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