1 /* $OpenBSD: mc6route.c,v 1.2 2021/07/06 11:50:34 bluhm Exp $ */
2 /*
3 * Copyright (c) 2019 Alexander Bluhm <bluhm@openbsd.org>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17 /*
18 * Copyright (c) 1983, 1988, 1993
19 * The Regents of the University of California. All rights reserved.
20 *
21 * Redistribution and use in source and binary forms, with or without
22 * modification, are permitted provided that the following conditions
23 * are met:
24 * 1. Redistributions of source code must retain the above copyright
25 * notice, this list of conditions and the following disclaimer.
26 * 2. Redistributions in binary form must reproduce the above copyright
27 * notice, this list of conditions and the following disclaimer in the
28 * documentation and/or other materials provided with the distribution.
29 * 3. Neither the name of the University nor the names of its contributors
30 * may be used to endorse or promote products derived from this software
31 * without specific prior written permission.
32 *
33 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
34 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
35 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
36 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
37 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
38 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
39 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
40 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
41 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
42 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
43 * SUCH DAMAGE.
44 */
45
46 #include <sys/types.h>
47 #include <sys/socket.h>
48 #include <sys/sysctl.h>
49
50 #include <arpa/inet.h>
51 #include <net/if.h>
52 #include <netinet/in.h>
53 #include <netinet6/ip6_mroute.h>
54
55 #include <err.h>
56 #include <errno.h>
57 #include <fcntl.h>
58 #include <limits.h>
59 #include <signal.h>
60 #include <stdlib.h>
61 #include <stdio.h>
62 #include <string.h>
63 #include <time.h>
64 #include <unistd.h>
65
66 void __dead usage(void);
67 void sigexit(int);
68 size_t get_sysctl(const int *mib, u_int mcnt, char **buf);
69
70 void __dead
usage(void)71 usage(void)
72 {
73 fprintf(stderr,
74 "mc6route [-b] [-f file] [-g group] -i ifname [-n timeout] -o outname\n"
75 " [-r timeout]\n"
76 " -b fork to background after setup\n"
77 " -f file print message to log file, default stdout\n"
78 " -g group multicast group, default 224.0.0.123\n"
79 " -i ifname multicast interface address\n"
80 " -n timeout expect not to receive any message until timeout\n"
81 " -o outname outgoing interface address\n"
82 " -r timeout receive timeout in seconds\n");
83 exit(2);
84 }
85
86 int
main(int argc,char * argv[])87 main(int argc, char *argv[])
88 {
89 struct mif6ctl mif;
90 struct mf6cctl mfc;
91 struct mif6info *minfo;
92 FILE *log;
93 const char *errstr, *file, *group, *ifname, *outname;
94 char *buf;
95 size_t needed;
96 u_int64_t pktin, pktout;
97 int value, ch, s, fd, background, norecv;
98 unsigned int timeout;
99 pid_t pid;
100 int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_MRTMIF };
101
102 background = 0;
103 log = stdout;
104 file = NULL;
105 group = "ff04::123";
106 ifname = NULL;
107 norecv = 0;
108 outname = NULL;
109 timeout = 0;
110 while ((ch = getopt(argc, argv, "bf:g:i:n:o:r:")) != -1) {
111 switch (ch) {
112 case 'b':
113 background = 1;
114 break;
115 case 'f':
116 file = optarg;
117 break;
118 case 'g':
119 group = optarg;
120 break;
121 case 'i':
122 ifname = optarg;
123 break;
124 case 'n':
125 norecv = 1;
126 timeout = strtonum(optarg, 1, INT_MAX, &errstr);
127 if (errstr != NULL)
128 errx(1, "no timeout is %s: %s", errstr, optarg);
129 break;
130 case 'o':
131 outname = optarg;
132 break;
133 case 'r':
134 timeout = strtonum(optarg, 1, INT_MAX, &errstr);
135 if (errstr != NULL)
136 errx(1, "timeout is %s: %s", errstr, optarg);
137 break;
138 default:
139 usage();
140 }
141 }
142 argc -= optind;
143 argv += optind;
144 if (ifname == NULL)
145 errx(2, "no ifname");
146 if (outname == NULL)
147 errx(2, "no outname");
148 if (argc)
149 usage();
150
151 if (file != NULL) {
152 log = fopen(file, "w");
153 if (log == NULL)
154 err(1, "fopen %s", file);
155 }
156
157 s = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6);
158 if (s == -1)
159 err(1, "socket");
160 value = 1;
161 if (setsockopt(s, IPPROTO_IPV6, MRT6_INIT, &value, sizeof(value)) == -1)
162 err(1, "setsockopt MRT6_INIT");
163
164 memset(&mif, 0, sizeof(mif));
165 mif.mif6c_mifi = 0;
166 mif.mif6c_pifi = if_nametoindex(ifname);
167 if (mif.mif6c_pifi == 0)
168 err(1, "if_nametoindex %s", ifname);
169 if (setsockopt(s, IPPROTO_IPV6, MRT6_ADD_MIF, &mif, sizeof(mif)) == -1)
170 err(1, "setsockopt MRT6_ADD_MIF %s", ifname);
171
172 memset(&mif, 0, sizeof(mif));
173 mif.mif6c_mifi = 1;
174 mif.mif6c_pifi = if_nametoindex(outname);
175 if (mif.mif6c_pifi == 0)
176 err(1, "if_nametoindex %s", outname);
177 if (setsockopt(s, IPPROTO_IPV6, MRT6_ADD_MIF, &mif, sizeof(mif)) == -1)
178 err(1, "setsockopt MRT6_ADD_MIF %s", outname);
179
180 memset(&mfc, 0, sizeof(mfc));
181 if (inet_pton(AF_INET6, group, &mfc.mf6cc_mcastgrp.sin6_addr) == -1)
182 err(1, "inet_pton %s", group);
183 mfc.mf6cc_parent = 0;
184 IF_SET(1, &mfc.mf6cc_ifset);
185
186 if (setsockopt(s, IPPROTO_IPV6, MRT6_ADD_MFC, &mfc, sizeof(mfc)) == -1)
187 err(1, "setsockopt MRT6_ADD_MFC %s", ifname);
188
189 if (background) {
190 pid = fork();
191 switch (pid) {
192 case -1:
193 err(1, "fork");
194 case 0:
195 fd = open("/dev/null", O_RDWR);
196 if (fd == -1)
197 err(1, "open /dev/null");
198 if (dup2(fd, 0) == -1)
199 err(1, "dup 0");
200 if (dup2(fd, 1) == -1)
201 err(1, "dup 1");
202 if (dup2(fd, 2) == -1)
203 err(1, "dup 2");
204 break;
205 default:
206 _exit(0);
207 }
208 }
209
210 if (timeout) {
211 if (norecv) {
212 if (signal(SIGALRM, sigexit) == SIG_ERR)
213 err(1, "signal SIGALRM");
214 }
215 alarm(timeout);
216 }
217
218 buf = NULL;
219 pktin = pktout = 0;
220 do {
221 struct timespec sleeptime = { 0, 10000000 };
222
223 if (nanosleep(&sleeptime, NULL) == -1)
224 err(1, "nanosleep");
225 needed = get_sysctl(mib, sizeof(mib) / sizeof(mib[0]), &buf);
226 for (minfo = (struct mif6info *)buf;
227 (char *)minfo < buf + needed;
228 minfo++) {
229 switch (minfo->m6_ifindex) {
230 case 0:
231 if (pktin != minfo->m6_pkt_in) {
232 fprintf(log, "<<< %llu\n",
233 minfo->m6_pkt_in);
234 fflush(log);
235 }
236 pktin = minfo->m6_pkt_in;
237 break;
238 case 1:
239 if (pktout != minfo->m6_pkt_out) {
240 fprintf(log, ">>> %llu\n",
241 minfo->m6_pkt_out);
242 fflush(log);
243 }
244 pktout = minfo->m6_pkt_out;
245 break;
246 }
247 }
248 } while (pktin == 0 || pktout == 0);
249 free(buf);
250
251 if (norecv)
252 errx(1, "pktin %llu, pktout %llu", pktin, pktout);
253
254 return 0;
255 }
256
257 void
sigexit(int sig)258 sigexit(int sig)
259 {
260 _exit(0);
261 }
262
263 /* from netstat(8) */
264 size_t
get_sysctl(const int * mib,u_int mcnt,char ** buf)265 get_sysctl(const int *mib, u_int mcnt, char **buf)
266 {
267 size_t needed;
268
269 while (1) {
270 if (sysctl(mib, mcnt, NULL, &needed, NULL, 0) == -1)
271 err(1, "sysctl-estimate");
272 if (needed == 0)
273 break;
274 if ((*buf = realloc(*buf, needed)) == NULL)
275 err(1, NULL);
276 if (sysctl(mib, mcnt, *buf, &needed, NULL, 0) == -1) {
277 if (errno == ENOMEM)
278 continue;
279 err(1, "sysctl");
280 }
281 break;
282 }
283
284 return needed;
285 }
286