networking/libiproute/iprule.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * iprule.c             "ip rule".
   4  *
   5  *              This program is free software; you can redistribute it and/or
   6  *              modify it under the terms of the GNU General Public License
   7  *              as published by the Free Software Foundation; either version
   8  *              2 of the License, or (at your option) any later version.
   9  *
  10  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  11  *
  12  *
  13  * Changes:
  14  *
  15  * Rani Assaf <rani@magic.metawire.com> 980929: resolve addresses
  16  * initially integrated into busybox by Bernhard Fischer
  17  */
  18
  19 #include <netinet/in.h>
  20 #include <netinet/ip.h>
  21 #include <arpa/inet.h>
  22
  23 #include "ip_common.h"  /* #include "libbb.h" is inside */
  24 #include "rt_names.h"
  25 #include "utils.h"
  26
  27 /*
  28 static void usage(void) __attribute__((noreturn));
  29
  30 static void usage(void)
  31 {
  32         fprintf(stderr, "Usage: ip rule [ list | add | del ] SELECTOR ACTION\n");
  33         fprintf(stderr, "SELECTOR := [ from PREFIX ] [ to PREFIX ] [ tos TOS ] [ fwmark FWMARK ]\n");
  34         fprintf(stderr, "            [ dev STRING ] [ pref NUMBER ]\n");
  35         fprintf(stderr, "ACTION := [ table TABLE_ID ] [ nat ADDRESS ]\n");
  36         fprintf(stderr, "          [ prohibit | reject | unreachable ]\n");
  37         fprintf(stderr, "          [ realms [SRCREALM/]DSTREALM ]\n");
  38         fprintf(stderr, "TABLE_ID := [ local | main | default | NUMBER ]\n");
  39         exit(-1);
  40 }
  41 */
  42
  43 static int print_rule(const struct sockaddr_nl *who UNUSED_PARAM,
  44                                         struct nlmsghdr *n, void *arg UNUSED_PARAM)
  45 {
  46         struct rtmsg *r = NLMSG_DATA(n);
  47         int len = n->nlmsg_len;
  48         int host_len = -1;
  49         struct rtattr * tb[RTA_MAX+1];
  50         char abuf[256];
  51         SPRINT_BUF(b1);
  52
  53         if (n->nlmsg_type != RTM_NEWRULE)
  54                 return 0;
  55
  56         len -= NLMSG_LENGTH(sizeof(*r));
  57         if (len < 0)
  58                 return -1;
  59
  60         memset(tb, 0, sizeof(tb));
  61         parse_rtattr(tb, RTA_MAX, RTM_RTA(r), len);
  62
  63         if (r->rtm_family == AF_INET)
  64                 host_len = 32;
  65         else if (r->rtm_family == AF_INET6)
  66                 host_len = 128;
  67 /*      else if (r->rtm_family == AF_DECnet)
  68                 host_len = 16;
  69         else if (r->rtm_family == AF_IPX)
  70                 host_len = 80;
  71 */
  72         if (tb[RTA_PRIORITY])
  73                 printf("%u:\t", *(unsigned*)RTA_DATA(tb[RTA_PRIORITY]));
  74         else
  75                 printf("0:\t");
  76
  77         printf("from ");
  78         if (tb[RTA_SRC]) {
  79                 if (r->rtm_src_len != host_len) {
  80                         printf("%s/%u", rt_addr_n2a(r->rtm_family,
  81                                                          RTA_PAYLOAD(tb[RTA_SRC]),
  82                                                          RTA_DATA(tb[RTA_SRC]),
  83                                                          abuf, sizeof(abuf)),
  84                                 r->rtm_src_len
  85                                 );
  86                 } else {
  87                         fputs(format_host(r->rtm_family,
  88                                                        RTA_PAYLOAD(tb[RTA_SRC]),
  89                                                        RTA_DATA(tb[RTA_SRC]),
  90                                                        abuf, sizeof(abuf)), stdout);
  91                 }
  92         } else if (r->rtm_src_len) {
  93                 printf("0/%d", r->rtm_src_len);
  94         } else {
  95                 printf("all");
  96         }
  97         bb_putchar(' ');
  98
  99         if (tb[RTA_DST]) {
 100                 if (r->rtm_dst_len != host_len) {
 101                         printf("to %s/%u ", rt_addr_n2a(r->rtm_family,
 102                                                          RTA_PAYLOAD(tb[RTA_DST]),
 103                                                          RTA_DATA(tb[RTA_DST]),
 104                                                          abuf, sizeof(abuf)),
 105                                 r->rtm_dst_len
 106                                 );
 107                 } else {
 108                         printf("to %s ", format_host(r->rtm_family,
 109                                                        RTA_PAYLOAD(tb[RTA_DST]),
 110                                                        RTA_DATA(tb[RTA_DST]),
 111                                                        abuf, sizeof(abuf)));
 112                 }
 113         } else if (r->rtm_dst_len) {
 114                 printf("to 0/%d ", r->rtm_dst_len);
 115         }
 116
 117         if (r->rtm_tos) {
 118                 printf("tos %s ", rtnl_dsfield_n2a(r->rtm_tos, b1, sizeof(b1)));
 119         }
 120         if (tb[RTA_PROTOINFO]) {
 121                 printf("fwmark %#x ", *(uint32_t*)RTA_DATA(tb[RTA_PROTOINFO]));
 122         }
 123
 124         if (tb[RTA_IIF]) {
 125                 printf("iif %s ", (char*)RTA_DATA(tb[RTA_IIF]));
 126         }
 127
 128         if (r->rtm_table)
 129                 printf("lookup %s ", rtnl_rttable_n2a(r->rtm_table, b1, sizeof(b1)));
 130
 131         if (tb[RTA_FLOW]) {
 132                 uint32_t to = *(uint32_t*)RTA_DATA(tb[RTA_FLOW]);
 133                 uint32_t from = to>>16;
 134                 to &= 0xFFFF;
 135                 if (from) {
 136                         printf("realms %s/",
 137                                 rtnl_rtrealm_n2a(from, b1, sizeof(b1)));
 138                 }
 139                 printf("%s ",
 140                         rtnl_rtrealm_n2a(to, b1, sizeof(b1)));
 141         }
 142
 143         if (r->rtm_type == RTN_NAT) {
 144                 if (tb[RTA_GATEWAY]) {
 145                         printf("map-to %s ",
 146                                 format_host(r->rtm_family,
 147                                             RTA_PAYLOAD(tb[RTA_GATEWAY]),
 148                                             RTA_DATA(tb[RTA_GATEWAY]),
 149                                             abuf, sizeof(abuf)));
 150                 } else
 151                         printf("masquerade");
 152         } else if (r->rtm_type != RTN_UNICAST)
 153                 fputs(rtnl_rtntype_n2a(r->rtm_type, b1, sizeof(b1)), stdout);
 154
 155         bb_putchar('\n');
 156         /*fflush(stdout);*/
 157         return 0;
 158 }
 159
 160 /* Return value becomes exitcode. It's okay to not return at all */
 161 static int iprule_list(char **argv)
 162 {
 163         struct rtnl_handle rth;
 164         int af = preferred_family;
 165
 166         if (af == AF_UNSPEC)
 167                 af = AF_INET;
 168
 169         if (*argv) {
 170                 //bb_error_msg("\"rule show\" needs no arguments");
 171                 bb_warn_ignoring_args(1);
 172                 return -1;
 173         }
 174
 175         xrtnl_open(&rth);
 176
 177         xrtnl_wilddump_request(&rth, af, RTM_GETRULE);
 178         xrtnl_dump_filter(&rth, print_rule, NULL);
 179
 180         return 0;
 181 }
 182
 183 /* Return value becomes exitcode. It's okay to not return at all */
 184 static int iprule_modify(int cmd, char **argv)
 185 {
 186         static const char keywords[] ALIGN1 =
 187                 "from\0""to\0""preference\0""order\0""priority\0"
 188                 "tos\0""fwmark\0""realms\0""table\0""lookup\0""dev\0"
 189                 "iif\0""nat\0""map-to\0""type\0""help\0";
 190         enum {
 191                 ARG_from = 1, ARG_to, ARG_preference, ARG_order, ARG_priority,
 192                 ARG_tos, ARG_fwmark, ARG_realms, ARG_table, ARG_lookup, ARG_dev,
 193                 ARG_iif, ARG_nat, ARG_map_to, ARG_type, ARG_help
 194         };
 195         bool table_ok = 0;
 196         struct rtnl_handle rth;
 197         struct {
 198                 struct nlmsghdr n;
 199                 struct rtmsg    r;
 200                 char            buf[1024];
 201         } req;
 202         smalluint key;
 203
 204         memset(&req, 0, sizeof(req));
 205
 206         req.n.nlmsg_type = cmd;
 207         req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
 208         req.n.nlmsg_flags = NLM_F_REQUEST;
 209         req.r.rtm_family = preferred_family;
 210         req.r.rtm_protocol = RTPROT_BOOT;
 211         req.r.rtm_scope = RT_SCOPE_UNIVERSE;
 212         req.r.rtm_table = 0;
 213         req.r.rtm_type = RTN_UNSPEC;
 214
 215         if (cmd == RTM_NEWRULE) {
 216                 req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;
 217                 req.r.rtm_type = RTN_UNICAST;
 218         }
 219
 220         while (*argv) {
 221                 key = index_in_substrings(keywords, *argv) + 1;
 222                 if (key == 0) /* no match found in keywords array, bail out. */
 223                         bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name);
 224                 if (key == ARG_from) {
 225                         inet_prefix dst;
 226                         NEXT_ARG();
 227                         get_prefix(&dst, *argv, req.r.rtm_family);
 228                         req.r.rtm_src_len = dst.bitlen;
 229                         addattr_l(&req.n, sizeof(req), RTA_SRC, &dst.data, dst.bytelen);
 230                 } else if (key == ARG_to) {
 231                         inet_prefix dst;
 232                         NEXT_ARG();
 233                         get_prefix(&dst, *argv, req.r.rtm_family);
 234                         req.r.rtm_dst_len = dst.bitlen;
 235                         addattr_l(&req.n, sizeof(req), RTA_DST, &dst.data, dst.bytelen);
 236                 } else if (key == ARG_preference ||
 237                            key == ARG_order ||
 238                            key == ARG_priority) {
 239                         uint32_t pref;
 240                         NEXT_ARG();
 241                         if (get_u32(&pref, *argv, 0))
 242                                 invarg(*argv, "preference");
 243                         addattr32(&req.n, sizeof(req), RTA_PRIORITY, pref);
 244                 } else if (key == ARG_tos) {
 245                         uint32_t tos;
 246                         NEXT_ARG();
 247                         if (rtnl_dsfield_a2n(&tos, *argv))
 248                                 invarg(*argv, "TOS");
 249                         req.r.rtm_tos = tos;
 250                 } else if (key == ARG_fwmark) {
 251                         uint32_t fwmark;
 252                         NEXT_ARG();
 253                         if (get_u32(&fwmark, *argv, 0))
 254                                 invarg(*argv, "fwmark");
 255                         addattr32(&req.n, sizeof(req), RTA_PROTOINFO, fwmark);
 256                 } else if (key == ARG_realms) {
 257                         uint32_t realm;
 258                         NEXT_ARG();
 259                         if (get_rt_realms(&realm, *argv))
 260                                 invarg(*argv, "realms");
 261                         addattr32(&req.n, sizeof(req), RTA_FLOW, realm);
 262                 } else if (key == ARG_table ||
 263                            key == ARG_lookup) {
 264                         uint32_t tid;
 265                         NEXT_ARG();
 266                         if (rtnl_rttable_a2n(&tid, *argv))
 267                                 invarg(*argv, "table ID");
 268                         req.r.rtm_table = tid;
 269                         table_ok = 1;
 270                 } else if (key == ARG_dev ||
 271                            key == ARG_iif) {
 272                         NEXT_ARG();
 273                         addattr_l(&req.n, sizeof(req), RTA_IIF, *argv, strlen(*argv)+1);
 274                 } else if (key == ARG_nat ||
 275                            key == ARG_map_to) {
 276                         NEXT_ARG();
 277                         addattr32(&req.n, sizeof(req), RTA_GATEWAY, get_addr32(*argv));
 278                         req.r.rtm_type = RTN_NAT;
 279                 } else {
 280                         int type;
 281
 282                         if (key == ARG_type) {
 283                                 NEXT_ARG();
 284                         }
 285                         if (key == ARG_help)
 286                                 bb_show_usage();
 287                         if (rtnl_rtntype_a2n(&type, *argv))
 288                                 invarg(*argv, "type");
 289                         req.r.rtm_type = type;
 290                 }
 291                 argv++;
 292         }
 293
 294         if (req.r.rtm_family == AF_UNSPEC)
 295                 req.r.rtm_family = AF_INET;
 296
 297         if (!table_ok && cmd == RTM_NEWRULE)
 298                 req.r.rtm_table = RT_TABLE_MAIN;
 299
 300         xrtnl_open(&rth);
 301
 302         if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
 303                 return 2;
 304
 305         return 0;
 306 }
 307
 308 /* Return value becomes exitcode. It's okay to not return at all */
 309 int do_iprule(char **argv)
 310 {
 311         static const char ip_rule_commands[] ALIGN1 =
 312                 "add\0""delete\0""list\0""show\0";
 313         int cmd = 2; /* list */
 314
 315         if (!*argv)
 316                 return iprule_list(argv);
 317
 318         cmd = index_in_substrings(ip_rule_commands, *argv);
 319         switch (cmd) {
 320                 case 0: /* add */
 321                         cmd = RTM_NEWRULE;
 322                         break;
 323                 case 1: /* delete */
 324                         cmd = RTM_DELRULE;
 325                         break;
 326                 case 2: /* list */
 327                 case 3: /* show */
 328                         return iprule_list(argv+1);
 329                         break;
 330                 default:
 331                         bb_error_msg_and_die("unknown command %s", *argv);
 332         }
 333         return iprule_modify(cmd, argv+1);
 334 }