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  * Changes:
  13  *
  14  * Rani Assaf <rani@magic.metawire.com> 980929: resolve addresses
  15  */
  16
  17 #include <stdio.h>
  18 #include <stdlib.h>
  19 #include <unistd.h>
  20 #include <syslog.h>
  21 #include <fcntl.h>
  22 #include <sys/socket.h>
  23 #include <netinet/in.h>
  24 #include <netinet/ip.h>
  25 #include <arpa/inet.h>
  26 #include <string.h>
  27 #include <linux/fib_rules.h>
  28
  29 #include "rt_names.h"
  30 #include "utils.h"
  31 #include "ip_common.h"
  32
  33 extern struct rtnl_handle rth;
  34
  35 static void usage(void) __attribute__((noreturn));
  36
  37 static void usage(void)
  38 {
  39         fprintf(stderr, "Usage: ip rule [ list | add | del | flush ] SELECTOR ACTION\n");
  40         fprintf(stderr, "SELECTOR := [ not ] [ from PREFIX ] [ to PREFIX ] [ tos TOS ] [ fwmark FWMARK[/MASK] ]\n");
  41         fprintf(stderr, "            [ dev STRING ] [ pref NUMBER ]\n");
  42         fprintf(stderr, "ACTION := [ table TABLE_ID ]\n");
  43         fprintf(stderr, "          [ prohibit | reject | unreachable ]\n");
  44         fprintf(stderr, "          [ realms [SRCREALM/]DSTREALM ]\n");
  45         fprintf(stderr, "          [ goto NUMBER ]\n");
  46         fprintf(stderr, "TABLE_ID := [ local | main | default | NUMBER ]\n");
  47         exit(-1);
  48 }
  49
  50 int print_rule(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
  51 {
  52         FILE *fp = (FILE*)arg;
  53         struct rtmsg *r = NLMSG_DATA(n);
  54         int len = n->nlmsg_len;
  55         int host_len = -1;
  56         __u32 table;
  57         struct rtattr * tb[FRA_MAX+1];
  58         char abuf[256];
  59         SPRINT_BUF(b1);
  60
  61         if (n->nlmsg_type != RTM_NEWRULE && n->nlmsg_type != RTM_DELRULE)
  62                 return 0;
  63
  64         len -= NLMSG_LENGTH(sizeof(*r));
  65         if (len < 0)
  66                 return -1;
  67
  68         parse_rtattr(tb, FRA_MAX, RTM_RTA(r), len);
  69
  70         if (r->rtm_family == AF_INET)
  71                 host_len = 32;
  72         else if (r->rtm_family == AF_INET6)
  73                 host_len = 128;
  74         else if (r->rtm_family == AF_DECnet)
  75                 host_len = 16;
  76         else if (r->rtm_family == AF_IPX)
  77                 host_len = 80;
  78
  79         if (n->nlmsg_type == RTM_DELRULE)
  80                 fprintf(fp, "Deleted ");
  81
  82         if (tb[FRA_PRIORITY])
  83                 fprintf(fp, "%u:\t", *(unsigned*)RTA_DATA(tb[FRA_PRIORITY]));
  84         else
  85                 fprintf(fp, "0:\t");
  86
  87         if (r->rtm_flags & FIB_RULE_INVERT)
  88                 fprintf(fp, "not ");
  89
  90         if (tb[FRA_SRC]) {
  91                 if (r->rtm_src_len != host_len) {
  92                         fprintf(fp, "from %s/%u ", rt_addr_n2a(r->rtm_family,
  93                                                          RTA_PAYLOAD(tb[FRA_SRC]),
  94                                                          RTA_DATA(tb[FRA_SRC]),
  95                                                          abuf, sizeof(abuf)),
  96                                 r->rtm_src_len
  97                                 );
  98                 } else {
  99                         fprintf(fp, "from %s ", format_host(r->rtm_family,
 100                                                        RTA_PAYLOAD(tb[FRA_SRC]),
 101                                                        RTA_DATA(tb[FRA_SRC]),
 102                                                        abuf, sizeof(abuf))
 103                                 );
 104                 }
 105         } else if (r->rtm_src_len) {
 106                 fprintf(fp, "from 0/%d ", r->rtm_src_len);
 107         } else {
 108                 fprintf(fp, "from all ");
 109         }
 110
 111         if (tb[FRA_DST]) {
 112                 if (r->rtm_dst_len != host_len) {
 113                         fprintf(fp, "to %s/%u ", rt_addr_n2a(r->rtm_family,
 114                                                          RTA_PAYLOAD(tb[FRA_DST]),
 115                                                          RTA_DATA(tb[FRA_DST]),
 116                                                          abuf, sizeof(abuf)),
 117                                 r->rtm_dst_len
 118                                 );
 119                 } else {
 120                         fprintf(fp, "to %s ", format_host(r->rtm_family,
 121                                                        RTA_PAYLOAD(tb[FRA_DST]),
 122                                                        RTA_DATA(tb[FRA_DST]),
 123                                                        abuf, sizeof(abuf)));
 124                 }
 125         } else if (r->rtm_dst_len) {
 126                 fprintf(fp, "to 0/%d ", r->rtm_dst_len);
 127         }
 128
 129         if (r->rtm_tos) {
 130                 SPRINT_BUF(b1);
 131                 fprintf(fp, "tos %s ", rtnl_dsfield_n2a(r->rtm_tos, b1, sizeof(b1)));
 132         }
 133
 134         if (tb[FRA_FWMARK] || tb[FRA_FWMASK]) {
 135                 __u32 mark = 0, mask = 0;
 136
 137                 if (tb[FRA_FWMARK])
 138                         mark = *(__u32*)RTA_DATA(tb[FRA_FWMARK]);
 139
 140                 if (tb[FRA_FWMASK] &&
 141                     (mask = *(__u32*)RTA_DATA(tb[FRA_FWMASK])) != 0xFFFFFFFF)
 142                         fprintf(fp, "fwmark 0x%x/0x%x ", mark, mask);
 143                 else
 144                         fprintf(fp, "fwmark 0x%x ", mark);
 145         }
 146
 147         if (tb[FRA_IFNAME]) {
 148                 fprintf(fp, "iif %s ", (char*)RTA_DATA(tb[FRA_IFNAME]));
 149                 if (r->rtm_flags & FIB_RULE_DEV_DETACHED)
 150                         fprintf(fp, "[detached] ");
 151         }
 152
 153         table = rtm_get_table(r, tb);
 154         if (table)
 155                 fprintf(fp, "lookup %s ", rtnl_rttable_n2a(table, b1, sizeof(b1)));
 156
 157         if (tb[FRA_FLOW]) {
 158                 __u32 to = *(__u32*)RTA_DATA(tb[FRA_FLOW]);
 159                 __u32 from = to>>16;
 160                 to &= 0xFFFF;
 161                 if (from) {
 162                         fprintf(fp, "realms %s/",
 163                                 rtnl_rtrealm_n2a(from, b1, sizeof(b1)));
 164                 }
 165                 fprintf(fp, "%s ",
 166                         rtnl_rtrealm_n2a(to, b1, sizeof(b1)));
 167         }
 168
 169         if (r->rtm_type == RTN_NAT) {
 170                 if (tb[RTA_GATEWAY]) {
 171                         fprintf(fp, "map-to %s ",
 172                                 format_host(r->rtm_family,
 173                                             RTA_PAYLOAD(tb[RTA_GATEWAY]),
 174                                             RTA_DATA(tb[RTA_GATEWAY]),
 175                                             abuf, sizeof(abuf)));
 176                 } else
 177                         fprintf(fp, "masquerade");
 178         } else if (r->rtm_type == FR_ACT_GOTO) {
 179                 fprintf(fp, "goto ");
 180                 if (tb[FRA_GOTO])
 181                         fprintf(fp, "%u", *(__u32 *) RTA_DATA(tb[FRA_GOTO]));
 182                 else
 183                         fprintf(fp, "none");
 184                 if (r->rtm_flags & FIB_RULE_UNRESOLVED)
 185                         fprintf(fp, " [unresolved]");
 186         } else if (r->rtm_type == FR_ACT_NOP)
 187                 fprintf(fp, "nop");
 188         else if (r->rtm_type != RTN_UNICAST)
 189                 fprintf(fp, "%s", rtnl_rtntype_n2a(r->rtm_type, b1, sizeof(b1)));
 190
 191         fprintf(fp, "\n");
 192         fflush(fp);
 193         return 0;
 194 }
 195
 196 static int iprule_list(int argc, char **argv)
 197 {
 198         int af = preferred_family;
 199
 200         if (af == AF_UNSPEC)
 201                 af = AF_INET;
 202
 203         if (argc > 0) {
 204                 fprintf(stderr, "\"ip rule show\" does not take any arguments.\n");
 205                 return -1;
 206         }
 207
 208         if (rtnl_wilddump_request(&rth, af, RTM_GETRULE) < 0) {
 209                 perror("Cannot send dump request");
 210                 return 1;
 211         }
 212
 213         if (rtnl_dump_filter(&rth, print_rule, stdout, NULL, NULL) < 0) {
 214                 fprintf(stderr, "Dump terminated\n");
 215                 return 1;
 216         }
 217
 218         return 0;
 219 }
 220
 221
 222 static int iprule_modify(int cmd, int argc, char **argv)
 223 {
 224         int table_ok = 0;
 225         struct {
 226                 struct nlmsghdr         n;
 227                 struct rtmsg            r;
 228                 char                    buf[1024];
 229         } req;
 230
 231         memset(&req, 0, sizeof(req));
 232
 233         req.n.nlmsg_type = cmd;
 234         req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
 235         req.n.nlmsg_flags = NLM_F_REQUEST;
 236         req.r.rtm_family = preferred_family;
 237         req.r.rtm_protocol = RTPROT_BOOT;
 238         req.r.rtm_scope = RT_SCOPE_UNIVERSE;
 239         req.r.rtm_table = 0;
 240         req.r.rtm_type = RTN_UNSPEC;
 241         req.r.rtm_flags = 0;
 242
 243         if (cmd == RTM_NEWRULE) {
 244                 req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;
 245                 req.r.rtm_type = RTN_UNICAST;
 246         }
 247
 248         while (argc > 0) {
 249                 if (strcmp(*argv, "not") == 0) {
 250                         req.r.rtm_flags |= FIB_RULE_INVERT;
 251                 } else if (strcmp(*argv, "from") == 0) {
 252                         inet_prefix dst;
 253                         NEXT_ARG();
 254                         get_prefix(&dst, *argv, req.r.rtm_family);
 255                         req.r.rtm_src_len = dst.bitlen;
 256                         addattr_l(&req.n, sizeof(req), FRA_SRC, &dst.data, dst.bytelen);
 257                 } else if (strcmp(*argv, "to") == 0) {
 258                         inet_prefix dst;
 259                         NEXT_ARG();
 260                         get_prefix(&dst, *argv, req.r.rtm_family);
 261                         req.r.rtm_dst_len = dst.bitlen;
 262                         addattr_l(&req.n, sizeof(req), FRA_DST, &dst.data, dst.bytelen);
 263                 } else if (matches(*argv, "preference") == 0 ||
 264                            matches(*argv, "order") == 0 ||
 265                            matches(*argv, "priority") == 0) {
 266                         __u32 pref;
 267                         NEXT_ARG();
 268                         if (get_u32(&pref, *argv, 0))
 269                                 invarg("preference value is invalid\n", *argv);
 270                         addattr32(&req.n, sizeof(req), FRA_PRIORITY, pref);
 271                 } else if (strcmp(*argv, "tos") == 0) {
 272                         __u32 tos;
 273                         NEXT_ARG();
 274                         if (rtnl_dsfield_a2n(&tos, *argv))
 275                                 invarg("TOS value is invalid\n", *argv);
 276                         req.r.rtm_tos = tos;
 277                 } else if (strcmp(*argv, "fwmark") == 0) {
 278                         char *slash;
 279                         __u32 fwmark, fwmask;
 280                         NEXT_ARG();
 281                         if ((slash = strchr(*argv, '/')) != NULL)
 282                                 *slash = '\0';
 283                         if (get_u32(&fwmark, *argv, 0))
 284                                 invarg("fwmark value is invalid\n", *argv);
 285                         addattr32(&req.n, sizeof(req), FRA_FWMARK, fwmark);
 286                         if (slash) {
 287                                 if (get_u32(&fwmask, slash+1, 0))
 288                                         invarg("fwmask value is invalid\n", slash+1);
 289                                 addattr32(&req.n, sizeof(req), FRA_FWMASK, fwmask);
 290                         }
 291                 } else if (matches(*argv, "realms") == 0) {
 292                         __u32 realm;
 293                         NEXT_ARG();
 294                         if (get_rt_realms(&realm, *argv))
 295                                 invarg("invalid realms\n", *argv);
 296                         addattr32(&req.n, sizeof(req), FRA_FLOW, realm);
 297                 } else if (matches(*argv, "table") == 0 ||
 298                            strcmp(*argv, "lookup") == 0) {
 299                         __u32 tid;
 300                         NEXT_ARG();
 301                         if (rtnl_rttable_a2n(&tid, *argv))
 302                                 invarg("invalid table ID\n", *argv);
 303                         if (tid < 256)
 304                                 req.r.rtm_table = tid;
 305                         else {
 306                                 req.r.rtm_table = RT_TABLE_UNSPEC;
 307                                 addattr32(&req.n, sizeof(req), FRA_TABLE, tid);
 308                         }
 309                         table_ok = 1;
 310                 } else if (strcmp(*argv, "dev") == 0 ||
 311                            strcmp(*argv, "iif") == 0) {
 312                         NEXT_ARG();
 313                         addattr_l(&req.n, sizeof(req), FRA_IFNAME, *argv, strlen(*argv)+1);
 314                 } else if (strcmp(*argv, "nat") == 0 ||
 315                            matches(*argv, "map-to") == 0) {
 316                         NEXT_ARG();
 317                         fprintf(stderr, "Warning: route NAT is deprecated\n");
 318                         addattr32(&req.n, sizeof(req), RTA_GATEWAY, get_addr32(*argv));
 319                         req.r.rtm_type = RTN_NAT;
 320                 } else {
 321                         int type;
 322
 323                         if (strcmp(*argv, "type") == 0) {
 324                                 NEXT_ARG();
 325                         }
 326                         if (matches(*argv, "help") == 0)
 327                                 usage();
 328                         else if (matches(*argv, "goto") == 0) {
 329                                 __u32 target;
 330                                 type = FR_ACT_GOTO;
 331                                 NEXT_ARG();
 332                                 if (get_u32(&target, *argv, 0))
 333                                         invarg("invalid target\n", *argv);
 334                                 addattr32(&req.n, sizeof(req), FRA_GOTO, target);
 335                         } else if (matches(*argv, "nop") == 0)
 336                                 type = FR_ACT_NOP;
 337                         else if (rtnl_rtntype_a2n(&type, *argv))
 338                                 invarg("Failed to parse rule type", *argv);
 339                         req.r.rtm_type = type;
 340                         table_ok = 1;
 341                 }
 342                 argc--;
 343                 argv++;
 344         }
 345
 346         if (req.r.rtm_family == AF_UNSPEC)
 347                 req.r.rtm_family = AF_INET;
 348
 349         if (!table_ok && cmd == RTM_NEWRULE)
 350                 req.r.rtm_table = RT_TABLE_MAIN;
 351
 352         if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
 353                 return 2;
 354
 355         return 0;
 356 }
 357
 358
 359 static int flush_rule(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
 360 {
 361         struct rtnl_handle rth2;
 362         struct rtmsg *r = NLMSG_DATA(n);
 363         int len = n->nlmsg_len;
 364         struct rtattr * tb[FRA_MAX+1];
 365
 366         len -= NLMSG_LENGTH(sizeof(*r));
 367         if (len < 0)
 368                 return -1;
 369
 370         parse_rtattr(tb, FRA_MAX, RTM_RTA(r), len);
 371
 372         if (tb[FRA_PRIORITY]) {
 373                 n->nlmsg_type = RTM_DELRULE;
 374                 n->nlmsg_flags = NLM_F_REQUEST;
 375
 376                 if (rtnl_open(&rth2, 0) < 0)
 377                         return -1;
 378
 379                 if (rtnl_talk(&rth2, n, 0, 0, NULL, NULL, NULL) < 0)
 380                         return -2;
 381
 382                 rtnl_close(&rth2);
 383         }
 384
 385         return 0;
 386 }
 387
 388 static int iprule_flush(int argc, char **argv)
 389 {
 390         int af = preferred_family;
 391
 392         if (af == AF_UNSPEC)
 393                 af = AF_INET;
 394
 395         if (argc > 0) {
 396                 fprintf(stderr, "\"ip rule flush\" does not allow arguments\n");
 397                 return -1;
 398         }
 399
 400         if (rtnl_wilddump_request(&rth, af, RTM_GETRULE) < 0) {
 401                 perror("Cannot send dump request");
 402                 return 1;
 403         }
 404
 405         if (rtnl_dump_filter(&rth, flush_rule, NULL, NULL, NULL) < 0) {
 406                 fprintf(stderr, "Flush terminated\n");
 407                 return 1;
 408         }
 409
 410         return 0;
 411 }
 412
 413 int do_iprule(int argc, char **argv)
 414 {
 415         if (argc < 1) {
 416                 return iprule_list(0, NULL);
 417         } else if (matches(argv[0], "list") == 0 ||
 418                    matches(argv[0], "lst") == 0 ||
 419                    matches(argv[0], "show") == 0) {
 420                 return iprule_list(argc-1, argv+1);
 421         } else if (matches(argv[0], "add") == 0) {
 422                 return iprule_modify(RTM_NEWRULE, argc-1, argv+1);
 423         } else if (matches(argv[0], "delete") == 0) {
 424                 return iprule_modify(RTM_DELRULE, argc-1, argv+1);
 425         } else if (matches(argv[0], "flush") == 0) {
 426                 return iprule_flush(argc-1, argv+1);
 427         } else if (matches(argv[0], "help") == 0)
 428                 usage();
 429
 430         fprintf(stderr, "Command \"%s\" is unknown, try \"ip rule help\".\n", *argv);
 431         exit(-1);
 432 }
 433