src/plugins/nat/nat44_hairpinning.c

   1 /*
   2  * Copyright (c) 2018 Cisco and/or its affiliates.
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15 /**
  16  * @file
  17  * @brief NAT44 hairpinning
  18  */
  19
  20 #include <vlib/vlib.h>
  21 #include <vnet/vnet.h>
  22 #include <vnet/fib/ip4_fib.h>
  23 #include <nat/nat.h>
  24 #include <nat/nat_inlines.h>
  25
  26 typedef enum
  27 {
  28   SNAT_HAIRPIN_SRC_NEXT_DROP,
  29   SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT,
  30   SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT_WH,
  31   SNAT_HAIRPIN_SRC_NEXT_INTERFACE_OUTPUT,
  32   SNAT_HAIRPIN_SRC_N_NEXT,
  33 } snat_hairpin_src_next_t;
  34
  35 typedef enum
  36 {
  37   NAT_HAIRPIN_NEXT_LOOKUP,
  38   NAT_HAIRPIN_NEXT_DROP,
  39   NAT_HAIRPIN_N_NEXT,
  40 } nat_hairpin_next_t;
  41
  42 typedef struct
  43 {
  44   ip4_address_t addr;
  45   u16 port;
  46   u32 fib_index;
  47   u32 session_index;
  48 } nat_hairpin_trace_t;
  49
  50 static u8 *
  51 format_nat_hairpin_trace (u8 * s, va_list * args)
  52 {
  53   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  54   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  55   nat_hairpin_trace_t *t = va_arg (*args, nat_hairpin_trace_t *);
  56
  57   s =
  58     format (s, "new dst addr %U port %u fib-index %u", format_ip4_address,
  59             &t->addr, clib_net_to_host_u16 (t->port), t->fib_index);
  60   if (~0 == t->session_index)
  61     {
  62       s = format (s, " is-static-mapping");
  63     }
  64   else
  65     {
  66       s = format (s, " session-index %u", t->session_index);
  67     }
  68
  69   return s;
  70 }
  71
  72 extern vnet_feature_arc_registration_t vnet_feat_arc_ip4_local;
  73
  74 static_always_inline int
  75 is_hairpinning (snat_main_t * sm, ip4_address_t * dst_addr)
  76 {
  77   snat_address_t *ap;
  78   clib_bihash_kv_8_8_t kv, value;
  79
  80   /* *INDENT-OFF* */
  81   vec_foreach (ap, sm->addresses)
  82     {
  83       if (ap->addr.as_u32 == dst_addr->as_u32)
  84         return 1;
  85     }
  86   /* *INDENT-ON* */
  87
  88   init_nat_k (&kv, *dst_addr, 0, 0, 0);
  89   if (!clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
  90     return 1;
  91
  92   return 0;
  93 }
  94
  95 #ifndef CLIB_MARCH_VARIANT
  96 int
  97 snat_hairpinning (vlib_main_t * vm, vlib_node_runtime_t * node,
  98                   snat_main_t * sm, vlib_buffer_t * b0, ip4_header_t * ip0,
  99                   udp_header_t * udp0, tcp_header_t * tcp0, u32 proto0,
 100                   int is_ed, int do_trace)
 101 {
 102   snat_session_t *s0 = NULL;
 103   clib_bihash_kv_8_8_t kv0, value0;
 104   ip_csum_t sum0;
 105   u32 new_dst_addr0 = 0, old_dst_addr0, ti = 0, si = ~0;
 106   u16 new_dst_port0 = ~0, old_dst_port0;
 107   int rv;
 108   ip4_address_t sm0_addr;
 109   u16 sm0_port;
 110   u32 sm0_fib_index;
 111   /* Check if destination is static mappings */
 112   if (!snat_static_mapping_match
 113       (sm, ip0->dst_address, udp0->dst_port, sm->outside_fib_index, proto0,
 114        &sm0_addr, &sm0_port, &sm0_fib_index, 1, 0, 0, 0, 0, 0, 0))
 115     {
 116       new_dst_addr0 = sm0_addr.as_u32;
 117       new_dst_port0 = sm0_port;
 118       vnet_buffer (b0)->sw_if_index[VLIB_TX] = sm0_fib_index;
 119     }
 120   /* or active session */
 121   else
 122     {
 123       if (sm->num_workers > 1)
 124         ti =
 125           (clib_net_to_host_u16 (udp0->dst_port) -
 126            1024) / sm->port_per_thread;
 127       else
 128         ti = sm->num_workers;
 129
 130       if (is_ed)
 131         {
 132           clib_bihash_kv_16_8_t ed_kv, ed_value;
 133           init_ed_k (&ed_kv, ip0->dst_address, udp0->dst_port,
 134                      ip0->src_address, udp0->src_port, sm->outside_fib_index,
 135                      ip0->protocol);
 136           rv = clib_bihash_search_16_8 (&sm->out2in_ed, &ed_kv, &ed_value);
 137           ASSERT (ti == ed_value_get_thread_index (&ed_value));
 138           si = ed_value_get_session_index (&ed_value);
 139         }
 140       else
 141         {
 142
 143           init_nat_k (&kv0, ip0->dst_address, udp0->dst_port,
 144                       sm->outside_fib_index, proto0);
 145           rv =
 146             clib_bihash_search_8_8 (&sm->per_thread_data[ti].out2in, &kv0,
 147                                     &value0);
 148           si = value0.value;
 149         }
 150       if (rv)
 151         {
 152           rv = 0;
 153           goto trace;
 154         }
 155
 156       s0 = pool_elt_at_index (sm->per_thread_data[ti].sessions, si);
 157       new_dst_addr0 = s0->in2out.addr.as_u32;
 158       new_dst_port0 = s0->in2out.port;
 159       vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
 160     }
 161
 162   /* Destination is behind the same NAT, use internal address and port */
 163   if (new_dst_addr0)
 164     {
 165       old_dst_addr0 = ip0->dst_address.as_u32;
 166       ip0->dst_address.as_u32 = new_dst_addr0;
 167       sum0 = ip0->checksum;
 168       sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
 169                              ip4_header_t, dst_address);
 170       ip0->checksum = ip_csum_fold (sum0);
 171
 172       old_dst_port0 = tcp0->dst;
 173       if (PREDICT_TRUE (new_dst_port0 != old_dst_port0))
 174         {
 175           if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
 176             {
 177               tcp0->dst = new_dst_port0;
 178               sum0 = tcp0->checksum;
 179               sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
 180                                      ip4_header_t, dst_address);
 181               sum0 = ip_csum_update (sum0, old_dst_port0, new_dst_port0,
 182                                      ip4_header_t /* cheat */ , length);
 183               tcp0->checksum = ip_csum_fold (sum0);
 184             }
 185           else
 186             {
 187               udp0->dst_port = new_dst_port0;
 188               udp0->checksum = 0;
 189             }
 190         }
 191       else
 192         {
 193           if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
 194             {
 195               sum0 = tcp0->checksum;
 196               sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
 197                                      ip4_header_t, dst_address);
 198               tcp0->checksum = ip_csum_fold (sum0);
 199             }
 200         }
 201       rv = 1;
 202       goto trace;
 203     }
 204   rv = 0;
 205 trace:
 206   if (do_trace && PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 207                                  && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 208     {
 209       nat_hairpin_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
 210       t->addr.as_u32 = new_dst_addr0;
 211       t->port = new_dst_port0;
 212       t->fib_index = vnet_buffer (b0)->sw_if_index[VLIB_TX];
 213       if (s0)
 214         {
 215           t->session_index = si;
 216         }
 217       else
 218         {
 219           t->session_index = ~0;
 220         }
 221     }
 222   return rv;
 223 }
 224 #endif
 225
 226 #ifndef CLIB_MARCH_VARIANT
 227 u32
 228 snat_icmp_hairpinning (snat_main_t * sm,
 229                        vlib_buffer_t * b0,
 230                        ip4_header_t * ip0, icmp46_header_t * icmp0, int is_ed)
 231 {
 232   clib_bihash_kv_8_8_t kv0, value0;
 233   u32 old_dst_addr0, new_dst_addr0;
 234   u32 old_addr0, new_addr0;
 235   u16 old_port0, new_port0;
 236   u16 old_checksum0, new_checksum0;
 237   u32 si, ti = 0;
 238   ip_csum_t sum0;
 239   snat_session_t *s0;
 240   snat_static_mapping_t *m0;
 241
 242   if (icmp_type_is_error_message
 243       (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags))
 244     {
 245       ip4_header_t *inner_ip0 = 0;
 246       tcp_udp_header_t *l4_header = 0;
 247
 248       inner_ip0 = (ip4_header_t *) ((icmp_echo_header_t *) (icmp0 + 1) + 1);
 249       l4_header = ip4_next_header (inner_ip0);
 250       u32 protocol = ip_proto_to_nat_proto (inner_ip0->protocol);
 251
 252       if (protocol != NAT_PROTOCOL_TCP && protocol != NAT_PROTOCOL_UDP)
 253         return 1;
 254
 255       if (is_ed)
 256         {
 257           clib_bihash_kv_16_8_t ed_kv, ed_value;
 258           init_ed_k (&ed_kv, ip0->dst_address, l4_header->src_port,
 259                      ip0->src_address, l4_header->dst_port,
 260                      sm->outside_fib_index, inner_ip0->protocol);
 261           if (clib_bihash_search_16_8 (&sm->out2in_ed, &ed_kv, &ed_value))
 262             return 1;
 263           ASSERT (ti == ed_value_get_thread_index (&ed_value));
 264           si = ed_value_get_session_index (&ed_value);
 265         }
 266       else
 267         {
 268           init_nat_k (&kv0, ip0->dst_address, l4_header->src_port,
 269                       sm->outside_fib_index, protocol);
 270           if (clib_bihash_search_8_8
 271               (&sm->per_thread_data[ti].out2in, &kv0, &value0))
 272             return 1;
 273           si = value0.value;
 274         }
 275       s0 = pool_elt_at_index (sm->per_thread_data[ti].sessions, si);
 276       new_dst_addr0 = s0->in2out.addr.as_u32;
 277       vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
 278
 279       /* update inner source IP address */
 280       old_addr0 = inner_ip0->src_address.as_u32;
 281       inner_ip0->src_address.as_u32 = new_dst_addr0;
 282       new_addr0 = inner_ip0->src_address.as_u32;
 283       sum0 = icmp0->checksum;
 284       sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 285                              src_address);
 286       icmp0->checksum = ip_csum_fold (sum0);
 287
 288       /* update inner IP header checksum */
 289       old_checksum0 = inner_ip0->checksum;
 290       sum0 = inner_ip0->checksum;
 291       sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 292                              src_address);
 293       inner_ip0->checksum = ip_csum_fold (sum0);
 294       new_checksum0 = inner_ip0->checksum;
 295       sum0 = icmp0->checksum;
 296       sum0 = ip_csum_update (sum0, old_checksum0, new_checksum0, ip4_header_t,
 297                              checksum);
 298       icmp0->checksum = ip_csum_fold (sum0);
 299
 300       /* update inner source port */
 301       old_port0 = l4_header->src_port;
 302       l4_header->src_port = s0->in2out.port;
 303       new_port0 = l4_header->src_port;
 304       sum0 = icmp0->checksum;
 305       sum0 = ip_csum_update (sum0, old_port0, new_port0, tcp_udp_header_t,
 306                              src_port);
 307       icmp0->checksum = ip_csum_fold (sum0);
 308     }
 309   else
 310     {
 311       init_nat_k (&kv0, ip0->dst_address, 0, sm->outside_fib_index, 0);
 312       if (clib_bihash_search_8_8
 313           (&sm->static_mapping_by_external, &kv0, &value0))
 314         {
 315           if (!is_ed)
 316             {
 317               icmp_echo_header_t *echo0 = (icmp_echo_header_t *) (icmp0 + 1);
 318               u16 icmp_id0 = echo0->identifier;
 319               init_nat_k (&kv0, ip0->dst_address, icmp_id0,
 320                           sm->outside_fib_index, NAT_PROTOCOL_ICMP);
 321               if (sm->num_workers > 1)
 322                 ti =
 323                   (clib_net_to_host_u16 (icmp_id0) -
 324                    1024) / sm->port_per_thread;
 325               else
 326                 ti = sm->num_workers;
 327               int rv =
 328                 clib_bihash_search_8_8 (&sm->per_thread_data[ti].out2in, &kv0,
 329                                         &value0);
 330               if (!rv)
 331                 {
 332                   si = value0.value;
 333                   s0 =
 334                     pool_elt_at_index (sm->per_thread_data[ti].sessions, si);
 335                   new_dst_addr0 = s0->in2out.addr.as_u32;
 336                   vnet_buffer (b0)->sw_if_index[VLIB_TX] =
 337                     s0->in2out.fib_index;
 338                   echo0->identifier = s0->in2out.port;
 339                   sum0 = icmp0->checksum;
 340                   sum0 = ip_csum_update (sum0, icmp_id0, s0->in2out.port,
 341                                          icmp_echo_header_t, identifier);
 342                   icmp0->checksum = ip_csum_fold (sum0);
 343                   goto change_addr;
 344                 }
 345             }
 346
 347           return 1;
 348         }
 349
 350       m0 = pool_elt_at_index (sm->static_mappings, value0.value);
 351
 352       new_dst_addr0 = m0->local_addr.as_u32;
 353       if (vnet_buffer (b0)->sw_if_index[VLIB_TX] == ~0)
 354         vnet_buffer (b0)->sw_if_index[VLIB_TX] = m0->fib_index;
 355     }
 356 change_addr:
 357   /* Destination is behind the same NAT, use internal address and port */
 358   if (new_dst_addr0)
 359     {
 360       old_dst_addr0 = ip0->dst_address.as_u32;
 361       ip0->dst_address.as_u32 = new_dst_addr0;
 362       sum0 = ip0->checksum;
 363       sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
 364                              ip4_header_t, dst_address);
 365       ip0->checksum = ip_csum_fold (sum0);
 366     }
 367   return 0;
 368 }
 369 #endif
 370
 371 #ifndef CLIB_MARCH_VARIANT
 372 void
 373 nat_hairpinning_sm_unknown_proto (snat_main_t * sm,
 374                                   vlib_buffer_t * b, ip4_header_t * ip)
 375 {
 376   clib_bihash_kv_8_8_t kv, value;
 377   snat_static_mapping_t *m;
 378   u32 old_addr, new_addr;
 379   ip_csum_t sum;
 380
 381   init_nat_k (&kv, ip->dst_address, 0, 0, 0);
 382   if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
 383     return;
 384
 385   m = pool_elt_at_index (sm->static_mappings, value.value);
 386
 387   old_addr = ip->dst_address.as_u32;
 388   new_addr = ip->dst_address.as_u32 = m->local_addr.as_u32;
 389   sum = ip->checksum;
 390   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
 391   ip->checksum = ip_csum_fold (sum);
 392
 393   if (vnet_buffer (b)->sw_if_index[VLIB_TX] == ~0)
 394     vnet_buffer (b)->sw_if_index[VLIB_TX] = m->fib_index;
 395 }
 396 #endif
 397
 398 #ifndef CLIB_MARCH_VARIANT
 399 void
 400 nat44_ed_hairpinning_unknown_proto (snat_main_t * sm,
 401                                     vlib_buffer_t * b, ip4_header_t * ip)
 402 {
 403   u32 old_addr, new_addr = 0, ti = 0;
 404   clib_bihash_kv_8_8_t kv, value;
 405   clib_bihash_kv_16_8_t s_kv, s_value;
 406   snat_static_mapping_t *m;
 407   ip_csum_t sum;
 408   snat_session_t *s;
 409
 410   if (sm->num_workers > 1)
 411     ti = sm->worker_out2in_cb (b, ip, sm->outside_fib_index, 0);
 412   else
 413     ti = sm->num_workers;
 414
 415   old_addr = ip->dst_address.as_u32;
 416   init_ed_k (&s_kv, ip->dst_address, 0, ip->src_address, 0,
 417              sm->outside_fib_index, ip->protocol);
 418   if (clib_bihash_search_16_8 (&sm->out2in_ed, &s_kv, &s_value))
 419     {
 420       init_nat_k (&kv, ip->dst_address, 0, 0, 0);
 421       if (clib_bihash_search_8_8
 422           (&sm->static_mapping_by_external, &kv, &value))
 423         return;
 424
 425       m = pool_elt_at_index (sm->static_mappings, value.value);
 426       if (vnet_buffer (b)->sw_if_index[VLIB_TX] == ~0)
 427         vnet_buffer (b)->sw_if_index[VLIB_TX] = m->fib_index;
 428       new_addr = ip->dst_address.as_u32 = m->local_addr.as_u32;
 429     }
 430   else
 431     {
 432       ASSERT (ti == ed_value_get_thread_index (&s_value));
 433       s =
 434         pool_elt_at_index (sm->per_thread_data[ti].sessions,
 435                            ed_value_get_session_index (&s_value));
 436       if (vnet_buffer (b)->sw_if_index[VLIB_TX] == ~0)
 437         vnet_buffer (b)->sw_if_index[VLIB_TX] = s->in2out.fib_index;
 438       new_addr = ip->dst_address.as_u32 = s->in2out.addr.as_u32;
 439     }
 440   sum = ip->checksum;
 441   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
 442   ip->checksum = ip_csum_fold (sum);
 443 }
 444 #endif
 445
 446 static inline uword
 447 nat44_hairpinning_fn_inline (vlib_main_t * vm,
 448                              vlib_node_runtime_t * node,
 449                              vlib_frame_t * frame, int is_ed)
 450 {
 451   u32 n_left_from, *from, *to_next;
 452   nat_hairpin_next_t next_index;
 453   snat_main_t *sm = &snat_main;
 454   vnet_feature_main_t *fm = &feature_main;
 455   u8 arc_index = vnet_feat_arc_ip4_local.feature_arc_index;
 456   vnet_feature_config_main_t *cm = &fm->feature_config_mains[arc_index];
 457
 458   from = vlib_frame_vector_args (frame);
 459   n_left_from = frame->n_vectors;
 460   next_index = node->cached_next_index;
 461
 462   while (n_left_from > 0)
 463     {
 464       u32 n_left_to_next;
 465
 466       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 467
 468       while (n_left_from > 0 && n_left_to_next > 0)
 469         {
 470           u32 bi0;
 471           vlib_buffer_t *b0;
 472           u32 next0;
 473           ip4_header_t *ip0;
 474           u32 proto0;
 475           udp_header_t *udp0;
 476           tcp_header_t *tcp0;
 477           u32 sw_if_index0;
 478
 479           /* speculatively enqueue b0 to the current next frame */
 480           bi0 = from[0];
 481           to_next[0] = bi0;
 482           from += 1;
 483           to_next += 1;
 484           n_left_from -= 1;
 485           n_left_to_next -= 1;
 486
 487           b0 = vlib_get_buffer (vm, bi0);
 488           ip0 = vlib_buffer_get_current (b0);
 489           udp0 = ip4_next_header (ip0);
 490           tcp0 = (tcp_header_t *) udp0;
 491           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 492
 493           proto0 = ip_proto_to_nat_proto (ip0->protocol);
 494
 495           vnet_get_config_data (&cm->config_main, &b0->current_config_index,
 496                                 &next0, 0);
 497
 498           if (snat_hairpinning
 499               (vm, node, sm, b0, ip0, udp0, tcp0, proto0, is_ed,
 500                1 /* do_trace */ ))
 501             next0 = NAT_HAIRPIN_NEXT_LOOKUP;
 502
 503           if (next0 != NAT_HAIRPIN_NEXT_DROP)
 504             {
 505               vlib_increment_simple_counter (&sm->counters.hairpinning,
 506                                              vm->thread_index, sw_if_index0,
 507                                              1);
 508             }
 509
 510           /* verify speculative enqueue, maybe switch current next frame */
 511           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 512                                            to_next, n_left_to_next,
 513                                            bi0, next0);
 514         }
 515
 516       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 517     }
 518
 519   return frame->n_vectors;
 520 }
 521
 522 VLIB_NODE_FN (nat44_hairpinning_node) (vlib_main_t * vm,
 523                                        vlib_node_runtime_t * node,
 524                                        vlib_frame_t * frame)
 525 {
 526   return nat44_hairpinning_fn_inline (vm, node, frame, 0);
 527 }
 528
 529 /* *INDENT-OFF* */
 530 VLIB_REGISTER_NODE (nat44_hairpinning_node) = {
 531   .name = "nat44-hairpinning",
 532   .vector_size = sizeof (u32),
 533   .type = VLIB_NODE_TYPE_INTERNAL,
 534   .format_trace = format_nat_hairpin_trace,
 535   .n_next_nodes = NAT_HAIRPIN_N_NEXT,
 536   .next_nodes = {
 537     [NAT_HAIRPIN_NEXT_DROP] = "error-drop",
 538     [NAT_HAIRPIN_NEXT_LOOKUP] = "ip4-lookup",
 539   },
 540 };
 541 /* *INDENT-ON* */
 542
 543 VLIB_NODE_FN (nat44_ed_hairpinning_node) (vlib_main_t * vm,
 544                                           vlib_node_runtime_t * node,
 545                                           vlib_frame_t * frame)
 546 {
 547   return nat44_hairpinning_fn_inline (vm, node, frame, 1);
 548 }
 549
 550 /* *INDENT-OFF* */
 551 VLIB_REGISTER_NODE (nat44_ed_hairpinning_node) = {
 552   .name = "nat44-ed-hairpinning",
 553   .vector_size = sizeof (u32),
 554   .type = VLIB_NODE_TYPE_INTERNAL,
 555   .format_trace = format_nat_hairpin_trace,
 556   .n_next_nodes = NAT_HAIRPIN_N_NEXT,
 557   .next_nodes = {
 558     [NAT_HAIRPIN_NEXT_DROP] = "error-drop",
 559     [NAT_HAIRPIN_NEXT_LOOKUP] = "ip4-lookup",
 560   },
 561 };
 562 /* *INDENT-ON* */
 563
 564 static inline uword
 565 snat_hairpin_dst_fn_inline (vlib_main_t * vm,
 566                             vlib_node_runtime_t * node,
 567                             vlib_frame_t * frame, int is_ed)
 568 {
 569   u32 n_left_from, *from, *to_next;
 570   nat_hairpin_next_t next_index;
 571   snat_main_t *sm = &snat_main;
 572
 573   from = vlib_frame_vector_args (frame);
 574   n_left_from = frame->n_vectors;
 575   next_index = node->cached_next_index;
 576
 577   while (n_left_from > 0)
 578     {
 579       u32 n_left_to_next;
 580
 581       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 582
 583       while (n_left_from > 0 && n_left_to_next > 0)
 584         {
 585           u32 bi0;
 586           vlib_buffer_t *b0;
 587           u32 next0;
 588           ip4_header_t *ip0;
 589           u32 proto0;
 590           u32 sw_if_index0;
 591
 592           /* speculatively enqueue b0 to the current next frame */
 593           bi0 = from[0];
 594           to_next[0] = bi0;
 595           from += 1;
 596           to_next += 1;
 597           n_left_from -= 1;
 598           n_left_to_next -= 1;
 599
 600           b0 = vlib_get_buffer (vm, bi0);
 601           next0 = NAT_HAIRPIN_NEXT_LOOKUP;
 602           ip0 = vlib_buffer_get_current (b0);
 603           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 604
 605           proto0 = ip_proto_to_nat_proto (ip0->protocol);
 606
 607           vnet_buffer (b0)->snat.flags = 0;
 608           if (PREDICT_FALSE (is_hairpinning (sm, &ip0->dst_address)))
 609             {
 610               if (proto0 == NAT_PROTOCOL_TCP || proto0 == NAT_PROTOCOL_UDP)
 611                 {
 612                   udp_header_t *udp0 = ip4_next_header (ip0);
 613                   tcp_header_t *tcp0 = (tcp_header_t *) udp0;
 614
 615                   snat_hairpinning (vm, node, sm, b0, ip0, udp0, tcp0, proto0,
 616                                     is_ed, 1 /* do_trace */ );
 617                 }
 618               else if (proto0 == NAT_PROTOCOL_ICMP)
 619                 {
 620                   icmp46_header_t *icmp0 = ip4_next_header (ip0);
 621
 622                   snat_icmp_hairpinning (sm, b0, ip0, icmp0, is_ed);
 623                 }
 624               else
 625                 {
 626                   if (is_ed)
 627                     nat44_ed_hairpinning_unknown_proto (sm, b0, ip0);
 628                   else
 629                     nat_hairpinning_sm_unknown_proto (sm, b0, ip0);
 630                 }
 631
 632               vnet_buffer (b0)->snat.flags = SNAT_FLAG_HAIRPINNING;
 633             }
 634
 635
 636           if (next0 != NAT_HAIRPIN_NEXT_DROP)
 637             {
 638               vlib_increment_simple_counter (&sm->counters.hairpinning,
 639                                              vm->thread_index, sw_if_index0,
 640                                              1);
 641             }
 642
 643           /* verify speculative enqueue, maybe switch current next frame */
 644           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 645                                            to_next, n_left_to_next,
 646                                            bi0, next0);
 647         }
 648
 649       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 650     }
 651
 652   return frame->n_vectors;
 653 }
 654
 655 VLIB_NODE_FN (snat_hairpin_dst_node) (vlib_main_t * vm,
 656                                       vlib_node_runtime_t * node,
 657                                       vlib_frame_t * frame)
 658 {
 659   return snat_hairpin_dst_fn_inline (vm, node, frame, 0);
 660 }
 661
 662 /* *INDENT-OFF* */
 663 VLIB_REGISTER_NODE (snat_hairpin_dst_node) = {
 664   .name = "nat44-hairpin-dst",
 665   .vector_size = sizeof (u32),
 666   .type = VLIB_NODE_TYPE_INTERNAL,
 667   .format_trace = format_nat_hairpin_trace,
 668   .n_next_nodes = NAT_HAIRPIN_N_NEXT,
 669   .next_nodes = {
 670     [NAT_HAIRPIN_NEXT_DROP] = "error-drop",
 671     [NAT_HAIRPIN_NEXT_LOOKUP] = "ip4-lookup",
 672   },
 673 };
 674 /* *INDENT-ON* */
 675
 676 VLIB_NODE_FN (nat44_ed_hairpin_dst_node) (vlib_main_t * vm,
 677                                           vlib_node_runtime_t * node,
 678                                           vlib_frame_t * frame)
 679 {
 680   return snat_hairpin_dst_fn_inline (vm, node, frame, 1);
 681 }
 682
 683 /* *INDENT-OFF* */
 684 VLIB_REGISTER_NODE (nat44_ed_hairpin_dst_node) = {
 685   .name = "nat44-ed-hairpin-dst",
 686   .vector_size = sizeof (u32),
 687   .type = VLIB_NODE_TYPE_INTERNAL,
 688   .format_trace = format_nat_hairpin_trace,
 689   .n_next_nodes = NAT_HAIRPIN_N_NEXT,
 690   .next_nodes = {
 691     [NAT_HAIRPIN_NEXT_DROP] = "error-drop",
 692     [NAT_HAIRPIN_NEXT_LOOKUP] = "ip4-lookup",
 693   },
 694 };
 695 /* *INDENT-ON* */
 696
 697 static inline uword
 698 snat_hairpin_src_fn_inline (vlib_main_t * vm,
 699                             vlib_node_runtime_t * node,
 700                             vlib_frame_t * frame, int is_ed)
 701 {
 702   u32 n_left_from, *from, *to_next;
 703   snat_hairpin_src_next_t next_index;
 704   snat_main_t *sm = &snat_main;
 705
 706   from = vlib_frame_vector_args (frame);
 707   n_left_from = frame->n_vectors;
 708   next_index = node->cached_next_index;
 709
 710   while (n_left_from > 0)
 711     {
 712       u32 n_left_to_next;
 713
 714       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 715
 716       while (n_left_from > 0 && n_left_to_next > 0)
 717         {
 718           u32 bi0;
 719           vlib_buffer_t *b0;
 720           u32 next0;
 721           snat_interface_t *i;
 722           u32 sw_if_index0;
 723
 724           /* speculatively enqueue b0 to the current next frame */
 725           bi0 = from[0];
 726           to_next[0] = bi0;
 727           from += 1;
 728           to_next += 1;
 729           n_left_from -= 1;
 730           n_left_to_next -= 1;
 731
 732           b0 = vlib_get_buffer (vm, bi0);
 733           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 734           vnet_feature_next (&next0, b0);
 735
 736           /* *INDENT-OFF* */
 737           pool_foreach (i, sm->output_feature_interfaces,
 738           ({
 739             /* Only packets from NAT inside interface */
 740             if ((nat_interface_is_inside(i)) && (sw_if_index0 == i->sw_if_index))
 741               {
 742                 if (PREDICT_FALSE ((vnet_buffer (b0)->snat.flags) &
 743                                     SNAT_FLAG_HAIRPINNING))
 744                   {
 745                     if (PREDICT_TRUE (sm->num_workers > 1))
 746                       next0 = SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT_WH;
 747                     else
 748                       next0 = SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT;
 749                   }
 750                 break;
 751               }
 752           }));
 753           /* *INDENT-ON* */
 754
 755           if (next0 != SNAT_HAIRPIN_SRC_NEXT_DROP)
 756             {
 757               vlib_increment_simple_counter (&sm->counters.hairpinning,
 758                                              vm->thread_index, sw_if_index0,
 759                                              1);
 760             }
 761
 762           /* verify speculative enqueue, maybe switch current next frame */
 763           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 764                                            to_next, n_left_to_next,
 765                                            bi0, next0);
 766         }
 767
 768       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 769     }
 770
 771   return frame->n_vectors;
 772 }
 773
 774 VLIB_NODE_FN (snat_hairpin_src_node) (vlib_main_t * vm,
 775                                       vlib_node_runtime_t * node,
 776                                       vlib_frame_t * frame)
 777 {
 778   return snat_hairpin_src_fn_inline (vm, node, frame, 0);
 779 }
 780
 781 /* *INDENT-OFF* */
 782 VLIB_REGISTER_NODE (snat_hairpin_src_node) = {
 783   .name = "nat44-hairpin-src",
 784   .vector_size = sizeof (u32),
 785   .type = VLIB_NODE_TYPE_INTERNAL,
 786   .n_next_nodes = SNAT_HAIRPIN_SRC_N_NEXT,
 787   .next_nodes = {
 788      [SNAT_HAIRPIN_SRC_NEXT_DROP] = "error-drop",
 789      [SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT] = "nat44-in2out-output",
 790      [SNAT_HAIRPIN_SRC_NEXT_INTERFACE_OUTPUT] = "interface-output",
 791      [SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT_WH] = "nat44-in2out-output-worker-handoff",
 792   },
 793 };
 794 /* *INDENT-ON* */
 795
 796 VLIB_NODE_FN (nat44_ed_hairpin_src_node) (vlib_main_t * vm,
 797                                           vlib_node_runtime_t * node,
 798                                           vlib_frame_t * frame)
 799 {
 800   return snat_hairpin_src_fn_inline (vm, node, frame, 1);
 801 }
 802
 803 /* *INDENT-OFF* */
 804 VLIB_REGISTER_NODE (nat44_ed_hairpin_src_node) = {
 805   .name = "nat44-ed-hairpin-src",
 806   .vector_size = sizeof (u32),
 807   .type = VLIB_NODE_TYPE_INTERNAL,
 808   .n_next_nodes = SNAT_HAIRPIN_SRC_N_NEXT,
 809   .next_nodes = {
 810      [SNAT_HAIRPIN_SRC_NEXT_DROP] = "error-drop",
 811      [SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT] = "nat44-ed-in2out-output",
 812      [SNAT_HAIRPIN_SRC_NEXT_INTERFACE_OUTPUT] = "interface-output",
 813      [SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT_WH] = "nat44-in2out-output-worker-handoff",
 814   },
 815 };
 816 /* *INDENT-ON* */
 817
 818 /*
 819  * fd.io coding-style-patch-verification: ON
 820  *
 821  * Local Variables:
 822  * eval: (c-set-style "gnu")
 823  * End:
 824  */