git.maemo.org Git - busybox4maemo/blob - 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(struct sockaddr_nl *who ATTRIBUTE_UNUSED,
  44                                         struct nlmsghdr *n, void *arg)
  45 {
  46         FILE *fp = (FILE*)arg;
  47         struct rtmsg *r = NLMSG_DATA(n);
  48         int len = n->nlmsg_len;
  49         int host_len = -1;
  50         struct rtattr * tb[RTA_MAX+1];
  51         char abuf[256];
  52         SPRINT_BUF(b1);
  53
  54         if (n->nlmsg_type != RTM_NEWRULE)
  55                 return 0;
  56
  57         len -= NLMSG_LENGTH(sizeof(*r));
  58         if (len < 0)
  59                 return -1;
  60
  61         memset(tb, 0, sizeof(tb));
  62         parse_rtattr(tb, RTA_MAX, RTM_RTA(r), len);
  63
  64         if (r->rtm_family == AF_INET)
  65                 host_len = 32;
  66         else if (r->rtm_family == AF_INET6)
  67                 host_len = 128;
  68 /*      else if (r->rtm_family == AF_DECnet)
  69                 host_len = 16;
  70         else if (r->rtm_family == AF_IPX)
  71                 host_len = 80;
  72 */
  73         if (tb[RTA_PRIORITY])
  74                 fprintf(fp, "%u:\t", *(unsigned*)RTA_DATA(tb[RTA_PRIORITY]));
  75         else
  76                 fprintf(fp, "0:\t");
  77
  78         fprintf(fp, "from ");
  79         if (tb[RTA_SRC]) {
  80                 if (r->rtm_src_len != host_len) {
  81                         fprintf(fp, "%s/%u", rt_addr_n2a(r->rtm_family,
  82                                                          RTA_PAYLOAD(tb[RTA_SRC]),
  83                                                          RTA_DATA(tb[RTA_SRC]),
  84                                                          abuf, sizeof(abuf)),
  85                                 r->rtm_src_len
  86                                 );
  87                 } else {
  88                         fputs(format_host(r->rtm_family,
  89                                                        RTA_PAYLOAD(tb[RTA_SRC]),
  90                                                        RTA_DATA(tb[RTA_SRC]),
  91                                                        abuf, sizeof(abuf)), fp);
  92                 }
  93         } else if (r->rtm_src_len) {
  94                 fprintf(fp, "0/%d", r->rtm_src_len);
  95         } else {
  96                 fprintf(fp, "all");
  97         }
  98         fprintf(fp, " ");
  99
 100         if (tb[RTA_DST]) {
 101                 if (r->rtm_dst_len != host_len) {
 102                         fprintf(fp, "to %s/%u ", rt_addr_n2a(r->rtm_family,
 103                                                          RTA_PAYLOAD(tb[RTA_DST]),
 104                                                          RTA_DATA(tb[RTA_DST]),
 105                                                          abuf, sizeof(abuf)),
 106                                 r->rtm_dst_len
 107                                 );
 108                 } else {
 109                         fprintf(fp, "to %s ", format_host(r->rtm_family,
 110                                                        RTA_PAYLOAD(tb[RTA_DST]),
 111                                                        RTA_DATA(tb[RTA_DST]),
 112                                                        abuf, sizeof(abuf)));
 113                 }
 114         } else if (r->rtm_dst_len) {
 115                 fprintf(fp, "to 0/%d ", r->rtm_dst_len);
 116         }
 117
 118         if (r->rtm_tos) {
 119                 fprintf(fp, "tos %s ", rtnl_dsfield_n2a(r->rtm_tos, b1, sizeof(b1)));
 120         }
 121         if (tb[RTA_PROTOINFO]) {
 122                 fprintf(fp, "fwmark %#x ", *(uint32_t*)RTA_DATA(tb[RTA_PROTOINFO]));
 123         }
 124
 125         if (tb[RTA_IIF]) {
 126                 fprintf(fp, "iif %s ", (char*)RTA_DATA(tb[RTA_IIF]));
 127         }
 128
 129         if (r->rtm_table)
 130                 fprintf(fp, "lookup %s ", rtnl_rttable_n2a(r->rtm_table, b1, sizeof(b1)));
 131
 132         if (tb[RTA_FLOW]) {
 133                 uint32_t to = *(uint32_t*)RTA_DATA(tb[RTA_FLOW]);
 134                 uint32_t from = to>>16;
 135                 to &= 0xFFFF;
 136                 if (from) {
 137                         fprintf(fp, "realms %s/",
 138                                 rtnl_rtrealm_n2a(from, b1, sizeof(b1)));
 139                 }
 140                 fprintf(fp, "%s ",
 141                         rtnl_rtrealm_n2a(to, b1, sizeof(b1)));
 142         }
 143
 144         if (r->rtm_type == RTN_NAT) {
 145                 if (tb[RTA_GATEWAY]) {
 146                         fprintf(fp, "map-to %s ",
 147                                 format_host(r->rtm_family,
 148                                             RTA_PAYLOAD(tb[RTA_GATEWAY]),
 149                                             RTA_DATA(tb[RTA_GATEWAY]),
 150                                             abuf, sizeof(abuf)));
 151                 } else
 152                         fprintf(fp, "masquerade");
 153         } else if (r->rtm_type != RTN_UNICAST)
 154                 fputs(rtnl_rtntype_n2a(r->rtm_type, b1, sizeof(b1)), fp);
 155
 156         fputc('\n', fp);
 157         fflush(fp);
 158         return 0;
 159 }
 160
 161 /* Return value becomes exitcode. It's okay to not return at all */
 162 static int iprule_list(char **argv)
 163 {
 164         struct rtnl_handle rth;
 165         int af = preferred_family;
 166
 167         if (af == AF_UNSPEC)
 168                 af = AF_INET;
 169
 170         if (*argv) {
 171                 //bb_error_msg("\"rule show\" needs no arguments");
 172                 bb_warn_ignoring_args(1);
 173                 return -1;
 174         }
 175
 176         xrtnl_open(&rth);
 177
 178         xrtnl_wilddump_request(&rth, af, RTM_GETRULE);
 179         xrtnl_dump_filter(&rth, print_rule, stdout);
 180
 181         return 0;
 182 }
 183
 184 /* Return value becomes exitcode. It's okay to not return at all */
 185 static int iprule_modify(int cmd, char **argv)
 186 {
 187         static const char keywords[] ALIGN1 =
 188                 "from\0""to\0""preference\0""order\0""priority\0"
 189                 "tos\0""fwmark\0""realms\0""table\0""lookup\0""dev\0"
 190                 "iif\0""nat\0""map-to\0""type\0""help\0";
 191         enum {
 192                 ARG_from = 1, ARG_to, ARG_preference, ARG_order, ARG_priority,
 193                 ARG_tos, ARG_fwmark, ARG_realms, ARG_table, ARG_lookup, ARG_dev,
 194                 ARG_iif, ARG_nat, ARG_map_to, ARG_type, ARG_help
 195         };
 196         bool table_ok = 0;
 197         struct rtnl_handle rth;
 198         struct {
 199                 struct nlmsghdr n;
 200                 struct rtmsg    r;
 201                 char            buf[1024];
 202         } req;
 203         smalluint key;
 204
 205         memset(&req, 0, sizeof(req));
 206
 207         req.n.nlmsg_type = cmd;
 208         req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
 209         req.n.nlmsg_flags = NLM_F_REQUEST;
 210         req.r.rtm_family = preferred_family;
 211         req.r.rtm_protocol = RTPROT_BOOT;
 212         req.r.rtm_scope = RT_SCOPE_UNIVERSE;
 213         req.r.rtm_table = 0;
 214         req.r.rtm_type = RTN_UNSPEC;
 215
 216         if (cmd == RTM_NEWRULE) {
 217                 req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;
 218                 req.r.rtm_type = RTN_UNICAST;
 219         }
 220
 221         while (*argv) {
 222                 key = index_in_substrings(keywords, *argv) + 1;
 223                 if (key == 0) /* no match found in keywords array, bail out. */
 224                         bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name);
 225                 if (key == ARG_from) {
 226                         inet_prefix dst;
 227                         NEXT_ARG();
 228                         get_prefix(&dst, *argv, req.r.rtm_family);
 229                         req.r.rtm_src_len = dst.bitlen;
 230                         addattr_l(&req.n, sizeof(req), RTA_SRC, &dst.data, dst.bytelen);
 231                 } else if (key == ARG_to) {
 232                         inet_prefix dst;
 233                         NEXT_ARG();
 234                         get_prefix(&dst, *argv, req.r.rtm_family);
 235                         req.r.rtm_dst_len = dst.bitlen;
 236                         addattr_l(&req.n, sizeof(req), RTA_DST, &dst.data, dst.bytelen);
 237                 } else if (key == ARG_preference ||
 238                            key == ARG_order ||
 239                            key == ARG_priority) {
 240                         uint32_t pref;
 241                         NEXT_ARG();
 242                         if (get_u32(&pref, *argv, 0))
 243                                 invarg(*argv, "preference");
 244                         addattr32(&req.n, sizeof(req), RTA_PRIORITY, pref);
 245                 } else if (key == ARG_tos) {
 246                         uint32_t tos;
 247                         NEXT_ARG();
 248                         if (rtnl_dsfield_a2n(&tos, *argv))
 249                                 invarg(*argv, "TOS");
 250                         req.r.rtm_tos = tos;
 251                 } else if (key == ARG_fwmark) {
 252                         uint32_t fwmark;
 253                         NEXT_ARG();
 254                         if (get_u32(&fwmark, *argv, 0))
 255                                 invarg(*argv, "fwmark");
 256                         addattr32(&req.n, sizeof(req), RTA_PROTOINFO, fwmark);
 257                 } else if (key == ARG_realms) {
 258                         uint32_t realm;
 259                         NEXT_ARG();
 260                         if (get_rt_realms(&realm, *argv))
 261                                 invarg(*argv, "realms");
 262                         addattr32(&req.n, sizeof(req), RTA_FLOW, realm);
 263                 } else if (key == ARG_table ||
 264                            key == ARG_lookup) {
 265                         uint32_t tid;
 266                         NEXT_ARG();
 267                         if (rtnl_rttable_a2n(&tid, *argv))
 268                                 invarg(*argv, "table ID");
 269                         req.r.rtm_table = tid;
 270                         table_ok = 1;
 271                 } else if (key == ARG_dev ||
 272                            key == ARG_iif) {
 273                         NEXT_ARG();
 274                         addattr_l(&req.n, sizeof(req), RTA_IIF, *argv, strlen(*argv)+1);
 275                 } else if (key == ARG_nat ||
 276                            key == ARG_map_to) {
 277                         NEXT_ARG();
 278                         addattr32(&req.n, sizeof(req), RTA_GATEWAY, get_addr32(*argv));
 279                         req.r.rtm_type = RTN_NAT;
 280                 } else {
 281                         int type;
 282
 283                         if (key == ARG_type) {
 284                                 NEXT_ARG();
 285                         }
 286                         if (key == ARG_help)
 287                                 bb_show_usage();
 288                         if (rtnl_rtntype_a2n(&type, *argv))
 289                                 invarg(*argv, "type");
 290                         req.r.rtm_type = type;
 291                 }
 292                 argv++;
 293         }
 294
 295         if (req.r.rtm_family == AF_UNSPEC)
 296                 req.r.rtm_family = AF_INET;
 297
 298         if (!table_ok && cmd == RTM_NEWRULE)
 299                 req.r.rtm_table = RT_TABLE_MAIN;
 300
 301         xrtnl_open(&rth);
 302
 303         if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
 304                 return 2;
 305
 306         return 0;
 307 }
 308
 309 /* Return value becomes exitcode. It's okay to not return at all */
 310 int do_iprule(char **argv)
 311 {
 312         static const char ip_rule_commands[] ALIGN1 =
 313                 "add\0""delete\0""list\0""show\0";
 314         int cmd = 2; /* list */
 315
 316         if (!*argv)
 317                 return iprule_list(argv);
 318
 319         cmd = index_in_substrings(ip_rule_commands, *argv);
 320         switch (cmd) {
 321                 case 0: /* add */
 322                         cmd = RTM_NEWRULE;
 323                         break;
 324                 case 1: /* delete */
 325                         cmd = RTM_DELRULE;
 326                         break;
 327                 case 2: /* list */
 328                 case 3: /* show */
 329                         return iprule_list(argv+1);
 330                         break;
 331                 default:
 332                         bb_error_msg_and_die("unknown command %s", *argv);
 333         }
 334         return iprule_modify(cmd, argv+1);
 335 }