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