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[tomato.git] / release / src / router / busybox / networking / route.c

/* 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.
 */

//usage:#define route_trivial_usage
//usage:       "[{add|del|delete}]"
//usage:#define route_full_usage "\n\n"
//usage:       "Edit kernel routing tables\n"
//usage:     "\n        -n      Don't resolve names"
//usage:     "\n        -e      Display other/more information"
//usage:     "\n        -A inet" IF_FEATURE_IPV6("{6}") "       Select address family"

#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, SIOCGIFINDEX, &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);
                }
        }
        fclose(fp);
}

#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;
                while (1) {
                        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;
                        }
                }
        }
        fclose(fp);
}

#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;
}