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
pcap_findalldevs_interfaces(pcap_if_t ** alldevsp,char * errbuf)78 pcap_findalldevs_interfaces(pcap_if_t **alldevsp, char *errbuf)
79 {
80 	pcap_if_t *devlist = NULL;
81 	register int fd4, fd6, fd;
82 	register struct lifreq *ifrp, *ifend;
83 	struct lifnum ifn;
84 	struct lifconf ifc;
85 	char *buf = NULL;
86 	unsigned buf_size;
87 #ifdef HAVE_SOLARIS
88 	char *p, *q;
89 #endif
90 	struct lifreq ifrflags, ifrnetmask, ifrbroadaddr, ifrdstaddr;
91 	struct sockaddr *netmask, *broadaddr, *dstaddr;
92 	int ret = 0;
93 
94 	/*
95 	 * Create a socket from which to fetch the list of interfaces,
96 	 * and from which to fetch IPv4 information.
97 	 */
98 	fd4 = socket(AF_INET, SOCK_DGRAM, 0);
99 	if (fd4 < 0) {
100 		(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
101 		    "socket: %s", pcap_strerror(errno));
102 		return (-1);
103 	}
104 
105 	/*
106 	 * Create a socket from which to fetch IPv6 information.
107 	 */
108 	fd6 = socket(AF_INET6, SOCK_DGRAM, 0);
109 	if (fd6 < 0) {
110 		(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
111 		    "socket: %s", pcap_strerror(errno));
112 		(void)close(fd4);
113 		return (-1);
114 	}
115 
116 	/*
117 	 * How many entries will SIOCGLIFCONF return?
118 	 */
119 	ifn.lifn_family = AF_UNSPEC;
120 	ifn.lifn_flags = 0;
121 	ifn.lifn_count = 0;
122 	if (ioctl(fd4, SIOCGLIFNUM, (char *)&ifn) < 0) {
123 		(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
124 		    "SIOCGLIFNUM: %s", pcap_strerror(errno));
125 		(void)close(fd6);
126 		(void)close(fd4);
127 		return (-1);
128 	}
129 
130 	/*
131 	 * Allocate a buffer for those entries.
132 	 */
133 	buf_size = ifn.lifn_count * sizeof (struct lifreq);
134 	buf = malloc(buf_size);
135 	if (buf == NULL) {
136 		(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
137 		    "malloc: %s", pcap_strerror(errno));
138 		(void)close(fd6);
139 		(void)close(fd4);
140 		return (-1);
141 	}
142 
143 	/*
144 	 * Get the entries.
145 	 */
146 	ifc.lifc_len = buf_size;
147 	ifc.lifc_buf = buf;
148 	ifc.lifc_family = AF_UNSPEC;
149 	ifc.lifc_flags = 0;
150 	memset(buf, 0, buf_size);
151 	if (ioctl(fd4, SIOCGLIFCONF, (char *)&ifc) < 0) {
152 		(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
153 		    "SIOCGLIFCONF: %s", pcap_strerror(errno));
154 		(void)close(fd6);
155 		(void)close(fd4);
156 		free(buf);
157 		return (-1);
158 	}
159 
160 	/*
161 	 * Loop over the entries.
162 	 */
163 	ifrp = (struct lifreq *)buf;
164 	ifend = (struct lifreq *)(buf + ifc.lifc_len);
165 
166 	for (; ifrp < ifend; ifrp++) {
167 		/*
168 		 * IPv6 or not?
169 		 */
170 		if (((struct sockaddr *)&ifrp->lifr_addr)->sa_family == AF_INET6)
171 			fd = fd6;
172 		else
173 			fd = fd4;
174 
175 		/*
176 		 * Skip entries that begin with "dummy".
177 		 * XXX - what are these?  Is this Linux-specific?
178 		 * Are there platforms on which we shouldn't do this?
179 		 */
180 		if (strncmp(ifrp->lifr_name, "dummy", 5) == 0)
181 			continue;
182 
183 #ifdef HAVE_SOLARIS
184 		/*
185 		 * Skip entries that have a ":" followed by a number
186 		 * at the end - those are Solaris virtual interfaces
187 		 * on which you can't capture.
188 		 */
189 		p = strchr(ifrp->lifr_name, ':');
190 		if (p != NULL) {
191 			/*
192 			 * We have a ":"; is it followed by a number?
193 			 */
194 			while (isdigit((unsigned char)*p))
195 				p++;
196 			if (*p == '\0') {
197 				/*
198 				 * All digits after the ":" until the end.
199 				 */
200 				continue;
201 			}
202 		}
203 #endif
204 
205 		/*
206 		 * Get the flags for this interface.
207 		 */
208 		strncpy(ifrflags.lifr_name, ifrp->lifr_name,
209 		    sizeof(ifrflags.lifr_name));
210 		if (ioctl(fd, SIOCGLIFFLAGS, (char *)&ifrflags) < 0) {
211 			if (errno == ENXIO)
212 				continue;
213 			(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
214 			    "SIOCGLIFFLAGS: %.*s: %s",
215 			    (int)sizeof(ifrflags.lifr_name),
216 			    ifrflags.lifr_name,
217 			    pcap_strerror(errno));
218 			ret = -1;
219 			break;
220 		}
221 
222 		/*
223 		 * Get the netmask for this address on this interface.
224 		 */
225 		strncpy(ifrnetmask.lifr_name, ifrp->lifr_name,
226 		    sizeof(ifrnetmask.lifr_name));
227 		memcpy(&ifrnetmask.lifr_addr, &ifrp->lifr_addr,
228 		    sizeof(ifrnetmask.lifr_addr));
229 		if (ioctl(fd, SIOCGLIFNETMASK, (char *)&ifrnetmask) < 0) {
230 			if (errno == EADDRNOTAVAIL) {
231 				/*
232 				 * Not available.
233 				 */
234 				netmask = NULL;
235 			} else {
236 				(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
237 				    "SIOCGLIFNETMASK: %.*s: %s",
238 				    (int)sizeof(ifrnetmask.lifr_name),
239 				    ifrnetmask.lifr_name,
240 				    pcap_strerror(errno));
241 				ret = -1;
242 				break;
243 			}
244 		} else
245 			netmask = (struct sockaddr *)&ifrnetmask.lifr_addr;
246 
247 		/*
248 		 * Get the broadcast address for this address on this
249 		 * interface (if any).
250 		 */
251 		if (ifrflags.lifr_flags & IFF_BROADCAST) {
252 			strncpy(ifrbroadaddr.lifr_name, ifrp->lifr_name,
253 			    sizeof(ifrbroadaddr.lifr_name));
254 			memcpy(&ifrbroadaddr.lifr_addr, &ifrp->lifr_addr,
255 			    sizeof(ifrbroadaddr.lifr_addr));
256 			if (ioctl(fd, SIOCGLIFBRDADDR,
257 			    (char *)&ifrbroadaddr) < 0) {
258 				if (errno == EADDRNOTAVAIL) {
259 					/*
260 					 * Not available.
261 					 */
262 					broadaddr = NULL;
263 				} else {
264 					(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
265 					    "SIOCGLIFBRDADDR: %.*s: %s",
266 					    (int)sizeof(ifrbroadaddr.lifr_name),
267 					    ifrbroadaddr.lifr_name,
268 					    pcap_strerror(errno));
269 					ret = -1;
270 					break;
271 				}
272 			} else
273 				broadaddr = (struct sockaddr *)&ifrbroadaddr.lifr_broadaddr;
274 		} else {
275 			/*
276 			 * Not a broadcast interface, so no broadcast
277 			 * address.
278 			 */
279 			broadaddr = NULL;
280 		}
281 
282 		/*
283 		 * Get the destination address for this address on this
284 		 * interface (if any).
285 		 */
286 		if (ifrflags.lifr_flags & IFF_POINTOPOINT) {
287 			strncpy(ifrdstaddr.lifr_name, ifrp->lifr_name,
288 			    sizeof(ifrdstaddr.lifr_name));
289 			memcpy(&ifrdstaddr.lifr_addr, &ifrp->lifr_addr,
290 			    sizeof(ifrdstaddr.lifr_addr));
291 			if (ioctl(fd, SIOCGLIFDSTADDR,
292 			    (char *)&ifrdstaddr) < 0) {
293 				if (errno == EADDRNOTAVAIL) {
294 					/*
295 					 * Not available.
296 					 */
297 					dstaddr = NULL;
298 				} else {
299 					(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
300 					    "SIOCGLIFDSTADDR: %.*s: %s",
301 					    (int)sizeof(ifrdstaddr.lifr_name),
302 					    ifrdstaddr.lifr_name,
303 					    pcap_strerror(errno));
304 					ret = -1;
305 					break;
306 				}
307 			} else
308 				dstaddr = (struct sockaddr *)&ifrdstaddr.lifr_dstaddr;
309 		} else
310 			dstaddr = NULL;
311 
312 #ifdef HAVE_SOLARIS
313 		/*
314 		 * If this entry has a colon followed by a number at
315 		 * the end, it's a logical interface.  Those are just
316 		 * the way you assign multiple IP addresses to a real
317 		 * interface, so an entry for a logical interface should
318 		 * be treated like the entry for the real interface;
319 		 * we do that by stripping off the ":" and the number.
320 		 */
321 		p = strchr(ifrp->lifr_name, ':');
322 		if (p != NULL) {
323 			/*
324 			 * We have a ":"; is it followed by a number?
325 			 */
326 			q = p + 1;
327 			while (isdigit((unsigned char)*q))
328 				q++;
329 			if (*q == '\0') {
330 				/*
331 				 * All digits after the ":" until the end.
332 				 * Strip off the ":" and everything after
333 				 * it.
334 				 */
335 				*p = '\0';
336 			}
337 		}
338 #endif
339 
340 		/*
341 		 * Add information for this address to the list.
342 		 */
343 		if (add_addr_to_iflist(&devlist, ifrp->lifr_name,
344 		    ifrflags.lifr_flags, (struct sockaddr *)&ifrp->lifr_addr,
345 		    sizeof (struct sockaddr_storage),
346 		    netmask, sizeof (struct sockaddr_storage),
347 		    broadaddr, sizeof (struct sockaddr_storage),
348 		    dstaddr, sizeof (struct sockaddr_storage), errbuf) < 0) {
349 			ret = -1;
350 			break;
351 		}
352 	}
353 	free(buf);
354 	(void)close(fd6);
355 	(void)close(fd4);
356 
357 	if (ret == -1) {
358 		/*
359 		 * We had an error; free the list we've been constructing.
360 		 */
361 		if (devlist != NULL) {
362 			pcap_freealldevs(devlist);
363 			devlist = NULL;
364 		}
365 	}
366 
367 	*alldevsp = devlist;
368 	return (ret);
369 }
370