arp.c revision 1.65
1 /* $NetBSD: arp.c,v 1.65 2019/02/28 01:20:25 nonaka 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. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 #ifndef lint 37 __COPYRIGHT("@(#) Copyright (c) 1984, 1993\ 38 The Regents of the University of California. All rights reserved."); 39 #endif /* not lint */ 40 41 #ifndef lint 42 #if 0 43 static char sccsid[] = "@(#)arp.c 8.3 (Berkeley) 4/28/95"; 44 #else 45 __RCSID("$NetBSD: arp.c,v 1.65 2019/02/28 01:20:25 nonaka Exp $"); 46 #endif 47 #endif /* not lint */ 48 49 /* 50 * arp - display, set, and delete arp table entries 51 */ 52 53 #include <sys/param.h> 54 #include <sys/file.h> 55 #include <sys/socket.h> 56 #include <sys/sysctl.h> 57 #include <sys/ioctl.h> 58 59 #include <net/if.h> 60 #include <net/if_dl.h> 61 #include <net/if_ether.h> 62 #include <net/if_types.h> 63 #include <net/route.h> 64 #include <netinet/in.h> 65 #include <netinet/if_inarp.h> 66 #include <arpa/inet.h> 67 68 #include <err.h> 69 #include <errno.h> 70 #include <netdb.h> 71 #include <nlist.h> 72 #include <paths.h> 73 #include <stdio.h> 74 #include <stdlib.h> 75 #include <string.h> 76 #include <unistd.h> 77 #include <ifaddrs.h> 78 79 #include "prog_ops.h" 80 81 static int is_llinfo(const struct sockaddr_dl *, int); 82 static int delete_one(struct rt_msghdr *); 83 static void dump(uint32_t); 84 static void delete(const char *, const char *); 85 static void sdl_print(const struct sockaddr_dl *); 86 static int getifname(u_int16_t, char *, size_t); 87 static int atosdl(const char *, struct sockaddr_dl *); 88 static int file(const char *); 89 static void get(const char *); 90 static int getinetaddr(const char *, struct in_addr *); 91 static int getsocket(void); 92 static int getetheraddr(struct in_addr, struct sockaddr_dl *); 93 static struct rt_msghdr * rtmsg(const int, const int, struct rt_msghdr *, 94 const struct sockaddr_inarp *, const struct sockaddr_dl *); 95 static int set(int, char **); 96 static void usage(void) __dead; 97 98 static int aflag, nflag, vflag; 99 static struct sockaddr_in so_mask = { 100 .sin_len = 8, 101 .sin_addr = { 102 .s_addr = 0xffffffff 103 } 104 }; 105 static struct sockaddr_inarp blank_sin = { 106 .sin_len = sizeof(blank_sin), 107 .sin_family = AF_INET 108 }; 109 static struct sockaddr_dl blank_sdl = { 110 .sdl_len = sizeof(blank_sdl), 111 .sdl_family = AF_LINK 112 }; 113 114 static int expire_time, flags, export_only, doing_proxy, found_entry; 115 116 int 117 main(int argc, char **argv) 118 { 119 int ch; 120 int op = 0; 121 122 setprogname(argv[0]); 123 124 while ((ch = getopt(argc, argv, "andsfv")) != -1) 125 switch((char)ch) { 126 case 'a': 127 aflag = 1; 128 break; 129 case 'd': 130 case 's': 131 case 'f': 132 if (op) 133 usage(); 134 op = ch; 135 break; 136 case 'n': 137 nflag = 1; 138 break; 139 case 'v': 140 vflag = 1; 141 break; 142 default: 143 usage(); 144 } 145 argc -= optind; 146 argv += optind; 147 148 if (!op && aflag) 149 op = 'a'; 150 151 if (prog_init && prog_init() == -1) 152 err(1, "init failed"); 153 154 switch((char)op) { 155 case 'a': 156 dump(0); 157 break; 158 case 'd': 159 if (aflag && argc == 0) 160 delete(NULL, NULL); 161 else { 162 if (aflag || argc < 1 || argc > 2) 163 usage(); 164 delete(argv[0], argv[1]); 165 } 166 break; 167 case 's': 168 if (argc < 2 || argc > 7) 169 usage(); 170 return (set(argc, argv) ? 1 : 0); 171 case 'f': 172 if (argc != 1) 173 usage(); 174 return (file(argv[0])); 175 default: 176 if (argc != 1) 177 usage(); 178 get(argv[0]); 179 break; 180 } 181 return (0); 182 } 183 184 /* 185 * Process a file to set standard arp entries 186 */ 187 static int 188 file(const char *name) 189 { 190 char *line, *argv[5]; 191 int i, retval; 192 FILE *fp; 193 194 if (!strcmp(name, "-")) { 195 fp = stdin; 196 } else { 197 fp = fopen(name, "r"); 198 if (fp == NULL) { 199 err(1, "Cannot open %s", name); 200 } 201 } 202 retval = 0; 203 for (; (line = fparseln(fp, NULL, NULL, NULL, 0)) != NULL; free(line)) { 204 char **ap, *inputstring; 205 206 inputstring = line; 207 for (ap = argv; ap < &argv[sizeof(argv) / sizeof(argv[0])] && 208 (*ap = stresep(&inputstring, " \t", '\\')) != NULL;) { 209 if (**ap != '\0') 210 ap++; 211 } 212 i = ap - argv; 213 if (i < 2) { 214 warnx("bad line: %s", line); 215 retval = 1; 216 continue; 217 } 218 if (set(i, argv)) 219 retval = 1; 220 } 221 if (fp != stdin) 222 (void)fclose(fp); 223 return retval; 224 } 225 226 static int 227 getsocket(void) 228 { 229 int s; 230 s = prog_socket(PF_ROUTE, SOCK_RAW, 0); 231 if (s < 0) 232 err(1, "socket"); 233 return s; 234 } 235 236 static int 237 getlink(const char *name, struct sockaddr_dl *sdl) 238 { 239 struct ifaddrs *ifap, *ifa; 240 241 if (getifaddrs(&ifap) != 0) { 242 warn("getifaddrs"); 243 return 0; 244 } 245 246 for (ifa = ifap; ifa; ifa = ifa->ifa_next) { 247 if (ifa->ifa_addr->sa_family != AF_LINK) 248 continue; 249 if (strcmp(ifa->ifa_name, name) != 0) 250 continue; 251 memcpy(sdl, ifa->ifa_addr, sizeof(*sdl)); 252 freeifaddrs(ifap); 253 return 1; 254 } 255 freeifaddrs(ifap); 256 return 0; 257 } 258 259 /* 260 * Set an individual arp entry 261 */ 262 static int 263 set(int argc, char **argv) 264 { 265 struct sockaddr_inarp *sina; 266 struct sockaddr_dl *sdl = NULL; 267 struct rt_msghdr *rtm; 268 char *host = argv[0], *eaddr; 269 struct sockaddr_inarp sin_m = blank_sin; /* struct copy */ 270 struct sockaddr_dl sdl_m = blank_sdl; /* struct copy */ 271 int s; 272 273 eaddr = argv[1]; 274 275 s = getsocket(); 276 argc -= 2; 277 argv += 2; 278 279 if (getinetaddr(host, &sin_m.sin_addr) == -1) { 280 prog_close(s); 281 return (1); 282 } 283 if (strcmp(eaddr, "auto") != 0 && atosdl(eaddr, &sdl_m)) 284 warnx("invalid link-level address '%s'", eaddr); 285 doing_proxy = flags = export_only = expire_time = 0; 286 for (; argc-- > 0; argv++) { 287 if (strncmp(argv[0], "temp", 4) == 0) { 288 struct timeval timev; 289 (void)gettimeofday(&timev, 0); 290 expire_time = timev.tv_sec + 20 * 60; 291 } 292 else if (strncmp(argv[0], "pub", 3) == 0) { 293 flags |= RTF_ANNOUNCE; 294 doing_proxy = 1; 295 if (argc && strncmp(argv[1], "pro", 3) == 0) { 296 export_only = 1; 297 argc--; argv++; 298 } 299 } else if (strncmp(argv[0], "trail", 5) == 0) { 300 warnx("%s: Sending trailers is no longer supported", 301 host); 302 } else if (strcmp(argv[0], "ifscope") == 0) { 303 if (argc == 0) { 304 warnx("missing interface for ifscope"); 305 continue; 306 } 307 argc--; 308 argv++; 309 if (!getlink(argv[0], &sdl_m)) 310 warnx("cannot get link address for %s", argv[0]); 311 } 312 313 } 314 if (doing_proxy && strcmp(eaddr, "auto") == 0) { 315 if (getetheraddr(sin_m.sin_addr, &sdl_m) == -1) { 316 prog_close(s); 317 return 1; 318 } 319 } 320 tryagain: 321 rtm = rtmsg(s, RTM_GET, NULL, &sin_m, &sdl_m); 322 if (rtm == NULL) { 323 warn("%s", host); 324 prog_close(s); 325 return (1); 326 } 327 sina = (struct sockaddr_inarp *)(void *)(rtm + 1); 328 sdl = (struct sockaddr_dl *)(void *)(RT_ROUNDUP(sina->sin_len) + 329 (char *)(void *)sina); 330 if (sina->sin_addr.s_addr == sin_m.sin_addr.s_addr) { 331 if (is_llinfo(sdl, rtm->rtm_flags)) 332 goto overwrite; 333 if (doing_proxy == 0) { 334 warnx("set: can only proxy for %s", host); 335 prog_close(s); 336 return (1); 337 } 338 if (sin_m.sin_other & SIN_PROXY) { 339 warnx("set: proxy entry exists for non 802 device"); 340 prog_close(s); 341 return (1); 342 } 343 sin_m.sin_other = SIN_PROXY; 344 export_only = 1; 345 goto tryagain; 346 } 347 overwrite: 348 if (sdl->sdl_family != AF_LINK) { 349 warnx("cannot intuit interface index and type for %s", 350 host); 351 prog_close(s); 352 return (1); 353 } 354 sdl_m.sdl_type = sdl->sdl_type; 355 sdl_m.sdl_index = sdl->sdl_index; 356 sin_m.sin_other = 0; 357 if (doing_proxy && export_only) 358 sin_m.sin_other = SIN_PROXY; 359 rtm = rtmsg(s, RTM_ADD, NULL, &sin_m, &sdl_m); 360 if (vflag) 361 (void)printf("%s (%s) added\n", host, eaddr); 362 prog_close(s); 363 return (rtm == NULL) ? 1 : 0; 364 } 365 366 /* 367 * Display an individual arp entry 368 */ 369 static void 370 get(const char *host) 371 { 372 struct sockaddr_inarp sin = blank_sin; /* struct copy */ 373 374 if (getinetaddr(host, &sin.sin_addr) == -1) 375 exit(1); 376 dump(sin.sin_addr.s_addr); 377 if (found_entry == 0) 378 errx(1, "%s (%s) -- no entry", host, inet_ntoa(sin.sin_addr)); 379 } 380 381 382 static int 383 is_llinfo(const struct sockaddr_dl *sdl, int rtflags) 384 { 385 if (sdl->sdl_family != AF_LINK || 386 (rtflags & (RTF_LLDATA|RTF_GATEWAY)) != RTF_LLDATA) 387 return 0; 388 389 switch (sdl->sdl_type) { 390 case IFT_ETHER: 391 case IFT_FDDI: 392 case IFT_ISO88023: 393 case IFT_ISO88024: 394 case IFT_ISO88025: 395 case IFT_ARCNET: 396 return 1; 397 default: 398 return 0; 399 } 400 } 401 402 /* 403 * Delete an arp entry 404 */ 405 int 406 delete_one(struct rt_msghdr *rtm) 407 { 408 struct sockaddr_inarp *sina; 409 struct sockaddr_dl *sdl; 410 int s; 411 412 s = getsocket(); 413 sina = (struct sockaddr_inarp *)(void *)(rtm + 1); 414 sdl = (struct sockaddr_dl *)(void *)(RT_ROUNDUP(sina->sin_len) + 415 (char *)(void *)sina); 416 if (sdl->sdl_family != AF_LINK) { 417 prog_close(s); 418 return (1); 419 } 420 rtm = rtmsg(s, RTM_DELETE, rtm, sina, sdl); 421 prog_close(s); 422 if (rtm == NULL) 423 return (1); 424 return (0); 425 } 426 427 /* 428 * Dump the entire arp table 429 */ 430 void 431 dump(uint32_t addr) 432 { 433 int mib[6]; 434 size_t needed; 435 char ifname[IFNAMSIZ]; 436 char *lim, *buf, *next; 437 const char *host; 438 struct rt_msghdr *rtm; 439 struct sockaddr_inarp *sina; 440 struct sockaddr_dl *sdl; 441 struct hostent *hp; 442 443 mib[0] = CTL_NET; 444 mib[1] = PF_ROUTE; 445 mib[2] = 0; 446 mib[3] = AF_INET; 447 mib[4] = NET_RT_FLAGS; 448 mib[5] = 0; 449 if (prog_sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) 450 err(1, "route-sysctl-estimate"); 451 if (needed == 0) 452 return; 453 if ((buf = malloc(needed)) == NULL) 454 err(1, "malloc"); 455 if (prog_sysctl(mib, 6, buf, &needed, NULL, 0) < 0) 456 err(1, "actual retrieval of routing table"); 457 lim = buf + needed; 458 for (next = buf; next < lim; next += rtm->rtm_msglen) { 459 rtm = (struct rt_msghdr *)(void *)next; 460 sina = (struct sockaddr_inarp *)(void *)(rtm + 1); 461 sdl = (struct sockaddr_dl *)(void *) 462 (RT_ROUNDUP(sina->sin_len) + (char *)(void *)sina); 463 if (addr) { 464 if (addr != sina->sin_addr.s_addr) 465 continue; 466 found_entry = 1; 467 } 468 if (nflag == 0) 469 hp = gethostbyaddr((const char *)(void *) 470 &(sina->sin_addr), 471 sizeof sina->sin_addr, AF_INET); 472 else 473 hp = NULL; 474 475 host = hp ? hp->h_name : "?"; 476 477 (void)printf("%s (%s) at ", host, inet_ntoa(sina->sin_addr)); 478 if (sdl->sdl_alen) 479 sdl_print(sdl); 480 else 481 (void)printf("(incomplete)"); 482 483 if (sdl->sdl_index) { 484 if (getifname(sdl->sdl_index, ifname, sizeof(ifname)) == 0) 485 (void)printf(" on %s", ifname); 486 } 487 488 if (rtm->rtm_rmx.rmx_expire == 0) 489 (void)printf(" permanent"); 490 if (sina->sin_other & SIN_PROXY) 491 (void)printf(" published (proxy only)"); 492 if (rtm->rtm_addrs & RTA_NETMASK) { 493 sina = (struct sockaddr_inarp *)(void *) 494 (RT_ROUNDUP(sdl->sdl_len) + (char *)(void *)sdl); 495 if (sina->sin_addr.s_addr == 0xffffffff) 496 (void)printf(" published"); 497 if (sina->sin_len != 8) 498 (void)printf("(weird)"); 499 } 500 (void)printf("\n"); 501 } 502 free(buf); 503 } 504 505 /* 506 * Delete the entire arp table 507 */ 508 void 509 delete(const char *host, const char *info) 510 { 511 int mib[6]; 512 char addr[sizeof("000.000.000.000\0")]; 513 size_t needed; 514 char *lim, *buf, *next; 515 struct rt_msghdr *rtm; 516 struct sockaddr_inarp *sina; 517 struct sockaddr_inarp sin_m = blank_sin; /* struct copy */ 518 bool found = false; 519 520 if (host != NULL) { 521 int ret = getinetaddr(host, &sin_m.sin_addr); 522 if (ret == -1) 523 return; 524 } 525 if (info && strncmp(info, "pro", 3) == 0) 526 sin_m.sin_other = SIN_PROXY; 527 528 retry: 529 mib[0] = CTL_NET; 530 mib[1] = PF_ROUTE; 531 mib[2] = 0; 532 mib[3] = AF_INET; 533 mib[4] = NET_RT_FLAGS; 534 mib[5] = RTF_LLDATA; 535 if (prog_sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) 536 err(1, "route-sysctl-estimate"); 537 if (needed == 0) 538 return; 539 if ((buf = malloc(needed)) == NULL) 540 err(1, "malloc"); 541 if (prog_sysctl(mib, 6, buf, &needed, NULL, 0) < 0) { 542 free(buf); 543 if (errno == ENOBUFS) 544 goto retry; 545 err(1, "actual retrieval of routing table"); 546 } 547 lim = buf + needed; 548 549 for (next = buf; next < lim; next += rtm->rtm_msglen) { 550 int ret; 551 rtm = (struct rt_msghdr *)(void *)next; 552 sina = (struct sockaddr_inarp *)(void *)(rtm + 1); 553 if (host != NULL && 554 sina->sin_addr.s_addr != sin_m.sin_addr.s_addr) 555 continue; 556 found = true; 557 ret = delete_one(rtm); 558 if (vflag && ret == 0) { 559 snprintf(addr, sizeof(addr), "%s", 560 inet_ntoa(sina->sin_addr)); 561 (void)printf("%s (%s) deleted\n", 562 host != NULL ? host : addr, addr); 563 } 564 } 565 if (host != NULL && !found) 566 warnx("delete: can't locate %s", host); 567 free(buf); 568 } 569 570 void 571 sdl_print(const struct sockaddr_dl *sdl) 572 { 573 char hbuf[NI_MAXHOST]; 574 575 if (getnameinfo((const struct sockaddr *)(const void *)sdl, 576 (socklen_t)sdl->sdl_len, 577 hbuf, sizeof(hbuf), NULL, 0, NI_NUMERICHOST) != 0) 578 (void)printf("<invalid>"); 579 else 580 (void)printf("%s", hbuf); 581 } 582 583 static int 584 atosdl(const char *ss, struct sockaddr_dl *sdl) 585 { 586 int i; 587 unsigned long b; 588 char *endp; 589 char *p; 590 char *t, *r; 591 592 p = LLADDR(sdl); 593 endp = ((char *)(void *)sdl) + sdl->sdl_len; 594 i = 0; 595 596 b = strtoul(ss, &t, 16); 597 if (b > 255 || t == ss) 598 return 1; 599 600 *p++ = (char)b; 601 ++i; 602 while ((p < endp) && (*t++ == ':')) { 603 b = strtoul(t, &r, 16); 604 if (b > 255 || r == t) 605 break; 606 *p++ = (char)b; 607 ++i; 608 t = r; 609 } 610 sdl->sdl_alen = i; 611 612 return 0; 613 } 614 615 static void 616 usage(void) 617 { 618 const char *progname; 619 620 progname = getprogname(); 621 (void)fprintf(stderr, "Usage: %s [-n] hostname\n", progname); 622 (void)fprintf(stderr, " %s [-nv] -a\n", progname); 623 (void)fprintf(stderr, " %s [-v] -d [-a|hostname [proxy]]\n", 624 progname); 625 (void)fprintf(stderr, " %s -s hostname ether_addr [temp] [pub [proxy]]\n", 626 progname); 627 (void)fprintf(stderr, " %s -f filename\n", progname); 628 exit(1); 629 } 630 631 static struct rt_msghdr * 632 rtmsg(const int s, const int cmd, struct rt_msghdr *_rtm, 633 const struct sockaddr_inarp *sin, const struct sockaddr_dl *sdl) 634 { 635 static int seq; 636 struct rt_msghdr *rtm = _rtm; 637 char *cp; 638 int l; 639 static struct { 640 struct rt_msghdr m_rtm; 641 char m_space[512]; 642 } m_rtmsg; 643 pid_t pid; 644 645 errno = 0; 646 if (rtm != NULL) { 647 memcpy(&m_rtmsg, rtm, rtm->rtm_msglen); 648 rtm = &m_rtmsg.m_rtm; 649 goto doit; 650 } 651 (void)memset(&m_rtmsg, 0, sizeof(m_rtmsg)); 652 rtm = &m_rtmsg.m_rtm; 653 cp = m_rtmsg.m_space; 654 655 rtm->rtm_flags = flags; 656 rtm->rtm_version = RTM_VERSION; 657 658 switch (cmd) { 659 default: 660 errx(1, "internal wrong cmd"); 661 /*NOTREACHED*/ 662 case RTM_ADD: 663 rtm->rtm_addrs |= RTA_GATEWAY; 664 rtm->rtm_rmx.rmx_expire = expire_time; 665 rtm->rtm_inits = RTV_EXPIRE; 666 rtm->rtm_flags |= (RTF_HOST | RTF_STATIC | RTF_LLDATA); 667 if (doing_proxy) { 668 if (!export_only) { 669 rtm->rtm_addrs |= RTA_NETMASK; 670 rtm->rtm_flags &= ~RTF_HOST; 671 } 672 } 673 rtm->rtm_addrs |= RTA_DST; 674 break; 675 case RTM_GET: 676 rtm->rtm_flags |= RTF_LLDATA; 677 rtm->rtm_addrs |= RTA_DST | RTA_GATEWAY; 678 } 679 680 #define NEXTADDR(w, s) \ 681 if (rtm->rtm_addrs & (w)) { \ 682 (void)memcpy(cp, &s, \ 683 (size_t)((const struct sockaddr *)&s)->sa_len); \ 684 RT_ADVANCE(cp, ((const struct sockaddr *)&s)); \ 685 } 686 687 NEXTADDR(RTA_DST, *sin); 688 NEXTADDR(RTA_GATEWAY, *sdl); 689 NEXTADDR(RTA_NETMASK, so_mask); 690 691 rtm->rtm_msglen = cp - (char *)(void *)&m_rtmsg; 692 doit: 693 l = rtm->rtm_msglen; 694 rtm->rtm_seq = ++seq; 695 rtm->rtm_type = cmd; 696 if (prog_write(s, &m_rtmsg, (size_t)l) < 0) { 697 if (errno != ESRCH || cmd != RTM_DELETE) { 698 warn("writing to routing socket"); 699 return NULL; 700 } 701 } 702 703 pid = prog_getpid(); 704 do { 705 l = prog_read(s, &m_rtmsg, sizeof(m_rtmsg)); 706 } while (l > 0 && (rtm->rtm_seq != seq || rtm->rtm_pid != pid)); 707 if (l < 0) 708 warn("read from routing socket"); 709 return rtm; 710 } 711 712 static int 713 getinetaddr(const char *host, struct in_addr *inap) 714 { 715 struct hostent *hp; 716 717 if (inet_aton(host, inap) == 1) 718 return (0); 719 if ((hp = gethostbyname(host)) == NULL) { 720 warnx("%s: %s", host, hstrerror(h_errno)); 721 return (-1); 722 } 723 (void)memcpy(inap, hp->h_addr, sizeof(*inap)); 724 return (0); 725 } 726 727 static int 728 getifname(u_int16_t ifindex, char *ifname, size_t l) 729 { 730 int i; 731 struct ifaddrs *addr; 732 const struct sockaddr_dl *sdl; 733 static struct ifaddrs* ifaddrs = NULL; 734 735 if (ifaddrs == NULL) { 736 i = getifaddrs(&ifaddrs); 737 if (i != 0) 738 err(1, "getifaddrs"); 739 } 740 741 for (addr = ifaddrs; addr; addr = addr->ifa_next) { 742 if (addr->ifa_addr == NULL || 743 addr->ifa_addr->sa_family != AF_LINK) 744 continue; 745 746 sdl = (const struct sockaddr_dl *)(void *)addr->ifa_addr; 747 if (sdl && sdl->sdl_index == ifindex) { 748 (void) strlcpy(ifname, addr->ifa_name, l); 749 return 0; 750 } 751 } 752 753 return -1; 754 } 755 756 static int 757 getetheraddr(struct in_addr ipaddr, struct sockaddr_dl *sdl) 758 { 759 struct ifaddrs *ifaddrs, *addr; 760 in_addr_t ina, mask; 761 char ifname[IFNAMSIZ]; 762 763 if (getifaddrs(&ifaddrs) != 0) { 764 warn("getifaddrs"); 765 return -1; 766 } 767 768 for (addr = ifaddrs; addr; addr = addr->ifa_next) { 769 if (addr->ifa_addr == NULL || 770 addr->ifa_addr->sa_family != AF_INET) 771 continue; 772 if ((addr->ifa_flags & (IFF_UP|IFF_BROADCAST|IFF_POINTOPOINT| 773 IFF_LOOPBACK|IFF_NOARP)) != (IFF_UP|IFF_BROADCAST)) 774 continue; 775 776 mask = ((struct sockaddr_in *)(void *)addr->ifa_netmask)->sin_addr.s_addr; 777 ina = ((struct sockaddr_in *)(void *)addr->ifa_addr)->sin_addr.s_addr; 778 if ((ipaddr.s_addr & mask) != (ina & mask)) 779 continue; 780 strlcpy(ifname, addr->ifa_name, sizeof(ifname)); 781 break; 782 } 783 if (addr == NULL) { 784 warnx("No interface matched %s", inet_ntoa(ipaddr)); 785 freeifaddrs(ifaddrs); 786 return -1; 787 } 788 789 for (addr = ifaddrs; addr; addr = addr->ifa_next) { 790 if (addr->ifa_addr == NULL || 791 addr->ifa_addr->sa_family != AF_LINK) 792 continue; 793 if (strcmp(ifname, addr->ifa_name) != 0) 794 continue; 795 memcpy(sdl, addr->ifa_addr, sizeof(*sdl)); 796 freeifaddrs(ifaddrs); 797 return 0; 798 } 799 warnx("No link address for interface %s", ifname); 800 freeifaddrs(ifaddrs); 801 return -1; 802 } 803
Indexes created Tue Sep 30 20:09:53 GMT 2025