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 (at) 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 } 461
