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 #include <netinet/in.h>
  16 #include <netinet/ip.h>
  17 #include <arpa/inet.h>
  18
  19 /* from <linux/fib_rules.h>: */
  20 #define FRA_SUPPRESS_IFGROUP   13
  21 #define FRA_SUPPRESS_PREFIXLEN 14
  22
  23 #include "ip_common.h"  /* #include "libbb.h" is inside */
  24 #include "rt_names.h"
  25 #include "utils.h"
  26
  27 #include <linux/version.h>
  28 /* RTA_TABLE is not a define, can't test with ifdef. */
  29 /* As a proxy, test which kernels toolchain expects: */
  30 #define HAVE_RTA_TABLE (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,19))
  31
  32 /* If you add stuff here, update iprule_full_usage */
  33 static const char keywords[] ALIGN1 =
  34         "from\0""to\0""preference\0""order\0""priority\0"
  35         "tos\0""fwmark\0""realms\0""table\0""lookup\0"
  36         "suppress_prefixlength\0""suppress_ifgroup\0"
  37         "dev\0""iif\0""nat\0""map-to\0""type\0""help\0"
  38         ;
  39 #define keyword_preference            (keywords           + sizeof("from") + sizeof("to"))
  40 #define keyword_fwmark                (keyword_preference + sizeof("preference") + sizeof("order") + sizeof("priority") + sizeof("tos"))
  41 #define keyword_realms                (keyword_fwmark     + sizeof("fwmark"))
  42 #define keyword_suppress_prefixlength (keyword_realms     + sizeof("realms") + sizeof("table") + sizeof("lookup"))
  43 #define keyword_suppress_ifgroup      (keyword_suppress_prefixlength + sizeof("suppress_prefixlength"))
  44 enum {
  45         ARG_from = 1, ARG_to, ARG_preference, ARG_order, ARG_priority,
  46         ARG_tos, ARG_fwmark, ARG_realms, ARG_table, ARG_lookup,
  47         ARG_suppress_prefixlength, ARG_suppress_ifgroup,
  48         ARG_dev, ARG_iif, ARG_nat, ARG_map_to, ARG_type, ARG_help,
  49 };
  50
  51 static int FAST_FUNC print_rule(const struct sockaddr_nl *who UNUSED_PARAM,
  52                                         struct nlmsghdr *n, void *arg UNUSED_PARAM)
  53 {
  54         struct rtmsg *r = NLMSG_DATA(n);
  55         int len = n->nlmsg_len;
  56         int host_len = -1;
  57         struct rtattr * tb[RTA_MAX+1];
  58
  59         if (n->nlmsg_type != RTM_NEWRULE)
  60                 return 0;
  61
  62         len -= NLMSG_LENGTH(sizeof(*r));
  63         if (len < 0)
  64                 return -1;
  65
  66         //memset(tb, 0, sizeof(tb)); - parse_rtattr does this
  67         parse_rtattr(tb, RTA_MAX, RTM_RTA(r), len);
  68
  69         if (r->rtm_family == AF_INET)
  70                 host_len = 32;
  71         else if (r->rtm_family == AF_INET6)
  72                 host_len = 128;
  73 /*      else if (r->rtm_family == AF_DECnet)
  74                 host_len = 16;
  75         else if (r->rtm_family == AF_IPX)
  76                 host_len = 80;
  77 */
  78         printf("%u:\t", tb[RTA_PRIORITY] ?
  79                                         *(unsigned*)RTA_DATA(tb[RTA_PRIORITY])
  80                                         : 0);
  81         printf("from ");
  82         if (tb[RTA_SRC]) {
  83                 if (r->rtm_src_len != host_len) {
  84                         printf("%s/%u",
  85                                 rt_addr_n2a(r->rtm_family, RTA_DATA(tb[RTA_SRC])),
  86                                 r->rtm_src_len
  87                         );
  88                 } else {
  89                         fputs(format_host(r->rtm_family,
  90                                                 RTA_PAYLOAD(tb[RTA_SRC]),
  91                                                 RTA_DATA(tb[RTA_SRC])),
  92                                 stdout
  93                         );
  94                 }
  95         } else if (r->rtm_src_len) {
  96                 printf("0/%d", r->rtm_src_len);
  97         } else {
  98                 printf("all");
  99         }
 100         bb_putchar(' ');
 101
 102         if (tb[RTA_DST]) {
 103                 if (r->rtm_dst_len != host_len) {
 104                         printf("to %s/%u ", rt_addr_n2a(r->rtm_family,
 105                                                          RTA_DATA(tb[RTA_DST])),
 106                                 r->rtm_dst_len
 107                                 );
 108                 } else {
 109                         printf("to %s ", format_host(r->rtm_family,
 110                                                        RTA_PAYLOAD(tb[RTA_DST]),
 111                                                        RTA_DATA(tb[RTA_DST])));
 112                 }
 113         } else if (r->rtm_dst_len) {
 114                 printf("to 0/%d ", r->rtm_dst_len);
 115         }
 116
 117         if (r->rtm_tos) {
 118                 printf("tos %s ", rtnl_dsfield_n2a(r->rtm_tos));
 119         }
 120         if (tb[RTA_PROTOINFO]) {
 121                 printf("fwmark %#x ", *(uint32_t*)RTA_DATA(tb[RTA_PROTOINFO]));
 122         }
 123
 124         if (tb[RTA_IIF]) {
 125                 printf("iif %s ", (char*)RTA_DATA(tb[RTA_IIF]));
 126         }
 127
 128 #if HAVE_RTA_TABLE
 129         if (tb[RTA_TABLE])
 130                 printf("lookup %s ", rtnl_rttable_n2a(*(uint32_t*)RTA_DATA(tb[RTA_TABLE])));
 131         else
 132 #endif
 133         if (r->rtm_table)
 134                 printf("lookup %s ", rtnl_rttable_n2a(r->rtm_table));
 135
 136         if (tb[FRA_SUPPRESS_PREFIXLEN]) {
 137                 int pl = *(uint32_t*)RTA_DATA(tb[FRA_SUPPRESS_PREFIXLEN]);
 138                 if (pl != -1)
 139                         printf("%s %d ", keyword_suppress_prefixlength, pl);
 140         }
 141         if (tb[FRA_SUPPRESS_IFGROUP]) {
 142                 int grp = *(uint32_t*)RTA_DATA(tb[FRA_SUPPRESS_IFGROUP]);
 143                 if (grp != -1)
 144                         printf("%s %d ", keyword_suppress_ifgroup, grp);
 145         }
 146
 147         if (tb[RTA_FLOW]) {
 148                 uint32_t to = *(uint32_t*)RTA_DATA(tb[RTA_FLOW]);
 149                 uint32_t from = to>>16;
 150                 to &= 0xFFFF;
 151                 if (from) {
 152                         printf("realms %s/",
 153                                 rtnl_rtrealm_n2a(from));
 154                 }
 155                 printf("%s ",
 156                         rtnl_rtrealm_n2a(to));
 157         }
 158
 159         if (r->rtm_type == RTN_NAT) {
 160                 if (tb[RTA_GATEWAY]) {
 161                         printf("map-to %s ",
 162                                 format_host(r->rtm_family,
 163                                             RTA_PAYLOAD(tb[RTA_GATEWAY]),
 164                                             RTA_DATA(tb[RTA_GATEWAY]))
 165                         );
 166                 } else
 167                         printf("masquerade");
 168         } else if (r->rtm_type != RTN_UNICAST)
 169                 fputs(rtnl_rtntype_n2a(r->rtm_type), stdout);
 170
 171         bb_putchar('\n');
 172         /*fflush_all();*/
 173         return 0;
 174 }
 175
 176 /* Return value becomes exitcode. It's okay to not return at all */
 177 static int iprule_list(char **argv)
 178 {
 179         struct rtnl_handle rth;
 180         int af = preferred_family;
 181
 182         if (af == AF_UNSPEC)
 183                 af = AF_INET;
 184
 185         if (*argv) {
 186                 //bb_error_msg("\"rule show\" needs no arguments");
 187                 bb_warn_ignoring_args(*argv);
 188                 return -1;
 189         }
 190
 191         xrtnl_open(&rth);
 192
 193         xrtnl_wilddump_request(&rth, af, RTM_GETRULE);
 194         xrtnl_dump_filter(&rth, print_rule, NULL);
 195
 196         return 0;
 197 }
 198
 199 /* Return value becomes exitcode. It's okay to not return at all */
 200 static int iprule_modify(int cmd, char **argv)
 201 {
 202         bool table_ok = 0;
 203         struct rtnl_handle rth;
 204         struct {
 205                 struct nlmsghdr n;
 206                 struct rtmsg    r;
 207                 char            buf[1024];
 208         } req;
 209         smalluint key;
 210
 211         memset(&req, 0, sizeof(req));
 212
 213         req.n.nlmsg_type = cmd;
 214         req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
 215         req.n.nlmsg_flags = NLM_F_REQUEST;
 216         req.r.rtm_family = preferred_family;
 217         req.r.rtm_protocol = RTPROT_BOOT;
 218         if (RT_SCOPE_UNIVERSE != 0)
 219                 req.r.rtm_scope = RT_SCOPE_UNIVERSE;
 220         /*req.r.rtm_table = 0; - already is */
 221         if (RTN_UNSPEC != 0)
 222                 req.r.rtm_type = RTN_UNSPEC;
 223
 224         if (cmd == RTM_NEWRULE) {
 225                 req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;
 226                 req.r.rtm_type = RTN_UNICAST;
 227         }
 228
 229         while (*argv) {
 230                 key = index_in_substrings(keywords, *argv) + 1;
 231                 if (key == 0) /* no match found in keywords array, bail out. */
 232                         invarg_1_to_2(*argv, applet_name);
 233                 if (key == ARG_from) {
 234                         inet_prefix dst;
 235                         NEXT_ARG();
 236                         get_prefix(&dst, *argv, req.r.rtm_family);
 237                         req.r.rtm_src_len = dst.bitlen;
 238                         addattr_l(&req.n, sizeof(req), RTA_SRC, &dst.data, dst.bytelen);
 239                 } else if (key == ARG_to) {
 240                         inet_prefix dst;
 241                         NEXT_ARG();
 242                         get_prefix(&dst, *argv, req.r.rtm_family);
 243                         req.r.rtm_dst_len = dst.bitlen;
 244                         addattr_l(&req.n, sizeof(req), RTA_DST, &dst.data, dst.bytelen);
 245                 } else if (key == ARG_preference ||
 246                            key == ARG_order ||
 247                            key == ARG_priority
 248                 ) {
 249                         uint32_t pref;
 250                         NEXT_ARG();
 251                         pref = get_u32(*argv, keyword_preference);
 252                         addattr32(&req.n, sizeof(req), RTA_PRIORITY, pref);
 253                 } else if (key == ARG_tos) {
 254                         uint32_t tos;
 255                         NEXT_ARG();
 256                         if (rtnl_dsfield_a2n(&tos, *argv))
 257                                 invarg_1_to_2(*argv, "TOS");
 258                         req.r.rtm_tos = tos;
 259                 } else if (key == ARG_fwmark) {
 260                         uint32_t fwmark;
 261                         NEXT_ARG();
 262                         fwmark = get_u32(*argv, keyword_fwmark);
 263                         addattr32(&req.n, sizeof(req), RTA_PROTOINFO, fwmark);
 264                 } else if (key == ARG_realms) {
 265                         uint32_t realm;
 266                         NEXT_ARG();
 267                         if (get_rt_realms(&realm, *argv))
 268                                 invarg_1_to_2(*argv, keyword_realms);
 269                         addattr32(&req.n, sizeof(req), RTA_FLOW, realm);
 270                 } else if (key == ARG_table ||
 271                            key == ARG_lookup
 272                 ) {
 273                         uint32_t tid;
 274                         NEXT_ARG();
 275                         if (rtnl_rttable_a2n(&tid, *argv))
 276                                 invarg_1_to_2(*argv, "table ID");
 277
 278 #if HAVE_RTA_TABLE
 279                         if (tid > 255) {
 280                                 req.r.rtm_table = RT_TABLE_UNSPEC;
 281                                 addattr32(&req.n, sizeof(req), RTA_TABLE, tid);
 282                         } else
 283 #endif
 284                                 req.r.rtm_table = tid;
 285
 286                         table_ok = 1;
 287                 } else if (key == ARG_suppress_prefixlength) {
 288                         int prefix_length;
 289                         NEXT_ARG();
 290                         prefix_length = get_u32(*argv, keyword_suppress_prefixlength);
 291                         addattr32(&req.n, sizeof(req), FRA_SUPPRESS_PREFIXLEN, prefix_length);
 292                 } else if (key == ARG_suppress_ifgroup) {
 293                         int grp;
 294                         NEXT_ARG();
 295                         grp = get_u32(*argv, keyword_suppress_ifgroup);
 296                         addattr32(&req.n, sizeof(req), FRA_SUPPRESS_IFGROUP, grp);
 297                 } else if (key == ARG_dev ||
 298                            key == ARG_iif
 299                 ) {
 300                         NEXT_ARG();
 301                         addattr_l(&req.n, sizeof(req), RTA_IIF, *argv, strlen(*argv)+1);
 302                 } else if (key == ARG_nat ||
 303                            key == ARG_map_to
 304                 ) {
 305                         NEXT_ARG();
 306                         addattr32(&req.n, sizeof(req), RTA_GATEWAY, get_addr32(*argv));
 307                         req.r.rtm_type = RTN_NAT;
 308                 } else {
 309                         int type;
 310
 311                         if (key == ARG_type) {
 312                                 NEXT_ARG();
 313                         }
 314                         if (key == ARG_help)
 315                                 bb_show_usage();
 316                         if (rtnl_rtntype_a2n(&type, *argv))
 317                                 invarg_1_to_2(*argv, "type");
 318                         req.r.rtm_type = type;
 319                 }
 320                 argv++;
 321         }
 322
 323         if (req.r.rtm_family == AF_UNSPEC)
 324                 req.r.rtm_family = AF_INET;
 325
 326         if (!table_ok && cmd == RTM_NEWRULE)
 327                 req.r.rtm_table = RT_TABLE_MAIN;
 328
 329         xrtnl_open(&rth);
 330
 331         if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
 332                 return 2;
 333
 334         return 0;
 335 }
 336
 337 /* Return value becomes exitcode. It's okay to not return at all */
 338 int FAST_FUNC do_iprule(char **argv)
 339 {
 340         static const char ip_rule_commands[] ALIGN1 =
 341                 "add\0""delete\0""list\0""show\0";
 342         if (*argv) {
 343                 int cmd = index_in_substrings(ip_rule_commands, *argv);
 344                 if (cmd < 0)
 345                         invarg_1_to_2(*argv, applet_name);
 346                 argv++;
 347                 if (cmd < 2)
 348                         return iprule_modify((cmd == 0) ? RTM_NEWRULE : RTM_DELRULE, argv);
 349         }
 350         return iprule_list(argv);
 351 }