Commit | Line | Data |
---|---|---|
3415540f FT |
1 | #include <stdlib.h> |
2 | #include <stdio.h> | |
3 | #include <string.h> | |
4 | #include <unistd.h> | |
5 | #include <sys/socket.h> | |
6 | #include <netinet/in.h> | |
b5038e15 FT |
7 | #include <arpa/inet.h> |
8 | #include <errno.h> | |
49697920 FT |
9 | #include <net/if.h> |
10 | #include <linux/if_tun.h> | |
11 | #include <fcntl.h> | |
12 | #include <sys/ioctl.h> | |
13 | #include <sys/poll.h> | |
a13b233b | 14 | #include <syslog.h> |
1fefa40d | 15 | #include <signal.h> |
b5038e15 FT |
16 | |
17 | #include "utils.h" | |
3415540f | 18 | |
1fefa40d FT |
19 | static int quit = 0; |
20 | ||
3415540f FT |
21 | static void usage(FILE *out) |
22 | { | |
1fefa40d | 23 | fprintf(out, "usage: mctap [-hdp] [-P PIDFILE] [-D TAPNAME] MCASTGROUP PORT\n"); |
b5038e15 FT |
24 | } |
25 | ||
49697920 | 26 | static __attribute__ ((unused)) char *formataddress(struct sockaddr *arg, socklen_t arglen) |
b5038e15 FT |
27 | { |
28 | struct sockaddr_in *ipv4; | |
29 | struct sockaddr_in6 *ipv6; | |
30 | static char *ret = NULL; | |
31 | char buf[1024]; | |
32 | ||
33 | if(ret != NULL) | |
34 | free(ret); | |
35 | ret = NULL; | |
36 | switch(arg->sa_family) | |
37 | { | |
38 | case AF_UNIX: | |
49697920 | 39 | ret = sstrdup("Unix socket"); |
b5038e15 FT |
40 | break; |
41 | case AF_INET: | |
42 | ipv4 = (struct sockaddr_in *)arg; | |
43 | if(inet_ntop(AF_INET, &ipv4->sin_addr, buf, sizeof(buf)) == NULL) | |
44 | return(NULL); | |
45 | ret = sprintf2("%s:%i", buf, (int)ntohs(ipv4->sin_port)); | |
46 | break; | |
47 | case AF_INET6: | |
48 | ipv6 = (struct sockaddr_in6 *)arg; | |
49 | if(inet_ntop(AF_INET6, &ipv6->sin6_addr, buf, sizeof(buf)) == NULL) | |
50 | return(NULL); | |
51 | ret = sprintf2("[%s]:%i", buf, (int)ntohs(ipv6->sin6_port)); | |
52 | break; | |
53 | default: | |
54 | errno = EPFNOSUPPORT; | |
55 | break; | |
56 | } | |
57 | return(ret); | |
58 | } | |
59 | ||
60 | static int mkmcastsk4(struct in_addr group, int port) | |
61 | { | |
62 | int fd; | |
aeddd223 | 63 | int soval; |
b5038e15 FT |
64 | struct sockaddr_in nm; |
65 | struct ip_mreqn mreq; | |
66 | ||
67 | fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP); | |
aeddd223 FT |
68 | soval = 1; |
69 | if(setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &soval, sizeof(soval))) | |
70 | return(-1); | |
b5038e15 FT |
71 | memset(&nm, 0, sizeof(nm)); |
72 | nm.sin_family = AF_INET; | |
73 | nm.sin_port = htons(port); | |
74 | if(bind(fd, (struct sockaddr *)&nm, sizeof(nm))) | |
75 | return(-1); | |
76 | memset(&mreq, 0, sizeof(mreq)); | |
77 | mreq.imr_multiaddr = group; | |
aeddd223 | 78 | if(setsockopt(fd, SOL_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq))) |
b5038e15 | 79 | return(-1); |
af3fc4a5 FT |
80 | soval = 1; |
81 | if(setsockopt(fd, SOL_IP, IP_MULTICAST_LOOP, &soval, sizeof(soval))) | |
82 | return(-1); | |
b5038e15 FT |
83 | return(fd); |
84 | } | |
85 | ||
49697920 | 86 | static __attribute__ ((unused)) void test(int fd) |
b5038e15 FT |
87 | { |
88 | char buf[65536]; | |
4f6c7408 | 89 | int i, ret; |
49697920 | 90 | struct pollfd pfd; |
b5038e15 FT |
91 | |
92 | while(1) { | |
49697920 FT |
93 | pfd.fd = fd; |
94 | pfd.events = POLLIN; | |
95 | ret = poll(&pfd, 1, -1); | |
b5038e15 | 96 | if(ret < 0) { |
49697920 | 97 | fprintf(stderr, "mctap: poll: %s\n", strerror(errno)); |
b5038e15 FT |
98 | exit(1); |
99 | } | |
49697920 FT |
100 | if(pfd.revents) { |
101 | ret = read(fd, buf, sizeof(buf)); | |
102 | if(ret < 0) { | |
103 | fprintf(stderr, "mctap: read: %s\n", strerror(errno)); | |
104 | exit(1); | |
105 | } | |
106 | for(i = 0; i < ret; i++) { | |
107 | printf("%02x ", (unsigned char)buf[i]); | |
108 | if(i % 20 == 19) | |
109 | putchar(10); | |
110 | } | |
111 | putchar(10); | |
4f6c7408 | 112 | } |
b5038e15 | 113 | } |
3415540f FT |
114 | } |
115 | ||
49697920 FT |
116 | static void bridge(int sock, int tap, struct sockaddr *dst, socklen_t dstlen) |
117 | { | |
118 | char buf[65536]; | |
119 | int ret; | |
120 | struct pollfd pfds[2]; | |
121 | struct tun_pi pi; | |
122 | ||
123 | fcntl(sock, F_SETFL, fcntl(sock, F_GETFL) | O_NONBLOCK); | |
124 | fcntl(tap, F_SETFL, fcntl(tap, F_GETFL) | O_NONBLOCK); | |
1fefa40d | 125 | while(!quit) { |
49697920 FT |
126 | pfds[0].fd = sock; |
127 | pfds[0].events = POLLIN; | |
128 | pfds[1].fd = tap; | |
129 | pfds[1].events = POLLIN; | |
130 | ret = poll(pfds, 2, -1); | |
131 | if(ret < 0) { | |
132 | if(errno != EINTR) { | |
a13b233b | 133 | syslog(LOG_ERR, "mctap: poll: %s", strerror(errno)); |
49697920 FT |
134 | exit(1); |
135 | } | |
136 | continue; | |
137 | } | |
138 | if(pfds[0].revents) { | |
139 | ret = read(sock, buf, sizeof(buf)); | |
140 | if(ret < 0) { | |
141 | if((errno != EINTR) && (errno != EAGAIN)) { | |
a13b233b | 142 | syslog(LOG_ERR, "mctap: mcast packet: %s", strerror(errno)); |
49697920 FT |
143 | exit(1); |
144 | } | |
145 | } else { | |
146 | if(sizeof(buf) - ret < sizeof(pi)) { | |
147 | /* Drop */ | |
148 | } else { | |
149 | memmove(buf + sizeof(pi), buf, ret); | |
150 | pi.flags = 0; | |
151 | pi.proto = 0; | |
152 | memcpy(buf, &pi, sizeof(pi)); | |
3cb771e8 | 153 | write(tap, buf, sizeof(pi) + ret); |
49697920 FT |
154 | } |
155 | } | |
156 | } | |
157 | if(pfds[1].revents) { | |
158 | ret = read(tap, buf, sizeof(buf)); | |
159 | if(ret < 0) { | |
160 | if((errno != EINTR) && (errno != EAGAIN)) { | |
a13b233b | 161 | syslog(LOG_ERR, "mctap: mcast packet: %s", strerror(errno)); |
49697920 FT |
162 | exit(1); |
163 | } | |
164 | } else { | |
165 | if(ret < sizeof(pi)) { | |
166 | /* Drop */ | |
167 | } else { | |
168 | memcpy(&pi, buf, sizeof(pi)); | |
169 | if(pi.flags & TUN_PKT_STRIP) { | |
170 | /* Drop */ | |
171 | } else { | |
172 | sendto(sock, buf + sizeof(pi), ret - sizeof(pi), 0, dst, dstlen); | |
173 | } | |
174 | } | |
175 | } | |
176 | } | |
177 | } | |
178 | } | |
179 | ||
180 | static int maketap(char *name) | |
181 | { | |
182 | int fd; | |
183 | struct ifreq rb; | |
184 | ||
185 | if((fd = open("/dev/net/tun", O_RDWR)) < 0) | |
186 | return(-1); | |
187 | memset(&rb, 0, sizeof(rb)); | |
188 | rb.ifr_flags = IFF_TAP; | |
189 | strncpy(rb.ifr_name, name, IFNAMSIZ); | |
190 | if(ioctl(fd, TUNSETIFF, &rb)) | |
191 | return(-1); | |
192 | return(fd); | |
193 | } | |
194 | ||
1fefa40d FT |
195 | static void sighand(int sig) |
196 | { | |
197 | switch(sig) { | |
198 | case SIGINT: | |
199 | case SIGTERM: | |
200 | quit = 1; | |
201 | break; | |
202 | case SIGHUP: | |
203 | break; | |
204 | } | |
205 | } | |
206 | ||
3415540f FT |
207 | int main(int argc, char **argv) |
208 | { | |
209 | int c; | |
49697920 | 210 | int sock, tap; |
b5038e15 FT |
211 | struct in_addr group; |
212 | int port; | |
49697920 | 213 | char *tapname; |
1fefa40d | 214 | char *pidfile; |
a13b233b | 215 | int daemonize; |
49697920 | 216 | struct sockaddr_in dst; |
1fefa40d | 217 | FILE *pidfd; |
3415540f | 218 | |
49697920 | 219 | tapname = "mctap"; |
a13b233b | 220 | daemonize = 0; |
1fefa40d FT |
221 | pidfile = NULL; |
222 | while((c = getopt(argc, argv, "hD:dpP:")) >= 0) { | |
3415540f | 223 | switch(c) { |
49697920 FT |
224 | case 'D': |
225 | tapname = optarg; | |
226 | break; | |
a13b233b FT |
227 | case 'd': |
228 | daemonize = 1; | |
229 | break; | |
1fefa40d FT |
230 | case 'p': |
231 | pidfile = (void *)-1; | |
232 | break; | |
233 | case 'P': | |
234 | pidfile = optarg; | |
235 | break; | |
3415540f FT |
236 | case 'h': |
237 | usage(stdout); | |
238 | return(0); | |
239 | default: | |
240 | usage(stderr); | |
241 | exit(1); | |
242 | } | |
243 | } | |
1fefa40d FT |
244 | if(pidfile == (void *)-1) |
245 | pidfile = sprintf2("/var/run/mctap.%s.pid", tapname); | |
b5038e15 FT |
246 | if(argc - optind < 2) { |
247 | usage(stderr); | |
248 | exit(1); | |
249 | } | |
250 | if(!inet_aton(argv[optind], &group)) { | |
251 | fprintf(stderr, "mctap: invalid group address: %s\n", argv[optind]); | |
252 | exit(1); | |
253 | } | |
254 | port = atoi(argv[optind + 1]); | |
255 | if((sock = mkmcastsk4(group, port)) < 0) { | |
256 | fprintf(stderr, "mctap: could not create multicast socket: %s\n", strerror(errno)); | |
257 | exit(1); | |
258 | } | |
49697920 FT |
259 | if((tap = maketap(tapname)) < 0) { |
260 | fprintf(stderr, "mctap: could not create TAP device: %s\n", strerror(errno)); | |
261 | exit(1); | |
262 | } | |
a13b233b FT |
263 | openlog(sprintf2("mctap-%s", tapname), LOG_PID, LOG_DAEMON); |
264 | ||
1fefa40d FT |
265 | pidfd = NULL; |
266 | if((pidfile != NULL) && ((pidfd = fopen(pidfile, "w")) == NULL)) { | |
267 | fprintf(stderr, "mctap: could not create PID file %s: %s\n", pidfile, strerror(errno)); | |
268 | exit(1); | |
269 | } | |
a13b233b FT |
270 | if(daemonize) |
271 | daemon(0, 0); | |
1fefa40d FT |
272 | if(pidfd != NULL) { |
273 | fprintf(pidfd, "%i\n", getpid()); | |
274 | fclose(pidfd); | |
275 | } | |
276 | ||
277 | signal(SIGTERM, sighand); | |
278 | signal(SIGINT, sighand); | |
279 | signal(SIGHUP, sighand); | |
3415540f | 280 | |
49697920 FT |
281 | memset(&dst, 0, sizeof(dst)); |
282 | dst.sin_family = AF_INET; | |
283 | dst.sin_addr = group; | |
284 | dst.sin_port = htons(port); | |
285 | bridge(sock, tap, (struct sockaddr *)&dst, sizeof(dst)); | |
1fefa40d FT |
286 | syslog(LOG_INFO, "exiting"); |
287 | ||
288 | if(pidfile != NULL) | |
289 | unlink(pidfile); | |
3415540f FT |
290 | return(0); |
291 | } |