arp.c revision 1.23.10.2
1 /* $NetBSD: arp.c,v 1.23.10.2 2001/05/01 12:43:30 he Exp $ */ 2 3 /* 4 * Copyright (c) 1984, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Sun Microsystems, Inc. 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 University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #ifndef lint 41 __COPYRIGHT("@(#) Copyright (c) 1984, 1993\n\ 42 The Regents of the University of California. All rights reserved.\n"); 43 #endif /* not lint */ 44 45 #ifndef lint 46 #if 0 47 static char sccsid[] = "@(#)arp.c 8.3 (Berkeley) 4/28/95"; 48 #else 49 __RCSID("$NetBSD: arp.c,v 1.23.10.2 2001/05/01 12:43:30 he Exp $"); 50 #endif 51 #endif /* not lint */ 52 53 /* 54 * arp - display, set, and delete arp table entries 55 */ 56 57 #include <sys/param.h> 58 #include <sys/file.h> 59 #include <sys/socket.h> 60 #include <sys/sysctl.h> 61 62 #include <net/if.h> 63 #include <net/if_dl.h> 64 #include <net/if_ether.h> 65 #include <net/if_types.h> 66 #include <net/route.h> 67 #include <netinet/in.h> 68 #include <netinet/if_inarp.h> 69 #include <arpa/inet.h> 70 71 #include <err.h> 72 #include <errno.h> 73 #include <netdb.h> 74 #include <nlist.h> 75 #include <paths.h> 76 #include <stdio.h> 77 #include <stdlib.h> 78 #include <string.h> 79 #include <unistd.h> 80 81 int delete __P((const char *, const char *)); 82 void dump __P((u_long)); 83 void delete_all __P((void)); 84 void sdl_print __P((const struct sockaddr_dl *)); 85 int atosdl __P((const char *s, struct sockaddr_dl *sdl)); 86 int file __P((char *)); 87 void get __P((const char *)); 88 int getinetaddr __P((const char *, struct in_addr *)); 89 void getsocket __P((void)); 90 int main __P((int, char **)); 91 int rtmsg __P((int)); 92 int set __P((int, char **)); 93 void usage __P((void)); 94 95 static int pid; 96 static int aflag, nflag, vflag; 97 static int s = -1; 98 99 int delete __P((const char *, const char *)); 100 void dump __P((u_long)); 101 void ether_print __P((const u_char *)); 102 int file __P((char *)); 103 void get __P((const char *)); 104 int getinetaddr __P((const char *, struct in_addr *)); 105 void getsocket __P((void)); 106 int rtmsg __P((int)); 107 int set __P((int, char **)); 108 void usage __P((void)); 109 110 int 111 main(argc, argv) 112 int argc; 113 char **argv; 114 { 115 int ch; 116 int op = 0; 117 118 pid = getpid(); 119 120 while ((ch = getopt(argc, argv, "andsfv")) != -1) 121 switch((char)ch) { 122 case 'a': 123 aflag = 1; 124 break; 125 case 'd': 126 case 's': 127 case 'f': 128 if (op) 129 usage(); 130 op = ch; 131 break; 132 case 'n': 133 nflag = 1; 134 break; 135 case 'v': 136 vflag = 1; 137 break; 138 default: 139 usage(); 140 } 141 argc -= optind; 142 argv += optind; 143 144 if (!op && aflag) 145 op = 'a'; 146 147 switch((char)op) { 148 case 'a': 149 dump(0); 150 break; 151 case 'd': 152 if (aflag && argc == 0) 153 delete_all(); 154 else { 155 if (aflag || argc < 1 || argc > 2) 156 usage(); 157 (void)delete(argv[0], argv[1]); 158 } 159 break; 160 case 's': 161 if (argc < 2 || argc > 5) 162 usage(); 163 return (set(argc, argv) ? 1 : 0); 164 case 'f': 165 if (argc != 1) 166 usage(); 167 return (file(argv[0])); 168 default: 169 if (argc != 1) 170 usage(); 171 get(argv[0]); 172 break; 173 } 174 return (0); 175 } 176 177 /* 178 * Process a file to set standard arp entries 179 */ 180 int 181 file(name) 182 char *name; 183 { 184 char line[100], arg[5][50], *args[5]; 185 int i, retval; 186 FILE *fp; 187 188 if ((fp = fopen(name, "r")) == NULL) 189 err(1, "cannot open %s", name); 190 args[0] = &arg[0][0]; 191 args[1] = &arg[1][0]; 192 args[2] = &arg[2][0]; 193 args[3] = &arg[3][0]; 194 args[4] = &arg[4][0]; 195 retval = 0; 196 while (fgets(line, 100, fp) != NULL) { 197 i = sscanf(line, "%s %s %s %s %s", arg[0], arg[1], arg[2], 198 arg[3], arg[4]); 199 if (i < 2) { 200 warnx("bad line: %s", line); 201 retval = 1; 202 continue; 203 } 204 if (set(i, args)) 205 retval = 1; 206 } 207 fclose(fp); 208 return (retval); 209 } 210 211 void 212 getsocket() 213 { 214 if (s >= 0) 215 return; 216 s = socket(PF_ROUTE, SOCK_RAW, 0); 217 if (s < 0) 218 err(1, "socket"); 219 } 220 221 struct sockaddr_in so_mask = {8, 0, 0, { 0xffffffff}}; 222 struct sockaddr_inarp blank_sin = {sizeof(blank_sin), AF_INET }, sin_m; 223 struct sockaddr_dl blank_sdl = {sizeof(blank_sdl), AF_LINK }, sdl_m; 224 int expire_time, flags, export_only, doing_proxy, found_entry; 225 struct { 226 struct rt_msghdr m_rtm; 227 char m_space[512]; 228 } m_rtmsg; 229 230 /* 231 * Set an individual arp entry 232 */ 233 int 234 set(argc, argv) 235 int argc; 236 char **argv; 237 { 238 struct sockaddr_inarp *sin; 239 struct sockaddr_dl *sdl; 240 struct rt_msghdr *rtm; 241 char *host = argv[0], *eaddr; 242 int rval; 243 244 sin = &sin_m; 245 rtm = &(m_rtmsg.m_rtm); 246 eaddr = argv[1]; 247 248 getsocket(); 249 argc -= 2; 250 argv += 2; 251 sdl_m = blank_sdl; /* struct copy */ 252 sin_m = blank_sin; /* struct copy */ 253 if (getinetaddr(host, &sin->sin_addr) == -1) 254 return (1); 255 if (atosdl(eaddr, &sdl_m)) 256 warnx("invalid link-level address '%s'", eaddr); 257 doing_proxy = flags = export_only = expire_time = 0; 258 while (argc-- > 0) { 259 if (strncmp(argv[0], "temp", 4) == 0) { 260 struct timeval time; 261 (void)gettimeofday(&time, 0); 262 expire_time = time.tv_sec + 20 * 60; 263 } 264 else if (strncmp(argv[0], "pub", 3) == 0) { 265 flags |= RTF_ANNOUNCE; 266 doing_proxy = SIN_PROXY; 267 } else if (strncmp(argv[0], "trail", 5) == 0) { 268 (void)printf( 269 "%s: Sending trailers is no longer supported\n", 270 host); 271 } 272 argv++; 273 } 274 tryagain: 275 if (rtmsg(RTM_GET) < 0) { 276 warn("%s", host); 277 return (1); 278 } 279 sin = (struct sockaddr_inarp *)(rtm + 1); 280 sdl = (struct sockaddr_dl *)(sin->sin_len + (char *)sin); 281 if (sin->sin_addr.s_addr == sin_m.sin_addr.s_addr) { 282 if (sdl->sdl_family == AF_LINK && 283 (rtm->rtm_flags & RTF_LLINFO) && 284 !(rtm->rtm_flags & RTF_GATEWAY)) switch (sdl->sdl_type) { 285 case IFT_ETHER: case IFT_FDDI: case IFT_ISO88023: 286 case IFT_ISO88024: case IFT_ISO88025: case IFT_ARCNET: 287 goto overwrite; 288 } 289 if (doing_proxy == 0) { 290 (void)printf("set: can only proxy for %s\n", host); 291 return (1); 292 } 293 if (sin_m.sin_other & SIN_PROXY) { 294 (void)printf( 295 "set: proxy entry exists for non 802 device\n"); 296 return (1); 297 } 298 sin_m.sin_other = SIN_PROXY; 299 export_only = 1; 300 goto tryagain; 301 } 302 overwrite: 303 if (sdl->sdl_family != AF_LINK) { 304 (void)printf("cannot intuit interface index and type for %s\n", 305 host); 306 return (1); 307 } 308 sdl_m.sdl_type = sdl->sdl_type; 309 sdl_m.sdl_index = sdl->sdl_index; 310 rval = rtmsg(RTM_ADD); 311 if (vflag) 312 (void)printf("%s (%s) added\n", host, eaddr); 313 return (rval); 314 } 315 316 /* 317 * Display an individual arp entry 318 */ 319 void 320 get(host) 321 const char *host; 322 { 323 struct sockaddr_inarp *sin; 324 325 sin = &sin_m; 326 sin_m = blank_sin; /* struct copy */ 327 if (getinetaddr(host, &sin->sin_addr) == -1) 328 exit(1); 329 dump(sin->sin_addr.s_addr); 330 if (found_entry == 0) { 331 (void)printf("%s (%s) -- no entry\n", host, 332 inet_ntoa(sin->sin_addr)); 333 exit(1); 334 } 335 } 336 337 /* 338 * Delete an arp entry 339 */ 340 int 341 delete(host, info) 342 const char *host; 343 const char *info; 344 { 345 struct sockaddr_inarp *sin; 346 struct rt_msghdr *rtm; 347 struct sockaddr_dl *sdl; 348 349 sin = &sin_m; 350 rtm = &m_rtmsg.m_rtm; 351 352 if (info && strncmp(info, "pro", 3) ) 353 export_only = 1; 354 getsocket(); 355 sin_m = blank_sin; /* struct copy */ 356 if (getinetaddr(host, &sin->sin_addr) == -1) 357 return (1); 358 tryagain: 359 if (rtmsg(RTM_GET) < 0) { 360 warn("%s", host); 361 return (1); 362 } 363 sin = (struct sockaddr_inarp *)(rtm + 1); 364 sdl = (struct sockaddr_dl *)(sin->sin_len + (char *)sin); 365 if (sin->sin_addr.s_addr == sin_m.sin_addr.s_addr) { 366 if (sdl->sdl_family == AF_LINK && 367 (rtm->rtm_flags & RTF_LLINFO) && 368 !(rtm->rtm_flags & RTF_GATEWAY)) switch (sdl->sdl_type) { 369 case IFT_ETHER: case IFT_FDDI: case IFT_ISO88023: 370 case IFT_ISO88024: case IFT_ISO88025: case IFT_ARCNET: 371 goto delete; 372 } 373 } 374 if (sin_m.sin_other & SIN_PROXY) { 375 warnx("delete: can't locate %s", host); 376 return (1); 377 } else { 378 sin_m.sin_other = SIN_PROXY; 379 goto tryagain; 380 } 381 delete: 382 if (sdl->sdl_family != AF_LINK) { 383 (void)printf("cannot locate %s\n", host); 384 return (1); 385 } 386 if (rtmsg(RTM_DELETE)) 387 return (1); 388 if (vflag) 389 (void)printf("%s (%s) deleted\n", host, 390 inet_ntoa(sin->sin_addr)); 391 return (0); 392 } 393 394 /* 395 * Dump the entire arp table 396 */ 397 void 398 dump(addr) 399 u_long addr; 400 { 401 int mib[6]; 402 size_t needed; 403 char *host, *lim, *buf, *next; 404 struct rt_msghdr *rtm; 405 struct sockaddr_inarp *sin; 406 struct sockaddr_dl *sdl; 407 extern int h_errno; 408 struct hostent *hp; 409 410 mib[0] = CTL_NET; 411 mib[1] = PF_ROUTE; 412 mib[2] = 0; 413 mib[3] = AF_INET; 414 mib[4] = NET_RT_FLAGS; 415 mib[5] = RTF_LLINFO; 416 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) 417 err(1, "route-sysctl-estimate"); 418 if (needed == 0) 419 return; 420 if ((buf = malloc(needed)) == NULL) 421 err(1, "malloc"); 422 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) 423 err(1, "actual retrieval of routing table"); 424 lim = buf + needed; 425 for (next = buf; next < lim; next += rtm->rtm_msglen) { 426 rtm = (struct rt_msghdr *)next; 427 sin = (struct sockaddr_inarp *)(rtm + 1); 428 sdl = (struct sockaddr_dl *)(sin + 1); 429 if (addr) { 430 if (addr != sin->sin_addr.s_addr) 431 continue; 432 found_entry = 1; 433 } 434 if (nflag == 0) 435 hp = gethostbyaddr((caddr_t)&(sin->sin_addr), 436 sizeof sin->sin_addr, AF_INET); 437 else 438 hp = 0; 439 if (hp) 440 host = hp->h_name; 441 else { 442 host = "?"; 443 if (h_errno == TRY_AGAIN) 444 nflag = 1; 445 } 446 (void)printf("%s (%s) at ", host, inet_ntoa(sin->sin_addr)); 447 if (sdl->sdl_alen) 448 sdl_print(sdl); 449 else 450 (void)printf("(incomplete)"); 451 if (rtm->rtm_rmx.rmx_expire == 0) 452 (void)printf(" permanent"); 453 if (sin->sin_other & SIN_PROXY) 454 (void)printf(" published (proxy only)"); 455 if (rtm->rtm_addrs & RTA_NETMASK) { 456 sin = (struct sockaddr_inarp *) 457 (sdl->sdl_len + (char *)sdl); 458 if (sin->sin_addr.s_addr == 0xffffffff) 459 (void)printf(" published"); 460 if (sin->sin_len != 8) 461 (void)printf("(wierd)"); 462 } 463 (void)printf("\n"); 464 } 465 } 466 467 /* 468 * Delete the entire arp table 469 */ 470 void 471 delete_all(void) 472 { 473 int mib[6]; 474 size_t needed; 475 char addr[sizeof("000.000.000.000\0")]; 476 char *lim, *buf, *next; 477 struct rt_msghdr *rtm; 478 struct sockaddr_inarp *sin; 479 struct sockaddr_dl *sdl; 480 481 mib[0] = CTL_NET; 482 mib[1] = PF_ROUTE; 483 mib[2] = 0; 484 mib[3] = AF_INET; 485 mib[4] = NET_RT_FLAGS; 486 mib[5] = RTF_LLINFO; 487 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) 488 err(1, "route-sysctl-estimate"); 489 if (needed == 0) 490 return; 491 if ((buf = malloc(needed)) == NULL) 492 err(1, "malloc"); 493 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) 494 err(1, "actual retrieval of routing table"); 495 lim = buf + needed; 496 for (next = buf; next < lim; next += rtm->rtm_msglen) { 497 rtm = (struct rt_msghdr *)next; 498 sin = (struct sockaddr_inarp *)(rtm + 1); 499 sdl = (struct sockaddr_dl *)(sin + 1); 500 snprintf(addr, sizeof(addr), "%s", inet_ntoa(sin->sin_addr)); 501 delete(addr, NULL); 502 } 503 } 504 505 void 506 sdl_print(sdl) 507 const struct sockaddr_dl *sdl; 508 { 509 int i; 510 u_int8_t *p; 511 512 i = sdl->sdl_alen; 513 p = LLADDR(sdl); 514 515 (void)printf("%02x", *p); 516 while (--i > 0) { 517 putchar(':'); 518 (void)printf("%02x", *++p); 519 } 520 } 521 522 int 523 atosdl(s, sdl) 524 const char *s; 525 struct sockaddr_dl *sdl; 526 { 527 int i; 528 long b; 529 caddr_t endp; 530 caddr_t p; 531 char *t, *r; 532 533 p = LLADDR(sdl); 534 endp = ((caddr_t)sdl) + sdl->sdl_len; 535 i = 0; 536 537 b = strtol(s, &t, 16); 538 if (t == s) 539 return 1; 540 541 *p++ = b; 542 ++i; 543 while ((p < endp) && (*t++ == ':')) { 544 b = strtol(t, &r, 16); 545 if (r == t) 546 break; 547 *p++ = b; 548 ++i; 549 t = r; 550 } 551 sdl->sdl_alen = i; 552 553 return 0; 554 } 555 556 void 557 usage() 558 { 559 extern char *__progname; 560 561 (void)fprintf(stderr, "usage: %s [-n] hostname\n", __progname); 562 (void)fprintf(stderr, "usage: %s [-n] -a\n", __progname); 563 (void)fprintf(stderr, "usage: %s -d [-a|hostname]\n", __progname); 564 (void)fprintf(stderr, 565 "usage: %s -s hostname ether_addr [temp] [pub]\n", __progname); 566 (void)fprintf(stderr, "usage: %s -f filename\n", __progname); 567 exit(1); 568 } 569 570 int 571 rtmsg(cmd) 572 int cmd; 573 { 574 static int seq; 575 int rlen; 576 struct rt_msghdr *rtm; 577 char *cp; 578 int l; 579 580 rtm = &m_rtmsg.m_rtm; 581 cp = m_rtmsg.m_space; 582 errno = 0; 583 584 if (cmd == RTM_DELETE) 585 goto doit; 586 (void)memset(&m_rtmsg, 0, sizeof(m_rtmsg)); 587 rtm->rtm_flags = flags; 588 rtm->rtm_version = RTM_VERSION; 589 590 switch (cmd) { 591 default: 592 errx(1, "internal wrong cmd"); 593 /*NOTREACHED*/ 594 case RTM_ADD: 595 rtm->rtm_addrs |= RTA_GATEWAY; 596 rtm->rtm_rmx.rmx_expire = expire_time; 597 rtm->rtm_inits = RTV_EXPIRE; 598 rtm->rtm_flags |= (RTF_HOST | RTF_STATIC); 599 sin_m.sin_other = 0; 600 if (doing_proxy) { 601 if (export_only) 602 sin_m.sin_other = SIN_PROXY; 603 else { 604 rtm->rtm_addrs |= RTA_NETMASK; 605 rtm->rtm_flags &= ~RTF_HOST; 606 } 607 } 608 /* FALLTHROUGH */ 609 case RTM_GET: 610 rtm->rtm_addrs |= RTA_DST; 611 } 612 #define NEXTADDR(w, s) \ 613 if (rtm->rtm_addrs & (w)) { \ 614 (void)memcpy(cp, &s, sizeof(s)); cp += sizeof(s);} 615 616 NEXTADDR(RTA_DST, sin_m); 617 NEXTADDR(RTA_GATEWAY, sdl_m); 618 NEXTADDR(RTA_NETMASK, so_mask); 619 620 rtm->rtm_msglen = cp - (char *)&m_rtmsg; 621 doit: 622 l = rtm->rtm_msglen; 623 rtm->rtm_seq = ++seq; 624 rtm->rtm_type = cmd; 625 if ((rlen = write(s, (char *)&m_rtmsg, l)) < 0) { 626 if (errno != ESRCH || cmd != RTM_DELETE) { 627 warn("writing to routing socket"); 628 return (-1); 629 } 630 } 631 do { 632 l = read(s, (char *)&m_rtmsg, sizeof(m_rtmsg)); 633 } while (l > 0 && (rtm->rtm_seq != seq || rtm->rtm_pid != pid)); 634 if (l < 0) 635 warn("read from routing socket"); 636 return (0); 637 } 638 639 int 640 getinetaddr(host, inap) 641 const char *host; 642 struct in_addr *inap; 643 { 644 struct hostent *hp; 645 646 if (inet_aton(host, inap) == 1) 647 return (0); 648 if ((hp = gethostbyname(host)) == NULL) { 649 warnx("%s: %s\n", host, hstrerror(h_errno)); 650 return (-1); 651 } 652 (void)memcpy(inap, hp->h_addr, sizeof(*inap)); 653 return (0); 654 } 655
Indexes created Tue Sep 30 17:09:57 GMT 2025