xref: /freebsd/contrib/libpcap/fad-glifc.c (revision f81cdf24ba5436367377f7c8e8f51f6df2a75ca7)
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 <errno.h>
54 #include <memory.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <string.h>
58 #include <unistd.h>
59 
60 #include "pcap-int.h"
61 
62 #ifdef HAVE_OS_PROTO_H
63 #include "os-proto.h"
64 #endif
65 
66 /*
67  * Get a list of all interfaces that are up and that we can open.
68  * Returns -1 on error, 0 otherwise.
69  * The list, as returned through "alldevsp", may be null if no interfaces
70  * were up and could be opened.
71  *
72  * This is the implementation used on platforms that have SIOCGLIFCONF
73  * but don't have "getifaddrs()".  (Solaris 8 and later; we use
74  * SIOCGLIFCONF rather than SIOCGIFCONF in order to get IPv6 addresses.)
75  */
76 int
77 pcap_findalldevs_interfaces(pcap_if_list_t *devlistp, char *errbuf,
78     int (*check_usable)(const char *), get_if_flags_func get_flags_func)
79 {
80 	register int fd4, fd6, fd;
81 	register struct lifreq *ifrp, *ifend;
82 	struct lifnum ifn;
83 	struct lifconf ifc;
84 	char *buf = NULL;
85 	unsigned buf_size;
86 #ifdef HAVE_SOLARIS
87 	char *p, *q;
88 #endif
89 	struct lifreq ifrflags, ifrnetmask, ifrbroadaddr, ifrdstaddr;
90 	struct sockaddr *netmask, *broadaddr, *dstaddr;
91 	int ret = 0;
92 
93 	/*
94 	 * Create a socket from which to fetch the list of interfaces,
95 	 * and from which to fetch IPv4 information.
96 	 */
97 	fd4 = socket(AF_INET, SOCK_DGRAM, 0);
98 	if (fd4 < 0) {
99 		pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,
100 		    errno, "socket: AF_INET");
101 		return (-1);
102 	}
103 
104 	/*
105 	 * Create a socket from which to fetch IPv6 information.
106 	 */
107 	fd6 = socket(AF_INET6, SOCK_DGRAM, 0);
108 	if (fd6 < 0) {
109 		pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,
110 		    errno, "socket: AF_INET6");
111 		(void)close(fd4);
112 		return (-1);
113 	}
114 
115 	/*
116 	 * How many entries will SIOCGLIFCONF return?
117 	 */
118 	ifn.lifn_family = AF_UNSPEC;
119 	ifn.lifn_flags = 0;
120 	ifn.lifn_count = 0;
121 	if (ioctl(fd4, SIOCGLIFNUM, (char *)&ifn) < 0) {
122 		pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,
123 		    errno, "SIOCGLIFNUM");
124 		(void)close(fd6);
125 		(void)close(fd4);
126 		return (-1);
127 	}
128 
129 	/*
130 	 * Allocate a buffer for those entries.
131 	 */
132 	buf_size = ifn.lifn_count * sizeof (struct lifreq);
133 	buf = malloc(buf_size);
134 	if (buf == NULL) {
135 		pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,
136 		    errno, "malloc");
137 		(void)close(fd6);
138 		(void)close(fd4);
139 		return (-1);
140 	}
141 
142 	/*
143 	 * Get the entries.
144 	 */
145 	ifc.lifc_len = buf_size;
146 	ifc.lifc_buf = buf;
147 	ifc.lifc_family = AF_UNSPEC;
148 	ifc.lifc_flags = 0;
149 	memset(buf, 0, buf_size);
150 	if (ioctl(fd4, SIOCGLIFCONF, (char *)&ifc) < 0) {
151 		pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,
152 		    errno, "SIOCGLIFCONF");
153 		(void)close(fd6);
154 		(void)close(fd4);
155 		free(buf);
156 		return (-1);
157 	}
158 
159 	/*
160 	 * Loop over the entries.
161 	 */
162 	ifrp = (struct lifreq *)buf;
163 	ifend = (struct lifreq *)(buf + ifc.lifc_len);
164 
165 	for (; ifrp < ifend; ifrp++) {
166 		/*
167 		 * Skip entries that begin with "dummy".
168 		 * XXX - what are these?  Is this Linux-specific?
169 		 * Are there platforms on which we shouldn't do this?
170 		 */
171 		if (strncmp(ifrp->lifr_name, "dummy", 5) == 0)
172 			continue;
173 
174 		/*
175 		 * Can we capture on this device?
176 		 */
177 		if (!(*check_usable)(ifrp->lifr_name)) {
178 			/*
179 			 * No.
180 			 */
181 			continue;
182 		}
183 
184 		/*
185 		 * IPv6 or not?
186 		 */
187 		if (((struct sockaddr *)&ifrp->lifr_addr)->sa_family == AF_INET6)
188 			fd = fd6;
189 		else
190 			fd = fd4;
191 
192 		/*
193 		 * Get the flags for this interface.
194 		 */
195 		strncpy(ifrflags.lifr_name, ifrp->lifr_name,
196 		    sizeof(ifrflags.lifr_name));
197 		if (ioctl(fd, SIOCGLIFFLAGS, (char *)&ifrflags) < 0) {
198 			if (errno == ENXIO)
199 				continue;
200 			pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,
201 			    errno, "SIOCGLIFFLAGS: %.*s",
202 			    (int)sizeof(ifrflags.lifr_name),
203 			    ifrflags.lifr_name);
204 			ret = -1;
205 			break;
206 		}
207 
208 		/*
209 		 * Get the netmask for this address on this interface.
210 		 */
211 		strncpy(ifrnetmask.lifr_name, ifrp->lifr_name,
212 		    sizeof(ifrnetmask.lifr_name));
213 		memcpy(&ifrnetmask.lifr_addr, &ifrp->lifr_addr,
214 		    sizeof(ifrnetmask.lifr_addr));
215 		if (ioctl(fd, SIOCGLIFNETMASK, (char *)&ifrnetmask) < 0) {
216 			if (errno == EADDRNOTAVAIL) {
217 				/*
218 				 * Not available.
219 				 */
220 				netmask = NULL;
221 			} else {
222 				pcap_fmt_errmsg_for_errno(errbuf,
223 				    PCAP_ERRBUF_SIZE, errno,
224 				    "SIOCGLIFNETMASK: %.*s",
225 				    (int)sizeof(ifrnetmask.lifr_name),
226 				    ifrnetmask.lifr_name);
227 				ret = -1;
228 				break;
229 			}
230 		} else
231 			netmask = (struct sockaddr *)&ifrnetmask.lifr_addr;
232 
233 		/*
234 		 * Get the broadcast address for this address on this
235 		 * interface (if any).
236 		 */
237 		if (ifrflags.lifr_flags & IFF_BROADCAST) {
238 			strncpy(ifrbroadaddr.lifr_name, ifrp->lifr_name,
239 			    sizeof(ifrbroadaddr.lifr_name));
240 			memcpy(&ifrbroadaddr.lifr_addr, &ifrp->lifr_addr,
241 			    sizeof(ifrbroadaddr.lifr_addr));
242 			if (ioctl(fd, SIOCGLIFBRDADDR,
243 			    (char *)&ifrbroadaddr) < 0) {
244 				if (errno == EADDRNOTAVAIL) {
245 					/*
246 					 * Not available.
247 					 */
248 					broadaddr = NULL;
249 				} else {
250 					pcap_fmt_errmsg_for_errno(errbuf,
251 					    PCAP_ERRBUF_SIZE, errno,
252 					    "SIOCGLIFBRDADDR: %.*s",
253 					    (int)sizeof(ifrbroadaddr.lifr_name),
254 					    ifrbroadaddr.lifr_name);
255 					ret = -1;
256 					break;
257 				}
258 			} else
259 				broadaddr = (struct sockaddr *)&ifrbroadaddr.lifr_broadaddr;
260 		} else {
261 			/*
262 			 * Not a broadcast interface, so no broadcast
263 			 * address.
264 			 */
265 			broadaddr = NULL;
266 		}
267 
268 		/*
269 		 * Get the destination address for this address on this
270 		 * interface (if any).
271 		 */
272 		if (ifrflags.lifr_flags & IFF_POINTOPOINT) {
273 			strncpy(ifrdstaddr.lifr_name, ifrp->lifr_name,
274 			    sizeof(ifrdstaddr.lifr_name));
275 			memcpy(&ifrdstaddr.lifr_addr, &ifrp->lifr_addr,
276 			    sizeof(ifrdstaddr.lifr_addr));
277 			if (ioctl(fd, SIOCGLIFDSTADDR,
278 			    (char *)&ifrdstaddr) < 0) {
279 				if (errno == EADDRNOTAVAIL) {
280 					/*
281 					 * Not available.
282 					 */
283 					dstaddr = NULL;
284 				} else {
285 					pcap_fmt_errmsg_for_errno(errbuf,
286 					    PCAP_ERRBUF_SIZE, errno,
287 					    "SIOCGLIFDSTADDR: %.*s",
288 					    (int)sizeof(ifrdstaddr.lifr_name),
289 					    ifrdstaddr.lifr_name);
290 					ret = -1;
291 					break;
292 				}
293 			} else
294 				dstaddr = (struct sockaddr *)&ifrdstaddr.lifr_dstaddr;
295 		} else
296 			dstaddr = NULL;
297 
298 #ifdef HAVE_SOLARIS
299 		/*
300 		 * If this entry has a colon followed by a number at
301 		 * the end, it's a logical interface.  Those are just
302 		 * the way you assign multiple IP addresses to a real
303 		 * interface, so an entry for a logical interface should
304 		 * be treated like the entry for the real interface;
305 		 * we do that by stripping off the ":" and the number.
306 		 */
307 		p = strchr(ifrp->lifr_name, ':');
308 		if (p != NULL) {
309 			/*
310 			 * We have a ":"; is it followed by a number?
311 			 */
312 			q = p + 1;
313 			while (PCAP_ISDIGIT(*q))
314 				q++;
315 			if (*q == '\0') {
316 				/*
317 				 * All digits after the ":" until the end.
318 				 * Strip off the ":" and everything after
319 				 * it.
320 				 */
321 				*p = '\0';
322 			}
323 		}
324 #endif
325 
326 		/*
327 		 * Add information for this address to the list.
328 		 */
329 		if (add_addr_to_if(devlistp, ifrp->lifr_name,
330 		    ifrflags.lifr_flags, get_flags_func,
331 		    (struct sockaddr *)&ifrp->lifr_addr,
332 		    sizeof (struct sockaddr_storage),
333 		    netmask, sizeof (struct sockaddr_storage),
334 		    broadaddr, sizeof (struct sockaddr_storage),
335 		    dstaddr, sizeof (struct sockaddr_storage), errbuf) < 0) {
336 			ret = -1;
337 			break;
338 		}
339 	}
340 	free(buf);
341 	(void)close(fd6);
342 	(void)close(fd4);
343 
344 	return (ret);
345 }
346