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_PAYLOAD(tb[FRA_SRC]),
  93                                                          RTA_DATA(tb[FRA_SRC]),
  94                                                          abuf, sizeof(abuf)),
  95                                 r->rtm_src_len
  96                                 );
  97                 } else {
  98                         fprintf(fp, "from %s ", format_host(r->rtm_family,
  99                                                        RTA_PAYLOAD(tb[FRA_SRC]),
 100                                                        RTA_DATA(tb[FRA_SRC]),
 101                                                        abuf, sizeof(abuf))
 102                                 );
 103                 }
 104         } else if (r->rtm_src_len) {
 105                 fprintf(fp, "from 0/%d ", r->rtm_src_len);
 106         } else {
 107                 fprintf(fp, "from all ");
 108         }
 109
 110         if (tb[FRA_DST]) {
 111                 if (r->rtm_dst_len != host_len) {
 112                         fprintf(fp, "to %s/%u ", rt_addr_n2a(r->rtm_family,
 113                                                          RTA_PAYLOAD(tb[FRA_DST]),
 114                                                          RTA_DATA(tb[FRA_DST]),
 115                                                          abuf, sizeof(abuf)),
 116                                 r->rtm_dst_len
 117                                 );
 118                 } else {
 119                         fprintf(fp, "to %s ", format_host(r->rtm_family,
 120                                                        RTA_PAYLOAD(tb[FRA_DST]),
 121                                                        RTA_DATA(tb[FRA_DST]),
 122                                                        abuf, sizeof(abuf)));
 123                 }
 124         } else if (r->rtm_dst_len) {
 125                 fprintf(fp, "to 0/%d ", r->rtm_dst_len);
 126         }
 127
 128         if (r->rtm_tos) {
 129                 SPRINT_BUF(b1);
 130                 fprintf(fp, "tos %s ", rtnl_dsfield_n2a(r->rtm_tos, b1, sizeof(b1)));
 131         }
 132
 133         if (tb[FRA_FWMARK] || tb[FRA_FWMASK]) {
 134                 __u32 mark = 0, mask = 0;
 135
 136                 if (tb[FRA_FWMARK])
 137                         mark = rta_getattr_u32(tb[FRA_FWMARK]);
 138
 139                 if (tb[FRA_FWMASK] &&
 140                     (mask = rta_getattr_u32(tb[FRA_FWMASK])) != 0xFFFFFFFF)
 141                         fprintf(fp, "fwmark 0x%x/0x%x ", mark, mask);
 142                 else
 143                         fprintf(fp, "fwmark 0x%x ", mark);
 144         }
 145
 146         if (tb[FRA_IFNAME]) {
 147                 fprintf(fp, "iif %s ", rta_getattr_str(tb[FRA_IFNAME]));
 148                 if (r->rtm_flags & FIB_RULE_IIF_DETACHED)
 149                         fprintf(fp, "[detached] ");
 150         }
 151
 152         if (tb[FRA_OIFNAME]) {
 153                 fprintf(fp, "oif %s ", rta_getattr_str(tb[FRA_OIFNAME]));
 154                 if (r->rtm_flags & FIB_RULE_OIF_DETACHED)
 155                         fprintf(fp, "[detached] ");
 156         }
 157
 158         table = rtm_get_table(r, tb);
 159         if (table) {
 160                 fprintf(fp, "lookup %s ", rtnl_rttable_n2a(table, b1, sizeof(b1)));
 161
 162                 if (tb[FRA_SUPPRESS_PREFIXLEN]) {
 163                         int pl = rta_getattr_u32(tb[FRA_SUPPRESS_PREFIXLEN]);
 164                         if (pl != -1) {
 165                                 fprintf(fp, "suppress_prefixlength %d ", pl);
 166                         }
 167                 }
 168                 if (tb[FRA_SUPPRESS_IFGROUP]) {
 169                         int group = rta_getattr_u32(tb[FRA_SUPPRESS_IFGROUP]);
 170                         if (group != -1) {
 171                                 SPRINT_BUF(b1);
 172                                 fprintf(fp, "suppress_ifgroup %s ", rtnl_group_n2a(group, b1, sizeof(b1)));
 173                         }
 174                 }
 175         }
 176
 177         if (tb[FRA_FLOW]) {
 178                 __u32 to = rta_getattr_u32(tb[FRA_FLOW]);
 179                 __u32 from = to>>16;
 180                 to &= 0xFFFF;
 181                 if (from) {
 182                         fprintf(fp, "realms %s/",
 183                                 rtnl_rtrealm_n2a(from, b1, sizeof(b1)));
 184                 }
 185                 fprintf(fp, "%s ",
 186                         rtnl_rtrealm_n2a(to, b1, sizeof(b1)));
 187         }
 188
 189         if (r->rtm_type == RTN_NAT) {
 190                 if (tb[RTA_GATEWAY]) {
 191                         fprintf(fp, "map-to %s ",
 192                                 format_host(r->rtm_family,
 193                                             RTA_PAYLOAD(tb[RTA_GATEWAY]),
 194                                             RTA_DATA(tb[RTA_GATEWAY]),
 195                                             abuf, sizeof(abuf)));
 196                 } else
 197                         fprintf(fp, "masquerade");
 198         } else if (r->rtm_type == FR_ACT_GOTO) {
 199                 fprintf(fp, "goto ");
 200                 if (tb[FRA_GOTO])
 201                         fprintf(fp, "%u", rta_getattr_u32(tb[FRA_GOTO]));
 202                 else
 203                         fprintf(fp, "none");
 204                 if (r->rtm_flags & FIB_RULE_UNRESOLVED)
 205                         fprintf(fp, " [unresolved]");
 206         } else if (r->rtm_type == FR_ACT_NOP)
 207                 fprintf(fp, "nop");
 208         else if (r->rtm_type != RTN_UNICAST)
 209                 fprintf(fp, "%s", rtnl_rtntype_n2a(r->rtm_type, b1, sizeof(b1)));
 210
 211         fprintf(fp, "\n");
 212         fflush(fp);
 213         return 0;
 214 }
 215
 216 static int iprule_list(int argc, char **argv)
 217 {
 218         int af = preferred_family;
 219
 220         if (af == AF_UNSPEC)
 221                 af = AF_INET;
 222
 223         if (argc > 0) {
 224                 fprintf(stderr, "\"ip rule show\" does not take any arguments.\n");
 225                 return -1;
 226         }
 227
 228         if (rtnl_wilddump_request(&rth, af, RTM_GETRULE) < 0) {
 229                 perror("Cannot send dump request");
 230                 return 1;
 231         }
 232
 233         if (rtnl_dump_filter(&rth, print_rule, stdout) < 0) {
 234                 fprintf(stderr, "Dump terminated\n");
 235                 return 1;
 236         }
 237
 238         return 0;
 239 }
 240
 241
 242 static int iprule_modify(int cmd, int argc, char **argv)
 243 {
 244         int table_ok = 0;
 245         struct {
 246                 struct nlmsghdr         n;
 247                 struct rtmsg            r;
 248                 char                    buf[1024];
 249         } req;
 250
 251         memset(&req, 0, sizeof(req));
 252
 253         req.n.nlmsg_type = cmd;
 254         req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
 255         req.n.nlmsg_flags = NLM_F_REQUEST;
 256         req.r.rtm_family = preferred_family;
 257         req.r.rtm_protocol = RTPROT_BOOT;
 258         req.r.rtm_scope = RT_SCOPE_UNIVERSE;
 259         req.r.rtm_table = 0;
 260         req.r.rtm_type = RTN_UNSPEC;
 261         req.r.rtm_flags = 0;
 262
 263         if (cmd == RTM_NEWRULE) {
 264                 req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;
 265                 req.r.rtm_type = RTN_UNICAST;
 266         }
 267
 268         while (argc > 0) {
 269                 if (strcmp(*argv, "not") == 0) {
 270                         req.r.rtm_flags |= FIB_RULE_INVERT;
 271                 } else if (strcmp(*argv, "from") == 0) {
 272                         inet_prefix dst;
 273                         NEXT_ARG();
 274                         get_prefix(&dst, *argv, req.r.rtm_family);
 275                         req.r.rtm_src_len = dst.bitlen;
 276                         addattr_l(&req.n, sizeof(req), FRA_SRC, &dst.data, dst.bytelen);
 277                 } else if (strcmp(*argv, "to") == 0) {
 278                         inet_prefix dst;
 279                         NEXT_ARG();
 280                         get_prefix(&dst, *argv, req.r.rtm_family);
 281                         req.r.rtm_dst_len = dst.bitlen;
 282                         addattr_l(&req.n, sizeof(req), FRA_DST, &dst.data, dst.bytelen);
 283                 } else if (matches(*argv, "preference") == 0 ||
 284                            matches(*argv, "order") == 0 ||
 285                            matches(*argv, "priority") == 0) {
 286                         __u32 pref;
 287                         NEXT_ARG();
 288                         if (get_u32(&pref, *argv, 0))
 289                                 invarg("preference value is invalid\n", *argv);
 290                         addattr32(&req.n, sizeof(req), FRA_PRIORITY, pref);
 291                 } else if (strcmp(*argv, "tos") == 0 ||
 292                            matches(*argv, "dsfield") == 0) {
 293                         __u32 tos;
 294                         NEXT_ARG();
 295                         if (rtnl_dsfield_a2n(&tos, *argv))
 296                                 invarg("TOS value is invalid\n", *argv);
 297                         req.r.rtm_tos = tos;
 298                 } else if (strcmp(*argv, "fwmark") == 0) {
 299                         char *slash;
 300                         __u32 fwmark, fwmask;
 301                         NEXT_ARG();
 302                         if ((slash = strchr(*argv, '/')) != NULL)
 303                                 *slash = '\0';
 304                         if (get_u32(&fwmark, *argv, 0))
 305                                 invarg("fwmark value is invalid\n", *argv);
 306                         addattr32(&req.n, sizeof(req), FRA_FWMARK, fwmark);
 307                         if (slash) {
 308                                 if (get_u32(&fwmask, slash+1, 0))
 309                                         invarg("fwmask value is invalid\n", slash+1);
 310                                 addattr32(&req.n, sizeof(req), FRA_FWMASK, fwmask);
 311                         }
 312                 } else if (matches(*argv, "realms") == 0) {
 313                         __u32 realm;
 314                         NEXT_ARG();
 315                         if (get_rt_realms(&realm, *argv))
 316                                 invarg("invalid realms\n", *argv);
 317                         addattr32(&req.n, sizeof(req), FRA_FLOW, realm);
 318                 } else if (matches(*argv, "table") == 0 ||
 319                            strcmp(*argv, "lookup") == 0) {
 320                         __u32 tid;
 321                         NEXT_ARG();
 322                         if (rtnl_rttable_a2n(&tid, *argv))
 323                                 invarg("invalid table ID\n", *argv);
 324                         if (tid < 256)
 325                                 req.r.rtm_table = tid;
 326                         else {
 327                                 req.r.rtm_table = RT_TABLE_UNSPEC;
 328                                 addattr32(&req.n, sizeof(req), FRA_TABLE, tid);
 329                         }
 330                         table_ok = 1;
 331                 } else if (matches(*argv, "suppress_prefixlength") == 0 ||
 332                            strcmp(*argv, "sup_pl") == 0) {
 333                         int pl;
 334                         NEXT_ARG();
 335                         if (get_s32(&pl, *argv, 0) || pl < 0)
 336                                 invarg("suppress_prefixlength value is invalid\n", *argv);
 337                         addattr32(&req.n, sizeof(req), FRA_SUPPRESS_PREFIXLEN, pl);
 338                 } else if (matches(*argv, "suppress_ifgroup") == 0 ||
 339                            strcmp(*argv, "sup_group") == 0) {
 340                         NEXT_ARG();
 341                         int group;
 342                         if (rtnl_group_a2n(&group, *argv))
 343                                 invarg("Invalid \"suppress_ifgroup\" value\n", *argv);
 344                         addattr32(&req.n, sizeof(req), FRA_SUPPRESS_IFGROUP, group);
 345                 } else if (strcmp(*argv, "dev") == 0 ||
 346                            strcmp(*argv, "iif") == 0) {
 347                         NEXT_ARG();
 348                         addattr_l(&req.n, sizeof(req), FRA_IFNAME, *argv, strlen(*argv)+1);
 349                 } else if (strcmp(*argv, "oif") == 0) {
 350                         NEXT_ARG();
 351                         addattr_l(&req.n, sizeof(req), FRA_OIFNAME, *argv, strlen(*argv)+1);
 352                 } else if (strcmp(*argv, "nat") == 0 ||
 353                            matches(*argv, "map-to") == 0) {
 354                         NEXT_ARG();
 355                         fprintf(stderr, "Warning: route NAT is deprecated\n");
 356                         addattr32(&req.n, sizeof(req), RTA_GATEWAY, get_addr32(*argv));
 357                         req.r.rtm_type = RTN_NAT;
 358                 } else {
 359                         int type;
 360
 361                         if (strcmp(*argv, "type") == 0) {
 362                                 NEXT_ARG();
 363                         }
 364                         if (matches(*argv, "help") == 0)
 365                                 usage();
 366                         else if (matches(*argv, "goto") == 0) {
 367                                 __u32 target;
 368                                 type = FR_ACT_GOTO;
 369                                 NEXT_ARG();
 370                                 if (get_u32(&target, *argv, 0))
 371                                         invarg("invalid target\n", *argv);
 372                                 addattr32(&req.n, sizeof(req), FRA_GOTO, target);
 373                         } else if (matches(*argv, "nop") == 0)
 374                                 type = FR_ACT_NOP;
 375                         else if (rtnl_rtntype_a2n(&type, *argv))
 376                                 invarg("Failed to parse rule type", *argv);
 377                         req.r.rtm_type = type;
 378                         table_ok = 1;
 379                 }
 380                 argc--;
 381                 argv++;
 382         }
 383
 384         if (req.r.rtm_family == AF_UNSPEC)
 385                 req.r.rtm_family = AF_INET;
 386
 387         if (!table_ok && cmd == RTM_NEWRULE)
 388                 req.r.rtm_table = RT_TABLE_MAIN;
 389
 390         if (rtnl_talk(&rth, &req.n, 0, 0, NULL) < 0)
 391                 return 2;
 392
 393         return 0;
 394 }
 395
 396
 397 static int flush_rule(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
 398 {
 399         struct rtnl_handle rth2;
 400         struct rtmsg *r = NLMSG_DATA(n);
 401         int len = n->nlmsg_len;
 402         struct rtattr * tb[FRA_MAX+1];
 403
 404         len -= NLMSG_LENGTH(sizeof(*r));
 405         if (len < 0)
 406                 return -1;
 407
 408         parse_rtattr(tb, FRA_MAX, RTM_RTA(r), len);
 409
 410         if (tb[FRA_PRIORITY]) {
 411                 n->nlmsg_type = RTM_DELRULE;
 412                 n->nlmsg_flags = NLM_F_REQUEST;
 413
 414                 if (rtnl_open(&rth2, 0) < 0)
 415                         return -1;
 416
 417                 if (rtnl_talk(&rth2, n, 0, 0, NULL) < 0)
 418                         return -2;
 419
 420                 rtnl_close(&rth2);
 421         }
 422
 423         return 0;
 424 }
 425
 426 static int iprule_flush(int argc, char **argv)
 427 {
 428         int af = preferred_family;
 429
 430         if (af == AF_UNSPEC)
 431                 af = AF_INET;
 432
 433         if (argc > 0) {
 434                 fprintf(stderr, "\"ip rule flush\" does not allow arguments\n");
 435                 return -1;
 436         }
 437
 438         if (rtnl_wilddump_request(&rth, af, RTM_GETRULE) < 0) {
 439                 perror("Cannot send dump request");
 440                 return 1;
 441         }
 442
 443         if (rtnl_dump_filter(&rth, flush_rule, NULL) < 0) {
 444                 fprintf(stderr, "Flush terminated\n");
 445                 return 1;
 446         }
 447
 448         return 0;
 449 }
 450
 451 int do_iprule(int argc, char **argv)
 452 {
 453         if (argc < 1) {
 454                 return iprule_list(0, NULL);
 455         } else if (matches(argv[0], "list") == 0 ||
 456                    matches(argv[0], "lst") == 0 ||
 457                    matches(argv[0], "show") == 0) {
 458                 return iprule_list(argc-1, argv+1);
 459         } else if (matches(argv[0], "add") == 0) {
 460                 return iprule_modify(RTM_NEWRULE, argc-1, argv+1);
 461         } else if (matches(argv[0], "delete") == 0) {
 462                 return iprule_modify(RTM_DELRULE, argc-1, argv+1);
 463         } else if (matches(argv[0], "flush") == 0) {
 464                 return iprule_flush(argc-1, argv+1);
 465         } else if (matches(argv[0], "help") == 0)
 466                 usage();
 467
 468         fprintf(stderr, "Command \"%s\" is unknown, try \"ip rule help\".\n", *argv);
 469         exit(-1);
 470 }
 471
 472 int do_multirule(int argc, char **argv)
 473 {
 474         switch (preferred_family) {
 475         case AF_UNSPEC:
 476         case AF_INET:
 477                 preferred_family = RTNL_FAMILY_IPMR;
 478                 break;
 479         case AF_INET6:
 480                 preferred_family = RTNL_FAMILY_IP6MR;
 481                 break;
 482         case RTNL_FAMILY_IPMR:
 483         case RTNL_FAMILY_IP6MR:
 484                 break;
 485         default:
 486                 fprintf(stderr, "Multicast rules are only supported for IPv4/IPv6, was: %i\n",
 487                         preferred_family);
 488                 exit(-1);
 489         }
 490
 491         return do_iprule(argc, argv);
 492 }