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