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 <syslog.h>
  20 //#include <sys/socket.h>
  21 #include <netinet/in.h>
  22 #include <netinet/ip.h>
  23 #include <arpa/inet.h>
  24
  25 #include "ip_common.h"  /* #include "libbb.h" is inside */
  26 #include "rt_names.h"
  27 #include "utils.h"
  28
  29 /*
  30 static void usage(void) __attribute__((noreturn));
  31
  32 static void usage(void)
  33 {
  34         fprintf(stderr, "Usage: ip rule [ list | add | del ] SELECTOR ACTION\n");
  35         fprintf(stderr, "SELECTOR := [ from PREFIX ] [ to PREFIX ] [ tos TOS ] [ fwmark FWMARK ]\n");
  36         fprintf(stderr, "            [ dev STRING ] [ pref NUMBER ]\n");
  37         fprintf(stderr, "ACTION := [ table TABLE_ID ] [ nat ADDRESS ]\n");
  38         fprintf(stderr, "          [ prohibit | reject | unreachable ]\n");
  39         fprintf(stderr, "          [ realms [SRCREALM/]DSTREALM ]\n");
  40         fprintf(stderr, "TABLE_ID := [ local | main | default | NUMBER ]\n");
  41         exit(-1);
  42 }
  43 */
  44
  45 static int print_rule(struct sockaddr_nl *who ATTRIBUTE_UNUSED,
  46                                         struct nlmsghdr *n, void *arg)
  47 {
  48         FILE *fp = (FILE*)arg;
  49         struct rtmsg *r = NLMSG_DATA(n);
  50         int len = n->nlmsg_len;
  51         int host_len = -1;
  52         struct rtattr * tb[RTA_MAX+1];
  53         char abuf[256];
  54         SPRINT_BUF(b1);
  55
  56         if (n->nlmsg_type != RTM_NEWRULE)
  57                 return 0;
  58
  59         len -= NLMSG_LENGTH(sizeof(*r));
  60         if (len < 0)
  61                 return -1;
  62
  63         memset(tb, 0, sizeof(tb));
  64         parse_rtattr(tb, RTA_MAX, RTM_RTA(r), len);
  65
  66         if (r->rtm_family == AF_INET)
  67                 host_len = 32;
  68         else if (r->rtm_family == AF_INET6)
  69                 host_len = 128;
  70 /*      else if (r->rtm_family == AF_DECnet)
  71                 host_len = 16;
  72         else if (r->rtm_family == AF_IPX)
  73                 host_len = 80;
  74 */
  75         if (tb[RTA_PRIORITY])
  76                 fprintf(fp, "%u:\t", *(unsigned*)RTA_DATA(tb[RTA_PRIORITY]));
  77         else
  78                 fprintf(fp, "0:\t");
  79
  80         fprintf(fp, "from ");
  81         if (tb[RTA_SRC]) {
  82                 if (r->rtm_src_len != host_len) {
  83                         fprintf(fp, "%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                         fputs(format_host(r->rtm_family,
  91                                                        RTA_PAYLOAD(tb[RTA_SRC]),
  92                                                        RTA_DATA(tb[RTA_SRC]),
  93                                                        abuf, sizeof(abuf)), fp);
  94                 }
  95         } else if (r->rtm_src_len) {
  96                 fprintf(fp, "0/%d", r->rtm_src_len);
  97         } else {
  98                 fprintf(fp, "all");
  99         }
 100         fprintf(fp, " ");
 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                 fprintf(fp, "tos %s ", rtnl_dsfield_n2a(r->rtm_tos, b1, sizeof(b1)));
 122         }
 123         if (tb[RTA_PROTOINFO]) {
 124                 fprintf(fp, "fwmark %#x ", *(uint32_t*)RTA_DATA(tb[RTA_PROTOINFO]));
 125         }
 126
 127         if (tb[RTA_IIF]) {
 128                 fprintf(fp, "iif %s ", (char*)RTA_DATA(tb[RTA_IIF]));
 129         }
 130
 131         if (r->rtm_table)
 132                 fprintf(fp, "lookup %s ", rtnl_rttable_n2a(r->rtm_table, b1, sizeof(b1)));
 133
 134         if (tb[RTA_FLOW]) {
 135                 uint32_t to = *(uint32_t*)RTA_DATA(tb[RTA_FLOW]);
 136                 uint32_t from = to>>16;
 137                 to &= 0xFFFF;
 138                 if (from) {
 139                         fprintf(fp, "realms %s/",
 140                                 rtnl_rtrealm_n2a(from, b1, sizeof(b1)));
 141                 }
 142                 fprintf(fp, "%s ",
 143                         rtnl_rtrealm_n2a(to, b1, sizeof(b1)));
 144         }
 145
 146         if (r->rtm_type == RTN_NAT) {
 147                 if (tb[RTA_GATEWAY]) {
 148                         fprintf(fp, "map-to %s ",
 149                                 format_host(r->rtm_family,
 150                                             RTA_PAYLOAD(tb[RTA_GATEWAY]),
 151                                             RTA_DATA(tb[RTA_GATEWAY]),
 152                                             abuf, sizeof(abuf)));
 153                 } else
 154                         fprintf(fp, "masquerade");
 155         } else if (r->rtm_type != RTN_UNICAST)
 156                 fputs(rtnl_rtntype_n2a(r->rtm_type, b1, sizeof(b1)), fp);
 157
 158         fputc('\n', fp);
 159         fflush(fp);
 160         return 0;
 161 }
 162
 163 /* Return value becomes exitcode. It's okay to not return at all */
 164 static int iprule_list(int argc, char **argv)
 165 {
 166         struct rtnl_handle rth;
 167         int af = preferred_family;
 168
 169         if (af == AF_UNSPEC)
 170                 af = AF_INET;
 171
 172         if (argc > 0) {
 173                 //bb_error_msg("\"rule show\" needs no arguments");
 174                 bb_warn_ignoring_args(argc);
 175                 return -1;
 176         }
 177
 178         xrtnl_open(&rth);
 179
 180         xrtnl_wilddump_request(&rth, af, RTM_GETRULE);
 181         xrtnl_dump_filter(&rth, print_rule, stdout);
 182
 183         return 0;
 184 }
 185
 186 /* Return value becomes exitcode. It's okay to not return at all */
 187 static int iprule_modify(int cmd, int argc, char **argv)
 188 {
 189         static const char keywords[] ALIGN1 =
 190                 "from\0""to\0""preference\0""order\0""priority\0"
 191                 "tos\0""fwmark\0""realms\0""table\0""lookup\0""dev\0"
 192                 "iif\0""nat\0""map-to\0""type\0""help\0";
 193         enum {
 194                 ARG_from = 1, ARG_to, ARG_preference, ARG_order, ARG_priority,
 195                 ARG_tos, ARG_fwmark, ARG_realms, ARG_table, ARG_lookup, ARG_dev,
 196                 ARG_iif, ARG_nat, ARG_map_to, ARG_type, ARG_help
 197         };
 198         bool table_ok = 0;
 199         struct rtnl_handle rth;
 200         struct {
 201                 struct nlmsghdr n;
 202                 struct rtmsg    r;
 203                 char            buf[1024];
 204         } req;
 205         smalluint key;
 206
 207         memset(&req, 0, sizeof(req));
 208
 209         req.n.nlmsg_type = cmd;
 210         req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
 211         req.n.nlmsg_flags = NLM_F_REQUEST;
 212         req.r.rtm_family = preferred_family;
 213         req.r.rtm_protocol = RTPROT_BOOT;
 214         req.r.rtm_scope = RT_SCOPE_UNIVERSE;
 215         req.r.rtm_table = 0;
 216         req.r.rtm_type = RTN_UNSPEC;
 217
 218         if (cmd == RTM_NEWRULE) {
 219                 req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;
 220                 req.r.rtm_type = RTN_UNICAST;
 221         }
 222
 223         while (argc > 0) {
 224                 key = index_in_substrings(keywords, *argv) + 1;
 225                 if (key == 0) /* no match found in keywords array, bail out. */
 226                         bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name);
 227                 if (key == ARG_from) {
 228                         inet_prefix dst;
 229                         NEXT_ARG();
 230                         get_prefix(&dst, *argv, req.r.rtm_family);
 231                         req.r.rtm_src_len = dst.bitlen;
 232                         addattr_l(&req.n, sizeof(req), RTA_SRC, &dst.data, dst.bytelen);
 233                 } else if (key == ARG_to) {
 234                         inet_prefix dst;
 235                         NEXT_ARG();
 236                         get_prefix(&dst, *argv, req.r.rtm_family);
 237                         req.r.rtm_dst_len = dst.bitlen;
 238                         addattr_l(&req.n, sizeof(req), RTA_DST, &dst.data, dst.bytelen);
 239                 } else if (key == ARG_preference ||
 240                            key == ARG_order ||
 241                            key == ARG_priority) {
 242                         uint32_t pref;
 243                         NEXT_ARG();
 244                         if (get_u32(&pref, *argv, 0))
 245                                 invarg(*argv, "preference");
 246                         addattr32(&req.n, sizeof(req), RTA_PRIORITY, pref);
 247                 } else if (key == ARG_tos) {
 248                         uint32_t tos;
 249                         NEXT_ARG();
 250                         if (rtnl_dsfield_a2n(&tos, *argv))
 251                                 invarg(*argv, "TOS");
 252                         req.r.rtm_tos = tos;
 253                 } else if (key == ARG_fwmark) {
 254                         uint32_t fwmark;
 255                         NEXT_ARG();
 256                         if (get_u32(&fwmark, *argv, 0))
 257                                 invarg(*argv, "fwmark");
 258                         addattr32(&req.n, sizeof(req), RTA_PROTOINFO, fwmark);
 259                 } else if (key == ARG_realms) {
 260                         uint32_t realm;
 261                         NEXT_ARG();
 262                         if (get_rt_realms(&realm, *argv))
 263                                 invarg(*argv, "realms");
 264                         addattr32(&req.n, sizeof(req), RTA_FLOW, realm);
 265                 } else if (key == ARG_table ||
 266                            key == ARG_lookup) {
 267                         uint32_t tid;
 268                         NEXT_ARG();
 269                         if (rtnl_rttable_a2n(&tid, *argv))
 270                                 invarg(*argv, "table ID");
 271                         req.r.rtm_table = tid;
 272                         table_ok = 1;
 273                 } else if (key == ARG_dev ||
 274                            key == ARG_iif) {
 275                         NEXT_ARG();
 276                         addattr_l(&req.n, sizeof(req), RTA_IIF, *argv, strlen(*argv)+1);
 277                 } else if (key == ARG_nat ||
 278                            key == ARG_map_to) {
 279                         NEXT_ARG();
 280                         addattr32(&req.n, sizeof(req), RTA_GATEWAY, get_addr32(*argv));
 281                         req.r.rtm_type = RTN_NAT;
 282                 } else {
 283                         int type;
 284
 285                         if (key == ARG_type) {
 286                                 NEXT_ARG();
 287                         }
 288                         if (key == ARG_help)
 289                                 bb_show_usage();
 290                         if (rtnl_rtntype_a2n(&type, *argv))
 291                                 invarg(*argv, "type");
 292                         req.r.rtm_type = type;
 293                 }
 294                 argc--;
 295                 argv++;
 296         }
 297
 298         if (req.r.rtm_family == AF_UNSPEC)
 299                 req.r.rtm_family = AF_INET;
 300
 301         if (!table_ok && cmd == RTM_NEWRULE)
 302                 req.r.rtm_table = RT_TABLE_MAIN;
 303
 304         xrtnl_open(&rth);
 305
 306         if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
 307                 return 2;
 308
 309         return 0;
 310 }
 311
 312 /* Return value becomes exitcode. It's okay to not return at all */
 313 int do_iprule(int argc, char **argv)
 314 {
 315         static const char ip_rule_commands[] ALIGN1 =
 316                 "add\0""delete\0""list\0""show\0";
 317         int cmd = 2; /* list */
 318
 319         if (argc < 1)
 320                 return iprule_list(0, NULL);
 321         if (*argv)
 322                 cmd = index_in_substrings(ip_rule_commands, *argv);
 323
 324         switch (cmd) {
 325                 case 0: /* add */
 326                         cmd = RTM_NEWRULE;
 327                         break;
 328                 case 1: /* delete */
 329                         cmd = RTM_DELRULE;
 330                         break;
 331                 case 2: /* list */
 332                 case 3: /* show */
 333                         return iprule_list(argc-1, argv+1);
 334                         break;
 335                 default:
 336                         bb_error_msg_and_die("unknown command %s", *argv);
 337         }
 338         return iprule_modify(cmd, argc-1, argv+1);
 339 }