ip/ipneigh.c

   1 /*
   2  * ipneigh.c            "ip neigh".
   3  *
   4  *              This program is free software; you can redistribute it and/or
   5  *              modify it under the terms of the GNU General Public License
   6  *              as published by the Free Software Foundation; either version
   7  *              2 of the License, or (at your option) any later version.
   8  *
   9  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  10  *
  11  */
  12
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <unistd.h>
  16 #include <syslog.h>
  17 #include <fcntl.h>
  18 #include <string.h>
  19 #include <sys/time.h>
  20 #include <sys/socket.h>
  21 #include <netinet/in.h>
  22 #include <netinet/ip.h>
  23
  24 #include "rt_names.h"
  25 #include "utils.h"
  26 #include "ip_common.h"
  27
  28 #define NUD_VALID       (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE|NUD_PROBE|NUD_STALE|NUD_DELAY)
  29 #define MAX_ROUNDS      10
  30
  31 static struct
  32 {
  33         int family;
  34         int index;
  35         int state;
  36         int unused_only;
  37         inet_prefix pfx;
  38         int flushed;
  39         char *flushb;
  40         int flushp;
  41         int flushe;
  42 } filter;
  43
  44 static void usage(void) __attribute__((noreturn));
  45
  46 static void usage(void)
  47 {
  48         fprintf(stderr, "Usage: ip neigh { add | del | change | replace } { ADDR [ lladdr LLADDR ]\n"
  49                         "          [ nud { permanent | noarp | stale | reachable } ]\n"
  50                         "          | proxy ADDR } [ dev DEV ]\n");
  51         fprintf(stderr, "       ip neigh {show|flush} [ to PREFIX ] [ dev DEV ] [ nud STATE ]\n");
  52         exit(-1);
  53 }
  54
  55 int nud_state_a2n(unsigned *state, char *arg)
  56 {
  57         if (matches(arg, "permanent") == 0)
  58                 *state = NUD_PERMANENT;
  59         else if (matches(arg, "reachable") == 0)
  60                 *state = NUD_REACHABLE;
  61         else if (strcmp(arg, "noarp") == 0)
  62                 *state = NUD_NOARP;
  63         else if (strcmp(arg, "none") == 0)
  64                 *state = NUD_NONE;
  65         else if (strcmp(arg, "stale") == 0)
  66                 *state = NUD_STALE;
  67         else if (strcmp(arg, "incomplete") == 0)
  68                 *state = NUD_INCOMPLETE;
  69         else if (strcmp(arg, "delay") == 0)
  70                 *state = NUD_DELAY;
  71         else if (strcmp(arg, "probe") == 0)
  72                 *state = NUD_PROBE;
  73         else if (matches(arg, "failed") == 0)
  74                 *state = NUD_FAILED;
  75         else {
  76                 if (get_unsigned(state, arg, 0))
  77                         return -1;
  78                 if (*state>=0x100 || (*state&((*state)-1)))
  79                         return -1;
  80         }
  81         return 0;
  82 }
  83
  84 static int flush_update(void)
  85 {
  86         if (rtnl_send_check(&rth, filter.flushb, filter.flushp) < 0) {
  87                 perror("Failed to send flush request");
  88                 return -1;
  89         }
  90         filter.flushp = 0;
  91         return 0;
  92 }
  93
  94
  95 static int ipneigh_modify(int cmd, int flags, int argc, char **argv)
  96 {
  97         struct {
  98                 struct nlmsghdr         n;
  99                 struct ndmsg            ndm;
 100                 char                    buf[256];
 101         } req;
 102         char  *d = NULL;
 103         int dst_ok = 0;
 104         int lladdr_ok = 0;
 105         char * lla = NULL;
 106         inet_prefix dst;
 107
 108         memset(&req, 0, sizeof(req));
 109
 110         req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndmsg));
 111         req.n.nlmsg_flags = NLM_F_REQUEST|flags;
 112         req.n.nlmsg_type = cmd;
 113         req.ndm.ndm_family = preferred_family;
 114         req.ndm.ndm_state = NUD_PERMANENT;
 115
 116         while (argc > 0) {
 117                 if (matches(*argv, "lladdr") == 0) {
 118                         NEXT_ARG();
 119                         if (lladdr_ok)
 120                                 duparg("lladdr", *argv);
 121                         lla = *argv;
 122                         lladdr_ok = 1;
 123                 } else if (strcmp(*argv, "nud") == 0) {
 124                         unsigned state;
 125                         NEXT_ARG();
 126                         if (nud_state_a2n(&state, *argv))
 127                                 invarg("nud state is bad", *argv);
 128                         req.ndm.ndm_state = state;
 129                 } else if (matches(*argv, "proxy") == 0) {
 130                         NEXT_ARG();
 131                         if (matches(*argv, "help") == 0)
 132                                 usage();
 133                         if (dst_ok)
 134                                 duparg("address", *argv);
 135                         get_addr(&dst, *argv, preferred_family);
 136                         dst_ok = 1;
 137                         req.ndm.ndm_flags |= NTF_PROXY;
 138                 } else if (strcmp(*argv, "dev") == 0) {
 139                         NEXT_ARG();
 140                         d = *argv;
 141                 } else {
 142                         if (strcmp(*argv, "to") == 0) {
 143                                 NEXT_ARG();
 144                         }
 145                         if (matches(*argv, "help") == 0) {
 146                                 NEXT_ARG();
 147                         }
 148                         if (dst_ok)
 149                                 duparg2("to", *argv);
 150                         get_addr(&dst, *argv, preferred_family);
 151                         dst_ok = 1;
 152                 }
 153                 argc--; argv++;
 154         }
 155         if (d == NULL || !dst_ok || dst.family == AF_UNSPEC) {
 156                 fprintf(stderr, "Device and destination are required arguments.\n");
 157                 exit(-1);
 158         }
 159         req.ndm.ndm_family = dst.family;
 160         addattr_l(&req.n, sizeof(req), NDA_DST, &dst.data, dst.bytelen);
 161
 162         if (lla && strcmp(lla, "null")) {
 163                 char llabuf[20];
 164                 int l;
 165
 166                 l = ll_addr_a2n(llabuf, sizeof(llabuf), lla);
 167                 addattr_l(&req.n, sizeof(req), NDA_LLADDR, llabuf, l);
 168         }
 169
 170         ll_init_map(&rth);
 171
 172         if ((req.ndm.ndm_ifindex = ll_name_to_index(d)) == 0) {
 173                 fprintf(stderr, "Cannot find device \"%s\"\n", d);
 174                 return -1;
 175         }
 176
 177         if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
 178                 exit(2);
 179
 180         return 0;
 181 }
 182
 183
 184 int print_neigh(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
 185 {
 186         FILE *fp = (FILE*)arg;
 187         struct ndmsg *r = NLMSG_DATA(n);
 188         int len = n->nlmsg_len;
 189         struct rtattr * tb[NDA_MAX+1];
 190         char abuf[256];
 191
 192         if (n->nlmsg_type != RTM_NEWNEIGH && n->nlmsg_type != RTM_DELNEIGH) {
 193                 fprintf(stderr, "Not RTM_NEWNEIGH: %08x %08x %08x\n",
 194                         n->nlmsg_len, n->nlmsg_type, n->nlmsg_flags);
 195
 196                 return 0;
 197         }
 198         len -= NLMSG_LENGTH(sizeof(*r));
 199         if (len < 0) {
 200                 fprintf(stderr, "BUG: wrong nlmsg len %d\n", len);
 201                 return -1;
 202         }
 203
 204         if (filter.flushb && n->nlmsg_type != RTM_NEWNEIGH)
 205                 return 0;
 206
 207         if (filter.family && filter.family != r->ndm_family)
 208                 return 0;
 209         if (filter.index && filter.index != r->ndm_ifindex)
 210                 return 0;
 211         if (!(filter.state&r->ndm_state) &&
 212             (r->ndm_state || !(filter.state&0x100)) &&
 213              (r->ndm_family != AF_DECnet))
 214                 return 0;
 215
 216         parse_rtattr(tb, NDA_MAX, NDA_RTA(r), n->nlmsg_len - NLMSG_LENGTH(sizeof(*r)));
 217
 218         if (tb[NDA_DST]) {
 219                 if (filter.pfx.family) {
 220                         inet_prefix dst;
 221                         memset(&dst, 0, sizeof(dst));
 222                         dst.family = r->ndm_family;
 223                         memcpy(&dst.data, RTA_DATA(tb[NDA_DST]), RTA_PAYLOAD(tb[NDA_DST]));
 224                         if (inet_addr_match(&dst, &filter.pfx, filter.pfx.bitlen))
 225                                 return 0;
 226                 }
 227         }
 228         if (filter.unused_only && tb[NDA_CACHEINFO]) {
 229                 struct nda_cacheinfo *ci = RTA_DATA(tb[NDA_CACHEINFO]);
 230                 if (ci->ndm_refcnt)
 231                         return 0;
 232         }
 233
 234         if (filter.flushb) {
 235                 struct nlmsghdr *fn;
 236                 if (NLMSG_ALIGN(filter.flushp) + n->nlmsg_len > filter.flushe) {
 237                         if (flush_update())
 238                                 return -1;
 239                 }
 240                 fn = (struct nlmsghdr*)(filter.flushb + NLMSG_ALIGN(filter.flushp));
 241                 memcpy(fn, n, n->nlmsg_len);
 242                 fn->nlmsg_type = RTM_DELNEIGH;
 243                 fn->nlmsg_flags = NLM_F_REQUEST;
 244                 fn->nlmsg_seq = ++rth.seq;
 245                 filter.flushp = (((char*)fn) + n->nlmsg_len) - filter.flushb;
 246                 filter.flushed++;
 247                 if (show_stats < 2)
 248                         return 0;
 249         }
 250
 251         if (tb[NDA_DST]) {
 252                 fprintf(fp, "%s ",
 253                         format_host(r->ndm_family,
 254                                     RTA_PAYLOAD(tb[NDA_DST]),
 255                                     RTA_DATA(tb[NDA_DST]),
 256                                     abuf, sizeof(abuf)));
 257         }
 258         if (!filter.index && r->ndm_ifindex)
 259                 fprintf(fp, "dev %s ", ll_index_to_name(r->ndm_ifindex));
 260         if (tb[NDA_LLADDR]) {
 261                 SPRINT_BUF(b1);
 262                 fprintf(fp, "lladdr %s", ll_addr_n2a(RTA_DATA(tb[NDA_LLADDR]),
 263                                               RTA_PAYLOAD(tb[NDA_LLADDR]),
 264                                               ll_index_to_type(r->ndm_ifindex),
 265                                               b1, sizeof(b1)));
 266         }
 267         if (r->ndm_flags & NTF_ROUTER) {
 268                 fprintf(fp, " router");
 269         }
 270         if (tb[NDA_CACHEINFO] && show_stats) {
 271                 struct nda_cacheinfo *ci = RTA_DATA(tb[NDA_CACHEINFO]);
 272                 int hz = get_user_hz();
 273
 274                 if (ci->ndm_refcnt)
 275                         printf(" ref %d", ci->ndm_refcnt);
 276                 fprintf(fp, " used %d/%d/%d", ci->ndm_used/hz,
 277                        ci->ndm_confirmed/hz, ci->ndm_updated/hz);
 278         }
 279
 280         if (tb[NDA_PROBES] && show_stats) {
 281                 __u32 p = *(__u32 *) RTA_DATA(tb[NDA_PROBES]);
 282                 fprintf(fp, " probes %u", p);
 283         }
 284
 285         if (r->ndm_state) {
 286                 int nud = r->ndm_state;
 287                 fprintf(fp, " ");
 288
 289 #define PRINT_FLAG(f) if (nud & NUD_##f) { \
 290         nud &= ~NUD_##f; fprintf(fp, #f "%s", nud ? "," : ""); }
 291                 PRINT_FLAG(INCOMPLETE);
 292                 PRINT_FLAG(REACHABLE);
 293                 PRINT_FLAG(STALE);
 294                 PRINT_FLAG(DELAY);
 295                 PRINT_FLAG(PROBE);
 296                 PRINT_FLAG(FAILED);
 297                 PRINT_FLAG(NOARP);
 298                 PRINT_FLAG(PERMANENT);
 299 #undef PRINT_FLAG
 300         }
 301         fprintf(fp, "\n");
 302
 303         fflush(fp);
 304         return 0;
 305 }
 306
 307 void ipneigh_reset_filter()
 308 {
 309         memset(&filter, 0, sizeof(filter));
 310         filter.state = ~0;
 311 }
 312
 313 int do_show_or_flush(int argc, char **argv, int flush)
 314 {
 315         char *filter_dev = NULL;
 316         int state_given = 0;
 317
 318         ipneigh_reset_filter();
 319
 320         if (!filter.family)
 321                 filter.family = preferred_family;
 322
 323         if (flush) {
 324                 if (argc <= 0) {
 325                         fprintf(stderr, "Flush requires arguments.\n");
 326                         return -1;
 327                 }
 328                 filter.state = ~(NUD_PERMANENT|NUD_NOARP);
 329         } else
 330                 filter.state = 0xFF & ~NUD_NOARP;
 331
 332         while (argc > 0) {
 333                 if (strcmp(*argv, "dev") == 0) {
 334                         NEXT_ARG();
 335                         if (filter_dev)
 336                                 duparg("dev", *argv);
 337                         filter_dev = *argv;
 338                 } else if (strcmp(*argv, "unused") == 0) {
 339                         filter.unused_only = 1;
 340                 } else if (strcmp(*argv, "nud") == 0) {
 341                         unsigned state;
 342                         NEXT_ARG();
 343                         if (!state_given) {
 344                                 state_given = 1;
 345                                 filter.state = 0;
 346                         }
 347                         if (nud_state_a2n(&state, *argv)) {
 348                                 if (strcmp(*argv, "all") != 0)
 349                                         invarg("nud state is bad", *argv);
 350                                 state = ~0;
 351                                 if (flush)
 352                                         state &= ~NUD_NOARP;
 353                         }
 354                         if (state == 0)
 355                                 state = 0x100;
 356                         filter.state |= state;
 357                 } else {
 358                         if (strcmp(*argv, "to") == 0) {
 359                                 NEXT_ARG();
 360                         }
 361                         if (matches(*argv, "help") == 0)
 362                                 usage();
 363                         get_prefix(&filter.pfx, *argv, filter.family);
 364                         if (filter.family == AF_UNSPEC)
 365                                 filter.family = filter.pfx.family;
 366                 }
 367                 argc--; argv++;
 368         }
 369
 370         ll_init_map(&rth);
 371
 372         if (filter_dev) {
 373                 if ((filter.index = ll_name_to_index(filter_dev)) == 0) {
 374                         fprintf(stderr, "Cannot find device \"%s\"\n", filter_dev);
 375                         return -1;
 376                 }
 377         }
 378
 379         if (flush) {
 380                 int round = 0;
 381                 char flushb[4096-512];
 382
 383                 filter.flushb = flushb;
 384                 filter.flushp = 0;
 385                 filter.flushe = sizeof(flushb);
 386                 filter.state &= ~NUD_FAILED;
 387
 388                 while (round < MAX_ROUNDS) {
 389                         if (rtnl_wilddump_request(&rth, filter.family, RTM_GETNEIGH) < 0) {
 390                                 perror("Cannot send dump request");
 391                                 exit(1);
 392                         }
 393                         filter.flushed = 0;
 394                         if (rtnl_dump_filter(&rth, print_neigh, stdout, NULL, NULL) < 0) {
 395                                 fprintf(stderr, "Flush terminated\n");
 396                                 exit(1);
 397                         }
 398                         if (filter.flushed == 0) {
 399                                 if (show_stats) {
 400                                         if (round == 0)
 401                                                 printf("Nothing to flush.\n");
 402                                         else
 403                                                 printf("*** Flush is complete after %d round%s ***\n", round, round>1?"s":"");
 404                                 }
 405                                 fflush(stdout);
 406                                 return 0;
 407                         }
 408                         round++;
 409                         if (flush_update() < 0)
 410                                 exit(1);
 411                         if (show_stats) {
 412                                 printf("\n*** Round %d, deleting %d entries ***\n", round, filter.flushed);
 413                                 fflush(stdout);
 414                         }
 415                 }
 416                 printf("*** Flush not complete bailing out after %d rounds\n",
 417                         MAX_ROUNDS);
 418                 return 1;
 419         }
 420
 421         if (rtnl_wilddump_request(&rth, filter.family, RTM_GETNEIGH) < 0) {
 422                 perror("Cannot send dump request");
 423                 exit(1);
 424         }
 425
 426         if (rtnl_dump_filter(&rth, print_neigh, stdout, NULL, NULL) < 0) {
 427                 fprintf(stderr, "Dump terminated\n");
 428                 exit(1);
 429         }
 430
 431         return 0;
 432 }
 433
 434 int do_ipneigh(int argc, char **argv)
 435 {
 436         if (argc > 0) {
 437                 if (matches(*argv, "add") == 0)
 438                         return ipneigh_modify(RTM_NEWNEIGH, NLM_F_CREATE|NLM_F_EXCL, argc-1, argv+1);
 439                 if (matches(*argv, "change") == 0 ||
 440                     strcmp(*argv, "chg") == 0)
 441                         return ipneigh_modify(RTM_NEWNEIGH, NLM_F_REPLACE, argc-1, argv+1);
 442                 if (matches(*argv, "replace") == 0)
 443                         return ipneigh_modify(RTM_NEWNEIGH, NLM_F_CREATE|NLM_F_REPLACE, argc-1, argv+1);
 444                 if (matches(*argv, "delete") == 0)
 445                         return ipneigh_modify(RTM_DELNEIGH, 0, argc-1, argv+1);
 446                 if (matches(*argv, "get") == 0) {
 447                         fprintf(stderr, "Sorry, \"neigh get\" is not implemented :-(\n");
 448                         return -1;
 449                 }
 450                 if (matches(*argv, "show") == 0 ||
 451                     matches(*argv, "lst") == 0 ||
 452                     matches(*argv, "list") == 0)
 453                         return do_show_or_flush(argc-1, argv+1, 0);
 454                 if (matches(*argv, "flush") == 0)
 455                         return do_show_or_flush(argc-1, argv+1, 1);
 456                 if (matches(*argv, "help") == 0)
 457                         usage();
 458         } else
 459                 return do_show_or_flush(0, NULL, 0);
 460
 461         fprintf(stderr, "Command \"%s\" is unknown, try \"ip neigh help\".\n", *argv);
 462         exit(-1);
 463 }