85 	struct lifconf ifc;
86 	char *buf = NULL;
87 	unsigned buf_size;
88 #ifdef HAVE_SOLARIS
89 	char *p, *q;
90 #endif
91 	struct lifreq ifrflags, ifrnetmask, ifrbroadaddr, ifrdstaddr;
92 	struct sockaddr *netmask, *broadaddr, *dstaddr;
93 	int ret = 0;
94 
95 	/*
96 	 * Create a socket from which to fetch the list of interfaces,
97 	 * and from which to fetch IPv4 information.
98 	 */
99 	fd4 = socket(AF_INET, SOCK_DGRAM, 0);
100 	if (fd4 < 0) {
101 		(void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
102 		    "socket: %s", pcap_strerror(errno));
103 		return (-1);
104 	}
105 
106 	/*
107 	 * Create a socket from which to fetch IPv6 information.
108 	 */
109 	fd6 = socket(AF_INET6, SOCK_DGRAM, 0);
110 	if (fd6 < 0) {
111 		(void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
112 		    "socket: %s", pcap_strerror(errno));
113 		(void)close(fd4);
114 		return (-1);
115 	}
116 
117 	/*
118 	 * How many entries will SIOCGLIFCONF return?
119 	 */
120 	ifn.lifn_family = AF_UNSPEC;
121 	ifn.lifn_flags = 0;
122 	ifn.lifn_count = 0;
123 	if (ioctl(fd4, SIOCGLIFNUM, (char *)&ifn) < 0) {
124 		(void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
125 		    "SIOCGLIFNUM: %s", pcap_strerror(errno));
126 		(void)close(fd6);
127 		(void)close(fd4);
128 		return (-1);
129 	}
130 
131 	/*
132 	 * Allocate a buffer for those entries.
133 	 */
134 	buf_size = ifn.lifn_count * sizeof (struct lifreq);
135 	buf = malloc(buf_size);
136 	if (buf == NULL) {
137 		(void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
138 		    "malloc: %s", pcap_strerror(errno));
139 		(void)close(fd6);
140 		(void)close(fd4);
141 		return (-1);
142 	}
143 
144 	/*
145 	 * Get the entries.
146 	 */
147 	ifc.lifc_len = buf_size;
148 	ifc.lifc_buf = buf;
149 	ifc.lifc_family = AF_UNSPEC;
150 	ifc.lifc_flags = 0;
151 	memset(buf, 0, buf_size);
152 	if (ioctl(fd4, SIOCGLIFCONF, (char *)&ifc) < 0) {
153 		(void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
154 		    "SIOCGLIFCONF: %s", pcap_strerror(errno));
155 		(void)close(fd6);
156 		(void)close(fd4);
157 		free(buf);
158 		return (-1);
159 	}
160 
161 	/*
162 	 * Loop over the entries.
163 	 */
164 	ifrp = (struct lifreq *)buf;
165 	ifend = (struct lifreq *)(buf + ifc.lifc_len);
166 
167 	for (; ifrp < ifend; ifrp++) {
168 		/*
169 		 * Skip entries that begin with "dummy".
170 		 * XXX - what are these?  Is this Linux-specific?
171 		 * Are there platforms on which we shouldn't do this?
172 		 */
173 		if (strncmp(ifrp->lifr_name, "dummy", 5) == 0)
174 			continue;
175 
176 		/*
177 		 * Can we capture on this device?
178 		 */
179 		if (!(*check_usable)(ifrp->lifr_name)) {
180 			/*
181 			 * No.
182 			 */
183 			continue;
184 		}
185 
186 		/*
187 		 * IPv6 or not?
188 		 */
189 		if (((struct sockaddr *)&ifrp->lifr_addr)->sa_family == AF_INET6)
190 			fd = fd6;
191 		else
192 			fd = fd4;
193 
194 		/*
195 		 * Get the flags for this interface.
196 		 */
197 		strncpy(ifrflags.lifr_name, ifrp->lifr_name,
198 		    sizeof(ifrflags.lifr_name));
199 		if (ioctl(fd, SIOCGLIFFLAGS, (char *)&ifrflags) < 0) {
200 			if (errno == ENXIO)
201 				continue;
202 			(void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
203 			    "SIOCGLIFFLAGS: %.*s: %s",
204 			    (int)sizeof(ifrflags.lifr_name),
205 			    ifrflags.lifr_name,
206 			    pcap_strerror(errno));
207 			ret = -1;
208 			break;
209 		}
210 
211 		/*
212 		 * Get the netmask for this address on this interface.
213 		 */
214 		strncpy(ifrnetmask.lifr_name, ifrp->lifr_name,
215 		    sizeof(ifrnetmask.lifr_name));
216 		memcpy(&ifrnetmask.lifr_addr, &ifrp->lifr_addr,
217 		    sizeof(ifrnetmask.lifr_addr));
218 		if (ioctl(fd, SIOCGLIFNETMASK, (char *)&ifrnetmask) < 0) {
219 			if (errno == EADDRNOTAVAIL) {
220 				/*
221 				 * Not available.
222 				 */
223 				netmask = NULL;
224 			} else {
225 				(void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
226 				    "SIOCGLIFNETMASK: %.*s: %s",
227 				    (int)sizeof(ifrnetmask.lifr_name),
228 				    ifrnetmask.lifr_name,
229 				    pcap_strerror(errno));
230 				ret = -1;
231 				break;
232 			}
233 		} else
234 			netmask = (struct sockaddr *)&ifrnetmask.lifr_addr;
235 
236 		/*
237 		 * Get the broadcast address for this address on this
238 		 * interface (if any).
239 		 */
240 		if (ifrflags.lifr_flags & IFF_BROADCAST) {
241 			strncpy(ifrbroadaddr.lifr_name, ifrp->lifr_name,
242 			    sizeof(ifrbroadaddr.lifr_name));
243 			memcpy(&ifrbroadaddr.lifr_addr, &ifrp->lifr_addr,
244 			    sizeof(ifrbroadaddr.lifr_addr));
245 			if (ioctl(fd, SIOCGLIFBRDADDR,
246 			    (char *)&ifrbroadaddr) < 0) {
247 				if (errno == EADDRNOTAVAIL) {
248 					/*
249 					 * Not available.
250 					 */
251 					broadaddr = NULL;
252 				} else {
253 					(void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
254 					    "SIOCGLIFBRDADDR: %.*s: %s",
255 					    (int)sizeof(ifrbroadaddr.lifr_name),
256 					    ifrbroadaddr.lifr_name,
257 					    pcap_strerror(errno));
258 					ret = -1;
259 					break;
260 				}
261 			} else
262 				broadaddr = (struct sockaddr *)&ifrbroadaddr.lifr_broadaddr;
263 		} else {
264 			/*
265 			 * Not a broadcast interface, so no broadcast
266 			 * address.
267 			 */
268 			broadaddr = NULL;
269 		}
270 
271 		/*
272 		 * Get the destination address for this address on this
273 		 * interface (if any).
274 		 */
275 		if (ifrflags.lifr_flags & IFF_POINTOPOINT) {
276 			strncpy(ifrdstaddr.lifr_name, ifrp->lifr_name,
277 			    sizeof(ifrdstaddr.lifr_name));
278 			memcpy(&ifrdstaddr.lifr_addr, &ifrp->lifr_addr,
279 			    sizeof(ifrdstaddr.lifr_addr));
280 			if (ioctl(fd, SIOCGLIFDSTADDR,
281 			    (char *)&ifrdstaddr) < 0) {
282 				if (errno == EADDRNOTAVAIL) {
283 					/*
284 					 * Not available.
285 					 */
286 					dstaddr = NULL;
287 				} else {
288 					(void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
289 					    "SIOCGLIFDSTADDR: %.*s: %s",
290 					    (int)sizeof(ifrdstaddr.lifr_name),
291 					    ifrdstaddr.lifr_name,
292 					    pcap_strerror(errno));
293 					ret = -1;
294 					break;
295 				}
296 			} else
297 				dstaddr = (struct sockaddr *)&ifrdstaddr.lifr_dstaddr;
298 		} else
299 			dstaddr = NULL;
300 
301 #ifdef HAVE_SOLARIS
302 		/*
303 		 * If this entry has a colon followed by a number at
304 		 * the end, it's a logical interface.  Those are just
305 		 * the way you assign multiple IP addresses to a real
306 		 * interface, so an entry for a logical interface should
307 		 * be treated like the entry for the real interface;
308 		 * we do that by stripping off the ":" and the number.
309 		 */
310 		p = strchr(ifrp->lifr_name, ':');
311 		if (p != NULL) {
312 			/*
313 			 * We have a ":"; is it followed by a number?
314 			 */
315 			q = p + 1;
316 			while (isdigit((unsigned char)*q))
317 				q++;
318 			if (*q == '\0') {
319 				/*
320 				 * All digits after the ":" until the end.
321 				 * Strip off the ":" and everything after
322 				 * it.
323 				 */
324 				*p = '\0';
325 			}
326 		}
327 #endif
328 
329 		/*
330 		 * Add information for this address to the list.
331 		 */
332 		if (add_addr_to_iflist(&devlist, ifrp->lifr_name,
333 		    if_flags_to_pcap_flags(ifrp->lifr_name, ifrflags.lifr_flags),
334 		    (struct sockaddr *)&ifrp->lifr_addr,
335 		    sizeof (struct sockaddr_storage),
336 		    netmask, sizeof (struct sockaddr_storage),
337 		    broadaddr, sizeof (struct sockaddr_storage),
338 		    dstaddr, sizeof (struct sockaddr_storage), errbuf) < 0) {
339 			ret = -1;
340 			break;
341 		}
342 	}
343 	free(buf);
344 	(void)close(fd6);
345 	(void)close(fd4);
346 
347 	if (ret == -1) {
348 		/*
349 		 * We had an error; free the list we've been constructing.
350 		 */
351 		if (devlist != NULL) {
352 			pcap_freealldevs(devlist);
353 			devlist = NULL;
354 		}
355 	}
356 
357 	*alldevsp = devlist;
358 	return (ret);
359 }
360