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, "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[RTA_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, RTA_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[RTA_PRIORITY])
  82                 fprintf(fp, "%u:\t", *(unsigned*)RTA_DATA(tb[RTA_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[RTA_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[RTA_SRC]),
  93                                                          RTA_DATA(tb[RTA_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[RTA_SRC]),
 100                                                        RTA_DATA(tb[RTA_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[RTA_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[RTA_DST]),
 114                                                          RTA_DATA(tb[RTA_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[RTA_DST]),
 121                                                        RTA_DATA(tb[RTA_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         if (tb[RTA_PROTOINFO] || tb[RTA_FWMASK]) {
 133                 __u32 mark = 0, mask = 0;
 134
 135                 if (tb[RTA_PROTOINFO])
 136                         mark = *(__u32*)RTA_DATA(tb[RTA_PROTOINFO]);
 137
 138                 if (tb[RTA_FWMASK] &&
 139                     (mask = *(__u32*)RTA_DATA(tb[RTA_FWMASK])) != 0xFFFFFFFF)
 140                         fprintf(fp, "fwmark 0x%x/0x%x ", mark, mask);
 141                 else
 142                         fprintf(fp, "fwmark 0x%x ", mark);
 143         }
 144
 145         if (tb[RTA_IIF]) {
 146                 fprintf(fp, "iif %s ", (char*)RTA_DATA(tb[RTA_IIF]));
 147         }
 148
 149         table = rtm_get_table(r, tb);
 150         if (table)
 151                 fprintf(fp, "lookup %s ", rtnl_rttable_n2a(table, b1, sizeof(b1)));
 152
 153         if (tb[RTA_FLOW]) {
 154                 __u32 to = *(__u32*)RTA_DATA(tb[RTA_FLOW]);
 155                 __u32 from = to>>16;
 156                 to &= 0xFFFF;
 157                 if (from) {
 158                         fprintf(fp, "realms %s/",
 159                                 rtnl_rtrealm_n2a(from, b1, sizeof(b1)));
 160                 }
 161                 fprintf(fp, "%s ",
 162                         rtnl_rtrealm_n2a(to, b1, sizeof(b1)));
 163         }
 164
 165         if (r->rtm_type == RTN_NAT) {
 166                 if (tb[RTA_GATEWAY]) {
 167                         fprintf(fp, "map-to %s ",
 168                                 format_host(r->rtm_family,
 169                                             RTA_PAYLOAD(tb[RTA_GATEWAY]),
 170                                             RTA_DATA(tb[RTA_GATEWAY]),
 171                                             abuf, sizeof(abuf)));
 172                 } else
 173                         fprintf(fp, "masquerade");
 174         } else if (r->rtm_type != RTN_UNICAST)
 175                 fprintf(fp, "%s", rtnl_rtntype_n2a(r->rtm_type, b1, sizeof(b1)));
 176
 177         fprintf(fp, "\n");
 178         fflush(fp);
 179         return 0;
 180 }
 181
 182 static int iprule_list(int argc, char **argv)
 183 {
 184         int af = preferred_family;
 185
 186         if (af == AF_UNSPEC)
 187                 af = AF_INET;
 188
 189         if (argc > 0) {
 190                 fprintf(stderr, "\"ip rule show\" does not take any arguments.\n");
 191                 return -1;
 192         }
 193
 194         if (rtnl_wilddump_request(&rth, af, RTM_GETRULE) < 0) {
 195                 perror("Cannot send dump request");
 196                 return 1;
 197         }
 198
 199         if (rtnl_dump_filter(&rth, print_rule, stdout, NULL, NULL) < 0) {
 200                 fprintf(stderr, "Dump terminated\n");
 201                 return 1;
 202         }
 203
 204         return 0;
 205 }
 206
 207
 208 static int iprule_modify(int cmd, int argc, char **argv)
 209 {
 210         int table_ok = 0;
 211         struct {
 212                 struct nlmsghdr         n;
 213                 struct rtmsg            r;
 214                 char                    buf[1024];
 215         } req;
 216
 217         memset(&req, 0, sizeof(req));
 218
 219         req.n.nlmsg_type = cmd;
 220         req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
 221         req.n.nlmsg_flags = NLM_F_REQUEST;
 222         req.r.rtm_family = preferred_family;
 223         req.r.rtm_protocol = RTPROT_BOOT;
 224         req.r.rtm_scope = RT_SCOPE_UNIVERSE;
 225         req.r.rtm_table = 0;
 226         req.r.rtm_type = RTN_UNSPEC;
 227         req.r.rtm_flags = 0;
 228
 229         if (cmd == RTM_NEWRULE) {
 230                 req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;
 231                 req.r.rtm_type = RTN_UNICAST;
 232         }
 233
 234         while (argc > 0) {
 235                 if (strcmp(*argv, "not") == 0) {
 236                         req.r.rtm_flags |= FIB_RULE_INVERT;
 237                 } else if (strcmp(*argv, "from") == 0) {
 238                         inet_prefix dst;
 239                         NEXT_ARG();
 240                         get_prefix(&dst, *argv, req.r.rtm_family);
 241                         req.r.rtm_src_len = dst.bitlen;
 242                         addattr_l(&req.n, sizeof(req), RTA_SRC, &dst.data, dst.bytelen);
 243                 } else if (strcmp(*argv, "to") == 0) {
 244                         inet_prefix dst;
 245                         NEXT_ARG();
 246                         get_prefix(&dst, *argv, req.r.rtm_family);
 247                         req.r.rtm_dst_len = dst.bitlen;
 248                         addattr_l(&req.n, sizeof(req), RTA_DST, &dst.data, dst.bytelen);
 249                 } else if (matches(*argv, "preference") == 0 ||
 250                            matches(*argv, "order") == 0 ||
 251                            matches(*argv, "priority") == 0) {
 252                         __u32 pref;
 253                         NEXT_ARG();
 254                         if (get_u32(&pref, *argv, 0))
 255                                 invarg("preference value is invalid\n", *argv);
 256                         addattr32(&req.n, sizeof(req), RTA_PRIORITY, pref);
 257                 } else if (strcmp(*argv, "tos") == 0) {
 258                         __u32 tos;
 259                         NEXT_ARG();
 260                         if (rtnl_dsfield_a2n(&tos, *argv))
 261                                 invarg("TOS value is invalid\n", *argv);
 262                         req.r.rtm_tos = tos;
 263                 } else if (strcmp(*argv, "fwmark") == 0) {
 264                         char *slash;
 265                         __u32 fwmark, fwmask;
 266                         NEXT_ARG();
 267                         if ((slash = strchr(*argv, '/')) != NULL)
 268                                 *slash = '\0';
 269                         if (get_u32(&fwmark, *argv, 0))
 270                                 invarg("fwmark value is invalid\n", *argv);
 271                         addattr32(&req.n, sizeof(req), RTA_PROTOINFO, fwmark);
 272                         if (slash) {
 273                                 if (get_u32(&fwmask, slash+1, 0))
 274                                         invarg("fwmask value is invalid\n", slash+1);
 275                                 addattr32(&req.n, sizeof(req), RTA_FWMASK, fwmask);
 276                         }
 277                 } else if (matches(*argv, "realms") == 0) {
 278                         __u32 realm;
 279                         NEXT_ARG();
 280                         if (get_rt_realms(&realm, *argv))
 281                                 invarg("invalid realms\n", *argv);
 282                         addattr32(&req.n, sizeof(req), RTA_FLOW, realm);
 283                 } else if (matches(*argv, "table") == 0 ||
 284                            strcmp(*argv, "lookup") == 0) {
 285                         __u32 tid;
 286                         NEXT_ARG();
 287                         if (rtnl_rttable_a2n(&tid, *argv))
 288                                 invarg("invalid table ID\n", *argv);
 289                         if (tid < 256)
 290                                 req.r.rtm_table = tid;
 291                         else {
 292                                 req.r.rtm_table = RT_TABLE_UNSPEC;
 293                                 addattr32(&req.n, sizeof(req), RTA_TABLE, tid);
 294                         }
 295                         table_ok = 1;
 296                 } else if (strcmp(*argv, "dev") == 0 ||
 297                            strcmp(*argv, "iif") == 0) {
 298                         NEXT_ARG();
 299                         addattr_l(&req.n, sizeof(req), RTA_IIF, *argv, strlen(*argv)+1);
 300                 } else if (strcmp(*argv, "nat") == 0 ||
 301                            matches(*argv, "map-to") == 0) {
 302                         NEXT_ARG();
 303                         fprintf(stderr, "Warning: route NAT is deprecated\n");
 304                         addattr32(&req.n, sizeof(req), RTA_GATEWAY, get_addr32(*argv));
 305                         req.r.rtm_type = RTN_NAT;
 306                 } else {
 307                         int type;
 308
 309                         if (strcmp(*argv, "type") == 0) {
 310                                 NEXT_ARG();
 311                         }
 312                         if (matches(*argv, "help") == 0)
 313                                 usage();
 314                         if (rtnl_rtntype_a2n(&type, *argv))
 315                                 invarg("Failed to parse rule type", *argv);
 316                         req.r.rtm_type = type;
 317                 }
 318                 argc--;
 319                 argv++;
 320         }
 321
 322         if (req.r.rtm_family == AF_UNSPEC)
 323                 req.r.rtm_family = AF_INET;
 324
 325         if (!table_ok && cmd == RTM_NEWRULE)
 326                 req.r.rtm_table = RT_TABLE_MAIN;
 327
 328         if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
 329                 return 2;
 330
 331         return 0;
 332 }
 333
 334
 335 static int flush_rule(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
 336 {
 337         struct rtnl_handle rth2;
 338         struct rtmsg *r = NLMSG_DATA(n);
 339         int len = n->nlmsg_len;
 340         struct rtattr * tb[RTA_MAX+1];
 341
 342         len -= NLMSG_LENGTH(sizeof(*r));
 343         if (len < 0)
 344                 return -1;
 345
 346         parse_rtattr(tb, RTA_MAX, RTM_RTA(r), len);
 347
 348         if (tb[RTA_PRIORITY]) {
 349                 n->nlmsg_type = RTM_DELRULE;
 350                 n->nlmsg_flags = NLM_F_REQUEST;
 351
 352                 if (rtnl_open(&rth2, 0) < 0)
 353                         return -1;
 354
 355                 if (rtnl_talk(&rth2, n, 0, 0, NULL, NULL, NULL) < 0)
 356                         return -2;
 357
 358                 rtnl_close(&rth2);
 359         }
 360
 361         return 0;
 362 }
 363
 364 static int iprule_flush(int argc, char **argv)
 365 {
 366         int af = preferred_family;
 367
 368         if (af == AF_UNSPEC)
 369                 af = AF_INET;
 370
 371         if (argc > 0) {
 372                 fprintf(stderr, "\"ip rule flush\" does not allow arguments\n");
 373                 return -1;
 374         }
 375
 376         if (rtnl_wilddump_request(&rth, af, RTM_GETRULE) < 0) {
 377                 perror("Cannot send dump request");
 378                 return 1;
 379         }
 380
 381         if (rtnl_dump_filter(&rth, flush_rule, NULL, NULL, NULL) < 0) {
 382                 fprintf(stderr, "Flush terminated\n");
 383                 return 1;
 384         }
 385
 386         return 0;
 387 }
 388
 389 int do_iprule(int argc, char **argv)
 390 {
 391         if (argc < 1) {
 392                 return iprule_list(0, NULL);
 393         } else if (matches(argv[0], "list") == 0 ||
 394                    matches(argv[0], "lst") == 0 ||
 395                    matches(argv[0], "show") == 0) {
 396                 return iprule_list(argc-1, argv+1);
 397         } else if (matches(argv[0], "add") == 0) {
 398                 return iprule_modify(RTM_NEWRULE, argc-1, argv+1);
 399         } else if (matches(argv[0], "delete") == 0) {
 400                 return iprule_modify(RTM_DELRULE, argc-1, argv+1);
 401         } else if (matches(argv[0], "flush") == 0) {
 402                 return iprule_flush(argc-1, argv+1);
 403         } else if (matches(argv[0], "help") == 0)
 404                 usage();
 405
 406         fprintf(stderr, "Command \"%s\" is unknown, try \"ip rule help\".\n", *argv);
 407         exit(-1);
 408 }
 409