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
  35 static struct
  36 {
  37         int family;
  38         int index;
  39         int state;
  40         int unused_only;
  41         inet_prefix pfx;
  42         int flushed;
  43         char *flushb;
  44         int flushp;
  45         int flushe;
  46         struct rtnl_handle *rth;
  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(filter.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 rtnl_handle rth;
 103         struct {
 104                 struct nlmsghdr         n;
 105                 struct ndmsg            ndm;
 106                 char                    buf[256];
 107         } req;
 108         char  *d = NULL;
 109         int dst_ok = 0;
 110         int lladdr_ok = 0;
 111         char * lla = NULL;
 112         inet_prefix dst;
 113
 114         memset(&req, 0, sizeof(req));
 115
 116         req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndmsg));
 117         req.n.nlmsg_flags = NLM_F_REQUEST|flags;
 118         req.n.nlmsg_type = cmd;
 119         req.ndm.ndm_family = preferred_family;
 120         req.ndm.ndm_state = NUD_PERMANENT;
 121
 122         while (argc > 0) {
 123                 if (matches(*argv, "lladdr") == 0) {
 124                         NEXT_ARG();
 125                         if (lladdr_ok)
 126                                 duparg("lladdr", *argv);
 127                         lla = *argv;
 128                         lladdr_ok = 1;
 129                 } else if (strcmp(*argv, "nud") == 0) {
 130                         unsigned state;
 131                         NEXT_ARG();
 132                         if (nud_state_a2n(&state, *argv))
 133                                 invarg("nud state is bad", *argv);
 134                         req.ndm.ndm_state = state;
 135                 } else if (matches(*argv, "proxy") == 0) {
 136                         NEXT_ARG();
 137                         if (matches(*argv, "help") == 0)
 138                                 usage();
 139                         if (dst_ok)
 140                                 duparg("address", *argv);
 141                         get_addr(&dst, *argv, preferred_family);
 142                         dst_ok = 1;
 143                         req.ndm.ndm_flags |= NTF_PROXY;
 144                 } else if (strcmp(*argv, "dev") == 0) {
 145                         NEXT_ARG();
 146                         d = *argv;
 147                 } else {
 148                         if (strcmp(*argv, "to") == 0) {
 149                                 NEXT_ARG();
 150                         }
 151                         if (matches(*argv, "help") == 0) {
 152                                 NEXT_ARG();
 153                         }
 154                         if (dst_ok)
 155                                 duparg2("to", *argv);
 156                         get_addr(&dst, *argv, preferred_family);
 157                         dst_ok = 1;
 158                 }
 159                 argc--; argv++;
 160         }
 161         if (d == NULL || !dst_ok || dst.family == AF_UNSPEC) {
 162                 fprintf(stderr, "Device and destination are required arguments.\n");
 163                 exit(-1);
 164         }
 165         req.ndm.ndm_family = dst.family;
 166         addattr_l(&req.n, sizeof(req), NDA_DST, &dst.data, dst.bytelen);
 167
 168         if (lla && strcmp(lla, "null")) {
 169                 __u8 llabuf[16];
 170                 int l;
 171
 172                 l = ll_addr_a2n(llabuf, sizeof(llabuf), lla);
 173                 addattr_l(&req.n, sizeof(req), NDA_LLADDR, llabuf, l);
 174         }
 175
 176         if (rtnl_open(&rth, 0) < 0)
 177                 exit(1);
 178
 179         ll_init_map(&rth);
 180
 181         if ((req.ndm.ndm_ifindex = ll_name_to_index(d)) == 0) {
 182                 fprintf(stderr, "Cannot find device \"%s\"\n", d);
 183                 return -1;
 184         }
 185
 186         if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
 187                 exit(2);
 188
 189         exit(0);
 190 }
 191
 192
 193 int print_neigh(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
 194 {
 195         FILE *fp = (FILE*)arg;
 196         struct ndmsg *r = NLMSG_DATA(n);
 197         int len = n->nlmsg_len;
 198         struct rtattr * tb[NDA_MAX+1];
 199         char abuf[256];
 200
 201         if (n->nlmsg_type != RTM_NEWNEIGH && n->nlmsg_type != RTM_DELNEIGH) {
 202                 fprintf(stderr, "Not RTM_NEWNEIGH: %08x %08x %08x\n",
 203                         n->nlmsg_len, n->nlmsg_type, n->nlmsg_flags);
 204
 205                 return 0;
 206         }
 207         len -= NLMSG_LENGTH(sizeof(*r));
 208         if (len < 0) {
 209                 fprintf(stderr, "BUG: wrong nlmsg len %d\n", len);
 210                 return -1;
 211         }
 212
 213         if (filter.flushb && n->nlmsg_type != RTM_NEWNEIGH)
 214                 return 0;
 215
 216         if (filter.family && filter.family != r->ndm_family)
 217                 return 0;
 218         if (filter.index && filter.index != r->ndm_ifindex)
 219                 return 0;
 220         if (!(filter.state&r->ndm_state) &&
 221             (r->ndm_state || !(filter.state&0x100)) &&
 222              (r->ndm_family != AF_DECnet))
 223                 return 0;
 224
 225         parse_rtattr(tb, NDA_MAX, NDA_RTA(r), n->nlmsg_len - NLMSG_LENGTH(sizeof(*r)));
 226
 227         if (tb[NDA_DST]) {
 228                 if (filter.pfx.family) {
 229                         inet_prefix dst;
 230                         memset(&dst, 0, sizeof(dst));
 231                         dst.family = r->ndm_family;
 232                         memcpy(&dst.data, RTA_DATA(tb[NDA_DST]), RTA_PAYLOAD(tb[NDA_DST]));
 233                         if (inet_addr_match(&dst, &filter.pfx, filter.pfx.bitlen))
 234                                 return 0;
 235                 }
 236         }
 237         if (filter.unused_only && tb[NDA_CACHEINFO]) {
 238                 struct nda_cacheinfo *ci = RTA_DATA(tb[NDA_CACHEINFO]);
 239                 if (ci->ndm_refcnt)
 240                         return 0;
 241         }
 242
 243         if (filter.flushb) {
 244                 struct nlmsghdr *fn;
 245                 if (NLMSG_ALIGN(filter.flushp) + n->nlmsg_len > filter.flushe) {
 246                         if (flush_update())
 247                                 return -1;
 248                 }
 249                 fn = (struct nlmsghdr*)(filter.flushb + NLMSG_ALIGN(filter.flushp));
 250                 memcpy(fn, n, n->nlmsg_len);
 251                 fn->nlmsg_type = RTM_DELNEIGH;
 252                 fn->nlmsg_flags = NLM_F_REQUEST;
 253                 fn->nlmsg_seq = ++filter.rth->seq;
 254                 filter.flushp = (((char*)fn) + n->nlmsg_len) - filter.flushb;
 255                 filter.flushed++;
 256                 if (show_stats < 2)
 257                         return 0;
 258         }
 259
 260         if (tb[NDA_DST]) {
 261                 fprintf(fp, "%s ",
 262                         format_host(r->ndm_family,
 263                                     RTA_PAYLOAD(tb[NDA_DST]),
 264                                     RTA_DATA(tb[NDA_DST]),
 265                                     abuf, sizeof(abuf)));
 266         }
 267         if (!filter.index && r->ndm_ifindex)
 268                 fprintf(fp, "dev %s ", ll_index_to_name(r->ndm_ifindex));
 269         if (tb[NDA_LLADDR]) {
 270                 SPRINT_BUF(b1);
 271                 fprintf(fp, "lladdr %s", ll_addr_n2a(RTA_DATA(tb[NDA_LLADDR]),
 272                                               RTA_PAYLOAD(tb[NDA_LLADDR]),
 273                                               ll_index_to_type(r->ndm_ifindex),
 274                                               b1, sizeof(b1)));
 275         }
 276         if (r->ndm_flags & NTF_ROUTER) {
 277                 fprintf(fp, " router");
 278         }
 279         if (tb[NDA_CACHEINFO] && show_stats) {
 280                 static int hz;
 281                 struct nda_cacheinfo *ci = RTA_DATA(tb[NDA_CACHEINFO]);
 282                 if (!hz)
 283                         hz = get_hz();
 284                 if (ci->ndm_refcnt)
 285                         printf(" ref %d", ci->ndm_refcnt);
 286                 fprintf(fp, " used %d/%d/%d", ci->ndm_used/hz,
 287                        ci->ndm_confirmed/hz, ci->ndm_updated/hz);
 288         }
 289
 290 #ifdef NDA_PROBES
 291         if (tb[NDA_PROBES] && show_stats) {
 292                 __u32 p = *(__u32 *) RTA_DATA(tb[NDA_PROBES]);
 293                 fprintf(fp, " probes %u", p);
 294         }
 295 #endif
 296
 297         if (r->ndm_state) {
 298                 int nud = r->ndm_state;
 299                 fprintf(fp, " ");
 300
 301 #define PRINT_FLAG(f) if (nud & NUD_##f) { \
 302         nud &= ~NUD_##f; fprintf(fp, #f "%s", nud ? "," : ""); }
 303                 PRINT_FLAG(INCOMPLETE);
 304                 PRINT_FLAG(REACHABLE);
 305                 PRINT_FLAG(STALE);
 306                 PRINT_FLAG(DELAY);
 307                 PRINT_FLAG(PROBE);
 308                 PRINT_FLAG(FAILED);
 309                 PRINT_FLAG(NOARP);
 310                 PRINT_FLAG(PERMANENT);
 311 #undef PRINT_FLAG
 312         }
 313         fprintf(fp, "\n");
 314
 315         fflush(fp);
 316         return 0;
 317 }
 318
 319 void ipneigh_reset_filter()
 320 {
 321         memset(&filter, 0, sizeof(filter));
 322         filter.state = ~0;
 323 }
 324
 325 int do_show_or_flush(int argc, char **argv, int flush)
 326 {
 327         char *filter_dev = NULL;
 328         struct rtnl_handle rth;
 329         int state_given = 0;
 330
 331         ipneigh_reset_filter();
 332
 333         if (!filter.family)
 334                 filter.family = preferred_family;
 335
 336         if (flush) {
 337                 if (argc <= 0) {
 338                         fprintf(stderr, "Flush requires arguments.\n");
 339                         return -1;
 340                 }
 341                 filter.state = ~(NUD_PERMANENT|NUD_NOARP);
 342         } else
 343                 filter.state = 0xFF & ~NUD_NOARP;
 344
 345         while (argc > 0) {
 346                 if (strcmp(*argv, "dev") == 0) {
 347                         NEXT_ARG();
 348                         if (filter_dev)
 349                                 duparg("dev", *argv);
 350                         filter_dev = *argv;
 351                 } else if (strcmp(*argv, "unused") == 0) {
 352                         filter.unused_only = 1;
 353                 } else if (strcmp(*argv, "nud") == 0) {
 354                         unsigned state;
 355                         NEXT_ARG();
 356                         if (!state_given) {
 357                                 state_given = 1;
 358                                 filter.state = 0;
 359                         }
 360                         if (nud_state_a2n(&state, *argv)) {
 361                                 if (strcmp(*argv, "all") != 0)
 362                                         invarg("nud state is bad", *argv);
 363                                 state = ~0;
 364                                 if (flush)
 365                                         state &= ~NUD_NOARP;
 366                         }
 367                         if (state == 0)
 368                                 state = 0x100;
 369                         filter.state |= state;
 370                 } else {
 371                         if (strcmp(*argv, "to") == 0) {
 372                                 NEXT_ARG();
 373                         }
 374                         if (matches(*argv, "help") == 0)
 375                                 usage();
 376                         get_prefix(&filter.pfx, *argv, filter.family);
 377                         if (filter.family == AF_UNSPEC)
 378                                 filter.family = filter.pfx.family;
 379                 }
 380                 argc--; argv++;
 381         }
 382
 383         if (rtnl_open(&rth, 0) < 0)
 384                 exit(1);
 385
 386         ll_init_map(&rth);
 387
 388         if (filter_dev) {
 389                 if ((filter.index = ll_name_to_index(filter_dev)) == 0) {
 390                         fprintf(stderr, "Cannot find device \"%s\"\n", filter_dev);
 391                         return -1;
 392                 }
 393         }
 394
 395         if (flush) {
 396                 int round = 0;
 397                 char flushb[4096-512];
 398
 399                 filter.flushb = flushb;
 400                 filter.flushp = 0;
 401                 filter.flushe = sizeof(flushb);
 402                 filter.rth = &rth;
 403                 filter.state &= ~NUD_FAILED;
 404
 405                 for (;;) {
 406                         if (rtnl_wilddump_request(&rth, filter.family, RTM_GETNEIGH) < 0) {
 407                                 perror("Cannot send dump request");
 408                                 exit(1);
 409                         }
 410                         filter.flushed = 0;
 411                         if (rtnl_dump_filter(&rth, print_neigh, stdout, NULL, NULL) < 0) {
 412                                 fprintf(stderr, "Flush terminated\n");
 413                                 exit(1);
 414                         }
 415                         if (filter.flushed == 0) {
 416                                 if (round == 0) {
 417                                         fprintf(stderr, "Nothing to flush.\n");
 418                                 } else if (show_stats)
 419                                         printf("*** Flush is complete after %d round%s ***\n", round, round>1?"s":"");
 420                                 fflush(stdout);
 421                                 return 0;
 422                         }
 423                         round++;
 424                         if (flush_update() < 0)
 425                                 exit(1);
 426                         if (show_stats) {
 427                                 printf("\n*** Round %d, deleting %d entries ***\n", round, filter.flushed);
 428                                 fflush(stdout);
 429                         }
 430                 }
 431         }
 432
 433         if (rtnl_wilddump_request(&rth, filter.family, RTM_GETNEIGH) < 0) {
 434                 perror("Cannot send dump request");
 435                 exit(1);
 436         }
 437
 438         if (rtnl_dump_filter(&rth, print_neigh, stdout, NULL, NULL) < 0) {
 439                 fprintf(stderr, "Dump terminated\n");
 440                 exit(1);
 441         }
 442
 443         return 0;
 444 }
 445
 446 int do_ipneigh(int argc, char **argv)
 447 {
 448         if (argc > 0) {
 449                 if (matches(*argv, "add") == 0)
 450                         return ipneigh_modify(RTM_NEWNEIGH, NLM_F_CREATE|NLM_F_EXCL, argc-1, argv+1);
 451                 if (matches(*argv, "change") == 0 ||
 452                     strcmp(*argv, "chg") == 0)
 453                         return ipneigh_modify(RTM_NEWNEIGH, NLM_F_REPLACE, argc-1, argv+1);
 454                 if (matches(*argv, "replace") == 0)
 455                         return ipneigh_modify(RTM_NEWNEIGH, NLM_F_CREATE|NLM_F_REPLACE, argc-1, argv+1);
 456                 if (matches(*argv, "delete") == 0)
 457                         return ipneigh_modify(RTM_DELNEIGH, 0, argc-1, argv+1);
 458                 if (matches(*argv, "get") == 0) {
 459                         fprintf(stderr, "Sorry, \"neigh get\" is not implemented :-(\n");
 460                         return -1;
 461                 }
 462                 if (matches(*argv, "show") == 0 ||
 463                     matches(*argv, "lst") == 0 ||
 464                     matches(*argv, "list") == 0)
 465                         return do_show_or_flush(argc-1, argv+1, 0);
 466                 if (matches(*argv, "flush") == 0)
 467                         return do_show_or_flush(argc-1, argv+1, 1);
 468                 if (matches(*argv, "help") == 0)
 469                         usage();
 470         } else
 471                 return do_show_or_flush(0, NULL, 0);
 472
 473         fprintf(stderr, "Command \"%s\" is unknown, try \"ip neigh help\".\n", *argv);
 474         exit(-1);
 475 }