networking/libiproute/ipneigh.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   4  *
   5  * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
   6  *
   7  * Ported to Busybox by:  Curt Brune <curt@cumulusnetworks.com>
   8  */
   9
  10 #include "ip_common.h"  /* #include "libbb.h" is inside */
  11 #include "common_bufsiz.h"
  12 #include "rt_names.h"
  13 #include "utils.h"
  14 #include <linux/neighbour.h>
  15 #include <net/if_arp.h>
  16
  17 //static int xshow_stats = 3;
  18 enum { xshow_stats = 3 };
  19
  20 static inline uint32_t rta_getattr_u32(const struct rtattr *rta)
  21 {
  22         return *(uint32_t *)RTA_DATA(rta);
  23 }
  24
  25 #ifndef RTAX_RTTVAR
  26 #define RTAX_RTTVAR RTAX_HOPS
  27 #endif
  28
  29
  30 struct filter_t {
  31         int family;
  32         int index;
  33         int state;
  34         int unused_only;
  35         inet_prefix pfx;
  36         int flushed;
  37         char *flushb;
  38         int flushp;
  39         int flushe;
  40         struct rtnl_handle *rth;
  41 } FIX_ALIASING;
  42 typedef struct filter_t filter_t;
  43
  44 #define G_filter (*(filter_t*)bb_common_bufsiz1)
  45
  46 static int flush_update(void)
  47 {
  48         if (rtnl_send(G_filter.rth, G_filter.flushb, G_filter.flushp) < 0) {
  49                 bb_perror_msg("can't send flush request");
  50                 return -1;
  51         }
  52         G_filter.flushp = 0;
  53         return 0;
  54 }
  55
  56 static unsigned nud_state_a2n(char *arg)
  57 {
  58         static const char keywords[] ALIGN1 =
  59                 /* "ip neigh show/flush" parameters: */
  60                 "permanent\0" "reachable\0"   "noarp\0"  "none\0"
  61                 "stale\0"     "incomplete\0"  "delay\0"  "probe\0"
  62                 "failed\0"
  63                 ;
  64         static uint8_t nuds[] = {
  65                 NUD_PERMANENT,NUD_REACHABLE, NUD_NOARP,NUD_NONE,
  66                 NUD_STALE,    NUD_INCOMPLETE,NUD_DELAY,NUD_PROBE,
  67                 NUD_FAILED
  68         };
  69         int id;
  70
  71         BUILD_BUG_ON(
  72                 (NUD_PERMANENT|NUD_REACHABLE| NUD_NOARP|NUD_NONE|
  73                 NUD_STALE|    NUD_INCOMPLETE|NUD_DELAY|NUD_PROBE|
  74                 NUD_FAILED) > 0xff
  75         );
  76
  77         id = index_in_substrings(keywords, arg);
  78         if (id < 0)
  79                 bb_error_msg_and_die(bb_msg_invalid_arg_to, arg, "nud state");
  80         return nuds[id];
  81 }
  82
  83 #ifndef NDA_RTA
  84 #define NDA_RTA(r) \
  85         ((struct rtattr*)(((char*)(r)) + NLMSG_ALIGN(sizeof(struct ndmsg))))
  86 #endif
  87
  88
  89 static int FAST_FUNC print_neigh(const struct sockaddr_nl *who UNUSED_PARAM,
  90                                  struct nlmsghdr *n, void *arg UNUSED_PARAM)
  91 {
  92         struct ndmsg *r = NLMSG_DATA(n);
  93         int len = n->nlmsg_len;
  94         struct rtattr *tb[NDA_MAX+1];
  95
  96         if (n->nlmsg_type != RTM_NEWNEIGH && n->nlmsg_type != RTM_DELNEIGH) {
  97                 bb_error_msg_and_die("not RTM_NEWNEIGH: %08x %08x %08x",
  98                                      n->nlmsg_len, n->nlmsg_type,
  99                                      n->nlmsg_flags);
 100         }
 101         len -= NLMSG_LENGTH(sizeof(*r));
 102         if (len < 0) {
 103                 bb_error_msg_and_die("BUG: wrong nlmsg len %d", len);
 104         }
 105
 106         if (G_filter.flushb && n->nlmsg_type != RTM_NEWNEIGH)
 107                 return 0;
 108
 109         if (G_filter.family && G_filter.family != r->ndm_family)
 110                 return 0;
 111         if (G_filter.index && G_filter.index != r->ndm_ifindex)
 112                 return 0;
 113         if (!(G_filter.state&r->ndm_state) &&
 114             !(r->ndm_flags & NTF_PROXY) &&
 115             (r->ndm_state || !(G_filter.state & 0x100)) &&
 116             (r->ndm_family != AF_DECnet))
 117                 return 0;
 118
 119         parse_rtattr(tb, NDA_MAX, NDA_RTA(r), n->nlmsg_len - NLMSG_LENGTH(sizeof(*r)));
 120
 121         if (tb[NDA_DST]) {
 122                 if (G_filter.pfx.family) {
 123                         inet_prefix dst;
 124                         memset(&dst, 0, sizeof(dst));
 125                         dst.family = r->ndm_family;
 126                         memcpy(&dst.data, RTA_DATA(tb[NDA_DST]), RTA_PAYLOAD(tb[NDA_DST]));
 127                         if (inet_addr_match(&dst, &G_filter.pfx, G_filter.pfx.bitlen))
 128                                 return 0;
 129                 }
 130         }
 131         if (G_filter.unused_only && tb[NDA_CACHEINFO]) {
 132                 struct nda_cacheinfo *ci = RTA_DATA(tb[NDA_CACHEINFO]);
 133                 if (ci->ndm_refcnt)
 134                         return 0;
 135         }
 136
 137         if (G_filter.flushb) {
 138                 struct nlmsghdr *fn;
 139                 if (NLMSG_ALIGN(G_filter.flushp) + n->nlmsg_len > G_filter.flushe) {
 140                         if (flush_update())
 141                                 return -1;
 142                 }
 143                 fn = (struct nlmsghdr*)(G_filter.flushb + NLMSG_ALIGN(G_filter.flushp));
 144                 memcpy(fn, n, n->nlmsg_len);
 145                 fn->nlmsg_type = RTM_DELNEIGH;
 146                 fn->nlmsg_flags = NLM_F_REQUEST;
 147                 fn->nlmsg_seq = ++(G_filter.rth->seq);
 148                 G_filter.flushp = (((char*)fn) + n->nlmsg_len) - G_filter.flushb;
 149                 G_filter.flushed++;
 150                 if (xshow_stats < 2)
 151                         return 0;
 152         }
 153
 154         if (tb[NDA_DST]) {
 155                 printf("%s ",
 156                        format_host(r->ndm_family,
 157                                    RTA_PAYLOAD(tb[NDA_DST]),
 158                                    RTA_DATA(tb[NDA_DST]))
 159                 );
 160         }
 161         if (!G_filter.index && r->ndm_ifindex)
 162                 printf("dev %s ", ll_index_to_name(r->ndm_ifindex));
 163         if (tb[NDA_LLADDR]) {
 164                 SPRINT_BUF(b1);
 165                 printf("lladdr %s", ll_addr_n2a(RTA_DATA(tb[NDA_LLADDR]),
 166                                                 RTA_PAYLOAD(tb[NDA_LLADDR]),
 167                                                 ARPHRD_ETHER,
 168                                                 b1, sizeof(b1)));
 169         }
 170         if (r->ndm_flags & NTF_ROUTER) {
 171                 printf(" router");
 172         }
 173         if (r->ndm_flags & NTF_PROXY) {
 174                 printf(" proxy");
 175         }
 176         if (tb[NDA_CACHEINFO] && xshow_stats) {
 177                 struct nda_cacheinfo *ci = RTA_DATA(tb[NDA_CACHEINFO]);
 178                 int hz = get_hz();
 179
 180                 if (ci->ndm_refcnt)
 181                         printf(" ref %d", ci->ndm_refcnt);
 182                 printf(" used %d/%d/%d", ci->ndm_used/hz,
 183                        ci->ndm_confirmed/hz, ci->ndm_updated/hz);
 184         }
 185
 186         if (tb[NDA_PROBES] && xshow_stats) {
 187                 uint32_t p = rta_getattr_u32(tb[NDA_PROBES]);
 188                 printf(" probes %u", p);
 189         }
 190
 191         /*if (r->ndm_state)*/ {
 192                 int nud = r->ndm_state;
 193                 char c = ' ';
 194 #define PRINT_FLAG(f) \
 195                 if (nud & NUD_##f) { \
 196                         printf("%c"#f, c); \
 197                         c = ','; \
 198                 }
 199                 PRINT_FLAG(INCOMPLETE);
 200                 PRINT_FLAG(REACHABLE);
 201                 PRINT_FLAG(STALE);
 202                 PRINT_FLAG(DELAY);
 203                 PRINT_FLAG(PROBE);
 204                 PRINT_FLAG(FAILED);
 205                 PRINT_FLAG(NOARP);
 206                 PRINT_FLAG(PERMANENT);
 207 #undef PRINT_FLAG
 208         }
 209         bb_putchar('\n');
 210
 211         return 0;
 212 }
 213
 214 static void ipneigh_reset_filter(void)
 215 {
 216         memset(&G_filter, 0, sizeof(G_filter));
 217         G_filter.state = ~0;
 218 }
 219
 220 #define MAX_ROUNDS      10
 221 /* Return value becomes exitcode. It's okay to not return at all */
 222 static int FAST_FUNC ipneigh_list_or_flush(char **argv, int flush)
 223 {
 224         static const char keywords[] ALIGN1 =
 225                 /* "ip neigh show/flush" parameters: */
 226                 "to\0" "dev\0"   "nud\0";
 227         enum {
 228                 KW_to, KW_dev, KW_nud,
 229         };
 230         struct rtnl_handle rth;
 231         struct ndmsg ndm = { 0 };
 232         char *filter_dev = NULL;
 233         int state_given = 0;
 234         int arg;
 235
 236         ipneigh_reset_filter();
 237
 238         if (flush && !*argv)
 239                 bb_error_msg_and_die(bb_msg_requires_arg, "\"ip neigh flush\"");
 240
 241         if (!G_filter.family)
 242                 G_filter.family = preferred_family;
 243
 244         G_filter.state = (flush) ?
 245                 ~(NUD_PERMANENT|NUD_NOARP) : 0xFF & ~NUD_NOARP;
 246
 247         while (*argv) {
 248                 arg = index_in_substrings(keywords, *argv);
 249                 if (arg == KW_dev) {
 250                         NEXT_ARG();
 251                         filter_dev = *argv;
 252                 } else if (arg == KW_nud) {
 253                         unsigned state;
 254                         NEXT_ARG();
 255                         if (!state_given) {
 256                                 state_given = 1;
 257                                 G_filter.state = 0;
 258                         }
 259                         if (strcmp(*argv, "all") == 0) {
 260                                 state = ~0;
 261                                 if (flush)
 262                                         state &= ~NUD_NOARP;
 263                         } else {
 264                                 state = nud_state_a2n(*argv);
 265                         }
 266                         if (state == 0)
 267                                 state = 0x100;
 268                         G_filter.state |= state;
 269                 } else {
 270                         if (arg == KW_to) {
 271                                 NEXT_ARG();
 272                         }
 273                         get_prefix(&G_filter.pfx, *argv, G_filter.family);
 274                         if (G_filter.family == AF_UNSPEC)
 275                                 G_filter.family = G_filter.pfx.family;
 276                 }
 277                 argv++;
 278         }
 279
 280         xrtnl_open(&rth);
 281         ll_init_map(&rth);
 282
 283         if (filter_dev)  {
 284                 G_filter.index = xll_name_to_index(filter_dev);
 285                 if (G_filter.index == 0) {
 286                         bb_error_msg_and_die("can't find device '%s'", filter_dev);
 287                 }
 288         }
 289
 290         if (flush) {
 291                 int round = 0;
 292                 char flushb[4096-512];
 293                 G_filter.flushb = flushb;
 294                 G_filter.flushp = 0;
 295                 G_filter.flushe = sizeof(flushb);
 296                 G_filter.state &= ~NUD_FAILED;
 297                 G_filter.rth = &rth;
 298
 299                 while (round < MAX_ROUNDS) {
 300                         if (xrtnl_wilddump_request(&rth, G_filter.family, RTM_GETNEIGH) < 0) {
 301                                 bb_perror_msg_and_die("can't send dump request");
 302                         }
 303                         G_filter.flushed = 0;
 304                         if (xrtnl_dump_filter(&rth, print_neigh, NULL) < 0) {
 305                                 bb_perror_msg_and_die("flush terminated");
 306                         }
 307                         if (G_filter.flushed == 0) {
 308                                 if (round == 0)
 309                                         puts("Nothing to flush");
 310                                 else
 311                                         printf("*** Flush is complete after %d round(s) ***\n", round);
 312                                 return 0;
 313                         }
 314                         round++;
 315                         if (flush_update() < 0)
 316                                 xfunc_die();
 317                         printf("\n*** Round %d, deleting %d entries ***\n", round, G_filter.flushed);
 318                 }
 319                 bb_error_msg_and_die("*** Flush not complete bailing out after %d rounds", MAX_ROUNDS);
 320         }
 321
 322         ndm.ndm_family = G_filter.family;
 323
 324         if (rtnl_dump_request(&rth, RTM_GETNEIGH, &ndm, sizeof(struct ndmsg)) < 0) {
 325                 bb_perror_msg_and_die("can't send dump request");
 326         }
 327
 328         if (xrtnl_dump_filter(&rth, print_neigh, NULL) < 0) {
 329                 bb_error_msg_and_die("dump terminated");
 330         }
 331
 332         return 0;
 333 }
 334
 335 /* Return value becomes exitcode. It's okay to not return at all */
 336 int FAST_FUNC do_ipneigh(char **argv)
 337 {
 338         static const char ip_neigh_commands[] ALIGN1 =
 339                 /*0-1*/ "show\0"  "flush\0";
 340         int command_num;
 341
 342         if (!*argv)
 343                 return ipneigh_list_or_flush(argv, 0);
 344
 345         command_num = index_in_substrings(ip_neigh_commands, *argv);
 346         switch (command_num) {
 347                 case 0: /* show */
 348                         return ipneigh_list_or_flush(argv + 1, 0);
 349                 case 1: /* flush */
 350                         return ipneigh_list_or_flush(argv + 1, 1);
 351         }
 352         invarg_1_to_2(*argv, applet_name);
 353         return 1;
 354 }