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 Reutner-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 FAST_FUNC 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         printf("%u:\t", tb[RTA_PRIORITY] ?
  73                                         *(unsigned*)RTA_DATA(tb[RTA_PRIORITY])
  74                                         : 0);
  75         printf("from ");
  76         if (tb[RTA_SRC]) {
  77                 if (r->rtm_src_len != host_len) {
  78                         printf("%s/%u", rt_addr_n2a(r->rtm_family,
  79                                                          RTA_DATA(tb[RTA_SRC]),
  80                                                          abuf, sizeof(abuf)),
  81                                 r->rtm_src_len
  82                                 );
  83                 } else {
  84                         fputs(format_host(r->rtm_family,
  85                                                        RTA_PAYLOAD(tb[RTA_SRC]),
  86                                                        RTA_DATA(tb[RTA_SRC]),
  87                                                        abuf, sizeof(abuf)), stdout);
  88                 }
  89         } else if (r->rtm_src_len) {
  90                 printf("0/%d", r->rtm_src_len);
  91         } else {
  92                 printf("all");
  93         }
  94         bb_putchar(' ');
  95
  96         if (tb[RTA_DST]) {
  97                 if (r->rtm_dst_len != host_len) {
  98                         printf("to %s/%u ", rt_addr_n2a(r->rtm_family,
  99                                                          RTA_DATA(tb[RTA_DST]),
 100                                                          abuf, sizeof(abuf)),
 101                                 r->rtm_dst_len
 102                                 );
 103                 } else {
 104                         printf("to %s ", format_host(r->rtm_family,
 105                                                        RTA_PAYLOAD(tb[RTA_DST]),
 106                                                        RTA_DATA(tb[RTA_DST]),
 107                                                        abuf, sizeof(abuf)));
 108                 }
 109         } else if (r->rtm_dst_len) {
 110                 printf("to 0/%d ", r->rtm_dst_len);
 111         }
 112
 113         if (r->rtm_tos) {
 114                 printf("tos %s ", rtnl_dsfield_n2a(r->rtm_tos, b1));
 115         }
 116         if (tb[RTA_PROTOINFO]) {
 117                 printf("fwmark %#x ", *(uint32_t*)RTA_DATA(tb[RTA_PROTOINFO]));
 118         }
 119
 120         if (tb[RTA_IIF]) {
 121                 printf("iif %s ", (char*)RTA_DATA(tb[RTA_IIF]));
 122         }
 123
 124         if (r->rtm_table)
 125                 printf("lookup %s ", rtnl_rttable_n2a(r->rtm_table, b1));
 126
 127         if (tb[RTA_FLOW]) {
 128                 uint32_t to = *(uint32_t*)RTA_DATA(tb[RTA_FLOW]);
 129                 uint32_t from = to>>16;
 130                 to &= 0xFFFF;
 131                 if (from) {
 132                         printf("realms %s/",
 133                                 rtnl_rtrealm_n2a(from, b1));
 134                 }
 135                 printf("%s ",
 136                         rtnl_rtrealm_n2a(to, b1));
 137         }
 138
 139         if (r->rtm_type == RTN_NAT) {
 140                 if (tb[RTA_GATEWAY]) {
 141                         printf("map-to %s ",
 142                                 format_host(r->rtm_family,
 143                                             RTA_PAYLOAD(tb[RTA_GATEWAY]),
 144                                             RTA_DATA(tb[RTA_GATEWAY]),
 145                                             abuf, sizeof(abuf)));
 146                 } else
 147                         printf("masquerade");
 148         } else if (r->rtm_type != RTN_UNICAST)
 149                 fputs(rtnl_rtntype_n2a(r->rtm_type, b1), stdout);
 150
 151         bb_putchar('\n');
 152         /*fflush_all();*/
 153         return 0;
 154 }
 155
 156 /* Return value becomes exitcode. It's okay to not return at all */
 157 static int iprule_list(char **argv)
 158 {
 159         struct rtnl_handle rth;
 160         int af = preferred_family;
 161
 162         if (af == AF_UNSPEC)
 163                 af = AF_INET;
 164
 165         if (*argv) {
 166                 //bb_error_msg("\"rule show\" needs no arguments");
 167                 bb_warn_ignoring_args(*argv);
 168                 return -1;
 169         }
 170
 171         xrtnl_open(&rth);
 172
 173         xrtnl_wilddump_request(&rth, af, RTM_GETRULE);
 174         xrtnl_dump_filter(&rth, print_rule, NULL);
 175
 176         return 0;
 177 }
 178
 179 /* Return value becomes exitcode. It's okay to not return at all */
 180 static int iprule_modify(int cmd, char **argv)
 181 {
 182         static const char keywords[] ALIGN1 =
 183                 "from\0""to\0""preference\0""order\0""priority\0"
 184                 "tos\0""fwmark\0""realms\0""table\0""lookup\0""dev\0"
 185                 "iif\0""nat\0""map-to\0""type\0""help\0";
 186         enum {
 187                 ARG_from = 1, ARG_to, ARG_preference, ARG_order, ARG_priority,
 188                 ARG_tos, ARG_fwmark, ARG_realms, ARG_table, ARG_lookup, ARG_dev,
 189                 ARG_iif, ARG_nat, ARG_map_to, ARG_type, ARG_help
 190         };
 191         bool table_ok = 0;
 192         struct rtnl_handle rth;
 193         struct {
 194                 struct nlmsghdr n;
 195                 struct rtmsg    r;
 196                 char            buf[1024];
 197         } req;
 198         smalluint key;
 199
 200         memset(&req, 0, sizeof(req));
 201
 202         req.n.nlmsg_type = cmd;
 203         req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
 204         req.n.nlmsg_flags = NLM_F_REQUEST;
 205         req.r.rtm_family = preferred_family;
 206         req.r.rtm_protocol = RTPROT_BOOT;
 207         req.r.rtm_scope = RT_SCOPE_UNIVERSE;
 208         req.r.rtm_table = 0;
 209         req.r.rtm_type = RTN_UNSPEC;
 210
 211         if (cmd == RTM_NEWRULE) {
 212                 req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;
 213                 req.r.rtm_type = RTN_UNICAST;
 214         }
 215
 216         while (*argv) {
 217                 key = index_in_substrings(keywords, *argv) + 1;
 218                 if (key == 0) /* no match found in keywords array, bail out. */
 219                         bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name);
 220                 if (key == ARG_from) {
 221                         inet_prefix dst;
 222                         NEXT_ARG();
 223                         get_prefix(&dst, *argv, req.r.rtm_family);
 224                         req.r.rtm_src_len = dst.bitlen;
 225                         addattr_l(&req.n, sizeof(req), RTA_SRC, &dst.data, dst.bytelen);
 226                 } else if (key == ARG_to) {
 227                         inet_prefix dst;
 228                         NEXT_ARG();
 229                         get_prefix(&dst, *argv, req.r.rtm_family);
 230                         req.r.rtm_dst_len = dst.bitlen;
 231                         addattr_l(&req.n, sizeof(req), RTA_DST, &dst.data, dst.bytelen);
 232                 } else if (key == ARG_preference ||
 233                            key == ARG_order ||
 234                            key == ARG_priority
 235                 ) {
 236                         uint32_t pref;
 237                         NEXT_ARG();
 238                         pref = get_u32(*argv, "preference");
 239                         addattr32(&req.n, sizeof(req), RTA_PRIORITY, pref);
 240                 } else if (key == ARG_tos) {
 241                         uint32_t tos;
 242                         NEXT_ARG();
 243                         if (rtnl_dsfield_a2n(&tos, *argv))
 244                                 invarg(*argv, "TOS");
 245                         req.r.rtm_tos = tos;
 246                 } else if (key == ARG_fwmark) {
 247                         uint32_t fwmark;
 248                         NEXT_ARG();
 249                         fwmark = get_u32(*argv, "fwmark");
 250                         addattr32(&req.n, sizeof(req), RTA_PROTOINFO, fwmark);
 251                 } else if (key == ARG_realms) {
 252                         uint32_t realm;
 253                         NEXT_ARG();
 254                         if (get_rt_realms(&realm, *argv))
 255                                 invarg(*argv, "realms");
 256                         addattr32(&req.n, sizeof(req), RTA_FLOW, realm);
 257                 } else if (key == ARG_table ||
 258                            key == ARG_lookup
 259                 ) {
 260                         uint32_t tid;
 261                         NEXT_ARG();
 262                         if (rtnl_rttable_a2n(&tid, *argv))
 263                                 invarg(*argv, "table ID");
 264                         req.r.rtm_table = tid;
 265                         table_ok = 1;
 266                 } else if (key == ARG_dev ||
 267                            key == ARG_iif
 268                 ) {
 269                         NEXT_ARG();
 270                         addattr_l(&req.n, sizeof(req), RTA_IIF, *argv, strlen(*argv)+1);
 271                 } else if (key == ARG_nat ||
 272                            key == ARG_map_to
 273                 ) {
 274                         NEXT_ARG();
 275                         addattr32(&req.n, sizeof(req), RTA_GATEWAY, get_addr32(*argv));
 276                         req.r.rtm_type = RTN_NAT;
 277                 } else {
 278                         int type;
 279
 280                         if (key == ARG_type) {
 281                                 NEXT_ARG();
 282                         }
 283                         if (key == ARG_help)
 284                                 bb_show_usage();
 285                         if (rtnl_rtntype_a2n(&type, *argv))
 286                                 invarg(*argv, "type");
 287                         req.r.rtm_type = type;
 288                 }
 289                 argv++;
 290         }
 291
 292         if (req.r.rtm_family == AF_UNSPEC)
 293                 req.r.rtm_family = AF_INET;
 294
 295         if (!table_ok && cmd == RTM_NEWRULE)
 296                 req.r.rtm_table = RT_TABLE_MAIN;
 297
 298         xrtnl_open(&rth);
 299
 300         if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
 301                 return 2;
 302
 303         return 0;
 304 }
 305
 306 /* Return value becomes exitcode. It's okay to not return at all */
 307 int do_iprule(char **argv)
 308 {
 309         static const char ip_rule_commands[] ALIGN1 =
 310                 "add\0""delete\0""list\0""show\0";
 311         if (*argv) {
 312                 smalluint cmd = index_in_substrings(ip_rule_commands, *argv);
 313                 if (cmd > 3)
 314                         bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name);
 315                 argv++;
 316                 if (cmd < 2)
 317                         return iprule_modify((cmd == 0) ? RTM_NEWRULE : RTM_DELRULE, argv);
 318         }
 319         return iprule_list(argv);
 320 }