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         vm, 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   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 376
 377   if (PREDICT_FALSE
 378       (nat44_ed_maximum_sessions_exceeded (sm, rx_fib_index, thread_index)))
 379     {
 380       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 381       nat_elog_notice (sm, "maximum sessions exceeded");
 382       return 0;
 383     }
 384
 385   s = nat_ed_session_alloc (sm, thread_index, now, nat_proto);
 386   if (!s)
 387     {
 388       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 389       nat_elog_warn (sm, "create NAT session failed");
 390       return 0;
 391     }
 392
 393   ip = vlib_buffer_get_current (b);
 394
 395   s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 396   s->ext_host_port =
 397     nat_proto == NAT_PROTOCOL_ICMP ? 0 : vnet_buffer (b)->ip.reass.l4_src_port;
 398   s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 399   if (lb_nat)
 400     s->flags |= SNAT_SESSION_FLAG_LOAD_BALANCING;
 401   if (lb_nat == AFFINITY_LB_NAT)
 402     s->flags |= SNAT_SESSION_FLAG_AFFINITY;
 403   s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 404   s->out2in.addr = o2i_addr;
 405   s->out2in.port = o2i_port;
 406   s->out2in.fib_index = o2i_fib_index;
 407   s->in2out.addr = i2o_addr;
 408   s->in2out.port = i2o_port;
 409   s->in2out.fib_index = i2o_fib_index;
 410   s->nat_proto = nat_proto;
 411
 412   if (NAT_PROTOCOL_ICMP == nat_proto)
 413     {
 414       nat_6t_o2i_flow_init (sm, thread_index, s, s->ext_host_addr, o2i_port,
 415                             o2i_addr, o2i_port, o2i_fib_index, ip->protocol);
 416       nat_6t_flow_icmp_id_rewrite_set (&s->o2i, i2o_port);
 417     }
 418   else
 419     {
 420       nat_6t_o2i_flow_init (sm, thread_index, s, s->ext_host_addr,
 421                             s->ext_host_port, o2i_addr, o2i_port,
 422                             o2i_fib_index, ip->protocol);
 423       nat_6t_flow_dport_rewrite_set (&s->o2i, i2o_port);
 424     }
 425   nat_6t_flow_daddr_rewrite_set (&s->o2i, i2o_addr.as_u32);
 426   nat_6t_flow_txfib_rewrite_set (&s->o2i, i2o_fib_index);
 427
 428   if (nat_ed_ses_o2i_flow_hash_add_del (sm, thread_index, s, 1))
 429     {
 430       b->error = node->errors[NAT_OUT2IN_ED_ERROR_HASH_ADD_FAILED];
 431       nat_ed_session_delete (sm, s, thread_index, 1);
 432       nat_elog_warn (sm, "out2in flow hash add failed");
 433       return 0;
 434     }
 435
 436   if (twice_nat == TWICE_NAT || (twice_nat == TWICE_NAT_SELF &&
 437                                  ip->src_address.as_u32 == i2o_addr.as_u32))
 438     {
 439       int rc = 0;
 440       snat_address_t *filter = 0;
 441
 442       // if exact address is specified use this address
 443       if (is_exact_address (mapping))
 444         {
 445           snat_address_t *ap;
 446           vec_foreach (ap, sm->twice_nat_addresses)
 447           {
 448             if (mapping->pool_addr.as_u32 == ap->addr.as_u32)
 449               {
 450                 filter = ap;
 451                 break;
 452               }
 453           }
 454         }
 455
 456       if (filter)
 457         {
 458           rc = nat_alloc_addr_and_port_exact (filter,
 459                                               thread_index,
 460                                               nat_proto,
 461                                               &s->ext_host_nat_addr,
 462                                               &s->ext_host_nat_port,
 463                                               sm->port_per_thread,
 464                                               tsm->snat_thread_index);
 465           s->flags |= SNAT_SESSION_FLAG_EXACT_ADDRESS;
 466         }
 467       else
 468         {
 469           rc = nat44_ed_alloc_outside_addr_and_port (
 470             sm->twice_nat_addresses, 0, thread_index, nat_proto,
 471             &s->ext_host_nat_addr, &s->ext_host_nat_port, sm->port_per_thread,
 472             tsm->snat_thread_index);
 473         }
 474
 475       if (rc)
 476         {
 477           b->error = node->errors[NAT_OUT2IN_ED_ERROR_OUT_OF_PORTS];
 478           if (nat_ed_ses_o2i_flow_hash_add_del (sm, thread_index, s, 0))
 479             {
 480               nat_elog_warn (sm, "out2in flow hash del failed");
 481             }
 482           snat_free_outside_address_and_port (
 483             sm->twice_nat_addresses, thread_index, &s->ext_host_nat_addr,
 484             s->ext_host_nat_port, s->nat_proto);
 485           nat_ed_session_delete (sm, s, thread_index, 1);
 486           return 0;
 487         }
 488
 489       s->flags |= SNAT_SESSION_FLAG_TWICE_NAT;
 490
 491       nat_6t_flow_saddr_rewrite_set (&s->o2i, s->ext_host_nat_addr.as_u32);
 492       if (NAT_PROTOCOL_ICMP == nat_proto)
 493         {
 494           nat_6t_flow_icmp_id_rewrite_set (&s->o2i, s->ext_host_nat_port);
 495         }
 496       else
 497         {
 498           nat_6t_flow_sport_rewrite_set (&s->o2i, s->ext_host_nat_port);
 499         }
 500
 501       nat_6t_l3_l4_csum_calc (&s->o2i);
 502
 503       nat_6t_i2o_flow_init (sm, thread_index, s, i2o_addr, i2o_port,
 504                             s->ext_host_nat_addr, s->ext_host_nat_port,
 505                             i2o_fib_index, ip->protocol);
 506       nat_6t_flow_daddr_rewrite_set (&s->i2o, s->ext_host_addr.as_u32);
 507       if (NAT_PROTOCOL_ICMP == nat_proto)
 508         {
 509           nat_6t_flow_icmp_id_rewrite_set (&s->i2o, s->ext_host_port);
 510         }
 511       else
 512         {
 513           nat_6t_flow_dport_rewrite_set (&s->i2o, s->ext_host_port);
 514         }
 515     }
 516   else
 517     {
 518       if (NAT_PROTOCOL_ICMP == nat_proto)
 519         {
 520           nat_6t_i2o_flow_init (sm, thread_index, s, i2o_addr, i2o_port,
 521                                 s->ext_host_addr, i2o_port, i2o_fib_index,
 522                                 ip->protocol);
 523         }
 524       else
 525         {
 526           nat_6t_i2o_flow_init (sm, thread_index, s, i2o_addr, i2o_port,
 527                                 s->ext_host_addr, s->ext_host_port,
 528                                 i2o_fib_index, ip->protocol);
 529         }
 530     }
 531
 532   nat_6t_flow_saddr_rewrite_set (&s->i2o, o2i_addr.as_u32);
 533   if (NAT_PROTOCOL_ICMP == nat_proto)
 534     {
 535       nat_6t_flow_icmp_id_rewrite_set (&s->i2o, o2i_port);
 536     }
 537   else
 538     {
 539       nat_6t_flow_sport_rewrite_set (&s->i2o, o2i_port);
 540     }
 541
 542   if (nat_ed_ses_i2o_flow_hash_add_del (sm, thread_index, s, 1))
 543     {
 544       nat_elog_notice (sm, "in2out flow hash add failed");
 545       if (nat_ed_ses_o2i_flow_hash_add_del (sm, thread_index, s, 0))
 546         {
 547           nat_elog_warn (sm, "out2in flow hash del failed");
 548         }
 549       nat_ed_session_delete (sm, s, thread_index, 1);
 550       return 0;
 551     }
 552
 553   nat_ipfix_logging_nat44_ses_create (thread_index,
 554                                       s->in2out.addr.as_u32,
 555                                       s->out2in.addr.as_u32,
 556                                       s->nat_proto,
 557                                       s->in2out.port,
 558                                       s->out2in.port, s->in2out.fib_index);
 559
 560   nat_syslog_nat44_sadd (0, s->in2out.fib_index, &s->in2out.addr,
 561                          s->in2out.port, &s->ext_host_nat_addr,
 562                          s->ext_host_nat_port, &s->out2in.addr, s->out2in.port,
 563                          &s->ext_host_addr, s->ext_host_port, s->nat_proto,
 564                          is_twice_nat_session (s));
 565
 566   per_vrf_sessions_register_session (s, thread_index);
 567
 568   return s;
 569 }
 570
 571 static void
 572 create_bypass_for_fwd (snat_main_t *sm, vlib_buffer_t *b, snat_session_t *s,
 573                        ip4_header_t *ip, u32 rx_fib_index, u32 thread_index)
 574 {
 575   clib_bihash_kv_16_8_t kv, value;
 576   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 577   vlib_main_t *vm = vlib_get_main ();
 578   f64 now = vlib_time_now (vm);
 579   u16 lookup_sport, lookup_dport;
 580   u8 lookup_protocol;
 581   ip4_address_t lookup_saddr, lookup_daddr;
 582
 583   if (ip->protocol == IP_PROTOCOL_ICMP)
 584     {
 585       if (nat_get_icmp_session_lookup_values (b, ip, &lookup_saddr,
 586                                               &lookup_sport, &lookup_daddr,
 587                                               &lookup_dport, &lookup_protocol))
 588         return;
 589     }
 590   else
 591     {
 592       if (ip->protocol == IP_PROTOCOL_UDP || ip->protocol == IP_PROTOCOL_TCP)
 593         {
 594           lookup_sport = vnet_buffer (b)->ip.reass.l4_dst_port;
 595           lookup_dport = vnet_buffer (b)->ip.reass.l4_src_port;
 596         }
 597       else
 598         {
 599           lookup_sport = 0;
 600           lookup_dport = 0;
 601         }
 602       lookup_saddr.as_u32 = ip->dst_address.as_u32;
 603       lookup_daddr.as_u32 = ip->src_address.as_u32;
 604       lookup_protocol = ip->protocol;
 605     }
 606
 607   init_ed_k (&kv, lookup_saddr, lookup_sport, lookup_daddr, lookup_dport,
 608              rx_fib_index, lookup_protocol);
 609
 610   if (!clib_bihash_search_16_8 (&sm->flow_hash, &kv, &value))
 611     {
 612       ASSERT (thread_index == ed_value_get_thread_index (&value));
 613       s =
 614         pool_elt_at_index (tsm->sessions,
 615                            ed_value_get_session_index (&value));
 616     }
 617   else if (ip->protocol == IP_PROTOCOL_ICMP &&
 618            icmp_type_is_error_message
 619            (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags))
 620     {
 621       return;
 622     }
 623   else
 624     {
 625       u32 proto;
 626
 627       if (PREDICT_FALSE
 628           (nat44_ed_maximum_sessions_exceeded
 629            (sm, rx_fib_index, thread_index)))
 630         return;
 631
 632       s = nat_ed_session_alloc (sm, thread_index, now, ip->protocol);
 633       if (!s)
 634         {
 635           nat_elog_warn (sm, "create NAT session failed");
 636           return;
 637         }
 638
 639       proto = ip_proto_to_nat_proto (ip->protocol);
 640
 641       s->ext_host_addr = ip->src_address;
 642       s->ext_host_port = lookup_dport;
 643       s->flags |= SNAT_SESSION_FLAG_FWD_BYPASS;
 644       s->out2in.addr = ip->dst_address;
 645       s->out2in.port = lookup_sport;
 646       s->nat_proto = proto;
 647       if (proto == NAT_PROTOCOL_OTHER)
 648         {
 649           s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 650           s->out2in.port = ip->protocol;
 651         }
 652       s->out2in.fib_index = rx_fib_index;
 653       s->in2out.addr = s->out2in.addr;
 654       s->in2out.port = s->out2in.port;
 655       s->in2out.fib_index = s->out2in.fib_index;
 656
 657       nat_6t_i2o_flow_init (sm, thread_index, s, ip->dst_address, lookup_sport,
 658                             ip->src_address, lookup_dport, rx_fib_index,
 659                             ip->protocol);
 660       nat_6t_flow_txfib_rewrite_set (&s->i2o, rx_fib_index);
 661       if (nat_ed_ses_i2o_flow_hash_add_del (sm, thread_index, s, 1))
 662         {
 663           nat_elog_notice (sm, "in2out flow add failed");
 664           nat_ed_session_delete (sm, s, thread_index, 1);
 665           return;
 666         }
 667
 668       per_vrf_sessions_register_session (s, thread_index);
 669     }
 670
 671   if (ip->protocol == IP_PROTOCOL_TCP)
 672     {
 673       tcp_header_t *tcp = ip4_next_header (ip);
 674       nat44_set_tcp_session_state_o2i (sm, now, s, tcp->flags,
 675                                        tcp->ack_number, tcp->seq_number,
 676                                        thread_index);
 677     }
 678
 679   /* Accounting */
 680   nat44_session_update_counters (s, now, 0, thread_index);
 681   /* Per-user LRU list maintenance */
 682   nat44_session_update_lru (sm, s, thread_index);
 683 }
 684
 685 static snat_session_t *
 686 nat44_ed_out2in_slowpath_unknown_proto (snat_main_t *sm, vlib_buffer_t *b,
 687                                         ip4_header_t *ip, u32 rx_fib_index,
 688                                         u32 thread_index, f64 now,
 689                                         vlib_main_t *vm,
 690                                         vlib_node_runtime_t *node)
 691 {
 692   clib_bihash_kv_8_8_t kv, value;
 693   snat_static_mapping_t *m;
 694   snat_session_t *s;
 695
 696   if (PREDICT_FALSE (
 697         nat44_ed_maximum_sessions_exceeded (sm, rx_fib_index, thread_index)))
 698     {
 699       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 700       nat_elog_notice (sm, "maximum sessions exceeded");
 701       return 0;
 702     }
 703
 704   init_nat_k (&kv, ip->dst_address, 0, 0, 0);
 705   if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
 706     {
 707       b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 708       return 0;
 709     }
 710
 711   m = pool_elt_at_index (sm->static_mappings, value.value);
 712
 713   /* Create a new session */
 714   s = nat_ed_session_alloc (sm, thread_index, now, ip->protocol);
 715   if (!s)
 716     {
 717       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 718       nat_elog_warn (sm, "create NAT session failed");
 719       return 0;
 720     }
 721
 722   s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 723   s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 724   s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 725   s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 726   s->out2in.addr.as_u32 = ip->dst_address.as_u32;
 727   s->out2in.fib_index = rx_fib_index;
 728   s->in2out.addr.as_u32 = m->local_addr.as_u32;
 729   s->in2out.fib_index = m->fib_index;
 730   s->in2out.port = s->out2in.port = ip->protocol;
 731
 732   nat_6t_o2i_flow_init (sm, thread_index, s, ip->dst_address, 0,
 733                         ip->src_address, 0, m->fib_index, ip->protocol);
 734   nat_6t_flow_saddr_rewrite_set (&s->i2o, ip->dst_address.as_u32);
 735   if (nat_ed_ses_i2o_flow_hash_add_del (sm, thread_index, s, 1))
 736     {
 737       nat_elog_notice (sm, "in2out key add failed");
 738       nat_ed_session_delete (sm, s, thread_index, 1);
 739       return NULL;
 740     }
 741
 742   nat_6t_o2i_flow_init (sm, thread_index, s, ip->src_address, 0,
 743                         ip->dst_address, 0, rx_fib_index, ip->protocol);
 744   nat_6t_flow_daddr_rewrite_set (&s->o2i, m->local_addr.as_u32);
 745   nat_6t_flow_txfib_rewrite_set (&s->o2i, m->fib_index);
 746   if (nat_ed_ses_o2i_flow_hash_add_del (sm, thread_index, s, 1))
 747     {
 748       nat_elog_notice (sm, "out2in flow hash add failed");
 749       nat_ed_session_delete (sm, s, thread_index, 1);
 750       return NULL;
 751     }
 752
 753   per_vrf_sessions_register_session (s, thread_index);
 754
 755   /* Accounting */
 756   nat44_session_update_counters (s, now, vlib_buffer_length_in_chain (vm, b),
 757                                  thread_index);
 758   /* Per-user LRU list maintenance */
 759   nat44_session_update_lru (sm, s, thread_index);
 760
 761   return s;
 762 }
 763
 764 static inline uword
 765 nat44_ed_out2in_fast_path_node_fn_inline (vlib_main_t * vm,
 766                                           vlib_node_runtime_t * node,
 767                                           vlib_frame_t * frame,
 768                                           int is_multi_worker)
 769 {
 770   u32 n_left_from, *from;
 771   snat_main_t *sm = &snat_main;
 772   f64 now = vlib_time_now (vm);
 773   u32 thread_index = vm->thread_index;
 774   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 775
 776   from = vlib_frame_vector_args (frame);
 777   n_left_from = frame->n_vectors;
 778
 779   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b = bufs;
 780   u16 nexts[VLIB_FRAME_SIZE], *next = nexts;
 781   vlib_get_buffers (vm, from, b, n_left_from);
 782
 783   while (n_left_from > 0)
 784     {
 785       vlib_buffer_t *b0;
 786       u32 sw_if_index0, rx_fib_index0;
 787       nat_protocol_t proto0;
 788       ip4_header_t *ip0;
 789       snat_session_t *s0 = 0;
 790       clib_bihash_kv_16_8_t kv0, value0;
 791       nat_translation_error_e translation_error = NAT_ED_TRNSL_ERR_SUCCESS;
 792       nat_6t_flow_t *f = 0;
 793       nat_6t_t lookup;
 794       int lookup_skipped = 0;
 795
 796       b0 = *b;
 797       b++;
 798
 799       /* Prefetch next iteration. */
 800       if (PREDICT_TRUE (n_left_from >= 2))
 801         {
 802           vlib_buffer_t *p2;
 803
 804           p2 = *b;
 805
 806           vlib_prefetch_buffer_header (p2, LOAD);
 807
 808           CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, LOAD);
 809         }
 810
 811       next[0] = vnet_buffer2 (b0)->nat.arc_next;
 812
 813       lookup.sport = vnet_buffer (b0)->ip.reass.l4_src_port;
 814       lookup.dport = vnet_buffer (b0)->ip.reass.l4_dst_port;
 815
 816       vnet_buffer (b0)->snat.flags = 0;
 817       ip0 = vlib_buffer_get_current (b0);
 818
 819       sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 820       rx_fib_index0 =
 821         fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4, sw_if_index0);
 822
 823       lookup.fib_index = rx_fib_index0;
 824
 825       if (PREDICT_FALSE (ip0->ttl == 1))
 826         {
 827           vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 828           icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 829                                        ICMP4_time_exceeded_ttl_exceeded_in_transit,
 830                                        0);
 831           next[0] = NAT_NEXT_ICMP_ERROR;
 832           goto trace0;
 833         }
 834
 835       proto0 = ip_proto_to_nat_proto (ip0->protocol);
 836
 837       if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
 838         {
 839           if (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
 840                 ICMP4_echo_request &&
 841               vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
 842                 ICMP4_echo_reply &&
 843               !icmp_type_is_error_message (
 844                 vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags))
 845             {
 846               b0->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 847               next[0] = NAT_NEXT_DROP;
 848               goto trace0;
 849             }
 850           int err = nat_get_icmp_session_lookup_values (
 851             b0, ip0, &lookup.saddr, &lookup.sport, &lookup.daddr,
 852             &lookup.dport, &lookup.proto);
 853           if (err != 0)
 854             {
 855               b0->error = node->errors[err];
 856               next[0] = NAT_NEXT_DROP;
 857               goto trace0;
 858             }
 859         }
 860       else
 861         {
 862           lookup.saddr.as_u32 = ip0->src_address.as_u32;
 863           lookup.daddr.as_u32 = ip0->dst_address.as_u32;
 864           lookup.proto = ip0->protocol;
 865         }
 866
 867       /* there might be a stashed index in vnet_buffer2 from handoff or
 868        * classify node, see if it can be used */
 869       if (is_multi_worker &&
 870           !pool_is_free_index (tsm->sessions,
 871                                vnet_buffer2 (b0)->nat.cached_session_index))
 872         {
 873           s0 = pool_elt_at_index (tsm->sessions,
 874                                   vnet_buffer2 (b0)->nat.cached_session_index);
 875           if (PREDICT_TRUE (nat_6t_t_eq (&s0->o2i.match, &lookup)) ||
 876               (s0->flags & SNAT_SESSION_FLAG_TWICE_NAT &&
 877                nat_6t_t_eq (&s0->i2o.match, &lookup)))
 878             {
 879               /* yes, this is the droid we're looking for */
 880               lookup_skipped = 1;
 881               goto skip_lookup;
 882             }
 883           s0 = NULL;
 884         }
 885
 886       init_ed_k (&kv0, lookup.saddr, lookup.sport, lookup.daddr, lookup.dport,
 887                  lookup.fib_index, lookup.proto);
 888
 889       // lookup flow
 890       if (clib_bihash_search_16_8 (&sm->flow_hash, &kv0, &value0))
 891         {
 892           // flow does not exist go slow path
 893           next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 894           goto trace0;
 895         }
 896       ASSERT (thread_index == ed_value_get_thread_index (&value0));
 897       s0 =
 898         pool_elt_at_index (tsm->sessions,
 899                            ed_value_get_session_index (&value0));
 900     skip_lookup:
 901
 902       if (PREDICT_FALSE (per_vrf_sessions_is_expired (s0, thread_index)))
 903         {
 904           // session is closed, go slow path
 905           nat_free_session_data (sm, s0, thread_index, 0);
 906           nat_ed_session_delete (sm, s0, thread_index, 1);
 907           next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 908           goto trace0;
 909         }
 910
 911       if (s0->tcp_closed_timestamp)
 912         {
 913           if (now >= s0->tcp_closed_timestamp)
 914             {
 915               // session is closed, go slow path, freed in slow path
 916               next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 917             }
 918           else
 919             {
 920               // session in transitory timeout, drop
 921               b0->error = node->errors[NAT_OUT2IN_ED_ERROR_TCP_CLOSED];
 922               next[0] = NAT_NEXT_DROP;
 923             }
 924           goto trace0;
 925         }
 926
 927       // drop if session expired
 928       u64 sess_timeout_time;
 929       sess_timeout_time =
 930         s0->last_heard + (f64) nat44_session_get_timeout (sm, s0);
 931       if (now >= sess_timeout_time)
 932         {
 933           // session is closed, go slow path
 934           nat_free_session_data (sm, s0, thread_index, 0);
 935           nat_ed_session_delete (sm, s0, thread_index, 1);
 936           next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 937           goto trace0;
 938         }
 939
 940       if (nat_6t_t_eq (&s0->o2i.match, &lookup))
 941         {
 942           f = &s0->o2i;
 943         }
 944       else if (s0->flags & SNAT_SESSION_FLAG_TWICE_NAT &&
 945                nat_6t_t_eq (&s0->i2o.match, &lookup))
 946         {
 947           f = &s0->i2o;
 948         }
 949       else
 950         {
 951           /*
 952            * Send DHCP packets to the ipv4 stack, or we won't
 953            * be able to use dhcp client on the outside interface
 954            */
 955           if (PREDICT_FALSE (
 956                 proto0 == NAT_PROTOCOL_UDP &&
 957                 (vnet_buffer (b0)->ip.reass.l4_dst_port ==
 958                  clib_host_to_net_u16 (UDP_DST_PORT_dhcp_to_client))))
 959             {
 960               goto trace0;
 961             }
 962
 963           if (!sm->forwarding_enabled)
 964             {
 965               b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 966               next[0] = NAT_NEXT_DROP;
 967               goto trace0;
 968             }
 969           else
 970             {
 971               if (nat_6t_t_eq (&s0->i2o.match, &lookup))
 972                 {
 973                   f = &s0->i2o;
 974                 }
 975               else
 976                 {
 977                   // FIXME TODO bypass ???
 978                   //  create_bypass_for_fwd (sm, b0, s0, ip0, rx_fib_index0,
 979                   //                       thread_index);
 980                   translation_error = NAT_ED_TRNSL_ERR_FLOW_MISMATCH;
 981                   nat_free_session_data (sm, s0, thread_index, 0);
 982                   nat_ed_session_delete (sm, s0, thread_index, 1);
 983                   next[0] = NAT_NEXT_DROP;
 984                   goto trace0;
 985                 }
 986             }
 987         }
 988
 989       if (NAT_ED_TRNSL_ERR_SUCCESS !=
 990           (translation_error = nat_6t_flow_buf_translate (
 991              sm, b0, ip0, f, proto0, 0 /* is_output_feature */)))
 992         {
 993           next[0] = NAT_NEXT_DROP;
 994           goto trace0;
 995         }
 996
 997       switch (proto0)
 998         {
 999         case NAT_PROTOCOL_TCP:
1000           vlib_increment_simple_counter (&sm->counters.fastpath.out2in.tcp,
1001                                          thread_index, sw_if_index0, 1);
1002           nat44_set_tcp_session_state_o2i (sm, now, s0,
1003                                            vnet_buffer (b0)->ip.
1004                                            reass.icmp_type_or_tcp_flags,
1005                                            vnet_buffer (b0)->ip.
1006                                            reass.tcp_ack_number,
1007                                            vnet_buffer (b0)->ip.
1008                                            reass.tcp_seq_number,
1009                                            thread_index);
1010           break;
1011         case NAT_PROTOCOL_UDP:
1012           vlib_increment_simple_counter (&sm->counters.fastpath.out2in.udp,
1013                                          thread_index, sw_if_index0, 1);
1014           break;
1015         case NAT_PROTOCOL_ICMP:
1016           vlib_increment_simple_counter (&sm->counters.fastpath.out2in.icmp,
1017                                          thread_index, sw_if_index0, 1);
1018           break;
1019         case NAT_PROTOCOL_OTHER:
1020           vlib_increment_simple_counter (&sm->counters.fastpath.out2in.other,
1021                                          thread_index, sw_if_index0, 1);
1022           break;
1023         }
1024
1025       /* Accounting */
1026       nat44_session_update_counters (s0, now,
1027                                      vlib_buffer_length_in_chain (vm, b0),
1028                                      thread_index);
1029       /* Per-user LRU list maintenance */
1030       nat44_session_update_lru (sm, s0, thread_index);
1031
1032     trace0:
1033       if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1034                          && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1035         {
1036           nat44_ed_out2in_trace_t *t =
1037             vlib_add_trace (vm, node, b0, sizeof (*t));
1038           t->sw_if_index = sw_if_index0;
1039           t->next_index = next[0];
1040           t->is_slow_path = 0;
1041           t->translation_error = translation_error;
1042           clib_memcpy (&t->search_key, &kv0, sizeof (t->search_key));
1043           t->lookup_skipped = lookup_skipped;
1044
1045           if (s0)
1046             {
1047               t->session_index = s0 - tsm->sessions;
1048               clib_memcpy (&t->i2of, &s0->i2o, sizeof (t->i2of));
1049               clib_memcpy (&t->o2if, &s0->o2i, sizeof (t->o2if));
1050               t->translation_via_i2of = (&s0->i2o == f);
1051             }
1052           else
1053             {
1054               t->session_index = ~0;
1055             }
1056         }
1057
1058       if (next[0] == NAT_NEXT_DROP)
1059         {
1060           vlib_increment_simple_counter (&sm->counters.fastpath.out2in.drops,
1061                                          thread_index, sw_if_index0, 1);
1062         }
1063
1064       n_left_from--;
1065       next++;
1066     }
1067
1068   vlib_buffer_enqueue_to_next (vm, node, from, (u16 *) nexts,
1069                                frame->n_vectors);
1070   return frame->n_vectors;
1071 }
1072
1073 static inline uword
1074 nat44_ed_out2in_slow_path_node_fn_inline (vlib_main_t * vm,
1075                                           vlib_node_runtime_t * node,
1076                                           vlib_frame_t * frame)
1077 {
1078   u32 n_left_from, *from;
1079   snat_main_t *sm = &snat_main;
1080   f64 now = vlib_time_now (vm);
1081   u32 thread_index = vm->thread_index;
1082   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
1083   snat_static_mapping_t *m;
1084
1085   from = vlib_frame_vector_args (frame);
1086   n_left_from = frame->n_vectors;
1087
1088   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b = bufs;
1089   u16 nexts[VLIB_FRAME_SIZE], *next = nexts;
1090   vlib_get_buffers (vm, from, b, n_left_from);
1091
1092   while (n_left_from > 0)
1093     {
1094       vlib_buffer_t *b0;
1095       u32 sw_if_index0, rx_fib_index0;
1096       nat_protocol_t proto0;
1097       ip4_header_t *ip0;
1098       udp_header_t *udp0;
1099       icmp46_header_t *icmp0;
1100       snat_session_t *s0 = 0;
1101       clib_bihash_kv_16_8_t kv0, value0;
1102       lb_nat_type_t lb_nat0;
1103       twice_nat_type_t twice_nat0;
1104       u8 identity_nat0;
1105       ip4_address_t sm_addr;
1106       u16 sm_port;
1107       u32 sm_fib_index;
1108       nat_translation_error_e translation_error = NAT_ED_TRNSL_ERR_SUCCESS;
1109
1110       b0 = *b;
1111       next[0] = vnet_buffer2 (b0)->nat.arc_next;
1112
1113       vnet_buffer (b0)->snat.flags = 0;
1114       ip0 = vlib_buffer_get_current (b0);
1115
1116       sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1117       rx_fib_index0 =
1118         fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4, sw_if_index0);
1119
1120       if (PREDICT_FALSE (ip0->ttl == 1))
1121         {
1122           vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1123           icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1124                                        ICMP4_time_exceeded_ttl_exceeded_in_transit,
1125                                        0);
1126           next[0] = NAT_NEXT_ICMP_ERROR;
1127           goto trace0;
1128         }
1129
1130       udp0 = ip4_next_header (ip0);
1131       icmp0 = (icmp46_header_t *) udp0;
1132       proto0 = ip_proto_to_nat_proto (ip0->protocol);
1133
1134       if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
1135         {
1136           s0 = nat44_ed_out2in_slowpath_unknown_proto (
1137             sm, b0, ip0, rx_fib_index0, thread_index, now, vm, node);
1138           if (!sm->forwarding_enabled)
1139             {
1140               if (!s0)
1141                 next[0] = NAT_NEXT_DROP;
1142             }
1143           if (NAT_NEXT_DROP != next[0] &&
1144               NAT_ED_TRNSL_ERR_SUCCESS !=
1145                 (translation_error = nat_6t_flow_buf_translate (
1146                    sm, b0, ip0, &s0->o2i, proto0, 0 /* is_output_feature */)))
1147             {
1148               goto trace0;
1149             }
1150
1151           vlib_increment_simple_counter (&sm->counters.slowpath.out2in.other,
1152                                          thread_index, sw_if_index0, 1);
1153           goto trace0;
1154         }
1155
1156       if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
1157         {
1158           next[0] = icmp_out2in_ed_slow_path
1159             (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1160              next[0], now, thread_index, &s0);
1161
1162           if (NAT_NEXT_DROP != next[0] && s0 &&
1163               NAT_ED_TRNSL_ERR_SUCCESS !=
1164                 (translation_error = nat_6t_flow_buf_translate (
1165                    sm, b0, ip0, &s0->o2i, proto0, 0 /* is_output_feature */)))
1166             {
1167               goto trace0;
1168             }
1169
1170           vlib_increment_simple_counter (&sm->counters.slowpath.out2in.icmp,
1171                                          thread_index, sw_if_index0, 1);
1172           goto trace0;
1173         }
1174
1175       init_ed_k (&kv0, ip0->src_address,
1176                  vnet_buffer (b0)->ip.reass.l4_src_port, ip0->dst_address,
1177                  vnet_buffer (b0)->ip.reass.l4_dst_port, rx_fib_index0,
1178                  ip0->protocol);
1179
1180       s0 = NULL;
1181       if (!clib_bihash_search_16_8 (&sm->flow_hash, &kv0, &value0))
1182         {
1183           ASSERT (thread_index == ed_value_get_thread_index (&value0));
1184           s0 =
1185             pool_elt_at_index (tsm->sessions,
1186                                ed_value_get_session_index (&value0));
1187
1188           if (s0->tcp_closed_timestamp && now >= s0->tcp_closed_timestamp)
1189             {
1190               nat_free_session_data (sm, s0, thread_index, 0);
1191               nat_ed_session_delete (sm, s0, thread_index, 1);
1192               s0 = NULL;
1193             }
1194         }
1195
1196       if (!s0)
1197         {
1198           /* Try to match static mapping by external address and port,
1199              destination address and port in packet */
1200
1201           if (snat_static_mapping_match (
1202                 vm, sm, ip0->dst_address,
1203                 vnet_buffer (b0)->ip.reass.l4_dst_port, rx_fib_index0, proto0,
1204                 &sm_addr, &sm_port, &sm_fib_index, 1, 0, &twice_nat0, &lb_nat0,
1205                 &ip0->src_address, &identity_nat0, &m))
1206             {
1207               /*
1208                * Send DHCP packets to the ipv4 stack, or we won't
1209                * be able to use dhcp client on the outside interface
1210                */
1211               if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_UDP
1212                                  && (vnet_buffer (b0)->ip.reass.l4_dst_port ==
1213                                      clib_host_to_net_u16
1214                                      (UDP_DST_PORT_dhcp_to_client))))
1215                 {
1216                   goto trace0;
1217                 }
1218
1219               if (!sm->forwarding_enabled)
1220                 {
1221                   b0->error =
1222                     node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
1223                   next[0] = NAT_NEXT_DROP;
1224                 }
1225               else
1226                 {
1227                   if (next_src_nat
1228                       (sm, ip0, vnet_buffer (b0)->ip.reass.l4_src_port,
1229                        vnet_buffer (b0)->ip.reass.l4_dst_port,
1230                        thread_index, rx_fib_index0))
1231                     {
1232                       next[0] = NAT_NEXT_IN2OUT_ED_FAST_PATH;
1233                     }
1234                   else
1235                     {
1236                       create_bypass_for_fwd (sm, b0, s0, ip0, rx_fib_index0,
1237                                              thread_index);
1238                     }
1239                 }
1240               goto trace0;
1241             }
1242
1243           if (PREDICT_FALSE (identity_nat0))
1244             goto trace0;
1245
1246           if ((proto0 == NAT_PROTOCOL_TCP)
1247               && !tcp_flags_is_init (vnet_buffer (b0)->ip.
1248                                      reass.icmp_type_or_tcp_flags))
1249             {
1250               b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
1251               next[0] = NAT_NEXT_DROP;
1252               goto trace0;
1253             }
1254
1255           /* Create session initiated by host from external network */
1256           s0 = create_session_for_static_mapping_ed (sm, b0,
1257                                                      sm_addr, sm_port,
1258                                                      sm_fib_index,
1259                                                      ip0->dst_address,
1260                                                      vnet_buffer (b0)->
1261                                                      ip.reass.l4_dst_port,
1262                                                      rx_fib_index0, proto0,
1263                                                      node, rx_fib_index0,
1264                                                      thread_index, twice_nat0,
1265                                                      lb_nat0, now, m);
1266           if (!s0)
1267             {
1268               next[0] = NAT_NEXT_DROP;
1269               goto trace0;
1270             }
1271         }
1272
1273       if (NAT_ED_TRNSL_ERR_SUCCESS !=
1274           (translation_error = nat_6t_flow_buf_translate (
1275              sm, b0, ip0, &s0->o2i, proto0, 0 /* is_output_feature */)))
1276         {
1277           next[0] = NAT_NEXT_DROP;
1278           goto trace0;
1279         }
1280
1281       if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
1282         {
1283           vlib_increment_simple_counter (&sm->counters.slowpath.out2in.tcp,
1284                                          thread_index, sw_if_index0, 1);
1285           nat44_set_tcp_session_state_o2i (sm, now, s0,
1286                                            vnet_buffer (b0)->ip.
1287                                            reass.icmp_type_or_tcp_flags,
1288                                            vnet_buffer (b0)->ip.
1289                                            reass.tcp_ack_number,
1290                                            vnet_buffer (b0)->ip.
1291                                            reass.tcp_seq_number,
1292                                            thread_index);
1293         }
1294       else
1295         {
1296           vlib_increment_simple_counter (&sm->counters.slowpath.out2in.udp,
1297                                          thread_index, sw_if_index0, 1);
1298         }
1299
1300       /* Accounting */
1301       nat44_session_update_counters (s0, now,
1302                                      vlib_buffer_length_in_chain (vm, b0),
1303                                      thread_index);
1304       /* Per-user LRU list maintenance */
1305       nat44_session_update_lru (sm, s0, thread_index);
1306
1307     trace0:
1308       if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1309                          && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1310         {
1311           nat44_ed_out2in_trace_t *t =
1312             vlib_add_trace (vm, node, b0, sizeof (*t));
1313           t->sw_if_index = sw_if_index0;
1314           t->next_index = next[0];
1315           t->is_slow_path = 1;
1316           t->translation_error = translation_error;
1317           clib_memcpy (&t->search_key, &kv0, sizeof (t->search_key));
1318
1319           if (s0)
1320             {
1321               t->session_index = s0 - tsm->sessions;
1322               clib_memcpy (&t->i2of, &s0->i2o, sizeof (t->i2of));
1323               clib_memcpy (&t->o2if, &s0->o2i, sizeof (t->o2if));
1324             }
1325           else
1326             {
1327               t->session_index = ~0;
1328             }
1329         }
1330
1331       if (next[0] == NAT_NEXT_DROP)
1332         {
1333           vlib_increment_simple_counter (&sm->counters.slowpath.out2in.drops,
1334                                          thread_index, sw_if_index0, 1);
1335         }
1336
1337       n_left_from--;
1338       next++;
1339       b++;
1340     }
1341
1342   vlib_buffer_enqueue_to_next (vm, node, from, (u16 *) nexts,
1343                                frame->n_vectors);
1344
1345   return frame->n_vectors;
1346 }
1347
1348 VLIB_NODE_FN (nat44_ed_out2in_node) (vlib_main_t * vm,
1349                                      vlib_node_runtime_t * node,
1350                                      vlib_frame_t * frame)
1351 {
1352   if (snat_main.num_workers > 1)
1353     {
1354       return nat44_ed_out2in_fast_path_node_fn_inline (vm, node, frame, 1);
1355     }
1356   else
1357     {
1358       return nat44_ed_out2in_fast_path_node_fn_inline (vm, node, frame, 0);
1359     }
1360 }
1361
1362 /* *INDENT-OFF* */
1363 VLIB_REGISTER_NODE (nat44_ed_out2in_node) = {
1364   .name = "nat44-ed-out2in",
1365   .vector_size = sizeof (u32),
1366   .sibling_of = "nat-default",
1367   .format_trace = format_nat44_ed_out2in_trace,
1368   .type = VLIB_NODE_TYPE_INTERNAL,
1369   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1370   .error_strings = nat_out2in_ed_error_strings,
1371   .runtime_data_bytes = sizeof (snat_runtime_t),
1372 };
1373 /* *INDENT-ON* */
1374
1375 VLIB_NODE_FN (nat44_ed_out2in_slowpath_node) (vlib_main_t * vm,
1376                                               vlib_node_runtime_t * node,
1377                                               vlib_frame_t * frame)
1378 {
1379   return nat44_ed_out2in_slow_path_node_fn_inline (vm, node, frame);
1380 }
1381
1382 /* *INDENT-OFF* */
1383 VLIB_REGISTER_NODE (nat44_ed_out2in_slowpath_node) = {
1384   .name = "nat44-ed-out2in-slowpath",
1385   .vector_size = sizeof (u32),
1386   .sibling_of = "nat-default",
1387   .format_trace = format_nat44_ed_out2in_trace,
1388   .type = VLIB_NODE_TYPE_INTERNAL,
1389   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1390   .error_strings = nat_out2in_ed_error_strings,
1391   .runtime_data_bytes = sizeof (snat_runtime_t),
1392 };
1393 /* *INDENT-ON* */
1394
1395 static u8 *
1396 format_nat_pre_trace (u8 * s, va_list * args)
1397 {
1398   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1399   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1400   nat_pre_trace_t *t = va_arg (*args, nat_pre_trace_t *);
1401   return format (s, "out2in next_index %d arc_next_index %d", t->next_index,
1402                  t->arc_next_index);
1403 }
1404
1405 VLIB_NODE_FN (nat_pre_out2in_node) (vlib_main_t * vm,
1406                                     vlib_node_runtime_t * node,
1407                                     vlib_frame_t * frame)
1408 {
1409   return nat_pre_node_fn_inline (vm, node, frame,
1410                                  NAT_NEXT_OUT2IN_ED_FAST_PATH);
1411 }
1412
1413 /* *INDENT-OFF* */
1414 VLIB_REGISTER_NODE (nat_pre_out2in_node) = {
1415   .name = "nat-pre-out2in",
1416   .vector_size = sizeof (u32),
1417   .sibling_of = "nat-default",
1418   .format_trace = format_nat_pre_trace,
1419   .type = VLIB_NODE_TYPE_INTERNAL,
1420   .n_errors = 0,
1421  };
1422 /* *INDENT-ON* */
1423
1424 /*
1425  * fd.io coding-style-patch-verification: ON
1426  *
1427  * Local Variables:
1428  * eval: (c-set-style "gnu")
1429  * End:
1430  */