vnet/vnet/ethernet/arp.c

   1 /*
   2  * ethernet/arp.c: IP v4 ARP node
   3  *
   4  * Copyright (c) 2010 Cisco and/or its affiliates.
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at:
   8  *
   9  *     http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  */
  17
  18 #include <vnet/ip/ip.h>
  19 #include <vnet/ethernet/ethernet.h>
  20 #include <vnet/ethernet/arp_packet.h>
  21 #include <vnet/l2/l2_input.h>
  22 #include <vppinfra/mhash.h>
  23
  24 void vl_api_rpc_call_main_thread (void *fp, u8 * data, u32 data_length);
  25
  26 typedef struct {
  27   u32 sw_if_index;
  28   u32 fib_index;
  29   ip4_address_t ip4_address;
  30 } ethernet_arp_ip4_key_t;
  31
  32 typedef struct {
  33   ethernet_arp_ip4_key_t key;
  34   u8 ethernet_address[6];
  35
  36   u16 flags;
  37 #define ETHERNET_ARP_IP4_ENTRY_FLAG_STATIC (1 << 0)
  38 #define ETHERNET_ARP_IP4_ENTRY_FLAG_GLEAN  (2 << 0)
  39
  40   u64 cpu_time_last_updated;
  41
  42   u32 * adjacencies;
  43 } ethernet_arp_ip4_entry_t;
  44
  45 typedef struct {
  46   u32 lo_addr;
  47   u32 hi_addr;
  48   u32 fib_index;
  49 } ethernet_proxy_arp_t;
  50
  51 typedef struct {
  52   u32 next_index;
  53   uword node_index;
  54   uword type_opaque;
  55   uword data;
  56   /* Used for arp event notification only */
  57   void * data_callback;
  58   u32 pid;
  59 } pending_resolution_t;
  60
  61 typedef struct {
  62   /* Hash tables mapping name to opcode. */
  63   uword * opcode_by_name;
  64
  65   /* lite beer "glean" adjacency handling */
  66   uword * pending_resolutions_by_address;
  67   pending_resolution_t * pending_resolutions;
  68
  69   /* Mac address change notification */
  70   uword * mac_changes_by_address;
  71   pending_resolution_t * mac_changes;
  72
  73   ethernet_arp_ip4_entry_t * ip4_entry_pool;
  74
  75   mhash_t ip4_entry_by_key;
  76
  77   /* ARP attack mitigation */
  78   u32 arp_delete_rotor;
  79   u32 limit_arp_cache_size;
  80
  81   /* Proxy arp vector */
  82   ethernet_proxy_arp_t * proxy_arps;
  83 } ethernet_arp_main_t;
  84
  85 static ethernet_arp_main_t ethernet_arp_main;
  86
  87 static u8 * format_ethernet_arp_hardware_type (u8 * s, va_list * va)
  88 {
  89   ethernet_arp_hardware_type_t h = va_arg (*va, ethernet_arp_hardware_type_t);
  90   char * t = 0;
  91   switch (h)
  92     {
  93 #define _(n,f) case n: t = #f; break;
  94       foreach_ethernet_arp_hardware_type;
  95 #undef _
  96
  97     default:
  98       return format (s, "unknown 0x%x", h);
  99     }
 100
 101   return format (s, "%s", t);
 102 }
 103
 104 static u8 * format_ethernet_arp_opcode (u8 * s, va_list * va)
 105 {
 106   ethernet_arp_opcode_t o = va_arg (*va, ethernet_arp_opcode_t);
 107   char * t = 0;
 108   switch (o)
 109     {
 110 #define _(f) case ETHERNET_ARP_OPCODE_##f: t = #f; break;
 111       foreach_ethernet_arp_opcode;
 112 #undef _
 113
 114     default:
 115       return format (s, "unknown 0x%x", o);
 116     }
 117
 118   return format (s, "%s", t);
 119 }
 120
 121 static uword
 122 unformat_ethernet_arp_opcode_host_byte_order (unformat_input_t * input,
 123                                               va_list * args)
 124 {
 125   int * result = va_arg (*args, int *);
 126   ethernet_arp_main_t * am = &ethernet_arp_main;
 127   int x, i;
 128
 129   /* Numeric opcode. */
 130   if (unformat (input, "0x%x", &x)
 131       || unformat (input, "%d", &x))
 132     {
 133       if (x >= (1 << 16))
 134         return 0;
 135       *result = x;
 136       return 1;
 137     }
 138
 139   /* Named type. */
 140   if (unformat_user (input, unformat_vlib_number_by_name,
 141                      am->opcode_by_name, &i))
 142     {
 143       *result = i;
 144       return 1;
 145     }
 146
 147   return 0;
 148 }
 149
 150 static uword
 151 unformat_ethernet_arp_opcode_net_byte_order (unformat_input_t * input,
 152                                              va_list * args)
 153 {
 154   int * result = va_arg (*args, int *);
 155   if (! unformat_user (input, unformat_ethernet_arp_opcode_host_byte_order, result))
 156     return 0;
 157
 158   *result = clib_host_to_net_u16 ((u16) *result);
 159   return 1;
 160 }
 161
 162 static u8 * format_ethernet_arp_header (u8 * s, va_list * va)
 163 {
 164   ethernet_arp_header_t * a = va_arg (*va, ethernet_arp_header_t *);
 165   u32 max_header_bytes = va_arg (*va, u32);
 166   uword indent;
 167   u16 l2_type, l3_type;
 168
 169   if (max_header_bytes != 0 && sizeof (a[0]) > max_header_bytes)
 170     return format (s, "ARP header truncated");
 171
 172   l2_type = clib_net_to_host_u16 (a->l2_type);
 173   l3_type = clib_net_to_host_u16 (a->l3_type);
 174
 175   indent = format_get_indent (s);
 176
 177   s = format (s, "%U, type %U/%U, address size %d/%d",
 178               format_ethernet_arp_opcode, clib_net_to_host_u16 (a->opcode),
 179               format_ethernet_arp_hardware_type, l2_type,
 180               format_ethernet_type, l3_type,
 181               a->n_l2_address_bytes, a->n_l3_address_bytes);
 182
 183   if (l2_type == ETHERNET_ARP_HARDWARE_TYPE_ethernet
 184       && l3_type == ETHERNET_TYPE_IP4)
 185     {
 186       s = format (s, "\n%U%U/%U -> %U/%U",
 187                   format_white_space, indent,
 188                   format_ethernet_address, a->ip4_over_ethernet[0].ethernet,
 189                   format_ip4_address, &a->ip4_over_ethernet[0].ip4,
 190                   format_ethernet_address, a->ip4_over_ethernet[1].ethernet,
 191                   format_ip4_address, &a->ip4_over_ethernet[1].ip4);
 192     }
 193   else
 194     {
 195       uword n2 = a->n_l2_address_bytes;
 196       uword n3 = a->n_l3_address_bytes;
 197       s = format (s, "\n%U%U/%U -> %U/%U",
 198                   format_white_space, indent,
 199                   format_hex_bytes, a->data + 0*n2 + 0*n3, n2,
 200                   format_hex_bytes, a->data + 1*n2 + 0*n3, n3,
 201                   format_hex_bytes, a->data + 1*n2 + 1*n3, n2,
 202                   format_hex_bytes, a->data + 2*n2 + 1*n3, n3);
 203     }
 204
 205   return s;
 206 }
 207
 208 static u8 * format_ethernet_arp_ip4_entry (u8 * s, va_list * va)
 209 {
 210   vnet_main_t * vnm = va_arg (*va, vnet_main_t *);
 211   ethernet_arp_ip4_entry_t * e = va_arg (*va, ethernet_arp_ip4_entry_t *);
 212   vnet_sw_interface_t * si;
 213   ip4_fib_t * fib;
 214   u8 * flags = 0;
 215
 216   if (! e)
 217     return format (s, "%=12s%=6s%=16s%=6s%=20s%=24s", "Time", "FIB", "IP4",
 218                    "Flags", "Ethernet", "Interface");
 219
 220   fib = find_ip4_fib_by_table_index_or_id (&ip4_main, e->key.fib_index,
 221                                            IP4_ROUTE_FLAG_FIB_INDEX);
 222   si = vnet_get_sw_interface (vnm, e->key.sw_if_index);
 223
 224   if (e->flags & ETHERNET_ARP_IP4_ENTRY_FLAG_GLEAN)
 225     flags = format(flags, "G");
 226
 227   if (e->flags & ETHERNET_ARP_IP4_ENTRY_FLAG_STATIC)
 228     flags = format(flags, "S");
 229
 230   s = format (s, "%=12U%=6u%=16U%=6s%=20U%=24U",
 231               format_vlib_cpu_time, vnm->vlib_main, e->cpu_time_last_updated,
 232               fib->table_id,
 233               format_ip4_address, &e->key.ip4_address,
 234               flags ? (char *) flags : "",
 235               format_ethernet_address, e->ethernet_address,
 236               format_vnet_sw_interface_name, vnm, si);
 237
 238   vec_free(flags);
 239   return s;
 240 }
 241
 242 typedef struct {
 243   u8 packet_data[64];
 244 } ethernet_arp_input_trace_t;
 245
 246 static u8 * format_ethernet_arp_input_trace (u8 * s, va_list * va)
 247 {
 248   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*va, vlib_main_t *);
 249   CLIB_UNUSED (vlib_node_t * node) = va_arg (*va, vlib_node_t *);
 250   ethernet_arp_input_trace_t * t = va_arg (*va, ethernet_arp_input_trace_t *);
 251
 252   s = format (s, "%U",
 253               format_ethernet_arp_header,
 254               t->packet_data, sizeof (t->packet_data));
 255
 256   return s;
 257 }
 258
 259 clib_error_t *
 260 ethernet_arp_sw_interface_up_down (vnet_main_t * vnm,
 261                                    u32 sw_if_index,
 262                                    u32 flags)
 263 {
 264   ethernet_arp_main_t * am = &ethernet_arp_main;
 265   ethernet_arp_ip4_entry_t * e;
 266   u32 i;
 267   u32 * to_add_del = 0;
 268
 269   pool_foreach (e, am->ip4_entry_pool, ({
 270     if (e->key.sw_if_index == sw_if_index)
 271         vec_add1 (to_add_del, e - am->ip4_entry_pool);
 272   }));
 273
 274   for (i = 0; i < vec_len (to_add_del); i++)
 275     {
 276       ethernet_arp_ip4_over_ethernet_address_t arp_add;
 277       e = pool_elt_at_index (am->ip4_entry_pool, to_add_del[i]);
 278
 279       clib_memcpy (&arp_add.ethernet, e->ethernet_address, 6);
 280       arp_add.ip4.as_u32 = e->key.ip4_address.as_u32;
 281
 282       if (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP)
 283         {
 284           vnet_arp_set_ip4_over_ethernet (vnm,
 285               e->key.sw_if_index, e->key.fib_index, &arp_add,
 286               e->flags & ETHERNET_ARP_IP4_ENTRY_FLAG_STATIC);
 287         }
 288       else if ((e->flags & ETHERNET_ARP_IP4_ENTRY_FLAG_STATIC) == 0)
 289         {
 290           vnet_arp_unset_ip4_over_ethernet (vnm,
 291               e->key.sw_if_index, e->key.fib_index, &arp_add);
 292         }
 293     }
 294
 295   vec_free (to_add_del);
 296   return 0;
 297 }
 298
 299 VNET_SW_INTERFACE_ADMIN_UP_DOWN_FUNCTION (ethernet_arp_sw_interface_up_down);
 300
 301 static int
 302 vnet_arp_set_ip4_over_ethernet_internal (vnet_main_t * vnm,
 303                                          u32 sw_if_index,
 304                                          u32 fib_index,
 305                                          void * a_arg,
 306                                          int is_static);
 307
 308 static int
 309 vnet_arp_unset_ip4_over_ethernet_internal (vnet_main_t * vnm,
 310                                            u32 sw_if_index,
 311                                            u32 fib_index,
 312                                            void * a_arg);
 313
 314 typedef struct {
 315   u32 sw_if_index;
 316   u32 fib_index;
 317   ethernet_arp_ip4_over_ethernet_address_t a;
 318   int is_static;
 319   int is_remove; /* set is_remove=1 to clear arp entry */
 320 } vnet_arp_set_ip4_over_ethernet_rpc_args_t;
 321
 322 static void set_ip4_over_ethernet_rpc_callback
 323 ( vnet_arp_set_ip4_over_ethernet_rpc_args_t * a)
 324 {
 325   vnet_main_t * vm = vnet_get_main();
 326   ASSERT(os_get_cpu_number() == 0);
 327
 328   if (a->is_remove)
 329     vnet_arp_unset_ip4_over_ethernet_internal(vm,
 330                                               a->sw_if_index,
 331                                               a->fib_index,
 332                                               &(a->a));
 333   else
 334     vnet_arp_set_ip4_over_ethernet_internal (vm,
 335                                              a->sw_if_index,
 336                                              a->fib_index,
 337                                              &(a->a),
 338                                              a->is_static);
 339 }
 340
 341 int
 342 vnet_arp_set_ip4_over_ethernet (vnet_main_t * vnm,
 343                                 u32 sw_if_index,
 344                                 u32 fib_index,
 345                                 void * a_arg,
 346                                 int is_static)
 347 {
 348   ethernet_arp_ip4_over_ethernet_address_t * a = a_arg;
 349   vnet_arp_set_ip4_over_ethernet_rpc_args_t args;
 350
 351   args.sw_if_index = sw_if_index;
 352   args.fib_index = fib_index;
 353   args.is_static = is_static;
 354   args.is_remove = 0;
 355   clib_memcpy (&args.a, a, sizeof (*a));
 356
 357   vl_api_rpc_call_main_thread (set_ip4_over_ethernet_rpc_callback,
 358                                (u8 *) &args, sizeof (args));
 359   return 0;
 360 }
 361
 362 int
 363 vnet_arp_set_ip4_over_ethernet_internal (vnet_main_t * vnm,
 364                                          u32 sw_if_index,
 365                                          u32 fib_index,
 366                                          void * a_arg,
 367                                          int is_static)
 368 {
 369   ethernet_arp_ip4_key_t k;
 370   ethernet_arp_ip4_entry_t * e = 0;
 371   ethernet_arp_main_t * am = &ethernet_arp_main;
 372   ethernet_arp_ip4_over_ethernet_address_t * a = a_arg;
 373   vlib_main_t * vm = vlib_get_main();
 374   ip4_main_t * im = &ip4_main;
 375   ip_lookup_main_t * lm = &im->lookup_main;
 376   int make_new_arp_cache_entry=1;
 377   uword * p;
 378   ip4_add_del_route_args_t args;
 379   ip_adjacency_t adj, * existing_adj;
 380   pending_resolution_t * pr, * mc;
 381
 382   u32 next_index;
 383   u32 adj_index;
 384
 385   fib_index = (fib_index != (u32)~0)
 386     ? fib_index : im->fib_index_by_sw_if_index[sw_if_index];
 387
 388   k.sw_if_index = sw_if_index;
 389   k.ip4_address = a->ip4;
 390   k.fib_index = fib_index;
 391
 392   p = mhash_get (&am->ip4_entry_by_key, &k);
 393   if (p)
 394     {
 395       e = pool_elt_at_index (am->ip4_entry_pool, p[0]);
 396
 397       /* Refuse to over-write static arp. */
 398       if (!is_static &&
 399           (e->flags & ETHERNET_ARP_IP4_ENTRY_FLAG_STATIC))
 400         return -2;
 401       make_new_arp_cache_entry = 0;
 402     }
 403
 404   /* Note: always install the route. It might have been deleted */
 405   memset(&adj, 0, sizeof(adj));
 406   adj.lookup_next_index = IP_LOOKUP_NEXT_REWRITE;
 407   adj.n_adj = 1; /*  otherwise signature compare fails */
 408
 409   vnet_rewrite_for_sw_interface
 410     (vnm,
 411      VNET_L3_PACKET_TYPE_IP4,
 412      sw_if_index,
 413      ip4_rewrite_node.index,
 414      a->ethernet,               /* destination address */
 415      &adj.rewrite_header,
 416      sizeof (adj.rewrite_data));
 417
 418   /* result of this lookup should be next-hop adjacency */
 419   adj_index = ip4_fib_lookup_with_table (im, fib_index, &a->ip4, 0);
 420   existing_adj = ip_get_adjacency(lm, adj_index);
 421
 422   if (existing_adj->lookup_next_index == IP_LOOKUP_NEXT_ARP &&
 423       existing_adj->arp.next_hop.ip4.as_u32 == a->ip4.as_u32)
 424     {
 425       u32 * ai;
 426       u32 * adjs = vec_dup(e->adjacencies);
 427       /* Update all adj assigned to this arp entry */
 428       vec_foreach(ai, adjs)
 429         {
 430           int i;
 431           ip_adjacency_t * uadj = ip_get_adjacency(lm, *ai);
 432           for (i = 0; i < uadj->n_adj; i++)
 433             if (uadj[i].lookup_next_index == IP_LOOKUP_NEXT_ARP &&
 434                 uadj[i].arp.next_hop.ip4.as_u32 == a->ip4.as_u32)
 435               ip_update_adjacency (lm, *ai + i, &adj);
 436         }
 437       vec_free(adjs);
 438     }
 439   else
 440     {
 441       /* Check that new adjacency actually isn't exactly the same as
 442        *  what is already there. If we over-write the adjacency with
 443        *  exactly the same info, its technically a new adjacency with
 444        *  new counters, but to user it appears as counters reset.
 445        */
 446       if (vnet_ip_adjacency_share_compare (&adj, existing_adj) == 0) {
 447         /* create new adj */
 448         args.table_index_or_table_id = fib_index;
 449         args.flags = IP4_ROUTE_FLAG_FIB_INDEX | IP4_ROUTE_FLAG_ADD | IP4_ROUTE_FLAG_NEIGHBOR;
 450         args.dst_address = a->ip4;
 451         args.dst_address_length = 32;
 452         args.adj_index = ~0;
 453         args.add_adj = &adj;
 454         args.n_add_adj = 1;
 455         ip4_add_del_route (im, &args);
 456       }
 457     }
 458
 459   if (make_new_arp_cache_entry)
 460     {
 461       pool_get (am->ip4_entry_pool, e);
 462       mhash_set (&am->ip4_entry_by_key, &k,
 463                  e - am->ip4_entry_pool,
 464                  /* old value */ 0);
 465       e->key = k;
 466     }
 467
 468   /* Update time stamp and ethernet address. */
 469   clib_memcpy (e->ethernet_address, a->ethernet, sizeof (e->ethernet_address));
 470   e->cpu_time_last_updated = clib_cpu_time_now ();
 471   if (is_static)
 472     e->flags |= ETHERNET_ARP_IP4_ENTRY_FLAG_STATIC;
 473
 474   /* Customer(s) waiting for this address to be resolved? */
 475   p = hash_get (am->pending_resolutions_by_address, a->ip4.as_u32);
 476   if (p)
 477     {
 478       next_index = p[0];
 479
 480       while (next_index != (u32)~0)
 481         {
 482           pr = pool_elt_at_index (am->pending_resolutions, next_index);
 483           vlib_process_signal_event (vm, pr->node_index,
 484                                      pr->type_opaque,
 485                                      pr->data);
 486           next_index = pr->next_index;
 487           pool_put (am->pending_resolutions, pr);
 488         }
 489
 490       hash_unset (am->pending_resolutions_by_address, a->ip4.as_u32);
 491     }
 492
 493   /* Customer(s) requesting ARP event for this address? */
 494   p = hash_get (am->mac_changes_by_address, a->ip4.as_u32);
 495   if (p)
 496     {
 497       next_index = p[0];
 498
 499       while (next_index != (u32)~0)
 500         {
 501           int (*fp)(u32, u8 *, u32, u32);
 502           int rv = 1;
 503           mc = pool_elt_at_index (am->mac_changes, next_index);
 504           fp = mc->data_callback;
 505
 506           /* Call the user's data callback, return 1 to suppress dup events */
 507           if (fp)
 508             rv = (*fp)(mc->data, a->ethernet, sw_if_index, 0);
 509
 510           /*
 511            * Signal the resolver process, as long as the user
 512            * says they want to be notified
 513            */
 514           if (rv == 0)
 515             vlib_process_signal_event (vm, mc->node_index,
 516                                        mc->type_opaque,
 517                                        mc->data);
 518           next_index = mc->next_index;
 519         }
 520     }
 521
 522   return 0;
 523 }
 524
 525 void vnet_register_ip4_arp_resolution_event (vnet_main_t * vnm,
 526                                              void * address_arg,
 527                                              uword node_index,
 528                                              uword type_opaque,
 529                                              uword data)
 530 {
 531   ethernet_arp_main_t * am = &ethernet_arp_main;
 532   ip4_address_t * address = address_arg;
 533   uword * p;
 534   pending_resolution_t * pr;
 535
 536   pool_get (am->pending_resolutions, pr);
 537
 538   pr->next_index = ~0;
 539   pr->node_index = node_index;
 540   pr->type_opaque = type_opaque;
 541   pr->data = data;
 542   pr->data_callback = 0;
 543
 544   p = hash_get (am->pending_resolutions_by_address, address->as_u32);
 545   if (p)
 546     {
 547       /* Insert new resolution at the head of the list */
 548       pr->next_index = p[0];
 549       hash_unset (am->pending_resolutions_by_address, address->as_u32);
 550     }
 551
 552   hash_set (am->pending_resolutions_by_address, address->as_u32,
 553             pr - am->pending_resolutions);
 554 }
 555
 556 int vnet_add_del_ip4_arp_change_event (vnet_main_t * vnm,
 557                                        void * data_callback,
 558                                        u32 pid,
 559                                        void * address_arg,
 560                                        uword node_index,
 561                                        uword type_opaque,
 562                                        uword data, int is_add)
 563 {
 564   ethernet_arp_main_t * am = &ethernet_arp_main;
 565   ip4_address_t * address = address_arg;
 566   uword * p;
 567   pending_resolution_t * mc;
 568   void (*fp)(u32, u8 *) = data_callback;
 569
 570   if (is_add)
 571     {
 572       pool_get (am->mac_changes, mc);
 573
 574       mc->next_index = ~0;
 575       mc->node_index = node_index;
 576       mc->type_opaque = type_opaque;
 577       mc->data = data;
 578       mc->data_callback = data_callback;
 579       mc->pid = pid;
 580
 581       p = hash_get (am->mac_changes_by_address, address->as_u32);
 582       if (p)
 583         {
 584           /* Insert new resolution at the head of the list */
 585           mc->next_index = p[0];
 586           hash_unset (am->mac_changes_by_address, address->as_u32);
 587         }
 588
 589       hash_set (am->mac_changes_by_address, address->as_u32,
 590                 mc - am->mac_changes);
 591       return 0;
 592     }
 593   else
 594     {
 595       u32 index;
 596       pending_resolution_t * mc_last = 0;
 597
 598       p = hash_get (am->mac_changes_by_address, address->as_u32);
 599       if (p == 0)
 600         return VNET_API_ERROR_NO_SUCH_ENTRY;
 601
 602       index = p[0];
 603
 604       while (index != (u32)~0)
 605         {
 606           mc = pool_elt_at_index (am->mac_changes, index);
 607           if (mc->node_index == node_index &&
 608               mc->type_opaque == type_opaque &&
 609               mc->pid == pid)
 610             {
 611               /* Clients may need to clean up pool entries, too */
 612               if (fp)
 613                 (*fp)(mc->data, 0 /* no new mac addrs */);
 614               if (index == p[0])
 615                 {
 616                   hash_unset (am->mac_changes_by_address, address->as_u32);
 617                   if (mc->next_index != ~0)
 618                     hash_set (am->mac_changes_by_address, address->as_u32,
 619                               mc->next_index);
 620                   pool_put (am->mac_changes, mc);
 621                   return 0;
 622                 }
 623               else
 624                 {
 625                   ASSERT(mc_last);
 626                   mc_last->next_index = mc->next_index;
 627                   pool_put (am->mac_changes, mc);
 628                   return 0;
 629                 }
 630             }
 631           mc_last = mc;
 632           index = mc->next_index;
 633         }
 634
 635       return VNET_API_ERROR_NO_SUCH_ENTRY;
 636     }
 637 }
 638
 639 /* Either we drop the packet or we send a reply to the sender. */
 640 typedef enum {
 641   ARP_INPUT_NEXT_DROP,
 642   ARP_INPUT_NEXT_REPLY_TX,
 643   ARP_INPUT_N_NEXT,
 644 } arp_input_next_t;
 645
 646 #define foreach_ethernet_arp_error                                      \
 647   _ (replies_sent, "ARP replies sent")                                  \
 648   _ (l2_type_not_ethernet, "L2 type not ethernet")                      \
 649   _ (l3_type_not_ip4, "L3 type not IP4")                                \
 650   _ (l3_src_address_not_local, "IP4 source address not local to subnet") \
 651   _ (l3_dst_address_not_local, "IP4 destination address not local to subnet") \
 652   _ (l3_src_address_is_local, "IP4 source address matches local interface") \
 653   _ (l3_src_address_learned, "ARP request IP4 source address learned")  \
 654   _ (replies_received, "ARP replies received")                          \
 655   _ (opcode_not_request, "ARP opcode not request")                      \
 656   _ (proxy_arp_replies_sent, "Proxy ARP replies sent")                  \
 657   _ (l2_address_mismatch, "ARP hw addr does not match L2 frame src addr") \
 658   _ (missing_interface_address, "ARP missing interface address") \
 659   _ (gratuitous_arp, "ARP probe or announcement dropped") \
 660
 661 typedef enum {
 662 #define _(sym,string) ETHERNET_ARP_ERROR_##sym,
 663   foreach_ethernet_arp_error
 664 #undef _
 665   ETHERNET_ARP_N_ERROR,
 666 } ethernet_arp_input_error_t;
 667
 668 /* get first interface address */
 669 ip4_address_t *
 670 ip4_interface_first_address (ip4_main_t * im, u32 sw_if_index,
 671                              ip_interface_address_t ** result_ia)
 672 {
 673   ip_lookup_main_t * lm = &im->lookup_main;
 674   ip_interface_address_t * ia = 0;
 675   ip4_address_t * result = 0;
 676
 677   foreach_ip_interface_address (lm, ia, sw_if_index,
 678                                 1 /* honor unnumbered */,
 679   ({
 680     ip4_address_t * a = ip_interface_address_get_address (lm, ia);
 681     result = a;
 682     break;
 683   }));
 684   if (result_ia)
 685     *result_ia = result ? ia : 0;
 686   return result;
 687 }
 688
 689 static void unset_random_arp_entry (void)
 690 {
 691   ethernet_arp_main_t * am = &ethernet_arp_main;
 692   ethernet_arp_ip4_entry_t * e;
 693   vnet_main_t * vnm = vnet_get_main();
 694   ethernet_arp_ip4_over_ethernet_address_t delme;
 695   u32 index;
 696
 697   index = pool_next_index (am->ip4_entry_pool, am->arp_delete_rotor);
 698   am->arp_delete_rotor = index;
 699
 700   /* Try again from elt 0, could happen if an intfc goes down */
 701   if (index == ~0)
 702     {
 703       index = pool_next_index (am->ip4_entry_pool, am->arp_delete_rotor);
 704       am->arp_delete_rotor = index;
 705     }
 706
 707   /* Nothing left in the pool */
 708   if (index == ~0)
 709     return;
 710
 711   e = pool_elt_at_index (am->ip4_entry_pool, index);
 712
 713   clib_memcpy (&delme.ethernet, e->ethernet_address, 6);
 714   delme.ip4.as_u32 = e->key.ip4_address.as_u32;
 715
 716   vnet_arp_unset_ip4_over_ethernet (vnm, e->key.sw_if_index,
 717                                     e->key.fib_index, &delme);
 718 }
 719
 720 static void arp_unnumbered (vlib_buffer_t * p0,
 721                        u32 pi0,
 722                        ethernet_header_t * eth0,
 723                        ip_interface_address_t * ifa0)
 724 {
 725   vlib_main_t * vm = vlib_get_main();
 726   vnet_main_t * vnm = vnet_get_main();
 727   vnet_interface_main_t * vim = &vnm->interface_main;
 728   vnet_sw_interface_t * si;
 729   vnet_hw_interface_t * hi;
 730   u32 unnum_src_sw_if_index;
 731   u32 * broadcast_swifs = 0;
 732   u32 * buffers = 0;
 733   u32 n_alloc = 0;
 734   vlib_buffer_t * b0;
 735   int i;
 736   u8 dst_mac_address[6];
 737   i16 header_size;
 738   ethernet_arp_header_t * arp0;
 739
 740   /* Save the dst mac address */
 741   clib_memcpy(dst_mac_address, eth0->dst_address, sizeof (dst_mac_address));
 742
 743   /* Figure out which sw_if_index supplied the address */
 744   unnum_src_sw_if_index = ifa0->sw_if_index;
 745
 746   /* Track down all users of the unnumbered source */
 747   pool_foreach (si, vim->sw_interfaces,
 748   ({
 749     if (si->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED &&
 750         (si->unnumbered_sw_if_index == unnum_src_sw_if_index))
 751       {
 752         vec_add1 (broadcast_swifs, si->sw_if_index);
 753       }
 754   }));
 755
 756
 757   ASSERT (vec_len(broadcast_swifs));
 758
 759   /* Allocate buffering if we need it */
 760   if (vec_len(broadcast_swifs) > 1)
 761     {
 762       vec_validate (buffers, vec_len(broadcast_swifs)-2);
 763       n_alloc = vlib_buffer_alloc (vm, buffers, vec_len(buffers));
 764       _vec_len (buffers) = n_alloc;
 765       for (i = 0; i < n_alloc; i++)
 766         {
 767           b0 = vlib_get_buffer (vm, buffers[i]);
 768
 769           /* xerox (partially built) ARP pkt */
 770           clib_memcpy (b0->data, p0->data, p0->current_length + p0->current_data);
 771           b0->current_data = p0->current_data;
 772           b0->current_length = p0->current_length;
 773           vnet_buffer(b0)->sw_if_index[VLIB_RX] =
 774             vnet_buffer(p0)->sw_if_index[VLIB_RX];
 775         }
 776     }
 777
 778   vec_insert (buffers, 1, 0);
 779   buffers[0] = pi0;
 780
 781   for (i = 0; i < vec_len(buffers); i++)
 782     {
 783       b0 = vlib_get_buffer(vm, buffers[i]);
 784       arp0 = vlib_buffer_get_current (b0);
 785
 786       hi = vnet_get_sup_hw_interface (vnm, broadcast_swifs[i]);
 787       si = vnet_get_sw_interface (vnm, broadcast_swifs[i]);
 788
 789       /* For decoration, most likely */
 790       vnet_buffer(b0)->sw_if_index[VLIB_TX] = hi->sw_if_index;
 791
 792       /* Fix ARP pkt src address */
 793       clib_memcpy (arp0->ip4_over_ethernet[0].ethernet, hi->hw_address, 6);
 794
 795       /* Build L2 encaps for this swif */
 796       header_size = sizeof (ethernet_header_t);
 797       if (si->sub.eth.flags.one_tag)
 798         header_size += 4;
 799       else if (si->sub.eth.flags.two_tags)
 800         header_size += 8;
 801
 802       vlib_buffer_advance (b0, -header_size);
 803       eth0 = vlib_buffer_get_current (b0);
 804
 805       if (si->sub.eth.flags.one_tag) {
 806         ethernet_vlan_header_t * outer = (void *) (eth0 + 1);
 807
 808         eth0->type = si->sub.eth.flags.dot1ad ?
 809           clib_host_to_net_u16 (ETHERNET_TYPE_DOT1AD) :
 810           clib_host_to_net_u16 (ETHERNET_TYPE_VLAN);
 811         outer->priority_cfi_and_id =
 812           clib_host_to_net_u16 (si->sub.eth.outer_vlan_id);
 813         outer->type = clib_host_to_net_u16 (ETHERNET_TYPE_ARP);
 814
 815       } else if (si->sub.eth.flags.two_tags) {
 816         ethernet_vlan_header_t * outer = (void *) (eth0 + 1);
 817         ethernet_vlan_header_t * inner = (void *) (outer + 1);
 818
 819         eth0->type = si->sub.eth.flags.dot1ad ?
 820           clib_host_to_net_u16 (ETHERNET_TYPE_DOT1AD) :
 821           clib_host_to_net_u16 (ETHERNET_TYPE_VLAN);
 822         outer->priority_cfi_and_id =
 823           clib_host_to_net_u16 (si->sub.eth.outer_vlan_id);
 824         outer->type = clib_host_to_net_u16 (ETHERNET_TYPE_VLAN);
 825         inner->priority_cfi_and_id =
 826           clib_host_to_net_u16 (si->sub.eth.inner_vlan_id);
 827         inner->type = clib_host_to_net_u16 (ETHERNET_TYPE_ARP);
 828
 829       } else {
 830         eth0->type = clib_host_to_net_u16 (ETHERNET_TYPE_ARP);
 831       }
 832
 833       /* Restore the original dst address, set src address */
 834       clib_memcpy (eth0->dst_address, dst_mac_address, sizeof (eth0->dst_address));
 835       clib_memcpy (eth0->src_address, hi->hw_address, sizeof (eth0->src_address));
 836
 837       /* Transmit replicas */
 838       if (i > 0)
 839         {
 840           vlib_frame_t * f = vlib_get_frame_to_node (vm, hi->output_node_index);
 841           u32 * to_next = vlib_frame_vector_args (f);
 842           to_next[0] = buffers[i];
 843           f->n_vectors = 1;
 844           vlib_put_frame_to_node (vm, hi->output_node_index, f);
 845         }
 846     }
 847
 848   /* The regular path outputs the original pkt.. */
 849   vnet_buffer (p0)->sw_if_index[VLIB_TX] = broadcast_swifs[0];
 850
 851   vec_free (broadcast_swifs);
 852   vec_free (buffers);
 853 }
 854
 855 static uword
 856 arp_input (vlib_main_t * vm,
 857            vlib_node_runtime_t * node,
 858            vlib_frame_t * frame)
 859 {
 860   ethernet_arp_main_t * am = &ethernet_arp_main;
 861   vnet_main_t * vnm = vnet_get_main();
 862   ip4_main_t * im4 = &ip4_main;
 863   u32 n_left_from, next_index, * from, * to_next;
 864   u32 n_replies_sent = 0, n_proxy_arp_replies_sent = 0;
 865
 866   from = vlib_frame_vector_args (frame);
 867   n_left_from = frame->n_vectors;
 868   next_index = node->cached_next_index;
 869
 870   if (node->flags & VLIB_NODE_FLAG_TRACE)
 871     vlib_trace_frame_buffers_only (vm, node, from, frame->n_vectors,
 872                                    /* stride */ 1,
 873                                    sizeof (ethernet_arp_input_trace_t));
 874
 875   while (n_left_from > 0)
 876     {
 877       u32 n_left_to_next;
 878
 879       vlib_get_next_frame (vm, node, next_index,
 880                            to_next, n_left_to_next);
 881
 882       while (n_left_from > 0 && n_left_to_next > 0)
 883         {
 884           vlib_buffer_t * p0;
 885           vnet_hw_interface_t * hw_if0;
 886           ethernet_arp_header_t * arp0;
 887           ethernet_header_t * eth0;
 888           ip_interface_address_t * ifa0;
 889           ip_adjacency_t * adj0;
 890           ip4_address_t * if_addr0;
 891           ip4_address_t proxy_src;
 892           u32 pi0, error0, next0, sw_if_index0;
 893           u8 is_request0, src_is_local0, dst_is_local0, is_unnum0;
 894           ethernet_proxy_arp_t * pa;
 895
 896           pi0 = from[0];
 897           to_next[0] = pi0;
 898           from += 1;
 899           to_next += 1;
 900           n_left_from -= 1;
 901           n_left_to_next -= 1;
 902
 903           p0 = vlib_get_buffer (vm, pi0);
 904           arp0 = vlib_buffer_get_current (p0);
 905
 906           is_request0 = arp0->opcode
 907               == clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_request);
 908
 909           error0 = ETHERNET_ARP_ERROR_replies_sent;
 910
 911           error0 = (arp0->l2_type != clib_net_to_host_u16 (ETHERNET_ARP_HARDWARE_TYPE_ethernet)
 912                     ? ETHERNET_ARP_ERROR_l2_type_not_ethernet
 913                     : error0);
 914           error0 = (arp0->l3_type != clib_net_to_host_u16 (ETHERNET_TYPE_IP4)
 915                     ? ETHERNET_ARP_ERROR_l3_type_not_ip4
 916                     : error0);
 917
 918           sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX];
 919
 920           if (error0)
 921             goto drop1;
 922
 923           /* Check that IP address is local and matches incoming interface. */
 924           if_addr0 = ip4_interface_address_matching_destination (im4,
 925                                                                  &arp0->ip4_over_ethernet[1].ip4,
 926                                                                  sw_if_index0,
 927                                                                  &ifa0);
 928           if (! if_addr0)
 929             {
 930               error0 = ETHERNET_ARP_ERROR_l3_dst_address_not_local;
 931               goto drop1;
 932             }
 933
 934           /* Honor unnumbered interface, if any */
 935           is_unnum0 = sw_if_index0 != ifa0->sw_if_index;
 936
 937           /* Source must also be local to subnet of matching interface address. */
 938           if (! ip4_destination_matches_interface (im4, &arp0->ip4_over_ethernet[0].ip4, ifa0))
 939             {
 940               error0 = ETHERNET_ARP_ERROR_l3_src_address_not_local;
 941               goto drop1;
 942             }
 943
 944           /* Reject requests/replies with our local interface address. */
 945           src_is_local0 = if_addr0->as_u32 == arp0->ip4_over_ethernet[0].ip4.as_u32;
 946           if (src_is_local0)
 947             {
 948               error0 = ETHERNET_ARP_ERROR_l3_src_address_is_local;
 949               goto drop1;
 950             }
 951
 952           dst_is_local0 = if_addr0->as_u32 == arp0->ip4_over_ethernet[1].ip4.as_u32;
 953
 954           /* Fill in ethernet header. */
 955           eth0 = ethernet_buffer_get_header (p0);
 956
 957           /* Trash ARP packets whose ARP-level source addresses do not
 958              match their L2-frame-level source addresses */
 959           if (memcmp (eth0->src_address, arp0->ip4_over_ethernet[0].ethernet,
 960                       sizeof (eth0->src_address)))
 961             {
 962               error0 = ETHERNET_ARP_ERROR_l2_address_mismatch;
 963               goto drop2;
 964             }
 965
 966           /* Learn or update sender's mapping only for requests or unicasts
 967              that don't match local interface address. */
 968           if (ethernet_address_cast (eth0->dst_address) == ETHERNET_ADDRESS_UNICAST
 969               || is_request0)
 970             {
 971               if (am->limit_arp_cache_size &&
 972                   pool_elts (am->ip4_entry_pool) >= am->limit_arp_cache_size)
 973                 unset_random_arp_entry();
 974
 975               vnet_arp_set_ip4_over_ethernet (vnm, sw_if_index0,
 976                                               (u32)~0 /* default fib */,
 977                                               &arp0->ip4_over_ethernet[0],
 978                                               0 /* is_static */);
 979               error0 = ETHERNET_ARP_ERROR_l3_src_address_learned;
 980              }
 981
 982           /* Only send a reply for requests sent which match a local interface. */
 983           if (! (is_request0 && dst_is_local0))
 984             {
 985               error0 = (arp0->opcode == clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply)
 986                         ? ETHERNET_ARP_ERROR_replies_received : error0);
 987               goto drop1;
 988             }
 989
 990           /* Send a reply. */
 991         send_reply:
 992           vnet_buffer (p0)->sw_if_index[VLIB_TX] = sw_if_index0;
 993           hw_if0 = vnet_get_sup_hw_interface (vnm, sw_if_index0);
 994
 995           /* Send reply back through input interface */
 996           vnet_buffer (p0)->sw_if_index[VLIB_TX] = sw_if_index0;
 997           next0 = ARP_INPUT_NEXT_REPLY_TX;
 998
 999           arp0->opcode = clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply);
1000
1001           arp0->ip4_over_ethernet[1] = arp0->ip4_over_ethernet[0];
1002
1003           clib_memcpy (arp0->ip4_over_ethernet[0].ethernet, hw_if0->hw_address, 6);
1004           clib_mem_unaligned (&arp0->ip4_over_ethernet[0].ip4.data_u32, u32) = if_addr0->data_u32;
1005
1006           /* Hardware must be ethernet-like. */
1007           ASSERT (vec_len (hw_if0->hw_address) == 6);
1008
1009           clib_memcpy (eth0->dst_address, eth0->src_address, 6);
1010           clib_memcpy (eth0->src_address, hw_if0->hw_address, 6);
1011
1012           /* Figure out how much to rewind current data from adjacency. */
1013           if (ifa0)
1014             {
1015               adj0 = ip_get_adjacency (&ip4_main.lookup_main,
1016                                        ifa0->neighbor_probe_adj_index);
1017               if (adj0->lookup_next_index != IP_LOOKUP_NEXT_ARP)
1018                 {
1019                   error0 = ETHERNET_ARP_ERROR_missing_interface_address;
1020                   goto drop2;
1021                 }
1022               if (is_unnum0)
1023                 arp_unnumbered (p0, pi0, eth0, ifa0);
1024               else
1025                 vlib_buffer_advance (p0, -adj0->rewrite_header.data_bytes);
1026             }
1027
1028           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,to_next,
1029                                            n_left_to_next,pi0,next0);
1030
1031           n_replies_sent += 1;
1032           continue;
1033
1034         drop1:
1035           if (0 == arp0->ip4_over_ethernet[0].ip4.as_u32 ||
1036               (arp0->ip4_over_ethernet[0].ip4.as_u32 ==
1037                arp0->ip4_over_ethernet[1].ip4.as_u32))
1038             {
1039               error0 = ETHERNET_ARP_ERROR_gratuitous_arp;
1040               goto drop2;
1041             }
1042           /* See if proxy arp is configured for the address */
1043           if (is_request0)
1044             {
1045               vnet_sw_interface_t * si;
1046               u32 this_addr = clib_net_to_host_u32
1047                 (arp0->ip4_over_ethernet[1].ip4.as_u32);
1048               u32 fib_index0;
1049
1050               si = vnet_get_sw_interface (vnm, sw_if_index0);
1051
1052               if (!(si->flags & VNET_SW_INTERFACE_FLAG_PROXY_ARP))
1053                 goto drop2;
1054
1055               fib_index0 = vec_elt (im4->fib_index_by_sw_if_index,
1056                                     sw_if_index0);
1057
1058               vec_foreach (pa, am->proxy_arps)
1059                 {
1060                   u32 lo_addr = clib_net_to_host_u32 (pa->lo_addr);
1061                   u32 hi_addr = clib_net_to_host_u32 (pa->hi_addr);
1062
1063                    /* an ARP request hit in the proxy-arp table? */
1064                    if ((this_addr >= lo_addr && this_addr <= hi_addr) &&
1065                        (fib_index0 == pa->fib_index))
1066                     {
1067                       eth0 = ethernet_buffer_get_header (p0);
1068                       proxy_src.as_u32 =
1069                         arp0->ip4_over_ethernet[1].ip4.data_u32;
1070
1071                       /*
1072                        * Rewind buffer, direct code above not to
1073                        * think too hard about it.
1074                        * $$$ is the answer ever anything other than
1075                        * vlib_buffer_reset(..)?
1076                        */
1077                       ifa0 = 0;
1078                       if_addr0 = &proxy_src;
1079                       vlib_buffer_reset (p0);
1080                       n_proxy_arp_replies_sent++;
1081                       goto send_reply;
1082                     }
1083                 }
1084             }
1085
1086         drop2:
1087
1088           next0 = ARP_INPUT_NEXT_DROP;
1089           p0->error = node->errors[error0];
1090
1091           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,to_next,
1092                                            n_left_to_next,pi0,next0);
1093         }
1094
1095       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1096     }
1097
1098   vlib_error_count (vm, node->node_index,
1099                     ETHERNET_ARP_ERROR_replies_sent,
1100                     n_replies_sent - n_proxy_arp_replies_sent);
1101
1102   vlib_error_count (vm, node->node_index,
1103                     ETHERNET_ARP_ERROR_proxy_arp_replies_sent,
1104                     n_proxy_arp_replies_sent);
1105   return frame->n_vectors;
1106 }
1107
1108 static char * ethernet_arp_error_strings[] = {
1109 #define _(sym,string) string,
1110   foreach_ethernet_arp_error
1111 #undef _
1112 };
1113
1114 VLIB_REGISTER_NODE (arp_input_node,static) = {
1115   .function = arp_input,
1116   .name = "arp-input",
1117   .vector_size = sizeof (u32),
1118
1119   .n_errors = ETHERNET_ARP_N_ERROR,
1120   .error_strings = ethernet_arp_error_strings,
1121
1122   .n_next_nodes = ARP_INPUT_N_NEXT,
1123   .next_nodes = {
1124     [ARP_INPUT_NEXT_DROP] = "error-drop",
1125     [ARP_INPUT_NEXT_REPLY_TX] = "interface-output",
1126   },
1127
1128   .format_buffer = format_ethernet_arp_header,
1129   .format_trace = format_ethernet_arp_input_trace,
1130 };
1131
1132 static int
1133 ip4_arp_entry_sort (void *a1, void *a2)
1134 {
1135   ethernet_arp_ip4_entry_t * e1 = a1;
1136   ethernet_arp_ip4_entry_t * e2 = a2;
1137
1138   int cmp;
1139   vnet_main_t * vnm = vnet_get_main();
1140
1141   cmp = vnet_sw_interface_compare
1142     (vnm, e1->key.sw_if_index, e2->key.sw_if_index);
1143   if (! cmp)
1144     cmp = ip4_address_compare (&e1->key.ip4_address, &e2->key.ip4_address);
1145   return cmp;
1146 }
1147
1148 static clib_error_t *
1149 show_ip4_arp (vlib_main_t * vm,
1150               unformat_input_t * input,
1151               vlib_cli_command_t * cmd)
1152 {
1153   vnet_main_t * vnm = vnet_get_main();
1154   ethernet_arp_main_t * am = &ethernet_arp_main;
1155   ethernet_arp_ip4_entry_t * e, * es;
1156   ethernet_proxy_arp_t * pa;
1157   clib_error_t * error = 0;
1158   u32 sw_if_index;
1159
1160   /* Filter entries by interface if given. */
1161   sw_if_index = ~0;
1162   (void) unformat_user (input, unformat_vnet_sw_interface, vnm, &sw_if_index);
1163
1164   es = 0;
1165   pool_foreach (e, am->ip4_entry_pool, ({ vec_add1 (es, e[0]); }));
1166   if ( es )
1167     {
1168       vec_sort_with_function (es, ip4_arp_entry_sort);
1169       vlib_cli_output (vm, "%U", format_ethernet_arp_ip4_entry, vnm, 0);
1170       vec_foreach (e, es) {
1171         if (sw_if_index != ~0 && e->key.sw_if_index != sw_if_index)
1172           continue;
1173         vlib_cli_output (vm, "%U", format_ethernet_arp_ip4_entry, vnm, e);
1174       }
1175       vec_free (es);
1176     }
1177
1178   if (vec_len (am->proxy_arps))
1179     {
1180       vlib_cli_output (vm, "Proxy arps enabled for:");
1181       vec_foreach(pa, am->proxy_arps)
1182         {
1183           vlib_cli_output (vm, "Fib_index %d   %U - %U ",
1184                            pa->fib_index,
1185                            format_ip4_address, &pa->lo_addr,
1186                            format_ip4_address, &pa->hi_addr);
1187         }
1188     }
1189
1190   return error;
1191 }
1192
1193 VLIB_CLI_COMMAND (show_ip4_arp_command, static) = {
1194   .path = "show ip arp",
1195   .function = show_ip4_arp,
1196   .short_help = "Show ARP table",
1197 };
1198
1199 typedef struct {
1200   pg_edit_t l2_type, l3_type;
1201   pg_edit_t n_l2_address_bytes, n_l3_address_bytes;
1202   pg_edit_t opcode;
1203   struct {
1204     pg_edit_t ethernet;
1205     pg_edit_t ip4;
1206   } ip4_over_ethernet[2];
1207 } pg_ethernet_arp_header_t;
1208
1209 static inline void
1210 pg_ethernet_arp_header_init (pg_ethernet_arp_header_t * p)
1211 {
1212   /* Initialize fields that are not bit fields in the IP header. */
1213 #define _(f) pg_edit_init (&p->f, ethernet_arp_header_t, f);
1214   _ (l2_type);
1215   _ (l3_type);
1216   _ (n_l2_address_bytes);
1217   _ (n_l3_address_bytes);
1218   _ (opcode);
1219   _ (ip4_over_ethernet[0].ethernet);
1220   _ (ip4_over_ethernet[0].ip4);
1221   _ (ip4_over_ethernet[1].ethernet);
1222   _ (ip4_over_ethernet[1].ip4);
1223 #undef _
1224 }
1225
1226 uword
1227 unformat_pg_arp_header (unformat_input_t * input, va_list * args)
1228 {
1229   pg_stream_t * s = va_arg (*args, pg_stream_t *);
1230   pg_ethernet_arp_header_t * p;
1231   u32 group_index;
1232
1233   p = pg_create_edit_group (s, sizeof (p[0]), sizeof (ethernet_arp_header_t),
1234                             &group_index);
1235   pg_ethernet_arp_header_init (p);
1236
1237   /* Defaults. */
1238   pg_edit_set_fixed (&p->l2_type, ETHERNET_ARP_HARDWARE_TYPE_ethernet);
1239   pg_edit_set_fixed (&p->l3_type, ETHERNET_TYPE_IP4);
1240   pg_edit_set_fixed (&p->n_l2_address_bytes, 6);
1241   pg_edit_set_fixed (&p->n_l3_address_bytes, 4);
1242
1243   if (! unformat (input, "%U: %U/%U -> %U/%U",
1244                   unformat_pg_edit,
1245                   unformat_ethernet_arp_opcode_net_byte_order, &p->opcode,
1246                   unformat_pg_edit,
1247                   unformat_ethernet_address, &p->ip4_over_ethernet[0].ethernet,
1248                   unformat_pg_edit,
1249                   unformat_ip4_address, &p->ip4_over_ethernet[0].ip4,
1250                   unformat_pg_edit,
1251                   unformat_ethernet_address, &p->ip4_over_ethernet[1].ethernet,
1252                   unformat_pg_edit,
1253                   unformat_ip4_address, &p->ip4_over_ethernet[1].ip4))
1254     {
1255       /* Free up any edits we may have added. */
1256       pg_free_edit_group (s);
1257       return 0;
1258     }
1259   return 1;
1260 }
1261
1262 clib_error_t *ip4_set_arp_limit (u32 arp_limit)
1263 {
1264   ethernet_arp_main_t * am = &ethernet_arp_main;
1265
1266   am->limit_arp_cache_size = arp_limit;
1267   return 0;
1268 }
1269
1270 static void
1271 arp_ip4_entry_del_adj(ethernet_arp_ip4_entry_t *e, u32 adj_index)
1272 {
1273   int done = 0;
1274   int i;
1275
1276   while (!done)
1277     {
1278       vec_foreach_index(i, e->adjacencies)
1279         if (vec_elt(e->adjacencies, i) == adj_index)
1280           {
1281             vec_del1(e->adjacencies, i);
1282             continue;
1283           }
1284       done = 1;
1285     }
1286 }
1287
1288 static void
1289 arp_ip4_entry_add_adj(ethernet_arp_ip4_entry_t *e, u32 adj_index)
1290 {
1291   int i;
1292   vec_foreach_index(i, e->adjacencies)
1293     if (vec_elt(e->adjacencies, i) == adj_index)
1294       return;
1295   vec_add1(e->adjacencies, adj_index);
1296 }
1297
1298 static void
1299 arp_add_del_adj_cb (struct ip_lookup_main_t * lm,
1300                     u32 adj_index,
1301                     ip_adjacency_t * adj,
1302                     u32 is_del)
1303 {
1304   ethernet_arp_main_t * am = &ethernet_arp_main;
1305   ip4_main_t * im = &ip4_main;
1306   ethernet_arp_ip4_key_t k;
1307   ethernet_arp_ip4_entry_t * e = 0;
1308   uword * p;
1309   u32 ai;
1310
1311   for(ai = adj->heap_handle; ai < adj->heap_handle + adj->n_adj ; ai++)
1312     {
1313       adj = ip_get_adjacency (lm, ai);
1314       if (adj->lookup_next_index == IP_LOOKUP_NEXT_ARP && adj->arp.next_hop.ip4.as_u32)
1315         {
1316           k.sw_if_index = adj->rewrite_header.sw_if_index;
1317           k.ip4_address.as_u32 = adj->arp.next_hop.ip4.as_u32;
1318           k.fib_index = im->fib_index_by_sw_if_index[adj->rewrite_header.sw_if_index];
1319           p = mhash_get (&am->ip4_entry_by_key, &k);
1320           if (p)
1321             e = pool_elt_at_index (am->ip4_entry_pool, p[0]);
1322         }
1323       else
1324         continue;
1325
1326       if (is_del)
1327         {
1328           if (!e)
1329             clib_warning("Adjacency contains unknown ARP next hop %U (del)",
1330                          format_ip46_address, &adj->arp.next_hop, IP46_TYPE_IP4);
1331           else
1332             arp_ip4_entry_del_adj(e, adj->heap_handle);
1333         }
1334       else /* add */
1335         {
1336           if (!e)
1337             clib_warning("Adjacency contains unknown ARP next hop %U (add)",
1338                          format_ip46_address, &adj->arp.next_hop, IP46_TYPE_IP4);
1339           else
1340             arp_ip4_entry_add_adj(e, adj->heap_handle);
1341         }
1342     }
1343 }
1344
1345 static clib_error_t * ethernet_arp_init (vlib_main_t * vm)
1346 {
1347   ethernet_arp_main_t * am = &ethernet_arp_main;
1348   pg_node_t * pn;
1349   clib_error_t * error;
1350   ip4_main_t * im = &ip4_main;
1351   ip_lookup_main_t * lm = &im->lookup_main;
1352
1353   if ((error = vlib_call_init_function (vm, ethernet_init)))
1354     return error;
1355
1356   ethernet_register_input_type (vm, ETHERNET_TYPE_ARP, arp_input_node.index);
1357
1358   pn = pg_get_node (arp_input_node.index);
1359   pn->unformat_edit = unformat_pg_arp_header;
1360
1361   am->opcode_by_name = hash_create_string (0, sizeof (uword));
1362 #define _(o) hash_set_mem (am->opcode_by_name, #o, ETHERNET_ARP_OPCODE_##o);
1363   foreach_ethernet_arp_opcode;
1364 #undef _
1365
1366   mhash_init (&am->ip4_entry_by_key,
1367               /* value size */ sizeof (uword),
1368               /* key size */ sizeof (ethernet_arp_ip4_key_t));
1369
1370   /* $$$ configurable */
1371   am->limit_arp_cache_size = 50000;
1372
1373   am->pending_resolutions_by_address = hash_create (0, sizeof (uword));
1374   am->mac_changes_by_address = hash_create (0, sizeof (uword));
1375
1376   /* don't trace ARP error packets */
1377   {
1378     vlib_node_runtime_t *rt =
1379       vlib_node_get_runtime (vm, arp_input_node.index);
1380
1381 #define _(a,b)                                  \
1382     vnet_pcap_drop_trace_filter_add_del         \
1383         (rt->errors[ETHERNET_ARP_ERROR_##a],    \
1384          1 /* is_add */);
1385     foreach_ethernet_arp_error
1386 #undef _
1387   }
1388
1389   ip_register_add_del_adjacency_callback(lm, arp_add_del_adj_cb);
1390
1391   return 0;
1392 }
1393
1394 VLIB_INIT_FUNCTION (ethernet_arp_init);
1395
1396 int
1397 vnet_arp_unset_ip4_over_ethernet (vnet_main_t * vnm,
1398                                   u32 sw_if_index, u32 fib_index,
1399                                   void * a_arg)
1400 {
1401   ethernet_arp_ip4_over_ethernet_address_t * a = a_arg;
1402   vnet_arp_set_ip4_over_ethernet_rpc_args_t args;
1403
1404   args.sw_if_index = sw_if_index;
1405   args.fib_index = fib_index;
1406   args.is_remove = 1;
1407   clib_memcpy (&args.a, a, sizeof (*a));
1408
1409   vl_api_rpc_call_main_thread (set_ip4_over_ethernet_rpc_callback,
1410                                (u8 *) &args, sizeof (args));
1411   return 0;
1412 }
1413
1414 static inline int
1415 vnet_arp_unset_ip4_over_ethernet_internal (vnet_main_t * vnm,
1416                                            u32 sw_if_index,
1417                                            u32 fib_index,
1418                                            void * a_arg)
1419 {
1420   ethernet_arp_ip4_entry_t * e;
1421   ethernet_arp_main_t * am = &ethernet_arp_main;
1422   ethernet_arp_ip4_over_ethernet_address_t * a = a_arg;
1423   ethernet_arp_ip4_key_t k;
1424   uword * p;
1425   ip4_add_del_route_args_t args;
1426   ip4_main_t * im = &ip4_main;
1427   ip_lookup_main_t * lm = &im->lookup_main;
1428   u32 adj_index;
1429   ip_adjacency_t * adj;
1430
1431   k.sw_if_index = sw_if_index;
1432   k.ip4_address = a->ip4;
1433   k.fib_index = fib_index;
1434   p = mhash_get (&am->ip4_entry_by_key, &k);
1435   if (! p)
1436     return -1;
1437
1438   memset(&args, 0, sizeof(args));
1439
1440   /*
1441    * Make sure that the route actually exists before we try to delete it,
1442    * and make sure that it's a rewrite adjacency.
1443    *
1444    * If we point 1-N unnumbered interfaces at a loopback interface and
1445    * shut down the loopback before shutting down 1-N unnumbered
1446    * interfaces, the ARP cache will still have an entry,
1447    * but the route will have disappeared.
1448    *
1449    * See also ip4_del_interface_routes (...)
1450    *            -> ip4_delete_matching_routes (...).
1451    */
1452
1453   adj_index = ip4_fib_lookup_with_table
1454       (im, fib_index, &a->ip4, 1 /* disable default route */);
1455
1456   /* Miss adj? Forget it... */
1457   if (adj_index != lm->miss_adj_index) {
1458       adj = ip_get_adjacency (lm, adj_index);
1459       /*
1460        * Stupid control-plane trick:
1461        * admin down an interface (removes arp routes from fib),
1462        * bring the interface back up (does not reinstall them)
1463        * then remove the arp cache entry (yuck). When that happens,
1464        * the adj we find here will be the interface subnet ARP adj.
1465        */
1466       if (adj->lookup_next_index == IP_LOOKUP_NEXT_REWRITE) {
1467           args.table_index_or_table_id = fib_index;
1468           args.flags = IP4_ROUTE_FLAG_FIB_INDEX | IP4_ROUTE_FLAG_DEL
1469               | IP4_ROUTE_FLAG_NEIGHBOR;
1470           args.dst_address = a->ip4;
1471           args.dst_address_length = 32;
1472           ip4_add_del_route (im, &args);
1473           ip4_maybe_remap_adjacencies (im, fib_index, args.flags);
1474       }
1475   }
1476
1477   e = pool_elt_at_index (am->ip4_entry_pool, p[0]);
1478   mhash_unset (&am->ip4_entry_by_key, &e->key, 0);
1479   pool_put (am->ip4_entry_pool, e);
1480   return 0;
1481 }
1482
1483 static void
1484 increment_ip4_and_mac_address (ethernet_arp_ip4_over_ethernet_address_t *a)
1485 {
1486   u8 old;
1487   int i;
1488
1489   for (i = 3; i >= 0; i--)
1490     {
1491       old = a->ip4.as_u8[i];
1492       a->ip4.as_u8[i] += 1;
1493       if (old < a->ip4.as_u8[i])
1494         break;
1495     }
1496
1497   for (i = 5; i >= 0; i--)
1498     {
1499       old = a->ethernet[i];
1500       a->ethernet[i] += 1;
1501       if (old < a->ethernet[i])
1502         break;
1503     }
1504 }
1505
1506 int vnet_proxy_arp_add_del (ip4_address_t *lo_addr,
1507                             ip4_address_t *hi_addr,
1508                             u32 fib_index, int is_del)
1509 {
1510   ethernet_arp_main_t *am = &ethernet_arp_main;
1511   ethernet_proxy_arp_t *pa;
1512   u32 found_at_index = ~0;
1513
1514   vec_foreach (pa, am->proxy_arps)
1515     {
1516       if (pa->lo_addr == lo_addr->as_u32
1517           && pa->hi_addr == hi_addr->as_u32
1518           && pa->fib_index == fib_index)
1519         {
1520           found_at_index = pa - am->proxy_arps;
1521           break;
1522         }
1523     }
1524
1525   if (found_at_index != ~0)
1526     {
1527       /* Delete, otherwise it's already in the table */
1528       if (is_del)
1529         vec_delete (am->proxy_arps, 1, found_at_index);
1530       return 0;
1531     }
1532   /* delete, no such entry */
1533   if (is_del)
1534     return VNET_API_ERROR_NO_SUCH_ENTRY;
1535
1536   /* add, not in table */
1537   vec_add2 (am->proxy_arps, pa, 1);
1538   pa->lo_addr = lo_addr->as_u32;
1539   pa->hi_addr = hi_addr->as_u32;
1540   pa->fib_index = fib_index;
1541   return 0;
1542 }
1543
1544 /*
1545  * Remove any proxy arp entries asdociated with the
1546  * specificed fib.
1547  */
1548 int vnet_proxy_arp_fib_reset (u32 fib_id)
1549 {
1550   ip4_main_t * im = &ip4_main;
1551   ethernet_arp_main_t *am = &ethernet_arp_main;
1552   ethernet_proxy_arp_t *pa;
1553   u32 * entries_to_delete = 0;
1554   u32 fib_index;
1555   uword * p;
1556   int i;
1557
1558   p = hash_get (im->fib_index_by_table_id, fib_id);
1559   if (! p)
1560       return VNET_API_ERROR_NO_SUCH_ENTRY;
1561   fib_index = p[0];
1562
1563   vec_foreach (pa, am->proxy_arps)
1564     {
1565       if (pa->fib_index == fib_index)
1566         {
1567           vec_add1 (entries_to_delete, pa - am->proxy_arps);
1568         }
1569     }
1570
1571   for (i = 0; i < vec_len(entries_to_delete); i++)
1572     {
1573        vec_delete (am->proxy_arps, 1, entries_to_delete[i]);
1574     }
1575
1576   vec_free (entries_to_delete);
1577
1578    return 0;
1579 }
1580
1581 u32
1582 vnet_arp_glean_add(u32 fib_index, void * next_hop_arg)
1583 {
1584   ethernet_arp_main_t * am = &ethernet_arp_main;
1585   ip4_main_t * im = &ip4_main;
1586   ip_lookup_main_t * lm = &im->lookup_main;
1587   ip4_address_t * next_hop = next_hop_arg;
1588   ip_adjacency_t add_adj, *adj;
1589   ip4_add_del_route_args_t args;
1590   ethernet_arp_ip4_entry_t * e;
1591   ethernet_arp_ip4_key_t k;
1592   u32 adj_index;
1593
1594   adj_index = ip4_fib_lookup_with_table(im, fib_index, next_hop, 0);
1595   adj = ip_get_adjacency(lm, adj_index);
1596
1597   if (!adj || adj->lookup_next_index != IP_LOOKUP_NEXT_ARP)
1598     return ~0;
1599
1600   if (adj->arp.next_hop.ip4.as_u32 != 0)
1601     return adj_index;
1602
1603   k.sw_if_index = adj->rewrite_header.sw_if_index;
1604   k.fib_index = fib_index;
1605   k.ip4_address.as_u32 = next_hop->as_u32;
1606
1607   if (mhash_get (&am->ip4_entry_by_key, &k))
1608     return adj_index;
1609
1610   pool_get (am->ip4_entry_pool, e);
1611   mhash_set (&am->ip4_entry_by_key, &k, e - am->ip4_entry_pool, /* old value */ 0);
1612   e->key = k;
1613   e->cpu_time_last_updated = clib_cpu_time_now ();
1614   e->flags = ETHERNET_ARP_IP4_ENTRY_FLAG_GLEAN;
1615
1616   memset(&args, 0, sizeof(args));
1617   clib_memcpy(&add_adj, adj, sizeof(add_adj));
1618   ip46_address_set_ip4(&add_adj.arp.next_hop, next_hop); /* install neighbor /32 route */
1619   args.table_index_or_table_id = fib_index;
1620   args.flags = IP4_ROUTE_FLAG_FIB_INDEX | IP4_ROUTE_FLAG_ADD| IP4_ROUTE_FLAG_NEIGHBOR;
1621   args.dst_address.as_u32 = next_hop->as_u32;
1622   args.dst_address_length = 32;
1623   args.adj_index = ~0;
1624   args.add_adj = &add_adj;
1625   args.n_add_adj = 1;
1626   ip4_add_del_route (im, &args);
1627   return ip4_fib_lookup_with_table (im, fib_index, next_hop, 0);
1628 }
1629
1630 static clib_error_t *
1631 ip_arp_add_del_command_fn (vlib_main_t * vm,
1632                  unformat_input_t * input,
1633                  vlib_cli_command_t * cmd)
1634 {
1635   vnet_main_t * vnm = vnet_get_main();
1636   u32 sw_if_index;
1637   ethernet_arp_ip4_over_ethernet_address_t lo_addr, hi_addr, addr;
1638   int addr_valid = 0;
1639   int is_del = 0;
1640   int count = 1;
1641   u32 fib_index = 0;
1642   u32 fib_id;
1643   int is_static = 0;
1644   int is_proxy = 0;
1645
1646   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
1647     {
1648       /* set ip arp TenGigE1/1/0/1 1.2.3.4 aa:bb:... or aabb.ccdd... */
1649       if (unformat (input, "%U %U %U",
1650                     unformat_vnet_sw_interface, vnm, &sw_if_index,
1651                     unformat_ip4_address, &addr.ip4,
1652                     unformat_ethernet_address, &addr.ethernet))
1653         addr_valid = 1;
1654
1655       else if (unformat (input, "delete") || unformat (input, "del"))
1656         is_del = 1;
1657
1658       else if (unformat (input, "static"))
1659         is_static = 1;
1660
1661       else if (unformat (input, "count %d", &count))
1662         ;
1663
1664       else if (unformat (input, "fib-id %d", &fib_id))
1665         {
1666           ip4_main_t * im = &ip4_main;
1667           uword * p = hash_get (im->fib_index_by_table_id, fib_id);
1668           if (! p)
1669             return clib_error_return (0, "fib ID %d doesn't exist\n",
1670                                       fib_id);
1671           fib_index = p[0];
1672         }
1673
1674       else if (unformat (input, "proxy %U - %U",
1675                          unformat_ip4_address, &lo_addr.ip4,
1676                          unformat_ip4_address, &hi_addr.ip4))
1677         is_proxy = 1;
1678       else
1679         break;
1680     }
1681
1682   if (is_proxy)
1683     {
1684       (void) vnet_proxy_arp_add_del (&lo_addr.ip4, &hi_addr.ip4,
1685                                      fib_index, is_del);
1686       return 0;
1687     }
1688
1689   if (addr_valid)
1690     {
1691       int i;
1692
1693       for (i = 0; i < count; i++)
1694         {
1695           if (is_del == 0)
1696             {
1697               uword event_type, * event_data = 0;
1698
1699               /* Park the debug CLI until the arp entry is installed */
1700               vnet_register_ip4_arp_resolution_event
1701                 (vnm, &addr.ip4, vlib_current_process(vm),
1702                  1 /* type */, 0 /* data */);
1703
1704               vnet_arp_set_ip4_over_ethernet
1705                 (vnm, sw_if_index, fib_index, &addr, is_static);
1706
1707               vlib_process_wait_for_event (vm);
1708               event_type = vlib_process_get_events (vm, &event_data);
1709               vec_reset_length(event_data);
1710               if (event_type != 1)
1711                 clib_warning ("event type %d unexpected", event_type);
1712             }
1713           else
1714             vnet_arp_unset_ip4_over_ethernet
1715                 (vnm, sw_if_index, fib_index, &addr);
1716
1717           increment_ip4_and_mac_address (&addr);
1718         }
1719     }
1720   else
1721     {
1722       return clib_error_return (0, "unknown input `%U'",
1723                                 format_unformat_error, input);
1724     }
1725
1726   return 0;
1727 }
1728
1729 VLIB_CLI_COMMAND (ip_arp_add_del_command, static) = {
1730     .path = "set ip arp",
1731     .short_help = "set ip arp [del] <intfc> <ip-address> <mac-address> [static] [count <count>] [fib-id <fib-id>] [proxy <lo-addr> - <hi-addr>]",
1732     .function = ip_arp_add_del_command_fn,
1733 };
1734
1735 static clib_error_t *
1736 set_int_proxy_arp_command_fn (vlib_main_t * vm,
1737                               unformat_input_t * input,
1738                               vlib_cli_command_t * cmd)
1739 {
1740   vnet_main_t * vnm = vnet_get_main();
1741   u32 sw_if_index;
1742   vnet_sw_interface_t * si;
1743   int enable = 0;
1744   int intfc_set = 0;
1745
1746   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
1747     {
1748       if (unformat (input, "%U", unformat_vnet_sw_interface,
1749                     vnm, &sw_if_index))
1750         intfc_set = 1;
1751       else if (unformat (input, "enable") || unformat (input, "on"))
1752         enable = 1;
1753       else if (unformat (input, "disable") || unformat (input, "off"))
1754         enable = 0;
1755       else
1756         break;
1757     }
1758
1759   if (intfc_set == 0)
1760     return clib_error_return (0, "unknown input '%U'",
1761                               format_unformat_error, input);
1762
1763   si = vnet_get_sw_interface (vnm, sw_if_index);
1764   ASSERT(si);
1765   if (enable)
1766     si->flags |= VNET_SW_INTERFACE_FLAG_PROXY_ARP;
1767   else
1768     si->flags &= ~VNET_SW_INTERFACE_FLAG_PROXY_ARP;
1769
1770   return 0;
1771 }
1772
1773 VLIB_CLI_COMMAND (set_int_proxy_enable_command, static) = {
1774     .path = "set interface proxy-arp",
1775     .short_help = "set interface proxy-arp <intfc> [enable|disable]",
1776     .function = set_int_proxy_arp_command_fn,
1777 };
1778
1779
1780 /*
1781  * ARP Termination in a L2 Bridge Domain based on an
1782  * IP4 to MAC hash table mac_by_ip4 for each BD.
1783  */
1784 typedef enum {
1785   ARP_TERM_NEXT_L2_OUTPUT,
1786   ARP_TERM_NEXT_DROP,
1787   ARP_TERM_N_NEXT,
1788 } arp_term_next_t;
1789
1790 u32 arp_term_next_node_index[32];
1791
1792 static uword
1793 arp_term_l2bd (vlib_main_t * vm,
1794                vlib_node_runtime_t * node,
1795                vlib_frame_t * frame)
1796 {
1797   l2input_main_t * l2im = &l2input_main;
1798   u32 n_left_from, next_index, * from, * to_next;
1799   u32 n_replies_sent = 0;
1800   u16 last_bd_index = ~0;
1801   l2_bridge_domain_t * last_bd_config = 0;
1802   l2_input_config_t * cfg0;
1803
1804   from = vlib_frame_vector_args (frame);
1805   n_left_from = frame->n_vectors;
1806   next_index = node->cached_next_index;
1807
1808   while (n_left_from > 0)
1809     {
1810       u32 n_left_to_next;
1811
1812       vlib_get_next_frame (vm, node, next_index,
1813                            to_next, n_left_to_next);
1814
1815       while (n_left_from > 0 && n_left_to_next > 0)
1816         {
1817           vlib_buffer_t * p0;
1818           ethernet_header_t * eth0;
1819           ethernet_arp_header_t * arp0;
1820           u8 * l3h0;
1821           u32 pi0, error0, next0, sw_if_index0;
1822           u16 ethertype0;
1823           u16 bd_index0;
1824           u32 ip0;
1825           u8 * macp0;
1826
1827           pi0 = from[0];
1828           to_next[0] = pi0;
1829           from += 1;
1830           to_next += 1;
1831           n_left_from -= 1;
1832           n_left_to_next -= 1;
1833
1834           p0 = vlib_get_buffer (vm, pi0);
1835           eth0 = vlib_buffer_get_current (p0);
1836           l3h0 = (u8 *)eth0 + vnet_buffer(p0)->l2.l2_len;
1837           ethertype0 = clib_net_to_host_u16(*(u16 *)(l3h0 - 2));
1838           arp0 = (ethernet_arp_header_t *) l3h0;
1839
1840           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) &&
1841                              (p0->flags & VLIB_BUFFER_IS_TRACED)))
1842             {
1843               u8 *t0 = vlib_add_trace (
1844                   vm, node, p0, sizeof(ethernet_arp_input_trace_t));
1845               clib_memcpy (t0, l3h0, sizeof(ethernet_arp_input_trace_t));
1846             }
1847
1848           if (PREDICT_FALSE  (
1849             (ethertype0 != ETHERNET_TYPE_ARP) ||
1850             (arp0->opcode != clib_host_to_net_u16(ETHERNET_ARP_OPCODE_request))))
1851             goto next_l2_feature;
1852
1853           error0 = ETHERNET_ARP_ERROR_replies_sent;
1854           error0 = (arp0->l2_type != clib_net_to_host_u16 (ETHERNET_ARP_HARDWARE_TYPE_ethernet)
1855                     ? ETHERNET_ARP_ERROR_l2_type_not_ethernet
1856                     : error0);
1857           error0 = (arp0->l3_type != clib_net_to_host_u16 (ETHERNET_TYPE_IP4)
1858                     ? ETHERNET_ARP_ERROR_l3_type_not_ip4
1859                     : error0);
1860
1861           sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX];
1862
1863           if (error0)
1864             goto drop;
1865
1866           // Trash ARP packets whose ARP-level source addresses do not
1867           // match their L2-frame-level source addresses */
1868           if (PREDICT_FALSE (
1869             memcmp (eth0->src_address, arp0->ip4_over_ethernet[0].ethernet,
1870                     sizeof (eth0->src_address))))
1871             {
1872               error0 = ETHERNET_ARP_ERROR_l2_address_mismatch;
1873               goto drop;
1874             }
1875
1876           // Check if anyone want ARP request events for L2 BDs
1877           {
1878           pending_resolution_t * mc;
1879           ethernet_arp_main_t * am = &ethernet_arp_main;
1880           uword *p = hash_get (am->mac_changes_by_address, 0);
1881           if (p && (vnet_buffer(p0)->l2.shg == 0))
1882             { // Only SHG 0 interface which is more likely local
1883               u32 next_index = p[0];
1884               while (next_index != (u32)~0)
1885                 {
1886                   int (*fp)(u32, u8 *, u32, u32);
1887                   int rv = 1;
1888                   mc = pool_elt_at_index (am->mac_changes, next_index);
1889                   fp = mc->data_callback;
1890                   // Call the callback, return 1 to suppress dup events */
1891                   if (fp) rv = (*fp)(mc->data,
1892                                      arp0->ip4_over_ethernet[0].ethernet,
1893                                      sw_if_index0,
1894                                      arp0->ip4_over_ethernet[0].ip4.as_u32);
1895                   // Signal the resolver process
1896                   if (rv == 0)
1897                     vlib_process_signal_event (vm, mc->node_index,
1898                                                mc->type_opaque,
1899                                                mc->data);
1900                   next_index = mc->next_index;
1901                 }
1902             }
1903           }
1904
1905           // lookup BD mac_by_ip4 hash table for MAC entry
1906           ip0 = arp0->ip4_over_ethernet[1].ip4.as_u32;
1907           bd_index0 = vnet_buffer(p0)->l2.bd_index;
1908           if (PREDICT_FALSE (
1909             (bd_index0 != last_bd_index) || (last_bd_index == (u16) ~0)))
1910             {
1911               last_bd_index = bd_index0;
1912               last_bd_config = vec_elt_at_index(l2im->bd_configs, bd_index0);
1913             }
1914           macp0 = (u8 *) hash_get (last_bd_config->mac_by_ip4, ip0);
1915
1916           if (PREDICT_FALSE(!macp0))
1917               goto next_l2_feature;     // MAC not found
1918
1919           // MAC found, send ARP reply -
1920           // Convert ARP request packet to ARP reply
1921           arp0->opcode = clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply);
1922           arp0->ip4_over_ethernet[1] = arp0->ip4_over_ethernet[0];
1923           arp0->ip4_over_ethernet[0].ip4.as_u32 = ip0;
1924           clib_memcpy (arp0->ip4_over_ethernet[0].ethernet, macp0, 6);
1925           clib_memcpy (eth0->dst_address, eth0->src_address, 6);
1926           clib_memcpy (eth0->src_address, macp0, 6);
1927           n_replies_sent += 1;
1928
1929           // For BVI, need to use l2-fwd node to send ARP reply as
1930           // l2-output node cannot output packet to BVI properly
1931           cfg0 = vec_elt_at_index(l2im->configs, sw_if_index0);
1932           if (PREDICT_FALSE (cfg0->bvi))
1933             {
1934               vnet_buffer(p0)->l2.feature_bitmap |= L2INPUT_FEAT_FWD;
1935               vnet_buffer (p0)->sw_if_index[VLIB_RX] = 0;
1936               goto next_l2_feature;
1937             }
1938
1939           // Send ARP reply back out input interface through l2-output
1940           vnet_buffer (p0)->sw_if_index[VLIB_TX] = sw_if_index0;
1941           next0 = ARP_TERM_NEXT_L2_OUTPUT;
1942           // Note that output to VXLAN tunnel will fail due to SHG which
1943           // is probably desireable since ARP termination is not intended
1944           // for ARP requests from other hosts. If output to VXLAN tunnel is
1945           // required, however, can just clear the SHG in packet as follows:
1946           //   vnet_buffer(p0)->l2.shg = 0;
1947
1948           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,to_next,
1949                                            n_left_to_next,pi0,next0);
1950           continue;
1951
1952         next_l2_feature:
1953           {
1954             u32 feature_bitmap0 =
1955                 vnet_buffer(p0)->l2.feature_bitmap & ~L2INPUT_FEAT_ARP_TERM;
1956             vnet_buffer(p0)->l2.feature_bitmap = feature_bitmap0;
1957             next0 = feat_bitmap_get_next_node_index(arp_term_next_node_index,
1958                                                     feature_bitmap0);
1959             vlib_validate_buffer_enqueue_x1 (vm, node, next_index,to_next,
1960                                              n_left_to_next,pi0,next0);
1961             continue;
1962           }
1963
1964         drop:
1965           if (0 == arp0->ip4_over_ethernet[0].ip4.as_u32 ||
1966               (arp0->ip4_over_ethernet[0].ip4.as_u32 ==
1967                arp0->ip4_over_ethernet[1].ip4.as_u32))
1968             {
1969               error0 = ETHERNET_ARP_ERROR_gratuitous_arp;
1970             }
1971           next0 = ARP_TERM_NEXT_DROP;
1972           p0->error = node->errors[error0];
1973
1974           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,to_next,
1975                                            n_left_to_next,pi0,next0);
1976         }
1977
1978       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1979     }
1980
1981   vlib_error_count (vm, node->node_index,
1982                     ETHERNET_ARP_ERROR_replies_sent,
1983                     n_replies_sent);
1984   return frame->n_vectors;
1985 }
1986
1987 VLIB_REGISTER_NODE (arp_term_l2bd_node,static) = {
1988   .function = arp_term_l2bd,
1989   .name = "arp-term-l2bd",
1990   .vector_size = sizeof (u32),
1991
1992   .n_errors = ETHERNET_ARP_N_ERROR,
1993   .error_strings = ethernet_arp_error_strings,
1994
1995   .n_next_nodes = ARP_TERM_N_NEXT,
1996   .next_nodes = {
1997     [ARP_TERM_NEXT_L2_OUTPUT] = "l2-output",
1998     [ARP_TERM_NEXT_DROP] = "error-drop",
1999   },
2000
2001   .format_buffer = format_ethernet_arp_header,
2002   .format_trace = format_ethernet_arp_input_trace,
2003 };
2004
2005 clib_error_t *arp_term_init (vlib_main_t *vm)
2006 { // Initialize the feature next-node indexes
2007   feat_bitmap_init_next_nodes(vm,
2008                               arp_term_l2bd_node.index,
2009                               L2INPUT_N_FEAT,
2010                               l2input_get_feat_names(),
2011                               arp_term_next_node_index);
2012   return 0;
2013 }
2014
2015 VLIB_INIT_FUNCTION (arp_term_init);