xref: /freebsd/contrib/libpcap/fad-glifc.c (revision a7623790fb345e6dc986dfd31df0ace115e6f2e4)
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_list_t *devlistp, char *errbuf,
79     int (*check_usable)(const char *), get_if_flags_func get_flags_func)
80 {
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 		pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,
101 		    errno, "socket: AF_INET");
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 		pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,
111 		    errno, "socket: AF_INET6");
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 		pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,
124 		    errno, "SIOCGLIFNUM");
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 		pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,
137 		    errno, "malloc");
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 		pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,
153 		    errno, "SIOCGLIFCONF");
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 		 * Skip entries that begin with "dummy".
169 		 * XXX - what are these?  Is this Linux-specific?
170 		 * Are there platforms on which we shouldn't do this?
171 		 */
172 		if (strncmp(ifrp->lifr_name, "dummy", 5) == 0)
173 			continue;
174 
175 		/*
176 		 * Can we capture on this device?
177 		 */
178 		if (!(*check_usable)(ifrp->lifr_name)) {
179 			/*
180 			 * No.
181 			 */
182 			continue;
183 		}
184 
185 		/*
186 		 * IPv6 or not?
187 		 */
188 		if (((struct sockaddr *)&ifrp->lifr_addr)->sa_family == AF_INET6)
189 			fd = fd6;
190 		else
191 			fd = fd4;
192 
193 		/*
194 		 * Get the flags for this interface.
195 		 */
196 		strncpy(ifrflags.lifr_name, ifrp->lifr_name,
197 		    sizeof(ifrflags.lifr_name));
198 		if (ioctl(fd, SIOCGLIFFLAGS, (char *)&ifrflags) < 0) {
199 			if (errno == ENXIO)
200 				continue;
201 			pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,
202 			    errno, "SIOCGLIFFLAGS: %.*s",
203 			    (int)sizeof(ifrflags.lifr_name),
204 			    ifrflags.lifr_name);
205 			ret = -1;
206 			break;
207 		}
208 
209 		/*
210 		 * Get the netmask for this address on this interface.
211 		 */
212 		strncpy(ifrnetmask.lifr_name, ifrp->lifr_name,
213 		    sizeof(ifrnetmask.lifr_name));
214 		memcpy(&ifrnetmask.lifr_addr, &ifrp->lifr_addr,
215 		    sizeof(ifrnetmask.lifr_addr));
216 		if (ioctl(fd, SIOCGLIFNETMASK, (char *)&ifrnetmask) < 0) {
217 			if (errno == EADDRNOTAVAIL) {
218 				/*
219 				 * Not available.
220 				 */
221 				netmask = NULL;
222 			} else {
223 				pcap_fmt_errmsg_for_errno(errbuf,
224 				    PCAP_ERRBUF_SIZE, errno,
225 				    "SIOCGLIFNETMASK: %.*s",
226 				    (int)sizeof(ifrnetmask.lifr_name),
227 				    ifrnetmask.lifr_name);
228 				ret = -1;
229 				break;
230 			}
231 		} else
232 			netmask = (struct sockaddr *)&ifrnetmask.lifr_addr;
233 
234 		/*
235 		 * Get the broadcast address for this address on this
236 		 * interface (if any).
237 		 */
238 		if (ifrflags.lifr_flags & IFF_BROADCAST) {
239 			strncpy(ifrbroadaddr.lifr_name, ifrp->lifr_name,
240 			    sizeof(ifrbroadaddr.lifr_name));
241 			memcpy(&ifrbroadaddr.lifr_addr, &ifrp->lifr_addr,
242 			    sizeof(ifrbroadaddr.lifr_addr));
243 			if (ioctl(fd, SIOCGLIFBRDADDR,
244 			    (char *)&ifrbroadaddr) < 0) {
245 				if (errno == EADDRNOTAVAIL) {
246 					/*
247 					 * Not available.
248 					 */
249 					broadaddr = NULL;
250 				} else {
251 					pcap_fmt_errmsg_for_errno(errbuf,
252 					    PCAP_ERRBUF_SIZE, errno,
253 					    "SIOCGLIFBRDADDR: %.*s",
254 					    (int)sizeof(ifrbroadaddr.lifr_name),
255 					    ifrbroadaddr.lifr_name);
256 					ret = -1;
257 					break;
258 				}
259 			} else
260 				broadaddr = (struct sockaddr *)&ifrbroadaddr.lifr_broadaddr;
261 		} else {
262 			/*
263 			 * Not a broadcast interface, so no broadcast
264 			 * address.
265 			 */
266 			broadaddr = NULL;
267 		}
268 
269 		/*
270 		 * Get the destination address for this address on this
271 		 * interface (if any).
272 		 */
273 		if (ifrflags.lifr_flags & IFF_POINTOPOINT) {
274 			strncpy(ifrdstaddr.lifr_name, ifrp->lifr_name,
275 			    sizeof(ifrdstaddr.lifr_name));
276 			memcpy(&ifrdstaddr.lifr_addr, &ifrp->lifr_addr,
277 			    sizeof(ifrdstaddr.lifr_addr));
278 			if (ioctl(fd, SIOCGLIFDSTADDR,
279 			    (char *)&ifrdstaddr) < 0) {
280 				if (errno == EADDRNOTAVAIL) {
281 					/*
282 					 * Not available.
283 					 */
284 					dstaddr = NULL;
285 				} else {
286 					pcap_fmt_errmsg_for_errno(errbuf,
287 					    PCAP_ERRBUF_SIZE, errno,
288 					    "SIOCGLIFDSTADDR: %.*s",
289 					    (int)sizeof(ifrdstaddr.lifr_name),
290 					    ifrdstaddr.lifr_name);
291 					ret = -1;
292 					break;
293 				}
294 			} else
295 				dstaddr = (struct sockaddr *)&ifrdstaddr.lifr_dstaddr;
296 		} else
297 			dstaddr = NULL;
298 
299 #ifdef HAVE_SOLARIS
300 		/*
301 		 * If this entry has a colon followed by a number at
302 		 * the end, it's a logical interface.  Those are just
303 		 * the way you assign multiple IP addresses to a real
304 		 * interface, so an entry for a logical interface should
305 		 * be treated like the entry for the real interface;
306 		 * we do that by stripping off the ":" and the number.
307 		 */
308 		p = strchr(ifrp->lifr_name, ':');
309 		if (p != NULL) {
310 			/*
311 			 * We have a ":"; is it followed by a number?
312 			 */
313 			q = p + 1;
314 			while (isdigit((unsigned char)*q))
315 				q++;
316 			if (*q == '\0') {
317 				/*
318 				 * All digits after the ":" until the end.
319 				 * Strip off the ":" and everything after
320 				 * it.
321 				 */
322 				*p = '\0';
323 			}
324 		}
325 #endif
326 
327 		/*
328 		 * Add information for this address to the list.
329 		 */
330 		if (add_addr_to_if(devlistp, ifrp->lifr_name,
331 		    ifrflags.lifr_flags, get_flags_func,
332 		    (struct sockaddr *)&ifrp->lifr_addr,
333 		    sizeof (struct sockaddr_storage),
334 		    netmask, sizeof (struct sockaddr_storage),
335 		    broadaddr, sizeof (struct sockaddr_storage),
336 		    dstaddr, sizeof (struct sockaddr_storage), errbuf) < 0) {
337 			ret = -1;
338 			break;
339 		}
340 	}
341 	free(buf);
342 	(void)close(fd6);
343 	(void)close(fd4);
344 
345 	return (ret);
346 }
347