/* vi: set sw=4 ts=4: */ /* route * * Similar to the standard Unix route, but with only the necessary * parts for AF_INET and AF_INET6 * * Bjorn Wesen, Axis Communications AB * * Author of the original route: * Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org> * (derived from FvK's 'route.c 1.70 01/04/94') * * Licensed under GPLv2 or later, see file LICENSE in this source tree. * * * displayroute() code added by Vladimir N. Oleynik <dzo@simtreas.ru> * adjustments by Larry Doolittle <LRDoolittle@lbl.gov> * * IPV6 support added by Bart Visscher <magick@linux-fan.com> */ /* 2004/03/09 Manuel Novoa III <mjn3@codepoet.org> * * Rewritten to fix several bugs, add additional error checking, and * remove ridiculous amounts of bloat. */ #include <net/route.h> #include <net/if.h> #include "libbb.h" #include "inet_common.h" #ifndef RTF_UP /* Keep this in sync with /usr/src/linux/include/linux/route.h */ #define RTF_UP 0x0001 /* route usable */ #define RTF_GATEWAY 0x0002 /* destination is a gateway */ #define RTF_HOST 0x0004 /* host entry (net otherwise) */ #define RTF_REINSTATE 0x0008 /* reinstate route after tmout */ #define RTF_DYNAMIC 0x0010 /* created dyn. (by redirect) */ #define RTF_MODIFIED 0x0020 /* modified dyn. (by redirect) */ #define RTF_MTU 0x0040 /* specific MTU for this route */ #ifndef RTF_MSS #define RTF_MSS RTF_MTU /* Compatibility :-( */ #endif #define RTF_WINDOW 0x0080 /* per route window clamping */ #define RTF_IRTT 0x0100 /* Initial round trip time */ #define RTF_REJECT 0x0200 /* Reject route */ #endif #if defined(SIOCADDRTOLD) || defined(RTF_IRTT) /* route */ #define HAVE_NEW_ADDRT 1 #endif #if HAVE_NEW_ADDRT #define mask_in_addr(x) (((struct sockaddr_in *)&((x).rt_genmask))->sin_addr.s_addr) #define full_mask(x) (x) #else #define mask_in_addr(x) ((x).rt_genmask) #define full_mask(x) (((struct sockaddr_in *)&(x))->sin_addr.s_addr) #endif /* The RTACTION entries must agree with tbl_verb[] below! */ #define RTACTION_ADD 1 #define RTACTION_DEL 2 /* For the various tbl_*[] arrays, the 1st byte is the offset to * the next entry and the 2nd byte is return value. */ #define NET_FLAG 1 #define HOST_FLAG 2 /* We remap '-' to '#' to avoid problems with getopt. */ static const char tbl_hash_net_host[] ALIGN1 = "\007\001#net\0" /* "\010\002#host\0" */ "\007\002#host" /* Since last, we can save a byte. */ ; #define KW_TAKES_ARG 020 #define KW_SETS_FLAG 040 #define KW_IPVx_METRIC 020 #define KW_IPVx_NETMASK 021 #define KW_IPVx_GATEWAY 022 #define KW_IPVx_MSS 023 #define KW_IPVx_WINDOW 024 #define KW_IPVx_IRTT 025 #define KW_IPVx_DEVICE 026 #define KW_IPVx_FLAG_ONLY 040 #define KW_IPVx_REJECT 040 #define KW_IPVx_MOD 041 #define KW_IPVx_DYN 042 #define KW_IPVx_REINSTATE 043 static const char tbl_ipvx[] ALIGN1 = /* 020 is the "takes an arg" bit */ #if HAVE_NEW_ADDRT "\011\020metric\0" #endif "\012\021netmask\0" "\005\022gw\0" "\012\022gateway\0" "\006\023mss\0" "\011\024window\0" #ifdef RTF_IRTT "\007\025irtt\0" #endif "\006\026dev\0" "\011\026device\0" /* 040 is the "sets a flag" bit - MUST match flags_ipvx[] values below. */ #ifdef RTF_REJECT "\011\040reject\0" #endif "\006\041mod\0" "\006\042dyn\0" /* "\014\043reinstate\0" */ "\013\043reinstate" /* Since last, we can save a byte. */ ; static const int flags_ipvx[] = { /* MUST match tbl_ipvx[] values above. */ #ifdef RTF_REJECT RTF_REJECT, #endif RTF_MODIFIED, RTF_DYNAMIC, RTF_REINSTATE }; static int kw_lookup(const char *kwtbl, char ***pargs) { if (**pargs) { do { if (strcmp(kwtbl+2, **pargs) == 0) { /* Found a match. */ *pargs += 1; if (kwtbl[1] & KW_TAKES_ARG) { if (!**pargs) { /* No more args! */ bb_show_usage(); } *pargs += 1; /* Calling routine will use args[-1]. */ } return kwtbl[1]; } kwtbl += *kwtbl; } while (*kwtbl); } return 0; } /* Add or delete a route, depending on action. */ static NOINLINE void INET_setroute(int action, char **args) { /* char buffer instead of bona-fide struct avoids aliasing warning */ char rt_buf[sizeof(struct rtentry)]; struct rtentry *const rt = (void *)rt_buf; const char *netmask = NULL; int skfd, isnet, xflag; /* Grab the -net or -host options. Remember they were transformed. */ xflag = kw_lookup(tbl_hash_net_host, &args); /* If we did grab -net or -host, make sure we still have an arg left. */ if (*args == NULL) { bb_show_usage(); } /* Clean out the RTREQ structure. */ memset(rt, 0, sizeof(*rt)); { const char *target = *args++; char *prefix; /* recognize x.x.x.x/mask format. */ prefix = strchr(target, '/'); if (prefix) { int prefix_len; prefix_len = xatoul_range(prefix+1, 0, 32); mask_in_addr(*rt) = htonl( ~(0xffffffffUL >> prefix_len)); *prefix = '\0'; #if HAVE_NEW_ADDRT rt->rt_genmask.sa_family = AF_INET; #endif } else { /* Default netmask. */ netmask = "default"; } /* Prefer hostname lookup is -host flag (xflag==1) was given. */ isnet = INET_resolve(target, (struct sockaddr_in *) &rt->rt_dst, (xflag & HOST_FLAG)); if (isnet < 0) { bb_error_msg_and_die("resolving %s", target); } if (prefix) { /* do not destroy prefix for process args */ *prefix = '/'; } } if (xflag) { /* Reinit isnet if -net or -host was specified. */ isnet = (xflag & NET_FLAG); } /* Fill in the other fields. */ rt->rt_flags = ((isnet) ? RTF_UP : (RTF_UP | RTF_HOST)); while (*args) { int k = kw_lookup(tbl_ipvx, &args); const char *args_m1 = args[-1]; if (k & KW_IPVx_FLAG_ONLY) { rt->rt_flags |= flags_ipvx[k & 3]; continue; } #if HAVE_NEW_ADDRT if (k == KW_IPVx_METRIC) { rt->rt_metric = xatoul(args_m1) + 1; continue; } #endif if (k == KW_IPVx_NETMASK) { struct sockaddr mask; if (mask_in_addr(*rt)) { bb_show_usage(); } netmask = args_m1; isnet = INET_resolve(netmask, (struct sockaddr_in *) &mask, 0); if (isnet < 0) { bb_error_msg_and_die("resolving %s", netmask); } rt->rt_genmask = full_mask(mask); continue; } if (k == KW_IPVx_GATEWAY) { if (rt->rt_flags & RTF_GATEWAY) { bb_show_usage(); } isnet = INET_resolve(args_m1, (struct sockaddr_in *) &rt->rt_gateway, 1); rt->rt_flags |= RTF_GATEWAY; if (isnet) { if (isnet < 0) { bb_error_msg_and_die("resolving %s", args_m1); } bb_error_msg_and_die("gateway %s is a NETWORK", args_m1); } continue; } if (k == KW_IPVx_MSS) { /* Check valid MSS bounds. */ rt->rt_flags |= RTF_MSS; rt->rt_mss = xatoul_range(args_m1, 64, 32768); continue; } if (k == KW_IPVx_WINDOW) { /* Check valid window bounds. */ rt->rt_flags |= RTF_WINDOW; rt->rt_window = xatoul_range(args_m1, 128, INT_MAX); continue; } #ifdef RTF_IRTT if (k == KW_IPVx_IRTT) { rt->rt_flags |= RTF_IRTT; rt->rt_irtt = xatoul(args_m1); rt->rt_irtt *= (sysconf(_SC_CLK_TCK) / 100); /* FIXME */ #if 0 /* FIXME: do we need to check anything of this? */ if (rt->rt_irtt < 1 || rt->rt_irtt > (120 * HZ)) { bb_error_msg_and_die("bad irtt"); } #endif continue; } #endif /* Device is special in that it can be the last arg specified * and doesn't requre the dev/device keyword in that case. */ if (!rt->rt_dev && ((k == KW_IPVx_DEVICE) || (!k && !*++args))) { /* Don't use args_m1 here since args may have changed! */ rt->rt_dev = args[-1]; continue; } /* Nothing matched. */ bb_show_usage(); } #ifdef RTF_REJECT if ((rt->rt_flags & RTF_REJECT) && !rt->rt_dev) { rt->rt_dev = (char*)"lo"; } #endif /* sanity checks.. */ if (mask_in_addr(*rt)) { uint32_t mask = mask_in_addr(*rt); mask = ~ntohl(mask); if ((rt->rt_flags & RTF_HOST) && mask != 0xffffffff) { bb_error_msg_and_die("netmask %.8x and host route conflict", (unsigned int) mask); } if (mask & (mask + 1)) { bb_error_msg_and_die("bogus netmask %s", netmask); } mask = ((struct sockaddr_in *) &rt->rt_dst)->sin_addr.s_addr; if (mask & ~(uint32_t)mask_in_addr(*rt)) { bb_error_msg_and_die("netmask and route address conflict"); } } /* Fill out netmask if still unset */ if ((action == RTACTION_ADD) && (rt->rt_flags & RTF_HOST)) { mask_in_addr(*rt) = 0xffffffff; } /* Create a socket to the INET kernel. */ skfd = xsocket(AF_INET, SOCK_DGRAM, 0); if (action == RTACTION_ADD) xioctl(skfd, SIOCADDRT, rt); else xioctl(skfd, SIOCDELRT, rt); if (ENABLE_FEATURE_CLEAN_UP) close(skfd); } #if ENABLE_FEATURE_IPV6 static NOINLINE void INET6_setroute(int action, char **args) { struct sockaddr_in6 sa6; struct in6_rtmsg rt; int prefix_len, skfd; const char *devname; /* We know args isn't NULL from the check in route_main. */ const char *target = *args++; if (strcmp(target, "default") == 0) { prefix_len = 0; memset(&sa6, 0, sizeof(sa6)); } else { char *cp; cp = strchr(target, '/'); /* Yes... const to non is ok. */ if (cp) { *cp = '\0'; prefix_len = xatoul_range(cp + 1, 0, 128); } else { prefix_len = 128; } if (INET6_resolve(target, (struct sockaddr_in6 *) &sa6) < 0) { bb_error_msg_and_die("resolving %s", target); } } /* Clean out the RTREQ structure. */ memset(&rt, 0, sizeof(rt)); memcpy(&rt.rtmsg_dst, sa6.sin6_addr.s6_addr, sizeof(struct in6_addr)); /* Fill in the other fields. */ rt.rtmsg_dst_len = prefix_len; rt.rtmsg_flags = ((prefix_len == 128) ? (RTF_UP|RTF_HOST) : RTF_UP); rt.rtmsg_metric = 1; devname = NULL; while (*args) { int k = kw_lookup(tbl_ipvx, &args); const char *args_m1 = args[-1]; if ((k == KW_IPVx_MOD) || (k == KW_IPVx_DYN)) { rt.rtmsg_flags |= flags_ipvx[k & 3]; continue; } if (k == KW_IPVx_METRIC) { rt.rtmsg_metric = xatoul(args_m1); continue; } if (k == KW_IPVx_GATEWAY) { if (rt.rtmsg_flags & RTF_GATEWAY) { bb_show_usage(); } if (INET6_resolve(args_m1, (struct sockaddr_in6 *) &sa6) < 0) { bb_error_msg_and_die("resolving %s", args_m1); } memcpy(&rt.rtmsg_gateway, sa6.sin6_addr.s6_addr, sizeof(struct in6_addr)); rt.rtmsg_flags |= RTF_GATEWAY; continue; } /* Device is special in that it can be the last arg specified * and doesn't requre the dev/device keyword in that case. */ if (!devname && ((k == KW_IPVx_DEVICE) || (!k && !*++args))) { /* Don't use args_m1 here since args may have changed! */ devname = args[-1]; continue; } /* Nothing matched. */ bb_show_usage(); } /* Create a socket to the INET6 kernel. */ skfd = xsocket(AF_INET6, SOCK_DGRAM, 0); rt.rtmsg_ifindex = 0; if (devname) { struct ifreq ifr; memset(&ifr, 0, sizeof(ifr)); strncpy_IFNAMSIZ(ifr.ifr_name, devname); xioctl(skfd, SIOGIFINDEX, &ifr); rt.rtmsg_ifindex = ifr.ifr_ifindex; } /* Tell the kernel to accept this route. */ if (action == RTACTION_ADD) xioctl(skfd, SIOCADDRT, &rt); else xioctl(skfd, SIOCDELRT, &rt); if (ENABLE_FEATURE_CLEAN_UP) close(skfd); } #endif static const unsigned flagvals[] = { /* Must agree with flagchars[]. */ RTF_GATEWAY, RTF_HOST, RTF_REINSTATE, RTF_DYNAMIC, RTF_MODIFIED, #if ENABLE_FEATURE_IPV6 RTF_DEFAULT, RTF_ADDRCONF, RTF_CACHE #endif }; #define IPV4_MASK (RTF_GATEWAY|RTF_HOST|RTF_REINSTATE|RTF_DYNAMIC|RTF_MODIFIED) #define IPV6_MASK (RTF_GATEWAY|RTF_HOST|RTF_DEFAULT|RTF_ADDRCONF|RTF_CACHE) /* Must agree with flagvals[]. */ static const char flagchars[] ALIGN1 = "GHRDM" #if ENABLE_FEATURE_IPV6 "DAC" #endif ; static void set_flags(char *flagstr, int flags) { int i; *flagstr++ = 'U'; for (i = 0; (*flagstr = flagchars[i]) != 0; i++) { if (flags & flagvals[i]) { ++flagstr; } } } /* also used in netstat */ void FAST_FUNC bb_displayroutes(int noresolve, int netstatfmt) { char devname[64], flags[16], *sdest, *sgw; unsigned long d, g, m; int flgs, ref, use, metric, mtu, win, ir; struct sockaddr_in s_addr; struct in_addr mask; FILE *fp = xfopen_for_read("/proc/net/route"); printf("Kernel IP routing table\n" "Destination Gateway Genmask Flags %s Iface\n", netstatfmt ? " MSS Window irtt" : "Metric Ref Use"); if (fscanf(fp, "%*[^\n]\n") < 0) { /* Skip the first line. */ goto ERROR; /* Empty or missing line, or read error. */ } while (1) { int r; r = fscanf(fp, "%63s%lx%lx%X%d%d%d%lx%d%d%d\n", devname, &d, &g, &flgs, &ref, &use, &metric, &m, &mtu, &win, &ir); if (r != 11) { if ((r < 0) && feof(fp)) { /* EOF with no (nonspace) chars read. */ break; } ERROR: bb_error_msg_and_die("fscanf"); } if (!(flgs & RTF_UP)) { /* Skip interfaces that are down. */ continue; } set_flags(flags, (flgs & IPV4_MASK)); #ifdef RTF_REJECT if (flgs & RTF_REJECT) { flags[0] = '!'; } #endif memset(&s_addr, 0, sizeof(struct sockaddr_in)); s_addr.sin_family = AF_INET; s_addr.sin_addr.s_addr = d; sdest = INET_rresolve(&s_addr, (noresolve | 0x8000), m); /* 'default' instead of '*' */ s_addr.sin_addr.s_addr = g; sgw = INET_rresolve(&s_addr, (noresolve | 0x4000), m); /* Host instead of net */ mask.s_addr = m; /* "%15.15s" truncates hostnames, do we really want that? */ printf("%-15.15s %-15.15s %-16s%-6s", sdest, sgw, inet_ntoa(mask), flags); free(sdest); free(sgw); if (netstatfmt) { printf("%5d %-5d %6d %s\n", mtu, win, ir, devname); } else { printf("%-6d %-2d %7d %s\n", metric, ref, use, devname); } } } #if ENABLE_FEATURE_IPV6 static void INET6_displayroutes(void) { char addr6[128], *naddr6; /* In addr6x, we store both 40-byte ':'-delimited ipv6 addresses. * We read the non-delimited strings into the tail of the buffer * using fscanf and then modify the buffer by shifting forward * while inserting ':'s and the nul terminator for the first string. * Hence the strings are at addr6x and addr6x+40. This generates * _much_ less code than the previous (upstream) approach. */ char addr6x[80]; char iface[16], flags[16]; int iflags, metric, refcnt, use, prefix_len, slen; struct sockaddr_in6 snaddr6; FILE *fp = xfopen_for_read("/proc/net/ipv6_route"); printf("Kernel IPv6 routing table\n%-44s%-40s" "Flags Metric Ref Use Iface\n", "Destination", "Next Hop"); while (1) { int r; r = fscanf(fp, "%32s%x%*s%x%32s%x%x%x%x%s\n", addr6x+14, &prefix_len, &slen, addr6x+40+7, &metric, &use, &refcnt, &iflags, iface); if (r != 9) { if ((r < 0) && feof(fp)) { /* EOF with no (nonspace) chars read. */ break; } ERROR: bb_error_msg_and_die("fscanf"); } /* Do the addr6x shift-and-insert changes to ':'-delimit addresses. * For now, always do this to validate the proc route format, even * if the interface is down. */ { int i = 0; char *p = addr6x+14; do { if (!*p) { if (i == 40) { /* nul terminator for 1st address? */ addr6x[39] = 0; /* Fixup... need 0 instead of ':'. */ ++p; /* Skip and continue. */ continue; } goto ERROR; } addr6x[i++] = *p++; if (!((i+1) % 5)) { addr6x[i++] = ':'; } } while (i < 40+28+7); } if (!(iflags & RTF_UP)) { /* Skip interfaces that are down. */ continue; } set_flags(flags, (iflags & IPV6_MASK)); r = 0; do { inet_pton(AF_INET6, addr6x + r, (struct sockaddr *) &snaddr6.sin6_addr); snaddr6.sin6_family = AF_INET6; naddr6 = INET6_rresolve((struct sockaddr_in6 *) &snaddr6, 0x0fff /* Apparently, upstream never resolves. */ ); if (!r) { /* 1st pass */ snprintf(addr6, sizeof(addr6), "%s/%d", naddr6, prefix_len); r += 40; free(naddr6); } else { /* 2nd pass */ /* Print the info. */ printf("%-43s %-39s %-5s %-6d %-2d %7d %-8s\n", addr6, naddr6, flags, metric, refcnt, use, iface); free(naddr6); break; } } while (1); } } #endif #define ROUTE_OPT_A 0x01 #define ROUTE_OPT_n 0x02 #define ROUTE_OPT_e 0x04 #define ROUTE_OPT_INET6 0x08 /* Not an actual option. See below. */ /* 1st byte is offset to next entry offset. 2nd byte is return value. */ /* 2nd byte matches RTACTION_* code */ static const char tbl_verb[] ALIGN1 = "\006\001add\0" "\006\002del\0" /* "\011\002delete\0" */ "\010\002delete" /* Since it's last, we can save a byte. */ ; int route_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int route_main(int argc UNUSED_PARAM, char **argv) { unsigned opt; int what; char *family; char **p; /* First, remap '-net' and '-host' to avoid getopt problems. */ p = argv; while (*++p) { if (strcmp(*p, "-net") == 0 || strcmp(*p, "-host") == 0) { p[0][0] = '#'; } } opt = getopt32(argv, "A:ne", &family); if ((opt & ROUTE_OPT_A) && strcmp(family, "inet") != 0) { #if ENABLE_FEATURE_IPV6 if (strcmp(family, "inet6") == 0) { opt |= ROUTE_OPT_INET6; /* Set flag for ipv6. */ } else #endif bb_show_usage(); } argv += optind; /* No more args means display the routing table. */ if (!*argv) { int noresolve = (opt & ROUTE_OPT_n) ? 0x0fff : 0; #if ENABLE_FEATURE_IPV6 if (opt & ROUTE_OPT_INET6) INET6_displayroutes(); else #endif bb_displayroutes(noresolve, opt & ROUTE_OPT_e); fflush_stdout_and_exit(EXIT_SUCCESS); } /* Check verb. At the moment, must be add, del, or delete. */ what = kw_lookup(tbl_verb, &argv); if (!what || !*argv) { /* Unknown verb or no more args. */ bb_show_usage(); } #if ENABLE_FEATURE_IPV6 if (opt & ROUTE_OPT_INET6) INET6_setroute(what, argv); else #endif INET_setroute(what, argv); return EXIT_SUCCESS; }