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