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   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       if (sm->num_workers > 1)
 125         ti =
 126           (clib_net_to_host_u16 (udp0->dst_port) -
 127            1024) / sm->port_per_thread;
 128       else
 129         ti = sm->num_workers;
 130
 131       if (is_ed)
 132         {
 133           clib_bihash_kv_16_8_t ed_kv, ed_value;
 134           init_ed_k (&ed_kv, ip0->dst_address, udp0->dst_port,
 135                      ip0->src_address, udp0->src_port, sm->outside_fib_index,
 136                      ip0->protocol);
 137           rv = clib_bihash_search_16_8 (&sm->out2in_ed, &ed_kv, &ed_value);
 138           ASSERT (ti == ed_value_get_thread_index (&ed_value));
 139           si = ed_value_get_session_index (&ed_value);
 140         }
 141       else
 142         {
 143
 144           init_nat_k (&kv0, ip0->dst_address, udp0->dst_port,
 145                       sm->outside_fib_index, proto0);
 146           rv =
 147             clib_bihash_search_8_8 (&sm->per_thread_data[ti].out2in, &kv0,
 148                                     &value0);
 149           si = value0.value;
 150         }
 151       if (rv)
 152         {
 153           rv = 0;
 154           goto trace;
 155         }
 156
 157       s0 = pool_elt_at_index (sm->per_thread_data[ti].sessions, si);
 158       new_dst_addr0 = s0->in2out.addr.as_u32;
 159       new_dst_port0 = s0->in2out.port;
 160       vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
 161     }
 162
 163   /* Check if anything has changed and if not, then return 0. This
 164      helps avoid infinite loop, repeating the three nodes
 165      nat44-hairpinning-->ip4-lookup-->ip4-local, in case nothing has
 166      changed. */
 167   old_dst_addr0 = ip0->dst_address.as_u32;
 168   old_dst_port0 = tcp0->dst;
 169   if (new_dst_addr0 == old_dst_addr0
 170       && new_dst_port0 == old_dst_port0
 171       && vnet_buffer (b0)->sw_if_index[VLIB_TX] == old_sw_if_index)
 172     return 0;
 173
 174   /* Destination is behind the same NAT, use internal address and port */
 175   if (new_dst_addr0)
 176     {
 177       old_dst_addr0 = ip0->dst_address.as_u32;
 178       ip0->dst_address.as_u32 = new_dst_addr0;
 179       sum0 = ip0->checksum;
 180       sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
 181                              ip4_header_t, dst_address);
 182       ip0->checksum = ip_csum_fold (sum0);
 183
 184       old_dst_port0 = tcp0->dst;
 185       if (PREDICT_TRUE (new_dst_port0 != old_dst_port0))
 186         {
 187           if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
 188             {
 189               tcp0->dst = new_dst_port0;
 190               sum0 = tcp0->checksum;
 191               sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
 192                                      ip4_header_t, dst_address);
 193               sum0 = ip_csum_update (sum0, old_dst_port0, new_dst_port0,
 194                                      ip4_header_t /* cheat */ , length);
 195               tcp0->checksum = ip_csum_fold (sum0);
 196             }
 197           else
 198             {
 199               udp0->dst_port = new_dst_port0;
 200               udp0->checksum = 0;
 201             }
 202         }
 203       else
 204         {
 205           if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
 206             {
 207               sum0 = tcp0->checksum;
 208               sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
 209                                      ip4_header_t, dst_address);
 210               tcp0->checksum = ip_csum_fold (sum0);
 211             }
 212         }
 213       rv = 1;
 214       goto trace;
 215     }
 216   rv = 0;
 217 trace:
 218   if (do_trace && PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 219                                  && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 220     {
 221       nat_hairpin_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
 222       t->addr.as_u32 = new_dst_addr0;
 223       t->port = new_dst_port0;
 224       t->fib_index = vnet_buffer (b0)->sw_if_index[VLIB_TX];
 225       if (s0)
 226         {
 227           t->session_index = si;
 228         }
 229       else
 230         {
 231           t->session_index = ~0;
 232         }
 233     }
 234   return rv;
 235 }
 236 #endif
 237
 238 #ifndef CLIB_MARCH_VARIANT
 239 u32
 240 snat_icmp_hairpinning (snat_main_t * sm,
 241                        vlib_buffer_t * b0,
 242                        ip4_header_t * ip0, icmp46_header_t * icmp0, int is_ed)
 243 {
 244   clib_bihash_kv_8_8_t kv0, value0;
 245   u32 old_dst_addr0, new_dst_addr0;
 246   u32 old_addr0, new_addr0;
 247   u16 old_port0, new_port0;
 248   u16 old_checksum0, new_checksum0;
 249   u32 si, ti = 0;
 250   ip_csum_t sum0;
 251   snat_session_t *s0;
 252   snat_static_mapping_t *m0;
 253
 254   if (icmp_type_is_error_message
 255       (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags))
 256     {
 257       ip4_header_t *inner_ip0 = 0;
 258       tcp_udp_header_t *l4_header = 0;
 259
 260       inner_ip0 = (ip4_header_t *) ((icmp_echo_header_t *) (icmp0 + 1) + 1);
 261       l4_header = ip4_next_header (inner_ip0);
 262       u32 protocol = ip_proto_to_nat_proto (inner_ip0->protocol);
 263
 264       if (protocol != NAT_PROTOCOL_TCP && protocol != NAT_PROTOCOL_UDP)
 265         return 1;
 266
 267       if (is_ed)
 268         {
 269           clib_bihash_kv_16_8_t ed_kv, ed_value;
 270           init_ed_k (&ed_kv, ip0->dst_address, l4_header->src_port,
 271                      ip0->src_address, l4_header->dst_port,
 272                      sm->outside_fib_index, inner_ip0->protocol);
 273           if (clib_bihash_search_16_8 (&sm->out2in_ed, &ed_kv, &ed_value))
 274             return 1;
 275           ASSERT (ti == ed_value_get_thread_index (&ed_value));
 276           si = ed_value_get_session_index (&ed_value);
 277         }
 278       else
 279         {
 280           init_nat_k (&kv0, ip0->dst_address, l4_header->src_port,
 281                       sm->outside_fib_index, protocol);
 282           if (clib_bihash_search_8_8
 283               (&sm->per_thread_data[ti].out2in, &kv0, &value0))
 284             return 1;
 285           si = value0.value;
 286         }
 287       s0 = pool_elt_at_index (sm->per_thread_data[ti].sessions, si);
 288       new_dst_addr0 = s0->in2out.addr.as_u32;
 289       vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
 290
 291       /* update inner source IP address */
 292       old_addr0 = inner_ip0->src_address.as_u32;
 293       inner_ip0->src_address.as_u32 = new_dst_addr0;
 294       new_addr0 = inner_ip0->src_address.as_u32;
 295       sum0 = icmp0->checksum;
 296       sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 297                              src_address);
 298       icmp0->checksum = ip_csum_fold (sum0);
 299
 300       /* update inner IP header checksum */
 301       old_checksum0 = inner_ip0->checksum;
 302       sum0 = inner_ip0->checksum;
 303       sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 304                              src_address);
 305       inner_ip0->checksum = ip_csum_fold (sum0);
 306       new_checksum0 = inner_ip0->checksum;
 307       sum0 = icmp0->checksum;
 308       sum0 = ip_csum_update (sum0, old_checksum0, new_checksum0, ip4_header_t,
 309                              checksum);
 310       icmp0->checksum = ip_csum_fold (sum0);
 311
 312       /* update inner source port */
 313       old_port0 = l4_header->src_port;
 314       l4_header->src_port = s0->in2out.port;
 315       new_port0 = l4_header->src_port;
 316       sum0 = icmp0->checksum;
 317       sum0 = ip_csum_update (sum0, old_port0, new_port0, tcp_udp_header_t,
 318                              src_port);
 319       icmp0->checksum = ip_csum_fold (sum0);
 320     }
 321   else
 322     {
 323       init_nat_k (&kv0, ip0->dst_address, 0, sm->outside_fib_index, 0);
 324       if (clib_bihash_search_8_8
 325           (&sm->static_mapping_by_external, &kv0, &value0))
 326         {
 327           if (!is_ed)
 328             {
 329               icmp_echo_header_t *echo0 = (icmp_echo_header_t *) (icmp0 + 1);
 330               u16 icmp_id0 = echo0->identifier;
 331               init_nat_k (&kv0, ip0->dst_address, icmp_id0,
 332                           sm->outside_fib_index, NAT_PROTOCOL_ICMP);
 333               if (sm->num_workers > 1)
 334                 ti =
 335                   (clib_net_to_host_u16 (icmp_id0) -
 336                    1024) / sm->port_per_thread;
 337               else
 338                 ti = sm->num_workers;
 339               int rv =
 340                 clib_bihash_search_8_8 (&sm->per_thread_data[ti].out2in, &kv0,
 341                                         &value0);
 342               if (!rv)
 343                 {
 344                   si = value0.value;
 345                   s0 =
 346                     pool_elt_at_index (sm->per_thread_data[ti].sessions, si);
 347                   new_dst_addr0 = s0->in2out.addr.as_u32;
 348                   vnet_buffer (b0)->sw_if_index[VLIB_TX] =
 349                     s0->in2out.fib_index;
 350                   echo0->identifier = s0->in2out.port;
 351                   sum0 = icmp0->checksum;
 352                   sum0 = ip_csum_update (sum0, icmp_id0, s0->in2out.port,
 353                                          icmp_echo_header_t, identifier);
 354                   icmp0->checksum = ip_csum_fold (sum0);
 355                   goto change_addr;
 356                 }
 357             }
 358
 359           return 1;
 360         }
 361
 362       m0 = pool_elt_at_index (sm->static_mappings, value0.value);
 363
 364       new_dst_addr0 = m0->local_addr.as_u32;
 365       if (vnet_buffer (b0)->sw_if_index[VLIB_TX] == ~0)
 366         vnet_buffer (b0)->sw_if_index[VLIB_TX] = m0->fib_index;
 367     }
 368 change_addr:
 369   /* Destination is behind the same NAT, use internal address and port */
 370   if (new_dst_addr0)
 371     {
 372       old_dst_addr0 = ip0->dst_address.as_u32;
 373       ip0->dst_address.as_u32 = new_dst_addr0;
 374       sum0 = ip0->checksum;
 375       sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
 376                              ip4_header_t, dst_address);
 377       ip0->checksum = ip_csum_fold (sum0);
 378     }
 379   return 0;
 380 }
 381 #endif
 382
 383 #ifndef CLIB_MARCH_VARIANT
 384 void
 385 nat_hairpinning_sm_unknown_proto (snat_main_t * sm,
 386                                   vlib_buffer_t * b, ip4_header_t * ip)
 387 {
 388   clib_bihash_kv_8_8_t kv, value;
 389   snat_static_mapping_t *m;
 390   u32 old_addr, new_addr;
 391   ip_csum_t sum;
 392
 393   init_nat_k (&kv, ip->dst_address, 0, 0, 0);
 394   if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
 395     return;
 396
 397   m = pool_elt_at_index (sm->static_mappings, value.value);
 398
 399   old_addr = ip->dst_address.as_u32;
 400   new_addr = ip->dst_address.as_u32 = m->local_addr.as_u32;
 401   sum = ip->checksum;
 402   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
 403   ip->checksum = ip_csum_fold (sum);
 404
 405   if (vnet_buffer (b)->sw_if_index[VLIB_TX] == ~0)
 406     vnet_buffer (b)->sw_if_index[VLIB_TX] = m->fib_index;
 407 }
 408 #endif
 409
 410 #ifndef CLIB_MARCH_VARIANT
 411 void
 412 nat44_ed_hairpinning_unknown_proto (snat_main_t * sm,
 413                                     vlib_buffer_t * b, ip4_header_t * ip)
 414 {
 415   u32 old_addr, new_addr = 0, ti = 0;
 416   clib_bihash_kv_8_8_t kv, value;
 417   clib_bihash_kv_16_8_t s_kv, s_value;
 418   snat_static_mapping_t *m;
 419   ip_csum_t sum;
 420   snat_session_t *s;
 421
 422   if (sm->num_workers > 1)
 423     ti = sm->worker_out2in_cb (b, ip, sm->outside_fib_index, 0);
 424   else
 425     ti = sm->num_workers;
 426
 427   old_addr = ip->dst_address.as_u32;
 428   init_ed_k (&s_kv, ip->dst_address, 0, ip->src_address, 0,
 429              sm->outside_fib_index, ip->protocol);
 430   if (clib_bihash_search_16_8 (&sm->out2in_ed, &s_kv, &s_value))
 431     {
 432       init_nat_k (&kv, ip->dst_address, 0, 0, 0);
 433       if (clib_bihash_search_8_8
 434           (&sm->static_mapping_by_external, &kv, &value))
 435         return;
 436
 437       m = pool_elt_at_index (sm->static_mappings, value.value);
 438       if (vnet_buffer (b)->sw_if_index[VLIB_TX] == ~0)
 439         vnet_buffer (b)->sw_if_index[VLIB_TX] = m->fib_index;
 440       new_addr = ip->dst_address.as_u32 = m->local_addr.as_u32;
 441     }
 442   else
 443     {
 444       ASSERT (ti == ed_value_get_thread_index (&s_value));
 445       s =
 446         pool_elt_at_index (sm->per_thread_data[ti].sessions,
 447                            ed_value_get_session_index (&s_value));
 448       if (vnet_buffer (b)->sw_if_index[VLIB_TX] == ~0)
 449         vnet_buffer (b)->sw_if_index[VLIB_TX] = s->in2out.fib_index;
 450       new_addr = ip->dst_address.as_u32 = s->in2out.addr.as_u32;
 451     }
 452   sum = ip->checksum;
 453   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
 454   ip->checksum = ip_csum_fold (sum);
 455 }
 456 #endif
 457
 458 static inline uword
 459 nat44_hairpinning_fn_inline (vlib_main_t * vm,
 460                              vlib_node_runtime_t * node,
 461                              vlib_frame_t * frame, int is_ed)
 462 {
 463   u32 n_left_from, *from, *to_next;
 464   nat_hairpin_next_t next_index;
 465   snat_main_t *sm = &snat_main;
 466   vnet_feature_main_t *fm = &feature_main;
 467   u8 arc_index = vnet_feat_arc_ip4_local.feature_arc_index;
 468   vnet_feature_config_main_t *cm = &fm->feature_config_mains[arc_index];
 469
 470   from = vlib_frame_vector_args (frame);
 471   n_left_from = frame->n_vectors;
 472   next_index = node->cached_next_index;
 473
 474   while (n_left_from > 0)
 475     {
 476       u32 n_left_to_next;
 477
 478       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 479
 480       while (n_left_from > 0 && n_left_to_next > 0)
 481         {
 482           u32 bi0;
 483           vlib_buffer_t *b0;
 484           u32 next0;
 485           ip4_header_t *ip0;
 486           u32 proto0;
 487           udp_header_t *udp0;
 488           tcp_header_t *tcp0;
 489           u32 sw_if_index0;
 490
 491           /* speculatively enqueue b0 to the current next frame */
 492           bi0 = from[0];
 493           to_next[0] = bi0;
 494           from += 1;
 495           to_next += 1;
 496           n_left_from -= 1;
 497           n_left_to_next -= 1;
 498
 499           b0 = vlib_get_buffer (vm, bi0);
 500           ip0 = vlib_buffer_get_current (b0);
 501           udp0 = ip4_next_header (ip0);
 502           tcp0 = (tcp_header_t *) udp0;
 503           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 504
 505           proto0 = ip_proto_to_nat_proto (ip0->protocol);
 506
 507           vnet_get_config_data (&cm->config_main, &b0->current_config_index,
 508                                 &next0, 0);
 509
 510           if (snat_hairpinning
 511               (vm, node, sm, b0, ip0, udp0, tcp0, proto0, is_ed,
 512                1 /* do_trace */ ))
 513             next0 = NAT_HAIRPIN_NEXT_LOOKUP;
 514
 515           if (next0 != NAT_HAIRPIN_NEXT_DROP)
 516             {
 517               vlib_increment_simple_counter (&sm->counters.hairpinning,
 518                                              vm->thread_index, sw_if_index0,
 519                                              1);
 520             }
 521
 522           /* verify speculative enqueue, maybe switch current next frame */
 523           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 524                                            to_next, n_left_to_next,
 525                                            bi0, next0);
 526         }
 527
 528       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 529     }
 530
 531   return frame->n_vectors;
 532 }
 533
 534 VLIB_NODE_FN (nat44_hairpinning_node) (vlib_main_t * vm,
 535                                        vlib_node_runtime_t * node,
 536                                        vlib_frame_t * frame)
 537 {
 538   return nat44_hairpinning_fn_inline (vm, node, frame, 0);
 539 }
 540
 541 /* *INDENT-OFF* */
 542 VLIB_REGISTER_NODE (nat44_hairpinning_node) = {
 543   .name = "nat44-hairpinning",
 544   .vector_size = sizeof (u32),
 545   .type = VLIB_NODE_TYPE_INTERNAL,
 546   .format_trace = format_nat_hairpin_trace,
 547   .n_next_nodes = NAT_HAIRPIN_N_NEXT,
 548   .next_nodes = {
 549     [NAT_HAIRPIN_NEXT_DROP] = "error-drop",
 550     [NAT_HAIRPIN_NEXT_LOOKUP] = "ip4-lookup",
 551   },
 552 };
 553 /* *INDENT-ON* */
 554
 555 VLIB_NODE_FN (nat44_ed_hairpinning_node) (vlib_main_t * vm,
 556                                           vlib_node_runtime_t * node,
 557                                           vlib_frame_t * frame)
 558 {
 559   return nat44_hairpinning_fn_inline (vm, node, frame, 1);
 560 }
 561
 562 /* *INDENT-OFF* */
 563 VLIB_REGISTER_NODE (nat44_ed_hairpinning_node) = {
 564   .name = "nat44-ed-hairpinning",
 565   .vector_size = sizeof (u32),
 566   .type = VLIB_NODE_TYPE_INTERNAL,
 567   .format_trace = format_nat_hairpin_trace,
 568   .n_next_nodes = NAT_HAIRPIN_N_NEXT,
 569   .next_nodes = {
 570     [NAT_HAIRPIN_NEXT_DROP] = "error-drop",
 571     [NAT_HAIRPIN_NEXT_LOOKUP] = "ip4-lookup",
 572   },
 573 };
 574 /* *INDENT-ON* */
 575
 576 static inline uword
 577 snat_hairpin_dst_fn_inline (vlib_main_t * vm,
 578                             vlib_node_runtime_t * node,
 579                             vlib_frame_t * frame, int is_ed)
 580 {
 581   u32 n_left_from, *from, *to_next;
 582   nat_hairpin_next_t next_index;
 583   snat_main_t *sm = &snat_main;
 584
 585   from = vlib_frame_vector_args (frame);
 586   n_left_from = frame->n_vectors;
 587   next_index = node->cached_next_index;
 588
 589   while (n_left_from > 0)
 590     {
 591       u32 n_left_to_next;
 592
 593       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 594
 595       while (n_left_from > 0 && n_left_to_next > 0)
 596         {
 597           u32 bi0;
 598           vlib_buffer_t *b0;
 599           u32 next0;
 600           ip4_header_t *ip0;
 601           u32 proto0;
 602           u32 sw_if_index0;
 603
 604           /* speculatively enqueue b0 to the current next frame */
 605           bi0 = from[0];
 606           to_next[0] = bi0;
 607           from += 1;
 608           to_next += 1;
 609           n_left_from -= 1;
 610           n_left_to_next -= 1;
 611
 612           b0 = vlib_get_buffer (vm, bi0);
 613           next0 = NAT_HAIRPIN_NEXT_LOOKUP;
 614           ip0 = vlib_buffer_get_current (b0);
 615           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 616
 617           proto0 = ip_proto_to_nat_proto (ip0->protocol);
 618
 619           vnet_buffer (b0)->snat.flags = 0;
 620           if (PREDICT_FALSE (is_hairpinning (sm, &ip0->dst_address)))
 621             {
 622               if (proto0 == NAT_PROTOCOL_TCP || proto0 == NAT_PROTOCOL_UDP)
 623                 {
 624                   udp_header_t *udp0 = ip4_next_header (ip0);
 625                   tcp_header_t *tcp0 = (tcp_header_t *) udp0;
 626
 627                   snat_hairpinning (vm, node, sm, b0, ip0, udp0, tcp0, proto0,
 628                                     is_ed, 1 /* do_trace */ );
 629                 }
 630               else if (proto0 == NAT_PROTOCOL_ICMP)
 631                 {
 632                   icmp46_header_t *icmp0 = ip4_next_header (ip0);
 633
 634                   snat_icmp_hairpinning (sm, b0, ip0, icmp0, is_ed);
 635                 }
 636               else
 637                 {
 638                   if (is_ed)
 639                     nat44_ed_hairpinning_unknown_proto (sm, b0, ip0);
 640                   else
 641                     nat_hairpinning_sm_unknown_proto (sm, b0, ip0);
 642                 }
 643
 644               vnet_buffer (b0)->snat.flags = SNAT_FLAG_HAIRPINNING;
 645             }
 646
 647
 648           if (next0 != NAT_HAIRPIN_NEXT_DROP)
 649             {
 650               vlib_increment_simple_counter (&sm->counters.hairpinning,
 651                                              vm->thread_index, sw_if_index0,
 652                                              1);
 653             }
 654
 655           /* verify speculative enqueue, maybe switch current next frame */
 656           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 657                                            to_next, n_left_to_next,
 658                                            bi0, next0);
 659         }
 660
 661       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 662     }
 663
 664   return frame->n_vectors;
 665 }
 666
 667 VLIB_NODE_FN (snat_hairpin_dst_node) (vlib_main_t * vm,
 668                                       vlib_node_runtime_t * node,
 669                                       vlib_frame_t * frame)
 670 {
 671   return snat_hairpin_dst_fn_inline (vm, node, frame, 0);
 672 }
 673
 674 /* *INDENT-OFF* */
 675 VLIB_REGISTER_NODE (snat_hairpin_dst_node) = {
 676   .name = "nat44-hairpin-dst",
 677   .vector_size = sizeof (u32),
 678   .type = VLIB_NODE_TYPE_INTERNAL,
 679   .format_trace = format_nat_hairpin_trace,
 680   .n_next_nodes = NAT_HAIRPIN_N_NEXT,
 681   .next_nodes = {
 682     [NAT_HAIRPIN_NEXT_DROP] = "error-drop",
 683     [NAT_HAIRPIN_NEXT_LOOKUP] = "ip4-lookup",
 684   },
 685 };
 686 /* *INDENT-ON* */
 687
 688 VLIB_NODE_FN (nat44_ed_hairpin_dst_node) (vlib_main_t * vm,
 689                                           vlib_node_runtime_t * node,
 690                                           vlib_frame_t * frame)
 691 {
 692   return snat_hairpin_dst_fn_inline (vm, node, frame, 1);
 693 }
 694
 695 /* *INDENT-OFF* */
 696 VLIB_REGISTER_NODE (nat44_ed_hairpin_dst_node) = {
 697   .name = "nat44-ed-hairpin-dst",
 698   .vector_size = sizeof (u32),
 699   .type = VLIB_NODE_TYPE_INTERNAL,
 700   .format_trace = format_nat_hairpin_trace,
 701   .n_next_nodes = NAT_HAIRPIN_N_NEXT,
 702   .next_nodes = {
 703     [NAT_HAIRPIN_NEXT_DROP] = "error-drop",
 704     [NAT_HAIRPIN_NEXT_LOOKUP] = "ip4-lookup",
 705   },
 706 };
 707 /* *INDENT-ON* */
 708
 709 static inline uword
 710 snat_hairpin_src_fn_inline (vlib_main_t * vm,
 711                             vlib_node_runtime_t * node,
 712                             vlib_frame_t * frame, int is_ed)
 713 {
 714   u32 n_left_from, *from, *to_next;
 715   snat_hairpin_src_next_t next_index;
 716   snat_main_t *sm = &snat_main;
 717
 718   from = vlib_frame_vector_args (frame);
 719   n_left_from = frame->n_vectors;
 720   next_index = node->cached_next_index;
 721
 722   while (n_left_from > 0)
 723     {
 724       u32 n_left_to_next;
 725
 726       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 727
 728       while (n_left_from > 0 && n_left_to_next > 0)
 729         {
 730           u32 bi0;
 731           vlib_buffer_t *b0;
 732           u32 next0;
 733           snat_interface_t *i;
 734           u32 sw_if_index0;
 735
 736           /* speculatively enqueue b0 to the current next frame */
 737           bi0 = from[0];
 738           to_next[0] = bi0;
 739           from += 1;
 740           to_next += 1;
 741           n_left_from -= 1;
 742           n_left_to_next -= 1;
 743
 744           b0 = vlib_get_buffer (vm, bi0);
 745           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 746           vnet_feature_next (&next0, b0);
 747
 748           /* *INDENT-OFF* */
 749           pool_foreach (i, sm->output_feature_interfaces,
 750           ({
 751             /* Only packets from NAT inside interface */
 752             if ((nat_interface_is_inside(i)) && (sw_if_index0 == i->sw_if_index))
 753               {
 754                 if (PREDICT_FALSE ((vnet_buffer (b0)->snat.flags) &
 755                                     SNAT_FLAG_HAIRPINNING))
 756                   {
 757                     if (PREDICT_TRUE (sm->num_workers > 1))
 758                       next0 = SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT_WH;
 759                     else
 760                       next0 = SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT;
 761                   }
 762                 break;
 763               }
 764           }));
 765           /* *INDENT-ON* */
 766
 767           if (next0 != SNAT_HAIRPIN_SRC_NEXT_DROP)
 768             {
 769               vlib_increment_simple_counter (&sm->counters.hairpinning,
 770                                              vm->thread_index, sw_if_index0,
 771                                              1);
 772             }
 773
 774           /* verify speculative enqueue, maybe switch current next frame */
 775           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 776                                            to_next, n_left_to_next,
 777                                            bi0, next0);
 778         }
 779
 780       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 781     }
 782
 783   return frame->n_vectors;
 784 }
 785
 786 VLIB_NODE_FN (snat_hairpin_src_node) (vlib_main_t * vm,
 787                                       vlib_node_runtime_t * node,
 788                                       vlib_frame_t * frame)
 789 {
 790   return snat_hairpin_src_fn_inline (vm, node, frame, 0);
 791 }
 792
 793 /* *INDENT-OFF* */
 794 VLIB_REGISTER_NODE (snat_hairpin_src_node) = {
 795   .name = "nat44-hairpin-src",
 796   .vector_size = sizeof (u32),
 797   .type = VLIB_NODE_TYPE_INTERNAL,
 798   .n_next_nodes = SNAT_HAIRPIN_SRC_N_NEXT,
 799   .next_nodes = {
 800      [SNAT_HAIRPIN_SRC_NEXT_DROP] = "error-drop",
 801      [SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT] = "nat44-in2out-output",
 802      [SNAT_HAIRPIN_SRC_NEXT_INTERFACE_OUTPUT] = "interface-output",
 803      [SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT_WH] = "nat44-in2out-output-worker-handoff",
 804   },
 805 };
 806 /* *INDENT-ON* */
 807
 808 VLIB_NODE_FN (nat44_ed_hairpin_src_node) (vlib_main_t * vm,
 809                                           vlib_node_runtime_t * node,
 810                                           vlib_frame_t * frame)
 811 {
 812   return snat_hairpin_src_fn_inline (vm, node, frame, 1);
 813 }
 814
 815 /* *INDENT-OFF* */
 816 VLIB_REGISTER_NODE (nat44_ed_hairpin_src_node) = {
 817   .name = "nat44-ed-hairpin-src",
 818   .vector_size = sizeof (u32),
 819   .type = VLIB_NODE_TYPE_INTERNAL,
 820   .n_next_nodes = SNAT_HAIRPIN_SRC_N_NEXT,
 821   .next_nodes = {
 822      [SNAT_HAIRPIN_SRC_NEXT_DROP] = "error-drop",
 823      [SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT] = "nat44-ed-in2out-output",
 824      [SNAT_HAIRPIN_SRC_NEXT_INTERFACE_OUTPUT] = "interface-output",
 825      [SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT_WH] = "nat44-in2out-output-worker-handoff",
 826   },
 827 };
 828 /* *INDENT-ON* */
 829
 830 /*
 831  * fd.io coding-style-patch-verification: ON
 832  *
 833  * Local Variables:
 834  * eval: (c-set-style "gnu")
 835  * End:
 836  */