source: MondoRescue/branches/stable/mindi-busybox/networking/libiproute/iproute.c @ 1770

/* vi: set sw=4 ts=4: */
/*
 * iproute.c        "ip route".
 *
 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
 *
 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 *
 * Changes:
 *
 * Rani Assaf <rani@magic.metawire.com> 980929: resolve addresses
 * Kunihiro Ishiguro <kunihiro@zebra.org> 001102: rtnh_ifindex was not initialized
 */

#include "ip_common.h"  /* #include "libbb.h" is inside */
#include "rt_names.h"
#include "utils.h"

#ifndef RTAX_RTTVAR
#define RTAX_RTTVAR RTAX_HOPS
#endif


typedef struct filter_t {
    int tb;
    int flushed;
    char *flushb;
    int flushp;
    int flushe;
    struct rtnl_handle *rth;
    int protocol, protocolmask;
    int scope, scopemask;
    int type, typemask;
    int tos, tosmask;
    int iif, iifmask;
    int oif, oifmask;
    int realm, realmmask;
    inet_prefix rprefsrc;
    inet_prefix rvia;
    inet_prefix rdst;
    inet_prefix mdst;
    inet_prefix rsrc;
    inet_prefix msrc;
} filter_t;

#define filter (*(filter_t*)&bb_common_bufsiz1)

static int flush_update(void)
{
    if (rtnl_send(filter.rth, filter.flushb, filter.flushp) < 0) {
        bb_perror_msg("failed to send flush request");
        return -1;
    }
    filter.flushp = 0;
    return 0;
}

static unsigned get_hz(void)
{
    static unsigned hz_internal;
    FILE *fp;

    if (hz_internal)
        return hz_internal;

    fp = fopen("/proc/net/psched", "r");
    if (fp) {
        unsigned nom, denom;

        if (fscanf(fp, "%*08x%*08x%08x%08x", &nom, &denom) == 2)
            if (nom == 1000000)
                hz_internal = denom;
        fclose(fp);
    }
    if (!hz_internal)
        hz_internal = sysconf(_SC_CLK_TCK);
    return hz_internal;
}

static int print_route(struct sockaddr_nl *who ATTRIBUTE_UNUSED,
        struct nlmsghdr *n, void *arg)
{
    FILE *fp = (FILE*)arg;
    struct rtmsg *r = NLMSG_DATA(n);
    int len = n->nlmsg_len;
    struct rtattr * tb[RTA_MAX+1];
    char abuf[256];
    inet_prefix dst;
    inet_prefix src;
    int host_len = -1;
    SPRINT_BUF(b1);


    if (n->nlmsg_type != RTM_NEWROUTE && n->nlmsg_type != RTM_DELROUTE) {
        fprintf(stderr, "Not a route: %08x %08x %08x\n",
            n->nlmsg_len, n->nlmsg_type, n->nlmsg_flags);
        return 0;
    }
    if (filter.flushb && n->nlmsg_type != RTM_NEWROUTE)
        return 0;
    len -= NLMSG_LENGTH(sizeof(*r));
    if (len < 0)
        bb_error_msg_and_die("wrong nlmsg len %d", len);

    if (r->rtm_family == AF_INET6)
        host_len = 128;
    else if (r->rtm_family == AF_INET)
        host_len = 32;

    if (r->rtm_family == AF_INET6) {
        if (filter.tb) {
            if (filter.tb < 0) {
                if (!(r->rtm_flags&RTM_F_CLONED)) {
                    return 0;
                }
            } else {
                if (r->rtm_flags&RTM_F_CLONED) {
                    return 0;
                }
                if (filter.tb == RT_TABLE_LOCAL) {
                    if (r->rtm_type != RTN_LOCAL) {
                        return 0;
                    }
                } else if (filter.tb == RT_TABLE_MAIN) {
                    if (r->rtm_type == RTN_LOCAL) {
                        return 0;
                    }
                } else {
                    return 0;
                }
            }
        }
    } else {
        if (filter.tb > 0 && filter.tb != r->rtm_table) {
            return 0;
        }
    }
    if (filter.rdst.family &&
        (r->rtm_family != filter.rdst.family || filter.rdst.bitlen > r->rtm_dst_len)) {
        return 0;
    }
    if (filter.mdst.family &&
        (r->rtm_family != filter.mdst.family ||
         (filter.mdst.bitlen >= 0 && filter.mdst.bitlen < r->rtm_dst_len))) {
        return 0;
    }
    if (filter.rsrc.family &&
        (r->rtm_family != filter.rsrc.family || filter.rsrc.bitlen > r->rtm_src_len)) {
        return 0;
    }
    if (filter.msrc.family &&
        (r->rtm_family != filter.msrc.family ||
         (filter.msrc.bitlen >= 0 && filter.msrc.bitlen < r->rtm_src_len))) {
        return 0;
    }

    memset(tb, 0, sizeof(tb));
    parse_rtattr(tb, RTA_MAX, RTM_RTA(r), len);

    if (filter.rdst.family && inet_addr_match(&dst, &filter.rdst, filter.rdst.bitlen))
        return 0;
    if (filter.mdst.family && filter.mdst.bitlen >= 0 &&
        inet_addr_match(&dst, &filter.mdst, r->rtm_dst_len))
        return 0;

    if (filter.rsrc.family && inet_addr_match(&src, &filter.rsrc, filter.rsrc.bitlen))
        return 0;
    if (filter.msrc.family && filter.msrc.bitlen >= 0 &&
        inet_addr_match(&src, &filter.msrc, r->rtm_src_len))
        return 0;

    if (filter.flushb &&
        r->rtm_family == AF_INET6 &&
        r->rtm_dst_len == 0 &&
        r->rtm_type == RTN_UNREACHABLE &&
        tb[RTA_PRIORITY] &&
        *(int*)RTA_DATA(tb[RTA_PRIORITY]) == -1)
        return 0;

    if (filter.flushb) {
        struct nlmsghdr *fn;
        if (NLMSG_ALIGN(filter.flushp) + n->nlmsg_len > filter.flushe) {
            if (flush_update())
                bb_error_msg_and_die("flush");
        }
        fn = (struct nlmsghdr*)(filter.flushb + NLMSG_ALIGN(filter.flushp));
        memcpy(fn, n, n->nlmsg_len);
        fn->nlmsg_type = RTM_DELROUTE;
        fn->nlmsg_flags = NLM_F_REQUEST;
        fn->nlmsg_seq = ++filter.rth->seq;
        filter.flushp = (((char*)fn) + n->nlmsg_len) - filter.flushb;
        filter.flushed++;
        return 0;
    }

    if (n->nlmsg_type == RTM_DELROUTE) {
        fprintf(fp, "Deleted ");
    }
    if (r->rtm_type != RTN_UNICAST && !filter.type) {
        fprintf(fp, "%s ", rtnl_rtntype_n2a(r->rtm_type, b1, sizeof(b1)));
    }

    if (tb[RTA_DST]) {
        if (r->rtm_dst_len != host_len) {
            fprintf(fp, "%s/%u ", rt_addr_n2a(r->rtm_family,
                             RTA_PAYLOAD(tb[RTA_DST]),
                             RTA_DATA(tb[RTA_DST]),
                             abuf, sizeof(abuf)),
                r->rtm_dst_len
                );
        } else {
            fprintf(fp, "%s ", format_host(r->rtm_family,
                               RTA_PAYLOAD(tb[RTA_DST]),
                               RTA_DATA(tb[RTA_DST]),
                               abuf, sizeof(abuf))
                );
        }
    } else if (r->rtm_dst_len) {
        fprintf(fp, "0/%d ", r->rtm_dst_len);
    } else {
        fprintf(fp, "default ");
    }
    if (tb[RTA_SRC]) {
        if (r->rtm_src_len != host_len) {
            fprintf(fp, "from %s/%u ", rt_addr_n2a(r->rtm_family,
                             RTA_PAYLOAD(tb[RTA_SRC]),
                             RTA_DATA(tb[RTA_SRC]),
                             abuf, sizeof(abuf)),
                r->rtm_src_len
                );
        } else {
            fprintf(fp, "from %s ", format_host(r->rtm_family,
                               RTA_PAYLOAD(tb[RTA_SRC]),
                               RTA_DATA(tb[RTA_SRC]),
                               abuf, sizeof(abuf))
                );
        }
    } else if (r->rtm_src_len) {
        fprintf(fp, "from 0/%u ", r->rtm_src_len);
    }
    if (tb[RTA_GATEWAY] && filter.rvia.bitlen != host_len) {
        fprintf(fp, "via %s ",
            format_host(r->rtm_family,
                    RTA_PAYLOAD(tb[RTA_GATEWAY]),
                    RTA_DATA(tb[RTA_GATEWAY]),
                    abuf, sizeof(abuf)));
    }
    if (tb[RTA_OIF] && filter.oifmask != -1) {
        fprintf(fp, "dev %s ", ll_index_to_name(*(int*)RTA_DATA(tb[RTA_OIF])));
    }

    if (tb[RTA_PREFSRC] && filter.rprefsrc.bitlen != host_len) {
        /* Do not use format_host(). It is our local addr
           and symbolic name will not be useful.
         */
        fprintf(fp, " src %s ",
            rt_addr_n2a(r->rtm_family,
                    RTA_PAYLOAD(tb[RTA_PREFSRC]),
                    RTA_DATA(tb[RTA_PREFSRC]),
                    abuf, sizeof(abuf)));
    }
    if (tb[RTA_PRIORITY]) {
        fprintf(fp, " metric %d ", *(uint32_t*)RTA_DATA(tb[RTA_PRIORITY]));
    }
    if (r->rtm_family == AF_INET6) {
        struct rta_cacheinfo *ci = NULL;
        if (tb[RTA_CACHEINFO]) {
            ci = RTA_DATA(tb[RTA_CACHEINFO]);
        }
        if ((r->rtm_flags & RTM_F_CLONED) || (ci && ci->rta_expires)) {
            if (r->rtm_flags & RTM_F_CLONED) {
                fprintf(fp, "%c    cache ", _SL_);
            }
            if (ci->rta_expires) {
                fprintf(fp, " expires %dsec", ci->rta_expires / get_hz());
            }
            if (ci->rta_error != 0) {
                fprintf(fp, " error %d", ci->rta_error);
            }
        } else if (ci) {
            if (ci->rta_error != 0)
                fprintf(fp, " error %d", ci->rta_error);
        }
    }
    if (tb[RTA_IIF] && filter.iifmask != -1) {
        fprintf(fp, " iif %s", ll_index_to_name(*(int*)RTA_DATA(tb[RTA_IIF])));
    }
    fputc('\n', fp);
    fflush(fp);
    return 0;
}

/* Return value becomes exitcode. It's okay to not return at all */
static int iproute_modify(int cmd, unsigned flags, int argc, char **argv)
{
    static const char keywords[] ALIGN1 =
        "src\0""via\0""mtu\0""lock\0""protocol\0"USE_FEATURE_IP_RULE("table\0")
        "dev\0""oif\0""to\0";
    enum {
        ARG_src,
        ARG_via,
        ARG_mtu, PARM_lock,
        ARG_protocol,
USE_FEATURE_IP_RULE(ARG_table,)
        ARG_dev,
        ARG_oif,
        ARG_to
    };
    enum {
        gw_ok = 1 << 0,
        dst_ok = 1 << 1,
        proto_ok = 1 << 2,
        type_ok = 1 << 3
    };
    struct rtnl_handle rth;
    struct {
        struct nlmsghdr     n;
        struct rtmsg        r;
        char            buf[1024];
    } req;
    char mxbuf[256];
    struct rtattr * mxrta = (void*)mxbuf;
    unsigned mxlock = 0;
    char *d = NULL;
    smalluint ok = 0;
    int arg;

    memset(&req, 0, sizeof(req));

    req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
    req.n.nlmsg_flags = NLM_F_REQUEST|flags;
    req.n.nlmsg_type = cmd;
    req.r.rtm_family = preferred_family;
    req.r.rtm_table = RT_TABLE_MAIN;
    req.r.rtm_scope = RT_SCOPE_NOWHERE;

    if (cmd != RTM_DELROUTE) {
        req.r.rtm_protocol = RTPROT_BOOT;
        req.r.rtm_scope = RT_SCOPE_UNIVERSE;
        req.r.rtm_type = RTN_UNICAST;
    }

    mxrta->rta_type = RTA_METRICS;
    mxrta->rta_len = RTA_LENGTH(0);

    while (argc > 0) {
        arg = index_in_substrings(keywords, *argv);
        if (arg == ARG_src) {
            inet_prefix addr;
            NEXT_ARG();
            get_addr(&addr, *argv, req.r.rtm_family);
            if (req.r.rtm_family == AF_UNSPEC)
                req.r.rtm_family = addr.family;
            addattr_l(&req.n, sizeof(req), RTA_PREFSRC, &addr.data, addr.bytelen);
        } else if (arg == ARG_via) {
            inet_prefix addr;
            ok |= gw_ok;
            NEXT_ARG();
            get_addr(&addr, *argv, req.r.rtm_family);
            if (req.r.rtm_family == AF_UNSPEC) {
                req.r.rtm_family = addr.family;
            }
            addattr_l(&req.n, sizeof(req), RTA_GATEWAY, &addr.data, addr.bytelen);
        } else if (arg == ARG_mtu) {
            unsigned mtu;
            NEXT_ARG();
            if (index_in_strings(keywords, *argv) == PARM_lock) {
                mxlock |= (1<<RTAX_MTU);
                NEXT_ARG();
            }
            if (get_unsigned(&mtu, *argv, 0))
                invarg(*argv, "mtu");
            rta_addattr32(mxrta, sizeof(mxbuf), RTAX_MTU, mtu);
        } else if (arg == ARG_protocol) {
            uint32_t prot;
            NEXT_ARG();
            if (rtnl_rtprot_a2n(&prot, *argv))
                invarg(*argv, "protocol");
            req.r.rtm_protocol = prot;
            ok |= proto_ok;
#if ENABLE_FEATURE_IP_RULE
        } else if (arg == ARG_table) {
            uint32_t tid;
            NEXT_ARG();
            if (rtnl_rttable_a2n(&tid, *argv))
                invarg(*argv, "table");
            req.r.rtm_table = tid;
#endif
        } else if (arg == ARG_dev || arg == ARG_oif) {
            NEXT_ARG();
            d = *argv;
        } else {
            int type;
            inet_prefix dst;

            if (arg == ARG_to) {
                NEXT_ARG();
            }
            if ((**argv < '0' || **argv > '9')
                && rtnl_rtntype_a2n(&type, *argv) == 0) {
                NEXT_ARG();
                req.r.rtm_type = type;
                ok |= type_ok;
            }

            if (ok & dst_ok) {
                duparg2("to", *argv);
            }
            get_prefix(&dst, *argv, req.r.rtm_family);
            if (req.r.rtm_family == AF_UNSPEC) {
                req.r.rtm_family = dst.family;
            }
            req.r.rtm_dst_len = dst.bitlen;
            ok |= dst_ok;
            if (dst.bytelen) {
                addattr_l(&req.n, sizeof(req), RTA_DST, &dst.data, dst.bytelen);
            }
        }
        argc--; argv++;
    }

    xrtnl_open(&rth);

    if (d)  {
        int idx;

        ll_init_map(&rth);

        if (d) {
            idx = xll_name_to_index(d);
            addattr32(&req.n, sizeof(req), RTA_OIF, idx);
        }
    }

    if (mxrta->rta_len > RTA_LENGTH(0)) {
        if (mxlock) {
            rta_addattr32(mxrta, sizeof(mxbuf), RTAX_LOCK, mxlock);
        }
        addattr_l(&req.n, sizeof(req), RTA_METRICS, RTA_DATA(mxrta), RTA_PAYLOAD(mxrta));
    }

    if (req.r.rtm_type == RTN_LOCAL || req.r.rtm_type == RTN_NAT)
        req.r.rtm_scope = RT_SCOPE_HOST;
    else if (req.r.rtm_type == RTN_BROADCAST ||
            req.r.rtm_type == RTN_MULTICAST ||
            req.r.rtm_type == RTN_ANYCAST)
        req.r.rtm_scope = RT_SCOPE_LINK;
    else if (req.r.rtm_type == RTN_UNICAST || req.r.rtm_type == RTN_UNSPEC) {
        if (cmd == RTM_DELROUTE)
            req.r.rtm_scope = RT_SCOPE_NOWHERE;
        else if (!(ok & gw_ok))
            req.r.rtm_scope = RT_SCOPE_LINK;
    }

    if (req.r.rtm_family == AF_UNSPEC) {
        req.r.rtm_family = AF_INET;
    }

    if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0) {
        return 2;
    }

    return 0;
}

static int rtnl_rtcache_request(struct rtnl_handle *rth, int family)
{
    struct {
        struct nlmsghdr nlh;
        struct rtmsg rtm;
    } req;
    struct sockaddr_nl nladdr;

    memset(&nladdr, 0, sizeof(nladdr));
    memset(&req, 0, sizeof(req));
    nladdr.nl_family = AF_NETLINK;

    req.nlh.nlmsg_len = sizeof(req);
    req.nlh.nlmsg_type = RTM_GETROUTE;
    req.nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_REQUEST;
    req.nlh.nlmsg_pid = 0;
    req.nlh.nlmsg_seq = rth->dump = ++rth->seq;
    req.rtm.rtm_family = family;
    req.rtm.rtm_flags |= RTM_F_CLONED;

    return xsendto(rth->fd, (void*)&req, sizeof(req), (struct sockaddr*)&nladdr, sizeof(nladdr));
}

static void iproute_flush_cache(void)
{
    static const char fn[] ALIGN1 = "/proc/sys/net/ipv4/route/flush";
    int flush_fd = open_or_warn(fn, O_WRONLY);

    if (flush_fd < 0) {
        return;
    }

    if (write(flush_fd, "-1", 2) < 2) {
        bb_perror_msg("cannot flush routing cache");
        return;
    }
    close(flush_fd);
}

static void iproute_reset_filter(void)
{
    memset(&filter, 0, sizeof(filter));
    filter.mdst.bitlen = -1;
    filter.msrc.bitlen = -1;
}

/* Return value becomes exitcode. It's okay to not return at all */
static int iproute_list_or_flush(int argc, char **argv, int flush)
{
    int do_ipv6 = preferred_family;
    struct rtnl_handle rth;
    char *id = NULL;
    char *od = NULL;
    static const char keywords[] ALIGN1 =
        "protocol\0""all\0""dev\0""oif\0""iif\0""via\0""table\0""cache\0" /*all*/
        "from\0""root\0""match\0""exact\0""to\0"/*root match exact*/;
    enum {
        ARG_proto, PARM_all,
        ARG_dev,
        ARG_oif,
        ARG_iif,
        ARG_via,
        ARG_table, PARM_cache, /*PARM_all,*/
        ARG_from, PARM_root, PARM_match, PARM_exact,
        ARG_to  /*PARM_root, PARM_match, PARM_exact*/
    };
    int arg, parm;
    iproute_reset_filter();
    filter.tb = RT_TABLE_MAIN;

    if (flush && argc <= 0)
        bb_error_msg_and_die(bb_msg_requires_arg, "\"ip route flush\"");

    while (argc > 0) {
        arg = index_in_substrings(keywords, *argv);
        if (arg == ARG_proto) {
            uint32_t prot = 0;
            NEXT_ARG();
            filter.protocolmask = -1;
            if (rtnl_rtprot_a2n(&prot, *argv)) {
                if (index_in_strings(keywords, *argv) != PARM_all)
                    invarg(*argv, "protocol");
                prot = 0;
                filter.protocolmask = 0;
            }
            filter.protocol = prot;
        } else if (arg == ARG_dev || arg == ARG_oif) {
            NEXT_ARG();
            od = *argv;
        } else if (arg == ARG_iif) {
            NEXT_ARG();
            id = *argv;
        } else if (arg == ARG_via) {
            NEXT_ARG();
            get_prefix(&filter.rvia, *argv, do_ipv6);
        } else if (arg == ARG_table) {
            NEXT_ARG();
            parm = index_in_substrings(keywords, *argv);
            if (parm == PARM_cache)
                filter.tb = -1;
            else if (parm == PARM_all)
                filter.tb = 0;
            else
                invarg(*argv, "table");
        } else if (arg == ARG_from) {
            NEXT_ARG();
            parm = index_in_substrings(keywords, *argv);
            if (parm == PARM_root) {
                NEXT_ARG();
                get_prefix(&filter.rsrc, *argv, do_ipv6);
            } else if (parm == PARM_match) {
                NEXT_ARG();
                get_prefix(&filter.msrc, *argv, do_ipv6);
            } else {
                if (parm == PARM_exact)
                    NEXT_ARG();
                get_prefix(&filter.msrc, *argv, do_ipv6);
                filter.rsrc = filter.msrc;
            }
        } else {
            /* parm = arg; // would be more plausible, we reuse arg here */
            if (arg == ARG_to) {
                NEXT_ARG();
                arg = index_in_substrings(keywords, *argv);
            }
            if (arg == PARM_root) {
                NEXT_ARG();
                get_prefix(&filter.rdst, *argv, do_ipv6);
            } else if (arg == PARM_match) {
                NEXT_ARG();
                get_prefix(&filter.mdst, *argv, do_ipv6);
            } else {
                if (arg == PARM_exact)
                    NEXT_ARG();
                get_prefix(&filter.mdst, *argv, do_ipv6);
                filter.rdst = filter.mdst;
            }
        }
        argc--;
        argv++;
    }

    if (do_ipv6 == AF_UNSPEC && filter.tb) {
        do_ipv6 = AF_INET;
    }

    xrtnl_open(&rth);

    ll_init_map(&rth);

    if (id || od)  {
        int idx;

        if (id) {
            idx = xll_name_to_index(id);
            filter.iif = idx;
            filter.iifmask = -1;
        }
        if (od) {
            idx = xll_name_to_index(od);
            filter.oif = idx;
            filter.oifmask = -1;
        }
    }

    if (flush) {
        char flushb[4096-512];

        if (filter.tb == -1) {
            if (do_ipv6 != AF_INET6)
                iproute_flush_cache();
            if (do_ipv6 == AF_INET)
                return 0;
        }

        filter.flushb = flushb;
        filter.flushp = 0;
        filter.flushe = sizeof(flushb);
        filter.rth = &rth;

        for (;;) {
            xrtnl_wilddump_request(&rth, do_ipv6, RTM_GETROUTE);
            filter.flushed = 0;
            xrtnl_dump_filter(&rth, print_route, stdout);
            if (filter.flushed == 0)
                return 0;
            if (flush_update())
                return 1;
        }
    }

    if (filter.tb != -1) {
        xrtnl_wilddump_request(&rth, do_ipv6, RTM_GETROUTE);
    } else if (rtnl_rtcache_request(&rth, do_ipv6) < 0) {
        bb_perror_msg_and_die("cannot send dump request");
    }
    xrtnl_dump_filter(&rth, print_route, stdout);

    return 0;
}


/* Return value becomes exitcode. It's okay to not return at all */
static int iproute_get(int argc, char **argv)
{
    struct rtnl_handle rth;
    struct {
        struct nlmsghdr n;
        struct rtmsg    r;
        char            buf[1024];
    } req;
    char *idev = NULL;
    char *odev = NULL;
    bool connected = 0;
    bool from_ok = 0;
    static const char options[] ALIGN1 =
        "from\0""iif\0""oif\0""dev\0""notify\0""connected\0""to\0";

    memset(&req, 0, sizeof(req));

    iproute_reset_filter();

    req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
    req.n.nlmsg_flags = NLM_F_REQUEST;
    req.n.nlmsg_type = RTM_GETROUTE;
    req.r.rtm_family = preferred_family;
    req.r.rtm_table = 0;
    req.r.rtm_protocol = 0;
    req.r.rtm_scope = 0;
    req.r.rtm_type = 0;
    req.r.rtm_src_len = 0;
    req.r.rtm_dst_len = 0;
    req.r.rtm_tos = 0;

    while (argc > 0) {
        switch (index_in_strings(options, *argv)) {
            case 0: /* from */
            {
                inet_prefix addr;
                NEXT_ARG();
                from_ok = 1;
                get_prefix(&addr, *argv, req.r.rtm_family);
                if (req.r.rtm_family == AF_UNSPEC) {
                    req.r.rtm_family = addr.family;
                }
                if (addr.bytelen) {
                    addattr_l(&req.n, sizeof(req), RTA_SRC, &addr.data, addr.bytelen);
                }
                req.r.rtm_src_len = addr.bitlen;
                break;
            }
            case 1: /* iif */
                NEXT_ARG();
                idev = *argv;
                break;
            case 2: /* oif */
            case 3: /* dev */
                NEXT_ARG();
                odev = *argv;
                break;
            case 4: /* notify */
                req.r.rtm_flags |= RTM_F_NOTIFY;
                break;
            case 5: /* connected */
                connected = 1;
                break;
            case 6: /* to */
                NEXT_ARG();
            default:
            {
                inet_prefix addr;
                get_prefix(&addr, *argv, req.r.rtm_family);
                if (req.r.rtm_family == AF_UNSPEC) {
                    req.r.rtm_family = addr.family;
                }
                if (addr.bytelen) {
                    addattr_l(&req.n, sizeof(req), RTA_DST, &addr.data, addr.bytelen);
                }
                req.r.rtm_dst_len = addr.bitlen;
            }
            argc--; argv++;
        }
    }

    if (req.r.rtm_dst_len == 0) {
        bb_error_msg_and_die("need at least destination address");
    }

    xrtnl_open(&rth);

    ll_init_map(&rth);

    if (idev || odev)  {
        int idx;

        if (idev) {
            idx = xll_name_to_index(idev);
            addattr32(&req.n, sizeof(req), RTA_IIF, idx);
        }
        if (odev) {
            idx = xll_name_to_index(odev);
            addattr32(&req.n, sizeof(req), RTA_OIF, idx);
        }
    }

    if (req.r.rtm_family == AF_UNSPEC) {
        req.r.rtm_family = AF_INET;
    }

    if (rtnl_talk(&rth, &req.n, 0, 0, &req.n, NULL, NULL) < 0) {
        return 2;
    }

    if (connected && !from_ok) {
        struct rtmsg *r = NLMSG_DATA(&req.n);
        int len = req.n.nlmsg_len;
        struct rtattr * tb[RTA_MAX+1];

        print_route(NULL, &req.n, (void*)stdout);

        if (req.n.nlmsg_type != RTM_NEWROUTE) {
            bb_error_msg_and_die("not a route?");
        }
        len -= NLMSG_LENGTH(sizeof(*r));
        if (len < 0) {
            bb_error_msg_and_die("wrong len %d", len);
        }

        memset(tb, 0, sizeof(tb));
        parse_rtattr(tb, RTA_MAX, RTM_RTA(r), len);

        if (tb[RTA_PREFSRC]) {
            tb[RTA_PREFSRC]->rta_type = RTA_SRC;
            r->rtm_src_len = 8*RTA_PAYLOAD(tb[RTA_PREFSRC]);
        } else if (!tb[RTA_SRC]) {
            bb_error_msg_and_die("failed to connect the route");
        }
        if (!odev && tb[RTA_OIF]) {
            tb[RTA_OIF]->rta_type = 0;
        }
        if (tb[RTA_GATEWAY]) {
            tb[RTA_GATEWAY]->rta_type = 0;
        }
        if (!idev && tb[RTA_IIF]) {
            tb[RTA_IIF]->rta_type = 0;
        }
        req.n.nlmsg_flags = NLM_F_REQUEST;
        req.n.nlmsg_type = RTM_GETROUTE;

        if (rtnl_talk(&rth, &req.n, 0, 0, &req.n, NULL, NULL) < 0) {
            return 2;
        }
    }
    print_route(NULL, &req.n, (void*)stdout);
    return 0;
}

/* Return value becomes exitcode. It's okay to not return at all */
int do_iproute(int argc, char **argv)
{
    static const char ip_route_commands[] ALIGN1 =
    /*0-3*/ "add\0""append\0""change\0""chg\0"
    /*4-7*/ "delete\0""get\0""list\0""show\0"
    /*8..*/ "prepend\0""replace\0""test\0""flush\0";
    int command_num = 6;
    unsigned flags = 0;
    int cmd = RTM_NEWROUTE;

    /* "Standard" 'ip r a' treats 'a' as 'add', not 'append' */
    /* It probably means that it is using "first match" rule */
    if (*argv) {
        command_num = index_in_substrings(ip_route_commands, *argv);
    }
    switch (command_num) {
        case 0: /* add */
            flags = NLM_F_CREATE|NLM_F_EXCL;
            break;
        case 1: /* append */
            flags = NLM_F_CREATE|NLM_F_APPEND;
            break;
        case 2: /* change */
        case 3: /* chg */
            flags = NLM_F_REPLACE;
            break;
        case 4: /* delete */
            cmd = RTM_DELROUTE;
            break;
        case 5: /* get */
            return iproute_get(argc-1, argv+1);
        case 6: /* list */
        case 7: /* show */
            return iproute_list_or_flush(argc-1, argv+1, 0);
        case 8: /* prepend */
            flags = NLM_F_CREATE;
        case 9: /* replace */
            flags = NLM_F_CREATE|NLM_F_REPLACE;
        case 10: /* test */
            flags = NLM_F_EXCL;
        case 11: /* flush */
            return iproute_list_or_flush(argc-1, argv+1, 1);
        default:
            bb_error_msg_and_die("unknown command %s", *argv);
    }

    return iproute_modify(cmd, flags, argc-1, argv+1);
}