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

/* vi: set sw=4 ts=4: */
/*
 * iprule.c     "ip rule".
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 *
 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 *
 * Changes:
 *
 * Rani Assaf <rani@magic.metawire.com> 980929: resolve addresses
 * initially integrated into busybox by Bernhard Fischer
 */

#include <syslog.h>
//#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <arpa/inet.h>

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

/*
static void usage(void) __attribute__((noreturn));

static void usage(void)
{
    fprintf(stderr, "Usage: ip rule [ list | add | del ] SELECTOR ACTION\n");
    fprintf(stderr, "SELECTOR := [ from PREFIX ] [ to PREFIX ] [ tos TOS ] [ fwmark FWMARK ]\n");
    fprintf(stderr, "            [ dev STRING ] [ pref NUMBER ]\n");
    fprintf(stderr, "ACTION := [ table TABLE_ID ] [ nat ADDRESS ]\n");
    fprintf(stderr, "          [ prohibit | reject | unreachable ]\n");
    fprintf(stderr, "          [ realms [SRCREALM/]DSTREALM ]\n");
    fprintf(stderr, "TABLE_ID := [ local | main | default | NUMBER ]\n");
    exit(-1);
}
*/

static int print_rule(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;
    int host_len = -1;
    struct rtattr * tb[RTA_MAX+1];
    char abuf[256];
    SPRINT_BUF(b1);

    if (n->nlmsg_type != RTM_NEWRULE)
        return 0;

    len -= NLMSG_LENGTH(sizeof(*r));
    if (len < 0)
        return -1;

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

    if (r->rtm_family == AF_INET)
        host_len = 32;
    else if (r->rtm_family == AF_INET6)
        host_len = 128;
/*  else if (r->rtm_family == AF_DECnet)
        host_len = 16;
    else if (r->rtm_family == AF_IPX)
        host_len = 80;
*/
    if (tb[RTA_PRIORITY])
        fprintf(fp, "%u:\t", *(unsigned*)RTA_DATA(tb[RTA_PRIORITY]));
    else
        fprintf(fp, "0:\t");

    fprintf(fp, "from ");
    if (tb[RTA_SRC]) {
        if (r->rtm_src_len != host_len) {
            fprintf(fp, "%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, "%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, "0/%d", r->rtm_src_len);
    } else {
        fprintf(fp, "all");
    }
    fprintf(fp, " ");

    if (tb[RTA_DST]) {
        if (r->rtm_dst_len != host_len) {
            fprintf(fp, "to %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, "to %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, "to 0/%d ", r->rtm_dst_len);
    }

    if (r->rtm_tos) {
        fprintf(fp, "tos %s ", rtnl_dsfield_n2a(r->rtm_tos, b1, sizeof(b1)));
    }
    if (tb[RTA_PROTOINFO]) {
        fprintf(fp, "fwmark %#x ", *(uint32_t*)RTA_DATA(tb[RTA_PROTOINFO]));
    }

    if (tb[RTA_IIF]) {
        fprintf(fp, "iif %s ", (char*)RTA_DATA(tb[RTA_IIF]));
    }

    if (r->rtm_table)
        fprintf(fp, "lookup %s ", rtnl_rttable_n2a(r->rtm_table, b1, sizeof(b1)));

    if (tb[RTA_FLOW]) {
        uint32_t to = *(uint32_t*)RTA_DATA(tb[RTA_FLOW]);
        uint32_t from = to>>16;
        to &= 0xFFFF;
        if (from) {
            fprintf(fp, "realms %s/",
                rtnl_rtrealm_n2a(from, b1, sizeof(b1)));
        }
        fprintf(fp, "%s ",
            rtnl_rtrealm_n2a(to, b1, sizeof(b1)));
    }

    if (r->rtm_type == RTN_NAT) {
        if (tb[RTA_GATEWAY]) {
            fprintf(fp, "map-to %s ",
                format_host(r->rtm_family,
                        RTA_PAYLOAD(tb[RTA_GATEWAY]),
                        RTA_DATA(tb[RTA_GATEWAY]),
                        abuf, sizeof(abuf)));
        } else
            fprintf(fp, "masquerade");
    } else if (r->rtm_type != RTN_UNICAST)
        fprintf(fp, "%s", rtnl_rtntype_n2a(r->rtm_type, b1, sizeof(b1)));

    fputc('\n', fp);
    fflush(fp);
    return 0;
}

/* Return value becomes exitcode. It's okay to not return at all */
static int iprule_list(int argc, char **argv)
{
    struct rtnl_handle rth;
    int af = preferred_family;

    if (af == AF_UNSPEC)
        af = AF_INET;

    if (argc > 0) {
        //bb_error_msg("\"rule show\" needs no arguments");
        bb_warn_ignoring_args(argc);
        return -1;
    }

    xrtnl_open(&rth);

    xrtnl_wilddump_request(&rth, af, RTM_GETRULE);
    xrtnl_dump_filter(&rth, print_rule, stdout);

    return 0;
}

/* Return value becomes exitcode. It's okay to not return at all */
static int iprule_modify(int cmd, int argc, char **argv)
{
    static const char keywords[] ALIGN1 =
        "from\0""to\0""preference\0""order\0""priority\0"
        "tos\0""fwmark\0""realms\0""table\0""lookup\0""dev\0"
        "iif\0""nat\0""map-to\0""type\0""help\0";
    enum {
        ARG_from = 1, ARG_to, ARG_preference, ARG_order, ARG_priority,
        ARG_tos, ARG_fwmark, ARG_realms, ARG_table, ARG_lookup, ARG_dev,
        ARG_iif, ARG_nat, ARG_map_to, ARG_type, ARG_help
    };
    bool table_ok = 0;
    struct rtnl_handle rth;
    struct {
        struct nlmsghdr n;
        struct rtmsg    r;
        char        buf[1024];
    } req;
    smalluint key;

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

    req.n.nlmsg_type = cmd;
    req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
    req.n.nlmsg_flags = NLM_F_REQUEST;
    req.r.rtm_family = preferred_family;
    req.r.rtm_protocol = RTPROT_BOOT;
    req.r.rtm_scope = RT_SCOPE_UNIVERSE;
    req.r.rtm_table = 0;
    req.r.rtm_type = RTN_UNSPEC;

    if (cmd == RTM_NEWRULE) {
        req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;
        req.r.rtm_type = RTN_UNICAST;
    }

    while (argc > 0) {
        key = index_in_substrings(keywords, *argv) + 1;
        if (key == 0) /* no match found in keywords array, bail out. */
            bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name);
        if (key == ARG_from) {
            inet_prefix dst;
            NEXT_ARG();
            get_prefix(&dst, *argv, req.r.rtm_family);
            req.r.rtm_src_len = dst.bitlen;
            addattr_l(&req.n, sizeof(req), RTA_SRC, &dst.data, dst.bytelen);
        } else if (key == ARG_to) {
            inet_prefix dst;
            NEXT_ARG();
            get_prefix(&dst, *argv, req.r.rtm_family);
            req.r.rtm_dst_len = dst.bitlen;
            addattr_l(&req.n, sizeof(req), RTA_DST, &dst.data, dst.bytelen);
        } else if (key == ARG_preference ||
               key == ARG_order ||
               key == ARG_priority) {
            uint32_t pref;
            NEXT_ARG();
            if (get_u32(&pref, *argv, 0))
                invarg(*argv, "preference");
            addattr32(&req.n, sizeof(req), RTA_PRIORITY, pref);
        } else if (key == ARG_tos) {
            uint32_t tos;
            NEXT_ARG();
            if (rtnl_dsfield_a2n(&tos, *argv))
                invarg(*argv, "TOS");
            req.r.rtm_tos = tos;
        } else if (key == ARG_fwmark) {
            uint32_t fwmark;
            NEXT_ARG();
            if (get_u32(&fwmark, *argv, 0))
                invarg(*argv, "fwmark");
            addattr32(&req.n, sizeof(req), RTA_PROTOINFO, fwmark);
        } else if (key == ARG_realms) {
            uint32_t realm;
            NEXT_ARG();
            if (get_rt_realms(&realm, *argv))
                invarg(*argv, "realms");
            addattr32(&req.n, sizeof(req), RTA_FLOW, realm);
        } else if (key == ARG_table ||
               key == ARG_lookup) {
            uint32_t tid;
            NEXT_ARG();
            if (rtnl_rttable_a2n(&tid, *argv))
                invarg(*argv, "table ID");
            req.r.rtm_table = tid;
            table_ok = 1;
        } else if (key == ARG_dev ||
               key == ARG_iif) {
            NEXT_ARG();
            addattr_l(&req.n, sizeof(req), RTA_IIF, *argv, strlen(*argv)+1);
        } else if (key == ARG_nat ||
               key == ARG_map_to) {
            NEXT_ARG();
            addattr32(&req.n, sizeof(req), RTA_GATEWAY, get_addr32(*argv));
            req.r.rtm_type = RTN_NAT;
        } else {
            int type;

            if (key == ARG_type) {
                NEXT_ARG();
            }
            if (key == ARG_help)
                bb_show_usage();
            if (rtnl_rtntype_a2n(&type, *argv))
                invarg(*argv, "type");
            req.r.rtm_type = type;
        }
        argc--;
        argv++;
    }

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

    if (!table_ok && cmd == RTM_NEWRULE)
        req.r.rtm_table = RT_TABLE_MAIN;

    xrtnl_open(&rth);

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

    return 0;
}

/* Return value becomes exitcode. It's okay to not return at all */
int do_iprule(int argc, char **argv)
{
    static const char ip_rule_commands[] ALIGN1 =
        "add\0""delete\0""list\0""show\0";
    int cmd = 2; /* list */

    if (argc < 1)
        return iprule_list(0, NULL);
    if (*argv)
        cmd = index_in_substrings(ip_rule_commands, *argv);

    switch (cmd) {
        case 0: /* add */
            cmd = RTM_NEWRULE;
            break;
        case 1: /* delete */
            cmd = RTM_DELRULE;
            break;
        case 2: /* list */
        case 3: /* show */
            return iprule_list(argc-1, argv+1);
            break;
        default:
            bb_error_msg_and_die("unknown command %s", *argv);
    }
    return iprule_modify(cmd, argc-1, argv+1);
}