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  * Changes:
  13  *
  14  * Rani Assaf <rani@magic.metawire.com> 980929: resolve addresses
  15  */
  16
  17 #include <stdio.h>
  18 #include <stdlib.h>
  19 #include <unistd.h>
  20 #include <syslog.h>
  21 #include <fcntl.h>
  22 #include <string.h>
  23 #include <sys/time.h>
  24 #include <net/if.h>
  25 #include <sys/socket.h>
  26 #include <netinet/in.h>
  27 #include <netinet/ip.h>
  28
  29 #include "rt_names.h"
  30 #include "utils.h"
  31 #include "ip_common.h"
  32
  33 #define NUD_VALID       (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE|NUD_PROBE|NUD_STALE|NUD_DELAY)
  34 #define MAX_ROUNDS      10
  35
  36 static struct
  37 {
  38         int family;
  39         int index;
  40         int state;
  41         int unused_only;
  42         inet_prefix pfx;
  43         int flushed;
  44         char *flushb;
  45         int flushp;
  46         int flushe;
  47 } filter;
  48
  49 static void usage(void) __attribute__((noreturn));
  50
  51 static void usage(void)
  52 {
  53         fprintf(stderr, "Usage: ip neigh { add | del | change | replace } { ADDR [ lladdr LLADDR ]\n"
  54                         "          [ nud { permanent | noarp | stale | reachable } ]\n"
  55                         "          | proxy ADDR } [ dev DEV ]\n");
  56         fprintf(stderr, "       ip neigh {show|flush} [ to PREFIX ] [ dev DEV ] [ nud STATE ]\n");
  57         exit(-1);
  58 }
  59
  60 int nud_state_a2n(unsigned *state, char *arg)
  61 {
  62         if (matches(arg, "permanent") == 0)
  63                 *state = NUD_PERMANENT;
  64         else if (matches(arg, "reachable") == 0)
  65                 *state = NUD_REACHABLE;
  66         else if (strcmp(arg, "noarp") == 0)
  67                 *state = NUD_NOARP;
  68         else if (strcmp(arg, "none") == 0)
  69                 *state = NUD_NONE;
  70         else if (strcmp(arg, "stale") == 0)
  71                 *state = NUD_STALE;
  72         else if (strcmp(arg, "incomplete") == 0)
  73                 *state = NUD_INCOMPLETE;
  74         else if (strcmp(arg, "delay") == 0)
  75                 *state = NUD_DELAY;
  76         else if (strcmp(arg, "probe") == 0)
  77                 *state = NUD_PROBE;
  78         else if (matches(arg, "failed") == 0)
  79                 *state = NUD_FAILED;
  80         else {
  81                 if (get_unsigned(state, arg, 0))
  82                         return -1;
  83                 if (*state>=0x100 || (*state&((*state)-1)))
  84                         return -1;
  85         }
  86         return 0;
  87 }
  88
  89 static int flush_update(void)
  90 {
  91         if (rtnl_send(&rth, filter.flushb, filter.flushp) < 0) {
  92                 perror("Failed to send flush request\n");
  93                 return -1;
  94         }
  95         filter.flushp = 0;
  96         return 0;
  97 }
  98
  99
 100 static int ipneigh_modify(int cmd, int flags, int argc, char **argv)
 101 {
 102         struct {
 103                 struct nlmsghdr         n;
 104                 struct ndmsg            ndm;
 105                 char                    buf[256];
 106         } req;
 107         char  *d = NULL;
 108         int dst_ok = 0;
 109         int lladdr_ok = 0;
 110         char * lla = NULL;
 111         inet_prefix dst;
 112
 113         memset(&req, 0, sizeof(req));
 114
 115         req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndmsg));
 116         req.n.nlmsg_flags = NLM_F_REQUEST|flags;
 117         req.n.nlmsg_type = cmd;
 118         req.ndm.ndm_family = preferred_family;
 119         req.ndm.ndm_state = NUD_PERMANENT;
 120
 121         while (argc > 0) {
 122                 if (matches(*argv, "lladdr") == 0) {
 123                         NEXT_ARG();
 124                         if (lladdr_ok)
 125                                 duparg("lladdr", *argv);
 126                         lla = *argv;
 127                         lladdr_ok = 1;
 128                 } else if (strcmp(*argv, "nud") == 0) {
 129                         unsigned state;
 130                         NEXT_ARG();
 131                         if (nud_state_a2n(&state, *argv))
 132                                 invarg("nud state is bad", *argv);
 133                         req.ndm.ndm_state = state;
 134                 } else if (matches(*argv, "proxy") == 0) {
 135                         NEXT_ARG();
 136                         if (matches(*argv, "help") == 0)
 137                                 usage();
 138                         if (dst_ok)
 139                                 duparg("address", *argv);
 140                         get_addr(&dst, *argv, preferred_family);
 141                         dst_ok = 1;
 142                         req.ndm.ndm_flags |= NTF_PROXY;
 143                 } else if (strcmp(*argv, "dev") == 0) {
 144                         NEXT_ARG();
 145                         d = *argv;
 146                 } else {
 147                         if (strcmp(*argv, "to") == 0) {
 148                                 NEXT_ARG();
 149                         }
 150                         if (matches(*argv, "help") == 0) {
 151                                 NEXT_ARG();
 152                         }
 153                         if (dst_ok)
 154                                 duparg2("to", *argv);
 155                         get_addr(&dst, *argv, preferred_family);
 156                         dst_ok = 1;
 157                 }
 158                 argc--; argv++;
 159         }
 160         if (d == NULL || !dst_ok || dst.family == AF_UNSPEC) {
 161                 fprintf(stderr, "Device and destination are required arguments.\n");
 162                 exit(-1);
 163         }
 164         req.ndm.ndm_family = dst.family;
 165         addattr_l(&req.n, sizeof(req), NDA_DST, &dst.data, dst.bytelen);
 166
 167         if (lla && strcmp(lla, "null")) {
 168                 char llabuf[20];
 169                 int l;
 170
 171                 l = ll_addr_a2n(llabuf, sizeof(llabuf), lla);
 172                 addattr_l(&req.n, sizeof(req), NDA_LLADDR, llabuf, l);
 173         }
 174
 175         ll_init_map(&rth);
 176
 177         if ((req.ndm.ndm_ifindex = ll_name_to_index(d)) == 0) {
 178                 fprintf(stderr, "Cannot find device \"%s\"\n", d);
 179                 return -1;
 180         }
 181
 182         if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
 183                 exit(2);
 184
 185         return 0;
 186 }
 187
 188
 189 int print_neigh(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
 190 {
 191         FILE *fp = (FILE*)arg;
 192         struct ndmsg *r = NLMSG_DATA(n);
 193         int len = n->nlmsg_len;
 194         struct rtattr * tb[NDA_MAX+1];
 195         char abuf[256];
 196
 197         if (n->nlmsg_type != RTM_NEWNEIGH && n->nlmsg_type != RTM_DELNEIGH) {
 198                 fprintf(stderr, "Not RTM_NEWNEIGH: %08x %08x %08x\n",
 199                         n->nlmsg_len, n->nlmsg_type, n->nlmsg_flags);
 200
 201                 return 0;
 202         }
 203         len -= NLMSG_LENGTH(sizeof(*r));
 204         if (len < 0) {
 205                 fprintf(stderr, "BUG: wrong nlmsg len %d\n", len);
 206                 return -1;
 207         }
 208
 209         if (filter.flushb && n->nlmsg_type != RTM_NEWNEIGH)
 210                 return 0;
 211
 212         if (filter.family && filter.family != r->ndm_family)
 213                 return 0;
 214         if (filter.index && filter.index != r->ndm_ifindex)
 215                 return 0;
 216         if (!(filter.state&r->ndm_state) &&
 217             (r->ndm_state || !(filter.state&0x100)) &&
 218              (r->ndm_family != AF_DECnet))
 219                 return 0;
 220
 221         parse_rtattr(tb, NDA_MAX, NDA_RTA(r), n->nlmsg_len - NLMSG_LENGTH(sizeof(*r)));
 222
 223         if (tb[NDA_DST]) {
 224                 if (filter.pfx.family) {
 225                         inet_prefix dst;
 226                         memset(&dst, 0, sizeof(dst));
 227                         dst.family = r->ndm_family;
 228                         memcpy(&dst.data, RTA_DATA(tb[NDA_DST]), RTA_PAYLOAD(tb[NDA_DST]));
 229                         if (inet_addr_match(&dst, &filter.pfx, filter.pfx.bitlen))
 230                                 return 0;
 231                 }
 232         }
 233         if (filter.unused_only && tb[NDA_CACHEINFO]) {
 234                 struct nda_cacheinfo *ci = RTA_DATA(tb[NDA_CACHEINFO]);
 235                 if (ci->ndm_refcnt)
 236                         return 0;
 237         }
 238
 239         if (filter.flushb) {
 240                 struct nlmsghdr *fn;
 241                 if (NLMSG_ALIGN(filter.flushp) + n->nlmsg_len > filter.flushe) {
 242                         if (flush_update())
 243                                 return -1;
 244                 }
 245                 fn = (struct nlmsghdr*)(filter.flushb + NLMSG_ALIGN(filter.flushp));
 246                 memcpy(fn, n, n->nlmsg_len);
 247                 fn->nlmsg_type = RTM_DELNEIGH;
 248                 fn->nlmsg_flags = NLM_F_REQUEST;
 249                 fn->nlmsg_seq = ++rth.seq;
 250                 filter.flushp = (((char*)fn) + n->nlmsg_len) - filter.flushb;
 251                 filter.flushed++;
 252                 if (show_stats < 2)
 253                         return 0;
 254         }
 255
 256         if (tb[NDA_DST]) {
 257                 fprintf(fp, "%s ",
 258                         format_host(r->ndm_family,
 259                                     RTA_PAYLOAD(tb[NDA_DST]),
 260                                     RTA_DATA(tb[NDA_DST]),
 261                                     abuf, sizeof(abuf)));
 262         }
 263         if (!filter.index && r->ndm_ifindex)
 264                 fprintf(fp, "dev %s ", ll_index_to_name(r->ndm_ifindex));
 265         if (tb[NDA_LLADDR]) {
 266                 SPRINT_BUF(b1);
 267                 fprintf(fp, "lladdr %s", ll_addr_n2a(RTA_DATA(tb[NDA_LLADDR]),
 268                                               RTA_PAYLOAD(tb[NDA_LLADDR]),
 269                                               ll_index_to_type(r->ndm_ifindex),
 270                                               b1, sizeof(b1)));
 271         }
 272         if (r->ndm_flags & NTF_ROUTER) {
 273                 fprintf(fp, " router");
 274         }
 275         if (tb[NDA_CACHEINFO] && show_stats) {
 276                 static int hz;
 277                 struct nda_cacheinfo *ci = RTA_DATA(tb[NDA_CACHEINFO]);
 278                 if (!hz)
 279                         hz = get_hz();
 280                 if (ci->ndm_refcnt)
 281                         printf(" ref %d", ci->ndm_refcnt);
 282                 fprintf(fp, " used %d/%d/%d", ci->ndm_used/hz,
 283                        ci->ndm_confirmed/hz, ci->ndm_updated/hz);
 284         }
 285
 286 #ifdef NDA_PROBES
 287         if (tb[NDA_PROBES] && show_stats) {
 288                 __u32 p = *(__u32 *) RTA_DATA(tb[NDA_PROBES]);
 289                 fprintf(fp, " probes %u", p);
 290         }
 291 #endif
 292
 293         if (r->ndm_state) {
 294                 int nud = r->ndm_state;
 295                 fprintf(fp, " ");
 296
 297 #define PRINT_FLAG(f) if (nud & NUD_##f) { \
 298         nud &= ~NUD_##f; fprintf(fp, #f "%s", nud ? "," : ""); }
 299                 PRINT_FLAG(INCOMPLETE);
 300                 PRINT_FLAG(REACHABLE);
 301                 PRINT_FLAG(STALE);
 302                 PRINT_FLAG(DELAY);
 303                 PRINT_FLAG(PROBE);
 304                 PRINT_FLAG(FAILED);
 305                 PRINT_FLAG(NOARP);
 306                 PRINT_FLAG(PERMANENT);
 307 #undef PRINT_FLAG
 308         }
 309         fprintf(fp, "\n");
 310
 311         fflush(fp);
 312         return 0;
 313 }
 314
 315 void ipneigh_reset_filter()
 316 {
 317         memset(&filter, 0, sizeof(filter));
 318         filter.state = ~0;
 319 }
 320
 321 int do_show_or_flush(int argc, char **argv, int flush)
 322 {
 323         char *filter_dev = NULL;
 324         int state_given = 0;
 325
 326         ipneigh_reset_filter();
 327
 328         if (!filter.family)
 329                 filter.family = preferred_family;
 330
 331         if (flush) {
 332                 if (argc <= 0) {
 333                         fprintf(stderr, "Flush requires arguments.\n");
 334                         return -1;
 335                 }
 336                 filter.state = ~(NUD_PERMANENT|NUD_NOARP);
 337         } else
 338                 filter.state = 0xFF & ~NUD_NOARP;
 339
 340         while (argc > 0) {
 341                 if (strcmp(*argv, "dev") == 0) {
 342                         NEXT_ARG();
 343                         if (filter_dev)
 344                                 duparg("dev", *argv);
 345                         filter_dev = *argv;
 346                 } else if (strcmp(*argv, "unused") == 0) {
 347                         filter.unused_only = 1;
 348                 } else if (strcmp(*argv, "nud") == 0) {
 349                         unsigned state;
 350                         NEXT_ARG();
 351                         if (!state_given) {
 352                                 state_given = 1;
 353                                 filter.state = 0;
 354                         }
 355                         if (nud_state_a2n(&state, *argv)) {
 356                                 if (strcmp(*argv, "all") != 0)
 357                                         invarg("nud state is bad", *argv);
 358                                 state = ~0;
 359                                 if (flush)
 360                                         state &= ~NUD_NOARP;
 361                         }
 362                         if (state == 0)
 363                                 state = 0x100;
 364                         filter.state |= state;
 365                 } else {
 366                         if (strcmp(*argv, "to") == 0) {
 367                                 NEXT_ARG();
 368                         }
 369                         if (matches(*argv, "help") == 0)
 370                                 usage();
 371                         get_prefix(&filter.pfx, *argv, filter.family);
 372                         if (filter.family == AF_UNSPEC)
 373                                 filter.family = filter.pfx.family;
 374                 }
 375                 argc--; argv++;
 376         }
 377
 378         ll_init_map(&rth);
 379
 380         if (filter_dev) {
 381                 if ((filter.index = ll_name_to_index(filter_dev)) == 0) {
 382                         fprintf(stderr, "Cannot find device \"%s\"\n", filter_dev);
 383                         return -1;
 384                 }
 385         }
 386
 387         if (flush) {
 388                 int round = 0;
 389                 char flushb[4096-512];
 390
 391                 filter.flushb = flushb;
 392                 filter.flushp = 0;
 393                 filter.flushe = sizeof(flushb);
 394                 filter.state &= ~NUD_FAILED;
 395
 396                 while (round < MAX_ROUNDS) {
 397                         if (rtnl_wilddump_request(&rth, filter.family, RTM_GETNEIGH) < 0) {
 398                                 perror("Cannot send dump request");
 399                                 exit(1);
 400                         }
 401                         filter.flushed = 0;
 402                         if (rtnl_dump_filter(&rth, print_neigh, stdout, NULL, NULL) < 0) {
 403                                 fprintf(stderr, "Flush terminated\n");
 404                                 exit(1);
 405                         }
 406                         if (filter.flushed == 0) {
 407                                 if (round == 0) {
 408                                         fprintf(stderr, "Nothing to flush.\n");
 409                                 } else if (show_stats)
 410                                         printf("*** Flush is complete after %d round%s ***\n", round, round>1?"s":"");
 411                                 fflush(stdout);
 412                                 return 0;
 413                         }
 414                         round++;
 415                         if (flush_update() < 0)
 416                                 exit(1);
 417                         if (show_stats) {
 418                                 printf("\n*** Round %d, deleting %d entries ***\n", round, filter.flushed);
 419                                 fflush(stdout);
 420                         }
 421                 }
 422                 printf("*** Flush not complete bailing out after %d rounds\n",
 423                         MAX_ROUNDS);
 424                 return 1;
 425         }
 426
 427         if (rtnl_wilddump_request(&rth, filter.family, RTM_GETNEIGH) < 0) {
 428                 perror("Cannot send dump request");
 429                 exit(1);
 430         }
 431
 432         if (rtnl_dump_filter(&rth, print_neigh, stdout, NULL, NULL) < 0) {
 433                 fprintf(stderr, "Dump terminated\n");
 434                 exit(1);
 435         }
 436
 437         return 0;
 438 }
 439
 440 int do_ipneigh(int argc, char **argv)
 441 {
 442         if (argc > 0) {
 443                 if (matches(*argv, "add") == 0)
 444                         return ipneigh_modify(RTM_NEWNEIGH, NLM_F_CREATE|NLM_F_EXCL, argc-1, argv+1);
 445                 if (matches(*argv, "change") == 0 ||
 446                     strcmp(*argv, "chg") == 0)
 447                         return ipneigh_modify(RTM_NEWNEIGH, NLM_F_REPLACE, argc-1, argv+1);
 448                 if (matches(*argv, "replace") == 0)
 449                         return ipneigh_modify(RTM_NEWNEIGH, NLM_F_CREATE|NLM_F_REPLACE, argc-1, argv+1);
 450                 if (matches(*argv, "delete") == 0)
 451                         return ipneigh_modify(RTM_DELNEIGH, 0, argc-1, argv+1);
 452                 if (matches(*argv, "get") == 0) {
 453                         fprintf(stderr, "Sorry, \"neigh get\" is not implemented :-(\n");
 454                         return -1;
 455                 }
 456                 if (matches(*argv, "show") == 0 ||
 457                     matches(*argv, "lst") == 0 ||
 458                     matches(*argv, "list") == 0)
 459                         return do_show_or_flush(argc-1, argv+1, 0);
 460                 if (matches(*argv, "flush") == 0)
 461                         return do_show_or_flush(argc-1, argv+1, 1);
 462                 if (matches(*argv, "help") == 0)
 463                         usage();
 464         } else
 465                 return do_show_or_flush(0, NULL, 0);
 466
 467         fprintf(stderr, "Command \"%s\" is unknown, try \"ip neigh help\".\n", *argv);
 468         exit(-1);
 469 }