1 /* $OpenBSD: arp.c,v 1.52 2013/03/21 04:43:17 deraadt Exp $ */ 2 /* $NetBSD: arp.c,v 1.12 1995/04/24 13:25:18 cgd Exp $ */ 3 4 /* 5 * Copyright (c) 1984, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * Sun Microsystems, Inc. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 /* 37 * arp - display, set, delete arp table entries and wake up hosts. 38 */ 39 40 #include <sys/param.h> 41 #include <sys/file.h> 42 #include <sys/socket.h> 43 #include <sys/sysctl.h> 44 #include <sys/ioctl.h> 45 #include <net/bpf.h> 46 #include <net/if.h> 47 #include <net/if_dl.h> 48 #include <net/if_types.h> 49 #include <net/route.h> 50 #include <netinet/in.h> 51 #include <netinet/if_ether.h> 52 #include <arpa/inet.h> 53 54 #include <netdb.h> 55 #include <errno.h> 56 #include <err.h> 57 #include <stdio.h> 58 #include <stdlib.h> 59 #include <string.h> 60 #include <paths.h> 61 #include <unistd.h> 62 #include <ifaddrs.h> 63 64 int delete(const char *, const char *); 65 void search(in_addr_t addr, void (*action)(struct sockaddr_dl *sdl, 66 struct sockaddr_inarp *sin, struct rt_msghdr *rtm)); 67 void print_entry(struct sockaddr_dl *sdl, 68 struct sockaddr_inarp *sin, struct rt_msghdr *rtm); 69 void nuke_entry(struct sockaddr_dl *sdl, 70 struct sockaddr_inarp *sin, struct rt_msghdr *rtm); 71 int wake(const char *ether_addr, const char *iface); 72 void ether_print(const char *); 73 int file(char *); 74 int get(const char *); 75 int getinetaddr(const char *, struct in_addr *); 76 void getsocket(void); 77 int rtmsg(int); 78 int set(int, char **); 79 void usage(void); 80 81 static pid_t pid; 82 static int replace; /* replace entries when adding */ 83 static int nflag; /* no reverse dns lookups */ 84 static int aflag; /* do it for all entries */ 85 static int s = -1; 86 static int rdomain = 0; 87 88 extern int h_errno; 89 90 /* ROUNDUP() is nasty, but it is identical to what's in the kernel. */ 91 #define ROUNDUP(a) \ 92 ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long)) 93 94 /* which function we're supposed to do */ 95 #define F_GET 1 96 #define F_SET 2 97 #define F_FILESET 3 98 #define F_DELETE 4 99 #define F_WAKE 5 100 101 int 102 main(int argc, char *argv[]) 103 { 104 int ch, func = 0, rtn; 105 const char *errstr; 106 107 pid = getpid(); 108 opterr = 0; 109 rdomain = getrtable(); 110 while ((ch = getopt(argc, argv, "andsFfV:W")) != -1) { 111 switch (ch) { 112 case 'a': 113 aflag = 1; 114 break; 115 case 'n': 116 nflag = 1; 117 break; 118 case 'd': 119 if (func) 120 usage(); 121 func = F_DELETE; 122 break; 123 case 's': 124 if (func) 125 usage(); 126 func = F_SET; 127 break; 128 case 'F': 129 replace = 1; 130 break; 131 case 'f': 132 if (func) 133 usage(); 134 func = F_FILESET; 135 break; 136 case 'V': 137 rdomain = strtonum(optarg, 0, RT_TABLEID_MAX, &errstr); 138 if (errstr != NULL) { 139 warn("bad rdomain: %s", errstr); 140 usage(); 141 } 142 break; 143 case 'W': 144 if (func) 145 usage(); 146 func = F_WAKE; 147 break; 148 default: 149 usage(); 150 break; 151 } 152 } 153 argc -= optind; 154 argv += optind; 155 156 if (!func) 157 func = F_GET; 158 rtn = 0; 159 160 switch (func) { 161 case F_GET: 162 if (aflag && argc == 0) 163 search(0, print_entry); 164 else if (!aflag && argc == 1) 165 rtn = get(argv[0]); 166 else 167 usage(); 168 break; 169 case F_SET: 170 if (argc < 2 || argc > 5) 171 usage(); 172 if (replace) 173 delete(argv[0], NULL); 174 rtn = set(argc, argv) ? 1 : 0; 175 break; 176 case F_DELETE: 177 if (aflag && argc == 0) 178 search(0, nuke_entry); 179 else if (!aflag && argc == 1) 180 rtn = delete(argv[0], argv[1]); 181 else 182 usage(); 183 break; 184 case F_FILESET: 185 if (argc != 1) 186 usage(); 187 rtn = file(argv[0]); 188 break; 189 case F_WAKE: 190 if (aflag || nflag || replace || rdomain > 0) 191 usage(); 192 if (argc == 1) 193 rtn = wake(argv[0], NULL); 194 else if (argc == 2) 195 rtn = wake(argv[0], argv[1]); 196 else 197 usage(); 198 break; 199 } 200 return (rtn); 201 } 202 203 /* 204 * Process a file to set standard arp entries 205 */ 206 int 207 file(char *name) 208 { 209 char line[100], arg[5][50], *args[5]; 210 int i, retval; 211 FILE *fp; 212 213 if ((fp = fopen(name, "r")) == NULL) 214 err(1, "cannot open %s", name); 215 args[0] = &arg[0][0]; 216 args[1] = &arg[1][0]; 217 args[2] = &arg[2][0]; 218 args[3] = &arg[3][0]; 219 args[4] = &arg[4][0]; 220 retval = 0; 221 while (fgets(line, sizeof(line), fp) != NULL) { 222 i = sscanf(line, "%49s %49s %49s %49s %49s", arg[0], arg[1], 223 arg[2], arg[3], arg[4]); 224 if (i < 2) { 225 warnx("bad line: %s", line); 226 retval = 1; 227 continue; 228 } 229 if (replace) 230 delete(arg[0], NULL); 231 if (set(i, args)) 232 retval = 1; 233 } 234 fclose(fp); 235 return (retval); 236 } 237 238 void 239 getsocket(void) 240 { 241 if (s >= 0) 242 return; 243 s = socket(PF_ROUTE, SOCK_RAW, 0); 244 if (s < 0) 245 err(1, "socket"); 246 } 247 248 struct sockaddr_in so_mask = { 8, 0, 0, { 0xffffffff } }; 249 struct sockaddr_inarp blank_sin = { sizeof(blank_sin), AF_INET }, sin_m; 250 struct sockaddr_dl blank_sdl = { sizeof(blank_sdl), AF_LINK }, sdl_m; 251 int expire_time, flags, export_only, doing_proxy, 252 found_entry; 253 struct { 254 struct rt_msghdr m_rtm; 255 char m_space[512]; 256 } m_rtmsg; 257 258 /* 259 * Set an individual arp entry 260 */ 261 int 262 set(int argc, char *argv[]) 263 { 264 struct sockaddr_inarp *sin; 265 struct sockaddr_dl *sdl; 266 struct rt_msghdr *rtm; 267 char *eaddr = argv[1], *host = argv[0]; 268 struct ether_addr *ea; 269 270 sin = &sin_m; 271 rtm = &(m_rtmsg.m_rtm); 272 273 getsocket(); 274 argc -= 2; 275 argv += 2; 276 sdl_m = blank_sdl; /* struct copy */ 277 sin_m = blank_sin; /* struct copy */ 278 if (getinetaddr(host, &sin->sin_addr) == -1) 279 return (1); 280 ea = ether_aton(eaddr); 281 if (ea == NULL) 282 errx(1, "invalid ethernet address: %s", eaddr); 283 memcpy(LLADDR(&sdl_m), ea, sizeof(*ea)); 284 sdl_m.sdl_alen = 6; 285 doing_proxy = flags = export_only = expire_time = 0; 286 while (argc-- > 0) { 287 if (strncmp(argv[0], "temp", 4) == 0) { 288 struct timeval time; 289 290 gettimeofday(&time, 0); 291 expire_time = time.tv_sec + 20 * 60; 292 if (flags & RTF_PERMANENT_ARP) { 293 /* temp or permanent, not both */ 294 usage(); 295 return (0); 296 } 297 } else if (strncmp(argv[0], "pub", 3) == 0) { 298 flags |= RTF_ANNOUNCE; 299 doing_proxy = SIN_PROXY; 300 } else if (strncmp(argv[0], "permanent", 9) == 0) { 301 flags |= RTF_PERMANENT_ARP; 302 if (expire_time != 0) { 303 /* temp or permanent, not both */ 304 usage(); 305 return (0); 306 } 307 } else if (strncmp(argv[0], "trail", 5) == 0) 308 printf("%s: Sending trailers is no longer supported\n", 309 host); 310 311 argv++; 312 } 313 314 tryagain: 315 if (rtmsg(RTM_GET) < 0) { 316 warn("%s", host); 317 return (1); 318 } 319 sin = (struct sockaddr_inarp *)((char *)rtm + rtm->rtm_hdrlen); 320 sdl = (struct sockaddr_dl *)(ROUNDUP(sin->sin_len) + (char *)sin); 321 if (sin->sin_addr.s_addr == sin_m.sin_addr.s_addr) { 322 if (sdl->sdl_family == AF_LINK && 323 (rtm->rtm_flags & RTF_LLINFO) && 324 !(rtm->rtm_flags & RTF_GATEWAY)) 325 switch (sdl->sdl_type) { 326 case IFT_ETHER: 327 case IFT_FDDI: 328 case IFT_ISO88023: 329 case IFT_ISO88024: 330 case IFT_ISO88025: 331 case IFT_CARP: 332 goto overwrite; 333 } 334 335 if (doing_proxy == 0) { 336 printf("set: can only proxy for %s\n", host); 337 return (1); 338 } 339 if (sin_m.sin_other & SIN_PROXY) { 340 printf("set: proxy entry exists for non 802 device\n"); 341 return (1); 342 } 343 sin_m.sin_other = SIN_PROXY; 344 export_only = 1; 345 goto tryagain; 346 } 347 348 overwrite: 349 if (sdl->sdl_family != AF_LINK) { 350 printf("cannot intuit interface index and type for %s\n", host); 351 return (1); 352 } 353 sdl_m.sdl_type = sdl->sdl_type; 354 sdl_m.sdl_index = sdl->sdl_index; 355 return (rtmsg(RTM_ADD)); 356 } 357 358 /* 359 * Display an individual arp entry 360 */ 361 int 362 get(const char *host) 363 { 364 struct sockaddr_inarp *sin; 365 366 sin = &sin_m; 367 sin_m = blank_sin; /* struct copy */ 368 if (getinetaddr(host, &sin->sin_addr) == -1) 369 exit(1); 370 search(sin->sin_addr.s_addr, print_entry); 371 if (found_entry == 0) { 372 printf("%s (%s) -- no entry\n", host, inet_ntoa(sin->sin_addr)); 373 return (1); 374 } 375 return (0); 376 } 377 378 /* 379 * Delete an arp entry 380 */ 381 int 382 delete(const char *host, const char *info) 383 { 384 struct sockaddr_inarp *sin; 385 struct rt_msghdr *rtm; 386 struct sockaddr_dl *sdl; 387 388 sin = &sin_m; 389 rtm = &m_rtmsg.m_rtm; 390 391 if (info && strncmp(info, "pro", 3) ) 392 export_only = 1; 393 getsocket(); 394 sin_m = blank_sin; /* struct copy */ 395 if (getinetaddr(host, &sin->sin_addr) == -1) 396 return (1); 397 tryagain: 398 if (rtmsg(RTM_GET) < 0) { 399 warn("%s", host); 400 return (1); 401 } 402 sin = (struct sockaddr_inarp *)((char *)rtm + rtm->rtm_hdrlen); 403 sdl = (struct sockaddr_dl *)(ROUNDUP(sin->sin_len) + (char *)sin); 404 if (sin->sin_addr.s_addr == sin_m.sin_addr.s_addr) 405 if (sdl->sdl_family == AF_LINK && 406 (rtm->rtm_flags & RTF_LLINFO) && 407 !(rtm->rtm_flags & RTF_GATEWAY)) 408 switch (sdl->sdl_type) { 409 case IFT_ETHER: 410 case IFT_FDDI: 411 case IFT_ISO88023: 412 case IFT_ISO88024: 413 case IFT_ISO88025: 414 case IFT_CARP: 415 goto delete; 416 } 417 418 if (sin_m.sin_other & SIN_PROXY) { 419 warnx("delete: can't locate %s", host); 420 return (1); 421 } else { 422 sin_m.sin_other = SIN_PROXY; 423 goto tryagain; 424 } 425 delete: 426 if (sdl->sdl_family != AF_LINK) { 427 printf("cannot locate %s\n", host); 428 return (1); 429 } 430 if (rtmsg(RTM_DELETE)) 431 return (1); 432 printf("%s (%s) deleted\n", host, inet_ntoa(sin->sin_addr)); 433 return (0); 434 } 435 436 /* 437 * Search the entire arp table, and do some action on matching entries. 438 */ 439 void 440 search(in_addr_t addr, void (*action)(struct sockaddr_dl *sdl, 441 struct sockaddr_inarp *sin, struct rt_msghdr *rtm)) 442 { 443 int mib[7]; 444 size_t needed; 445 char *lim, *buf = NULL, *next; 446 struct rt_msghdr *rtm; 447 struct sockaddr_inarp *sin; 448 struct sockaddr_dl *sdl; 449 450 mib[0] = CTL_NET; 451 mib[1] = PF_ROUTE; 452 mib[2] = 0; 453 mib[3] = AF_INET; 454 mib[4] = NET_RT_FLAGS; 455 mib[5] = RTF_LLINFO; 456 mib[6] = rdomain; 457 while (1) { 458 if (sysctl(mib, 7, NULL, &needed, NULL, 0) == -1) 459 err(1, "route-sysctl-estimate"); 460 if (needed == 0) 461 return; 462 if ((buf = realloc(buf, needed)) == NULL) 463 err(1, "malloc"); 464 if (sysctl(mib, 7, buf, &needed, NULL, 0) == -1) { 465 if (errno == ENOMEM) 466 continue; 467 err(1, "actual retrieval of routing table"); 468 } 469 lim = buf + needed; 470 break; 471 } 472 for (next = buf; next < lim; next += rtm->rtm_msglen) { 473 rtm = (struct rt_msghdr *)next; 474 if (rtm->rtm_version != RTM_VERSION) 475 continue; 476 sin = (struct sockaddr_inarp *)(next + rtm->rtm_hdrlen); 477 sdl = (struct sockaddr_dl *)(sin + 1); 478 if (addr) { 479 if (addr != sin->sin_addr.s_addr) 480 continue; 481 found_entry = 1; 482 } 483 (*action)(sdl, sin, rtm); 484 } 485 free(buf); 486 } 487 488 /* 489 * Display an arp entry 490 */ 491 void 492 print_entry(struct sockaddr_dl *sdl, struct sockaddr_inarp *sin, 493 struct rt_msghdr *rtm) 494 { 495 char ifname[IFNAMSIZ], *host; 496 struct hostent *hp; 497 498 if (nflag == 0) 499 hp = gethostbyaddr((caddr_t)&(sin->sin_addr), 500 sizeof(sin->sin_addr), AF_INET); 501 else 502 hp = 0; 503 if (hp) 504 host = hp->h_name; 505 else { 506 host = "?"; 507 if (h_errno == TRY_AGAIN) 508 nflag = 1; 509 } 510 printf("%s (%s) at ", host, inet_ntoa(sin->sin_addr)); 511 if (sdl->sdl_alen) 512 ether_print(LLADDR(sdl)); 513 else 514 printf("(incomplete)"); 515 if (if_indextoname(sdl->sdl_index, ifname) != NULL) 516 printf(" on %s", ifname); 517 if (rtm->rtm_flags & RTF_PERMANENT_ARP) 518 printf(" permanent"); 519 if (rtm->rtm_rmx.rmx_expire == 0) 520 printf(" static"); 521 if (sin->sin_other & SIN_PROXY) 522 printf(" published (proxy only)"); 523 if (rtm->rtm_addrs & RTA_NETMASK) { 524 sin = (struct sockaddr_inarp *) 525 (ROUNDUP(sdl->sdl_len) + (char *)sdl); 526 if (sin->sin_addr.s_addr == 0xffffffff) 527 printf(" published"); 528 if (sin->sin_len != 8) 529 printf("(weird %d)", sin->sin_len); 530 } 531 printf("\n"); 532 } 533 534 /* 535 * Nuke an arp entry 536 */ 537 void 538 nuke_entry(struct sockaddr_dl *sdl, struct sockaddr_inarp *sin, 539 struct rt_msghdr *rtm) 540 { 541 char ip[20]; 542 543 strlcpy(ip, inet_ntoa(sin->sin_addr), sizeof(ip)); 544 delete(ip, NULL); 545 } 546 547 void 548 ether_print(const char *scp) 549 { 550 const u_char *cp = (u_char *)scp; 551 552 printf("%02x:%02x:%02x:%02x:%02x:%02x", 553 cp[0], cp[1], cp[2], cp[3], cp[4], cp[5]); 554 } 555 556 void 557 usage(void) 558 { 559 fprintf(stderr, "usage: arp [-adn] [-V rdomain] hostname\n"); 560 fprintf(stderr, " arp [-F] [-f file] [-V rdomain] " 561 "-s hostname ether_addr\n" 562 " [temp | permanent] [pub]\n"); 563 fprintf(stderr, " arp -W ether_addr [iface]\n"); 564 exit(1); 565 } 566 567 int 568 rtmsg(int cmd) 569 { 570 static int seq; 571 struct rt_msghdr *rtm; 572 char *cp; 573 int l; 574 575 rtm = &m_rtmsg.m_rtm; 576 cp = m_rtmsg.m_space; 577 errno = 0; 578 579 if (cmd == RTM_DELETE) 580 goto doit; 581 memset(&m_rtmsg, 0, sizeof(m_rtmsg)); 582 rtm->rtm_flags = flags; 583 rtm->rtm_version = RTM_VERSION; 584 rtm->rtm_hdrlen = sizeof(*rtm); 585 rtm->rtm_tableid = rdomain; 586 587 switch (cmd) { 588 default: 589 errx(1, "internal wrong cmd"); 590 /*NOTREACHED*/ 591 case RTM_ADD: 592 rtm->rtm_addrs |= RTA_GATEWAY; 593 rtm->rtm_rmx.rmx_expire = expire_time; 594 rtm->rtm_inits = RTV_EXPIRE; 595 rtm->rtm_flags |= (RTF_HOST | RTF_STATIC); 596 sin_m.sin_other = 0; 597 if (doing_proxy) { 598 if (export_only) 599 sin_m.sin_other = SIN_PROXY; 600 else { 601 rtm->rtm_addrs |= RTA_NETMASK; 602 rtm->rtm_flags &= ~RTF_HOST; 603 } 604 } 605 /* FALLTHROUGH */ 606 case RTM_GET: 607 rtm->rtm_addrs |= RTA_DST; 608 } 609 610 #define NEXTADDR(w, s) \ 611 if (rtm->rtm_addrs & (w)) { \ 612 memcpy(cp, &s, sizeof(s)); \ 613 cp += ROUNDUP(sizeof(s)); \ 614 } 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 (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_version != RTM_VERSION || 634 rtm->rtm_seq != seq || rtm->rtm_pid != pid)); 635 636 if (l < 0) 637 warn("read from routing socket"); 638 return (0); 639 } 640 641 int 642 getinetaddr(const char *host, 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", host, hstrerror(h_errno)); 650 return (-1); 651 } 652 memcpy(inap, hp->h_addr, sizeof(*inap)); 653 return (0); 654 } 655 656 /* 657 * Copyright (c) 2011 Jasper Lievisse Adriaanse <jasper@openbsd.org> 658 * Copyright (C) 2006,2007,2008,2009 Marc Balmer <mbalmer@openbsd.org> 659 * Copyright (C) 2000 Eugene M. Kim. All rights reserved. 660 * 661 * Redistribution and use in source and binary forms, with or without 662 * modification, are permitted provided that the following conditions 663 * are met: 664 * 665 * 1. Redistributions of source code must retain the above copyright 666 * notice, this list of conditions and the following disclaimer. 667 * 2. Author's name may not be used endorse or promote products derived 668 * from this software without specific prior written permission. 669 * 670 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 671 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 672 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 673 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, 674 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 675 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 676 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 677 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 678 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 679 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 680 * POSSIBILITY OF SUCH DAMAGE. 681 */ 682 683 #ifndef BPF_PATH_FORMAT 684 #define BPF_PATH_FORMAT "/dev/bpf%u" 685 #endif 686 687 int do_wakeup(const char *, const char *, int); 688 int get_bpf(void); 689 int bind_if_to_bpf(const char *, int); 690 int get_ether(const char *, struct ether_addr *); 691 int send_frame(int, const struct ether_addr *); 692 693 int 694 wake(const char *ether_addr, const char *iface) 695 { 696 struct ifaddrs *ifa, *ifap; 697 char *pname = NULL; 698 int bpf; 699 700 bpf = get_bpf(); 701 if (bpf == -1) 702 errx(1, "Failed to bind to bpf."); 703 704 if (iface == NULL) { 705 if (getifaddrs(&ifa) == -1) 706 errx(1, "Could not get interface addresses."); 707 708 for (ifap = ifa; ifap != NULL; ifap = ifap->ifa_next){ 709 if (pname && !strcmp(pname, ifap->ifa_name)) 710 continue; 711 pname = ifap->ifa_name; 712 713 /* 714 * We're only interested in sending the WoL frame on 715 * certain interfaces. So skip the loopback interface, 716 * as well as point-to-point and down interfaces. 717 */ 718 if ((ifap->ifa_flags & IFF_LOOPBACK) || 719 (ifap->ifa_flags & IFF_POINTOPOINT) || 720 (!(ifap->ifa_flags & IFF_UP)) || 721 (!(ifap->ifa_flags & IFF_BROADCAST))) 722 continue; 723 724 do_wakeup(ether_addr, ifap->ifa_name, bpf); 725 } 726 freeifaddrs(ifa); 727 } else { 728 do_wakeup(ether_addr, iface, bpf); 729 } 730 731 (void)close(bpf); 732 733 return 0; 734 } 735 736 int 737 do_wakeup(const char *eaddr, const char *iface, int bpf) 738 { 739 struct ether_addr macaddr; 740 741 if (get_ether(eaddr, &macaddr) != 0) 742 errx(1, "Invalid Ethernet address: %s", eaddr); 743 if (bind_if_to_bpf(iface, bpf) != 0) 744 errx(1, "Failed to bind %s to bpf.", iface); 745 if (send_frame(bpf, &macaddr) != 0) 746 errx(1, "Failed to send WoL frame on %s", iface); 747 return 0; 748 } 749 750 int 751 get_bpf(void) 752 { 753 char path[MAXPATHLEN]; 754 int i, fd; 755 756 for (i = 0; ; i++) { 757 if (snprintf(path, sizeof(path), BPF_PATH_FORMAT, i) == -1) 758 return -1; 759 fd = open(path, O_RDWR); 760 if (fd != -1) 761 return fd; 762 if (errno == EBUSY) 763 continue; 764 break; 765 } 766 return -1; 767 } 768 769 int 770 bind_if_to_bpf(const char *ifname, int bpf) 771 { 772 struct ifreq ifr; 773 u_int dlt; 774 775 if (strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name)) >= 776 sizeof(ifr.ifr_name)) 777 return -1; 778 if (ioctl(bpf, BIOCSETIF, &ifr) == -1) 779 return -1; 780 if (ioctl(bpf, BIOCGDLT, &dlt) == -1) 781 return -1; 782 if (dlt != DLT_EN10MB) 783 return -1; 784 return 0; 785 } 786 787 int 788 get_ether(const char *text, struct ether_addr *addr) 789 { 790 struct ether_addr *eaddr; 791 792 eaddr = ether_aton(text); 793 794 if (eaddr == NULL) { 795 if (ether_hostton(text, addr)) 796 return -1; 797 } else { 798 *addr = *eaddr; 799 return 0; 800 } 801 802 return 0; 803 } 804 805 #define SYNC_LEN 6 806 #define DESTADDR_COUNT 16 807 808 int 809 send_frame(int bpf, const struct ether_addr *addr) 810 { 811 struct { 812 struct ether_header hdr; 813 u_char sync[SYNC_LEN]; 814 u_char dest[ETHER_ADDR_LEN * DESTADDR_COUNT]; 815 } __packed pkt; 816 u_char *p; 817 int i; 818 819 (void)memset(&pkt, 0, sizeof(pkt)); 820 (void)memset(&pkt.hdr.ether_dhost, 0xff, sizeof(pkt.hdr.ether_dhost)); 821 pkt.hdr.ether_type = htons(0); 822 (void)memset(pkt.sync, 0xff, SYNC_LEN); 823 for (p = pkt.dest, i = 0; i < DESTADDR_COUNT; p += ETHER_ADDR_LEN, i++) 824 bcopy(addr->ether_addr_octet, p, ETHER_ADDR_LEN); 825 if (write(bpf, &pkt, sizeof(pkt)) != sizeof(pkt)) 826 return (errno); 827 return (0); 828 } 829