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 #include <nat/nat44_hairpinning.h>
  26
  27 typedef enum
  28 {
  29   SNAT_HAIRPIN_SRC_NEXT_DROP,
  30   SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT,
  31   SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT_WH,
  32   SNAT_HAIRPIN_SRC_NEXT_INTERFACE_OUTPUT,
  33   SNAT_HAIRPIN_SRC_N_NEXT,
  34 } snat_hairpin_src_next_t;
  35
  36 typedef enum
  37 {
  38   NAT_HAIRPIN_NEXT_LOOKUP,
  39   NAT_HAIRPIN_NEXT_DROP,
  40   NAT_HAIRPIN_NEXT_HANDOFF,
  41   NAT_HAIRPIN_N_NEXT,
  42 } nat_hairpin_next_t;
  43
  44 typedef struct
  45 {
  46   ip4_address_t addr;
  47   u16 port;
  48   u32 fib_index;
  49   u32 session_index;
  50 } nat_hairpin_trace_t;
  51
  52 static u8 *
  53 format_nat_hairpin_trace (u8 * s, va_list * args)
  54 {
  55   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  56   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  57   nat_hairpin_trace_t *t = va_arg (*args, nat_hairpin_trace_t *);
  58
  59   s =
  60     format (s, "new dst addr %U port %u fib-index %u", format_ip4_address,
  61             &t->addr, clib_net_to_host_u16 (t->port), t->fib_index);
  62   if (~0 == t->session_index)
  63     {
  64       s = format (s, " is-static-mapping");
  65     }
  66   else
  67     {
  68       s = format (s, " session-index %u", t->session_index);
  69     }
  70
  71   return s;
  72 }
  73
  74 extern vnet_feature_arc_registration_t vnet_feat_arc_ip4_local;
  75
  76 static_always_inline int
  77 is_hairpinning (snat_main_t * sm, ip4_address_t * dst_addr)
  78 {
  79   snat_address_t *ap;
  80   clib_bihash_kv_8_8_t kv, value;
  81
  82   vec_foreach (ap, sm->addresses)
  83     {
  84       if (ap->addr.as_u32 == dst_addr->as_u32)
  85         return 1;
  86     }
  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, snat_main_t *sm,
  98                   u32 thread_index, vlib_buffer_t *b0, ip4_header_t *ip0,
  99                   udp_header_t *udp0, tcp_header_t *tcp0, u32 proto0,
 100                   int do_trace, u32 *required_thread_index)
 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, 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   u32 old_sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_TX];
 112   /* Check if destination is static mappings */
 113   if (!snat_static_mapping_match
 114       (sm, ip0->dst_address, udp0->dst_port, sm->outside_fib_index, proto0,
 115        &sm0_addr, &sm0_port, &sm0_fib_index, 1, 0, 0, 0, 0, 0, 0))
 116     {
 117       new_dst_addr0 = sm0_addr.as_u32;
 118       new_dst_port0 = sm0_port;
 119       vnet_buffer (b0)->sw_if_index[VLIB_TX] = sm0_fib_index;
 120     }
 121   /* or active session */
 122   else
 123     {
 124       init_nat_k (&kv0, ip0->dst_address, udp0->dst_port,
 125                   sm->outside_fib_index, proto0);
 126       rv = clib_bihash_search_8_8 (&sm->out2in, &kv0, &value0);
 127       if (rv)
 128         {
 129           rv = 0;
 130           goto trace;
 131         }
 132
 133       if (thread_index != nat_value_get_thread_index (&value0))
 134         {
 135           *required_thread_index = nat_value_get_thread_index (&value0);
 136           return 0;
 137         }
 138
 139       si = nat_value_get_session_index (&value0);
 140       s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions, si);
 141       new_dst_addr0 = s0->in2out.addr.as_u32;
 142       new_dst_port0 = s0->in2out.port;
 143       vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
 144     }
 145
 146   /* Check if anything has changed and if not, then return 0. This
 147      helps avoid infinite loop, repeating the three nodes
 148      nat44-hairpinning-->ip4-lookup-->ip4-local, in case nothing has
 149      changed. */
 150   old_dst_addr0 = ip0->dst_address.as_u32;
 151   old_dst_port0 = tcp0->dst;
 152   if (new_dst_addr0 == old_dst_addr0
 153       && new_dst_port0 == old_dst_port0
 154       && vnet_buffer (b0)->sw_if_index[VLIB_TX] == old_sw_if_index)
 155     return 0;
 156
 157   /* Destination is behind the same NAT, use internal address and port */
 158   if (new_dst_addr0)
 159     {
 160       old_dst_addr0 = ip0->dst_address.as_u32;
 161       ip0->dst_address.as_u32 = new_dst_addr0;
 162       sum0 = ip0->checksum;
 163       sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
 164                              ip4_header_t, dst_address);
 165       ip0->checksum = ip_csum_fold (sum0);
 166
 167       old_dst_port0 = tcp0->dst;
 168       if (PREDICT_TRUE (new_dst_port0 != old_dst_port0))
 169         {
 170           if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
 171             {
 172               tcp0->dst = new_dst_port0;
 173               sum0 = tcp0->checksum;
 174               sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
 175                                      ip4_header_t, dst_address);
 176               sum0 = ip_csum_update (sum0, old_dst_port0, new_dst_port0,
 177                                      ip4_header_t /* cheat */ , length);
 178               tcp0->checksum = ip_csum_fold (sum0);
 179             }
 180           else
 181             {
 182               udp0->dst_port = new_dst_port0;
 183               udp0->checksum = 0;
 184             }
 185         }
 186       else
 187         {
 188           if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
 189             {
 190               sum0 = tcp0->checksum;
 191               sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
 192                                      ip4_header_t, dst_address);
 193               tcp0->checksum = ip_csum_fold (sum0);
 194             }
 195         }
 196       rv = 1;
 197       goto trace;
 198     }
 199   rv = 0;
 200 trace:
 201   if (do_trace && PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 202                                  && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 203     {
 204       nat_hairpin_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
 205       t->addr.as_u32 = new_dst_addr0;
 206       t->port = new_dst_port0;
 207       t->fib_index = vnet_buffer (b0)->sw_if_index[VLIB_TX];
 208       if (s0)
 209         {
 210           t->session_index = si;
 211         }
 212       else
 213         {
 214           t->session_index = ~0;
 215         }
 216     }
 217   return rv;
 218 }
 219 #endif
 220
 221 #ifndef CLIB_MARCH_VARIANT
 222 u32
 223 snat_icmp_hairpinning (snat_main_t *sm, vlib_buffer_t *b0, u32 thread_index,
 224                        ip4_header_t *ip0, icmp46_header_t *icmp0,
 225                        u32 *required_thread_index)
 226 {
 227   clib_bihash_kv_8_8_t kv0, value0;
 228   u32 old_dst_addr0, new_dst_addr0;
 229   u32 old_addr0, new_addr0;
 230   u16 old_port0, new_port0;
 231   u16 old_checksum0, new_checksum0;
 232   u32 si, ti = 0;
 233   ip_csum_t sum0;
 234   snat_session_t *s0;
 235   snat_static_mapping_t *m0;
 236
 237   if (icmp_type_is_error_message
 238       (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags))
 239     {
 240       ip4_header_t *inner_ip0 = 0;
 241       tcp_udp_header_t *l4_header = 0;
 242
 243       inner_ip0 = (ip4_header_t *) ((icmp_echo_header_t *) (icmp0 + 1) + 1);
 244       l4_header = ip4_next_header (inner_ip0);
 245       u32 protocol = ip_proto_to_nat_proto (inner_ip0->protocol);
 246
 247       if (protocol != NAT_PROTOCOL_TCP && protocol != NAT_PROTOCOL_UDP)
 248         return 1;
 249
 250       init_nat_k (&kv0, ip0->dst_address, l4_header->src_port,
 251                   sm->outside_fib_index, protocol);
 252       if (clib_bihash_search_8_8 (&sm->out2in, &kv0, &value0))
 253         return 1;
 254       ti = nat_value_get_thread_index (&value0);
 255       if (ti != thread_index)
 256         {
 257           *required_thread_index = ti;
 258           return 1;
 259         }
 260       si = nat_value_get_session_index (&value0);
 261       s0 = pool_elt_at_index (sm->per_thread_data[ti].sessions, si);
 262       new_dst_addr0 = s0->in2out.addr.as_u32;
 263       vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
 264
 265       /* update inner source IP address */
 266       old_addr0 = inner_ip0->src_address.as_u32;
 267       inner_ip0->src_address.as_u32 = new_dst_addr0;
 268       new_addr0 = inner_ip0->src_address.as_u32;
 269       sum0 = icmp0->checksum;
 270       sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 271                              src_address);
 272       icmp0->checksum = ip_csum_fold (sum0);
 273
 274       /* update inner IP header checksum */
 275       old_checksum0 = inner_ip0->checksum;
 276       sum0 = inner_ip0->checksum;
 277       sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 278                              src_address);
 279       inner_ip0->checksum = ip_csum_fold (sum0);
 280       new_checksum0 = inner_ip0->checksum;
 281       sum0 = icmp0->checksum;
 282       sum0 = ip_csum_update (sum0, old_checksum0, new_checksum0, ip4_header_t,
 283                              checksum);
 284       icmp0->checksum = ip_csum_fold (sum0);
 285
 286       /* update inner source port */
 287       old_port0 = l4_header->src_port;
 288       l4_header->src_port = s0->in2out.port;
 289       new_port0 = l4_header->src_port;
 290       sum0 = icmp0->checksum;
 291       sum0 = ip_csum_update (sum0, old_port0, new_port0, tcp_udp_header_t,
 292                              src_port);
 293       icmp0->checksum = ip_csum_fold (sum0);
 294     }
 295   else
 296     {
 297       init_nat_k (&kv0, ip0->dst_address, 0, sm->outside_fib_index, 0);
 298       if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv0,
 299                                   &value0))
 300         {
 301           icmp_echo_header_t *echo0 = (icmp_echo_header_t *) (icmp0 + 1);
 302           u16 icmp_id0 = echo0->identifier;
 303           init_nat_k (&kv0, ip0->dst_address, icmp_id0, sm->outside_fib_index,
 304                       NAT_PROTOCOL_ICMP);
 305           int rv = clib_bihash_search_8_8 (&sm->out2in, &kv0, &value0);
 306           if (!rv)
 307             {
 308               ti = nat_value_get_thread_index (&value0);
 309               if (ti != thread_index)
 310                 {
 311                   *required_thread_index = ti;
 312                   return 1;
 313                 }
 314               si = nat_value_get_session_index (&value0);
 315               s0 = pool_elt_at_index (sm->per_thread_data[ti].sessions, si);
 316               new_dst_addr0 = s0->in2out.addr.as_u32;
 317               vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
 318               echo0->identifier = s0->in2out.port;
 319               sum0 = icmp0->checksum;
 320               sum0 = ip_csum_update (sum0, icmp_id0, s0->in2out.port,
 321                                      icmp_echo_header_t, identifier);
 322               icmp0->checksum = ip_csum_fold (sum0);
 323               goto change_addr;
 324             }
 325
 326           return 1;
 327         }
 328
 329       m0 = pool_elt_at_index (sm->static_mappings, value0.value);
 330
 331       new_dst_addr0 = m0->local_addr.as_u32;
 332       if (vnet_buffer (b0)->sw_if_index[VLIB_TX] == ~0)
 333         vnet_buffer (b0)->sw_if_index[VLIB_TX] = m0->fib_index;
 334     }
 335 change_addr:
 336   /* Destination is behind the same NAT, use internal address and port */
 337   if (new_dst_addr0)
 338     {
 339       old_dst_addr0 = ip0->dst_address.as_u32;
 340       ip0->dst_address.as_u32 = new_dst_addr0;
 341       sum0 = ip0->checksum;
 342       sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
 343                              ip4_header_t, dst_address);
 344       ip0->checksum = ip_csum_fold (sum0);
 345     }
 346   return 0;
 347 }
 348 #endif
 349
 350 #ifndef CLIB_MARCH_VARIANT
 351 void
 352 nat_hairpinning_sm_unknown_proto (snat_main_t * sm,
 353                                   vlib_buffer_t * b, ip4_header_t * ip)
 354 {
 355   clib_bihash_kv_8_8_t kv, value;
 356   snat_static_mapping_t *m;
 357   u32 old_addr, new_addr;
 358   ip_csum_t sum;
 359
 360   init_nat_k (&kv, ip->dst_address, 0, 0, 0);
 361   if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
 362     return;
 363
 364   m = pool_elt_at_index (sm->static_mappings, value.value);
 365
 366   old_addr = ip->dst_address.as_u32;
 367   new_addr = ip->dst_address.as_u32 = m->local_addr.as_u32;
 368   sum = ip->checksum;
 369   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
 370   ip->checksum = ip_csum_fold (sum);
 371
 372   if (vnet_buffer (b)->sw_if_index[VLIB_TX] == ~0)
 373     vnet_buffer (b)->sw_if_index[VLIB_TX] = m->fib_index;
 374 }
 375 #endif
 376
 377 static inline uword
 378 nat44_hairpinning_fn_inline (vlib_main_t *vm, vlib_node_runtime_t *node,
 379                              vlib_frame_t *frame)
 380 {
 381   u32 n_left_from, *from, *to_next;
 382   u32 thread_index = vm->thread_index;
 383   nat_hairpin_next_t next_index;
 384   snat_main_t *sm = &snat_main;
 385   vnet_feature_main_t *fm = &feature_main;
 386   u8 arc_index = vnet_feat_arc_ip4_local.feature_arc_index;
 387   vnet_feature_config_main_t *cm = &fm->feature_config_mains[arc_index];
 388
 389   from = vlib_frame_vector_args (frame);
 390   n_left_from = frame->n_vectors;
 391   next_index = node->cached_next_index;
 392
 393   while (n_left_from > 0)
 394     {
 395       u32 n_left_to_next;
 396
 397       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 398
 399       while (n_left_from > 0 && n_left_to_next > 0)
 400         {
 401           u32 bi0;
 402           vlib_buffer_t *b0;
 403           u32 next0;
 404           ip4_header_t *ip0;
 405           u32 proto0;
 406           udp_header_t *udp0;
 407           tcp_header_t *tcp0;
 408           u32 sw_if_index0;
 409           u32 required_thread_index = thread_index;
 410
 411           /* speculatively enqueue b0 to the current next frame */
 412           bi0 = from[0];
 413           to_next[0] = bi0;
 414           from += 1;
 415           to_next += 1;
 416           n_left_from -= 1;
 417           n_left_to_next -= 1;
 418
 419           b0 = vlib_get_buffer (vm, bi0);
 420           ip0 = vlib_buffer_get_current (b0);
 421           udp0 = ip4_next_header (ip0);
 422           tcp0 = (tcp_header_t *) udp0;
 423           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 424
 425           proto0 = ip_proto_to_nat_proto (ip0->protocol);
 426           int next0_resolved = 0;
 427
 428           if (snat_hairpinning (vm, node, sm, thread_index, b0, ip0, udp0,
 429                                 tcp0, proto0, 1 /* do_trace */,
 430                                 &required_thread_index))
 431             {
 432               next0 = NAT_HAIRPIN_NEXT_LOOKUP;
 433               next0_resolved = 1;
 434             }
 435
 436           if (thread_index != required_thread_index)
 437             {
 438               vnet_buffer (b0)->snat.required_thread_index =
 439                 required_thread_index;
 440               next0 = NAT_HAIRPIN_NEXT_HANDOFF;
 441               next0_resolved = 1;
 442             }
 443
 444           if (!next0_resolved)
 445             vnet_get_config_data (&cm->config_main, &b0->current_config_index,
 446                                   &next0, 0);
 447
 448           if (next0 != NAT_HAIRPIN_NEXT_DROP)
 449             {
 450               vlib_increment_simple_counter (&sm->counters.hairpinning,
 451                                              vm->thread_index, sw_if_index0,
 452                                              1);
 453             }
 454
 455           /* verify speculative enqueue, maybe switch current next frame */
 456           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 457                                            to_next, n_left_to_next,
 458                                            bi0, next0);
 459         }
 460
 461       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 462     }
 463
 464   return frame->n_vectors;
 465 }
 466
 467 VLIB_NODE_FN (nat44_hairpinning_node) (vlib_main_t * vm,
 468                                        vlib_node_runtime_t * node,
 469                                        vlib_frame_t * frame)
 470 {
 471   return nat44_hairpinning_fn_inline (vm, node, frame);
 472 }
 473
 474 VLIB_REGISTER_NODE (nat44_hairpinning_node) = {
 475   .name = "nat44-hairpinning",
 476   .vector_size = sizeof (u32),
 477   .type = VLIB_NODE_TYPE_INTERNAL,
 478   .format_trace = format_nat_hairpin_trace,
 479   .n_next_nodes = NAT_HAIRPIN_N_NEXT,
 480   .next_nodes = {
 481     [NAT_HAIRPIN_NEXT_DROP] = "error-drop",
 482     [NAT_HAIRPIN_NEXT_LOOKUP] = "ip4-lookup",
 483     [NAT_HAIRPIN_NEXT_HANDOFF] = "nat44-hairpinning-handoff",
 484   },
 485 };
 486
 487 VLIB_NODE_FN (nat44_hairpinning_handoff_node)
 488 (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame)
 489 {
 490   return nat44_hairpinning_handoff_fn_inline (
 491     vm, node, frame, snat_main.nat44_hairpinning_fq_index);
 492 }
 493
 494 VLIB_REGISTER_NODE (nat44_hairpinning_handoff_node) = {
 495   .name = "nat44-hairpinning-handoff",
 496   .vector_size = sizeof (u32),
 497   .n_errors = ARRAY_LEN(nat44_hairpinning_handoff_error_strings),
 498   .error_strings = nat44_hairpinning_handoff_error_strings,
 499   .format_trace = format_nat44_hairpinning_handoff_trace,
 500
 501   .n_next_nodes = 1,
 502
 503   .next_nodes = {
 504     [0] = "error-drop",
 505   },
 506 };
 507
 508 static inline uword
 509 snat_hairpin_dst_fn_inline (vlib_main_t *vm, vlib_node_runtime_t *node,
 510                             vlib_frame_t *frame)
 511 {
 512   u32 n_left_from, *from, *to_next;
 513   u32 thread_index = vm->thread_index;
 514   nat_hairpin_next_t next_index;
 515   snat_main_t *sm = &snat_main;
 516
 517   from = vlib_frame_vector_args (frame);
 518   n_left_from = frame->n_vectors;
 519   next_index = node->cached_next_index;
 520
 521   while (n_left_from > 0)
 522     {
 523       u32 n_left_to_next;
 524
 525       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 526
 527       while (n_left_from > 0 && n_left_to_next > 0)
 528         {
 529           u32 bi0;
 530           vlib_buffer_t *b0;
 531           u32 next0;
 532           ip4_header_t *ip0;
 533           u32 proto0;
 534           u32 sw_if_index0;
 535           u32 required_thread_index = thread_index;
 536
 537           /* speculatively enqueue b0 to the current next frame */
 538           bi0 = from[0];
 539           to_next[0] = bi0;
 540           from += 1;
 541           to_next += 1;
 542           n_left_from -= 1;
 543           n_left_to_next -= 1;
 544
 545           b0 = vlib_get_buffer (vm, bi0);
 546           next0 = NAT_HAIRPIN_NEXT_LOOKUP;
 547           ip0 = vlib_buffer_get_current (b0);
 548           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 549
 550           proto0 = ip_proto_to_nat_proto (ip0->protocol);
 551
 552           vnet_buffer (b0)->snat.flags = 0;
 553           if (PREDICT_FALSE (is_hairpinning (sm, &ip0->dst_address)))
 554             {
 555               if (proto0 == NAT_PROTOCOL_TCP || proto0 == NAT_PROTOCOL_UDP)
 556                 {
 557                   udp_header_t *udp0 = ip4_next_header (ip0);
 558                   tcp_header_t *tcp0 = (tcp_header_t *) udp0;
 559
 560                   snat_hairpinning (vm, node, sm, thread_index, b0, ip0, udp0,
 561                                     tcp0, proto0, 1 /* do_trace */,
 562                                     &required_thread_index);
 563                 }
 564               else if (proto0 == NAT_PROTOCOL_ICMP)
 565                 {
 566                   icmp46_header_t *icmp0 = ip4_next_header (ip0);
 567
 568                   snat_icmp_hairpinning (sm, b0, thread_index, ip0, icmp0,
 569                                          &required_thread_index);
 570                 }
 571               else
 572                 {
 573                   nat_hairpinning_sm_unknown_proto (sm, b0, ip0);
 574                 }
 575
 576               vnet_buffer (b0)->snat.flags = SNAT_FLAG_HAIRPINNING;
 577             }
 578
 579           if (thread_index != required_thread_index)
 580             {
 581               vnet_buffer (b0)->snat.required_thread_index =
 582                 required_thread_index;
 583               next0 = NAT_HAIRPIN_NEXT_HANDOFF;
 584             }
 585
 586           if (next0 != NAT_HAIRPIN_NEXT_DROP)
 587             {
 588               vlib_increment_simple_counter (&sm->counters.hairpinning,
 589                                              vm->thread_index, sw_if_index0,
 590                                              1);
 591             }
 592
 593           /* verify speculative enqueue, maybe switch current next frame */
 594           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 595                                            to_next, n_left_to_next,
 596                                            bi0, next0);
 597         }
 598
 599       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 600     }
 601
 602   return frame->n_vectors;
 603 }
 604
 605 VLIB_NODE_FN (snat_hairpin_dst_node) (vlib_main_t * vm,
 606                                       vlib_node_runtime_t * node,
 607                                       vlib_frame_t * frame)
 608 {
 609   return snat_hairpin_dst_fn_inline (vm, node, frame);
 610 }
 611
 612 VLIB_REGISTER_NODE (snat_hairpin_dst_node) = {
 613   .name = "nat44-hairpin-dst",
 614   .vector_size = sizeof (u32),
 615   .type = VLIB_NODE_TYPE_INTERNAL,
 616   .format_trace = format_nat_hairpin_trace,
 617   .n_next_nodes = NAT_HAIRPIN_N_NEXT,
 618   .next_nodes = {
 619     [NAT_HAIRPIN_NEXT_DROP] = "error-drop",
 620     [NAT_HAIRPIN_NEXT_LOOKUP] = "ip4-lookup",
 621     [NAT_HAIRPIN_NEXT_HANDOFF] = "nat44-hairpin-dst-handoff",
 622   },
 623 };
 624
 625 VLIB_NODE_FN (nat44_hairpinning_dst_handoff_node)
 626 (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame)
 627 {
 628   return nat44_hairpinning_handoff_fn_inline (
 629     vm, node, frame, snat_main.snat_hairpin_dst_fq_index);
 630 }
 631
 632 VLIB_REGISTER_NODE (nat44_hairpinning_dst_handoff_node) = {
 633   .name = "nat44-hairpin-dst-handoff",
 634   .vector_size = sizeof (u32),
 635   .n_errors = ARRAY_LEN(nat44_hairpinning_handoff_error_strings),
 636   .error_strings = nat44_hairpinning_handoff_error_strings,
 637   .format_trace = format_nat44_hairpinning_handoff_trace,
 638
 639   .n_next_nodes = 1,
 640
 641   .next_nodes = {
 642     [0] = "error-drop",
 643   },
 644 };
 645
 646 static inline uword
 647 snat_hairpin_src_fn_inline (vlib_main_t *vm, vlib_node_runtime_t *node,
 648                             vlib_frame_t *frame)
 649 {
 650   u32 n_left_from, *from, *to_next;
 651   snat_hairpin_src_next_t next_index;
 652   snat_main_t *sm = &snat_main;
 653
 654   from = vlib_frame_vector_args (frame);
 655   n_left_from = frame->n_vectors;
 656   next_index = node->cached_next_index;
 657
 658   while (n_left_from > 0)
 659     {
 660       u32 n_left_to_next;
 661
 662       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 663
 664       while (n_left_from > 0 && n_left_to_next > 0)
 665         {
 666           u32 bi0;
 667           vlib_buffer_t *b0;
 668           u32 next0;
 669           snat_interface_t *i;
 670           u32 sw_if_index0;
 671
 672           /* speculatively enqueue b0 to the current next frame */
 673           bi0 = from[0];
 674           to_next[0] = bi0;
 675           from += 1;
 676           to_next += 1;
 677           n_left_from -= 1;
 678           n_left_to_next -= 1;
 679
 680           b0 = vlib_get_buffer (vm, bi0);
 681           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 682           vnet_feature_next (&next0, b0);
 683
 684           pool_foreach (i, sm->output_feature_interfaces)
 685            {
 686             /* Only packets from NAT inside interface */
 687             if ((nat_interface_is_inside(i)) && (sw_if_index0 == i->sw_if_index))
 688               {
 689                 if (PREDICT_FALSE ((vnet_buffer (b0)->snat.flags) &
 690                                     SNAT_FLAG_HAIRPINNING))
 691                   {
 692                     if (PREDICT_TRUE (sm->num_workers > 1))
 693                       next0 = SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT_WH;
 694                     else
 695                       next0 = SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT;
 696                   }
 697                 break;
 698               }
 699           }
 700
 701           if (next0 != SNAT_HAIRPIN_SRC_NEXT_DROP)
 702             {
 703               vlib_increment_simple_counter (&sm->counters.hairpinning,
 704                                              vm->thread_index, sw_if_index0,
 705                                              1);
 706             }
 707
 708           /* verify speculative enqueue, maybe switch current next frame */
 709           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 710                                            to_next, n_left_to_next,
 711                                            bi0, next0);
 712         }
 713
 714       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 715     }
 716
 717   return frame->n_vectors;
 718 }
 719
 720 VLIB_NODE_FN (snat_hairpin_src_node) (vlib_main_t * vm,
 721                                       vlib_node_runtime_t * node,
 722                                       vlib_frame_t * frame)
 723 {
 724   return snat_hairpin_src_fn_inline (vm, node, frame);
 725 }
 726
 727 VLIB_REGISTER_NODE (snat_hairpin_src_node) = {
 728   .name = "nat44-hairpin-src",
 729   .vector_size = sizeof (u32),
 730   .type = VLIB_NODE_TYPE_INTERNAL,
 731   .n_next_nodes = SNAT_HAIRPIN_SRC_N_NEXT,
 732   .next_nodes = {
 733      [SNAT_HAIRPIN_SRC_NEXT_DROP] = "error-drop",
 734      [SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT] = "nat44-in2out-output",
 735      [SNAT_HAIRPIN_SRC_NEXT_INTERFACE_OUTPUT] = "interface-output",
 736      [SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT_WH] = "nat44-in2out-output-worker-handoff",
 737   },
 738 };
 739
 740 /*
 741  * fd.io coding-style-patch-verification: ON
 742  *
 743  * Local Variables:
 744  * eval: (c-set-style "gnu")
 745  * End:
 746  */