networking/libiproute/iprule.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * This program is free software; you can redistribute it and/or
   4  * modify it under the terms of the GNU General Public License
   5  * as published by the Free Software Foundation; either version
   6  * 2 of the License, or (at your option) any later version.
   7  *
   8  * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
   9  *
  10  * Changes:
  11  *
  12  * Rani Assaf <rani@magic.metawire.com> 980929: resolve addresses
  13  * initially integrated into busybox by Bernhard Reutner-Fischer
  14  */
  15
  16 #include <netinet/in.h>
  17 #include <netinet/ip.h>
  18 #include <arpa/inet.h>
  19
  20 #include "ip_common.h"  /* #include "libbb.h" is inside */
  21 #include "rt_names.h"
  22 #include "utils.h"
  23
  24 /*
  25 static void usage(void) __attribute__((noreturn));
  26
  27 static void usage(void)
  28 {
  29         fprintf(stderr, "Usage: ip rule [ list | add | del ] SELECTOR ACTION\n");
  30         fprintf(stderr, "SELECTOR := [ from PREFIX ] [ to PREFIX ] [ tos TOS ] [ fwmark FWMARK ]\n");
  31         fprintf(stderr, "            [ dev STRING ] [ pref NUMBER ]\n");
  32         fprintf(stderr, "ACTION := [ table TABLE_ID ] [ nat ADDRESS ]\n");
  33         fprintf(stderr, "          [ prohibit | reject | unreachable ]\n");
  34         fprintf(stderr, "          [ realms [SRCREALM/]DSTREALM ]\n");
  35         fprintf(stderr, "TABLE_ID := [ local | main | default | NUMBER ]\n");
  36         exit(-1);
  37 }
  38 */
  39
  40 static int FAST_FUNC print_rule(const struct sockaddr_nl *who UNUSED_PARAM,
  41                                         struct nlmsghdr *n, void *arg UNUSED_PARAM)
  42 {
  43         struct rtmsg *r = NLMSG_DATA(n);
  44         int len = n->nlmsg_len;
  45         int host_len = -1;
  46         struct rtattr * tb[RTA_MAX+1];
  47
  48         if (n->nlmsg_type != RTM_NEWRULE)
  49                 return 0;
  50
  51         len -= NLMSG_LENGTH(sizeof(*r));
  52         if (len < 0)
  53                 return -1;
  54
  55         memset(tb, 0, sizeof(tb));
  56         parse_rtattr(tb, RTA_MAX, RTM_RTA(r), len);
  57
  58         if (r->rtm_family == AF_INET)
  59                 host_len = 32;
  60         else if (r->rtm_family == AF_INET6)
  61                 host_len = 128;
  62 /*      else if (r->rtm_family == AF_DECnet)
  63                 host_len = 16;
  64         else if (r->rtm_family == AF_IPX)
  65                 host_len = 80;
  66 */
  67         printf("%u:\t", tb[RTA_PRIORITY] ?
  68                                         *(unsigned*)RTA_DATA(tb[RTA_PRIORITY])
  69                                         : 0);
  70         printf("from ");
  71         if (tb[RTA_SRC]) {
  72                 if (r->rtm_src_len != host_len) {
  73                         printf("%s/%u",
  74                                 rt_addr_n2a(r->rtm_family, RTA_DATA(tb[RTA_SRC])),
  75                                 r->rtm_src_len
  76                         );
  77                 } else {
  78                         fputs(format_host(r->rtm_family,
  79                                                 RTA_PAYLOAD(tb[RTA_SRC]),
  80                                                 RTA_DATA(tb[RTA_SRC])),
  81                                 stdout
  82                         );
  83                 }
  84         } else if (r->rtm_src_len) {
  85                 printf("0/%d", r->rtm_src_len);
  86         } else {
  87                 printf("all");
  88         }
  89         bb_putchar(' ');
  90
  91         if (tb[RTA_DST]) {
  92                 if (r->rtm_dst_len != host_len) {
  93                         printf("to %s/%u ", rt_addr_n2a(r->rtm_family,
  94                                                          RTA_DATA(tb[RTA_DST])),
  95                                 r->rtm_dst_len
  96                                 );
  97                 } else {
  98                         printf("to %s ", format_host(r->rtm_family,
  99                                                        RTA_PAYLOAD(tb[RTA_DST]),
 100                                                        RTA_DATA(tb[RTA_DST])));
 101                 }
 102         } else if (r->rtm_dst_len) {
 103                 printf("to 0/%d ", r->rtm_dst_len);
 104         }
 105
 106         if (r->rtm_tos) {
 107                 printf("tos %s ", rtnl_dsfield_n2a(r->rtm_tos));
 108         }
 109         if (tb[RTA_PROTOINFO]) {
 110                 printf("fwmark %#x ", *(uint32_t*)RTA_DATA(tb[RTA_PROTOINFO]));
 111         }
 112
 113         if (tb[RTA_IIF]) {
 114                 printf("iif %s ", (char*)RTA_DATA(tb[RTA_IIF]));
 115         }
 116
 117         if (r->rtm_table)
 118                 printf("lookup %s ", rtnl_rttable_n2a(r->rtm_table));
 119
 120         if (tb[RTA_FLOW]) {
 121                 uint32_t to = *(uint32_t*)RTA_DATA(tb[RTA_FLOW]);
 122                 uint32_t from = to>>16;
 123                 to &= 0xFFFF;
 124                 if (from) {
 125                         printf("realms %s/",
 126                                 rtnl_rtrealm_n2a(from));
 127                 }
 128                 printf("%s ",
 129                         rtnl_rtrealm_n2a(to));
 130         }
 131
 132         if (r->rtm_type == RTN_NAT) {
 133                 if (tb[RTA_GATEWAY]) {
 134                         printf("map-to %s ",
 135                                 format_host(r->rtm_family,
 136                                             RTA_PAYLOAD(tb[RTA_GATEWAY]),
 137                                             RTA_DATA(tb[RTA_GATEWAY]))
 138                         );
 139                 } else
 140                         printf("masquerade");
 141         } else if (r->rtm_type != RTN_UNICAST)
 142                 fputs(rtnl_rtntype_n2a(r->rtm_type), stdout);
 143
 144         bb_putchar('\n');
 145         /*fflush_all();*/
 146         return 0;
 147 }
 148
 149 /* Return value becomes exitcode. It's okay to not return at all */
 150 static int iprule_list(char **argv)
 151 {
 152         struct rtnl_handle rth;
 153         int af = preferred_family;
 154
 155         if (af == AF_UNSPEC)
 156                 af = AF_INET;
 157
 158         if (*argv) {
 159                 //bb_error_msg("\"rule show\" needs no arguments");
 160                 bb_warn_ignoring_args(*argv);
 161                 return -1;
 162         }
 163
 164         xrtnl_open(&rth);
 165
 166         xrtnl_wilddump_request(&rth, af, RTM_GETRULE);
 167         xrtnl_dump_filter(&rth, print_rule, NULL);
 168
 169         return 0;
 170 }
 171
 172 /* Return value becomes exitcode. It's okay to not return at all */
 173 static int iprule_modify(int cmd, char **argv)
 174 {
 175         static const char keywords[] ALIGN1 =
 176                 "from\0""to\0""preference\0""order\0""priority\0"
 177                 "tos\0""fwmark\0""realms\0""table\0""lookup\0""dev\0"
 178                 "iif\0""nat\0""map-to\0""type\0""help\0";
 179         enum {
 180                 ARG_from = 1, ARG_to, ARG_preference, ARG_order, ARG_priority,
 181                 ARG_tos, ARG_fwmark, ARG_realms, ARG_table, ARG_lookup, ARG_dev,
 182                 ARG_iif, ARG_nat, ARG_map_to, ARG_type, ARG_help
 183         };
 184         bool table_ok = 0;
 185         struct rtnl_handle rth;
 186         struct {
 187                 struct nlmsghdr n;
 188                 struct rtmsg    r;
 189                 char            buf[1024];
 190         } req;
 191         smalluint key;
 192
 193         memset(&req, 0, sizeof(req));
 194
 195         req.n.nlmsg_type = cmd;
 196         req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
 197         req.n.nlmsg_flags = NLM_F_REQUEST;
 198         req.r.rtm_family = preferred_family;
 199         req.r.rtm_protocol = RTPROT_BOOT;
 200         if (RT_SCOPE_UNIVERSE != 0)
 201                 req.r.rtm_scope = RT_SCOPE_UNIVERSE;
 202         /*req.r.rtm_table = 0; - already is */
 203         if (RTN_UNSPEC != 0)
 204                 req.r.rtm_type = RTN_UNSPEC;
 205
 206         if (cmd == RTM_NEWRULE) {
 207                 req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;
 208                 req.r.rtm_type = RTN_UNICAST;
 209         }
 210
 211         while (*argv) {
 212                 key = index_in_substrings(keywords, *argv) + 1;
 213                 if (key == 0) /* no match found in keywords array, bail out. */
 214                         invarg_1_to_2(*argv, applet_name);
 215                 if (key == ARG_from) {
 216                         inet_prefix dst;
 217                         NEXT_ARG();
 218                         get_prefix(&dst, *argv, req.r.rtm_family);
 219                         req.r.rtm_src_len = dst.bitlen;
 220                         addattr_l(&req.n, sizeof(req), RTA_SRC, &dst.data, dst.bytelen);
 221                 } else if (key == ARG_to) {
 222                         inet_prefix dst;
 223                         NEXT_ARG();
 224                         get_prefix(&dst, *argv, req.r.rtm_family);
 225                         req.r.rtm_dst_len = dst.bitlen;
 226                         addattr_l(&req.n, sizeof(req), RTA_DST, &dst.data, dst.bytelen);
 227                 } else if (key == ARG_preference ||
 228                            key == ARG_order ||
 229                            key == ARG_priority
 230                 ) {
 231                         uint32_t pref;
 232                         NEXT_ARG();
 233                         pref = get_u32(*argv, "preference");
 234                         addattr32(&req.n, sizeof(req), RTA_PRIORITY, pref);
 235                 } else if (key == ARG_tos) {
 236                         uint32_t tos;
 237                         NEXT_ARG();
 238                         if (rtnl_dsfield_a2n(&tos, *argv))
 239                                 invarg_1_to_2(*argv, "TOS");
 240                         req.r.rtm_tos = tos;
 241                 } else if (key == ARG_fwmark) {
 242                         uint32_t fwmark;
 243                         NEXT_ARG();
 244                         fwmark = get_u32(*argv, "fwmark");
 245                         addattr32(&req.n, sizeof(req), RTA_PROTOINFO, fwmark);
 246                 } else if (key == ARG_realms) {
 247                         uint32_t realm;
 248                         NEXT_ARG();
 249                         if (get_rt_realms(&realm, *argv))
 250                                 invarg_1_to_2(*argv, "realms");
 251                         addattr32(&req.n, sizeof(req), RTA_FLOW, realm);
 252                 } else if (key == ARG_table ||
 253                            key == ARG_lookup
 254                 ) {
 255                         uint32_t tid;
 256                         NEXT_ARG();
 257                         if (rtnl_rttable_a2n(&tid, *argv))
 258                                 invarg_1_to_2(*argv, "table ID");
 259                         req.r.rtm_table = tid;
 260                         table_ok = 1;
 261                 } else if (key == ARG_dev ||
 262                            key == ARG_iif
 263                 ) {
 264                         NEXT_ARG();
 265                         addattr_l(&req.n, sizeof(req), RTA_IIF, *argv, strlen(*argv)+1);
 266                 } else if (key == ARG_nat ||
 267                            key == ARG_map_to
 268                 ) {
 269                         NEXT_ARG();
 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 (key == ARG_type) {
 276                                 NEXT_ARG();
 277                         }
 278                         if (key == ARG_help)
 279                                 bb_show_usage();
 280                         if (rtnl_rtntype_a2n(&type, *argv))
 281                                 invarg_1_to_2(*argv, "type");
 282                         req.r.rtm_type = type;
 283                 }
 284                 argv++;
 285         }
 286
 287         if (req.r.rtm_family == AF_UNSPEC)
 288                 req.r.rtm_family = AF_INET;
 289
 290         if (!table_ok && cmd == RTM_NEWRULE)
 291                 req.r.rtm_table = RT_TABLE_MAIN;
 292
 293         xrtnl_open(&rth);
 294
 295         if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
 296                 return 2;
 297
 298         return 0;
 299 }
 300
 301 /* Return value becomes exitcode. It's okay to not return at all */
 302 int FAST_FUNC do_iprule(char **argv)
 303 {
 304         static const char ip_rule_commands[] ALIGN1 =
 305                 "add\0""delete\0""list\0""show\0";
 306         if (*argv) {
 307                 int cmd = index_in_substrings(ip_rule_commands, *argv);
 308                 if (cmd < 0)
 309                         invarg_1_to_2(*argv, applet_name);
 310                 argv++;
 311                 if (cmd < 2)
 312                         return iprule_modify((cmd == 0) ? RTM_NEWRULE : RTM_DELRULE, argv);
 313         }
 314         return iprule_list(argv);
 315 }