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 #include "ip_common.h"  /* #include "libbb.h" is inside */
  10 #include "common_bufsiz.h"
  11 #include "rt_names.h"
  12 #include "utils.h"
  13 #include <linux/neighbour.h>
  14 #include <net/if_arp.h>
  15
  16 //static int xshow_stats = 3;
  17 enum { xshow_stats = 3 };
  18
  19 static inline uint32_t rta_getattr_u32(const struct rtattr *rta)
  20 {
  21         return *(uint32_t *)RTA_DATA(rta);
  22 }
  23
  24 #ifndef RTAX_RTTVAR
  25 #define RTAX_RTTVAR RTAX_HOPS
  26 #endif
  27
  28
  29 struct filter_t {
  30         int family;
  31         int index;
  32         int state;
  33         int unused_only;
  34         inet_prefix pfx;
  35         int flushed;
  36         char *flushb;
  37         int flushp;
  38         int flushe;
  39         struct rtnl_handle *rth;
  40 } FIX_ALIASING;
  41 typedef struct filter_t filter_t;
  42
  43 #define G_filter (*(filter_t*)bb_common_bufsiz1)
  44 #define INIT_G() do { setup_common_bufsiz(); } while (0)
  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[] ALIGN1 = {
  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         ) {
 118                 return 0;
 119         }
 120
 121         parse_rtattr(tb, NDA_MAX, NDA_RTA(r), n->nlmsg_len - NLMSG_LENGTH(sizeof(*r)));
 122
 123         if (tb[NDA_DST]) {
 124                 if (G_filter.pfx.family) {
 125                         inet_prefix dst;
 126                         memset(&dst, 0, sizeof(dst));
 127                         dst.family = r->ndm_family;
 128                         memcpy(&dst.data, RTA_DATA(tb[NDA_DST]), RTA_PAYLOAD(tb[NDA_DST]));
 129                         if (inet_addr_match(&dst, &G_filter.pfx, G_filter.pfx.bitlen))
 130                                 return 0;
 131                 }
 132         }
 133         if (G_filter.unused_only && tb[NDA_CACHEINFO]) {
 134                 struct nda_cacheinfo *ci = RTA_DATA(tb[NDA_CACHEINFO]);
 135                 if (ci->ndm_refcnt)
 136                         return 0;
 137         }
 138
 139         if (G_filter.flushb) {
 140                 struct nlmsghdr *fn;
 141                 if (NLMSG_ALIGN(G_filter.flushp) + n->nlmsg_len > G_filter.flushe) {
 142                         if (flush_update())
 143                                 return -1;
 144                 }
 145                 fn = (struct nlmsghdr*)(G_filter.flushb + NLMSG_ALIGN(G_filter.flushp));
 146                 memcpy(fn, n, n->nlmsg_len);
 147                 fn->nlmsg_type = RTM_DELNEIGH;
 148                 fn->nlmsg_flags = NLM_F_REQUEST;
 149                 fn->nlmsg_seq = ++(G_filter.rth->seq);
 150                 G_filter.flushp = (((char*)fn) + n->nlmsg_len) - G_filter.flushb;
 151                 G_filter.flushed++;
 152                 if (xshow_stats < 2)
 153                         return 0;
 154         }
 155
 156         if (tb[NDA_DST]) {
 157                 printf("%s ",
 158                        format_host(r->ndm_family,
 159                                    RTA_PAYLOAD(tb[NDA_DST]),
 160                                    RTA_DATA(tb[NDA_DST]))
 161                 );
 162         }
 163         if (!G_filter.index && r->ndm_ifindex)
 164                 printf("dev %s ", ll_index_to_name(r->ndm_ifindex));
 165         if (tb[NDA_LLADDR]) {
 166                 SPRINT_BUF(b1);
 167                 printf("lladdr %s", ll_addr_n2a(RTA_DATA(tb[NDA_LLADDR]),
 168                                                 RTA_PAYLOAD(tb[NDA_LLADDR]),
 169                                                 ARPHRD_ETHER,
 170                                                 b1, sizeof(b1)));
 171         }
 172         if (r->ndm_flags & NTF_ROUTER) {
 173                 printf(" router");
 174         }
 175         if (r->ndm_flags & NTF_PROXY) {
 176                 printf(" proxy");
 177         }
 178         if (tb[NDA_CACHEINFO] && xshow_stats) {
 179                 struct nda_cacheinfo *ci = RTA_DATA(tb[NDA_CACHEINFO]);
 180                 int hz = get_hz();
 181
 182                 if (ci->ndm_refcnt)
 183                         printf(" ref %d", ci->ndm_refcnt);
 184                 printf(" used %d/%d/%d", ci->ndm_used/hz,
 185                        ci->ndm_confirmed/hz, ci->ndm_updated/hz);
 186         }
 187
 188         if (tb[NDA_PROBES] && xshow_stats) {
 189                 uint32_t p = rta_getattr_u32(tb[NDA_PROBES]);
 190                 printf(" probes %u", p);
 191         }
 192
 193         /*if (r->ndm_state)*/ {
 194                 int nud = r->ndm_state;
 195                 char c = ' ';
 196 #define PRINT_FLAG(f) \
 197                 if (nud & NUD_##f) { \
 198                         printf("%c"#f, c); \
 199                         c = ','; \
 200                 }
 201                 PRINT_FLAG(INCOMPLETE);
 202                 PRINT_FLAG(REACHABLE);
 203                 PRINT_FLAG(STALE);
 204                 PRINT_FLAG(DELAY);
 205                 PRINT_FLAG(PROBE);
 206                 PRINT_FLAG(FAILED);
 207                 PRINT_FLAG(NOARP);
 208                 PRINT_FLAG(PERMANENT);
 209 #undef PRINT_FLAG
 210         }
 211         bb_putchar('\n');
 212
 213         return 0;
 214 }
 215
 216 static void ipneigh_reset_filter(void)
 217 {
 218         memset(&G_filter, 0, sizeof(G_filter));
 219         G_filter.state = ~0;
 220 }
 221
 222 #define MAX_ROUNDS      10
 223 /* Return value becomes exitcode. It's okay to not return at all */
 224 static int FAST_FUNC ipneigh_list_or_flush(char **argv, int flush)
 225 {
 226         static const char keywords[] ALIGN1 =
 227                 /* "ip neigh show/flush" parameters: */
 228                 "to\0" "dev\0"   "nud\0";
 229         enum {
 230                 KW_to, KW_dev, KW_nud,
 231         };
 232         struct rtnl_handle rth;
 233         struct ndmsg ndm = { 0 };
 234         char *filter_dev = NULL;
 235         int state_given = 0;
 236         int arg;
 237
 238         ipneigh_reset_filter();
 239
 240         if (flush && !*argv)
 241                 bb_error_msg_and_die(bb_msg_requires_arg, "\"ip neigh flush\"");
 242
 243         if (!G_filter.family)
 244                 G_filter.family = preferred_family;
 245
 246         G_filter.state = (flush) ?
 247                 ~(NUD_PERMANENT|NUD_NOARP) : 0xFF & ~NUD_NOARP;
 248
 249         while (*argv) {
 250                 arg = index_in_substrings(keywords, *argv);
 251                 if (arg == KW_dev) {
 252                         NEXT_ARG();
 253                         filter_dev = *argv;
 254                 } else if (arg == KW_nud) {
 255                         unsigned state;
 256                         NEXT_ARG();
 257                         if (!state_given) {
 258                                 state_given = 1;
 259                                 G_filter.state = 0;
 260                         }
 261                         if (strcmp(*argv, "all") == 0) {
 262                                 state = ~0;
 263                                 if (flush)
 264                                         state &= ~NUD_NOARP;
 265                         } else {
 266                                 state = nud_state_a2n(*argv);
 267                         }
 268                         if (state == 0)
 269                                 state = 0x100;
 270                         G_filter.state |= state;
 271                 } else {
 272                         if (arg == KW_to) {
 273                                 NEXT_ARG();
 274                         }
 275                         get_prefix(&G_filter.pfx, *argv, G_filter.family);
 276                         if (G_filter.family == AF_UNSPEC)
 277                                 G_filter.family = G_filter.pfx.family;
 278                 }
 279                 argv++;
 280         }
 281
 282         xrtnl_open(&rth);
 283         ll_init_map(&rth);
 284
 285         if (filter_dev)  {
 286                 G_filter.index = xll_name_to_index(filter_dev);
 287                 if (G_filter.index == 0) {
 288                         bb_error_msg_and_die("can't find device '%s'", filter_dev);
 289                 }
 290         }
 291
 292         if (flush) {
 293                 int round = 0;
 294                 char flushb[4096-512];
 295                 G_filter.flushb = flushb;
 296                 G_filter.flushp = 0;
 297                 G_filter.flushe = sizeof(flushb);
 298                 G_filter.state &= ~NUD_FAILED;
 299                 G_filter.rth = &rth;
 300
 301                 while (round < MAX_ROUNDS) {
 302                         if (xrtnl_wilddump_request(&rth, G_filter.family, RTM_GETNEIGH) < 0) {
 303                                 bb_perror_msg_and_die("can't send dump request");
 304                         }
 305                         G_filter.flushed = 0;
 306                         if (xrtnl_dump_filter(&rth, print_neigh, NULL) < 0) {
 307                                 bb_perror_msg_and_die("flush terminated");
 308                         }
 309                         if (G_filter.flushed == 0) {
 310                                 if (round == 0)
 311                                         puts("Nothing to flush");
 312                                 else
 313                                         printf("*** Flush is complete after %d round(s) ***\n", round);
 314                                 return 0;
 315                         }
 316                         round++;
 317                         if (flush_update() < 0)
 318                                 xfunc_die();
 319                         printf("\n*** Round %d, deleting %d entries ***\n", round, G_filter.flushed);
 320                 }
 321                 bb_error_msg_and_die("*** Flush not complete bailing out after %d rounds", MAX_ROUNDS);
 322         }
 323
 324         ndm.ndm_family = G_filter.family;
 325
 326         if (rtnl_dump_request(&rth, RTM_GETNEIGH, &ndm, sizeof(struct ndmsg)) < 0) {
 327                 bb_perror_msg_and_die("can't send dump request");
 328         }
 329
 330         if (xrtnl_dump_filter(&rth, print_neigh, NULL) < 0) {
 331                 bb_error_msg_and_die("dump terminated");
 332         }
 333
 334         return 0;
 335 }
 336
 337 /* Return value becomes exitcode. It's okay to not return at all */
 338 int FAST_FUNC do_ipneigh(char **argv)
 339 {
 340         static const char ip_neigh_commands[] ALIGN1 =
 341                 /*0-1*/ "show\0"  "flush\0";
 342         int command_num;
 343
 344         INIT_G();
 345
 346         if (!*argv)
 347                 return ipneigh_list_or_flush(argv, 0);
 348
 349         command_num = index_in_substrings(ip_neigh_commands, *argv);
 350         switch (command_num) {
 351                 case 0: /* show */
 352                         return ipneigh_list_or_flush(argv + 1, 0);
 353                 case 1: /* flush */
 354                         return ipneigh_list_or_flush(argv + 1, 1);
 355         }
 356         invarg_1_to_2(*argv, applet_name);
 357         return 1;
 358 }