ip/iprule.c

   1 /*
   2  * iprule.c             "ip rule".
   3  *
   4  *              This program is free software; you can redistribute it and/or
   5  *              modify it under the terms of the GNU General Public License
   6  *              as published by the Free Software Foundation; either version
   7  *              2 of the License, or (at your option) any later version.
   8  *
   9  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  10  *
  11  */
  12
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <unistd.h>
  16 #include <syslog.h>
  17 #include <fcntl.h>
  18 #include <sys/socket.h>
  19 #include <netinet/in.h>
  20 #include <netinet/ip.h>
  21 #include <arpa/inet.h>
  22 #include <string.h>
  23 #include <linux/fib_rules.h>
  24
  25 #include "rt_names.h"
  26 #include "utils.h"
  27 #include "ip_common.h"
  28
  29 extern struct rtnl_handle rth;
  30
  31 static void usage(void) __attribute__((noreturn));
  32
  33 static void usage(void)
  34 {
  35         fprintf(stderr, "Usage: ip rule [ list | add | del | flush ] SELECTOR ACTION\n");
  36         fprintf(stderr, "SELECTOR := [ not ] [ from PREFIX ] [ to PREFIX ] [ tos TOS ] [ fwmark FWMARK[/MASK] ]\n");
  37         fprintf(stderr, "            [ iif STRING ] [ oif STRING ] [ pref NUMBER ]\n");
  38         fprintf(stderr, "ACTION := [ table TABLE_ID ]\n");
  39         fprintf(stderr, "          [ prohibit | reject | unreachable ]\n");
  40         fprintf(stderr, "          [ realms [SRCREALM/]DSTREALM ]\n");
  41         fprintf(stderr, "          [ goto NUMBER ]\n");
  42         fprintf(stderr, "          SUPPRESSOR\n");
  43         fprintf(stderr, "SUPPRESSOR := [ suppress_prefixlength NUMBER ]\n");
  44         fprintf(stderr, "              [ suppress_ifgroup DEVGROUP ]\n");
  45         fprintf(stderr, "TABLE_ID := [ local | main | default | NUMBER ]\n");
  46         exit(-1);
  47 }
  48
  49 int print_rule(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
  50 {
  51         FILE *fp = (FILE*)arg;
  52         struct rtmsg *r = NLMSG_DATA(n);
  53         int len = n->nlmsg_len;
  54         int host_len = -1;
  55         __u32 table;
  56         struct rtattr * tb[FRA_MAX+1];
  57         char abuf[256];
  58         SPRINT_BUF(b1);
  59
  60         if (n->nlmsg_type != RTM_NEWRULE && n->nlmsg_type != RTM_DELRULE)
  61                 return 0;
  62
  63         len -= NLMSG_LENGTH(sizeof(*r));
  64         if (len < 0)
  65                 return -1;
  66
  67         parse_rtattr(tb, FRA_MAX, RTM_RTA(r), len);
  68
  69         if (r->rtm_family == AF_INET)
  70                 host_len = 32;
  71         else if (r->rtm_family == AF_INET6)
  72                 host_len = 128;
  73         else if (r->rtm_family == AF_DECnet)
  74                 host_len = 16;
  75         else if (r->rtm_family == AF_IPX)
  76                 host_len = 80;
  77
  78         if (n->nlmsg_type == RTM_DELRULE)
  79                 fprintf(fp, "Deleted ");
  80
  81         if (tb[FRA_PRIORITY])
  82                 fprintf(fp, "%u:\t", *(unsigned*)RTA_DATA(tb[FRA_PRIORITY]));
  83         else
  84                 fprintf(fp, "0:\t");
  85
  86         if (r->rtm_flags & FIB_RULE_INVERT)
  87                 fprintf(fp, "not ");
  88
  89         if (tb[FRA_SRC]) {
  90                 if (r->rtm_src_len != host_len) {
  91                         fprintf(fp, "from %s/%u ", rt_addr_n2a(r->rtm_family,
  92                                                          RTA_DATA(tb[FRA_SRC]),
  93                                                          abuf, sizeof(abuf)),
  94                                 r->rtm_src_len
  95                                 );
  96                 } else {
  97                         fprintf(fp, "from %s ", format_host(r->rtm_family,
  98                                                        RTA_PAYLOAD(tb[FRA_SRC]),
  99                                                        RTA_DATA(tb[FRA_SRC]),
 100                                                        abuf, sizeof(abuf))
 101                                 );
 102                 }
 103         } else if (r->rtm_src_len) {
 104                 fprintf(fp, "from 0/%d ", r->rtm_src_len);
 105         } else {
 106                 fprintf(fp, "from all ");
 107         }
 108
 109         if (tb[FRA_DST]) {
 110                 if (r->rtm_dst_len != host_len) {
 111                         fprintf(fp, "to %s/%u ", rt_addr_n2a(r->rtm_family,
 112                                                          RTA_DATA(tb[FRA_DST]),
 113                                                          abuf, sizeof(abuf)),
 114                                 r->rtm_dst_len
 115                                 );
 116                 } else {
 117                         fprintf(fp, "to %s ", format_host(r->rtm_family,
 118                                                        RTA_PAYLOAD(tb[FRA_DST]),
 119                                                        RTA_DATA(tb[FRA_DST]),
 120                                                        abuf, sizeof(abuf)));
 121                 }
 122         } else if (r->rtm_dst_len) {
 123                 fprintf(fp, "to 0/%d ", r->rtm_dst_len);
 124         }
 125
 126         if (r->rtm_tos) {
 127                 SPRINT_BUF(b1);
 128                 fprintf(fp, "tos %s ", rtnl_dsfield_n2a(r->rtm_tos, b1, sizeof(b1)));
 129         }
 130
 131         if (tb[FRA_FWMARK] || tb[FRA_FWMASK]) {
 132                 __u32 mark = 0, mask = 0;
 133
 134                 if (tb[FRA_FWMARK])
 135                         mark = rta_getattr_u32(tb[FRA_FWMARK]);
 136
 137                 if (tb[FRA_FWMASK] &&
 138                     (mask = rta_getattr_u32(tb[FRA_FWMASK])) != 0xFFFFFFFF)
 139                         fprintf(fp, "fwmark 0x%x/0x%x ", mark, mask);
 140                 else
 141                         fprintf(fp, "fwmark 0x%x ", mark);
 142         }
 143
 144         if (tb[FRA_IFNAME]) {
 145                 fprintf(fp, "iif %s ", rta_getattr_str(tb[FRA_IFNAME]));
 146                 if (r->rtm_flags & FIB_RULE_IIF_DETACHED)
 147                         fprintf(fp, "[detached] ");
 148         }
 149
 150         if (tb[FRA_OIFNAME]) {
 151                 fprintf(fp, "oif %s ", rta_getattr_str(tb[FRA_OIFNAME]));
 152                 if (r->rtm_flags & FIB_RULE_OIF_DETACHED)
 153                         fprintf(fp, "[detached] ");
 154         }
 155
 156         table = rtm_get_table(r, tb);
 157         if (table) {
 158                 fprintf(fp, "lookup %s ", rtnl_rttable_n2a(table, b1, sizeof(b1)));
 159
 160                 if (tb[FRA_SUPPRESS_PREFIXLEN]) {
 161                         int pl = rta_getattr_u32(tb[FRA_SUPPRESS_PREFIXLEN]);
 162                         if (pl != -1) {
 163                                 fprintf(fp, "suppress_prefixlength %d ", pl);
 164                         }
 165                 }
 166                 if (tb[FRA_SUPPRESS_IFGROUP]) {
 167                         int group = rta_getattr_u32(tb[FRA_SUPPRESS_IFGROUP]);
 168                         if (group != -1) {
 169                                 SPRINT_BUF(b1);
 170                                 fprintf(fp, "suppress_ifgroup %s ", rtnl_group_n2a(group, b1, sizeof(b1)));
 171                         }
 172                 }
 173         }
 174
 175         if (tb[FRA_FLOW]) {
 176                 __u32 to = rta_getattr_u32(tb[FRA_FLOW]);
 177                 __u32 from = to>>16;
 178                 to &= 0xFFFF;
 179                 if (from) {
 180                         fprintf(fp, "realms %s/",
 181                                 rtnl_rtrealm_n2a(from, b1, sizeof(b1)));
 182                 }
 183                 fprintf(fp, "%s ",
 184                         rtnl_rtrealm_n2a(to, b1, sizeof(b1)));
 185         }
 186
 187         if (r->rtm_type == RTN_NAT) {
 188                 if (tb[RTA_GATEWAY]) {
 189                         fprintf(fp, "map-to %s ",
 190                                 format_host(r->rtm_family,
 191                                             RTA_PAYLOAD(tb[RTA_GATEWAY]),
 192                                             RTA_DATA(tb[RTA_GATEWAY]),
 193                                             abuf, sizeof(abuf)));
 194                 } else
 195                         fprintf(fp, "masquerade");
 196         } else if (r->rtm_type == FR_ACT_GOTO) {
 197                 fprintf(fp, "goto ");
 198                 if (tb[FRA_GOTO])
 199                         fprintf(fp, "%u", rta_getattr_u32(tb[FRA_GOTO]));
 200                 else
 201                         fprintf(fp, "none");
 202                 if (r->rtm_flags & FIB_RULE_UNRESOLVED)
 203                         fprintf(fp, " [unresolved]");
 204         } else if (r->rtm_type == FR_ACT_NOP)
 205                 fprintf(fp, "nop");
 206         else if (r->rtm_type != RTN_UNICAST)
 207                 fprintf(fp, "%s", rtnl_rtntype_n2a(r->rtm_type, b1, sizeof(b1)));
 208
 209         fprintf(fp, "\n");
 210         fflush(fp);
 211         return 0;
 212 }
 213
 214 static int iprule_list(int argc, char **argv)
 215 {
 216         int af = preferred_family;
 217
 218         if (af == AF_UNSPEC)
 219                 af = AF_INET;
 220
 221         if (argc > 0) {
 222                 fprintf(stderr, "\"ip rule show\" does not take any arguments.\n");
 223                 return -1;
 224         }
 225
 226         if (rtnl_wilddump_request(&rth, af, RTM_GETRULE) < 0) {
 227                 perror("Cannot send dump request");
 228                 return 1;
 229         }
 230
 231         if (rtnl_dump_filter(&rth, print_rule, stdout) < 0) {
 232                 fprintf(stderr, "Dump terminated\n");
 233                 return 1;
 234         }
 235
 236         return 0;
 237 }
 238
 239
 240 static int iprule_modify(int cmd, int argc, char **argv)
 241 {
 242         int table_ok = 0;
 243         struct {
 244                 struct nlmsghdr n;
 245                 struct rtmsg            r;
 246                 char                    buf[1024];
 247         } req;
 248
 249         memset(&req, 0, sizeof(req));
 250
 251         req.n.nlmsg_type = cmd;
 252         req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
 253         req.n.nlmsg_flags = NLM_F_REQUEST;
 254         req.r.rtm_family = preferred_family;
 255         req.r.rtm_protocol = RTPROT_BOOT;
 256         req.r.rtm_scope = RT_SCOPE_UNIVERSE;
 257         req.r.rtm_table = 0;
 258         req.r.rtm_type = RTN_UNSPEC;
 259         req.r.rtm_flags = 0;
 260
 261         if (cmd == RTM_NEWRULE) {
 262                 req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;
 263                 req.r.rtm_type = RTN_UNICAST;
 264         }
 265
 266         while (argc > 0) {
 267                 if (strcmp(*argv, "not") == 0) {
 268                         req.r.rtm_flags |= FIB_RULE_INVERT;
 269                 } else if (strcmp(*argv, "from") == 0) {
 270                         inet_prefix dst;
 271                         NEXT_ARG();
 272                         get_prefix(&dst, *argv, req.r.rtm_family);
 273                         req.r.rtm_src_len = dst.bitlen;
 274                         addattr_l(&req.n, sizeof(req), FRA_SRC, &dst.data, dst.bytelen);
 275                 } else if (strcmp(*argv, "to") == 0) {
 276                         inet_prefix dst;
 277                         NEXT_ARG();
 278                         get_prefix(&dst, *argv, req.r.rtm_family);
 279                         req.r.rtm_dst_len = dst.bitlen;
 280                         addattr_l(&req.n, sizeof(req), FRA_DST, &dst.data, dst.bytelen);
 281                 } else if (matches(*argv, "preference") == 0 ||
 282                            matches(*argv, "order") == 0 ||
 283                            matches(*argv, "priority") == 0) {
 284                         __u32 pref;
 285                         NEXT_ARG();
 286                         if (get_u32(&pref, *argv, 0))
 287                                 invarg("preference value is invalid\n", *argv);
 288                         addattr32(&req.n, sizeof(req), FRA_PRIORITY, pref);
 289                 } else if (strcmp(*argv, "tos") == 0 ||
 290                            matches(*argv, "dsfield") == 0) {
 291                         __u32 tos;
 292                         NEXT_ARG();
 293                         if (rtnl_dsfield_a2n(&tos, *argv))
 294                                 invarg("TOS value is invalid\n", *argv);
 295                         req.r.rtm_tos = tos;
 296                 } else if (strcmp(*argv, "fwmark") == 0) {
 297                         char *slash;
 298                         __u32 fwmark, fwmask;
 299                         NEXT_ARG();
 300                         if ((slash = strchr(*argv, '/')) != NULL)
 301                                 *slash = '\0';
 302                         if (get_u32(&fwmark, *argv, 0))
 303                                 invarg("fwmark value is invalid\n", *argv);
 304                         addattr32(&req.n, sizeof(req), FRA_FWMARK, fwmark);
 305                         if (slash) {
 306                                 if (get_u32(&fwmask, slash+1, 0))
 307                                         invarg("fwmask value is invalid\n", slash+1);
 308                                 addattr32(&req.n, sizeof(req), FRA_FWMASK, fwmask);
 309                         }
 310                 } else if (matches(*argv, "realms") == 0) {
 311                         __u32 realm;
 312                         NEXT_ARG();
 313                         if (get_rt_realms(&realm, *argv))
 314                                 invarg("invalid realms\n", *argv);
 315                         addattr32(&req.n, sizeof(req), FRA_FLOW, realm);
 316                 } else if (matches(*argv, "table") == 0 ||
 317                            strcmp(*argv, "lookup") == 0) {
 318                         __u32 tid;
 319                         NEXT_ARG();
 320                         if (rtnl_rttable_a2n(&tid, *argv))
 321                                 invarg("invalid table ID\n", *argv);
 322                         if (tid < 256)
 323                                 req.r.rtm_table = tid;
 324                         else {
 325                                 req.r.rtm_table = RT_TABLE_UNSPEC;
 326                                 addattr32(&req.n, sizeof(req), FRA_TABLE, tid);
 327                         }
 328                         table_ok = 1;
 329                 } else if (matches(*argv, "suppress_prefixlength") == 0 ||
 330                            strcmp(*argv, "sup_pl") == 0) {
 331                         int pl;
 332                         NEXT_ARG();
 333                         if (get_s32(&pl, *argv, 0) || pl < 0)
 334                                 invarg("suppress_prefixlength value is invalid\n", *argv);
 335                         addattr32(&req.n, sizeof(req), FRA_SUPPRESS_PREFIXLEN, pl);
 336                 } else if (matches(*argv, "suppress_ifgroup") == 0 ||
 337                            strcmp(*argv, "sup_group") == 0) {
 338                         NEXT_ARG();
 339                         int group;
 340                         if (rtnl_group_a2n(&group, *argv))
 341                                 invarg("Invalid \"suppress_ifgroup\" value\n", *argv);
 342                         addattr32(&req.n, sizeof(req), FRA_SUPPRESS_IFGROUP, group);
 343                 } else if (strcmp(*argv, "dev") == 0 ||
 344                            strcmp(*argv, "iif") == 0) {
 345                         NEXT_ARG();
 346                         addattr_l(&req.n, sizeof(req), FRA_IFNAME, *argv, strlen(*argv)+1);
 347                 } else if (strcmp(*argv, "oif") == 0) {
 348                         NEXT_ARG();
 349                         addattr_l(&req.n, sizeof(req), FRA_OIFNAME, *argv, strlen(*argv)+1);
 350                 } else if (strcmp(*argv, "nat") == 0 ||
 351                            matches(*argv, "map-to") == 0) {
 352                         NEXT_ARG();
 353                         fprintf(stderr, "Warning: route NAT is deprecated\n");
 354                         addattr32(&req.n, sizeof(req), RTA_GATEWAY, get_addr32(*argv));
 355                         req.r.rtm_type = RTN_NAT;
 356                 } else {
 357                         int type;
 358
 359                         if (strcmp(*argv, "type") == 0) {
 360                                 NEXT_ARG();
 361                         }
 362                         if (matches(*argv, "help") == 0)
 363                                 usage();
 364                         else if (matches(*argv, "goto") == 0) {
 365                                 __u32 target;
 366                                 type = FR_ACT_GOTO;
 367                                 NEXT_ARG();
 368                                 if (get_u32(&target, *argv, 0))
 369                                         invarg("invalid target\n", *argv);
 370                                 addattr32(&req.n, sizeof(req), FRA_GOTO, target);
 371                         } else if (matches(*argv, "nop") == 0)
 372                                 type = FR_ACT_NOP;
 373                         else if (rtnl_rtntype_a2n(&type, *argv))
 374                                 invarg("Failed to parse rule type", *argv);
 375                         req.r.rtm_type = type;
 376                         table_ok = 1;
 377                 }
 378                 argc--;
 379                 argv++;
 380         }
 381
 382         if (req.r.rtm_family == AF_UNSPEC)
 383                 req.r.rtm_family = AF_INET;
 384
 385         if (!table_ok && cmd == RTM_NEWRULE)
 386                 req.r.rtm_table = RT_TABLE_MAIN;
 387
 388         if (rtnl_talk(&rth, &req.n, 0, 0, NULL) < 0)
 389                 return 2;
 390
 391         return 0;
 392 }
 393
 394
 395 static int flush_rule(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
 396 {
 397         struct rtnl_handle rth2;
 398         struct rtmsg *r = NLMSG_DATA(n);
 399         int len = n->nlmsg_len;
 400         struct rtattr * tb[FRA_MAX+1];
 401
 402         len -= NLMSG_LENGTH(sizeof(*r));
 403         if (len < 0)
 404                 return -1;
 405
 406         parse_rtattr(tb, FRA_MAX, RTM_RTA(r), len);
 407
 408         if (tb[FRA_PRIORITY]) {
 409                 n->nlmsg_type = RTM_DELRULE;
 410                 n->nlmsg_flags = NLM_F_REQUEST;
 411
 412                 if (rtnl_open(&rth2, 0) < 0)
 413                         return -1;
 414
 415                 if (rtnl_talk(&rth2, n, 0, 0, NULL) < 0)
 416                         return -2;
 417
 418                 rtnl_close(&rth2);
 419         }
 420
 421         return 0;
 422 }
 423
 424 static int iprule_flush(int argc, char **argv)
 425 {
 426         int af = preferred_family;
 427
 428         if (af == AF_UNSPEC)
 429                 af = AF_INET;
 430
 431         if (argc > 0) {
 432                 fprintf(stderr, "\"ip rule flush\" does not allow arguments\n");
 433                 return -1;
 434         }
 435
 436         if (rtnl_wilddump_request(&rth, af, RTM_GETRULE) < 0) {
 437                 perror("Cannot send dump request");
 438                 return 1;
 439         }
 440
 441         if (rtnl_dump_filter(&rth, flush_rule, NULL) < 0) {
 442                 fprintf(stderr, "Flush terminated\n");
 443                 return 1;
 444         }
 445
 446         return 0;
 447 }
 448
 449 int do_iprule(int argc, char **argv)
 450 {
 451         if (argc < 1) {
 452                 return iprule_list(0, NULL);
 453         } else if (matches(argv[0], "list") == 0 ||
 454                    matches(argv[0], "lst") == 0 ||
 455                    matches(argv[0], "show") == 0) {
 456                 return iprule_list(argc-1, argv+1);
 457         } else if (matches(argv[0], "add") == 0) {
 458                 return iprule_modify(RTM_NEWRULE, argc-1, argv+1);
 459         } else if (matches(argv[0], "delete") == 0) {
 460                 return iprule_modify(RTM_DELRULE, argc-1, argv+1);
 461         } else if (matches(argv[0], "flush") == 0) {
 462                 return iprule_flush(argc-1, argv+1);
 463         } else if (matches(argv[0], "help") == 0)
 464                 usage();
 465
 466         fprintf(stderr, "Command \"%s\" is unknown, try \"ip rule help\".\n", *argv);
 467         exit(-1);
 468 }
 469
 470 int do_multirule(int argc, char **argv)
 471 {
 472         switch (preferred_family) {
 473         case AF_UNSPEC:
 474         case AF_INET:
 475                 preferred_family = RTNL_FAMILY_IPMR;
 476                 break;
 477         case AF_INET6:
 478                 preferred_family = RTNL_FAMILY_IP6MR;
 479                 break;
 480         case RTNL_FAMILY_IPMR:
 481         case RTNL_FAMILY_IP6MR:
 482                 break;
 483         default:
 484                 fprintf(stderr, "Multicast rules are only supported for IPv4/IPv6, was: %i\n",
 485                         preferred_family);
 486                 exit(-1);
 487         }
 488
 489         return do_iprule(argc, argv);
 490 }