1 /* vi: set sw=4 ts=4: */
5 * Similar to the standard Unix route, but with only the necessary
6 * parts for AF_INET and AF_INET6
8 * Bjorn Wesen, Axis Communications AB
10 * Author of the original route:
11 * Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>
12 * (derived from FvK's 'route.c 1.70 01/04/94')
14 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
17 * displayroute() code added by Vladimir N. Oleynik <dzo@simtreas.ru>
18 * adjustments by Larry Doolittle <LRDoolittle@lbl.gov>
20 * IPV6 support added by Bart Visscher <magick@linux-fan.com>
22 /* 2004/03/09 Manuel Novoa III <mjn3@codepoet.org>
24 * Rewritten to fix several bugs, add additional error checking, and
25 * remove ridiculous amounts of bloat.
28 //config: bool "route (8.9 kb)"
30 //config: select PLATFORM_LINUX
32 //config: Route displays or manipulates the kernel's IP routing tables.
34 //applet:IF_ROUTE(APPLET(route, BB_DIR_SBIN, BB_SUID_DROP))
36 //kbuild:lib-$(CONFIG_ROUTE) += route.o
38 //usage:#define route_trivial_usage
39 //usage: "[{add|del|delete}]"
40 //usage:#define route_full_usage "\n\n"
41 //usage: "Edit kernel routing tables\n"
42 //usage: "\n -n Don't resolve names"
43 //usage: "\n -e Display other/more information"
44 //usage: "\n -A inet" IF_FEATURE_IPV6("{6}") " Select address family"
46 #include <net/route.h>
50 #include "inet_common.h"
54 /* Keep this in sync with /usr/src/linux/include/linux/route.h */
55 #define RTF_UP 0x0001 /* route usable */
56 #define RTF_GATEWAY 0x0002 /* destination is a gateway */
57 #define RTF_HOST 0x0004 /* host entry (net otherwise) */
58 #define RTF_REINSTATE 0x0008 /* reinstate route after tmout */
59 #define RTF_DYNAMIC 0x0010 /* created dyn. (by redirect) */
60 #define RTF_MODIFIED 0x0020 /* modified dyn. (by redirect) */
61 #define RTF_MTU 0x0040 /* specific MTU for this route */
63 #define RTF_MSS RTF_MTU /* Compatibility :-( */
65 #define RTF_WINDOW 0x0080 /* per route window clamping */
66 #define RTF_IRTT 0x0100 /* Initial round trip time */
67 #define RTF_REJECT 0x0200 /* Reject route */
68 #define RTF_NONEXTHOP 0x00200000 /* route with no nexthop */
71 #if defined(SIOCADDRTOLD) || defined(RTF_IRTT) /* route */
72 #define HAVE_NEW_ADDRT 1
76 #define mask_in_addr(x) (((struct sockaddr_in *)&((x).rt_genmask))->sin_addr.s_addr)
77 #define full_mask(x) (x)
79 #define mask_in_addr(x) ((x).rt_genmask)
80 #define full_mask(x) (((struct sockaddr_in *)&(x))->sin_addr.s_addr)
83 /* The RTACTION entries must agree with tbl_verb[] below! */
84 #define RTACTION_ADD 1
85 #define RTACTION_DEL 2
87 /* For the various tbl_*[] arrays, the 1st byte is the offset to
88 * the next entry and the 2nd byte is return value. */
93 /* We remap '-' to '#' to avoid problems with getopt. */
94 static const char tbl_hash_net_host[] ALIGN1 =
96 /* "\010\002#host\0" */
97 "\007\002#host" /* Since last, we can save a byte. */
100 #define KW_TAKES_ARG 020
101 #define KW_SETS_FLAG 040
103 #define KW_IPVx_METRIC 020
104 #define KW_IPVx_NETMASK 021
105 #define KW_IPVx_GATEWAY 022
106 #define KW_IPVx_MSS 023
107 #define KW_IPVx_WINDOW 024
108 #define KW_IPVx_IRTT 025
109 #define KW_IPVx_DEVICE 026
111 #define KW_IPVx_FLAG_ONLY 040
112 #define KW_IPVx_REJECT 040
113 #define KW_IPVx_MOD 041
114 #define KW_IPVx_DYN 042
115 #define KW_IPVx_REINSTATE 043
117 static const char tbl_ipvx[] ALIGN1 =
118 /* 020 is the "takes an arg" bit */
132 /* 040 is the "sets a flag" bit - MUST match flags_ipvx[] values below. */
138 /* "\014\043reinstate\0" */
139 "\013\043reinstate" /* Since last, we can save a byte. */
142 static const uint16_t flags_ipvx[] = { /* MUST match tbl_ipvx[] values above. */
151 static int kw_lookup(const char *kwtbl, char ***pargs)
155 if (strcmp(kwtbl+2, **pargs) == 0) { /* Found a match. */
157 if (kwtbl[1] & KW_TAKES_ARG) {
158 if (!**pargs) { /* No more args! */
161 *pargs += 1; /* Calling routine will use args[-1]. */
171 /* Add or delete a route, depending on action. */
173 static NOINLINE void INET_setroute(int action, char **args)
175 /* char buffer instead of bona-fide struct avoids aliasing warning */
176 char rt_buf[sizeof(struct rtentry)];
177 struct rtentry *const rt = (void *)rt_buf;
179 const char *netmask = NULL;
180 int skfd, isnet, xflag;
182 /* Grab the -net or -host options. Remember they were transformed. */
183 xflag = kw_lookup(tbl_hash_net_host, &args);
185 /* If we did grab -net or -host, make sure we still have an arg left. */
190 /* Clean out the RTREQ structure. */
191 memset(rt, 0, sizeof(*rt));
194 const char *target = *args++;
197 /* recognize x.x.x.x/mask format. */
198 prefix = strchr(target, '/');
202 prefix_len = xatoul_range(prefix+1, 0, 32);
203 mask_in_addr(*rt) = htonl( ~(0xffffffffUL >> prefix_len));
206 rt->rt_genmask.sa_family = AF_INET;
209 /* Default netmask. */
212 /* Prefer hostname lookup is -host flag (xflag==1) was given. */
213 isnet = INET_resolve(target, (struct sockaddr_in *) &rt->rt_dst,
214 (xflag & HOST_FLAG));
216 bb_error_msg_and_die("resolving %s", target);
219 /* do not destroy prefix for process args */
224 if (xflag) { /* Reinit isnet if -net or -host was specified. */
225 isnet = (xflag & NET_FLAG);
228 /* Fill in the other fields. */
229 rt->rt_flags = ((isnet) ? RTF_UP : (RTF_UP | RTF_HOST));
232 int k = kw_lookup(tbl_ipvx, &args);
233 const char *args_m1 = args[-1];
235 if (k & KW_IPVx_FLAG_ONLY) {
236 rt->rt_flags |= flags_ipvx[k & 3];
241 if (k == KW_IPVx_METRIC) {
242 rt->rt_metric = xatoul(args_m1) + 1;
247 if (k == KW_IPVx_NETMASK) {
248 struct sockaddr mask;
250 if (mask_in_addr(*rt)) {
255 isnet = INET_resolve(netmask, (struct sockaddr_in *) &mask, 0);
257 bb_error_msg_and_die("resolving %s", netmask);
259 rt->rt_genmask = full_mask(mask);
263 if (k == KW_IPVx_GATEWAY) {
264 if (rt->rt_flags & RTF_GATEWAY) {
268 isnet = INET_resolve(args_m1,
269 (struct sockaddr_in *) &rt->rt_gateway, 1);
270 rt->rt_flags |= RTF_GATEWAY;
274 bb_error_msg_and_die("resolving %s", args_m1);
276 bb_error_msg_and_die("gateway %s is a NETWORK", args_m1);
281 if (k == KW_IPVx_MSS) { /* Check valid MSS bounds. */
282 rt->rt_flags |= RTF_MSS;
283 rt->rt_mss = xatoul_range(args_m1, 64, 32768);
287 if (k == KW_IPVx_WINDOW) { /* Check valid window bounds. */
288 rt->rt_flags |= RTF_WINDOW;
289 rt->rt_window = xatoul_range(args_m1, 128, INT_MAX);
294 if (k == KW_IPVx_IRTT) {
295 rt->rt_flags |= RTF_IRTT;
296 rt->rt_irtt = xatoul(args_m1);
297 rt->rt_irtt *= (bb_clk_tck() / 100); /* FIXME */
298 #if 0 /* FIXME: do we need to check anything of this? */
299 if (rt->rt_irtt < 1 || rt->rt_irtt > (120 * HZ)) {
300 bb_error_msg_and_die("bad irtt");
307 /* Device is special in that it can be the last arg specified
308 * and doesn't require the dev/device keyword in that case. */
309 if (!rt->rt_dev && ((k == KW_IPVx_DEVICE) || (!k && !*++args))) {
310 /* Don't use args_m1 here since args may have changed! */
311 rt->rt_dev = args[-1];
315 /* Nothing matched. */
320 if ((rt->rt_flags & RTF_REJECT) && !rt->rt_dev) {
321 rt->rt_dev = (char*)"lo";
325 /* sanity checks.. */
326 if (mask_in_addr(*rt)) {
327 uint32_t mask = mask_in_addr(*rt);
330 if ((rt->rt_flags & RTF_HOST) && mask != 0xffffffff) {
331 bb_error_msg_and_die("netmask %.8x and host route conflict",
332 (unsigned int) mask);
334 if (mask & (mask + 1)) {
335 bb_error_msg_and_die("bogus netmask %s", netmask);
337 mask = ((struct sockaddr_in *) &rt->rt_dst)->sin_addr.s_addr;
338 if (mask & ~(uint32_t)mask_in_addr(*rt)) {
339 bb_error_msg_and_die("netmask and route address conflict");
343 /* Fill out netmask if still unset */
344 if ((action == RTACTION_ADD) && (rt->rt_flags & RTF_HOST)) {
345 mask_in_addr(*rt) = 0xffffffff;
348 /* Create a socket to the INET kernel. */
349 skfd = xsocket(AF_INET, SOCK_DGRAM, 0);
351 if (action == RTACTION_ADD)
352 xioctl(skfd, SIOCADDRT, rt);
354 xioctl(skfd, SIOCDELRT, rt);
356 if (ENABLE_FEATURE_CLEAN_UP) close(skfd);
359 #if ENABLE_FEATURE_IPV6
361 static NOINLINE void INET6_setroute(int action, char **args)
363 struct sockaddr_in6 sa6;
365 int prefix_len, skfd;
368 /* We know args isn't NULL from the check in route_main. */
369 const char *target = *args++;
371 if (strcmp(target, "default") == 0) {
373 memset(&sa6, 0, sizeof(sa6));
376 cp = strchr(target, '/'); /* Yes... const to non is ok. */
379 prefix_len = xatoul_range(cp + 1, 0, 128);
383 if (INET6_resolve(target, (struct sockaddr_in6 *) &sa6) < 0) {
384 bb_error_msg_and_die("resolving %s", target);
388 /* Clean out the RTREQ structure. */
389 memset(&rt, 0, sizeof(rt));
391 memcpy(&rt.rtmsg_dst, sa6.sin6_addr.s6_addr, sizeof(struct in6_addr));
393 /* Fill in the other fields. */
394 rt.rtmsg_dst_len = prefix_len;
395 rt.rtmsg_flags = ((prefix_len == 128) ? (RTF_UP|RTF_HOST) : RTF_UP);
401 int k = kw_lookup(tbl_ipvx, &args);
402 const char *args_m1 = args[-1];
404 if ((k == KW_IPVx_MOD) || (k == KW_IPVx_DYN)) {
405 rt.rtmsg_flags |= flags_ipvx[k & 3];
409 if (k == KW_IPVx_METRIC) {
410 rt.rtmsg_metric = xatoul(args_m1);
414 if (k == KW_IPVx_GATEWAY) {
415 if (rt.rtmsg_flags & RTF_GATEWAY) {
419 if (INET6_resolve(args_m1, (struct sockaddr_in6 *) &sa6) < 0) {
420 bb_error_msg_and_die("resolving %s", args_m1);
422 memcpy(&rt.rtmsg_gateway, sa6.sin6_addr.s6_addr,
423 sizeof(struct in6_addr));
424 rt.rtmsg_flags |= RTF_GATEWAY;
428 /* Device is special in that it can be the last arg specified
429 * and doesn't require the dev/device keyword in that case. */
430 if (!devname && ((k == KW_IPVx_DEVICE) || (!k && !*++args))) {
431 /* Don't use args_m1 here since args may have changed! */
436 /* Nothing matched. */
440 /* Create a socket to the INET6 kernel. */
441 skfd = xsocket(AF_INET6, SOCK_DGRAM, 0);
443 rt.rtmsg_ifindex = 0;
447 memset(&ifr, 0, sizeof(ifr));
448 strncpy_IFNAMSIZ(ifr.ifr_name, devname);
449 xioctl(skfd, SIOCGIFINDEX, &ifr);
450 rt.rtmsg_ifindex = ifr.ifr_ifindex;
453 /* Tell the kernel to accept this route. */
454 if (action == RTACTION_ADD)
455 xioctl(skfd, SIOCADDRT, &rt);
457 xioctl(skfd, SIOCDELRT, &rt);
459 if (ENABLE_FEATURE_CLEAN_UP) close(skfd);
464 IF_NOT_FEATURE_IPV6(uint16_t)
465 IF_FEATURE_IPV6(unsigned)
466 flagvals[] = { /* Must agree with flagchars[]. */
473 #if ENABLE_FEATURE_IPV6
478 RTF_NONEXTHOP, /* this one doesn't fit into 16 bits */
481 /* Must agree with flagvals[]. */
482 static const char flagchars[] ALIGN1 =
484 #if ENABLE_FEATURE_IPV6
488 #define IPV4_MASK (RTF_UP|RTF_GATEWAY|RTF_HOST|RTF_REINSTATE|RTF_DYNAMIC|RTF_MODIFIED)
489 #define IPV6_MASK (RTF_UP|RTF_GATEWAY|RTF_HOST|RTF_DEFAULT|RTF_ADDRCONF|RTF_CACHE|RTF_REJECT|RTF_NONEXTHOP)
491 static void set_flags(char *flagstr, int flags)
495 for (i = 0; (*flagstr = flagchars[i]) != 0; i++) {
496 if (flags & flagvals[i]) {
502 /* also used in netstat */
503 void FAST_FUNC bb_displayroutes(int noresolve, int netstatfmt)
505 char devname[64], flags[16], *sdest, *sgw;
506 unsigned long d, g, m;
508 int flgs, ref, use, metric, mtu, win, ir;
509 struct sockaddr_in s_addr;
512 FILE *fp = xfopen_for_read("/proc/net/route");
514 printf("Kernel IP routing table\n"
515 "Destination Gateway Genmask Flags %s Iface\n",
516 netstatfmt ? " MSS Window irtt" : "Metric Ref Use");
518 /* Skip the first line. */
519 r = fscanf(fp, "%*[^\n]\n");
521 /* Empty line, read error, or EOF. Yes, if routing table
522 * is completely empty, /proc/net/route has no header.
527 r = fscanf(fp, "%63s%lx%lx%X%d%d%d%lx%d%d%d\n",
528 devname, &d, &g, &flgs, &ref, &use, &metric, &m,
532 if ((r < 0) && feof(fp)) { /* EOF with no (nonspace) chars read. */
535 bb_perror_msg_and_die(bb_msg_read_error);
538 if (!(flgs & RTF_UP)) { /* Skip interfaces that are down. */
542 set_flags(flags, (flgs & IPV4_MASK));
544 if (flgs & RTF_REJECT) {
549 memset(&s_addr, 0, sizeof(struct sockaddr_in));
550 s_addr.sin_family = AF_INET;
551 s_addr.sin_addr.s_addr = d;
552 sdest = INET_rresolve(&s_addr, (noresolve | 0x8000), m); /* 'default' instead of '*' */
553 s_addr.sin_addr.s_addr = g;
554 sgw = INET_rresolve(&s_addr, (noresolve | 0x4000), m); /* Host instead of net */
556 /* "%15.15s" truncates hostnames, do we really want that? */
557 printf("%-15.15s %-15.15s %-16s%-6s", sdest, sgw, inet_ntoa(mask), flags);
561 printf("%5d %-5d %6d %s\n", mtu, win, ir, devname);
563 printf("%-6d %-2d %7d %s\n", metric, ref, use, devname);
569 #if ENABLE_FEATURE_IPV6
571 static void INET6_displayroutes(void)
573 char addr6[128], *naddr6;
574 /* In addr6x, we store both 40-byte ':'-delimited ipv6 addresses.
575 * We read the non-delimited strings into the tail of the buffer
576 * using fscanf and then modify the buffer by shifting forward
577 * while inserting ':'s and the nul terminator for the first string.
578 * Hence the strings are at addr6x and addr6x+40. This generates
579 * _much_ less code than the previous (upstream) approach. */
581 char iface[16], flags[16];
582 int iflags, metric, refcnt, use, prefix_len, slen;
583 struct sockaddr_in6 snaddr6;
585 FILE *fp = xfopen_for_read("/proc/net/ipv6_route");
587 printf("Kernel IPv6 routing table\n%-44s%-40s"
588 "Flags Metric Ref Use Iface\n",
589 "Destination", "Next Hop");
593 r = fscanf(fp, "%32s%x%*s%x%32s%x%x%x%x%s\n",
594 addr6x+14, &prefix_len, &slen, addr6x+40+7,
595 &metric, &refcnt, &use, &iflags, iface);
597 if ((r < 0) && feof(fp)) { /* EOF with no (nonspace) chars read. */
601 bb_perror_msg_and_die(bb_msg_read_error);
604 /* Do the addr6x shift-and-insert changes to ':'-delimit addresses.
605 * For now, always do this to validate the proc route format, even
606 * if the interface is down. */
613 if (i == 40) { /* nul terminator for 1st address? */
614 addr6x[39] = 0; /* Fixup... need 0 instead of ':'. */
615 ++p; /* Skip and continue. */
624 } while (i < 40+28+7);
627 set_flags(flags, (iflags & IPV6_MASK));
631 inet_pton(AF_INET6, addr6x + r,
632 (struct sockaddr *) &snaddr6.sin6_addr);
633 snaddr6.sin6_family = AF_INET6;
634 naddr6 = INET6_rresolve((struct sockaddr_in6 *) &snaddr6,
635 0x0fff /* Apparently, upstream never resolves. */
638 if (!r) { /* 1st pass */
639 snprintf(addr6, sizeof(addr6), "%s/%d", naddr6, prefix_len);
642 } else { /* 2nd pass */
643 /* Print the info. */
644 printf("%-43s %-39s %-5s %-6d %-2d %7d %-8s\n",
645 addr6, naddr6, flags, metric, refcnt, use, iface);
656 #define ROUTE_OPT_A 0x01
657 #define ROUTE_OPT_n 0x02
658 #define ROUTE_OPT_e 0x04
659 #define ROUTE_OPT_INET6 0x08 /* Not an actual option. See below. */
661 /* 1st byte is offset to next entry offset. 2nd byte is return value. */
662 /* 2nd byte matches RTACTION_* code */
663 static const char tbl_verb[] ALIGN1 =
666 /* "\011\002delete\0" */
667 "\010\002delete" /* Since it's last, we can save a byte. */
670 int route_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
671 int route_main(int argc UNUSED_PARAM, char **argv)
678 /* First, remap '-net' and '-host' to avoid getopt problems. */
681 if (strcmp(*p, "-net") == 0 || strcmp(*p, "-host") == 0) {
686 opt = getopt32(argv, "A:ne", &family);
688 if ((opt & ROUTE_OPT_A) && strcmp(family, "inet") != 0) {
689 #if ENABLE_FEATURE_IPV6
690 if (strcmp(family, "inet6") == 0) {
691 opt |= ROUTE_OPT_INET6; /* Set flag for ipv6. */
699 /* No more args means display the routing table. */
701 int noresolve = (opt & ROUTE_OPT_n) ? 0x0fff : 0;
702 #if ENABLE_FEATURE_IPV6
703 if (opt & ROUTE_OPT_INET6)
704 INET6_displayroutes();
707 bb_displayroutes(noresolve, opt & ROUTE_OPT_e);
709 fflush_stdout_and_exit(EXIT_SUCCESS);
712 /* Check verb. At the moment, must be add, del, or delete. */
713 what = kw_lookup(tbl_verb, &argv);
714 if (!what || !*argv) { /* Unknown verb or no more args. */
718 #if ENABLE_FEATURE_IPV6
719 if (opt & ROUTE_OPT_INET6)
720 INET6_setroute(what, argv);
723 INET_setroute(what, argv);