1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
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 #if 0
36 #ifndef lint
37 static char const copyright[] =
38 "@(#) Copyright (c) 1984, 1993\n\
39 The Regents of the University of California. All rights reserved.\n";
40 #endif /* not lint */
41
42 #ifndef lint
43 static char const sccsid[] = "@(#)from: arp.c 8.2 (Berkeley) 1/2/94";
44 #endif /* not lint */
45 #endif
46 #include <sys/cdefs.h>
47 __FBSDID("$FreeBSD$");
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/sockio.h>
57 #include <sys/sysctl.h>
58 #include <sys/ioctl.h>
59 #include <sys/time.h>
60
61 #include <net/if.h>
62 #include <net/if_dl.h>
63 #include <net/if_types.h>
64 #include <net/route.h>
65
66 #include <netinet/in.h>
67 #include <netinet/if_ether.h>
68
69 #include <arpa/inet.h>
70
71 #include <ctype.h>
72 #include <err.h>
73 #include <errno.h>
74 #include <netdb.h>
75 #include <nlist.h>
76 #include <paths.h>
77 #include <stdio.h>
78 #include <stdlib.h>
79 #include <string.h>
80 #include <strings.h>
81 #include <unistd.h>
82 #include <libxo/xo.h>
83
84 #ifdef FSTACK
85 #include <time.h>
86 #include "rtioctl.h"
87 #include "ff_ipc.h"
88
89 #ifndef __unused
90 #define __unused __attribute__((__unused__))
91
92 #define socket(a, b, c) rt_socket((a), (b), (c))
93 #define close(a) rt_close(a)
94
95 #endif
96
97 #endif
98
99 typedef void (action_fn)(struct sockaddr_dl *sdl, struct sockaddr_in *s_in,
100 struct rt_msghdr *rtm);
101
102 static int search(u_long addr, action_fn *action);
103 static action_fn print_entry;
104 static action_fn nuke_entry;
105
106 static int delete(char *host);
107 static void usage(void);
108 static int set(int argc, char **argv);
109 static int get(char *host);
110 static int file(char *name);
111 static struct rt_msghdr *rtmsg(int cmd,
112 struct sockaddr_in *dst, struct sockaddr_dl *sdl);
113 static int get_ether_addr(in_addr_t ipaddr, struct ether_addr *hwaddr);
114 static struct sockaddr_in *getaddr(char *host);
115 static int valid_type(int type);
116
117 static int nflag; /* no reverse dns lookups */
118 static char *rifname;
119
120 static time_t expire_time;
121 static int flags, doing_proxy;
122
123 struct if_nameindex *ifnameindex;
124
125 /* which function we're supposed to do */
126 #define F_GET 1
127 #define F_SET 2
128 #define F_FILESET 3
129 #define F_REPLACE 4
130 #define F_DELETE 5
131
132 #define SETFUNC(f) { if (func) usage(); func = (f); }
133
134 #define ARP_XO_VERSION "1"
135
136 int
main(int argc,char * argv[])137 main(int argc, char *argv[])
138 {
139 int ch, func = 0;
140 int rtn = 0;
141 int aflag = 0; /* do it for all entries */
142
143 argc = xo_parse_args(argc, argv);
144 if (argc < 0)
145 exit(1);
146
147 #ifndef FSTACK
148 while ((ch = getopt(argc, argv, "andfsSi:")) != -1)
149 #else
150 ff_ipc_init();
151 while ((ch = getopt(argc, argv, "andfsSi:p:")) != -1)
152 #endif
153 switch(ch) {
154 case 'a':
155 aflag = 1;
156 break;
157 case 'd':
158 SETFUNC(F_DELETE);
159 break;
160 case 'n':
161 nflag = 1;
162 break;
163 case 'S':
164 SETFUNC(F_REPLACE);
165 break;
166 case 's':
167 SETFUNC(F_SET);
168 break;
169 case 'f' :
170 SETFUNC(F_FILESET);
171 break;
172 case 'i':
173 rifname = optarg;
174 break;
175 #ifdef FSTACK
176 case 'p':
177 ff_set_proc_id(atoi(optarg));
178 break;
179 #endif
180 case '?':
181 default:
182 usage();
183 }
184 argc -= optind;
185 argv += optind;
186
187 if (!func)
188 func = F_GET;
189 if (rifname) {
190 if (func != F_GET && !(func == F_DELETE && aflag))
191 xo_errx(1, "-i not applicable to this operation");
192 if (if_nametoindex(rifname) == 0) {
193 if (errno == ENXIO)
194 xo_errx(1, "interface %s does not exist",
195 rifname);
196 else
197 xo_err(1, "if_nametoindex(%s)", rifname);
198 }
199 }
200 switch (func) {
201 case F_GET:
202 if (aflag) {
203 if (argc != 0)
204 usage();
205
206 xo_set_version(ARP_XO_VERSION);
207 xo_open_container("arp");
208 xo_open_list("arp-cache");
209
210 search(0, print_entry);
211
212 xo_close_list("arp-cache");
213 xo_close_container("arp");
214 xo_finish();
215 } else {
216 if (argc != 1)
217 usage();
218 rtn = get(argv[0]);
219 }
220 break;
221 case F_SET:
222 case F_REPLACE:
223 if (argc < 2 || argc > 6)
224 usage();
225 if (func == F_REPLACE)
226 (void)delete(argv[0]);
227 rtn = set(argc, argv) ? 1 : 0;
228 break;
229 case F_DELETE:
230 if (aflag) {
231 if (argc != 0)
232 usage();
233 search(0, nuke_entry);
234 } else {
235 if (argc != 1)
236 usage();
237 rtn = delete(argv[0]);
238 }
239 break;
240 case F_FILESET:
241 if (argc != 1)
242 usage();
243 rtn = file(argv[0]);
244 break;
245 }
246
247 if (ifnameindex != NULL)
248 if_freenameindex(ifnameindex);
249
250 #ifdef FSTACK
251 ff_ipc_exit();
252 #endif
253
254 return (rtn);
255 }
256
257 /*
258 * Process a file to set standard arp entries
259 */
260 static int
file(char * name)261 file(char *name)
262 {
263 FILE *fp;
264 int i, retval;
265 char line[100], arg[5][50], *args[5], *p;
266
267 if ((fp = fopen(name, "r")) == NULL)
268 xo_err(1, "cannot open %s", name);
269 args[0] = &arg[0][0];
270 args[1] = &arg[1][0];
271 args[2] = &arg[2][0];
272 args[3] = &arg[3][0];
273 args[4] = &arg[4][0];
274 retval = 0;
275 while(fgets(line, sizeof(line), fp) != NULL) {
276 if ((p = strchr(line, '#')) != NULL)
277 *p = '\0';
278 for (p = line; isblank(*p); p++);
279 if (*p == '\n' || *p == '\0')
280 continue;
281 i = sscanf(p, "%49s %49s %49s %49s %49s", arg[0], arg[1],
282 arg[2], arg[3], arg[4]);
283 if (i < 2) {
284 xo_warnx("bad line: %s", line);
285 retval = 1;
286 continue;
287 }
288 if (set(i, args))
289 retval = 1;
290 }
291 fclose(fp);
292 return (retval);
293 }
294
295 /*
296 * Given a hostname, fills up a (static) struct sockaddr_in with
297 * the address of the host and returns a pointer to the
298 * structure.
299 */
300 static struct sockaddr_in *
getaddr(char * host)301 getaddr(char *host)
302 {
303 #ifndef FSTACK
304 struct hostent *hp;
305 #endif
306 static struct sockaddr_in reply;
307
308 bzero(&reply, sizeof(reply));
309 reply.sin_len = sizeof(reply);
310 reply.sin_family = AF_INET;
311 reply.sin_addr.s_addr = inet_addr(host);
312 if (reply.sin_addr.s_addr == INADDR_NONE) {
313 #ifndef FSTACK
314 if (!(hp = gethostbyname(host))) {
315 xo_warnx("%s: %s", host, hstrerror(h_errno));
316 return (NULL);
317 }
318 bcopy((char *)hp->h_addr, (char *)&reply.sin_addr,
319 sizeof reply.sin_addr);
320 #else
321 warnx("reply.sin_addr.s_addr == INADDR_NONE");
322 #endif
323 }
324 return (&reply);
325 }
326
327 /*
328 * Returns true if the type is a valid one for ARP.
329 */
330 static int
valid_type(int type)331 valid_type(int type)
332 {
333
334 switch (type) {
335 case IFT_ETHER:
336 case IFT_FDDI:
337 case IFT_INFINIBAND:
338 case IFT_ISO88023:
339 case IFT_ISO88024:
340 case IFT_L2VLAN:
341 case IFT_BRIDGE:
342 return (1);
343 default:
344 return (0);
345 }
346 }
347
348 /*
349 * Set an individual arp entry
350 */
351 static int
set(int argc,char ** argv)352 set(int argc, char **argv)
353 {
354 struct sockaddr_in *addr;
355 struct sockaddr_in *dst; /* what are we looking for */
356 struct sockaddr_dl *sdl;
357 struct rt_msghdr *rtm;
358 struct ether_addr *ea;
359 char *host = argv[0], *eaddr = argv[1];
360 struct sockaddr_dl sdl_m;
361
362 argc -= 2;
363 argv += 2;
364
365 bzero(&sdl_m, sizeof(sdl_m));
366 sdl_m.sdl_len = sizeof(sdl_m);
367 sdl_m.sdl_family = AF_LINK;
368
369 dst = getaddr(host);
370 if (dst == NULL)
371 return (1);
372 doing_proxy = flags = expire_time = 0;
373 while (argc-- > 0) {
374 if (strcmp(argv[0], "temp") == 0) {
375 struct timespec tp;
376 int max_age;
377 size_t len = sizeof(max_age);
378
379 clock_gettime(CLOCK_MONOTONIC, &tp);
380 if (sysctlbyname("net.link.ether.inet.max_age",
381 &max_age, &len, NULL, 0) != 0)
382 xo_err(1, "sysctlbyname");
383 expire_time = tp.tv_sec + max_age;
384 } else if (strcmp(argv[0], "pub") == 0) {
385 flags |= RTF_ANNOUNCE;
386 doing_proxy = 1;
387 if (argc && strcmp(argv[1], "only") == 0) {
388 /*
389 * Compatibility: in pre FreeBSD 8 times
390 * the "only" keyword used to mean that
391 * an ARP entry should be announced, but
392 * not installed into routing table.
393 */
394 argc--; argv++;
395 }
396 } else if (strcmp(argv[0], "blackhole") == 0) {
397 if (flags & RTF_REJECT) {
398 xo_errx(1, "Choose one of blackhole or reject, "
399 "not both.");
400 }
401 flags |= RTF_BLACKHOLE;
402 } else if (strcmp(argv[0], "reject") == 0) {
403 if (flags & RTF_BLACKHOLE) {
404 xo_errx(1, "Choose one of blackhole or reject, "
405 "not both.");
406 }
407 flags |= RTF_REJECT;
408 } else {
409 xo_warnx("Invalid parameter '%s'", argv[0]);
410 usage();
411 }
412 argv++;
413 }
414 ea = (struct ether_addr *)LLADDR(&sdl_m);
415 if (doing_proxy && !strcmp(eaddr, "auto")) {
416 if (!get_ether_addr(dst->sin_addr.s_addr, ea)) {
417 xo_warnx("no interface found for %s",
418 inet_ntoa(dst->sin_addr));
419 return (1);
420 }
421 sdl_m.sdl_alen = ETHER_ADDR_LEN;
422 } else {
423 struct ether_addr *ea1 = ether_aton(eaddr);
424
425 if (ea1 == NULL) {
426 xo_warnx("invalid Ethernet address '%s'", eaddr);
427 return (1);
428 } else {
429 *ea = *ea1;
430 sdl_m.sdl_alen = ETHER_ADDR_LEN;
431 }
432 }
433
434 /*
435 * In the case a proxy-arp entry is being added for
436 * a remote end point, the RTF_ANNOUNCE flag in the
437 * RTM_GET command is an indication to the kernel
438 * routing code that the interface associated with
439 * the prefix route covering the local end of the
440 * PPP link should be returned, on which ARP applies.
441 */
442 rtm = rtmsg(RTM_GET, dst, NULL);
443 if (rtm == NULL) {
444 xo_warn("%s", host);
445 return (1);
446 }
447 addr = (struct sockaddr_in *)(rtm + 1);
448 sdl = (struct sockaddr_dl *)(SA_SIZE(addr) + (char *)addr);
449
450 if ((sdl->sdl_family != AF_LINK) ||
451 (rtm->rtm_flags & RTF_GATEWAY) ||
452 !valid_type(sdl->sdl_type)) {
453 xo_warnx("cannot intuit interface index and type for %s", host);
454 return (1);
455 }
456 sdl_m.sdl_type = sdl->sdl_type;
457 sdl_m.sdl_index = sdl->sdl_index;
458 return (rtmsg(RTM_ADD, dst, &sdl_m) == NULL);
459 }
460
461 /*
462 * Display an individual arp entry
463 */
464 static int
get(char * host)465 get(char *host)
466 {
467 struct sockaddr_in *addr;
468 int found;
469
470 addr = getaddr(host);
471 if (addr == NULL)
472 return (1);
473
474 xo_set_version(ARP_XO_VERSION);
475 xo_open_container("arp");
476 xo_open_list("arp-cache");
477
478 found = search(addr->sin_addr.s_addr, print_entry);
479
480 if (found == 0) {
481 xo_emit("{d:hostname/%s} ({d:ip-address/%s}) -- no entry",
482 host, inet_ntoa(addr->sin_addr));
483 if (rifname)
484 xo_emit(" on {d:interface/%s}", rifname);
485 xo_emit("\n");
486 }
487
488 xo_close_list("arp-cache");
489 xo_close_container("arp");
490 xo_finish();
491
492 return (found == 0);
493 }
494
495 /*
496 * Delete an arp entry
497 */
498 static int
delete(char * host)499 delete(char *host)
500 {
501 struct sockaddr_in *addr, *dst;
502 struct rt_msghdr *rtm;
503 struct sockaddr_dl *sdl;
504
505 dst = getaddr(host);
506 if (dst == NULL)
507 return (1);
508
509 /*
510 * Perform a regular entry delete first.
511 */
512 flags &= ~RTF_ANNOUNCE;
513
514 for (;;) { /* try twice */
515 rtm = rtmsg(RTM_GET, dst, NULL);
516 if (rtm == NULL) {
517 xo_warn("%s", host);
518 return (1);
519 }
520 addr = (struct sockaddr_in *)(rtm + 1);
521 sdl = (struct sockaddr_dl *)(SA_SIZE(addr) + (char *)addr);
522
523 /*
524 * With the new L2/L3 restructure, the route
525 * returned is a prefix route. The important
526 * piece of information from the previous
527 * RTM_GET is the interface index. In the
528 * case of ECMP, the kernel will traverse
529 * the route group for the given entry.
530 */
531 if (sdl->sdl_family == AF_LINK &&
532 !(rtm->rtm_flags & RTF_GATEWAY) &&
533 valid_type(sdl->sdl_type) ) {
534 addr->sin_addr.s_addr = dst->sin_addr.s_addr;
535 break;
536 }
537
538 /*
539 * Regular entry delete failed, now check if there
540 * is a proxy-arp entry to remove.
541 */
542 if (flags & RTF_ANNOUNCE) {
543 xo_warnx("delete: cannot locate %s", host);
544 return (1);
545 }
546
547 flags |= RTF_ANNOUNCE;
548 }
549 rtm->rtm_flags |= RTF_LLDATA;
550 if (rtmsg(RTM_DELETE, dst, NULL) != NULL) {
551 printf("%s (%s) deleted\n", host, inet_ntoa(addr->sin_addr));
552 return (0);
553 }
554 return (1);
555 }
556
557
558 /*
559 * Search the arp table and do some action on matching entries
560 */
561 static int
search(u_long addr,action_fn * action)562 search(u_long addr, action_fn *action)
563 {
564 int mib[6];
565 size_t needed;
566 char *lim, *buf, *next;
567 struct rt_msghdr *rtm;
568 struct sockaddr_in *sin2;
569 struct sockaddr_dl *sdl;
570 char ifname[IF_NAMESIZE];
571 int st, found_entry = 0;
572
573 mib[0] = CTL_NET;
574 mib[1] = PF_ROUTE;
575 mib[2] = 0;
576 mib[3] = AF_INET;
577 mib[4] = NET_RT_FLAGS;
578 #ifdef RTF_LLINFO
579 mib[5] = RTF_LLINFO;
580 #else
581 mib[5] = 0;
582 #endif
583 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
584 xo_err(1, "route-sysctl-estimate");
585 if (needed == 0) /* empty table */
586 return 0;
587 buf = NULL;
588 for (;;) {
589 buf = reallocf(buf, needed);
590 if (buf == NULL)
591 xo_errx(1, "could not reallocate memory");
592 st = sysctl(mib, 6, buf, &needed, NULL, 0);
593 if (st == 0 || errno != ENOMEM)
594 break;
595 needed += needed / 8;
596 }
597 if (st == -1)
598 xo_err(1, "actual retrieval of routing table");
599 lim = buf + needed;
600 for (next = buf; next < lim; next += rtm->rtm_msglen) {
601 rtm = (struct rt_msghdr *)next;
602 sin2 = (struct sockaddr_in *)(rtm + 1);
603 sdl = (struct sockaddr_dl *)((char *)sin2 + SA_SIZE(sin2));
604 if (rifname && if_indextoname(sdl->sdl_index, ifname) &&
605 strcmp(ifname, rifname))
606 continue;
607 if (addr) {
608 if (addr != sin2->sin_addr.s_addr)
609 continue;
610 found_entry = 1;
611 }
612 (*action)(sdl, sin2, rtm);
613 }
614 free(buf);
615 return (found_entry);
616 }
617
618 /*
619 * Display an arp entry
620 */
621
622 static void
print_entry(struct sockaddr_dl * sdl,struct sockaddr_in * addr,struct rt_msghdr * rtm)623 print_entry(struct sockaddr_dl *sdl,
624 struct sockaddr_in *addr, struct rt_msghdr *rtm)
625 {
626 const char *host;
627 struct hostent *hp;
628 struct if_nameindex *p;
629
630 if (ifnameindex == NULL)
631 if ((ifnameindex = if_nameindex()) == NULL)
632 xo_err(1, "cannot retrieve interface names");
633
634 xo_open_instance("arp-cache");
635
636 if (nflag == 0)
637 hp = gethostbyaddr((caddr_t)&(addr->sin_addr),
638 sizeof addr->sin_addr, AF_INET);
639 else
640 hp = 0;
641 if (hp)
642 host = hp->h_name;
643 else {
644 host = "?";
645 if (h_errno == TRY_AGAIN)
646 nflag = 1;
647 }
648 xo_emit("{:hostname/%s} ({:ip-address/%s}) at ", host,
649 inet_ntoa(addr->sin_addr));
650 if (sdl->sdl_alen) {
651 if ((sdl->sdl_type == IFT_ETHER ||
652 sdl->sdl_type == IFT_L2VLAN ||
653 sdl->sdl_type == IFT_BRIDGE) &&
654 sdl->sdl_alen == ETHER_ADDR_LEN)
655 xo_emit("{:mac-address/%s}",
656 ether_ntoa((struct ether_addr *)LLADDR(sdl)));
657 else {
658 int n = sdl->sdl_nlen > 0 ? sdl->sdl_nlen + 1 : 0;
659
660 xo_emit("{:mac-address/%s}", link_ntoa(sdl) + n);
661 }
662 } else
663 xo_emit("{d:/(incomplete)}{en:incomplete/true}");
664
665 for (p = ifnameindex; p && p->if_index && p->if_name; p++) {
666 if (p->if_index == sdl->sdl_index) {
667 xo_emit(" on {:interface/%s}", p->if_name);
668 break;
669 }
670 }
671
672 if (rtm->rtm_rmx.rmx_expire == 0)
673 xo_emit("{d:/ permanent}{en:permanent/true}");
674 else {
675 static struct timespec tp;
676 if (tp.tv_sec == 0)
677 clock_gettime(CLOCK_MONOTONIC, &tp);
678 if ((expire_time = rtm->rtm_rmx.rmx_expire - tp.tv_sec) > 0)
679 xo_emit(" expires in {:expires/%d} seconds",
680 (int)expire_time);
681 else
682 xo_emit("{d:/ expired}{en:expired/true}");
683 }
684
685 if (rtm->rtm_flags & RTF_ANNOUNCE)
686 xo_emit("{d:/ published}{en:published/true}");
687
688 switch(sdl->sdl_type) {
689 case IFT_ETHER:
690 xo_emit(" [{:type/ethernet}]");
691 break;
692 case IFT_FDDI:
693 xo_emit(" [{:type/fddi}]");
694 break;
695 case IFT_ATM:
696 xo_emit(" [{:type/atm}]");
697 break;
698 case IFT_L2VLAN:
699 xo_emit(" [{:type/vlan}]");
700 break;
701 case IFT_IEEE1394:
702 xo_emit(" [{:type/firewire}]");
703 break;
704 case IFT_BRIDGE:
705 xo_emit(" [{:type/bridge}]");
706 break;
707 case IFT_INFINIBAND:
708 xo_emit(" [{:type/infiniband}]");
709 break;
710 default:
711 break;
712 }
713
714 xo_emit("\n");
715
716 xo_close_instance("arp-cache");
717 }
718
719 /*
720 * Nuke an arp entry
721 */
722 static void
nuke_entry(struct sockaddr_dl * sdl __unused,struct sockaddr_in * addr,struct rt_msghdr * rtm)723 nuke_entry(struct sockaddr_dl *sdl __unused,
724 struct sockaddr_in *addr, struct rt_msghdr *rtm)
725 {
726 char ip[20];
727
728 if (rtm->rtm_flags & RTF_PINNED)
729 return;
730
731 snprintf(ip, sizeof(ip), "%s", inet_ntoa(addr->sin_addr));
732 delete(ip);
733 }
734
735 static void
usage(void)736 usage(void)
737 {
738 fprintf(stderr, "%s\n%s\n%s\n%s\n%s\n%s\n%s\n",
739 #ifndef FSTACK
740 "usage: arp [-n] [-i interface] hostname",
741 " arp [-n] [-i interface] -a",
742 " arp -d hostname [pub]",
743 " arp -d [-i interface] -a",
744 " arp -s hostname ether_addr [temp] [reject | blackhole] [pub [only]]",
745 " arp -S hostname ether_addr [temp] [reject | blackhole] [pub [only]]",
746 " arp -f filename");
747 #else
748 "usage: arp -p <f-stack proc_id> [-n] [-i interface] hostname",
749 " arp -p <f-stack proc_id> [-n] [-i interface] -a",
750 " arp -p <f-stack proc_id> -d hostname [pub]",
751 " arp -p <f-stack proc_id> -d [-i interface] -a",
752 " arp -p <f-stack proc_id> -s hostname ether_addr [temp] [reject | blackhole] [pub [only]]",
753 " arp -p <f-stack proc_id> -S hostname ether_addr [temp] [reject | blackhole] [pub [only]]",
754 " arp -p <f-stack proc_id> -f filename");
755 #endif
756 #ifdef FSTACK
757 ff_ipc_exit();
758 #endif
759
760 exit(1);
761 }
762
763 static struct rt_msghdr *
rtmsg(int cmd,struct sockaddr_in * dst,struct sockaddr_dl * sdl)764 rtmsg(int cmd, struct sockaddr_in *dst, struct sockaddr_dl *sdl)
765 {
766 static int seq;
767 int rlen;
768 int l;
769 static int s = -1;
770 static pid_t pid;
771
772 static struct {
773 struct rt_msghdr m_rtm;
774 char m_space[512];
775 } m_rtmsg;
776
777 struct rt_msghdr *rtm = &m_rtmsg.m_rtm;
778 char *cp = m_rtmsg.m_space;
779
780 if (s < 0) { /* first time: open socket, get pid */
781 s = socket(PF_ROUTE, SOCK_RAW, 0);
782 if (s < 0)
783 xo_err(1, "socket");
784 pid = getpid();
785 }
786
787 errno = 0;
788 /*
789 * XXX RTM_DELETE relies on a previous RTM_GET to fill the buffer
790 * appropriately.
791 */
792 if (cmd == RTM_DELETE)
793 goto doit;
794 bzero((char *)&m_rtmsg, sizeof(m_rtmsg));
795 rtm->rtm_flags = flags;
796 rtm->rtm_version = RTM_VERSION;
797
798 switch (cmd) {
799 default:
800 xo_errx(1, "internal wrong cmd");
801 case RTM_ADD:
802 rtm->rtm_addrs |= RTA_GATEWAY;
803 rtm->rtm_rmx.rmx_expire = expire_time;
804 rtm->rtm_inits = RTV_EXPIRE;
805 rtm->rtm_flags |= (RTF_HOST | RTF_STATIC | RTF_LLDATA);
806 /* FALLTHROUGH */
807 case RTM_GET:
808 rtm->rtm_addrs |= RTA_DST;
809 }
810 #define NEXTADDR(w, s) \
811 do { \
812 if ((s) != NULL && rtm->rtm_addrs & (w)) { \
813 bcopy((s), cp, sizeof(*(s))); \
814 cp += SA_SIZE(s); \
815 } \
816 } while (0)
817
818 NEXTADDR(RTA_DST, dst);
819 NEXTADDR(RTA_GATEWAY, sdl);
820
821 rtm->rtm_msglen = cp - (char *)&m_rtmsg;
822 doit:
823 l = rtm->rtm_msglen;
824 rtm->rtm_seq = ++seq;
825 rtm->rtm_type = cmd;
826 #ifndef FSTACK
827 if ((rlen = write(s, (char *)&m_rtmsg, l)) < 0) {
828 if (errno != ESRCH || cmd != RTM_DELETE) {
829 xo_warn("writing to routing socket");
830 return (NULL);
831 }
832 }
833 do {
834 l = read(s, (char *)&m_rtmsg, sizeof(m_rtmsg));
835 } while (l > 0 && (rtm->rtm_type != cmd || rtm->rtm_seq != seq ||
836 rtm->rtm_pid != pid));
837 #else
838 l = rtioctl((char *)&m_rtmsg, l, sizeof(m_rtmsg));
839 #endif
840 if (l < 0)
841 xo_warn("read from routing socket");
842 return (rtm);
843 }
844
845 /*
846 * get_ether_addr - get the hardware address of an interface on the
847 * the same subnet as ipaddr.
848 */
849 #define MAX_IFS 32
850
851 static int
get_ether_addr(in_addr_t ipaddr,struct ether_addr * hwaddr)852 get_ether_addr(in_addr_t ipaddr, struct ether_addr *hwaddr)
853 {
854 struct ifreq *ifr, *ifend, *ifp;
855 in_addr_t ina, mask;
856 struct sockaddr_dl *dla;
857 struct ifreq ifreq;
858 struct ifconf ifc;
859 struct ifreq ifs[MAX_IFS];
860 int sock;
861 int retval = 0;
862
863 sock = socket(AF_INET, SOCK_DGRAM, 0);
864 if (sock < 0)
865 xo_err(1, "socket");
866
867 ifc.ifc_len = sizeof(ifs);
868 ifc.ifc_req = ifs;
869 if (ioctl(sock, SIOCGIFCONF, &ifc) < 0) {
870 xo_warnx("ioctl(SIOCGIFCONF)");
871 goto done;
872 }
873
874 #define NEXTIFR(i) \
875 ((struct ifreq *)((char *)&(i)->ifr_addr \
876 + MAX((i)->ifr_addr.sa_len, sizeof((i)->ifr_addr))) )
877
878 /*
879 * Scan through looking for an interface with an Internet
880 * address on the same subnet as `ipaddr'.
881 */
882 ifend = (struct ifreq *)(ifc.ifc_buf + ifc.ifc_len);
883 for (ifr = ifc.ifc_req; ifr < ifend; ifr = NEXTIFR(ifr) ) {
884 if (ifr->ifr_addr.sa_family != AF_INET)
885 continue;
886 strncpy(ifreq.ifr_name, ifr->ifr_name,
887 sizeof(ifreq.ifr_name));
888 ifreq.ifr_addr = ifr->ifr_addr;
889 /*
890 * Check that the interface is up,
891 * and not point-to-point or loopback.
892 */
893 if (ioctl(sock, SIOCGIFFLAGS, &ifreq) < 0)
894 continue;
895 if ((ifreq.ifr_flags &
896 (IFF_UP|IFF_BROADCAST|IFF_POINTOPOINT|
897 IFF_LOOPBACK|IFF_NOARP)) != (IFF_UP|IFF_BROADCAST))
898 continue;
899 /* Get its netmask and check that it's on the right subnet. */
900 if (ioctl(sock, SIOCGIFNETMASK, &ifreq) < 0)
901 continue;
902 mask = ((struct sockaddr_in *)
903 &ifreq.ifr_addr)->sin_addr.s_addr;
904 ina = ((struct sockaddr_in *)
905 &ifr->ifr_addr)->sin_addr.s_addr;
906 if ((ipaddr & mask) == (ina & mask))
907 break; /* ok, we got it! */
908 }
909
910 if (ifr >= ifend)
911 goto done;
912
913 /*
914 * Now scan through again looking for a link-level address
915 * for this interface.
916 */
917 ifp = ifr;
918 for (ifr = ifc.ifc_req; ifr < ifend; ifr = NEXTIFR(ifr))
919 if (strcmp(ifp->ifr_name, ifr->ifr_name) == 0 &&
920 ifr->ifr_addr.sa_family == AF_LINK)
921 break;
922 if (ifr >= ifend)
923 goto done;
924 /*
925 * Found the link-level address - copy it out
926 */
927 dla = (struct sockaddr_dl *) &ifr->ifr_addr;
928 memcpy(hwaddr, LLADDR(dla), dla->sdl_alen);
929 printf("using interface %s for proxy with address %s\n", ifp->ifr_name,
930 ether_ntoa(hwaddr));
931 retval = dla->sdl_alen;
932 done:
933 close(sock);
934 return (retval);
935 }
936