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                         fprintf(fp, "%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, "0/%d", r->rtm_src_len);
  98         } else {
  99                 fprintf(fp, "all");
 100         }
 101         fprintf(fp, " ");
 102
 103         if (tb[RTA_DST]) {
 104                 if (r->rtm_dst_len != host_len) {
 105                         fprintf(fp, "to %s/%u ", rt_addr_n2a(r->rtm_family,
 106                                                          RTA_PAYLOAD(tb[RTA_DST]),
 107                                                          RTA_DATA(tb[RTA_DST]),
 108                                                          abuf, sizeof(abuf)),
 109                                 r->rtm_dst_len
 110                                 );
 111                 } else {
 112                         fprintf(fp, "to %s ", format_host(r->rtm_family,
 113                                                        RTA_PAYLOAD(tb[RTA_DST]),
 114                                                        RTA_DATA(tb[RTA_DST]),
 115                                                        abuf, sizeof(abuf)));
 116                 }
 117         } else if (r->rtm_dst_len) {
 118                 fprintf(fp, "to 0/%d ", r->rtm_dst_len);
 119         }
 120
 121         if (r->rtm_tos) {
 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 ", *(uint32_t*)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                 uint32_t to = *(uint32_t*)RTA_DATA(tb[RTA_FLOW]);
 137                 uint32_t 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         fputc('\n', fp);
 160         fflush(fp);
 161         return 0;
 162 }
 163
 164 /* Return value becomes exitcode. It's okay to not return at all */
 165 static int iprule_list(int argc, char **argv)
 166 {
 167         struct rtnl_handle rth;
 168         int af = preferred_family;
 169
 170         if (af == AF_UNSPEC)
 171                 af = AF_INET;
 172
 173         if (argc > 0) {
 174                 //bb_error_msg("\"rule show\" needs no arguments");
 175                 bb_warn_ignoring_args(argc);
 176                 return -1;
 177         }
 178
 179         xrtnl_open(&rth);
 180
 181         xrtnl_wilddump_request(&rth, af, RTM_GETRULE);
 182         xrtnl_dump_filter(&rth, print_rule, stdout);
 183
 184         return 0;
 185 }
 186
 187 /* Return value becomes exitcode. It's okay to not return at all */
 188 static int iprule_modify(int cmd, int argc, char **argv)
 189 {
 190         bool table_ok = 0;
 191         struct rtnl_handle rth;
 192         struct {
 193                 struct nlmsghdr n;
 194                 struct rtmsg    r;
 195                 char            buf[1024];
 196         } req;
 197         static const char * const keywords[] =
 198         { "from", "to", "preference", "order", "priority", "tos", "fwmark",
 199         "realms", "table", "lookup", "dev", "iif", "nat", "map-to", "type",
 200         "help", NULL};
 201         enum { ARG_from = 1, ARG_to, ARG_preference, ARG_order, ARG_priority,
 202         ARG_tos, ARG_fwmark, ARG_realms, ARG_table, ARG_lookup, ARG_dev,
 203         ARG_iif, ARG_nat, ARG_map_to, ARG_type, ARG_help };
 204         smalluint key;
 205
 206         memset(&req, 0, sizeof(req));
 207
 208         req.n.nlmsg_type = cmd;
 209         req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
 210         req.n.nlmsg_flags = NLM_F_REQUEST;
 211         req.r.rtm_family = preferred_family;
 212         req.r.rtm_protocol = RTPROT_BOOT;
 213         req.r.rtm_scope = RT_SCOPE_UNIVERSE;
 214         req.r.rtm_table = 0;
 215         req.r.rtm_type = RTN_UNSPEC;
 216
 217         if (cmd == RTM_NEWRULE) {
 218                 req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;
 219                 req.r.rtm_type = RTN_UNICAST;
 220         }
 221
 222         while (argc > 0) {
 223                 key = index_in_substr_array(keywords, *argv) + 1;
 224                 if (key == 0) /* no match found in keywords array, bail out. */
 225                         bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name);
 226                 if (key == ARG_from) {
 227                         inet_prefix dst;
 228                         NEXT_ARG();
 229                         get_prefix(&dst, *argv, req.r.rtm_family);
 230                         req.r.rtm_src_len = dst.bitlen;
 231                         addattr_l(&req.n, sizeof(req), RTA_SRC, &dst.data, dst.bytelen);
 232                 } else if (key == ARG_to) {
 233                         inet_prefix dst;
 234                         NEXT_ARG();
 235                         get_prefix(&dst, *argv, req.r.rtm_family);
 236                         req.r.rtm_dst_len = dst.bitlen;
 237                         addattr_l(&req.n, sizeof(req), RTA_DST, &dst.data, dst.bytelen);
 238                 } else if (key == ARG_preference ||
 239                            key == ARG_order ||
 240                            key == ARG_priority) {
 241                         uint32_t pref;
 242                         NEXT_ARG();
 243                         if (get_u32(&pref, *argv, 0))
 244                                 invarg(*argv, "preference");
 245                         addattr32(&req.n, sizeof(req), RTA_PRIORITY, pref);
 246                 } else if (key == ARG_tos) {
 247                         uint32_t tos;
 248                         NEXT_ARG();
 249                         if (rtnl_dsfield_a2n(&tos, *argv))
 250                                 invarg(*argv, "TOS");
 251                         req.r.rtm_tos = tos;
 252                 } else if (key == ARG_fwmark) {
 253                         uint32_t fwmark;
 254                         NEXT_ARG();
 255                         if (get_u32(&fwmark, *argv, 0))
 256                                 invarg(*argv, "fwmark");
 257                         addattr32(&req.n, sizeof(req), RTA_PROTOINFO, fwmark);
 258                 } else if (key == ARG_realms) {
 259                         uint32_t realm;
 260                         NEXT_ARG();
 261                         if (get_rt_realms(&realm, *argv))
 262                                 invarg(*argv, "realms");
 263                         addattr32(&req.n, sizeof(req), RTA_FLOW, realm);
 264                 } else if (key == ARG_table ||
 265                            key == ARG_lookup) {
 266                         uint32_t tid;
 267                         NEXT_ARG();
 268                         if (rtnl_rttable_a2n(&tid, *argv))
 269                                 invarg(*argv, "table ID");
 270                         req.r.rtm_table = tid;
 271                         table_ok = 1;
 272                 } else if (key == ARG_dev ||
 273                            key == ARG_iif) {
 274                         NEXT_ARG();
 275                         addattr_l(&req.n, sizeof(req), RTA_IIF, *argv, strlen(*argv)+1);
 276                 } else if (key == ARG_nat ||
 277                            key == ARG_map_to) {
 278                         NEXT_ARG();
 279                         addattr32(&req.n, sizeof(req), RTA_GATEWAY, get_addr32(*argv));
 280                         req.r.rtm_type = RTN_NAT;
 281                 } else {
 282                         int type;
 283
 284                         if (key == ARG_type) {
 285                                 NEXT_ARG();
 286                         }
 287                         if (key == ARG_help)
 288                                 bb_show_usage();
 289                         if (rtnl_rtntype_a2n(&type, *argv))
 290                                 invarg(*argv, "type");
 291                         req.r.rtm_type = type;
 292                 }
 293                 argc--;
 294                 argv++;
 295         }
 296
 297         if (req.r.rtm_family == AF_UNSPEC)
 298                 req.r.rtm_family = AF_INET;
 299
 300         if (!table_ok && cmd == RTM_NEWRULE)
 301                 req.r.rtm_table = RT_TABLE_MAIN;
 302
 303         xrtnl_open(&rth);
 304
 305         if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
 306                 return 2;
 307
 308         return 0;
 309 }
 310
 311 /* Return value becomes exitcode. It's okay to not return at all */
 312 int do_iprule(int argc, char **argv)
 313 {
 314         static const char * const ip_rule_commands[] =
 315                 {"add", "delete", "list", "show", 0};
 316         int cmd = 2; /* list */
 317
 318         if (argc < 1)
 319                 return iprule_list(0, NULL);
 320         if (*argv)
 321                 cmd = index_in_substr_array(ip_rule_commands, *argv);
 322
 323         switch (cmd) {
 324                 case 0: /* add */
 325                         cmd = RTM_NEWRULE;
 326                         break;
 327                 case 1: /* delete */
 328                         cmd = RTM_DELRULE;
 329                         break;
 330                 case 2: /* list */
 331                 case 3: /* show */
 332                         return iprule_list(argc-1, argv+1);
 333                         break;
 334                 default:
 335                         bb_error_msg_and_die("unknown command %s", *argv);
 336         }
 337         return iprule_modify(cmd, argc-1, argv+1);
 338 }