src/plugins/nat/nat44-ed/nat44_ed_out2in.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 endpoint-dependent outside to inside network translation
  18  */
  19
  20 #include <vlib/vlib.h>
  21 #include <vnet/vnet.h>
  22 #include <vnet/ip/ip.h>
  23 #include <vnet/ethernet/ethernet.h>
  24 #include <vnet/fib/ip4_fib.h>
  25 #include <vnet/udp/udp_local.h>
  26 #include <vppinfra/error.h>
  27
  28 #include <nat/lib/nat_syslog.h>
  29 #include <nat/lib/ipfix_logging.h>
  30
  31 #include <nat/nat44-ed/nat44_ed.h>
  32 #include <nat/nat44-ed/nat44_ed_inlines.h>
  33
  34 static char *nat_out2in_ed_error_strings[] = {
  35 #define _(sym,string) string,
  36   foreach_nat_out2in_ed_error
  37 #undef _
  38 };
  39
  40 typedef struct
  41 {
  42   u32 sw_if_index;
  43   u32 next_index;
  44   u32 session_index;
  45   nat_translation_error_e translation_error;
  46   nat_6t_flow_t i2of;
  47   nat_6t_flow_t o2if;
  48   clib_bihash_kv_16_8_t search_key;
  49   u8 is_slow_path;
  50   u8 translation_via_i2of;
  51   u8 lookup_skipped;
  52 } nat44_ed_out2in_trace_t;
  53
  54 static u8 *
  55 format_nat44_ed_out2in_trace (u8 * s, va_list * args)
  56 {
  57   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  58   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  59   nat44_ed_out2in_trace_t *t = va_arg (*args, nat44_ed_out2in_trace_t *);
  60   char *tag;
  61
  62   tag =
  63     t->is_slow_path ? "NAT44_OUT2IN_ED_SLOW_PATH" :
  64     "NAT44_OUT2IN_ED_FAST_PATH";
  65
  66   s = format (s, "%s: sw_if_index %d, next index %d, session %d", tag,
  67               t->sw_if_index, t->next_index, t->session_index);
  68   if (~0 != t->session_index)
  69     {
  70       s = format (s, ", translation result '%U' via %s",
  71                   format_nat_ed_translation_error, t->translation_error,
  72                   t->translation_via_i2of ? "i2of" : "o2if");
  73       s = format (s, "\n  i2of %U", format_nat_6t_flow, &t->i2of);
  74       s = format (s, "\n  o2if %U", format_nat_6t_flow, &t->o2if);
  75     }
  76   if (!t->is_slow_path)
  77     {
  78       if (t->lookup_skipped)
  79         {
  80           s = format (s, "\n lookup skipped - cached session index used");
  81         }
  82       else
  83         {
  84           s = format (s, "\n  search key %U", format_ed_session_kvp,
  85                       &t->search_key);
  86         }
  87     }
  88
  89   return s;
  90 }
  91
  92 static int
  93 next_src_nat (snat_main_t *sm, ip4_header_t *ip, u16 src_port, u16 dst_port,
  94               u32 thread_index, u32 rx_fib_index)
  95 {
  96   clib_bihash_kv_16_8_t kv, value;
  97
  98   init_ed_k (&kv, ip->src_address, src_port, ip->dst_address, dst_port,
  99              rx_fib_index, ip->protocol);
 100   if (!clib_bihash_search_16_8 (&sm->flow_hash, &kv, &value))
 101     return 1;
 102
 103   return 0;
 104 }
 105
 106 static void create_bypass_for_fwd (snat_main_t *sm, vlib_buffer_t *b,
 107                                    snat_session_t *s, ip4_header_t *ip,
 108                                    u32 rx_fib_index, u32 thread_index);
 109
 110 static snat_session_t *create_session_for_static_mapping_ed (
 111   snat_main_t *sm, vlib_buffer_t *b, ip4_address_t i2o_addr, u16 i2o_port,
 112   u32 i2o_fib_index, ip4_address_t o2i_addr, u16 o2i_port, u32 o2i_fib_index,
 113   nat_protocol_t nat_proto, vlib_node_runtime_t *node, u32 rx_fib_index,
 114   u32 thread_index, twice_nat_type_t twice_nat, lb_nat_type_t lb_nat, f64 now,
 115   snat_static_mapping_t *mapping);
 116
 117 static inline u32
 118 icmp_out2in_ed_slow_path (snat_main_t *sm, vlib_buffer_t *b, ip4_header_t *ip,
 119                           icmp46_header_t *icmp, u32 sw_if_index,
 120                           u32 rx_fib_index, vlib_node_runtime_t *node,
 121                           u32 next, f64 now, u32 thread_index,
 122                           snat_session_t **s_p)
 123 {
 124   vlib_main_t *vm = vlib_get_main ();
 125
 126   ip_csum_t sum;
 127   u16 checksum;
 128
 129   snat_session_t *s = 0;
 130   u8 is_addr_only, identity_nat;
 131   ip4_address_t sm_addr;
 132   u16 sm_port;
 133   u32 sm_fib_index;
 134   snat_static_mapping_t *m;
 135   u8 lookup_protocol;
 136   ip4_address_t lookup_saddr, lookup_daddr;
 137   u16 lookup_sport, lookup_dport;
 138
 139   sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
 140   rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 141
 142   if (nat_get_icmp_session_lookup_values (b, ip, &lookup_saddr, &lookup_sport,
 143                                           &lookup_daddr, &lookup_dport,
 144                                           &lookup_protocol))
 145     {
 146       b->error = node->errors[NAT_OUT2IN_ED_ERROR_UNSUPPORTED_PROTOCOL];
 147       next = NAT_NEXT_DROP;
 148       goto out;
 149     }
 150
 151   if (snat_static_mapping_match (
 152         sm, ip->dst_address, lookup_sport, rx_fib_index,
 153         ip_proto_to_nat_proto (ip->protocol), &sm_addr, &sm_port,
 154         &sm_fib_index, 1, &is_addr_only, 0, 0, 0, &identity_nat, &m))
 155     {
 156       // static mapping not matched
 157       if (!sm->forwarding_enabled)
 158         {
 159           /* Don't NAT packet aimed at the intfc address */
 160           if (!is_interface_addr (sm, node, sw_if_index,
 161                                   ip->dst_address.as_u32))
 162             {
 163               b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 164               next = NAT_NEXT_DROP;
 165             }
 166         }
 167       else
 168         {
 169           if (next_src_nat (sm, ip, lookup_sport, lookup_dport, thread_index,
 170                             rx_fib_index))
 171             {
 172               next = NAT_NEXT_IN2OUT_ED_FAST_PATH;
 173             }
 174           else
 175             {
 176               create_bypass_for_fwd (sm, b, s, ip, rx_fib_index, thread_index);
 177             }
 178         }
 179       goto out;
 180     }
 181
 182   if (PREDICT_FALSE (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 183                        ICMP4_echo_reply &&
 184                      (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 185                         ICMP4_echo_request ||
 186                       !is_addr_only)))
 187     {
 188       b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 189       next = NAT_NEXT_DROP;
 190       goto out;
 191     }
 192
 193   if (PREDICT_FALSE (identity_nat))
 194     {
 195       goto out;
 196     }
 197
 198   /* Create session initiated by host from external network */
 199   s = create_session_for_static_mapping_ed (
 200     sm, b, sm_addr, sm_port, sm_fib_index, ip->dst_address, lookup_sport,
 201     rx_fib_index, ip_proto_to_nat_proto (lookup_protocol), node, rx_fib_index,
 202     thread_index, 0, 0, vlib_time_now (vm), m);
 203   if (!s)
 204     next = NAT_NEXT_DROP;
 205
 206   if (PREDICT_TRUE (!ip4_is_fragment (ip)))
 207     {
 208       sum = ip_incremental_checksum_buffer (
 209         vm, b, (u8 *) icmp - (u8 *) vlib_buffer_get_current (b),
 210         ntohs (ip->length) - ip4_header_bytes (ip), 0);
 211       checksum = ~ip_csum_fold (sum);
 212       if (checksum != 0 && checksum != 0xffff)
 213         {
 214           next = NAT_NEXT_DROP;
 215           goto out;
 216         }
 217     }
 218
 219   if (PREDICT_TRUE (next != NAT_NEXT_DROP && s))
 220     {
 221       /* Accounting */
 222       nat44_session_update_counters (
 223         s, now, vlib_buffer_length_in_chain (vm, b), thread_index);
 224       /* Per-user LRU list maintenance */
 225       nat44_session_update_lru (sm, s, thread_index);
 226     }
 227 out:
 228   if (NAT_NEXT_DROP == next && s)
 229     {
 230       nat_ed_session_delete (sm, s, thread_index, 1);
 231       s = 0;
 232     }
 233   *s_p = s;
 234   return next;
 235 }
 236
 237 // allocate exact address based on preference
 238 static_always_inline int
 239 nat_alloc_addr_and_port_exact (snat_address_t * a,
 240                                u32 thread_index,
 241                                nat_protocol_t proto,
 242                                ip4_address_t * addr,
 243                                u16 * port,
 244                                u16 port_per_thread, u32 snat_thread_index)
 245 {
 246   snat_main_t *sm = &snat_main;
 247   u32 portnum;
 248
 249   switch (proto)
 250     {
 251 #define _(N, j, n, s) \
 252     case NAT_PROTOCOL_##N: \
 253       if (a->busy_##n##_ports_per_thread[thread_index] < port_per_thread) \
 254         { \
 255           while (1) \
 256             { \
 257               portnum = (port_per_thread * \
 258                 snat_thread_index) + \
 259                 snat_random_port(0, port_per_thread - 1) + 1024; \
 260               if (a->busy_##n##_port_refcounts[portnum]) \
 261                 continue; \
 262               --a->busy_##n##_port_refcounts[portnum]; \
 263               a->busy_##n##_ports_per_thread[thread_index]++; \
 264               a->busy_##n##_ports++; \
 265               *addr = a->addr; \
 266               *port = clib_host_to_net_u16(portnum); \
 267               return 0; \
 268             } \
 269         } \
 270       break;
 271       foreach_nat_protocol
 272 #undef _
 273         default : nat_elog_info (sm, "unknown protocol");
 274       return 1;
 275     }
 276
 277   /* Totally out of translations to use... */
 278   nat_ipfix_logging_addresses_exhausted (thread_index, 0);
 279   return 1;
 280 }
 281
 282 static_always_inline int
 283 nat44_ed_alloc_outside_addr_and_port (snat_address_t *addresses, u32 fib_index,
 284                                       u32 thread_index, nat_protocol_t proto,
 285                                       ip4_address_t *addr, u16 *port,
 286                                       u16 port_per_thread,
 287                                       u32 snat_thread_index)
 288 {
 289   snat_main_t *sm = &snat_main;
 290   snat_address_t *a, *ga = 0;
 291   u32 portnum;
 292   int i;
 293
 294   for (i = 0; i < vec_len (addresses); i++)
 295     {
 296       a = addresses + i;
 297       switch (proto)
 298         {
 299 #define _(N, j, n, s)                                                         \
 300   case NAT_PROTOCOL_##N:                                                      \
 301     if (a->busy_##n##_ports_per_thread[thread_index] < port_per_thread)       \
 302       {                                                                       \
 303         if (a->fib_index == fib_index)                                        \
 304           {                                                                   \
 305             while (1)                                                         \
 306               {                                                               \
 307                 portnum = (port_per_thread * snat_thread_index) +             \
 308                           snat_random_port (0, port_per_thread - 1) + 1024;   \
 309                 if (a->busy_##n##_port_refcounts[portnum])                    \
 310                   continue;                                                   \
 311                 --a->busy_##n##_port_refcounts[portnum];                      \
 312                 a->busy_##n##_ports_per_thread[thread_index]++;               \
 313                 a->busy_##n##_ports++;                                        \
 314                 *addr = a->addr;                                              \
 315                 *port = clib_host_to_net_u16 (portnum);                       \
 316                 return 0;                                                     \
 317               }                                                               \
 318           }                                                                   \
 319         else if (a->fib_index == ~0)                                          \
 320           {                                                                   \
 321             ga = a;                                                           \
 322           }                                                                   \
 323       }                                                                       \
 324     break;
 325           foreach_nat_protocol
 326 #undef _
 327             default : nat_elog_info (sm, "unknown protocol");
 328           return 1;
 329         }
 330     }
 331
 332   if (ga)
 333     {
 334       a = ga;
 335       switch (proto)
 336         {
 337 #define _(N, j, n, s)                                                         \
 338   case NAT_PROTOCOL_##N:                                                      \
 339     while (1)                                                                 \
 340       {                                                                       \
 341         portnum = (port_per_thread * snat_thread_index) +                     \
 342                   snat_random_port (0, port_per_thread - 1) + 1024;           \
 343         if (a->busy_##n##_port_refcounts[portnum])                            \
 344           continue;                                                           \
 345         ++a->busy_##n##_port_refcounts[portnum];                              \
 346         a->busy_##n##_ports_per_thread[thread_index]++;                       \
 347         a->busy_##n##_ports++;                                                \
 348         *addr = a->addr;                                                      \
 349         *port = clib_host_to_net_u16 (portnum);                               \
 350         return 0;                                                             \
 351       }
 352           break;
 353           foreach_nat_protocol
 354 #undef _
 355             default : nat_elog_info (sm, "unknown protocol");
 356           return 1;
 357         }
 358     }
 359
 360   /* Totally out of translations to use... */
 361   nat_ipfix_logging_addresses_exhausted (thread_index, 0);
 362   return 1;
 363 }
 364
 365 static snat_session_t *
 366 create_session_for_static_mapping_ed (
 367   snat_main_t *sm, vlib_buffer_t *b, ip4_address_t i2o_addr, u16 i2o_port,
 368   u32 i2o_fib_index, ip4_address_t o2i_addr, u16 o2i_port, u32 o2i_fib_index,
 369   nat_protocol_t nat_proto, vlib_node_runtime_t *node, u32 rx_fib_index,
 370   u32 thread_index, twice_nat_type_t twice_nat, lb_nat_type_t lb_nat, f64 now,
 371   snat_static_mapping_t *mapping)
 372 {
 373   snat_session_t *s;
 374   ip4_header_t *ip;
 375   udp_header_t *udp;
 376   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 377
 378   if (PREDICT_FALSE
 379       (nat44_ed_maximum_sessions_exceeded (sm, rx_fib_index, thread_index)))
 380     {
 381       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 382       nat_elog_notice (sm, "maximum sessions exceeded");
 383       return 0;
 384     }
 385
 386   s = nat_ed_session_alloc (sm, thread_index, now, nat_proto);
 387   if (!s)
 388     {
 389       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 390       nat_elog_warn (sm, "create NAT session failed");
 391       return 0;
 392     }
 393
 394   ip = vlib_buffer_get_current (b);
 395   udp = ip4_next_header (ip);
 396
 397   s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 398   s->ext_host_port = nat_proto == NAT_PROTOCOL_ICMP ? 0 : udp->src_port;
 399   s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 400   if (lb_nat)
 401     s->flags |= SNAT_SESSION_FLAG_LOAD_BALANCING;
 402   if (lb_nat == AFFINITY_LB_NAT)
 403     s->flags |= SNAT_SESSION_FLAG_AFFINITY;
 404   s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 405   s->out2in.addr = o2i_addr;
 406   s->out2in.port = o2i_port;
 407   s->out2in.fib_index = o2i_fib_index;
 408   s->in2out.addr = i2o_addr;
 409   s->in2out.port = i2o_port;
 410   s->in2out.fib_index = i2o_fib_index;
 411   s->nat_proto = nat_proto;
 412
 413   if (NAT_PROTOCOL_ICMP == nat_proto)
 414     {
 415       nat_6t_o2i_flow_init (sm, thread_index, s, s->ext_host_addr, o2i_port,
 416                             o2i_addr, o2i_port, o2i_fib_index, ip->protocol);
 417       nat_6t_flow_icmp_id_rewrite_set (&s->o2i, i2o_port);
 418     }
 419   else
 420     {
 421       nat_6t_o2i_flow_init (sm, thread_index, s, s->ext_host_addr,
 422                             s->ext_host_port, o2i_addr, o2i_port,
 423                             o2i_fib_index, ip->protocol);
 424       nat_6t_flow_dport_rewrite_set (&s->o2i, i2o_port);
 425     }
 426   nat_6t_flow_daddr_rewrite_set (&s->o2i, i2o_addr.as_u32);
 427   nat_6t_flow_txfib_rewrite_set (&s->o2i, i2o_fib_index);
 428
 429   if (nat_ed_ses_o2i_flow_hash_add_del (sm, thread_index, s, 1))
 430     {
 431       b->error = node->errors[NAT_OUT2IN_ED_ERROR_HASH_ADD_FAILED];
 432       nat_ed_session_delete (sm, s, thread_index, 1);
 433       nat_elog_warn (sm, "out2in flow hash add failed");
 434       return 0;
 435     }
 436
 437   if (twice_nat == TWICE_NAT || (twice_nat == TWICE_NAT_SELF &&
 438                                  ip->src_address.as_u32 == i2o_addr.as_u32))
 439     {
 440       int rc = 0;
 441       snat_address_t *filter = 0;
 442
 443       // if exact address is specified use this address
 444       if (is_exact_address (mapping))
 445         {
 446           snat_address_t *ap;
 447           vec_foreach (ap, sm->twice_nat_addresses)
 448           {
 449             if (mapping->pool_addr.as_u32 == ap->addr.as_u32)
 450               {
 451                 filter = ap;
 452                 break;
 453               }
 454           }
 455         }
 456
 457       if (filter)
 458         {
 459           rc = nat_alloc_addr_and_port_exact (filter,
 460                                               thread_index,
 461                                               nat_proto,
 462                                               &s->ext_host_nat_addr,
 463                                               &s->ext_host_nat_port,
 464                                               sm->port_per_thread,
 465                                               tsm->snat_thread_index);
 466           s->flags |= SNAT_SESSION_FLAG_EXACT_ADDRESS;
 467         }
 468       else
 469         {
 470           rc = nat44_ed_alloc_outside_addr_and_port (
 471             sm->twice_nat_addresses, 0, thread_index, nat_proto,
 472             &s->ext_host_nat_addr, &s->ext_host_nat_port, sm->port_per_thread,
 473             tsm->snat_thread_index);
 474         }
 475
 476       if (rc)
 477         {
 478           b->error = node->errors[NAT_OUT2IN_ED_ERROR_OUT_OF_PORTS];
 479           if (nat_ed_ses_o2i_flow_hash_add_del (sm, thread_index, s, 0))
 480             {
 481               nat_elog_warn (sm, "out2in flow hash del failed");
 482             }
 483           snat_free_outside_address_and_port (
 484             sm->twice_nat_addresses, thread_index, &s->ext_host_nat_addr,
 485             s->ext_host_nat_port, s->nat_proto);
 486           nat_ed_session_delete (sm, s, thread_index, 1);
 487           return 0;
 488         }
 489
 490       s->flags |= SNAT_SESSION_FLAG_TWICE_NAT;
 491
 492       nat_6t_flow_saddr_rewrite_set (&s->o2i, s->ext_host_nat_addr.as_u32);
 493       if (NAT_PROTOCOL_ICMP == nat_proto)
 494         {
 495           nat_6t_flow_icmp_id_rewrite_set (&s->o2i, s->ext_host_nat_port);
 496         }
 497       else
 498         {
 499           nat_6t_flow_sport_rewrite_set (&s->o2i, s->ext_host_nat_port);
 500         }
 501
 502       nat_6t_l3_l4_csum_calc (&s->o2i);
 503
 504       nat_6t_i2o_flow_init (sm, thread_index, s, i2o_addr, i2o_port,
 505                             s->ext_host_nat_addr, s->ext_host_nat_port,
 506                             i2o_fib_index, ip->protocol);
 507       nat_6t_flow_daddr_rewrite_set (&s->i2o, s->ext_host_addr.as_u32);
 508       if (NAT_PROTOCOL_ICMP == nat_proto)
 509         {
 510           nat_6t_flow_icmp_id_rewrite_set (&s->i2o, s->ext_host_port);
 511         }
 512       else
 513         {
 514           nat_6t_flow_dport_rewrite_set (&s->i2o, s->ext_host_port);
 515         }
 516     }
 517   else
 518     {
 519       if (NAT_PROTOCOL_ICMP == nat_proto)
 520         {
 521           nat_6t_i2o_flow_init (sm, thread_index, s, i2o_addr, i2o_port,
 522                                 s->ext_host_addr, i2o_port, i2o_fib_index,
 523                                 ip->protocol);
 524         }
 525       else
 526         {
 527           nat_6t_i2o_flow_init (sm, thread_index, s, i2o_addr, i2o_port,
 528                                 s->ext_host_addr, s->ext_host_port,
 529                                 i2o_fib_index, ip->protocol);
 530         }
 531     }
 532
 533   nat_6t_flow_saddr_rewrite_set (&s->i2o, o2i_addr.as_u32);
 534   if (NAT_PROTOCOL_ICMP == nat_proto)
 535     {
 536       nat_6t_flow_icmp_id_rewrite_set (&s->i2o, o2i_port);
 537     }
 538   else
 539     {
 540       nat_6t_flow_sport_rewrite_set (&s->i2o, o2i_port);
 541     }
 542
 543   if (nat_ed_ses_i2o_flow_hash_add_del (sm, thread_index, s, 1))
 544     {
 545       nat_elog_notice (sm, "in2out flow hash add failed");
 546       if (nat_ed_ses_o2i_flow_hash_add_del (sm, thread_index, s, 0))
 547         {
 548           nat_elog_warn (sm, "out2in flow hash del failed");
 549         }
 550       nat_ed_session_delete (sm, s, thread_index, 1);
 551       return 0;
 552     }
 553
 554   nat_ipfix_logging_nat44_ses_create (thread_index,
 555                                       s->in2out.addr.as_u32,
 556                                       s->out2in.addr.as_u32,
 557                                       s->nat_proto,
 558                                       s->in2out.port,
 559                                       s->out2in.port, s->in2out.fib_index);
 560
 561   nat_syslog_nat44_sadd (0, s->in2out.fib_index, &s->in2out.addr,
 562                          s->in2out.port, &s->ext_host_nat_addr,
 563                          s->ext_host_nat_port, &s->out2in.addr, s->out2in.port,
 564                          &s->ext_host_addr, s->ext_host_port, s->nat_proto,
 565                          is_twice_nat_session (s));
 566
 567   per_vrf_sessions_register_session (s, thread_index);
 568
 569   return s;
 570 }
 571
 572 static void
 573 create_bypass_for_fwd (snat_main_t *sm, vlib_buffer_t *b, snat_session_t *s,
 574                        ip4_header_t *ip, u32 rx_fib_index, u32 thread_index)
 575 {
 576   clib_bihash_kv_16_8_t kv, value;
 577   udp_header_t *udp;
 578   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 579   vlib_main_t *vm = vlib_get_main ();
 580   f64 now = vlib_time_now (vm);
 581   u16 lookup_sport, lookup_dport;
 582   u8 lookup_protocol;
 583   ip4_address_t lookup_saddr, lookup_daddr;
 584
 585   if (ip->protocol == IP_PROTOCOL_ICMP)
 586     {
 587       if (nat_get_icmp_session_lookup_values (b, ip, &lookup_saddr,
 588                                               &lookup_sport, &lookup_daddr,
 589                                               &lookup_dport, &lookup_protocol))
 590         return;
 591     }
 592   else
 593     {
 594       if (ip->protocol == IP_PROTOCOL_UDP || ip->protocol == IP_PROTOCOL_TCP)
 595         {
 596           udp = ip4_next_header (ip);
 597           lookup_sport = udp->dst_port;
 598           lookup_dport = udp->src_port;
 599         }
 600       else
 601         {
 602           lookup_sport = 0;
 603           lookup_dport = 0;
 604         }
 605       lookup_saddr.as_u32 = ip->dst_address.as_u32;
 606       lookup_daddr.as_u32 = ip->src_address.as_u32;
 607       lookup_protocol = ip->protocol;
 608     }
 609
 610   init_ed_k (&kv, lookup_saddr, lookup_sport, lookup_daddr, lookup_dport,
 611              rx_fib_index, lookup_protocol);
 612
 613   if (!clib_bihash_search_16_8 (&sm->flow_hash, &kv, &value))
 614     {
 615       ASSERT (thread_index == ed_value_get_thread_index (&value));
 616       s =
 617         pool_elt_at_index (tsm->sessions,
 618                            ed_value_get_session_index (&value));
 619     }
 620   else if (ip->protocol == IP_PROTOCOL_ICMP &&
 621            icmp_type_is_error_message
 622            (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags))
 623     {
 624       return;
 625     }
 626   else
 627     {
 628       u32 proto;
 629
 630       if (PREDICT_FALSE
 631           (nat44_ed_maximum_sessions_exceeded
 632            (sm, rx_fib_index, thread_index)))
 633         return;
 634
 635       s = nat_ed_session_alloc (sm, thread_index, now, ip->protocol);
 636       if (!s)
 637         {
 638           nat_elog_warn (sm, "create NAT session failed");
 639           return;
 640         }
 641
 642       proto = ip_proto_to_nat_proto (ip->protocol);
 643
 644       s->ext_host_addr = ip->src_address;
 645       s->ext_host_port = lookup_dport;
 646       s->flags |= SNAT_SESSION_FLAG_FWD_BYPASS;
 647       s->out2in.addr = ip->dst_address;
 648       s->out2in.port = lookup_sport;
 649       s->nat_proto = proto;
 650       if (proto == NAT_PROTOCOL_OTHER)
 651         {
 652           s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 653           s->out2in.port = ip->protocol;
 654         }
 655       s->out2in.fib_index = rx_fib_index;
 656       s->in2out.addr = s->out2in.addr;
 657       s->in2out.port = s->out2in.port;
 658       s->in2out.fib_index = s->out2in.fib_index;
 659
 660       nat_6t_i2o_flow_init (sm, thread_index, s, ip->dst_address, lookup_sport,
 661                             ip->src_address, lookup_dport, rx_fib_index,
 662                             ip->protocol);
 663       nat_6t_flow_txfib_rewrite_set (&s->i2o, rx_fib_index);
 664       if (nat_ed_ses_i2o_flow_hash_add_del (sm, thread_index, s, 1))
 665         {
 666           nat_elog_notice (sm, "in2out flow add failed");
 667           nat_ed_session_delete (sm, s, thread_index, 1);
 668           return;
 669         }
 670
 671       per_vrf_sessions_register_session (s, thread_index);
 672     }
 673
 674   if (ip->protocol == IP_PROTOCOL_TCP)
 675     {
 676       tcp_header_t *tcp = ip4_next_header (ip);
 677       nat44_set_tcp_session_state_o2i (sm, now, s, tcp->flags,
 678                                        tcp->ack_number, tcp->seq_number,
 679                                        thread_index);
 680     }
 681
 682   /* Accounting */
 683   nat44_session_update_counters (s, now, 0, thread_index);
 684   /* Per-user LRU list maintenance */
 685   nat44_session_update_lru (sm, s, thread_index);
 686 }
 687
 688 static snat_session_t *
 689 nat44_ed_out2in_slowpath_unknown_proto (snat_main_t *sm, vlib_buffer_t *b,
 690                                         ip4_header_t *ip, u32 rx_fib_index,
 691                                         u32 thread_index, f64 now,
 692                                         vlib_main_t *vm,
 693                                         vlib_node_runtime_t *node)
 694 {
 695   clib_bihash_kv_8_8_t kv, value;
 696   snat_static_mapping_t *m;
 697   snat_session_t *s;
 698
 699   if (PREDICT_FALSE (
 700         nat44_ed_maximum_sessions_exceeded (sm, rx_fib_index, thread_index)))
 701     {
 702       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 703       nat_elog_notice (sm, "maximum sessions exceeded");
 704       return 0;
 705     }
 706
 707   init_nat_k (&kv, ip->dst_address, 0, 0, 0);
 708   if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
 709     {
 710       b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 711       return 0;
 712     }
 713
 714   m = pool_elt_at_index (sm->static_mappings, value.value);
 715
 716   /* Create a new session */
 717   s = nat_ed_session_alloc (sm, thread_index, now, ip->protocol);
 718   if (!s)
 719     {
 720       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 721       nat_elog_warn (sm, "create NAT session failed");
 722       return 0;
 723     }
 724
 725   s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 726   s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 727   s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 728   s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 729   s->out2in.addr.as_u32 = ip->dst_address.as_u32;
 730   s->out2in.fib_index = rx_fib_index;
 731   s->in2out.addr.as_u32 = m->local_addr.as_u32;
 732   s->in2out.fib_index = m->fib_index;
 733   s->in2out.port = s->out2in.port = ip->protocol;
 734
 735   nat_6t_o2i_flow_init (sm, thread_index, s, ip->dst_address, 0,
 736                         ip->src_address, 0, m->fib_index, ip->protocol);
 737   nat_6t_flow_saddr_rewrite_set (&s->i2o, ip->dst_address.as_u32);
 738   if (nat_ed_ses_i2o_flow_hash_add_del (sm, thread_index, s, 1))
 739     {
 740       nat_elog_notice (sm, "in2out key add failed");
 741       nat_ed_session_delete (sm, s, thread_index, 1);
 742       return NULL;
 743     }
 744
 745   nat_6t_o2i_flow_init (sm, thread_index, s, ip->src_address, 0,
 746                         ip->dst_address, 0, rx_fib_index, ip->protocol);
 747   nat_6t_flow_daddr_rewrite_set (&s->o2i, m->local_addr.as_u32);
 748   nat_6t_flow_txfib_rewrite_set (&s->o2i, m->fib_index);
 749   if (nat_ed_ses_o2i_flow_hash_add_del (sm, thread_index, s, 1))
 750     {
 751       nat_elog_notice (sm, "out2in flow hash add failed");
 752       nat_ed_session_delete (sm, s, thread_index, 1);
 753       return NULL;
 754     }
 755
 756   per_vrf_sessions_register_session (s, thread_index);
 757
 758   /* Accounting */
 759   nat44_session_update_counters (s, now, vlib_buffer_length_in_chain (vm, b),
 760                                  thread_index);
 761   /* Per-user LRU list maintenance */
 762   nat44_session_update_lru (sm, s, thread_index);
 763
 764   return s;
 765 }
 766
 767 static inline uword
 768 nat44_ed_out2in_fast_path_node_fn_inline (vlib_main_t * vm,
 769                                           vlib_node_runtime_t * node,
 770                                           vlib_frame_t * frame,
 771                                           int is_multi_worker)
 772 {
 773   u32 n_left_from, *from;
 774   snat_main_t *sm = &snat_main;
 775   f64 now = vlib_time_now (vm);
 776   u32 thread_index = vm->thread_index;
 777   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 778
 779   from = vlib_frame_vector_args (frame);
 780   n_left_from = frame->n_vectors;
 781
 782   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b = bufs;
 783   u16 nexts[VLIB_FRAME_SIZE], *next = nexts;
 784   vlib_get_buffers (vm, from, b, n_left_from);
 785
 786   while (n_left_from > 0)
 787     {
 788       vlib_buffer_t *b0;
 789       u32 sw_if_index0, rx_fib_index0;
 790       nat_protocol_t proto0;
 791       ip4_header_t *ip0;
 792       snat_session_t *s0 = 0;
 793       clib_bihash_kv_16_8_t kv0, value0;
 794       nat_translation_error_e translation_error = NAT_ED_TRNSL_ERR_SUCCESS;
 795       nat_6t_flow_t *f = 0;
 796       nat_6t_t lookup;
 797       int lookup_skipped = 0;
 798
 799       b0 = *b;
 800       b++;
 801
 802       /* Prefetch next iteration. */
 803       if (PREDICT_TRUE (n_left_from >= 2))
 804         {
 805           vlib_buffer_t *p2;
 806
 807           p2 = *b;
 808
 809           vlib_prefetch_buffer_header (p2, LOAD);
 810
 811           CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, LOAD);
 812         }
 813
 814       next[0] = vnet_buffer2 (b0)->nat.arc_next;
 815
 816       lookup.sport = vnet_buffer (b0)->ip.reass.l4_src_port;
 817       lookup.dport = vnet_buffer (b0)->ip.reass.l4_dst_port;
 818
 819       vnet_buffer (b0)->snat.flags = 0;
 820       ip0 = vlib_buffer_get_current (b0);
 821
 822       sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 823       rx_fib_index0 =
 824         fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4, sw_if_index0);
 825
 826       lookup.fib_index = rx_fib_index0;
 827
 828       if (PREDICT_FALSE (ip0->ttl == 1))
 829         {
 830           vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 831           icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 832                                        ICMP4_time_exceeded_ttl_exceeded_in_transit,
 833                                        0);
 834           next[0] = NAT_NEXT_ICMP_ERROR;
 835           goto trace0;
 836         }
 837
 838       proto0 = ip_proto_to_nat_proto (ip0->protocol);
 839
 840       if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
 841         {
 842           if (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
 843                 ICMP4_echo_request &&
 844               vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
 845                 ICMP4_echo_reply &&
 846               !icmp_type_is_error_message (
 847                 vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags))
 848             {
 849               b0->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 850               next[0] = NAT_NEXT_DROP;
 851               goto trace0;
 852             }
 853           int err = nat_get_icmp_session_lookup_values (
 854             b0, ip0, &lookup.saddr, &lookup.sport, &lookup.daddr,
 855             &lookup.dport, &lookup.proto);
 856           if (err != 0)
 857             {
 858               b0->error = node->errors[err];
 859               next[0] = NAT_NEXT_DROP;
 860               goto trace0;
 861             }
 862         }
 863       else
 864         {
 865           lookup.saddr.as_u32 = ip0->src_address.as_u32;
 866           lookup.daddr.as_u32 = ip0->dst_address.as_u32;
 867           lookup.proto = ip0->protocol;
 868         }
 869
 870       /* there might be a stashed index in vnet_buffer2 from handoff or
 871        * classify node, see if it can be used */
 872       if (is_multi_worker &&
 873           !pool_is_free_index (tsm->sessions,
 874                                vnet_buffer2 (b0)->nat.cached_session_index))
 875         {
 876           s0 = pool_elt_at_index (tsm->sessions,
 877                                   vnet_buffer2 (b0)->nat.cached_session_index);
 878           if (PREDICT_TRUE (nat_6t_t_eq (&s0->o2i.match, &lookup)) ||
 879               (s0->flags & SNAT_SESSION_FLAG_TWICE_NAT &&
 880                nat_6t_t_eq (&s0->i2o.match, &lookup)))
 881             {
 882               /* yes, this is the droid we're looking for */
 883               lookup_skipped = 1;
 884               goto skip_lookup;
 885             }
 886           s0 = NULL;
 887         }
 888
 889       init_ed_k (&kv0, lookup.saddr, lookup.sport, lookup.daddr, lookup.dport,
 890                  lookup.fib_index, lookup.proto);
 891
 892       // lookup flow
 893       if (clib_bihash_search_16_8 (&sm->flow_hash, &kv0, &value0))
 894         {
 895           // flow does not exist go slow path
 896           next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 897           goto trace0;
 898         }
 899       ASSERT (thread_index == ed_value_get_thread_index (&value0));
 900       s0 =
 901         pool_elt_at_index (tsm->sessions,
 902                            ed_value_get_session_index (&value0));
 903     skip_lookup:
 904
 905       if (PREDICT_FALSE (per_vrf_sessions_is_expired (s0, thread_index)))
 906         {
 907           // session is closed, go slow path
 908           nat_free_session_data (sm, s0, thread_index, 0);
 909           nat_ed_session_delete (sm, s0, thread_index, 1);
 910           next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 911           goto trace0;
 912         }
 913
 914       if (s0->tcp_closed_timestamp)
 915         {
 916           if (now >= s0->tcp_closed_timestamp)
 917             {
 918               // session is closed, go slow path, freed in slow path
 919               next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 920             }
 921           else
 922             {
 923               // session in transitory timeout, drop
 924               b0->error = node->errors[NAT_OUT2IN_ED_ERROR_TCP_CLOSED];
 925               next[0] = NAT_NEXT_DROP;
 926             }
 927           goto trace0;
 928         }
 929
 930       // drop if session expired
 931       u64 sess_timeout_time;
 932       sess_timeout_time =
 933         s0->last_heard + (f64) nat44_session_get_timeout (sm, s0);
 934       if (now >= sess_timeout_time)
 935         {
 936           // session is closed, go slow path
 937           nat_free_session_data (sm, s0, thread_index, 0);
 938           nat_ed_session_delete (sm, s0, thread_index, 1);
 939           next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 940           goto trace0;
 941         }
 942
 943       if (nat_6t_t_eq (&s0->o2i.match, &lookup))
 944         {
 945           f = &s0->o2i;
 946         }
 947       else if (s0->flags & SNAT_SESSION_FLAG_TWICE_NAT &&
 948                nat_6t_t_eq (&s0->i2o.match, &lookup))
 949         {
 950           f = &s0->i2o;
 951         }
 952       else
 953         {
 954           /*
 955            * Send DHCP packets to the ipv4 stack, or we won't
 956            * be able to use dhcp client on the outside interface
 957            */
 958           if (PREDICT_FALSE (
 959                 proto0 == NAT_PROTOCOL_UDP &&
 960                 (vnet_buffer (b0)->ip.reass.l4_dst_port ==
 961                  clib_host_to_net_u16 (UDP_DST_PORT_dhcp_to_client))))
 962             {
 963               goto trace0;
 964             }
 965
 966           if (!sm->forwarding_enabled)
 967             {
 968               b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 969               next[0] = NAT_NEXT_DROP;
 970               goto trace0;
 971             }
 972           else
 973             {
 974               if (nat_6t_t_eq (&s0->i2o.match, &lookup))
 975                 {
 976                   f = &s0->i2o;
 977                 }
 978               else
 979                 {
 980                   // FIXME TODO bypass ???
 981                   //  create_bypass_for_fwd (sm, b0, s0, ip0, rx_fib_index0,
 982                   //                       thread_index);
 983                   translation_error = NAT_ED_TRNSL_ERR_FLOW_MISMATCH;
 984                   nat_free_session_data (sm, s0, thread_index, 0);
 985                   nat_ed_session_delete (sm, s0, thread_index, 1);
 986                   next[0] = NAT_NEXT_DROP;
 987                   goto trace0;
 988                 }
 989             }
 990         }
 991
 992       if (NAT_ED_TRNSL_ERR_SUCCESS !=
 993           (translation_error = nat_6t_flow_buf_translate (
 994              sm, b0, ip0, f, proto0, 0 /* is_output_feature */)))
 995         {
 996           next[0] = NAT_NEXT_DROP;
 997           goto trace0;
 998         }
 999
1000       switch (proto0)
1001         {
1002         case NAT_PROTOCOL_TCP:
1003           vlib_increment_simple_counter (&sm->counters.fastpath.out2in.tcp,
1004                                          thread_index, sw_if_index0, 1);
1005           nat44_set_tcp_session_state_o2i (sm, now, s0,
1006                                            vnet_buffer (b0)->ip.
1007                                            reass.icmp_type_or_tcp_flags,
1008                                            vnet_buffer (b0)->ip.
1009                                            reass.tcp_ack_number,
1010                                            vnet_buffer (b0)->ip.
1011                                            reass.tcp_seq_number,
1012                                            thread_index);
1013           break;
1014         case NAT_PROTOCOL_UDP:
1015           vlib_increment_simple_counter (&sm->counters.fastpath.out2in.udp,
1016                                          thread_index, sw_if_index0, 1);
1017           break;
1018         case NAT_PROTOCOL_ICMP:
1019           vlib_increment_simple_counter (&sm->counters.fastpath.out2in.icmp,
1020                                          thread_index, sw_if_index0, 1);
1021           break;
1022         case NAT_PROTOCOL_OTHER:
1023           vlib_increment_simple_counter (&sm->counters.fastpath.out2in.other,
1024                                          thread_index, sw_if_index0, 1);
1025           break;
1026         }
1027
1028       /* Accounting */
1029       nat44_session_update_counters (s0, now,
1030                                      vlib_buffer_length_in_chain (vm, b0),
1031                                      thread_index);
1032       /* Per-user LRU list maintenance */
1033       nat44_session_update_lru (sm, s0, thread_index);
1034
1035     trace0:
1036       if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1037                          && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1038         {
1039           nat44_ed_out2in_trace_t *t =
1040             vlib_add_trace (vm, node, b0, sizeof (*t));
1041           t->sw_if_index = sw_if_index0;
1042           t->next_index = next[0];
1043           t->is_slow_path = 0;
1044           t->translation_error = translation_error;
1045           clib_memcpy (&t->search_key, &kv0, sizeof (t->search_key));
1046           t->lookup_skipped = lookup_skipped;
1047
1048           if (s0)
1049             {
1050               t->session_index = s0 - tsm->sessions;
1051               clib_memcpy (&t->i2of, &s0->i2o, sizeof (t->i2of));
1052               clib_memcpy (&t->o2if, &s0->o2i, sizeof (t->o2if));
1053               t->translation_via_i2of = (&s0->i2o == f);
1054             }
1055           else
1056             {
1057               t->session_index = ~0;
1058             }
1059         }
1060
1061       if (next[0] == NAT_NEXT_DROP)
1062         {
1063           vlib_increment_simple_counter (&sm->counters.fastpath.out2in.drops,
1064                                          thread_index, sw_if_index0, 1);
1065         }
1066
1067       n_left_from--;
1068       next++;
1069     }
1070
1071   vlib_buffer_enqueue_to_next (vm, node, from, (u16 *) nexts,
1072                                frame->n_vectors);
1073   return frame->n_vectors;
1074 }
1075
1076 static inline uword
1077 nat44_ed_out2in_slow_path_node_fn_inline (vlib_main_t * vm,
1078                                           vlib_node_runtime_t * node,
1079                                           vlib_frame_t * frame)
1080 {
1081   u32 n_left_from, *from;
1082   snat_main_t *sm = &snat_main;
1083   f64 now = vlib_time_now (vm);
1084   u32 thread_index = vm->thread_index;
1085   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
1086   snat_static_mapping_t *m;
1087
1088   from = vlib_frame_vector_args (frame);
1089   n_left_from = frame->n_vectors;
1090
1091   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b = bufs;
1092   u16 nexts[VLIB_FRAME_SIZE], *next = nexts;
1093   vlib_get_buffers (vm, from, b, n_left_from);
1094
1095   while (n_left_from > 0)
1096     {
1097       vlib_buffer_t *b0;
1098       u32 sw_if_index0, rx_fib_index0;
1099       nat_protocol_t proto0;
1100       ip4_header_t *ip0;
1101       udp_header_t *udp0;
1102       icmp46_header_t *icmp0;
1103       snat_session_t *s0 = 0;
1104       clib_bihash_kv_16_8_t kv0, value0;
1105       lb_nat_type_t lb_nat0;
1106       twice_nat_type_t twice_nat0;
1107       u8 identity_nat0;
1108       ip4_address_t sm_addr;
1109       u16 sm_port;
1110       u32 sm_fib_index;
1111       nat_translation_error_e translation_error = NAT_ED_TRNSL_ERR_SUCCESS;
1112
1113       b0 = *b;
1114       next[0] = vnet_buffer2 (b0)->nat.arc_next;
1115
1116       vnet_buffer (b0)->snat.flags = 0;
1117       ip0 = vlib_buffer_get_current (b0);
1118
1119       sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1120       rx_fib_index0 =
1121         fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4, sw_if_index0);
1122
1123       if (PREDICT_FALSE (ip0->ttl == 1))
1124         {
1125           vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1126           icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1127                                        ICMP4_time_exceeded_ttl_exceeded_in_transit,
1128                                        0);
1129           next[0] = NAT_NEXT_ICMP_ERROR;
1130           goto trace0;
1131         }
1132
1133       udp0 = ip4_next_header (ip0);
1134       icmp0 = (icmp46_header_t *) udp0;
1135       proto0 = ip_proto_to_nat_proto (ip0->protocol);
1136
1137       if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
1138         {
1139           s0 = nat44_ed_out2in_slowpath_unknown_proto (
1140             sm, b0, ip0, rx_fib_index0, thread_index, now, vm, node);
1141           if (!sm->forwarding_enabled)
1142             {
1143               if (!s0)
1144                 next[0] = NAT_NEXT_DROP;
1145             }
1146           if (NAT_NEXT_DROP != next[0] &&
1147               NAT_ED_TRNSL_ERR_SUCCESS !=
1148                 (translation_error = nat_6t_flow_buf_translate (
1149                    sm, b0, ip0, &s0->o2i, proto0, 0 /* is_output_feature */)))
1150             {
1151               goto trace0;
1152             }
1153
1154           vlib_increment_simple_counter (&sm->counters.slowpath.out2in.other,
1155                                          thread_index, sw_if_index0, 1);
1156           goto trace0;
1157         }
1158
1159       if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
1160         {
1161           next[0] = icmp_out2in_ed_slow_path
1162             (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1163              next[0], now, thread_index, &s0);
1164
1165           if (NAT_NEXT_DROP != next[0] && s0 &&
1166               NAT_ED_TRNSL_ERR_SUCCESS !=
1167                 (translation_error = nat_6t_flow_buf_translate (
1168                    sm, b0, ip0, &s0->o2i, proto0, 0 /* is_output_feature */)))
1169             {
1170               goto trace0;
1171             }
1172
1173           vlib_increment_simple_counter (&sm->counters.slowpath.out2in.icmp,
1174                                          thread_index, sw_if_index0, 1);
1175           goto trace0;
1176         }
1177
1178       init_ed_k (&kv0, ip0->src_address,
1179                  vnet_buffer (b0)->ip.reass.l4_src_port, ip0->dst_address,
1180                  vnet_buffer (b0)->ip.reass.l4_dst_port, rx_fib_index0,
1181                  ip0->protocol);
1182
1183       s0 = NULL;
1184       if (!clib_bihash_search_16_8 (&sm->flow_hash, &kv0, &value0))
1185         {
1186           ASSERT (thread_index == ed_value_get_thread_index (&value0));
1187           s0 =
1188             pool_elt_at_index (tsm->sessions,
1189                                ed_value_get_session_index (&value0));
1190
1191           if (s0->tcp_closed_timestamp && now >= s0->tcp_closed_timestamp)
1192             {
1193               nat_free_session_data (sm, s0, thread_index, 0);
1194               nat_ed_session_delete (sm, s0, thread_index, 1);
1195               s0 = NULL;
1196             }
1197         }
1198
1199       if (!s0)
1200         {
1201           /* Try to match static mapping by external address and port,
1202              destination address and port in packet */
1203
1204           if (snat_static_mapping_match
1205               (sm, ip0->dst_address,
1206                vnet_buffer (b0)->ip.reass.l4_dst_port, rx_fib_index0,
1207                proto0, &sm_addr, &sm_port, &sm_fib_index, 1, 0,
1208                &twice_nat0, &lb_nat0, &ip0->src_address, &identity_nat0, &m))
1209             {
1210               /*
1211                * Send DHCP packets to the ipv4 stack, or we won't
1212                * be able to use dhcp client on the outside interface
1213                */
1214               if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_UDP
1215                                  && (vnet_buffer (b0)->ip.reass.l4_dst_port ==
1216                                      clib_host_to_net_u16
1217                                      (UDP_DST_PORT_dhcp_to_client))))
1218                 {
1219                   goto trace0;
1220                 }
1221
1222               if (!sm->forwarding_enabled)
1223                 {
1224                   b0->error =
1225                     node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
1226                   next[0] = NAT_NEXT_DROP;
1227                 }
1228               else
1229                 {
1230                   if (next_src_nat
1231                       (sm, ip0, vnet_buffer (b0)->ip.reass.l4_src_port,
1232                        vnet_buffer (b0)->ip.reass.l4_dst_port,
1233                        thread_index, rx_fib_index0))
1234                     {
1235                       next[0] = NAT_NEXT_IN2OUT_ED_FAST_PATH;
1236                     }
1237                   else
1238                     {
1239                       create_bypass_for_fwd (sm, b0, s0, ip0, rx_fib_index0,
1240                                              thread_index);
1241                     }
1242                 }
1243               goto trace0;
1244             }
1245
1246           if (PREDICT_FALSE (identity_nat0))
1247             goto trace0;
1248
1249           if ((proto0 == NAT_PROTOCOL_TCP)
1250               && !tcp_flags_is_init (vnet_buffer (b0)->ip.
1251                                      reass.icmp_type_or_tcp_flags))
1252             {
1253               b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
1254               next[0] = NAT_NEXT_DROP;
1255               goto trace0;
1256             }
1257
1258           /* Create session initiated by host from external network */
1259           s0 = create_session_for_static_mapping_ed (sm, b0,
1260                                                      sm_addr, sm_port,
1261                                                      sm_fib_index,
1262                                                      ip0->dst_address,
1263                                                      vnet_buffer (b0)->
1264                                                      ip.reass.l4_dst_port,
1265                                                      rx_fib_index0, proto0,
1266                                                      node, rx_fib_index0,
1267                                                      thread_index, twice_nat0,
1268                                                      lb_nat0, now, m);
1269           if (!s0)
1270             {
1271               next[0] = NAT_NEXT_DROP;
1272               goto trace0;
1273             }
1274         }
1275
1276       if (NAT_ED_TRNSL_ERR_SUCCESS !=
1277           (translation_error = nat_6t_flow_buf_translate (
1278              sm, b0, ip0, &s0->o2i, proto0, 0 /* is_output_feature */)))
1279         {
1280           next[0] = NAT_NEXT_DROP;
1281           goto trace0;
1282         }
1283
1284       if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
1285         {
1286           vlib_increment_simple_counter (&sm->counters.slowpath.out2in.tcp,
1287                                          thread_index, sw_if_index0, 1);
1288           nat44_set_tcp_session_state_o2i (sm, now, s0,
1289                                            vnet_buffer (b0)->ip.
1290                                            reass.icmp_type_or_tcp_flags,
1291                                            vnet_buffer (b0)->ip.
1292                                            reass.tcp_ack_number,
1293                                            vnet_buffer (b0)->ip.
1294                                            reass.tcp_seq_number,
1295                                            thread_index);
1296         }
1297       else
1298         {
1299           vlib_increment_simple_counter (&sm->counters.slowpath.out2in.udp,
1300                                          thread_index, sw_if_index0, 1);
1301         }
1302
1303       /* Accounting */
1304       nat44_session_update_counters (s0, now,
1305                                      vlib_buffer_length_in_chain (vm, b0),
1306                                      thread_index);
1307       /* Per-user LRU list maintenance */
1308       nat44_session_update_lru (sm, s0, thread_index);
1309
1310     trace0:
1311       if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1312                          && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1313         {
1314           nat44_ed_out2in_trace_t *t =
1315             vlib_add_trace (vm, node, b0, sizeof (*t));
1316           t->sw_if_index = sw_if_index0;
1317           t->next_index = next[0];
1318           t->is_slow_path = 1;
1319           t->translation_error = translation_error;
1320           clib_memcpy (&t->search_key, &kv0, sizeof (t->search_key));
1321
1322           if (s0)
1323             {
1324               t->session_index = s0 - tsm->sessions;
1325               clib_memcpy (&t->i2of, &s0->i2o, sizeof (t->i2of));
1326               clib_memcpy (&t->o2if, &s0->o2i, sizeof (t->o2if));
1327             }
1328           else
1329             {
1330               t->session_index = ~0;
1331             }
1332         }
1333
1334       if (next[0] == NAT_NEXT_DROP)
1335         {
1336           vlib_increment_simple_counter (&sm->counters.slowpath.out2in.drops,
1337                                          thread_index, sw_if_index0, 1);
1338         }
1339
1340       n_left_from--;
1341       next++;
1342       b++;
1343     }
1344
1345   vlib_buffer_enqueue_to_next (vm, node, from, (u16 *) nexts,
1346                                frame->n_vectors);
1347
1348   return frame->n_vectors;
1349 }
1350
1351 VLIB_NODE_FN (nat44_ed_out2in_node) (vlib_main_t * vm,
1352                                      vlib_node_runtime_t * node,
1353                                      vlib_frame_t * frame)
1354 {
1355   if (snat_main.num_workers > 1)
1356     {
1357       return nat44_ed_out2in_fast_path_node_fn_inline (vm, node, frame, 1);
1358     }
1359   else
1360     {
1361       return nat44_ed_out2in_fast_path_node_fn_inline (vm, node, frame, 0);
1362     }
1363 }
1364
1365 /* *INDENT-OFF* */
1366 VLIB_REGISTER_NODE (nat44_ed_out2in_node) = {
1367   .name = "nat44-ed-out2in",
1368   .vector_size = sizeof (u32),
1369   .sibling_of = "nat-default",
1370   .format_trace = format_nat44_ed_out2in_trace,
1371   .type = VLIB_NODE_TYPE_INTERNAL,
1372   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1373   .error_strings = nat_out2in_ed_error_strings,
1374   .runtime_data_bytes = sizeof (snat_runtime_t),
1375 };
1376 /* *INDENT-ON* */
1377
1378 VLIB_NODE_FN (nat44_ed_out2in_slowpath_node) (vlib_main_t * vm,
1379                                               vlib_node_runtime_t * node,
1380                                               vlib_frame_t * frame)
1381 {
1382   return nat44_ed_out2in_slow_path_node_fn_inline (vm, node, frame);
1383 }
1384
1385 /* *INDENT-OFF* */
1386 VLIB_REGISTER_NODE (nat44_ed_out2in_slowpath_node) = {
1387   .name = "nat44-ed-out2in-slowpath",
1388   .vector_size = sizeof (u32),
1389   .sibling_of = "nat-default",
1390   .format_trace = format_nat44_ed_out2in_trace,
1391   .type = VLIB_NODE_TYPE_INTERNAL,
1392   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1393   .error_strings = nat_out2in_ed_error_strings,
1394   .runtime_data_bytes = sizeof (snat_runtime_t),
1395 };
1396 /* *INDENT-ON* */
1397
1398 static u8 *
1399 format_nat_pre_trace (u8 * s, va_list * args)
1400 {
1401   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1402   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1403   nat_pre_trace_t *t = va_arg (*args, nat_pre_trace_t *);
1404   return format (s, "out2in next_index %d arc_next_index %d", t->next_index,
1405                  t->arc_next_index);
1406 }
1407
1408 VLIB_NODE_FN (nat_pre_out2in_node) (vlib_main_t * vm,
1409                                     vlib_node_runtime_t * node,
1410                                     vlib_frame_t * frame)
1411 {
1412   return nat_pre_node_fn_inline (vm, node, frame,
1413                                  NAT_NEXT_OUT2IN_ED_FAST_PATH);
1414 }
1415
1416 /* *INDENT-OFF* */
1417 VLIB_REGISTER_NODE (nat_pre_out2in_node) = {
1418   .name = "nat-pre-out2in",
1419   .vector_size = sizeof (u32),
1420   .sibling_of = "nat-default",
1421   .format_trace = format_nat_pre_trace,
1422   .type = VLIB_NODE_TYPE_INTERNAL,
1423   .n_errors = 0,
1424  };
1425 /* *INDENT-ON* */
1426
1427 /*
1428  * fd.io coding-style-patch-verification: ON
1429  *
1430  * Local Variables:
1431  * eval: (c-set-style "gnu")
1432  * End:
1433  */