arp.c revision 163305
111726Sascarpino/* 211726Sascarpino * Copyright (c) 1984, 1993 311726Sascarpino * The Regents of the University of California. All rights reserved. 411726Sascarpino * 511726Sascarpino * This code is derived from software contributed to Berkeley by 611726Sascarpino * Sun Microsystems, Inc. 711726Sascarpino * 811726Sascarpino * Redistribution and use in source and binary forms, with or without 911726Sascarpino * modification, are permitted provided that the following conditions 1011726Sascarpino * are met: 1111726Sascarpino * 1. Redistributions of source code must retain the above copyright 1211726Sascarpino * notice, this list of conditions and the following disclaimer. 1311726Sascarpino * 2. Redistributions in binary form must reproduce the above copyright 1411726Sascarpino * notice, this list of conditions and the following disclaimer in the 1511726Sascarpino * documentation and/or other materials provided with the distribution. 1611726Sascarpino * 4. Neither the name of the University nor the names of its contributors 1711726Sascarpino * may be used to endorse or promote products derived from this software 1811726Sascarpino * without specific prior written permission. 1911726Sascarpino * 2011726Sascarpino * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 2111726Sascarpino * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2211726Sascarpino * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2311726Sascarpino * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 2411726Sascarpino * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2511726Sascarpino * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2611726Sascarpino * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2711726Sascarpino * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2811726Sascarpino * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2911726Sascarpino * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3011726Sascarpino * SUCH DAMAGE. 3111726Sascarpino */ 3211726Sascarpino 3311726Sascarpino#if 0 3411726Sascarpino#ifndef lint 3511726Sascarpinostatic char const copyright[] = 3611726Sascarpino"@(#) Copyright (c) 1984, 1993\n\ 3711726Sascarpino The Regents of the University of California. All rights reserved.\n"; 3811726Sascarpino#endif /* not lint */ 3911726Sascarpino 4011726Sascarpino#ifndef lint 4111726Sascarpinostatic char const sccsid[] = "@(#)from: arp.c 8.2 (Berkeley) 1/2/94"; 4211726Sascarpino#endif /* not lint */ 4311726Sascarpino#endif 4411726Sascarpino#include <sys/cdefs.h> 4511726Sascarpino__FBSDID("$FreeBSD: head/usr.sbin/arp/arp.c 163305 2006-10-13 12:38:43Z glebius $"); 4611726Sascarpino 4711726Sascarpino/* 4811726Sascarpino * arp - display, set, and delete arp table entries 4911726Sascarpino */ 5011726Sascarpino 5111726Sascarpino 5211726Sascarpino#include <sys/param.h> 5311726Sascarpino#include <sys/file.h> 5411726Sascarpino#include <sys/socket.h> 5511726Sascarpino#include <sys/sockio.h> 5611726Sascarpino#include <sys/sysctl.h> 5711726Sascarpino#include <sys/ioctl.h> 5811726Sascarpino#include <sys/time.h> 5911726Sascarpino 6011726Sascarpino#include <net/if.h> 6111726Sascarpino#include <net/if_dl.h> 6211726Sascarpino#include <net/if_types.h> 6311726Sascarpino#include <net/route.h> 6411726Sascarpino#include <net/iso88025.h> 6511726Sascarpino 6611726Sascarpino#include <netinet/in.h> 6711726Sascarpino#include <netinet/if_ether.h> 6811726Sascarpino 6911726Sascarpino#include <arpa/inet.h> 7011726Sascarpino 7111726Sascarpino#include <ctype.h> 7211726Sascarpino#include <err.h> 7311726Sascarpino#include <errno.h> 7411726Sascarpino#include <netdb.h> 7511726Sascarpino#include <nlist.h> 7611726Sascarpino#include <paths.h> 7711726Sascarpino#include <stdio.h> 7811726Sascarpino#include <stdlib.h> 7911726Sascarpino#include <string.h> 8011726Sascarpino#include <strings.h> 8111726Sascarpino#include <unistd.h> 8211726Sascarpino 8311726Sascarpinotypedef void (action_fn)(struct sockaddr_dl *sdl, 8411726Sascarpino struct sockaddr_inarp *s_in, struct rt_msghdr *rtm); 8511726Sascarpino 8611726Sascarpinostatic int search(u_long addr, action_fn *action); 8711726Sascarpinostatic action_fn print_entry; 8811726Sascarpinostatic action_fn nuke_entry; 8911726Sascarpino 9011726Sascarpinostatic int delete(char *host, int do_proxy); 9111726Sascarpinostatic void usage(void); 9211726Sascarpinostatic int set(int argc, char **argv); 9311726Sascarpinostatic int get(char *host); 9411726Sascarpinostatic int file(char *name); 9511726Sascarpinostatic struct rt_msghdr *rtmsg(int cmd, 9611726Sascarpino struct sockaddr_inarp *dst, struct sockaddr_dl *sdl); 9711726Sascarpinostatic int get_ether_addr(in_addr_t ipaddr, struct ether_addr *hwaddr); 9811726Sascarpinostatic struct sockaddr_inarp *getaddr(char *host); 9911726Sascarpinostatic int valid_type(int type); 10011726Sascarpino 10111726Sascarpinostatic int nflag; /* no reverse dns lookups */ 10211726Sascarpinostatic char *rifname; 10311726Sascarpino 10411726Sascarpinostatic int expire_time, flags, doing_proxy, proxy_only; 10511726Sascarpino 10611726Sascarpino/* which function we're supposed to do */ 10711726Sascarpino#define F_GET 1 10811726Sascarpino#define F_SET 2 10911726Sascarpino#define F_FILESET 3 11011726Sascarpino#define F_REPLACE 4 11111726Sascarpino#define F_DELETE 5 11211726Sascarpino 11311726Sascarpino#define SETFUNC(f) { if (func) usage(); func = (f); } 11411726Sascarpino 11511726Sascarpinoint 11611726Sascarpinomain(int argc, char *argv[]) 11711726Sascarpino{ 11811726Sascarpino int ch, func = 0; 11911726Sascarpino int rtn = 0; 12011726Sascarpino int aflag = 0; /* do it for all entries */ 12111726Sascarpino 12211726Sascarpino while ((ch = getopt(argc, argv, "andfsSi:")) != -1) 12311726Sascarpino switch((char)ch) { 12411726Sascarpino case 'a': 12511726Sascarpino aflag = 1; 12611726Sascarpino break; 12711726Sascarpino case 'd': 12811726Sascarpino SETFUNC(F_DELETE); 12911726Sascarpino break; 13011726Sascarpino case 'n': 13111726Sascarpino nflag = 1; 13211726Sascarpino break; 13311726Sascarpino case 'S': 13411726Sascarpino SETFUNC(F_REPLACE); 13511726Sascarpino break; 13611726Sascarpino case 's': 13711726Sascarpino SETFUNC(F_SET); 13811726Sascarpino break; 13911726Sascarpino case 'f' : 14011726Sascarpino SETFUNC(F_FILESET); 14111726Sascarpino break; 14211726Sascarpino case 'i': 14311726Sascarpino rifname = optarg; 14411726Sascarpino break; 14511726Sascarpino case '?': 14611726Sascarpino default: 14711726Sascarpino usage(); 14811726Sascarpino } 14911726Sascarpino argc -= optind; 15011726Sascarpino argv += optind; 15111726Sascarpino 15211726Sascarpino if (!func) 15311726Sascarpino func = F_GET; 15411726Sascarpino if (rifname) { 15511726Sascarpino if (func != F_GET && !(func == F_DELETE && aflag)) 15611726Sascarpino errx(1, "-i not applicable to this operation"); 15711726Sascarpino if (if_nametoindex(rifname) == 0) { 15811726Sascarpino if (errno == ENXIO) 15911726Sascarpino errx(1, "interface %s does not exist", rifname); 16011726Sascarpino else 16111726Sascarpino err(1, "if_nametoindex(%s)", rifname); 16211726Sascarpino } 16311726Sascarpino } 16411726Sascarpino switch (func) { 16511726Sascarpino case F_GET: 16611726Sascarpino if (aflag) { 16711726Sascarpino if (argc != 0) 16811726Sascarpino usage(); 16911726Sascarpino search(0, print_entry); 17011726Sascarpino } else { 17111726Sascarpino if (argc != 1) 17211726Sascarpino usage(); 17311726Sascarpino rtn = get(argv[0]); 17411726Sascarpino } 17511726Sascarpino break; 17611726Sascarpino case F_SET: 17711726Sascarpino case F_REPLACE: 17811726Sascarpino if (argc < 2 || argc > 6) 17911726Sascarpino usage(); 18011726Sascarpino if (func == F_REPLACE) 18111726Sascarpino (void)delete(argv[0], 0); 18211726Sascarpino rtn = set(argc, argv) ? 1 : 0; 18311726Sascarpino break; 18411726Sascarpino case F_DELETE: 18511726Sascarpino if (aflag) { 18611726Sascarpino if (argc != 0) 18711726Sascarpino usage(); 18811726Sascarpino search(0, nuke_entry); 18911726Sascarpino } else { 19011726Sascarpino if (argc == 2 && strncmp(argv[1], "pub", 3) == 0) 19111726Sascarpino ch = SIN_PROXY; 19211726Sascarpino else if (argc == 1) 19311726Sascarpino ch = 0; 19411726Sascarpino else 19511726Sascarpino usage(); 19611726Sascarpino rtn = delete(argv[0], ch); 19711726Sascarpino } 19811726Sascarpino break; 19911726Sascarpino case F_FILESET: 20011726Sascarpino if (argc != 1) 20111726Sascarpino usage(); 20211726Sascarpino rtn = file(argv[0]); 20311726Sascarpino break; 20411726Sascarpino } 20511726Sascarpino 20611726Sascarpino return (rtn); 20711726Sascarpino} 20811726Sascarpino 20911726Sascarpino/* 21011726Sascarpino * Process a file to set standard arp entries 21111726Sascarpino */ 21211726Sascarpinostatic int 21311726Sascarpinofile(char *name) 21411726Sascarpino{ 21511726Sascarpino FILE *fp; 21611726Sascarpino int i, retval; 21711726Sascarpino char line[100], arg[5][50], *args[5], *p; 21811726Sascarpino 21911726Sascarpino if ((fp = fopen(name, "r")) == NULL) 22011726Sascarpino err(1, "cannot open %s", name); 22111726Sascarpino args[0] = &arg[0][0]; 22211726Sascarpino args[1] = &arg[1][0]; 22311726Sascarpino args[2] = &arg[2][0]; 22411726Sascarpino args[3] = &arg[3][0]; 22511726Sascarpino args[4] = &arg[4][0]; 22611726Sascarpino retval = 0; 22711726Sascarpino while(fgets(line, 100, fp) != NULL) { 22811726Sascarpino if ((p = strchr(line, '#')) != NULL) 22911726Sascarpino *p = '\0'; 23011726Sascarpino for (p = line; isblank(*p); p++); 23111726Sascarpino if (*p == '\n' || *p == '\0') 23211726Sascarpino continue; 23311726Sascarpino i = sscanf(p, "%49s %49s %49s %49s %49s", arg[0], arg[1], 23411726Sascarpino arg[2], arg[3], arg[4]); 23511726Sascarpino if (i < 2) { 23611726Sascarpino warnx("bad line: %s", line); 23711726Sascarpino retval = 1; 23811726Sascarpino continue; 23911726Sascarpino } 24011726Sascarpino if (set(i, args)) 24111726Sascarpino retval = 1; 24211726Sascarpino } 24311726Sascarpino fclose(fp); 24411726Sascarpino return (retval); 24511726Sascarpino} 24611726Sascarpino 24711726Sascarpino/* 24811726Sascarpino * Given a hostname, fills up a (static) struct sockaddr_inarp with 24911726Sascarpino * the address of the host and returns a pointer to the 25011726Sascarpino * structure. 25111726Sascarpino */ 25211726Sascarpinostatic struct sockaddr_inarp * 25311726Sascarpinogetaddr(char *host) 25411726Sascarpino{ 25511726Sascarpino struct hostent *hp; 25611726Sascarpino static struct sockaddr_inarp reply; 25711726Sascarpino 25811726Sascarpino bzero(&reply, sizeof(reply)); 25911726Sascarpino reply.sin_len = sizeof(reply); 26011726Sascarpino reply.sin_family = AF_INET; 26111726Sascarpino reply.sin_addr.s_addr = inet_addr(host); 26211726Sascarpino if (reply.sin_addr.s_addr == INADDR_NONE) { 26311726Sascarpino if (!(hp = gethostbyname(host))) { 26411726Sascarpino warnx("%s: %s", host, hstrerror(h_errno)); 26511726Sascarpino return (NULL); 26611726Sascarpino } 26711726Sascarpino bcopy((char *)hp->h_addr, (char *)&reply.sin_addr, 26811726Sascarpino sizeof reply.sin_addr); 26911726Sascarpino } 27011726Sascarpino return (&reply); 27111726Sascarpino} 27211726Sascarpino 27311726Sascarpino/* 27411726Sascarpino * Returns true if the type is a valid one for ARP. 27511726Sascarpino */ 27611726Sascarpinostatic int 27711726Sascarpinovalid_type(int type) 27811726Sascarpino{ 27911726Sascarpino 28011726Sascarpino switch (type) { 28111726Sascarpino case IFT_ETHER: 28211726Sascarpino case IFT_FDDI: 28311726Sascarpino case IFT_ISO88023: 28411726Sascarpino case IFT_ISO88024: 28511726Sascarpino case IFT_ISO88025: 28611726Sascarpino case IFT_L2VLAN: 28711726Sascarpino case IFT_BRIDGE: 28811726Sascarpino return (1); 28911726Sascarpino default: 29011726Sascarpino return (0); 29111726Sascarpino } 29211726Sascarpino} 29311726Sascarpino 29411726Sascarpino/* 29511726Sascarpino * Set an individual arp entry 29611726Sascarpino */ 29711726Sascarpinostatic int 29811726Sascarpinoset(int argc, char **argv) 29911726Sascarpino{ 30011726Sascarpino struct sockaddr_inarp *addr; 30111726Sascarpino struct sockaddr_inarp *dst; /* what are we looking for */ 30211726Sascarpino struct sockaddr_dl *sdl; 30311726Sascarpino struct rt_msghdr *rtm; 30411726Sascarpino struct ether_addr *ea; 30511726Sascarpino char *host = argv[0], *eaddr = argv[1]; 30611726Sascarpino struct sockaddr_dl sdl_m; 30711726Sascarpino 30811726Sascarpino argc -= 2; 30911726Sascarpino argv += 2; 31011726Sascarpino 31111726Sascarpino bzero(&sdl_m, sizeof(sdl_m)); 31211726Sascarpino sdl_m.sdl_len = sizeof(sdl_m); 31311726Sascarpino sdl_m.sdl_family = AF_LINK; 31411726Sascarpino 31511726Sascarpino dst = getaddr(host); 31611726Sascarpino if (dst == NULL) 31711726Sascarpino return (1); 31811726Sascarpino doing_proxy = flags = proxy_only = expire_time = 0; 31911726Sascarpino while (argc-- > 0) { 32011726Sascarpino if (strncmp(argv[0], "temp", 4) == 0) { 32111726Sascarpino struct timeval tv; 32211726Sascarpino gettimeofday(&tv, 0); 32311726Sascarpino expire_time = tv.tv_sec + 20 * 60; 32411726Sascarpino } 32511726Sascarpino else if (strncmp(argv[0], "pub", 3) == 0) { 32611726Sascarpino flags |= RTF_ANNOUNCE; 32711726Sascarpino doing_proxy = 1; 32811726Sascarpino if (argc && strncmp(argv[1], "only", 3) == 0) { 32911726Sascarpino proxy_only = 1; 33011726Sascarpino dst->sin_other = SIN_PROXY; 33111726Sascarpino argc--; argv++; 33211726Sascarpino } 33311726Sascarpino } else if (strncmp(argv[0], "trail", 5) == 0) { 33411726Sascarpino /* XXX deprecated and undocumented feature */ 33511726Sascarpino printf("%s: Sending trailers is no longer supported\n", 33611726Sascarpino host); 33711726Sascarpino } 33811726Sascarpino argv++; 33911726Sascarpino } 34011726Sascarpino ea = (struct ether_addr *)LLADDR(&sdl_m); 34111726Sascarpino if (doing_proxy && !strcmp(eaddr, "auto")) { 34211726Sascarpino if (!get_ether_addr(dst->sin_addr.s_addr, ea)) { 34311726Sascarpino printf("no interface found for %s\n", 34411726Sascarpino inet_ntoa(dst->sin_addr)); 34511726Sascarpino return (1); 34611726Sascarpino } 34711726Sascarpino sdl_m.sdl_alen = ETHER_ADDR_LEN; 34811726Sascarpino } else { 34911726Sascarpino struct ether_addr *ea1 = ether_aton(eaddr); 35011726Sascarpino 35111726Sascarpino if (ea1 == NULL) { 35211726Sascarpino warnx("invalid Ethernet address '%s'", eaddr); 35311726Sascarpino return (1); 35411726Sascarpino } else { 35511726Sascarpino *ea = *ea1; 35611726Sascarpino sdl_m.sdl_alen = ETHER_ADDR_LEN; 35711726Sascarpino } 35811726Sascarpino } 35911726Sascarpino for (;;) { /* try at most twice */ 36011726Sascarpino rtm = rtmsg(RTM_GET, dst, &sdl_m); 36111726Sascarpino if (rtm == NULL) { 36211726Sascarpino warn("%s", host); 36311726Sascarpino return (1); 36411726Sascarpino } 36511726Sascarpino addr = (struct sockaddr_inarp *)(rtm + 1); 36611726Sascarpino sdl = (struct sockaddr_dl *)(SA_SIZE(addr) + (char *)addr); 36711726Sascarpino if (addr->sin_addr.s_addr != dst->sin_addr.s_addr) 36811726Sascarpino break; 36911726Sascarpino if (sdl->sdl_family == AF_LINK && 37011726Sascarpino (rtm->rtm_flags & RTF_LLINFO) && 37111726Sascarpino !(rtm->rtm_flags & RTF_GATEWAY) && 37211726Sascarpino valid_type(sdl->sdl_type) ) 37311726Sascarpino break; 37411726Sascarpino if (doing_proxy == 0) { 37511726Sascarpino printf("set: can only proxy for %s\n", host); 37611726Sascarpino return (1); 37711726Sascarpino } 37811726Sascarpino if (dst->sin_other & SIN_PROXY) { 37911726Sascarpino printf("set: proxy entry exists for non 802 device\n"); 38011726Sascarpino return (1); 38111726Sascarpino } 38211726Sascarpino dst->sin_other = SIN_PROXY; 38311726Sascarpino proxy_only = 1; 38411726Sascarpino } 38511726Sascarpino 38611726Sascarpino if (sdl->sdl_family != AF_LINK) { 38711726Sascarpino printf("cannot intuit interface index and type for %s\n", host); 38811726Sascarpino return (1); 38911726Sascarpino } 39011726Sascarpino sdl_m.sdl_type = sdl->sdl_type; 39111726Sascarpino sdl_m.sdl_index = sdl->sdl_index; 39211726Sascarpino return (rtmsg(RTM_ADD, dst, &sdl_m) == NULL); 39311726Sascarpino} 39411726Sascarpino 39511726Sascarpino/* 39611726Sascarpino * Display an individual arp entry 39711726Sascarpino */ 39811726Sascarpinostatic int 39911726Sascarpinoget(char *host) 40011726Sascarpino{ 40111726Sascarpino struct sockaddr_inarp *addr; 40211726Sascarpino 40311726Sascarpino addr = getaddr(host); 40411726Sascarpino if (addr == NULL) 40511726Sascarpino return (1); 40611726Sascarpino if (0 == search(addr->sin_addr.s_addr, print_entry)) { 40711726Sascarpino printf("%s (%s) -- no entry", 40811726Sascarpino host, inet_ntoa(addr->sin_addr)); 40911726Sascarpino if (rifname) 41011726Sascarpino printf(" on %s", rifname); 41111726Sascarpino printf("\n"); 41211726Sascarpino return (1); 41311726Sascarpino } 41411726Sascarpino return (0); 41511726Sascarpino} 416 417/* 418 * Delete an arp entry 419 */ 420static int 421delete(char *host, int do_proxy) 422{ 423 struct sockaddr_inarp *addr, *dst; 424 struct rt_msghdr *rtm; 425 struct sockaddr_dl *sdl; 426 427 dst = getaddr(host); 428 if (dst == NULL) 429 return (1); 430 dst->sin_other = do_proxy; 431 for (;;) { /* try twice */ 432 rtm = rtmsg(RTM_GET, dst, NULL); 433 if (rtm == NULL) { 434 warn("%s", host); 435 return (1); 436 } 437 addr = (struct sockaddr_inarp *)(rtm + 1); 438 sdl = (struct sockaddr_dl *)(SA_SIZE(addr) + (char *)addr); 439 if (addr->sin_addr.s_addr == dst->sin_addr.s_addr && 440 sdl->sdl_family == AF_LINK && 441 (rtm->rtm_flags & RTF_LLINFO) && 442 !(rtm->rtm_flags & RTF_GATEWAY) && 443 valid_type(sdl->sdl_type) ) 444 break; /* found it */ 445 if (dst->sin_other & SIN_PROXY) { 446 fprintf(stderr, "delete: cannot locate %s\n",host); 447 return (1); 448 } 449 dst->sin_other = SIN_PROXY; 450 } 451 if (rtmsg(RTM_DELETE, dst, NULL) != NULL) { 452 printf("%s (%s) deleted\n", host, inet_ntoa(addr->sin_addr)); 453 return (0); 454 } 455 return (1); 456} 457 458/* 459 * Search the arp table and do some action on matching entries 460 */ 461static int 462search(u_long addr, action_fn *action) 463{ 464 int mib[6]; 465 size_t needed; 466 char *lim, *buf, *newbuf, *next; 467 struct rt_msghdr *rtm; 468 struct sockaddr_inarp *sin2; 469 struct sockaddr_dl *sdl; 470 char ifname[IF_NAMESIZE]; 471 int st, found_entry = 0; 472 473 mib[0] = CTL_NET; 474 mib[1] = PF_ROUTE; 475 mib[2] = 0; 476 mib[3] = AF_INET; 477 mib[4] = NET_RT_FLAGS; 478 mib[5] = RTF_LLINFO; 479 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) 480 err(1, "route-sysctl-estimate"); 481 if (needed == 0) /* empty table */ 482 return 0; 483 buf = NULL; 484 for (;;) { 485 newbuf = realloc(buf, needed); 486 if (newbuf == NULL) { 487 if (buf != NULL) 488 free(buf); 489 errx(1, "could not reallocate memory"); 490 } 491 buf = newbuf; 492 st = sysctl(mib, 6, buf, &needed, NULL, 0); 493 if (st == 0 || errno != ENOMEM) 494 break; 495 needed += needed / 8; 496 } 497 if (st == -1) 498 err(1, "actual retrieval of routing table"); 499 lim = buf + needed; 500 for (next = buf; next < lim; next += rtm->rtm_msglen) { 501 rtm = (struct rt_msghdr *)next; 502 sin2 = (struct sockaddr_inarp *)(rtm + 1); 503 sdl = (struct sockaddr_dl *)((char *)sin2 + SA_SIZE(sin2)); 504 if (rifname && if_indextoname(sdl->sdl_index, ifname) && 505 strcmp(ifname, rifname)) 506 continue; 507 if (addr) { 508 if (addr != sin2->sin_addr.s_addr) 509 continue; 510 found_entry = 1; 511 } 512 (*action)(sdl, sin2, rtm); 513 } 514 free(buf); 515 return (found_entry); 516} 517 518/* 519 * Display an arp entry 520 */ 521static void 522print_entry(struct sockaddr_dl *sdl, 523 struct sockaddr_inarp *addr, struct rt_msghdr *rtm) 524{ 525 const char *host; 526 struct hostent *hp; 527 struct iso88025_sockaddr_dl_data *trld; 528 char ifname[IF_NAMESIZE]; 529 int seg; 530 531 if (nflag == 0) 532 hp = gethostbyaddr((caddr_t)&(addr->sin_addr), 533 sizeof addr->sin_addr, AF_INET); 534 else 535 hp = 0; 536 if (hp) 537 host = hp->h_name; 538 else { 539 host = "?"; 540 if (h_errno == TRY_AGAIN) 541 nflag = 1; 542 } 543 printf("%s (%s) at ", host, inet_ntoa(addr->sin_addr)); 544 if (sdl->sdl_alen) { 545 if ((sdl->sdl_type == IFT_ETHER || 546 sdl->sdl_type == IFT_L2VLAN || 547 sdl->sdl_type == IFT_BRIDGE) && 548 sdl->sdl_alen == ETHER_ADDR_LEN) 549 printf("%s", ether_ntoa((struct ether_addr *)LLADDR(sdl))); 550 else { 551 int n = sdl->sdl_nlen > 0 ? sdl->sdl_nlen + 1 : 0; 552 553 printf("%s", link_ntoa(sdl) + n); 554 } 555 } else 556 printf("(incomplete)"); 557 if (if_indextoname(sdl->sdl_index, ifname) != NULL) 558 printf(" on %s", ifname); 559 if (rtm->rtm_rmx.rmx_expire == 0) 560 printf(" permanent"); 561 if (addr->sin_other & SIN_PROXY) 562 printf(" published (proxy only)"); 563 if (rtm->rtm_addrs & RTA_NETMASK) { 564 addr = (struct sockaddr_inarp *) 565 (SA_SIZE(sdl) + (char *)sdl); 566 if (addr->sin_addr.s_addr == 0xffffffff) 567 printf(" published"); 568 if (addr->sin_len != 8) 569 printf("(weird)"); 570 } 571 switch(sdl->sdl_type) { 572 case IFT_ETHER: 573 printf(" [ethernet]"); 574 break; 575 case IFT_ISO88025: 576 printf(" [token-ring]"); 577 trld = SDL_ISO88025(sdl); 578 if (trld->trld_rcf != 0) { 579 printf(" rt=%x", ntohs(trld->trld_rcf)); 580 for (seg = 0; 581 seg < ((TR_RCF_RIFLEN(trld->trld_rcf) - 2 ) / 2); 582 seg++) 583 printf(":%x", ntohs(*(trld->trld_route[seg]))); 584 } 585 break; 586 case IFT_FDDI: 587 printf(" [fddi]"); 588 break; 589 case IFT_ATM: 590 printf(" [atm]"); 591 break; 592 case IFT_L2VLAN: 593 printf(" [vlan]"); 594 break; 595 case IFT_IEEE1394: 596 printf(" [firewire]"); 597 break; 598 case IFT_BRIDGE: 599 printf(" [bridge]"); 600 break; 601 default: 602 break; 603 } 604 605 printf("\n"); 606 607} 608 609/* 610 * Nuke an arp entry 611 */ 612static void 613nuke_entry(struct sockaddr_dl *sdl __unused, 614 struct sockaddr_inarp *addr, struct rt_msghdr *rtm __unused) 615{ 616 char ip[20]; 617 618 snprintf(ip, sizeof(ip), "%s", inet_ntoa(addr->sin_addr)); 619 (void)delete(ip, 0); 620} 621 622static void 623usage(void) 624{ 625 fprintf(stderr, "%s\n%s\n%s\n%s\n%s\n%s\n%s\n", 626 "usage: arp [-n] [-i interface] hostname", 627 " arp [-n] [-i interface] -a", 628 " arp -d hostname [pub]", 629 " arp -d [-i interface] -a", 630 " arp -s hostname ether_addr [temp] [pub [only]]", 631 " arp -S hostname ether_addr [temp] [pub [only]]", 632 " arp -f filename"); 633 exit(1); 634} 635 636static struct rt_msghdr * 637rtmsg(int cmd, struct sockaddr_inarp *dst, struct sockaddr_dl *sdl) 638{ 639 static int seq; 640 int rlen; 641 int l; 642 struct sockaddr_in so_mask; 643 static int s = -1; 644 static pid_t pid; 645 646 static struct { 647 struct rt_msghdr m_rtm; 648 char m_space[512]; 649 } m_rtmsg; 650 651 struct rt_msghdr *rtm = &m_rtmsg.m_rtm; 652 char *cp = m_rtmsg.m_space; 653 654 if (s < 0) { /* first time: open socket, get pid */ 655 s = socket(PF_ROUTE, SOCK_RAW, 0); 656 if (s < 0) 657 err(1, "socket"); 658 pid = getpid(); 659 } 660 bzero(&so_mask, sizeof(so_mask)); 661 so_mask.sin_len = 8; 662 so_mask.sin_addr.s_addr = 0xffffffff; 663 664 errno = 0; 665 /* 666 * XXX RTM_DELETE relies on a previous RTM_GET to fill the buffer 667 * appropriately. 668 */ 669 if (cmd == RTM_DELETE) 670 goto doit; 671 bzero((char *)&m_rtmsg, sizeof(m_rtmsg)); 672 rtm->rtm_flags = flags; 673 rtm->rtm_version = RTM_VERSION; 674 675 switch (cmd) { 676 default: 677 errx(1, "internal wrong cmd"); 678 case RTM_ADD: 679 rtm->rtm_addrs |= RTA_GATEWAY; 680 rtm->rtm_rmx.rmx_expire = expire_time; 681 rtm->rtm_inits = RTV_EXPIRE; 682 rtm->rtm_flags |= (RTF_HOST | RTF_STATIC); 683 dst->sin_other = 0; 684 if (doing_proxy) { 685 if (proxy_only) 686 dst->sin_other = SIN_PROXY; 687 else { 688 rtm->rtm_addrs |= RTA_NETMASK; 689 rtm->rtm_flags &= ~RTF_HOST; 690 } 691 } 692 /* FALLTHROUGH */ 693 case RTM_GET: 694 rtm->rtm_addrs |= RTA_DST; 695 } 696#define NEXTADDR(w, s) \ 697 if ((s) != NULL && rtm->rtm_addrs & (w)) { \ 698 bcopy((s), cp, sizeof(*(s))); cp += SA_SIZE(s);} 699 700 NEXTADDR(RTA_DST, dst); 701 NEXTADDR(RTA_GATEWAY, sdl); 702 NEXTADDR(RTA_NETMASK, &so_mask); 703 704 rtm->rtm_msglen = cp - (char *)&m_rtmsg; 705doit: 706 l = rtm->rtm_msglen; 707 rtm->rtm_seq = ++seq; 708 rtm->rtm_type = cmd; 709 if ((rlen = write(s, (char *)&m_rtmsg, l)) < 0) { 710 if (errno != ESRCH || cmd != RTM_DELETE) { 711 warn("writing to routing socket"); 712 return (NULL); 713 } 714 } 715 do { 716 l = read(s, (char *)&m_rtmsg, sizeof(m_rtmsg)); 717 } while (l > 0 && (rtm->rtm_seq != seq || rtm->rtm_pid != pid)); 718 if (l < 0) 719 warn("read from routing socket"); 720 return (rtm); 721} 722 723/* 724 * get_ether_addr - get the hardware address of an interface on the 725 * the same subnet as ipaddr. 726 */ 727#define MAX_IFS 32 728 729static int 730get_ether_addr(in_addr_t ipaddr, struct ether_addr *hwaddr) 731{ 732 struct ifreq *ifr, *ifend, *ifp; 733 in_addr_t ina, mask; 734 struct sockaddr_dl *dla; 735 struct ifreq ifreq; 736 struct ifconf ifc; 737 struct ifreq ifs[MAX_IFS]; 738 int sock; 739 int retval = 0; 740 741 sock = socket(AF_INET, SOCK_DGRAM, 0); 742 if (sock < 0) 743 err(1, "socket"); 744 745 ifc.ifc_len = sizeof(ifs); 746 ifc.ifc_req = ifs; 747 if (ioctl(sock, SIOCGIFCONF, &ifc) < 0) { 748 warnx("ioctl(SIOCGIFCONF)"); 749 goto done; 750 } 751 752#define NEXTIFR(i) \ 753 ((struct ifreq *)((char *)&(i)->ifr_addr \ 754 + MAX((i)->ifr_addr.sa_len, sizeof((i)->ifr_addr))) ) 755 756 /* 757 * Scan through looking for an interface with an Internet 758 * address on the same subnet as `ipaddr'. 759 */ 760 ifend = (struct ifreq *)(ifc.ifc_buf + ifc.ifc_len); 761 for (ifr = ifc.ifc_req; ifr < ifend; ifr = NEXTIFR(ifr) ) { 762 if (ifr->ifr_addr.sa_family != AF_INET) 763 continue; 764 strncpy(ifreq.ifr_name, ifr->ifr_name, 765 sizeof(ifreq.ifr_name)); 766 ifreq.ifr_addr = ifr->ifr_addr; 767 /* 768 * Check that the interface is up, 769 * and not point-to-point or loopback. 770 */ 771 if (ioctl(sock, SIOCGIFFLAGS, &ifreq) < 0) 772 continue; 773 if ((ifreq.ifr_flags & 774 (IFF_UP|IFF_BROADCAST|IFF_POINTOPOINT| 775 IFF_LOOPBACK|IFF_NOARP)) 776 != (IFF_UP|IFF_BROADCAST)) 777 continue; 778 /* 779 * Get its netmask and check that it's on 780 * the right subnet. 781 */ 782 if (ioctl(sock, SIOCGIFNETMASK, &ifreq) < 0) 783 continue; 784 mask = ((struct sockaddr_in *) 785 &ifreq.ifr_addr)->sin_addr.s_addr; 786 ina = ((struct sockaddr_in *) 787 &ifr->ifr_addr)->sin_addr.s_addr; 788 if ((ipaddr & mask) == (ina & mask)) 789 break; /* ok, we got it! */ 790 } 791 792 if (ifr >= ifend) 793 goto done; 794 795 /* 796 * Now scan through again looking for a link-level address 797 * for this interface. 798 */ 799 ifp = ifr; 800 for (ifr = ifc.ifc_req; ifr < ifend; ifr = NEXTIFR(ifr)) 801 if (strcmp(ifp->ifr_name, ifr->ifr_name) == 0 && 802 ifr->ifr_addr.sa_family == AF_LINK) 803 break; 804 if (ifr >= ifend) 805 goto done; 806 /* 807 * Found the link-level address - copy it out 808 */ 809 dla = (struct sockaddr_dl *) &ifr->ifr_addr; 810 memcpy(hwaddr, LLADDR(dla), dla->sdl_alen); 811 printf("using interface %s for proxy with address ", 812 ifp->ifr_name); 813 printf("%s\n", ether_ntoa(hwaddr)); 814 retval = dla->sdl_alen; 815done: 816 close(sock); 817 return (retval); 818} 819