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         int master;
  43 } filter;
  44
  45 static void usage(void) __attribute__((noreturn));
  46
  47 static void usage(void)
  48 {
  49         fprintf(stderr, "Usage: ip neigh { add | del | change | replace } { ADDR [ lladdr LLADDR ]\n"
  50                         "          [ nud { permanent | noarp | stale | reachable } ]\n"
  51                         "          | proxy ADDR } [ dev DEV ]\n");
  52         fprintf(stderr, "       ip neigh {show|flush} [ to PREFIX ] [ dev DEV ] [ nud STATE ]\n");
  53         exit(-1);
  54 }
  55
  56 static int nud_state_a2n(unsigned *state, const char *arg)
  57 {
  58         if (matches(arg, "permanent") == 0)
  59                 *state = NUD_PERMANENT;
  60         else if (matches(arg, "reachable") == 0)
  61                 *state = NUD_REACHABLE;
  62         else if (strcmp(arg, "noarp") == 0)
  63                 *state = NUD_NOARP;
  64         else if (strcmp(arg, "none") == 0)
  65                 *state = NUD_NONE;
  66         else if (strcmp(arg, "stale") == 0)
  67                 *state = NUD_STALE;
  68         else if (strcmp(arg, "incomplete") == 0)
  69                 *state = NUD_INCOMPLETE;
  70         else if (strcmp(arg, "delay") == 0)
  71                 *state = NUD_DELAY;
  72         else if (strcmp(arg, "probe") == 0)
  73                 *state = NUD_PROBE;
  74         else if (matches(arg, "failed") == 0)
  75                 *state = NUD_FAILED;
  76         else {
  77                 if (get_unsigned(state, arg, 0))
  78                         return -1;
  79                 if (*state>=0x100 || (*state&((*state)-1)))
  80                         return -1;
  81         }
  82         return 0;
  83 }
  84
  85 static int flush_update(void)
  86 {
  87         if (rtnl_send_check(&rth, filter.flushb, filter.flushp) < 0) {
  88                 perror("Failed to send flush request");
  89                 return -1;
  90         }
  91         filter.flushp = 0;
  92         return 0;
  93 }
  94
  95
  96 static int ipneigh_modify(int cmd, int flags, int argc, char **argv)
  97 {
  98         struct {
  99                 struct nlmsghdr n;
 100                 struct ndmsg            ndm;
 101                 char                    buf[256];
 102         } req;
 103         char  *d = NULL;
 104         int dst_ok = 0;
 105         int lladdr_ok = 0;
 106         char * lla = NULL;
 107         inet_prefix dst;
 108
 109         memset(&req, 0, sizeof(req));
 110
 111         req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndmsg));
 112         req.n.nlmsg_flags = NLM_F_REQUEST|flags;
 113         req.n.nlmsg_type = cmd;
 114         req.ndm.ndm_family = preferred_family;
 115         req.ndm.ndm_state = NUD_PERMANENT;
 116
 117         while (argc > 0) {
 118                 if (matches(*argv, "lladdr") == 0) {
 119                         NEXT_ARG();
 120                         if (lladdr_ok)
 121                                 duparg("lladdr", *argv);
 122                         lla = *argv;
 123                         lladdr_ok = 1;
 124                 } else if (strcmp(*argv, "nud") == 0) {
 125                         unsigned state;
 126                         NEXT_ARG();
 127                         if (nud_state_a2n(&state, *argv))
 128                                 invarg("nud state is bad", *argv);
 129                         req.ndm.ndm_state = state;
 130                 } else if (matches(*argv, "proxy") == 0) {
 131                         NEXT_ARG();
 132                         if (matches(*argv, "help") == 0)
 133                                 usage();
 134                         if (dst_ok)
 135                                 duparg("address", *argv);
 136                         get_addr(&dst, *argv, preferred_family);
 137                         dst_ok = 1;
 138                         req.ndm.ndm_flags |= NTF_PROXY;
 139                 } else if (strcmp(*argv, "dev") == 0) {
 140                         NEXT_ARG();
 141                         d = *argv;
 142                 } else {
 143                         if (strcmp(*argv, "to") == 0) {
 144                                 NEXT_ARG();
 145                         }
 146                         if (matches(*argv, "help") == 0) {
 147                                 NEXT_ARG();
 148                         }
 149                         if (dst_ok)
 150                                 duparg2("to", *argv);
 151                         get_addr(&dst, *argv, preferred_family);
 152                         dst_ok = 1;
 153                 }
 154                 argc--; argv++;
 155         }
 156         if (d == NULL || !dst_ok || dst.family == AF_UNSPEC) {
 157                 fprintf(stderr, "Device and destination are required arguments.\n");
 158                 exit(-1);
 159         }
 160         req.ndm.ndm_family = dst.family;
 161         if (addattr_l(&req.n, sizeof(req), NDA_DST, &dst.data, dst.bytelen) < 0)
 162                 return -1;
 163
 164         if (lla && strcmp(lla, "null")) {
 165                 char llabuf[20];
 166                 int l;
 167
 168                 l = ll_addr_a2n(llabuf, sizeof(llabuf), lla);
 169                 if (l < 0)
 170                         return -1;
 171
 172                 if (addattr_l(&req.n, sizeof(req), NDA_LLADDR, llabuf, l) < 0)
 173                         return -1;
 174         }
 175
 176         ll_init_map(&rth);
 177
 178         if ((req.ndm.ndm_ifindex = ll_name_to_index(d)) == 0) {
 179                 fprintf(stderr, "Cannot find device \"%s\"\n", d);
 180                 return -1;
 181         }
 182
 183         if (rtnl_talk(&rth, &req.n, NULL, 0) < 0)
 184                 exit(2);
 185
 186         return 0;
 187 }
 188
 189
 190 int print_neigh(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
 191 {
 192         FILE *fp = (FILE*)arg;
 193         struct ndmsg *r = NLMSG_DATA(n);
 194         int len = n->nlmsg_len;
 195         struct rtattr * tb[NDA_MAX+1];
 196         char abuf[256];
 197         static int logit = 1;
 198
 199         if (n->nlmsg_type != RTM_NEWNEIGH && n->nlmsg_type != RTM_DELNEIGH &&
 200             n->nlmsg_type != RTM_GETNEIGH) {
 201                 fprintf(stderr, "Not RTM_NEWNEIGH: %08x %08x %08x\n",
 202                         n->nlmsg_len, n->nlmsg_type, n->nlmsg_flags);
 203
 204                 return 0;
 205         }
 206         len -= NLMSG_LENGTH(sizeof(*r));
 207         if (len < 0) {
 208                 fprintf(stderr, "BUG: wrong nlmsg len %d\n", len);
 209                 return -1;
 210         }
 211
 212         if (filter.flushb && n->nlmsg_type != RTM_NEWNEIGH)
 213                 return 0;
 214
 215         if (filter.family && filter.family != r->ndm_family)
 216                 return 0;
 217         if (filter.index && filter.index != r->ndm_ifindex)
 218                 return 0;
 219         if (!(filter.state&r->ndm_state) &&
 220             !(r->ndm_flags & NTF_PROXY) &&
 221             (r->ndm_state || !(filter.state&0x100)) &&
 222              (r->ndm_family != AF_DECnet))
 223                 return 0;
 224
 225         if (filter.master && !(n->nlmsg_flags & NLM_F_DUMP_FILTERED)) {
 226                 if (logit) {
 227                         logit = 0;
 228                         fprintf(fp,
 229                                 "\nWARNING: Kernel does not support filtering by master device\n\n");
 230                 }
 231         }
 232
 233         parse_rtattr(tb, NDA_MAX, NDA_RTA(r), n->nlmsg_len - NLMSG_LENGTH(sizeof(*r)));
 234
 235         if (tb[NDA_DST]) {
 236                 if (filter.pfx.family) {
 237                         inet_prefix dst;
 238                         memset(&dst, 0, sizeof(dst));
 239                         dst.family = r->ndm_family;
 240                         memcpy(&dst.data, RTA_DATA(tb[NDA_DST]), RTA_PAYLOAD(tb[NDA_DST]));
 241                         if (inet_addr_match(&dst, &filter.pfx, filter.pfx.bitlen))
 242                                 return 0;
 243                 }
 244         }
 245         if (filter.unused_only && tb[NDA_CACHEINFO]) {
 246                 struct nda_cacheinfo *ci = RTA_DATA(tb[NDA_CACHEINFO]);
 247                 if (ci->ndm_refcnt)
 248                         return 0;
 249         }
 250
 251         if (filter.flushb) {
 252                 struct nlmsghdr *fn;
 253                 if (NLMSG_ALIGN(filter.flushp) + n->nlmsg_len > filter.flushe) {
 254                         if (flush_update())
 255                                 return -1;
 256                 }
 257                 fn = (struct nlmsghdr*)(filter.flushb + NLMSG_ALIGN(filter.flushp));
 258                 memcpy(fn, n, n->nlmsg_len);
 259                 fn->nlmsg_type = RTM_DELNEIGH;
 260                 fn->nlmsg_flags = NLM_F_REQUEST;
 261                 fn->nlmsg_seq = ++rth.seq;
 262                 filter.flushp = (((char*)fn) + n->nlmsg_len) - filter.flushb;
 263                 filter.flushed++;
 264                 if (show_stats < 2)
 265                         return 0;
 266         }
 267
 268         if (n->nlmsg_type == RTM_DELNEIGH)
 269                 fprintf(fp, "Deleted ");
 270         else if (n->nlmsg_type == RTM_GETNEIGH)
 271                 fprintf(fp, "miss ");
 272         if (tb[NDA_DST]) {
 273                 fprintf(fp, "%s ",
 274                         format_host(r->ndm_family,
 275                                     RTA_PAYLOAD(tb[NDA_DST]),
 276                                     RTA_DATA(tb[NDA_DST]),
 277                                     abuf, sizeof(abuf)));
 278         }
 279         if (!filter.index && r->ndm_ifindex)
 280                 fprintf(fp, "dev %s ", ll_index_to_name(r->ndm_ifindex));
 281         if (tb[NDA_LLADDR]) {
 282                 SPRINT_BUF(b1);
 283                 fprintf(fp, "lladdr %s", ll_addr_n2a(RTA_DATA(tb[NDA_LLADDR]),
 284                                               RTA_PAYLOAD(tb[NDA_LLADDR]),
 285                                               ll_index_to_type(r->ndm_ifindex),
 286                                               b1, sizeof(b1)));
 287         }
 288         if (r->ndm_flags & NTF_ROUTER) {
 289                 fprintf(fp, " router");
 290         }
 291         if (r->ndm_flags & NTF_PROXY) {
 292                 fprintf(fp, " proxy");
 293         }
 294         if (tb[NDA_CACHEINFO] && show_stats) {
 295                 struct nda_cacheinfo *ci = RTA_DATA(tb[NDA_CACHEINFO]);
 296                 int hz = get_user_hz();
 297
 298                 if (ci->ndm_refcnt)
 299                         printf(" ref %d", ci->ndm_refcnt);
 300                 fprintf(fp, " used %d/%d/%d", ci->ndm_used/hz,
 301                        ci->ndm_confirmed/hz, ci->ndm_updated/hz);
 302         }
 303
 304         if (tb[NDA_PROBES] && show_stats) {
 305                 __u32 p = rta_getattr_u32(tb[NDA_PROBES]);
 306                 fprintf(fp, " probes %u", p);
 307         }
 308
 309         if (r->ndm_state) {
 310                 int nud = r->ndm_state;
 311                 fprintf(fp, " ");
 312
 313 #define PRINT_FLAG(f) if (nud & NUD_##f) { \
 314         nud &= ~NUD_##f; fprintf(fp, #f "%s", nud ? "," : ""); }
 315                 PRINT_FLAG(INCOMPLETE);
 316                 PRINT_FLAG(REACHABLE);
 317                 PRINT_FLAG(STALE);
 318                 PRINT_FLAG(DELAY);
 319                 PRINT_FLAG(PROBE);
 320                 PRINT_FLAG(FAILED);
 321                 PRINT_FLAG(NOARP);
 322                 PRINT_FLAG(PERMANENT);
 323 #undef PRINT_FLAG
 324         }
 325         fprintf(fp, "\n");
 326
 327         fflush(fp);
 328         return 0;
 329 }
 330
 331 void ipneigh_reset_filter(int ifindex)
 332 {
 333         memset(&filter, 0, sizeof(filter));
 334         filter.state = ~0;
 335         filter.index = ifindex;
 336 }
 337
 338 static int do_show_or_flush(int argc, char **argv, int flush)
 339 {
 340         struct {
 341                 struct nlmsghdr n;
 342                 struct ndmsg            ndm;
 343                 char                    buf[256];
 344         } req;
 345         char *filter_dev = NULL;
 346         int state_given = 0;
 347
 348         memset(&req, 0, sizeof(req));
 349
 350         req.n.nlmsg_type = RTM_GETNEIGH;
 351         req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndmsg));
 352
 353         ipneigh_reset_filter(0);
 354
 355         if (!filter.family)
 356                 filter.family = preferred_family;
 357
 358         if (flush) {
 359                 if (argc <= 0) {
 360                         fprintf(stderr, "Flush requires arguments.\n");
 361                         return -1;
 362                 }
 363                 filter.state = ~(NUD_PERMANENT|NUD_NOARP);
 364         } else
 365                 filter.state = 0xFF & ~NUD_NOARP;
 366
 367         while (argc > 0) {
 368                 if (strcmp(*argv, "dev") == 0) {
 369                         NEXT_ARG();
 370                         if (filter_dev)
 371                                 duparg("dev", *argv);
 372                         filter_dev = *argv;
 373                 } else if (strcmp(*argv, "master") == 0) {
 374                         int ifindex;
 375                         NEXT_ARG();
 376                         ifindex = ll_name_to_index(*argv);
 377                         if (!ifindex)
 378                                 invarg("Device does not exist\n", *argv);
 379                         addattr32(&req.n, sizeof(req), NDA_MASTER, ifindex);
 380                         filter.master = ifindex;
 381                 } else if (strcmp(*argv, "unused") == 0) {
 382                         filter.unused_only = 1;
 383                 } else if (strcmp(*argv, "nud") == 0) {
 384                         unsigned state;
 385                         NEXT_ARG();
 386                         if (!state_given) {
 387                                 state_given = 1;
 388                                 filter.state = 0;
 389                         }
 390                         if (nud_state_a2n(&state, *argv)) {
 391                                 if (strcmp(*argv, "all") != 0)
 392                                         invarg("nud state is bad", *argv);
 393                                 state = ~0;
 394                                 if (flush)
 395                                         state &= ~NUD_NOARP;
 396                         }
 397                         if (state == 0)
 398                                 state = 0x100;
 399                         filter.state |= state;
 400                 } else if (strcmp(*argv, "proxy") == 0)
 401                         req.ndm.ndm_flags = NTF_PROXY;
 402                 else {
 403                         if (strcmp(*argv, "to") == 0) {
 404                                 NEXT_ARG();
 405                         }
 406                         if (matches(*argv, "help") == 0)
 407                                 usage();
 408                         get_prefix(&filter.pfx, *argv, filter.family);
 409                         if (filter.family == AF_UNSPEC)
 410                                 filter.family = filter.pfx.family;
 411                 }
 412                 argc--; argv++;
 413         }
 414
 415         ll_init_map(&rth);
 416
 417         if (filter_dev) {
 418                 if ((filter.index = ll_name_to_index(filter_dev)) == 0) {
 419                         fprintf(stderr, "Cannot find device \"%s\"\n", filter_dev);
 420                         return -1;
 421                 }
 422                 addattr32(&req.n, sizeof(req), NDA_IFINDEX, filter.index);
 423         }
 424
 425         if (flush) {
 426                 int round = 0;
 427                 char flushb[4096-512];
 428
 429                 filter.flushb = flushb;
 430                 filter.flushp = 0;
 431                 filter.flushe = sizeof(flushb);
 432                 filter.state &= ~NUD_FAILED;
 433
 434                 while (round < MAX_ROUNDS) {
 435                         if (rtnl_wilddump_request(&rth, filter.family, RTM_GETNEIGH) < 0) {
 436                                 perror("Cannot send dump request");
 437                                 exit(1);
 438                         }
 439                         filter.flushed = 0;
 440                         if (rtnl_dump_filter(&rth, print_neigh, stdout) < 0) {
 441                                 fprintf(stderr, "Flush terminated\n");
 442                                 exit(1);
 443                         }
 444                         if (filter.flushed == 0) {
 445                                 if (show_stats) {
 446                                         if (round == 0)
 447                                                 printf("Nothing to flush.\n");
 448                                         else
 449                                                 printf("*** Flush is complete after %d round%s ***\n", round, round>1?"s":"");
 450                                 }
 451                                 fflush(stdout);
 452                                 return 0;
 453                         }
 454                         round++;
 455                         if (flush_update() < 0)
 456                                 exit(1);
 457                         if (show_stats) {
 458                                 printf("\n*** Round %d, deleting %d entries ***\n", round, filter.flushed);
 459                                 fflush(stdout);
 460                         }
 461                 }
 462                 printf("*** Flush not complete bailing out after %d rounds\n",
 463                         MAX_ROUNDS);
 464                 return 1;
 465         }
 466
 467         req.ndm.ndm_family = filter.family;
 468
 469         if (rtnl_dump_request_n(&rth, &req.n) < 0) {
 470                 perror("Cannot send dump request");
 471                 exit(1);
 472         }
 473
 474         if (rtnl_dump_filter(&rth, print_neigh, stdout) < 0) {
 475                 fprintf(stderr, "Dump terminated\n");
 476                 exit(1);
 477         }
 478
 479         return 0;
 480 }
 481
 482 int do_ipneigh(int argc, char **argv)
 483 {
 484         if (argc > 0) {
 485                 if (matches(*argv, "add") == 0)
 486                         return ipneigh_modify(RTM_NEWNEIGH, NLM_F_CREATE|NLM_F_EXCL, argc-1, argv+1);
 487                 if (matches(*argv, "change") == 0 ||
 488                     strcmp(*argv, "chg") == 0)
 489                         return ipneigh_modify(RTM_NEWNEIGH, NLM_F_REPLACE, argc-1, argv+1);
 490                 if (matches(*argv, "replace") == 0)
 491                         return ipneigh_modify(RTM_NEWNEIGH, NLM_F_CREATE|NLM_F_REPLACE, argc-1, argv+1);
 492                 if (matches(*argv, "delete") == 0)
 493                         return ipneigh_modify(RTM_DELNEIGH, 0, argc-1, argv+1);
 494                 if (matches(*argv, "get") == 0) {
 495                         fprintf(stderr, "Sorry, \"neigh get\" is not implemented :-(\n");
 496                         return -1;
 497                 }
 498                 if (matches(*argv, "show") == 0 ||
 499                     matches(*argv, "lst") == 0 ||
 500                     matches(*argv, "list") == 0)
 501                         return do_show_or_flush(argc-1, argv+1, 0);
 502                 if (matches(*argv, "flush") == 0)
 503                         return do_show_or_flush(argc-1, argv+1, 1);
 504                 if (matches(*argv, "help") == 0)
 505                         usage();
 506         } else
 507                 return do_show_or_flush(0, NULL, 0);
 508
 509         fprintf(stderr, "Command \"%s\" is unknown, try \"ip neigh help\".\n", *argv);
 510         exit(-1);
 511 }