1 /* $OpenBSD: mcroute.c,v 1.3 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 <netinet/in.h>
52 #include <netinet/ip_mroute.h>
53
54 #include <err.h>
55 #include <errno.h>
56 #include <fcntl.h>
57 #include <limits.h>
58 #include <signal.h>
59 #include <stdlib.h>
60 #include <stdio.h>
61 #include <string.h>
62 #include <time.h>
63 #include <unistd.h>
64
65 void __dead usage(void);
66 void sigexit(int);
67 size_t get_sysctl(const int *mib, u_int mcnt, char **buf);
68
69 void __dead
usage(void)70 usage(void)
71 {
72 fprintf(stderr,
73 "mcroute [-b] [-f file] [-g group] -i ifaddr [-n timeout] -o outaddr\n"
74 " [-r timeout]\n"
75 " -b fork to background after setup\n"
76 " -f file print message to log file, default stdout\n"
77 " -g group multicast group, default 224.0.0.123\n"
78 " -i ifaddr multicast interface address\n"
79 " -n timeout expect not to receive any message until timeout\n"
80 " -o outaddr outgoing interface address\n"
81 " -r timeout receive timeout in seconds\n");
82 exit(2);
83 }
84
85 int
main(int argc,char * argv[])86 main(int argc, char *argv[])
87 {
88 struct vifctl vif;
89 struct mfcctl mfc;
90 struct vifinfo *vinfo;
91 FILE *log;
92 const char *errstr, *file, *group, *ifaddr, *outaddr;
93 char *buf;
94 size_t needed;
95 unsigned long pktin, pktout;
96 int value, ch, s, fd, background, norecv;
97 unsigned int timeout;
98 pid_t pid;
99 int mib[] = { CTL_NET, PF_INET, IPPROTO_IP, IPCTL_MRTVIF };
100
101 background = 0;
102 log = stdout;
103 file = NULL;
104 group = "224.0.1.123";
105 ifaddr = NULL;
106 norecv = 0;
107 outaddr = NULL;
108 timeout = 0;
109 while ((ch = getopt(argc, argv, "bf:g:i:n:o:r:")) != -1) {
110 switch (ch) {
111 case 'b':
112 background = 1;
113 break;
114 case 'f':
115 file = optarg;
116 break;
117 case 'g':
118 group = optarg;
119 break;
120 case 'i':
121 ifaddr = optarg;
122 break;
123 case 'n':
124 norecv = 1;
125 timeout = strtonum(optarg, 1, INT_MAX, &errstr);
126 if (errstr != NULL)
127 errx(1, "no timeout is %s: %s", errstr, optarg);
128 break;
129 case 'o':
130 outaddr = optarg;
131 break;
132 case 'r':
133 timeout = strtonum(optarg, 1, INT_MAX, &errstr);
134 if (errstr != NULL)
135 errx(1, "timeout is %s: %s", errstr, optarg);
136 break;
137 default:
138 usage();
139 }
140 }
141 argc -= optind;
142 argv += optind;
143 if (ifaddr == NULL)
144 errx(2, "no ifaddr");
145 if (outaddr == NULL)
146 errx(2, "no outaddr");
147 if (argc)
148 usage();
149
150 if (file != NULL) {
151 log = fopen(file, "w");
152 if (log == NULL)
153 err(1, "fopen %s", file);
154 }
155
156 s = socket(AF_INET, SOCK_RAW, IPPROTO_IGMP);
157 if (s == -1)
158 err(1, "socket");
159 value = 1;
160 if (setsockopt(s, IPPROTO_IP, MRT_INIT, &value, sizeof(value)) == -1)
161 err(1, "setsockopt MRT_INIT");
162
163 memset(&vif, 0, sizeof(vif));
164 vif.vifc_vifi = 0;
165 if (inet_pton(AF_INET, ifaddr, &vif.vifc_lcl_addr) == -1)
166 err(1, "inet_pton %s", ifaddr);
167 if (setsockopt(s, IPPROTO_IP, MRT_ADD_VIF, &vif, sizeof(vif)) == -1)
168 err(1, "setsockopt MRT_ADD_VIF %s", ifaddr);
169
170 memset(&vif, 0, sizeof(vif));
171 vif.vifc_vifi = 1;
172 if (inet_pton(AF_INET, outaddr, &vif.vifc_lcl_addr) == -1)
173 err(1, "inet_pton %s", outaddr);
174 if (setsockopt(s, IPPROTO_IP, MRT_ADD_VIF, &vif, sizeof(vif)) == -1)
175 err(1, "setsockopt MRT_ADD_VIF %s", outaddr);
176
177 memset(&mfc, 0, sizeof(mfc));
178 if (inet_pton(AF_INET, group, &mfc.mfcc_mcastgrp) == -1)
179 err(1, "inet_pton %s", group);
180 mfc.mfcc_parent = 0;
181 mfc.mfcc_ttls[1] = 1;
182
183 if (setsockopt(s, IPPROTO_IP, MRT_ADD_MFC, &mfc, sizeof(mfc)) == -1)
184 err(1, "setsockopt MRT_ADD_MFC %s", group);
185
186 if (background) {
187 pid = fork();
188 switch (pid) {
189 case -1:
190 err(1, "fork");
191 case 0:
192 fd = open("/dev/null", O_RDWR);
193 if (fd == -1)
194 err(1, "open /dev/null");
195 if (dup2(fd, 0) == -1)
196 err(1, "dup 0");
197 if (dup2(fd, 1) == -1)
198 err(1, "dup 1");
199 if (dup2(fd, 2) == -1)
200 err(1, "dup 2");
201 break;
202 default:
203 _exit(0);
204 }
205 }
206
207 if (timeout) {
208 if (norecv) {
209 if (signal(SIGALRM, sigexit) == SIG_ERR)
210 err(1, "signal SIGALRM");
211 }
212 alarm(timeout);
213 }
214
215 buf = NULL;
216 pktin = pktout = 0;
217 do {
218 struct timespec sleeptime = { 0, 10000000 };
219
220 if (nanosleep(&sleeptime, NULL) == -1)
221 err(1, "nanosleep");
222 needed = get_sysctl(mib, sizeof(mib) / sizeof(mib[0]), &buf);
223 for (vinfo = (struct vifinfo *)buf;
224 (char *)vinfo < buf + needed;
225 vinfo++) {
226 switch (vinfo->v_vifi) {
227 case 0:
228 if (pktin != vinfo->v_pkt_in) {
229 fprintf(log, "<<< %lu\n",
230 vinfo->v_pkt_in);
231 fflush(log);
232 }
233 pktin = vinfo->v_pkt_in;
234 break;
235 case 1:
236 if (pktout != vinfo->v_pkt_out) {
237 fprintf(log, ">>> %lu\n",
238 vinfo->v_pkt_out);
239 fflush(log);
240 }
241 pktout = vinfo->v_pkt_out;
242 break;
243 }
244 }
245 } while (pktin == 0 || pktout == 0);
246 free(buf);
247
248 if (norecv)
249 errx(1, "pktin %lu, pktout %lu", pktin, pktout);
250
251 return 0;
252 }
253
254 void
sigexit(int sig)255 sigexit(int sig)
256 {
257 _exit(0);
258 }
259
260 /* from netstat(8) */
261 size_t
get_sysctl(const int * mib,u_int mcnt,char ** buf)262 get_sysctl(const int *mib, u_int mcnt, char **buf)
263 {
264 size_t needed;
265
266 while (1) {
267 if (sysctl(mib, mcnt, NULL, &needed, NULL, 0) == -1)
268 err(1, "sysctl-estimate");
269 if (needed == 0)
270 break;
271 if ((*buf = realloc(*buf, needed)) == NULL)
272 err(1, NULL);
273 if (sysctl(mib, mcnt, *buf, &needed, NULL, 0) == -1) {
274 if (errno == ENOMEM)
275 continue;
276 err(1, "sysctl");
277 }
278 break;
279 }
280
281 return needed;
282 }
283