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", tag, t->sw_if_index,
  67               t->next_index);
  68   if (~0 != t->session_index)
  69     {
  70       s = format (s, ", session %d, translation result '%U' via %s",
  71                   t->session_index, format_nat_ed_translation_error,
  72                   t->translation_error,
  73                   t->translation_via_i2of ? "i2of" : "o2if");
  74       s = format (s, "\n  i2of %U", format_nat_6t_flow, &t->i2of);
  75       s = format (s, "\n  o2if %U", format_nat_6t_flow, &t->o2if);
  76     }
  77   if (!t->is_slow_path)
  78     {
  79       if (t->lookup_skipped)
  80         {
  81           s = format (s, "\n lookup skipped - cached session index used");
  82         }
  83       else
  84         {
  85           s = format (s, "\n  search key %U", format_ed_session_kvp,
  86                       &t->search_key);
  87         }
  88     }
  89
  90   return s;
  91 }
  92
  93 static int
  94 next_src_nat (snat_main_t *sm, ip4_header_t *ip, u16 src_port, u16 dst_port,
  95               u32 thread_index, u32 rx_fib_index)
  96 {
  97   clib_bihash_kv_16_8_t kv, value;
  98
  99   init_ed_k (&kv, ip->src_address, src_port, ip->dst_address, dst_port,
 100              rx_fib_index, ip->protocol);
 101   if (!clib_bihash_search_16_8 (&sm->flow_hash, &kv, &value))
 102     return 1;
 103
 104   return 0;
 105 }
 106
 107 static void create_bypass_for_fwd (snat_main_t *sm, vlib_buffer_t *b,
 108                                    snat_session_t *s, ip4_header_t *ip,
 109                                    u32 rx_fib_index, u32 thread_index);
 110
 111 static snat_session_t *create_session_for_static_mapping_ed (
 112   snat_main_t *sm, vlib_buffer_t *b, ip4_address_t i2o_addr, u16 i2o_port,
 113   u32 i2o_fib_index, ip4_address_t o2i_addr, u16 o2i_port, u32 o2i_fib_index,
 114   nat_protocol_t nat_proto, vlib_node_runtime_t *node, u32 rx_fib_index,
 115   u32 thread_index, twice_nat_type_t twice_nat, lb_nat_type_t lb_nat, f64 now,
 116   snat_static_mapping_t *mapping);
 117
 118 static inline u32
 119 icmp_out2in_ed_slow_path (snat_main_t *sm, vlib_buffer_t *b, ip4_header_t *ip,
 120                           icmp46_header_t *icmp, u32 sw_if_index,
 121                           u32 rx_fib_index, vlib_node_runtime_t *node,
 122                           u32 next, f64 now, u32 thread_index,
 123                           snat_session_t **s_p)
 124 {
 125   vlib_main_t *vm = vlib_get_main ();
 126
 127   ip_csum_t sum;
 128   u16 checksum;
 129
 130   snat_session_t *s = 0;
 131   u8 is_addr_only, identity_nat;
 132   ip4_address_t sm_addr;
 133   u16 sm_port;
 134   u32 sm_fib_index;
 135   snat_static_mapping_t *m;
 136   u8 lookup_protocol;
 137   ip4_address_t lookup_saddr, lookup_daddr;
 138   u16 lookup_sport, lookup_dport;
 139
 140   sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
 141   rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 142
 143   if (nat_get_icmp_session_lookup_values (b, ip, &lookup_saddr, &lookup_sport,
 144                                           &lookup_daddr, &lookup_dport,
 145                                           &lookup_protocol))
 146     {
 147       b->error = node->errors[NAT_OUT2IN_ED_ERROR_UNSUPPORTED_PROTOCOL];
 148       next = NAT_NEXT_DROP;
 149       goto out;
 150     }
 151
 152   if (snat_static_mapping_match (
 153         vm, sm, ip->dst_address, lookup_sport, rx_fib_index,
 154         ip_proto_to_nat_proto (ip->protocol), &sm_addr, &sm_port,
 155         &sm_fib_index, 1, &is_addr_only, 0, 0, 0, &identity_nat, &m))
 156     {
 157       // static mapping not matched
 158       if (!sm->forwarding_enabled)
 159         {
 160           /* Don't NAT packet aimed at the intfc address */
 161           if (!is_interface_addr (sm, node, sw_if_index,
 162                                   ip->dst_address.as_u32))
 163             {
 164               b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 165               next = NAT_NEXT_DROP;
 166             }
 167         }
 168       else
 169         {
 170           if (next_src_nat (sm, ip, lookup_sport, lookup_dport, thread_index,
 171                             rx_fib_index))
 172             {
 173               next = NAT_NEXT_IN2OUT_ED_FAST_PATH;
 174             }
 175           else
 176             {
 177               create_bypass_for_fwd (sm, b, s, ip, rx_fib_index, thread_index);
 178             }
 179         }
 180       goto out;
 181     }
 182
 183   if (PREDICT_FALSE (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 184                        ICMP4_echo_reply &&
 185                      (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 186                         ICMP4_echo_request ||
 187                       !is_addr_only)))
 188     {
 189       b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 190       next = NAT_NEXT_DROP;
 191       goto out;
 192     }
 193
 194   if (PREDICT_FALSE (identity_nat))
 195     {
 196       goto out;
 197     }
 198
 199   /* Create session initiated by host from external network */
 200   s = create_session_for_static_mapping_ed (
 201     sm, b, sm_addr, sm_port, sm_fib_index, ip->dst_address, lookup_sport,
 202     rx_fib_index, ip_proto_to_nat_proto (lookup_protocol), node, rx_fib_index,
 203     thread_index, 0, 0, vlib_time_now (vm), m);
 204   if (!s)
 205     next = NAT_NEXT_DROP;
 206
 207   if (PREDICT_TRUE (!ip4_is_fragment (ip)))
 208     {
 209       sum = ip_incremental_checksum_buffer (
 210         vm, b, (u8 *) icmp - (u8 *) vlib_buffer_get_current (b),
 211         ntohs (ip->length) - ip4_header_bytes (ip), 0);
 212       checksum = ~ip_csum_fold (sum);
 213       if (checksum != 0 && checksum != 0xffff)
 214         {
 215           next = NAT_NEXT_DROP;
 216           goto out;
 217         }
 218     }
 219
 220   if (PREDICT_TRUE (next != NAT_NEXT_DROP && s))
 221     {
 222       /* Accounting */
 223       nat44_session_update_counters (
 224         s, now, vlib_buffer_length_in_chain (vm, b), thread_index);
 225       /* Per-user LRU list maintenance */
 226       nat44_session_update_lru (sm, s, thread_index);
 227     }
 228 out:
 229   if (NAT_NEXT_DROP == next && s)
 230     {
 231       nat_ed_session_delete (sm, s, thread_index, 1);
 232       s = 0;
 233     }
 234   *s_p = s;
 235   return next;
 236 }
 237
 238 // allocate exact address based on preference
 239 static_always_inline int
 240 nat_alloc_addr_and_port_exact (snat_address_t * a,
 241                                u32 thread_index,
 242                                nat_protocol_t proto,
 243                                ip4_address_t * addr,
 244                                u16 * port,
 245                                u16 port_per_thread, u32 snat_thread_index)
 246 {
 247   snat_main_t *sm = &snat_main;
 248   u32 portnum;
 249
 250   switch (proto)
 251     {
 252 #define _(N, j, n, s) \
 253     case NAT_PROTOCOL_##N: \
 254       if (a->busy_##n##_ports_per_thread[thread_index] < port_per_thread) \
 255         { \
 256           while (1) \
 257             { \
 258               portnum = (port_per_thread * \
 259                 snat_thread_index) + \
 260                 snat_random_port(0, port_per_thread - 1) + 1024; \
 261               if (a->busy_##n##_port_refcounts[portnum]) \
 262                 continue; \
 263               --a->busy_##n##_port_refcounts[portnum]; \
 264               a->busy_##n##_ports_per_thread[thread_index]++; \
 265               a->busy_##n##_ports++; \
 266               *addr = a->addr; \
 267               *port = clib_host_to_net_u16(portnum); \
 268               return 0; \
 269             } \
 270         } \
 271       break;
 272       foreach_nat_protocol
 273 #undef _
 274         default : nat_elog_info (sm, "unknown protocol");
 275       return 1;
 276     }
 277
 278   /* Totally out of translations to use... */
 279   nat_ipfix_logging_addresses_exhausted (thread_index, 0);
 280   return 1;
 281 }
 282
 283 static_always_inline int
 284 nat44_ed_alloc_outside_addr_and_port (snat_address_t *addresses, u32 fib_index,
 285                                       u32 thread_index, nat_protocol_t proto,
 286                                       ip4_address_t *addr, u16 *port,
 287                                       u16 port_per_thread,
 288                                       u32 snat_thread_index)
 289 {
 290   snat_main_t *sm = &snat_main;
 291   snat_address_t *a, *ga = 0;
 292   u32 portnum;
 293   int i;
 294
 295   for (i = 0; i < vec_len (addresses); i++)
 296     {
 297       a = addresses + i;
 298       switch (proto)
 299         {
 300 #define _(N, j, n, s)                                                         \
 301   case NAT_PROTOCOL_##N:                                                      \
 302     if (a->busy_##n##_ports_per_thread[thread_index] < port_per_thread)       \
 303       {                                                                       \
 304         if (a->fib_index == fib_index)                                        \
 305           {                                                                   \
 306             while (1)                                                         \
 307               {                                                               \
 308                 portnum = (port_per_thread * snat_thread_index) +             \
 309                           snat_random_port (0, port_per_thread - 1) + 1024;   \
 310                 if (a->busy_##n##_port_refcounts[portnum])                    \
 311                   continue;                                                   \
 312                 --a->busy_##n##_port_refcounts[portnum];                      \
 313                 a->busy_##n##_ports_per_thread[thread_index]++;               \
 314                 a->busy_##n##_ports++;                                        \
 315                 *addr = a->addr;                                              \
 316                 *port = clib_host_to_net_u16 (portnum);                       \
 317                 return 0;                                                     \
 318               }                                                               \
 319           }                                                                   \
 320         else if (a->fib_index == ~0)                                          \
 321           {                                                                   \
 322             ga = a;                                                           \
 323           }                                                                   \
 324       }                                                                       \
 325     break;
 326           foreach_nat_protocol
 327 #undef _
 328             default : nat_elog_info (sm, "unknown protocol");
 329           return 1;
 330         }
 331     }
 332
 333   if (ga)
 334     {
 335       a = ga;
 336       switch (proto)
 337         {
 338 #define _(N, j, n, s)                                                         \
 339   case NAT_PROTOCOL_##N:                                                      \
 340     while (1)                                                                 \
 341       {                                                                       \
 342         portnum = (port_per_thread * snat_thread_index) +                     \
 343                   snat_random_port (0, port_per_thread - 1) + 1024;           \
 344         if (a->busy_##n##_port_refcounts[portnum])                            \
 345           continue;                                                           \
 346         ++a->busy_##n##_port_refcounts[portnum];                              \
 347         a->busy_##n##_ports_per_thread[thread_index]++;                       \
 348         a->busy_##n##_ports++;                                                \
 349         *addr = a->addr;                                                      \
 350         *port = clib_host_to_net_u16 (portnum);                               \
 351         return 0;                                                             \
 352       }
 353           break;
 354           foreach_nat_protocol
 355 #undef _
 356             default : nat_elog_info (sm, "unknown protocol");
 357           return 1;
 358         }
 359     }
 360
 361   /* Totally out of translations to use... */
 362   nat_ipfix_logging_addresses_exhausted (thread_index, 0);
 363   return 1;
 364 }
 365
 366 static snat_session_t *
 367 create_session_for_static_mapping_ed (
 368   snat_main_t *sm, vlib_buffer_t *b, ip4_address_t i2o_addr, u16 i2o_port,
 369   u32 i2o_fib_index, ip4_address_t o2i_addr, u16 o2i_port, u32 o2i_fib_index,
 370   nat_protocol_t nat_proto, vlib_node_runtime_t *node, u32 rx_fib_index,
 371   u32 thread_index, twice_nat_type_t twice_nat, lb_nat_type_t lb_nat, f64 now,
 372   snat_static_mapping_t *mapping)
 373 {
 374   snat_session_t *s;
 375   ip4_header_t *ip;
 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
 396   s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 397   s->ext_host_port =
 398     nat_proto == NAT_PROTOCOL_ICMP ? 0 : vnet_buffer (b)->ip.reass.l4_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   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 578   vlib_main_t *vm = vlib_get_main ();
 579   f64 now = vlib_time_now (vm);
 580   u16 lookup_sport, lookup_dport;
 581   u8 lookup_protocol;
 582   ip4_address_t lookup_saddr, lookup_daddr;
 583
 584   if (ip->protocol == IP_PROTOCOL_ICMP)
 585     {
 586       if (nat_get_icmp_session_lookup_values (b, ip, &lookup_saddr,
 587                                               &lookup_sport, &lookup_daddr,
 588                                               &lookup_dport, &lookup_protocol))
 589         return;
 590     }
 591   else
 592     {
 593       if (ip->protocol == IP_PROTOCOL_UDP || ip->protocol == IP_PROTOCOL_TCP)
 594         {
 595           lookup_sport = vnet_buffer (b)->ip.reass.l4_dst_port;
 596           lookup_dport = vnet_buffer (b)->ip.reass.l4_src_port;
 597         }
 598       else
 599         {
 600           lookup_sport = 0;
 601           lookup_dport = 0;
 602         }
 603       lookup_saddr.as_u32 = ip->dst_address.as_u32;
 604       lookup_daddr.as_u32 = ip->src_address.as_u32;
 605       lookup_protocol = ip->protocol;
 606     }
 607
 608   init_ed_k (&kv, lookup_saddr, lookup_sport, lookup_daddr, lookup_dport,
 609              rx_fib_index, lookup_protocol);
 610
 611   if (!clib_bihash_search_16_8 (&sm->flow_hash, &kv, &value))
 612     {
 613       ASSERT (thread_index == ed_value_get_thread_index (&value));
 614       s =
 615         pool_elt_at_index (tsm->sessions,
 616                            ed_value_get_session_index (&value));
 617     }
 618   else if (ip->protocol == IP_PROTOCOL_ICMP &&
 619            icmp_type_is_error_message
 620            (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags))
 621     {
 622       return;
 623     }
 624   else
 625     {
 626       u32 proto;
 627
 628       if (PREDICT_FALSE
 629           (nat44_ed_maximum_sessions_exceeded
 630            (sm, rx_fib_index, thread_index)))
 631         return;
 632
 633       s = nat_ed_session_alloc (sm, thread_index, now, ip->protocol);
 634       if (!s)
 635         {
 636           nat_elog_warn (sm, "create NAT session failed");
 637           return;
 638         }
 639
 640       proto = ip_proto_to_nat_proto (ip->protocol);
 641
 642       s->ext_host_addr = ip->src_address;
 643       s->ext_host_port = lookup_dport;
 644       s->flags |= SNAT_SESSION_FLAG_FWD_BYPASS;
 645       s->out2in.addr = ip->dst_address;
 646       s->out2in.port = lookup_sport;
 647       s->nat_proto = proto;
 648       if (proto == NAT_PROTOCOL_OTHER)
 649         {
 650           s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 651           s->out2in.port = ip->protocol;
 652         }
 653       s->out2in.fib_index = rx_fib_index;
 654       s->in2out.addr = s->out2in.addr;
 655       s->in2out.port = s->out2in.port;
 656       s->in2out.fib_index = s->out2in.fib_index;
 657
 658       nat_6t_i2o_flow_init (sm, thread_index, s, ip->dst_address, lookup_sport,
 659                             ip->src_address, lookup_dport, rx_fib_index,
 660                             ip->protocol);
 661       nat_6t_flow_txfib_rewrite_set (&s->i2o, rx_fib_index);
 662       if (nat_ed_ses_i2o_flow_hash_add_del (sm, thread_index, s, 1))
 663         {
 664           nat_elog_notice (sm, "in2out flow add failed");
 665           nat_ed_session_delete (sm, s, thread_index, 1);
 666           return;
 667         }
 668
 669       per_vrf_sessions_register_session (s, thread_index);
 670     }
 671
 672   if (ip->protocol == IP_PROTOCOL_TCP)
 673     {
 674       tcp_header_t *tcp = ip4_next_header (ip);
 675       nat44_set_tcp_session_state_o2i (sm, now, s, tcp->flags,
 676                                        tcp->ack_number, tcp->seq_number,
 677                                        thread_index);
 678     }
 679
 680   /* Accounting */
 681   nat44_session_update_counters (s, now, 0, thread_index);
 682   /* Per-user LRU list maintenance */
 683   nat44_session_update_lru (sm, s, thread_index);
 684 }
 685
 686 static snat_session_t *
 687 nat44_ed_out2in_slowpath_unknown_proto (snat_main_t *sm, vlib_buffer_t *b,
 688                                         ip4_header_t *ip, u32 rx_fib_index,
 689                                         u32 thread_index, f64 now,
 690                                         vlib_main_t *vm,
 691                                         vlib_node_runtime_t *node)
 692 {
 693   clib_bihash_kv_8_8_t kv, value;
 694   snat_static_mapping_t *m;
 695   snat_session_t *s;
 696
 697   if (PREDICT_FALSE (
 698         nat44_ed_maximum_sessions_exceeded (sm, rx_fib_index, thread_index)))
 699     {
 700       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 701       nat_elog_notice (sm, "maximum sessions exceeded");
 702       return 0;
 703     }
 704
 705   init_nat_k (&kv, ip->dst_address, 0, 0, 0);
 706   if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
 707     {
 708       b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 709       return 0;
 710     }
 711
 712   m = pool_elt_at_index (sm->static_mappings, value.value);
 713
 714   /* Create a new session */
 715   s = nat_ed_session_alloc (sm, thread_index, now, ip->protocol);
 716   if (!s)
 717     {
 718       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 719       nat_elog_warn (sm, "create NAT session failed");
 720       return 0;
 721     }
 722
 723   s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 724   s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 725   s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 726   s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 727   s->out2in.addr.as_u32 = ip->dst_address.as_u32;
 728   s->out2in.fib_index = rx_fib_index;
 729   s->in2out.addr.as_u32 = m->local_addr.as_u32;
 730   s->in2out.fib_index = m->fib_index;
 731   s->in2out.port = s->out2in.port = ip->protocol;
 732
 733   nat_6t_o2i_flow_init (sm, thread_index, s, ip->dst_address, 0,
 734                         ip->src_address, 0, m->fib_index, ip->protocol);
 735   nat_6t_flow_saddr_rewrite_set (&s->i2o, ip->dst_address.as_u32);
 736   if (nat_ed_ses_i2o_flow_hash_add_del (sm, thread_index, s, 1))
 737     {
 738       nat_elog_notice (sm, "in2out key add failed");
 739       nat_ed_session_delete (sm, s, thread_index, 1);
 740       return NULL;
 741     }
 742
 743   nat_6t_o2i_flow_init (sm, thread_index, s, ip->src_address, 0,
 744                         ip->dst_address, 0, rx_fib_index, ip->protocol);
 745   nat_6t_flow_daddr_rewrite_set (&s->o2i, m->local_addr.as_u32);
 746   nat_6t_flow_txfib_rewrite_set (&s->o2i, m->fib_index);
 747   if (nat_ed_ses_o2i_flow_hash_add_del (sm, thread_index, s, 1))
 748     {
 749       nat_elog_notice (sm, "out2in flow hash add failed");
 750       nat_ed_session_delete (sm, s, thread_index, 1);
 751       return NULL;
 752     }
 753
 754   per_vrf_sessions_register_session (s, thread_index);
 755
 756   /* Accounting */
 757   nat44_session_update_counters (s, now, vlib_buffer_length_in_chain (vm, b),
 758                                  thread_index);
 759   /* Per-user LRU list maintenance */
 760   nat44_session_update_lru (sm, s, thread_index);
 761
 762   return s;
 763 }
 764
 765 static inline uword
 766 nat44_ed_out2in_fast_path_node_fn_inline (vlib_main_t * vm,
 767                                           vlib_node_runtime_t * node,
 768                                           vlib_frame_t * frame,
 769                                           int is_multi_worker)
 770 {
 771   u32 n_left_from, *from;
 772   snat_main_t *sm = &snat_main;
 773   f64 now = vlib_time_now (vm);
 774   u32 thread_index = vm->thread_index;
 775   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 776
 777   from = vlib_frame_vector_args (frame);
 778   n_left_from = frame->n_vectors;
 779
 780   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b = bufs;
 781   u16 nexts[VLIB_FRAME_SIZE], *next = nexts;
 782   vlib_get_buffers (vm, from, b, n_left_from);
 783
 784   while (n_left_from > 0)
 785     {
 786       vlib_buffer_t *b0;
 787       u32 sw_if_index0, rx_fib_index0;
 788       nat_protocol_t proto0;
 789       ip4_header_t *ip0;
 790       snat_session_t *s0 = 0;
 791       clib_bihash_kv_16_8_t kv0, value0;
 792       nat_translation_error_e translation_error = NAT_ED_TRNSL_ERR_SUCCESS;
 793       nat_6t_flow_t *f = 0;
 794       nat_6t_t lookup;
 795       int lookup_skipped = 0;
 796
 797       b0 = *b;
 798       b++;
 799
 800       /* Prefetch next iteration. */
 801       if (PREDICT_TRUE (n_left_from >= 2))
 802         {
 803           vlib_buffer_t *p2;
 804
 805           p2 = *b;
 806
 807           vlib_prefetch_buffer_header (p2, LOAD);
 808
 809           CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, LOAD);
 810         }
 811
 812       next[0] = vnet_buffer2 (b0)->nat.arc_next;
 813
 814       lookup.sport = vnet_buffer (b0)->ip.reass.l4_src_port;
 815       lookup.dport = vnet_buffer (b0)->ip.reass.l4_dst_port;
 816
 817       vnet_buffer (b0)->snat.flags = 0;
 818       ip0 = vlib_buffer_get_current (b0);
 819
 820       sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 821       rx_fib_index0 =
 822         fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4, sw_if_index0);
 823
 824       lookup.fib_index = rx_fib_index0;
 825
 826       if (PREDICT_FALSE (ip0->ttl == 1))
 827         {
 828           vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 829           icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 830                                        ICMP4_time_exceeded_ttl_exceeded_in_transit,
 831                                        0);
 832           next[0] = NAT_NEXT_ICMP_ERROR;
 833           goto trace0;
 834         }
 835
 836       proto0 = ip_proto_to_nat_proto (ip0->protocol);
 837
 838       if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
 839         {
 840           if (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
 841                 ICMP4_echo_request &&
 842               vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
 843                 ICMP4_echo_reply &&
 844               !icmp_type_is_error_message (
 845                 vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags))
 846             {
 847               b0->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 848               next[0] = NAT_NEXT_DROP;
 849               goto trace0;
 850             }
 851           int err = nat_get_icmp_session_lookup_values (
 852             b0, ip0, &lookup.saddr, &lookup.sport, &lookup.daddr,
 853             &lookup.dport, &lookup.proto);
 854           if (err != 0)
 855             {
 856               b0->error = node->errors[err];
 857               next[0] = NAT_NEXT_DROP;
 858               goto trace0;
 859             }
 860         }
 861       else
 862         {
 863           lookup.saddr.as_u32 = ip0->src_address.as_u32;
 864           lookup.daddr.as_u32 = ip0->dst_address.as_u32;
 865           lookup.proto = ip0->protocol;
 866         }
 867
 868       /* there might be a stashed index in vnet_buffer2 from handoff or
 869        * classify node, see if it can be used */
 870       if (is_multi_worker &&
 871           !pool_is_free_index (tsm->sessions,
 872                                vnet_buffer2 (b0)->nat.cached_session_index))
 873         {
 874           s0 = pool_elt_at_index (tsm->sessions,
 875                                   vnet_buffer2 (b0)->nat.cached_session_index);
 876           if (PREDICT_TRUE (nat_6t_t_eq (&s0->o2i.match, &lookup)) ||
 877               (s0->flags & SNAT_SESSION_FLAG_TWICE_NAT &&
 878                nat_6t_t_eq (&s0->i2o.match, &lookup)))
 879             {
 880               /* yes, this is the droid we're looking for */
 881               lookup_skipped = 1;
 882               goto skip_lookup;
 883             }
 884           s0 = NULL;
 885         }
 886
 887       init_ed_k (&kv0, lookup.saddr, lookup.sport, lookup.daddr, lookup.dport,
 888                  lookup.fib_index, lookup.proto);
 889
 890       // lookup flow
 891       if (clib_bihash_search_16_8 (&sm->flow_hash, &kv0, &value0))
 892         {
 893           // flow does not exist go slow path
 894           next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 895           goto trace0;
 896         }
 897       ASSERT (thread_index == ed_value_get_thread_index (&value0));
 898       s0 =
 899         pool_elt_at_index (tsm->sessions,
 900                            ed_value_get_session_index (&value0));
 901     skip_lookup:
 902
 903       if (PREDICT_FALSE (per_vrf_sessions_is_expired (s0, thread_index)))
 904         {
 905           // session is closed, go slow path
 906           nat_free_session_data (sm, s0, thread_index, 0);
 907           nat_ed_session_delete (sm, s0, thread_index, 1);
 908           next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 909           goto trace0;
 910         }
 911
 912       if (s0->tcp_closed_timestamp)
 913         {
 914           if (now >= s0->tcp_closed_timestamp)
 915             {
 916               // session is closed, go slow path, freed in slow path
 917               next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 918             }
 919           else
 920             {
 921               // session in transitory timeout, drop
 922               b0->error = node->errors[NAT_OUT2IN_ED_ERROR_TCP_CLOSED];
 923               next[0] = NAT_NEXT_DROP;
 924             }
 925           goto trace0;
 926         }
 927
 928       // drop if session expired
 929       u64 sess_timeout_time;
 930       sess_timeout_time =
 931         s0->last_heard + (f64) nat44_session_get_timeout (sm, s0);
 932       if (now >= sess_timeout_time)
 933         {
 934           // session is closed, go slow path
 935           nat_free_session_data (sm, s0, thread_index, 0);
 936           nat_ed_session_delete (sm, s0, thread_index, 1);
 937           next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 938           goto trace0;
 939         }
 940
 941       if (nat_6t_t_eq (&s0->o2i.match, &lookup))
 942         {
 943           f = &s0->o2i;
 944         }
 945       else if (s0->flags & SNAT_SESSION_FLAG_TWICE_NAT &&
 946                nat_6t_t_eq (&s0->i2o.match, &lookup))
 947         {
 948           f = &s0->i2o;
 949         }
 950       else
 951         {
 952           /*
 953            * Send DHCP packets to the ipv4 stack, or we won't
 954            * be able to use dhcp client on the outside interface
 955            */
 956           if (PREDICT_FALSE (
 957                 proto0 == NAT_PROTOCOL_UDP &&
 958                 (vnet_buffer (b0)->ip.reass.l4_dst_port ==
 959                  clib_host_to_net_u16 (UDP_DST_PORT_dhcp_to_client))))
 960             {
 961               goto trace0;
 962             }
 963
 964           if (!sm->forwarding_enabled)
 965             {
 966               b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 967               next[0] = NAT_NEXT_DROP;
 968               goto trace0;
 969             }
 970           else
 971             {
 972               if (nat_6t_t_eq (&s0->i2o.match, &lookup))
 973                 {
 974                   f = &s0->i2o;
 975                 }
 976               else
 977                 {
 978                   // FIXME TODO bypass ???
 979                   //  create_bypass_for_fwd (sm, b0, s0, ip0, rx_fib_index0,
 980                   //                       thread_index);
 981                   translation_error = NAT_ED_TRNSL_ERR_FLOW_MISMATCH;
 982                   nat_free_session_data (sm, s0, thread_index, 0);
 983                   nat_ed_session_delete (sm, s0, thread_index, 1);
 984                   next[0] = NAT_NEXT_DROP;
 985                   goto trace0;
 986                 }
 987             }
 988         }
 989
 990       if (NAT_ED_TRNSL_ERR_SUCCESS !=
 991           (translation_error = nat_6t_flow_buf_translate (
 992              sm, b0, ip0, f, proto0, 0 /* is_output_feature */)))
 993         {
 994           next[0] = NAT_NEXT_DROP;
 995           goto trace0;
 996         }
 997
 998       switch (proto0)
 999         {
1000         case NAT_PROTOCOL_TCP:
1001           vlib_increment_simple_counter (&sm->counters.fastpath.out2in.tcp,
1002                                          thread_index, sw_if_index0, 1);
1003           nat44_set_tcp_session_state_o2i (sm, now, s0,
1004                                            vnet_buffer (b0)->ip.
1005                                            reass.icmp_type_or_tcp_flags,
1006                                            vnet_buffer (b0)->ip.
1007                                            reass.tcp_ack_number,
1008                                            vnet_buffer (b0)->ip.
1009                                            reass.tcp_seq_number,
1010                                            thread_index);
1011           break;
1012         case NAT_PROTOCOL_UDP:
1013           vlib_increment_simple_counter (&sm->counters.fastpath.out2in.udp,
1014                                          thread_index, sw_if_index0, 1);
1015           break;
1016         case NAT_PROTOCOL_ICMP:
1017           vlib_increment_simple_counter (&sm->counters.fastpath.out2in.icmp,
1018                                          thread_index, sw_if_index0, 1);
1019           break;
1020         case NAT_PROTOCOL_OTHER:
1021           vlib_increment_simple_counter (&sm->counters.fastpath.out2in.other,
1022                                          thread_index, sw_if_index0, 1);
1023           break;
1024         }
1025
1026       /* Accounting */
1027       nat44_session_update_counters (s0, now,
1028                                      vlib_buffer_length_in_chain (vm, b0),
1029                                      thread_index);
1030       /* Per-user LRU list maintenance */
1031       nat44_session_update_lru (sm, s0, thread_index);
1032
1033     trace0:
1034       if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1035                          && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1036         {
1037           nat44_ed_out2in_trace_t *t =
1038             vlib_add_trace (vm, node, b0, sizeof (*t));
1039           t->sw_if_index = sw_if_index0;
1040           t->next_index = next[0];
1041           t->is_slow_path = 0;
1042           t->translation_error = translation_error;
1043           clib_memcpy (&t->search_key, &kv0, sizeof (t->search_key));
1044           t->lookup_skipped = lookup_skipped;
1045
1046           if (s0)
1047             {
1048               t->session_index = s0 - tsm->sessions;
1049               clib_memcpy (&t->i2of, &s0->i2o, sizeof (t->i2of));
1050               clib_memcpy (&t->o2if, &s0->o2i, sizeof (t->o2if));
1051               t->translation_via_i2of = (&s0->i2o == f);
1052             }
1053           else
1054             {
1055               t->session_index = ~0;
1056             }
1057         }
1058
1059       if (next[0] == NAT_NEXT_DROP)
1060         {
1061           vlib_increment_simple_counter (&sm->counters.fastpath.out2in.drops,
1062                                          thread_index, sw_if_index0, 1);
1063         }
1064
1065       n_left_from--;
1066       next++;
1067     }
1068
1069   vlib_buffer_enqueue_to_next (vm, node, from, (u16 *) nexts,
1070                                frame->n_vectors);
1071   return frame->n_vectors;
1072 }
1073
1074 static inline uword
1075 nat44_ed_out2in_slow_path_node_fn_inline (vlib_main_t * vm,
1076                                           vlib_node_runtime_t * node,
1077                                           vlib_frame_t * frame)
1078 {
1079   u32 n_left_from, *from;
1080   snat_main_t *sm = &snat_main;
1081   f64 now = vlib_time_now (vm);
1082   u32 thread_index = vm->thread_index;
1083   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
1084   snat_static_mapping_t *m;
1085
1086   from = vlib_frame_vector_args (frame);
1087   n_left_from = frame->n_vectors;
1088
1089   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b = bufs;
1090   u16 nexts[VLIB_FRAME_SIZE], *next = nexts;
1091   vlib_get_buffers (vm, from, b, n_left_from);
1092
1093   while (n_left_from > 0)
1094     {
1095       vlib_buffer_t *b0;
1096       u32 sw_if_index0, rx_fib_index0;
1097       nat_protocol_t proto0;
1098       ip4_header_t *ip0;
1099       udp_header_t *udp0;
1100       icmp46_header_t *icmp0;
1101       snat_session_t *s0 = 0;
1102       clib_bihash_kv_16_8_t kv0, value0;
1103       lb_nat_type_t lb_nat0;
1104       twice_nat_type_t twice_nat0;
1105       u8 identity_nat0;
1106       ip4_address_t sm_addr;
1107       u16 sm_port;
1108       u32 sm_fib_index;
1109       nat_translation_error_e translation_error = NAT_ED_TRNSL_ERR_SUCCESS;
1110
1111       b0 = *b;
1112       next[0] = vnet_buffer2 (b0)->nat.arc_next;
1113
1114       vnet_buffer (b0)->snat.flags = 0;
1115       ip0 = vlib_buffer_get_current (b0);
1116
1117       sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1118       rx_fib_index0 =
1119         fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4, sw_if_index0);
1120
1121       if (PREDICT_FALSE (ip0->ttl == 1))
1122         {
1123           vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1124           icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1125                                        ICMP4_time_exceeded_ttl_exceeded_in_transit,
1126                                        0);
1127           next[0] = NAT_NEXT_ICMP_ERROR;
1128           goto trace0;
1129         }
1130
1131       udp0 = ip4_next_header (ip0);
1132       icmp0 = (icmp46_header_t *) udp0;
1133       proto0 = ip_proto_to_nat_proto (ip0->protocol);
1134
1135       if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
1136         {
1137           s0 = nat44_ed_out2in_slowpath_unknown_proto (
1138             sm, b0, ip0, rx_fib_index0, thread_index, now, vm, node);
1139           if (!sm->forwarding_enabled)
1140             {
1141               if (!s0)
1142                 next[0] = NAT_NEXT_DROP;
1143             }
1144           if (NAT_NEXT_DROP != next[0] &&
1145               NAT_ED_TRNSL_ERR_SUCCESS !=
1146                 (translation_error = nat_6t_flow_buf_translate (
1147                    sm, b0, ip0, &s0->o2i, proto0, 0 /* is_output_feature */)))
1148             {
1149               goto trace0;
1150             }
1151
1152           vlib_increment_simple_counter (&sm->counters.slowpath.out2in.other,
1153                                          thread_index, sw_if_index0, 1);
1154           goto trace0;
1155         }
1156
1157       if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
1158         {
1159           next[0] = icmp_out2in_ed_slow_path
1160             (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1161              next[0], now, thread_index, &s0);
1162
1163           if (NAT_NEXT_DROP != next[0] && s0 &&
1164               NAT_ED_TRNSL_ERR_SUCCESS !=
1165                 (translation_error = nat_6t_flow_buf_translate (
1166                    sm, b0, ip0, &s0->o2i, proto0, 0 /* is_output_feature */)))
1167             {
1168               goto trace0;
1169             }
1170
1171           vlib_increment_simple_counter (&sm->counters.slowpath.out2in.icmp,
1172                                          thread_index, sw_if_index0, 1);
1173           goto trace0;
1174         }
1175
1176       init_ed_k (&kv0, ip0->src_address,
1177                  vnet_buffer (b0)->ip.reass.l4_src_port, ip0->dst_address,
1178                  vnet_buffer (b0)->ip.reass.l4_dst_port, rx_fib_index0,
1179                  ip0->protocol);
1180
1181       s0 = NULL;
1182       if (!clib_bihash_search_16_8 (&sm->flow_hash, &kv0, &value0))
1183         {
1184           ASSERT (thread_index == ed_value_get_thread_index (&value0));
1185           s0 =
1186             pool_elt_at_index (tsm->sessions,
1187                                ed_value_get_session_index (&value0));
1188
1189           if (s0->tcp_closed_timestamp && now >= s0->tcp_closed_timestamp)
1190             {
1191               nat_free_session_data (sm, s0, thread_index, 0);
1192               nat_ed_session_delete (sm, s0, thread_index, 1);
1193               s0 = NULL;
1194             }
1195         }
1196
1197       if (!s0)
1198         {
1199           /* Try to match static mapping by external address and port,
1200              destination address and port in packet */
1201
1202           if (snat_static_mapping_match (
1203                 vm, sm, ip0->dst_address,
1204                 vnet_buffer (b0)->ip.reass.l4_dst_port, rx_fib_index0, proto0,
1205                 &sm_addr, &sm_port, &sm_fib_index, 1, 0, &twice_nat0, &lb_nat0,
1206                 &ip0->src_address, &identity_nat0, &m))
1207             {
1208               /*
1209                * Send DHCP packets to the ipv4 stack, or we won't
1210                * be able to use dhcp client on the outside interface
1211                */
1212               if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_UDP
1213                                  && (vnet_buffer (b0)->ip.reass.l4_dst_port ==
1214                                      clib_host_to_net_u16
1215                                      (UDP_DST_PORT_dhcp_to_client))))
1216                 {
1217                   goto trace0;
1218                 }
1219
1220               if (!sm->forwarding_enabled)
1221                 {
1222                   b0->error =
1223                     node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
1224                   next[0] = NAT_NEXT_DROP;
1225                 }
1226               else
1227                 {
1228                   if (next_src_nat
1229                       (sm, ip0, vnet_buffer (b0)->ip.reass.l4_src_port,
1230                        vnet_buffer (b0)->ip.reass.l4_dst_port,
1231                        thread_index, rx_fib_index0))
1232                     {
1233                       next[0] = NAT_NEXT_IN2OUT_ED_FAST_PATH;
1234                     }
1235                   else
1236                     {
1237                       create_bypass_for_fwd (sm, b0, s0, ip0, rx_fib_index0,
1238                                              thread_index);
1239                     }
1240                 }
1241               goto trace0;
1242             }
1243
1244           if (PREDICT_FALSE (identity_nat0))
1245             goto trace0;
1246
1247           if ((proto0 == NAT_PROTOCOL_TCP)
1248               && !tcp_flags_is_init (vnet_buffer (b0)->ip.
1249                                      reass.icmp_type_or_tcp_flags))
1250             {
1251               b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
1252               next[0] = NAT_NEXT_DROP;
1253               goto trace0;
1254             }
1255
1256           /* Create session initiated by host from external network */
1257           s0 = create_session_for_static_mapping_ed (sm, b0,
1258                                                      sm_addr, sm_port,
1259                                                      sm_fib_index,
1260                                                      ip0->dst_address,
1261                                                      vnet_buffer (b0)->
1262                                                      ip.reass.l4_dst_port,
1263                                                      rx_fib_index0, proto0,
1264                                                      node, rx_fib_index0,
1265                                                      thread_index, twice_nat0,
1266                                                      lb_nat0, now, m);
1267           if (!s0)
1268             {
1269               next[0] = NAT_NEXT_DROP;
1270               goto trace0;
1271             }
1272         }
1273
1274       if (NAT_ED_TRNSL_ERR_SUCCESS !=
1275           (translation_error = nat_6t_flow_buf_translate (
1276              sm, b0, ip0, &s0->o2i, proto0, 0 /* is_output_feature */)))
1277         {
1278           next[0] = NAT_NEXT_DROP;
1279           goto trace0;
1280         }
1281
1282       if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
1283         {
1284           vlib_increment_simple_counter (&sm->counters.slowpath.out2in.tcp,
1285                                          thread_index, sw_if_index0, 1);
1286           nat44_set_tcp_session_state_o2i (sm, now, s0,
1287                                            vnet_buffer (b0)->ip.
1288                                            reass.icmp_type_or_tcp_flags,
1289                                            vnet_buffer (b0)->ip.
1290                                            reass.tcp_ack_number,
1291                                            vnet_buffer (b0)->ip.
1292                                            reass.tcp_seq_number,
1293                                            thread_index);
1294         }
1295       else
1296         {
1297           vlib_increment_simple_counter (&sm->counters.slowpath.out2in.udp,
1298                                          thread_index, sw_if_index0, 1);
1299         }
1300
1301       /* Accounting */
1302       nat44_session_update_counters (s0, now,
1303                                      vlib_buffer_length_in_chain (vm, b0),
1304                                      thread_index);
1305       /* Per-user LRU list maintenance */
1306       nat44_session_update_lru (sm, s0, thread_index);
1307
1308     trace0:
1309       if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1310                          && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1311         {
1312           nat44_ed_out2in_trace_t *t =
1313             vlib_add_trace (vm, node, b0, sizeof (*t));
1314           t->sw_if_index = sw_if_index0;
1315           t->next_index = next[0];
1316           t->is_slow_path = 1;
1317           t->translation_error = translation_error;
1318           clib_memcpy (&t->search_key, &kv0, sizeof (t->search_key));
1319
1320           if (s0)
1321             {
1322               t->session_index = s0 - tsm->sessions;
1323               clib_memcpy (&t->i2of, &s0->i2o, sizeof (t->i2of));
1324               clib_memcpy (&t->o2if, &s0->o2i, sizeof (t->o2if));
1325             }
1326           else
1327             {
1328               t->session_index = ~0;
1329             }
1330         }
1331
1332       if (next[0] == NAT_NEXT_DROP)
1333         {
1334           vlib_increment_simple_counter (&sm->counters.slowpath.out2in.drops,
1335                                          thread_index, sw_if_index0, 1);
1336         }
1337
1338       n_left_from--;
1339       next++;
1340       b++;
1341     }
1342
1343   vlib_buffer_enqueue_to_next (vm, node, from, (u16 *) nexts,
1344                                frame->n_vectors);
1345
1346   return frame->n_vectors;
1347 }
1348
1349 VLIB_NODE_FN (nat44_ed_out2in_node) (vlib_main_t * vm,
1350                                      vlib_node_runtime_t * node,
1351                                      vlib_frame_t * frame)
1352 {
1353   if (snat_main.num_workers > 1)
1354     {
1355       return nat44_ed_out2in_fast_path_node_fn_inline (vm, node, frame, 1);
1356     }
1357   else
1358     {
1359       return nat44_ed_out2in_fast_path_node_fn_inline (vm, node, frame, 0);
1360     }
1361 }
1362
1363 /* *INDENT-OFF* */
1364 VLIB_REGISTER_NODE (nat44_ed_out2in_node) = {
1365   .name = "nat44-ed-out2in",
1366   .vector_size = sizeof (u32),
1367   .sibling_of = "nat-default",
1368   .format_trace = format_nat44_ed_out2in_trace,
1369   .type = VLIB_NODE_TYPE_INTERNAL,
1370   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1371   .error_strings = nat_out2in_ed_error_strings,
1372   .runtime_data_bytes = sizeof (snat_runtime_t),
1373 };
1374 /* *INDENT-ON* */
1375
1376 VLIB_NODE_FN (nat44_ed_out2in_slowpath_node) (vlib_main_t * vm,
1377                                               vlib_node_runtime_t * node,
1378                                               vlib_frame_t * frame)
1379 {
1380   return nat44_ed_out2in_slow_path_node_fn_inline (vm, node, frame);
1381 }
1382
1383 /* *INDENT-OFF* */
1384 VLIB_REGISTER_NODE (nat44_ed_out2in_slowpath_node) = {
1385   .name = "nat44-ed-out2in-slowpath",
1386   .vector_size = sizeof (u32),
1387   .sibling_of = "nat-default",
1388   .format_trace = format_nat44_ed_out2in_trace,
1389   .type = VLIB_NODE_TYPE_INTERNAL,
1390   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1391   .error_strings = nat_out2in_ed_error_strings,
1392   .runtime_data_bytes = sizeof (snat_runtime_t),
1393 };
1394 /* *INDENT-ON* */
1395
1396 static u8 *
1397 format_nat_pre_trace (u8 * s, va_list * args)
1398 {
1399   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1400   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1401   nat_pre_trace_t *t = va_arg (*args, nat_pre_trace_t *);
1402   return format (s, "out2in next_index %d arc_next_index %d", t->next_index,
1403                  t->arc_next_index);
1404 }
1405
1406 VLIB_NODE_FN (nat_pre_out2in_node) (vlib_main_t * vm,
1407                                     vlib_node_runtime_t * node,
1408                                     vlib_frame_t * frame)
1409 {
1410   return nat_pre_node_fn_inline (vm, node, frame,
1411                                  NAT_NEXT_OUT2IN_ED_FAST_PATH);
1412 }
1413
1414 /* *INDENT-OFF* */
1415 VLIB_REGISTER_NODE (nat_pre_out2in_node) = {
1416   .name = "nat-pre-out2in",
1417   .vector_size = sizeof (u32),
1418   .sibling_of = "nat-default",
1419   .format_trace = format_nat_pre_trace,
1420   .type = VLIB_NODE_TYPE_INTERNAL,
1421   .n_errors = 0,
1422  };
1423 /* *INDENT-ON* */
1424
1425 /*
1426  * fd.io coding-style-patch-verification: ON
1427  *
1428  * Local Variables:
1429  * eval: (c-set-style "gnu")
1430  * End:
1431  */