ifwatchd.c revision 1.8
1 /* $NetBSD: ifwatchd.c,v 1.8 2002/04/15 20:42:37 tron Exp $ */ 2 3 /*- 4 * Copyright (c) 2002 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Martin Husemann <martin (at) NetBSD.ORG>. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 /* 40 * Define this for special treatment of sys/net/if_spppsubr.c based interfaces. 41 */ 42 #define SPPP_IF_SUPPORT 43 44 #include <sys/types.h> 45 #include <sys/param.h> 46 #include <sys/ioctl.h> 47 #include <sys/socket.h> 48 #include <sys/queue.h> 49 #include <net/if.h> 50 #include <net/if_dl.h> 51 #ifdef SPPP_IF_SUPPORT 52 #include <net/if_sppp.h> 53 #endif 54 #include <net/route.h> 55 #include <netinet/in.h> 56 #include <arpa/inet.h> 57 58 #include <paths.h> 59 #include <stdio.h> 60 #include <stdlib.h> 61 #include <string.h> 62 #include <unistd.h> 63 #include <netdb.h> 64 #include <err.h> 65 #include <ifaddrs.h> 66 67 /* local functions */ 68 static void usage(void); 69 static void dispatch(void*, size_t); 70 static void check_addrs(char *cp, int addrs, int is_up); 71 static void invoke_script(struct sockaddr *sa, struct sockaddr *dst, int is_up, int ifindex); 72 static void list_interfaces(const char *ifnames); 73 static void rescan_interfaces(void); 74 static void free_interfaces(void); 75 static int find_interface(int index); 76 static void run_initial_ups(void); 77 78 #ifdef SPPP_IF_SUPPORT 79 static int if_is_connected(const char * ifname); 80 #else 81 #define if_is_connected(X) 1 82 #endif 83 84 /* stolen from /sbin/route */ 85 #define ROUNDUP(a) \ 86 ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long)) 87 #define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len)) 88 89 /* global variables */ 90 static int verbose = 0; 91 static int inhibit_initial = 0; 92 static const char *up_script = NULL; 93 static const char *down_script = NULL; 94 95 struct interface_data { 96 SLIST_ENTRY(interface_data) next; 97 int index; 98 char * ifname; 99 }; 100 SLIST_HEAD(,interface_data) ifs = SLIST_HEAD_INITIALIZER(ifs); 101 102 int 103 main(int argc, char **argv) 104 { 105 int c, s, n; 106 int errs = 0; 107 char msg[2048], *msgp; 108 109 while ((c = getopt(argc, argv, "vhiu:d:")) != -1) 110 switch (c) { 111 case 'h': 112 usage(); 113 return 0; 114 case 'i': 115 inhibit_initial = 1; 116 break; 117 case 'v': 118 verbose++; 119 break; 120 121 case 'u': 122 up_script = optarg; 123 break; 124 125 case 'd': 126 down_script = optarg; 127 break; 128 129 default: 130 errs++; 131 break; 132 } 133 134 if (errs) 135 usage(); 136 137 argv += optind; 138 argc -= optind; 139 140 if (argc <= 0) 141 usage(); 142 143 if (verbose) { 144 printf("up_script: %s\ndown_script: %s\n", 145 up_script, down_script); 146 printf("verbosity = %d\n", verbose); 147 } 148 149 while (argc > 0) { 150 list_interfaces(argv[0]); 151 argv++; argc--; 152 } 153 154 if (!verbose) 155 daemon(0,0); 156 157 if (!inhibit_initial) 158 run_initial_ups(); 159 160 s = socket(PF_ROUTE, SOCK_RAW, 0); 161 if (s < 0) { 162 perror("open routing socket"); 163 exit(1); 164 } 165 166 for (;;) { 167 n = read(s, msg, sizeof msg); 168 msgp = msg; 169 for (msgp = msg; n > 0; n -= ((struct rt_msghdr*)msgp)->rtm_msglen, msgp += ((struct rt_msghdr*)msgp)->rtm_msglen) { 170 dispatch(msgp, n); 171 172 } 173 } 174 175 close(s); 176 free_interfaces(); 177 178 exit(0); 179 } 180 181 static void 182 usage() 183 { 184 fprintf(stderr, 185 "usage:\n" 186 "\tifwatchd [-h] [-v] [-u up-script] [-d down-script] ifname(s)\n" 187 "\twhere:\n" 188 "\t -h show this help message\n" 189 "\t -v verbose/debug output, don't run in background\n" 190 "\t -i no (!) initial run of the up script if the interface\n" 191 "\t is already up on ifwatchd startup\n" 192 "\t -u <cmd> specify command to run on interface up event\n" 193 "\t -d <cmd> specify command to run on interface down event\n"); 194 exit(1); 195 } 196 197 static void 198 dispatch(void *msg, size_t len) 199 { 200 struct rt_msghdr *hd = msg; 201 struct ifa_msghdr *ifam; 202 int is_up; 203 204 is_up = 0; 205 switch (hd->rtm_type) { 206 case RTM_NEWADDR: 207 is_up = 1; 208 goto work; 209 case RTM_DELADDR: 210 is_up = 0; 211 goto work; 212 case RTM_IFANNOUNCE: 213 rescan_interfaces(); 214 break; 215 } 216 if (verbose) 217 printf("unknown message ignored\n"); 218 return; 219 220 work: 221 ifam = (struct ifa_msghdr *)msg; 222 check_addrs((char *)(ifam + 1), ifam->ifam_addrs, is_up); 223 } 224 225 static void 226 check_addrs(cp, addrs, is_up) 227 char *cp; 228 int addrs, is_up; 229 { 230 struct sockaddr *sa, *ifa = NULL, *brd = NULL; 231 int ifndx = 0, i; 232 233 if (addrs == 0) 234 return; 235 for (i = 1; i; i <<= 1) { 236 if (i & addrs) { 237 sa = (struct sockaddr *)cp; 238 if (i == RTA_IFP) { 239 struct sockaddr_dl * li = (struct sockaddr_dl*)sa; 240 ifndx = li->sdl_index; 241 if (!find_interface(ifndx)) { 242 if (verbose) 243 printf("ignoring change on interface #%d\n", ifndx); 244 return; 245 } 246 } else if (i == RTA_IFA) { 247 ifa = sa; 248 } else if (i == RTA_BRD) { 249 brd = sa; 250 } 251 ADVANCE(cp, sa); 252 } 253 } 254 if (ifa != NULL) 255 invoke_script(ifa, brd, is_up, ifndx); 256 } 257 258 static void 259 invoke_script(sa, dest, is_up, ifindex) 260 struct sockaddr *sa, *dest; 261 int is_up, ifindex; 262 { 263 char addr[NI_MAXHOST], daddr[NI_MAXHOST], ifname_buf[IFNAMSIZ], 264 *ifname, *cmd; 265 const char *script; 266 267 if (sa->sa_family == AF_INET6) { 268 struct sockaddr_in6 sin6; 269 270 (void) memcpy(&sin6, (struct sockaddr_in6 *)sa, sizeof (sin6)); 271 if (IN6_IS_ADDR_LINKLOCAL(&sin6.sin6_addr)) 272 return; 273 } 274 275 daddr[0] = 0; 276 ifname = if_indextoname(ifindex, ifname_buf); 277 if (sa->sa_len == 0) { 278 fprintf(stderr, "illegal socket address (sa_len == 0)\n"); 279 return; 280 } 281 282 if (getnameinfo(sa, sa->sa_len, addr, sizeof addr, NULL, 0, NI_NUMERICHOST)) { 283 if (verbose) 284 printf("getnameinfo failed\n"); 285 return; /* this address can not be handled */ 286 } 287 if (dest != NULL) { 288 if (getnameinfo(dest, dest->sa_len, daddr, sizeof daddr, NULL, 0, NI_NUMERICHOST)) { 289 if (verbose) 290 printf("getnameinfo failed\n"); 291 return; /* this address can not be handled */ 292 } 293 } 294 295 script = is_up? up_script : down_script; 296 if (script == NULL) return; 297 298 asprintf(&cmd, "%s \"%s\" " _PATH_DEVNULL " 9600 \"%s\" \"%s\"", 299 script, ifname, addr, daddr); 300 if (cmd == NULL) { 301 fprintf(stderr, "out of memory\n"); 302 return; 303 } 304 if (verbose) 305 printf("calling: %s\n", cmd); 306 system(cmd); 307 free(cmd); 308 } 309 310 static void list_interfaces(const char *ifnames) 311 { 312 char * names = strdup(ifnames); 313 char * name, *lasts; 314 static const char sep[] = " \t"; 315 struct interface_data * p; 316 317 for (name = strtok_r(names, sep, &lasts); name != NULL; name = strtok_r(NULL, sep, &lasts)) { 318 p = malloc(sizeof(*p)); 319 SLIST_INSERT_HEAD(&ifs, p, next); 320 p->ifname = strdup(name); 321 p->index = if_nametoindex(p->ifname); 322 if (verbose) 323 printf("interface \"%s\" has index %d\n", p->ifname, p->index); 324 } 325 free(names); 326 } 327 328 static void rescan_interfaces() 329 { 330 struct interface_data * p; 331 332 SLIST_FOREACH(p, &ifs, next) { 333 p->index = if_nametoindex(p->ifname); 334 if (verbose) 335 printf("interface \"%s\" has index %d\n", p->ifname, p->index); 336 } 337 } 338 339 static void free_interfaces() 340 { 341 struct interface_data * p; 342 343 while (!SLIST_EMPTY(&ifs)) { 344 p = SLIST_FIRST(&ifs); 345 SLIST_REMOVE_HEAD(&ifs, next); 346 free(p->ifname); 347 free(p); 348 } 349 } 350 351 static int find_interface(index) 352 int index; 353 { 354 struct interface_data * p; 355 356 SLIST_FOREACH(p, &ifs, next) 357 if (p->index == index) 358 return 1; 359 return 0; 360 } 361 362 static void run_initial_ups() 363 { 364 struct interface_data * ifd; 365 struct ifaddrs *res = NULL, *p; 366 367 if (getifaddrs(&res) == 0) { 368 for (p = res; p; p = p->ifa_next) { 369 if ((p->ifa_flags & IFF_UP) == 0) 370 continue; 371 if (p->ifa_addr == NULL) 372 continue; 373 if (p->ifa_addr->sa_family == AF_LINK) 374 continue; 375 SLIST_FOREACH(ifd, &ifs, next) { 376 if (strcmp(ifd->ifname, p->ifa_name) == 0) { 377 if (if_is_connected(ifd->ifname)) 378 invoke_script(p->ifa_addr, p->ifa_dstaddr, 1, ifd->index); 379 break; 380 } 381 } 382 } 383 freeifaddrs(res); 384 } 385 } 386 387 #ifdef SPPP_IF_SUPPORT 388 /* 389 * Special case support for in-kernel PPP interfaces. 390 * If these are IFF_UP, but have not yet connected or completed authentication 391 * we don't want to call the up script in the initial interface scan (there 392 * will be an UP event generated later, when IPCP completes, anyway). 393 * 394 * If this is no if_spppsubr.c based interface, this ioctl just fails and we 395 * treat is as connected. 396 */ 397 static int 398 if_is_connected(const char * ifname) 399 { 400 int s, err; 401 struct spppstatus status; 402 403 memset(&status, 0, sizeof status); 404 strncpy(status.ifname, ifname, sizeof status.ifname); 405 s = socket(AF_INET, SOCK_DGRAM, 0); 406 if (s < 0) 407 return 1; /* no idea how to handle this... */ 408 err = ioctl(s, SPPPGETSTATUS, &status); 409 if (err != 0) 410 /* not if_spppsubr.c based - call it connected */ 411 status.phase = SPPP_PHASE_NETWORK; 412 close(s); 413 return status.phase == SPPP_PHASE_NETWORK; 414 } 415 #endif 416
Indexes created Sun Sep 28 16:09:52 GMT 2025