busybox/networking/libiproute/iprule.c
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   1/* vi: set sw=4 ts=4: */
   2/*
   3 * This program is free software; you can redistribute it and/or
   4 * modify it under the terms of the GNU General Public License
   5 * as published by the Free Software Foundation; either version
   6 * 2 of the License, or (at your option) any later version.
   7 *
   8 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
   9 *
  10 * Changes:
  11 *
  12 * Rani Assaf <rani@magic.metawire.com> 980929: resolve addresses
  13 * initially integrated into busybox by Bernhard Reutner-Fischer
  14 */
  15
  16#include <netinet/in.h>
  17#include <netinet/ip.h>
  18#include <arpa/inet.h>
  19
  20#include "ip_common.h"  /* #include "libbb.h" is inside */
  21#include "rt_names.h"
  22#include "utils.h"
  23
  24/*
  25static void usage(void) __attribute__((noreturn));
  26
  27static void usage(void)
  28{
  29        fprintf(stderr, "Usage: ip rule [ list | add | del ] SELECTOR ACTION\n");
  30        fprintf(stderr, "SELECTOR := [ from PREFIX ] [ to PREFIX ] [ tos TOS ] [ fwmark FWMARK ]\n");
  31        fprintf(stderr, "            [ dev STRING ] [ pref NUMBER ]\n");
  32        fprintf(stderr, "ACTION := [ table TABLE_ID ] [ nat ADDRESS ]\n");
  33        fprintf(stderr, "          [ prohibit | reject | unreachable ]\n");
  34        fprintf(stderr, "          [ realms [SRCREALM/]DSTREALM ]\n");
  35        fprintf(stderr, "TABLE_ID := [ local | main | default | NUMBER ]\n");
  36        exit(-1);
  37}
  38*/
  39
  40static int FAST_FUNC print_rule(const struct sockaddr_nl *who UNUSED_PARAM,
  41                                        struct nlmsghdr *n, void *arg UNUSED_PARAM)
  42{
  43        struct rtmsg *r = NLMSG_DATA(n);
  44        int len = n->nlmsg_len;
  45        int host_len = -1;
  46        struct rtattr * tb[RTA_MAX+1];
  47
  48        if (n->nlmsg_type != RTM_NEWRULE)
  49                return 0;
  50
  51        len -= NLMSG_LENGTH(sizeof(*r));
  52        if (len < 0)
  53                return -1;
  54
  55        memset(tb, 0, sizeof(tb));
  56        parse_rtattr(tb, RTA_MAX, RTM_RTA(r), len);
  57
  58        if (r->rtm_family == AF_INET)
  59                host_len = 32;
  60        else if (r->rtm_family == AF_INET6)
  61                host_len = 128;
  62/*      else if (r->rtm_family == AF_DECnet)
  63                host_len = 16;
  64        else if (r->rtm_family == AF_IPX)
  65                host_len = 80;
  66*/
  67        printf("%u:\t", tb[RTA_PRIORITY] ?
  68                                        *(unsigned*)RTA_DATA(tb[RTA_PRIORITY])
  69                                        : 0);
  70        printf("from ");
  71        if (tb[RTA_SRC]) {
  72                if (r->rtm_src_len != host_len) {
  73                        printf("%s/%u",
  74                                rt_addr_n2a(r->rtm_family, RTA_DATA(tb[RTA_SRC])),
  75                                r->rtm_src_len
  76                        );
  77                } else {
  78                        fputs(format_host(r->rtm_family,
  79                                                RTA_PAYLOAD(tb[RTA_SRC]),
  80                                                RTA_DATA(tb[RTA_SRC])),
  81                                stdout
  82                        );
  83                }
  84        } else if (r->rtm_src_len) {
  85                printf("0/%d", r->rtm_src_len);
  86        } else {
  87                printf("all");
  88        }
  89        bb_putchar(' ');
  90
  91        if (tb[RTA_DST]) {
  92                if (r->rtm_dst_len != host_len) {
  93                        printf("to %s/%u ", rt_addr_n2a(r->rtm_family,
  94                                                         RTA_DATA(tb[RTA_DST])),
  95                                r->rtm_dst_len
  96                                );
  97                } else {
  98                        printf("to %s ", format_host(r->rtm_family,
  99                                                       RTA_PAYLOAD(tb[RTA_DST]),
 100                                                       RTA_DATA(tb[RTA_DST])));
 101                }
 102        } else if (r->rtm_dst_len) {
 103                printf("to 0/%d ", r->rtm_dst_len);
 104        }
 105
 106        if (r->rtm_tos) {
 107                printf("tos %s ", rtnl_dsfield_n2a(r->rtm_tos));
 108        }
 109        if (tb[RTA_PROTOINFO]) {
 110                printf("fwmark %#x ", *(uint32_t*)RTA_DATA(tb[RTA_PROTOINFO]));
 111        }
 112
 113        if (tb[RTA_IIF]) {
 114                printf("iif %s ", (char*)RTA_DATA(tb[RTA_IIF]));
 115        }
 116
 117        if (r->rtm_table)
 118                printf("lookup %s ", rtnl_rttable_n2a(r->rtm_table));
 119
 120        if (tb[RTA_FLOW]) {
 121                uint32_t to = *(uint32_t*)RTA_DATA(tb[RTA_FLOW]);
 122                uint32_t from = to>>16;
 123                to &= 0xFFFF;
 124                if (from) {
 125                        printf("realms %s/",
 126                                rtnl_rtrealm_n2a(from));
 127                }
 128                printf("%s ",
 129                        rtnl_rtrealm_n2a(to));
 130        }
 131
 132        if (r->rtm_type == RTN_NAT) {
 133                if (tb[RTA_GATEWAY]) {
 134                        printf("map-to %s ",
 135                                format_host(r->rtm_family,
 136                                            RTA_PAYLOAD(tb[RTA_GATEWAY]),
 137                                            RTA_DATA(tb[RTA_GATEWAY]))
 138                        );
 139                } else
 140                        printf("masquerade");
 141        } else if (r->rtm_type != RTN_UNICAST)
 142                fputs(rtnl_rtntype_n2a(r->rtm_type), stdout);
 143
 144        bb_putchar('\n');
 145        /*fflush_all();*/
 146        return 0;
 147}
 148
 149/* Return value becomes exitcode. It's okay to not return at all */
 150static int iprule_list(char **argv)
 151{
 152        struct rtnl_handle rth;
 153        int af = preferred_family;
 154
 155        if (af == AF_UNSPEC)
 156                af = AF_INET;
 157
 158        if (*argv) {
 159                //bb_error_msg("\"rule show\" needs no arguments");
 160                bb_warn_ignoring_args(*argv);
 161                return -1;
 162        }
 163
 164        xrtnl_open(&rth);
 165
 166        xrtnl_wilddump_request(&rth, af, RTM_GETRULE);
 167        xrtnl_dump_filter(&rth, print_rule, NULL);
 168
 169        return 0;
 170}
 171
 172/* Return value becomes exitcode. It's okay to not return at all */
 173static int iprule_modify(int cmd, char **argv)
 174{
 175        static const char keywords[] ALIGN1 =
 176                "from\0""to\0""preference\0""order\0""priority\0"
 177                "tos\0""fwmark\0""realms\0""table\0""lookup\0""dev\0"
 178                "iif\0""nat\0""map-to\0""type\0""help\0";
 179        enum {
 180                ARG_from = 1, ARG_to, ARG_preference, ARG_order, ARG_priority,
 181                ARG_tos, ARG_fwmark, ARG_realms, ARG_table, ARG_lookup, ARG_dev,
 182                ARG_iif, ARG_nat, ARG_map_to, ARG_type, ARG_help
 183        };
 184        bool table_ok = 0;
 185        struct rtnl_handle rth;
 186        struct {
 187                struct nlmsghdr n;
 188                struct rtmsg    r;
 189                char            buf[1024];
 190        } req;
 191        smalluint key;
 192
 193        memset(&req, 0, sizeof(req));
 194
 195        req.n.nlmsg_type = cmd;
 196        req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
 197        req.n.nlmsg_flags = NLM_F_REQUEST;
 198        req.r.rtm_family = preferred_family;
 199        req.r.rtm_protocol = RTPROT_BOOT;
 200        req.r.rtm_scope = RT_SCOPE_UNIVERSE;
 201        req.r.rtm_table = 0;
 202        req.r.rtm_type = RTN_UNSPEC;
 203
 204        if (cmd == RTM_NEWRULE) {
 205                req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;
 206                req.r.rtm_type = RTN_UNICAST;
 207        }
 208
 209        while (*argv) {
 210                key = index_in_substrings(keywords, *argv) + 1;
 211                if (key == 0) /* no match found in keywords array, bail out. */
 212                        invarg_1_to_2(*argv, applet_name);
 213                if (key == ARG_from) {
 214                        inet_prefix dst;
 215                        NEXT_ARG();
 216                        get_prefix(&dst, *argv, req.r.rtm_family);
 217                        req.r.rtm_src_len = dst.bitlen;
 218                        addattr_l(&req.n, sizeof(req), RTA_SRC, &dst.data, dst.bytelen);
 219                } else if (key == ARG_to) {
 220                        inet_prefix dst;
 221                        NEXT_ARG();
 222                        get_prefix(&dst, *argv, req.r.rtm_family);
 223                        req.r.rtm_dst_len = dst.bitlen;
 224                        addattr_l(&req.n, sizeof(req), RTA_DST, &dst.data, dst.bytelen);
 225                } else if (key == ARG_preference ||
 226                           key == ARG_order ||
 227                           key == ARG_priority
 228                ) {
 229                        uint32_t pref;
 230                        NEXT_ARG();
 231                        pref = get_u32(*argv, "preference");
 232                        addattr32(&req.n, sizeof(req), RTA_PRIORITY, pref);
 233                } else if (key == ARG_tos) {
 234                        uint32_t tos;
 235                        NEXT_ARG();
 236                        if (rtnl_dsfield_a2n(&tos, *argv))
 237                                invarg_1_to_2(*argv, "TOS");
 238                        req.r.rtm_tos = tos;
 239                } else if (key == ARG_fwmark) {
 240                        uint32_t fwmark;
 241                        NEXT_ARG();
 242                        fwmark = get_u32(*argv, "fwmark");
 243                        addattr32(&req.n, sizeof(req), RTA_PROTOINFO, fwmark);
 244                } else if (key == ARG_realms) {
 245                        uint32_t realm;
 246                        NEXT_ARG();
 247                        if (get_rt_realms(&realm, *argv))
 248                                invarg_1_to_2(*argv, "realms");
 249                        addattr32(&req.n, sizeof(req), RTA_FLOW, realm);
 250                } else if (key == ARG_table ||
 251                           key == ARG_lookup
 252                ) {
 253                        uint32_t tid;
 254                        NEXT_ARG();
 255                        if (rtnl_rttable_a2n(&tid, *argv))
 256                                invarg_1_to_2(*argv, "table ID");
 257                        req.r.rtm_table = tid;
 258                        table_ok = 1;
 259                } else if (key == ARG_dev ||
 260                           key == ARG_iif
 261                ) {
 262                        NEXT_ARG();
 263                        addattr_l(&req.n, sizeof(req), RTA_IIF, *argv, strlen(*argv)+1);
 264                } else if (key == ARG_nat ||
 265                           key == ARG_map_to
 266                ) {
 267                        NEXT_ARG();
 268                        addattr32(&req.n, sizeof(req), RTA_GATEWAY, get_addr32(*argv));
 269                        req.r.rtm_type = RTN_NAT;
 270                } else {
 271                        int type;
 272
 273                        if (key == ARG_type) {
 274                                NEXT_ARG();
 275                        }
 276                        if (key == ARG_help)
 277                                bb_show_usage();
 278                        if (rtnl_rtntype_a2n(&type, *argv))
 279                                invarg_1_to_2(*argv, "type");
 280                        req.r.rtm_type = type;
 281                }
 282                argv++;
 283        }
 284
 285        if (req.r.rtm_family == AF_UNSPEC)
 286                req.r.rtm_family = AF_INET;
 287
 288        if (!table_ok && cmd == RTM_NEWRULE)
 289                req.r.rtm_table = RT_TABLE_MAIN;
 290
 291        xrtnl_open(&rth);
 292
 293        if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
 294                return 2;
 295
 296        return 0;
 297}
 298
 299/* Return value becomes exitcode. It's okay to not return at all */
 300int FAST_FUNC do_iprule(char **argv)
 301{
 302        static const char ip_rule_commands[] ALIGN1 =
 303                "add\0""delete\0""list\0""show\0";
 304        if (*argv) {
 305                int cmd = index_in_substrings(ip_rule_commands, *argv);
 306                if (cmd < 0)
 307                        invarg_1_to_2(*argv, applet_name);
 308                argv++;
 309                if (cmd < 2)
 310                        return iprule_modify((cmd == 0) ? RTM_NEWRULE : RTM_DELRULE, argv);
 311        }
 312        return iprule_list(argv);
 313}
 314