src/plugins/nat/out2in_ed.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 #include <nat/nat.h>
  28 #include <nat/lib/ipfix_logging.h>
  29 #include <nat/nat_inlines.h>
  30 #include <nat/nat44/inlines.h>
  31 #include <nat/lib/nat_syslog.h>
  32 #include <nat/nat44/ed_inlines.h>
  33
  34 static char *nat_out2in_ed_error_strings[] = {
  35 #define _(sym,string) string,
  36   foreach_nat_out2in_ed_error
  37 #undef _
  38 };
  39
  40 typedef struct
  41 {
  42   u32 sw_if_index;
  43   u32 next_index;
  44   u32 session_index;
  45   nat_translation_error_e translation_error;
  46   nat_6t_flow_t i2of;
  47   nat_6t_flow_t o2if;
  48   clib_bihash_kv_16_8_t search_key;
  49   u8 is_slow_path;
  50   u8 translation_via_i2of;
  51   u8 lookup_skipped;
  52 } nat44_ed_out2in_trace_t;
  53
  54 static u8 *
  55 format_nat44_ed_out2in_trace (u8 * s, va_list * args)
  56 {
  57   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  58   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  59   nat44_ed_out2in_trace_t *t = va_arg (*args, nat44_ed_out2in_trace_t *);
  60   char *tag;
  61
  62   tag =
  63     t->is_slow_path ? "NAT44_OUT2IN_ED_SLOW_PATH" :
  64     "NAT44_OUT2IN_ED_FAST_PATH";
  65
  66   s = format (s, "%s: sw_if_index %d, next index %d, session %d", tag,
  67               t->sw_if_index, t->next_index, t->session_index);
  68   if (~0 != t->session_index)
  69     {
  70       s = format (s, ", translation result '%U' via %s",
  71                   format_nat_ed_translation_error, t->translation_error,
  72                   t->translation_via_i2of ? "i2of" : "o2if");
  73       s = format (s, "\n  i2of %U", format_nat_6t_flow, &t->i2of);
  74       s = format (s, "\n  o2if %U", format_nat_6t_flow, &t->o2if);
  75     }
  76   if (!t->is_slow_path)
  77     {
  78       if (t->lookup_skipped)
  79         {
  80           s = format (s, "\n lookup skipped - cached session index used");
  81         }
  82       else
  83         {
  84           s = format (s, "\n  search key %U", format_ed_session_kvp,
  85                       &t->search_key);
  86         }
  87     }
  88
  89   return s;
  90 }
  91
  92 static int
  93 next_src_nat (snat_main_t *sm, ip4_header_t *ip, u16 src_port, u16 dst_port,
  94               u32 thread_index, u32 rx_fib_index)
  95 {
  96   clib_bihash_kv_16_8_t kv, value;
  97
  98   init_ed_k (&kv, ip->src_address, src_port, ip->dst_address, dst_port,
  99              rx_fib_index, ip->protocol);
 100   if (!clib_bihash_search_16_8 (&sm->flow_hash, &kv, &value))
 101     return 1;
 102
 103   return 0;
 104 }
 105
 106 static void create_bypass_for_fwd (snat_main_t *sm, vlib_buffer_t *b,
 107                                    snat_session_t *s, ip4_header_t *ip,
 108                                    u32 rx_fib_index, u32 thread_index);
 109
 110 static snat_session_t *create_session_for_static_mapping_ed (
 111   snat_main_t *sm, vlib_buffer_t *b, ip4_address_t i2o_addr, u16 i2o_port,
 112   u32 i2o_fib_index, ip4_address_t o2i_addr, u16 o2i_port, u32 o2i_fib_index,
 113   nat_protocol_t nat_proto, vlib_node_runtime_t *node, u32 rx_fib_index,
 114   u32 thread_index, twice_nat_type_t twice_nat, lb_nat_type_t lb_nat, f64 now,
 115   snat_static_mapping_t *mapping);
 116
 117 static inline u32
 118 icmp_out2in_ed_slow_path (snat_main_t *sm, vlib_buffer_t *b, ip4_header_t *ip,
 119                           icmp46_header_t *icmp, u32 sw_if_index,
 120                           u32 rx_fib_index, vlib_node_runtime_t *node,
 121                           u32 next, f64 now, u32 thread_index,
 122                           snat_session_t **s_p)
 123 {
 124   vlib_main_t *vm = vlib_get_main ();
 125
 126   ip_csum_t sum;
 127   u16 checksum;
 128
 129   snat_session_t *s = 0;
 130   u8 is_addr_only, identity_nat;
 131   ip4_address_t sm_addr;
 132   u16 sm_port;
 133   u32 sm_fib_index;
 134   snat_static_mapping_t *m;
 135   u8 lookup_protocol;
 136   ip4_address_t lookup_saddr, lookup_daddr;
 137   u16 lookup_sport, lookup_dport;
 138
 139   sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
 140   rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 141
 142   if (nat_get_icmp_session_lookup_values (b, ip, &lookup_saddr, &lookup_sport,
 143                                           &lookup_daddr, &lookup_dport,
 144                                           &lookup_protocol))
 145     {
 146       b->error = node->errors[NAT_OUT2IN_ED_ERROR_UNSUPPORTED_PROTOCOL];
 147       next = NAT_NEXT_DROP;
 148       goto out;
 149     }
 150
 151   if (snat_static_mapping_match (
 152         sm, ip->dst_address, lookup_sport, rx_fib_index,
 153         ip_proto_to_nat_proto (ip->protocol), &sm_addr, &sm_port,
 154         &sm_fib_index, 1, &is_addr_only, 0, 0, 0, &identity_nat, &m))
 155     {
 156       // static mapping not matched
 157       if (!sm->forwarding_enabled)
 158         {
 159           /* Don't NAT packet aimed at the intfc address */
 160           if (!is_interface_addr (sm, node, sw_if_index,
 161                                   ip->dst_address.as_u32))
 162             {
 163               b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 164               next = NAT_NEXT_DROP;
 165             }
 166         }
 167       else
 168         {
 169           if (next_src_nat (sm, ip, lookup_sport, lookup_dport, thread_index,
 170                             rx_fib_index))
 171             {
 172               next = NAT_NEXT_IN2OUT_ED_FAST_PATH;
 173             }
 174           else
 175             {
 176               create_bypass_for_fwd (sm, b, s, ip, rx_fib_index, thread_index);
 177             }
 178         }
 179       goto out;
 180     }
 181
 182   if (PREDICT_FALSE (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 183                        ICMP4_echo_reply &&
 184                      (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 185                         ICMP4_echo_request ||
 186                       !is_addr_only)))
 187     {
 188       b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 189       next = NAT_NEXT_DROP;
 190       goto out;
 191     }
 192
 193   if (PREDICT_FALSE (identity_nat))
 194     {
 195       goto out;
 196     }
 197
 198   /* Create session initiated by host from external network */
 199   s = create_session_for_static_mapping_ed (
 200     sm, b, sm_addr, sm_port, sm_fib_index, ip->dst_address, lookup_sport,
 201     rx_fib_index, ip_proto_to_nat_proto (lookup_protocol), node, rx_fib_index,
 202     thread_index, 0, 0, vlib_time_now (vm), m);
 203   if (!s)
 204     next = NAT_NEXT_DROP;
 205
 206   if (PREDICT_TRUE (!ip4_is_fragment (ip)))
 207     {
 208       sum = ip_incremental_checksum_buffer (
 209         vm, b, (u8 *) icmp - (u8 *) vlib_buffer_get_current (b),
 210         ntohs (ip->length) - ip4_header_bytes (ip), 0);
 211       checksum = ~ip_csum_fold (sum);
 212       if (checksum != 0 && checksum != 0xffff)
 213         {
 214           next = NAT_NEXT_DROP;
 215           goto out;
 216         }
 217     }
 218
 219   if (PREDICT_TRUE (next != NAT_NEXT_DROP && s))
 220     {
 221       /* Accounting */
 222       nat44_session_update_counters (
 223         s, now, vlib_buffer_length_in_chain (vm, b), thread_index);
 224       /* Per-user LRU list maintenance */
 225       nat44_session_update_lru (sm, s, thread_index);
 226     }
 227 out:
 228   if (NAT_NEXT_DROP == next && s)
 229     {
 230       nat_ed_session_delete (sm, s, thread_index, 1);
 231       s = 0;
 232     }
 233   *s_p = s;
 234   return next;
 235 }
 236
 237 // allocate exact address based on preference
 238 static_always_inline int
 239 nat_alloc_addr_and_port_exact (snat_address_t * a,
 240                                u32 thread_index,
 241                                nat_protocol_t proto,
 242                                ip4_address_t * addr,
 243                                u16 * port,
 244                                u16 port_per_thread, u32 snat_thread_index)
 245 {
 246   u32 portnum;
 247
 248   switch (proto)
 249     {
 250 #define _(N, j, n, s) \
 251     case NAT_PROTOCOL_##N: \
 252       if (a->busy_##n##_ports_per_thread[thread_index] < port_per_thread) \
 253         { \
 254           while (1) \
 255             { \
 256               portnum = (port_per_thread * \
 257                 snat_thread_index) + \
 258                 snat_random_port(0, port_per_thread - 1) + 1024; \
 259               if (a->busy_##n##_port_refcounts[portnum]) \
 260                 continue; \
 261               --a->busy_##n##_port_refcounts[portnum]; \
 262               a->busy_##n##_ports_per_thread[thread_index]++; \
 263               a->busy_##n##_ports++; \
 264               *addr = a->addr; \
 265               *port = clib_host_to_net_u16(portnum); \
 266               return 0; \
 267             } \
 268         } \
 269       break;
 270       foreach_nat_protocol
 271 #undef _
 272     default:
 273       nat_elog_info ("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   int i;
 290   snat_address_t *a, *ga = 0;
 291   u32 portnum;
 292
 293   for (i = 0; i < vec_len (addresses); i++)
 294     {
 295       a = addresses + i;
 296       switch (proto)
 297         {
 298 #define _(N, j, n, s)                                                         \
 299   case NAT_PROTOCOL_##N:                                                      \
 300     if (a->busy_##n##_ports_per_thread[thread_index] < port_per_thread)       \
 301       {                                                                       \
 302         if (a->fib_index == fib_index)                                        \
 303           {                                                                   \
 304             while (1)                                                         \
 305               {                                                               \
 306                 portnum = (port_per_thread * snat_thread_index) +             \
 307                           snat_random_port (0, port_per_thread - 1) + 1024;   \
 308                 if (a->busy_##n##_port_refcounts[portnum])                    \
 309                   continue;                                                   \
 310                 --a->busy_##n##_port_refcounts[portnum];                      \
 311                 a->busy_##n##_ports_per_thread[thread_index]++;               \
 312                 a->busy_##n##_ports++;                                        \
 313                 *addr = a->addr;                                              \
 314                 *port = clib_host_to_net_u16 (portnum);                       \
 315                 return 0;                                                     \
 316               }                                                               \
 317           }                                                                   \
 318         else if (a->fib_index == ~0)                                          \
 319           {                                                                   \
 320             ga = a;                                                           \
 321           }                                                                   \
 322       }                                                                       \
 323     break;
 324           foreach_nat_protocol
 325 #undef _
 326             default : nat_elog_info ("unknown protocol");
 327           return 1;
 328         }
 329     }
 330
 331   if (ga)
 332     {
 333       a = ga;
 334       switch (proto)
 335         {
 336 #define _(N, j, n, s)                                                         \
 337   case NAT_PROTOCOL_##N:                                                      \
 338     while (1)                                                                 \
 339       {                                                                       \
 340         portnum = (port_per_thread * snat_thread_index) +                     \
 341                   snat_random_port (0, port_per_thread - 1) + 1024;           \
 342         if (a->busy_##n##_port_refcounts[portnum])                            \
 343           continue;                                                           \
 344         ++a->busy_##n##_port_refcounts[portnum];                              \
 345         a->busy_##n##_ports_per_thread[thread_index]++;                       \
 346         a->busy_##n##_ports++;                                                \
 347         *addr = a->addr;                                                      \
 348         *port = clib_host_to_net_u16 (portnum);                               \
 349         return 0;                                                             \
 350       }
 351           break;
 352           foreach_nat_protocol
 353 #undef _
 354             default : nat_elog_info ("unknown protocol");
 355           return 1;
 356         }
 357     }
 358
 359   /* Totally out of translations to use... */
 360   nat_ipfix_logging_addresses_exhausted (thread_index, 0);
 361   return 1;
 362 }
 363
 364 static snat_session_t *
 365 create_session_for_static_mapping_ed (
 366   snat_main_t *sm, vlib_buffer_t *b, ip4_address_t i2o_addr, u16 i2o_port,
 367   u32 i2o_fib_index, ip4_address_t o2i_addr, u16 o2i_port, u32 o2i_fib_index,
 368   nat_protocol_t nat_proto, vlib_node_runtime_t *node, u32 rx_fib_index,
 369   u32 thread_index, twice_nat_type_t twice_nat, lb_nat_type_t lb_nat, f64 now,
 370   snat_static_mapping_t *mapping)
 371 {
 372   snat_session_t *s;
 373   ip4_header_t *ip;
 374   udp_header_t *udp;
 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 ("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_USER_SESS_EXCEEDED];
 389       nat_elog_warn ("create NAT session failed");
 390       return 0;
 391     }
 392
 393   ip = vlib_buffer_get_current (b);
 394   udp = ip4_next_header (ip);
 395
 396   s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 397   s->ext_host_port = nat_proto == NAT_PROTOCOL_ICMP ? 0 : udp->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 ("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 ("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 ("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 ("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 (s->user_index, s->in2out.fib_index,
 561                          &s->in2out.addr, s->in2out.port,
 562                          &s->ext_host_nat_addr, s->ext_host_nat_port,
 563                          &s->out2in.addr, s->out2in.port,
 564                          &s->ext_host_addr, s->ext_host_port,
 565                          s->nat_proto, is_twice_nat_session (s));
 566
 567   per_vrf_sessions_register_session (s, thread_index);
 568
 569   return s;
 570 }
 571
 572 static void
 573 create_bypass_for_fwd (snat_main_t *sm, vlib_buffer_t *b, snat_session_t *s,
 574                        ip4_header_t *ip, u32 rx_fib_index, u32 thread_index)
 575 {
 576   clib_bihash_kv_16_8_t kv, value;
 577   udp_header_t *udp;
 578   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 579   vlib_main_t *vm = vlib_get_main ();
 580   f64 now = vlib_time_now (vm);
 581   u16 lookup_sport, lookup_dport;
 582   u8 lookup_protocol;
 583   ip4_address_t lookup_saddr, lookup_daddr;
 584
 585   if (ip->protocol == IP_PROTOCOL_ICMP)
 586     {
 587       if (nat_get_icmp_session_lookup_values (b, ip, &lookup_saddr,
 588                                               &lookup_sport, &lookup_daddr,
 589                                               &lookup_dport, &lookup_protocol))
 590         return;
 591     }
 592   else
 593     {
 594       if (ip->protocol == IP_PROTOCOL_UDP || ip->protocol == IP_PROTOCOL_TCP)
 595         {
 596           udp = ip4_next_header (ip);
 597           lookup_sport = udp->dst_port;
 598           lookup_dport = udp->src_port;
 599         }
 600       else
 601         {
 602           lookup_sport = 0;
 603           lookup_dport = 0;
 604         }
 605       lookup_saddr.as_u32 = ip->dst_address.as_u32;
 606       lookup_daddr.as_u32 = ip->src_address.as_u32;
 607       lookup_protocol = ip->protocol;
 608     }
 609
 610   init_ed_k (&kv, lookup_saddr, lookup_sport, lookup_daddr, lookup_dport,
 611              rx_fib_index, lookup_protocol);
 612
 613   if (!clib_bihash_search_16_8 (&sm->flow_hash, &kv, &value))
 614     {
 615       ASSERT (thread_index == ed_value_get_thread_index (&value));
 616       s =
 617         pool_elt_at_index (tsm->sessions,
 618                            ed_value_get_session_index (&value));
 619     }
 620   else if (ip->protocol == IP_PROTOCOL_ICMP &&
 621            icmp_type_is_error_message
 622            (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags))
 623     {
 624       return;
 625     }
 626   else
 627     {
 628       u32 proto;
 629
 630       if (PREDICT_FALSE
 631           (nat44_ed_maximum_sessions_exceeded
 632            (sm, rx_fib_index, thread_index)))
 633         return;
 634
 635       s = nat_ed_session_alloc (sm, thread_index, now, ip->protocol);
 636       if (!s)
 637         {
 638           nat_elog_warn ("create NAT session failed");
 639           return;
 640         }
 641
 642       proto = ip_proto_to_nat_proto (ip->protocol);
 643
 644       s->ext_host_addr = ip->src_address;
 645       s->ext_host_port = lookup_dport;
 646       s->flags |= SNAT_SESSION_FLAG_FWD_BYPASS;
 647       s->out2in.addr = ip->dst_address;
 648       s->out2in.port = lookup_sport;
 649       s->nat_proto = proto;
 650       if (proto == NAT_PROTOCOL_OTHER)
 651         {
 652           s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 653           s->out2in.port = ip->protocol;
 654         }
 655       s->out2in.fib_index = rx_fib_index;
 656       s->in2out.addr = s->out2in.addr;
 657       s->in2out.port = s->out2in.port;
 658       s->in2out.fib_index = s->out2in.fib_index;
 659
 660       nat_6t_i2o_flow_init (sm, thread_index, s, ip->dst_address, lookup_sport,
 661                             ip->src_address, lookup_dport, rx_fib_index,
 662                             ip->protocol);
 663       nat_6t_flow_txfib_rewrite_set (&s->i2o, rx_fib_index);
 664       if (nat_ed_ses_i2o_flow_hash_add_del (sm, thread_index, s, 1))
 665         {
 666           nat_elog_notice ("in2out flow add failed");
 667           nat_ed_session_delete (sm, s, thread_index, 1);
 668           return;
 669         }
 670
 671       per_vrf_sessions_register_session (s, thread_index);
 672     }
 673
 674   if (ip->protocol == IP_PROTOCOL_TCP)
 675     {
 676       tcp_header_t *tcp = ip4_next_header (ip);
 677       nat44_set_tcp_session_state_o2i (sm, now, s, tcp->flags,
 678                                        tcp->ack_number, tcp->seq_number,
 679                                        thread_index);
 680     }
 681
 682   /* Accounting */
 683   nat44_session_update_counters (s, now, 0, thread_index);
 684   /* Per-user LRU list maintenance */
 685   nat44_session_update_lru (sm, s, thread_index);
 686 }
 687
 688 static snat_session_t *
 689 nat44_ed_out2in_slowpath_unknown_proto (snat_main_t *sm, vlib_buffer_t *b,
 690                                         ip4_header_t *ip, u32 rx_fib_index,
 691                                         u32 thread_index, f64 now,
 692                                         vlib_main_t *vm,
 693                                         vlib_node_runtime_t *node)
 694 {
 695   clib_bihash_kv_8_8_t kv, value;
 696   snat_static_mapping_t *m;
 697   snat_session_t *s;
 698
 699   if (PREDICT_FALSE (
 700         nat44_ed_maximum_sessions_exceeded (sm, rx_fib_index, thread_index)))
 701     {
 702       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 703       nat_elog_notice ("maximum sessions exceeded");
 704       return 0;
 705     }
 706
 707   init_nat_k (&kv, ip->dst_address, 0, 0, 0);
 708   if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
 709     {
 710       b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 711       return 0;
 712     }
 713
 714   m = pool_elt_at_index (sm->static_mappings, value.value);
 715
 716   /* Create a new session */
 717   s = nat_ed_session_alloc (sm, thread_index, now, ip->protocol);
 718   if (!s)
 719     {
 720       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_USER_SESS_EXCEEDED];
 721       nat_elog_warn ("create NAT session failed");
 722       return 0;
 723     }
 724
 725   s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 726   s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 727   s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 728   s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 729   s->out2in.addr.as_u32 = ip->dst_address.as_u32;
 730   s->out2in.fib_index = rx_fib_index;
 731   s->in2out.addr.as_u32 = m->local_addr.as_u32;
 732   s->in2out.fib_index = m->fib_index;
 733   s->in2out.port = s->out2in.port = ip->protocol;
 734
 735   nat_6t_o2i_flow_init (sm, thread_index, s, ip->dst_address, 0,
 736                         ip->src_address, 0, m->fib_index, ip->protocol);
 737   nat_6t_flow_saddr_rewrite_set (&s->i2o, ip->dst_address.as_u32);
 738   if (nat_ed_ses_i2o_flow_hash_add_del (sm, thread_index, s, 1))
 739     {
 740       nat_elog_notice ("in2out key add failed");
 741       nat_ed_session_delete (sm, s, thread_index, 1);
 742       return NULL;
 743     }
 744
 745   nat_6t_o2i_flow_init (sm, thread_index, s, ip->src_address, 0,
 746                         ip->dst_address, 0, rx_fib_index, ip->protocol);
 747   nat_6t_flow_daddr_rewrite_set (&s->o2i, m->local_addr.as_u32);
 748   nat_6t_flow_txfib_rewrite_set (&s->o2i, m->fib_index);
 749   if (nat_ed_ses_o2i_flow_hash_add_del (sm, thread_index, s, 1))
 750     {
 751       nat_elog_notice ("out2in flow hash add failed");
 752       nat_ed_session_delete (sm, s, thread_index, 1);
 753       return NULL;
 754     }
 755
 756   per_vrf_sessions_register_session (s, thread_index);
 757
 758   /* Accounting */
 759   nat44_session_update_counters (s, now, vlib_buffer_length_in_chain (vm, b),
 760                                  thread_index);
 761   /* Per-user LRU list maintenance */
 762   nat44_session_update_lru (sm, s, thread_index);
 763
 764   return s;
 765 }
 766
 767 static inline uword
 768 nat44_ed_out2in_fast_path_node_fn_inline (vlib_main_t * vm,
 769                                           vlib_node_runtime_t * node,
 770                                           vlib_frame_t * frame,
 771                                           int is_multi_worker)
 772 {
 773   u32 n_left_from, *from;
 774   snat_main_t *sm = &snat_main;
 775   f64 now = vlib_time_now (vm);
 776   u32 thread_index = vm->thread_index;
 777   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 778
 779   from = vlib_frame_vector_args (frame);
 780   n_left_from = frame->n_vectors;
 781
 782   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b = bufs;
 783   u16 nexts[VLIB_FRAME_SIZE], *next = nexts;
 784   vlib_get_buffers (vm, from, b, n_left_from);
 785
 786   while (n_left_from > 0)
 787     {
 788       vlib_buffer_t *b0;
 789       u32 sw_if_index0, rx_fib_index0;
 790       nat_protocol_t proto0;
 791       ip4_header_t *ip0;
 792       snat_session_t *s0 = 0;
 793       clib_bihash_kv_16_8_t kv0, value0;
 794       nat_translation_error_e translation_error = NAT_ED_TRNSL_ERR_SUCCESS;
 795       nat_6t_flow_t *f = 0;
 796       ip4_address_t lookup_saddr, lookup_daddr;
 797       u16 lookup_sport, lookup_dport;
 798       u8 lookup_protocol;
 799       int lookup_skipped = 0;
 800
 801       b0 = *b;
 802       b++;
 803
 804       lookup_sport = vnet_buffer (b0)->ip.reass.l4_src_port;
 805       lookup_dport = vnet_buffer (b0)->ip.reass.l4_dst_port;
 806
 807       /* Prefetch next iteration. */
 808       if (PREDICT_TRUE (n_left_from >= 2))
 809         {
 810           vlib_buffer_t *p2;
 811
 812           p2 = *b;
 813
 814           vlib_prefetch_buffer_header (p2, LOAD);
 815
 816           CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, LOAD);
 817         }
 818
 819       next[0] = vnet_buffer2 (b0)->nat.arc_next;
 820
 821       vnet_buffer (b0)->snat.flags = 0;
 822       ip0 = vlib_buffer_get_current (b0);
 823
 824       sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 825       rx_fib_index0 =
 826         fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4, sw_if_index0);
 827
 828       if (PREDICT_FALSE (ip0->ttl == 1))
 829         {
 830           vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 831           icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 832                                        ICMP4_time_exceeded_ttl_exceeded_in_transit,
 833                                        0);
 834           next[0] = NAT_NEXT_ICMP_ERROR;
 835           goto trace0;
 836         }
 837
 838       proto0 = ip_proto_to_nat_proto (ip0->protocol);
 839
 840       if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
 841         {
 842           if (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
 843                 ICMP4_echo_request &&
 844               vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
 845                 ICMP4_echo_reply &&
 846               !icmp_type_is_error_message (
 847                 vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags))
 848             {
 849               b0->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 850               next[0] = NAT_NEXT_DROP;
 851               goto trace0;
 852             }
 853           int err = nat_get_icmp_session_lookup_values (
 854             b0, ip0, &lookup_saddr, &lookup_sport, &lookup_daddr,
 855             &lookup_dport, &lookup_protocol);
 856           if (err != 0)
 857             {
 858               b0->error = node->errors[err];
 859               next[0] = NAT_NEXT_DROP;
 860               goto trace0;
 861             }
 862         }
 863       else
 864         {
 865           lookup_saddr.as_u32 = ip0->src_address.as_u32;
 866           lookup_daddr.as_u32 = ip0->dst_address.as_u32;
 867           lookup_protocol = ip0->protocol;
 868         }
 869
 870       /* there might be a stashed index in vnet_buffer2 from handoff or
 871        * classify node, see if it can be used */
 872       if (!pool_is_free_index (tsm->sessions,
 873                                vnet_buffer2 (b0)->nat.cached_session_index))
 874         {
 875           s0 = pool_elt_at_index (tsm->sessions,
 876                                   vnet_buffer2 (b0)->nat.cached_session_index);
 877           if (PREDICT_TRUE (
 878                 nat_6t_flow_match (&s0->o2i, b0, lookup_saddr, lookup_sport,
 879                                    lookup_daddr, lookup_dport, lookup_protocol,
 880                                    rx_fib_index0) ||
 881                 (s0->flags & SNAT_SESSION_FLAG_TWICE_NAT &&
 882                  nat_6t_flow_match (&s0->i2o, b0, lookup_saddr, lookup_sport,
 883                                     lookup_daddr, lookup_dport,
 884                                     lookup_protocol, rx_fib_index0))))
 885             {
 886               /* yes, this is the droid we're looking for */
 887               lookup_skipped = 1;
 888               goto skip_lookup;
 889             }
 890           s0 = NULL;
 891         }
 892
 893       init_ed_k (&kv0, lookup_saddr, lookup_sport, lookup_daddr, lookup_dport,
 894                  rx_fib_index0, lookup_protocol);
 895
 896       // lookup flow
 897       if (clib_bihash_search_16_8 (&sm->flow_hash, &kv0, &value0))
 898         {
 899           // flow does not exist go slow path
 900           next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 901           goto trace0;
 902         }
 903       ASSERT (thread_index == ed_value_get_thread_index (&value0));
 904       s0 =
 905         pool_elt_at_index (tsm->sessions,
 906                            ed_value_get_session_index (&value0));
 907     skip_lookup:
 908
 909       if (PREDICT_FALSE (per_vrf_sessions_is_expired (s0, thread_index)))
 910         {
 911           // session is closed, go slow path
 912           nat_free_session_data (sm, s0, thread_index, 0);
 913           nat_ed_session_delete (sm, s0, thread_index, 1);
 914           next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 915           goto trace0;
 916         }
 917
 918       if (s0->tcp_closed_timestamp)
 919         {
 920           if (now >= s0->tcp_closed_timestamp)
 921             {
 922               // session is closed, go slow path, freed in slow path
 923               next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 924             }
 925           else
 926             {
 927               // session in transitory timeout, drop
 928               b0->error = node->errors[NAT_OUT2IN_ED_ERROR_TCP_CLOSED];
 929               next[0] = NAT_NEXT_DROP;
 930             }
 931           goto trace0;
 932         }
 933
 934       // drop if session expired
 935       u64 sess_timeout_time;
 936       sess_timeout_time =
 937         s0->last_heard + (f64) nat44_session_get_timeout (sm, s0);
 938       if (now >= sess_timeout_time)
 939         {
 940           // session is closed, go slow path
 941           nat_free_session_data (sm, s0, thread_index, 0);
 942           nat_ed_session_delete (sm, s0, thread_index, 1);
 943           next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 944           goto trace0;
 945         }
 946
 947       if (nat_6t_flow_match (&s0->o2i, b0, lookup_saddr, lookup_sport,
 948                              lookup_daddr, lookup_dport, lookup_protocol,
 949                              rx_fib_index0))
 950         {
 951           f = &s0->o2i;
 952         }
 953       else if (s0->flags & SNAT_SESSION_FLAG_TWICE_NAT &&
 954                nat_6t_flow_match (&s0->i2o, b0, lookup_saddr, lookup_sport,
 955                                   lookup_daddr, lookup_dport, lookup_protocol,
 956                                   rx_fib_index0))
 957         {
 958           f = &s0->i2o;
 959         }
 960       else
 961         {
 962           /*
 963            * Send DHCP packets to the ipv4 stack, or we won't
 964            * be able to use dhcp client on the outside interface
 965            */
 966           if (PREDICT_FALSE (
 967                 proto0 == NAT_PROTOCOL_UDP &&
 968                 (vnet_buffer (b0)->ip.reass.l4_dst_port ==
 969                  clib_host_to_net_u16 (UDP_DST_PORT_dhcp_to_client))))
 970             {
 971               goto trace0;
 972             }
 973
 974           if (!sm->forwarding_enabled)
 975             {
 976               b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 977               next[0] = NAT_NEXT_DROP;
 978               goto trace0;
 979             }
 980           else
 981             {
 982               if (nat_6t_flow_match (&s0->i2o, b0, lookup_saddr, lookup_sport,
 983                                      lookup_daddr, lookup_dport,
 984                                      lookup_protocol, rx_fib_index0))
 985                 {
 986                   f = &s0->i2o;
 987                 }
 988               else
 989                 {
 990                   // FIXME TODO bypass ???
 991                   //  create_bypass_for_fwd (sm, b0, s0, ip0, rx_fib_index0,
 992                   //                       thread_index);
 993                   translation_error = NAT_ED_TRNSL_ERR_FLOW_MISMATCH;
 994                   nat_free_session_data (sm, s0, thread_index, 0);
 995                   nat_ed_session_delete (sm, s0, thread_index, 1);
 996                   next[0] = NAT_NEXT_DROP;
 997                   goto trace0;
 998                 }
 999             }
1000         }
1001
1002       if (NAT_ED_TRNSL_ERR_SUCCESS !=
1003           (translation_error = nat_6t_flow_buf_translate (
1004              sm, b0, ip0, f, proto0, 0 /* is_output_feature */)))
1005         {
1006           next[0] = NAT_NEXT_DROP;
1007           goto trace0;
1008         }
1009
1010       switch (proto0)
1011         {
1012         case NAT_PROTOCOL_TCP:
1013           vlib_increment_simple_counter (&sm->counters.fastpath.out2in_ed.tcp,
1014                                          thread_index, sw_if_index0, 1);
1015           nat44_set_tcp_session_state_o2i (sm, now, s0,
1016                                            vnet_buffer (b0)->ip.
1017                                            reass.icmp_type_or_tcp_flags,
1018                                            vnet_buffer (b0)->ip.
1019                                            reass.tcp_ack_number,
1020                                            vnet_buffer (b0)->ip.
1021                                            reass.tcp_seq_number,
1022                                            thread_index);
1023           break;
1024         case NAT_PROTOCOL_UDP:
1025           vlib_increment_simple_counter (&sm->counters.fastpath.out2in_ed.udp,
1026                                          thread_index, sw_if_index0, 1);
1027           break;
1028         case NAT_PROTOCOL_ICMP:
1029           vlib_increment_simple_counter (&sm->counters.fastpath.out2in_ed.icmp,
1030                                          thread_index, sw_if_index0, 1);
1031           break;
1032         case NAT_PROTOCOL_OTHER:
1033           vlib_increment_simple_counter (
1034             &sm->counters.fastpath.out2in_ed.other, thread_index, sw_if_index0,
1035             1);
1036           break;
1037         }
1038
1039       /* Accounting */
1040       nat44_session_update_counters (s0, now,
1041                                      vlib_buffer_length_in_chain (vm, b0),
1042                                      thread_index);
1043       /* Per-user LRU list maintenance */
1044       nat44_session_update_lru (sm, s0, thread_index);
1045
1046     trace0:
1047       if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1048                          && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1049         {
1050           nat44_ed_out2in_trace_t *t =
1051             vlib_add_trace (vm, node, b0, sizeof (*t));
1052           t->sw_if_index = sw_if_index0;
1053           t->next_index = next[0];
1054           t->is_slow_path = 0;
1055           t->translation_error = translation_error;
1056           clib_memcpy (&t->search_key, &kv0, sizeof (t->search_key));
1057           t->lookup_skipped = lookup_skipped;
1058
1059           if (s0)
1060             {
1061               t->session_index = s0 - tsm->sessions;
1062               clib_memcpy (&t->i2of, &s0->i2o, sizeof (t->i2of));
1063               clib_memcpy (&t->o2if, &s0->o2i, sizeof (t->o2if));
1064               t->translation_via_i2of = (&s0->i2o == f);
1065             }
1066           else
1067             {
1068               t->session_index = ~0;
1069             }
1070         }
1071
1072       if (next[0] == NAT_NEXT_DROP)
1073         {
1074           vlib_increment_simple_counter (&sm->counters.fastpath.
1075                                          out2in_ed.drops, thread_index,
1076                                          sw_if_index0, 1);
1077         }
1078
1079       n_left_from--;
1080       next++;
1081     }
1082
1083   vlib_buffer_enqueue_to_next (vm, node, from, (u16 *) nexts,
1084                                frame->n_vectors);
1085   return frame->n_vectors;
1086 }
1087
1088 static inline uword
1089 nat44_ed_out2in_slow_path_node_fn_inline (vlib_main_t * vm,
1090                                           vlib_node_runtime_t * node,
1091                                           vlib_frame_t * frame)
1092 {
1093   u32 n_left_from, *from;
1094   snat_main_t *sm = &snat_main;
1095   f64 now = vlib_time_now (vm);
1096   u32 thread_index = vm->thread_index;
1097   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
1098   snat_static_mapping_t *m;
1099
1100   from = vlib_frame_vector_args (frame);
1101   n_left_from = frame->n_vectors;
1102
1103   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b = bufs;
1104   u16 nexts[VLIB_FRAME_SIZE], *next = nexts;
1105   vlib_get_buffers (vm, from, b, n_left_from);
1106
1107   while (n_left_from > 0)
1108     {
1109       vlib_buffer_t *b0;
1110       u32 sw_if_index0, rx_fib_index0;
1111       nat_protocol_t proto0;
1112       ip4_header_t *ip0;
1113       udp_header_t *udp0;
1114       icmp46_header_t *icmp0;
1115       snat_session_t *s0 = 0;
1116       clib_bihash_kv_16_8_t kv0, value0;
1117       lb_nat_type_t lb_nat0;
1118       twice_nat_type_t twice_nat0;
1119       u8 identity_nat0;
1120       ip4_address_t sm_addr;
1121       u16 sm_port;
1122       u32 sm_fib_index;
1123       nat_translation_error_e translation_error = NAT_ED_TRNSL_ERR_SUCCESS;
1124
1125       b0 = *b;
1126       next[0] = vnet_buffer2 (b0)->nat.arc_next;
1127
1128       vnet_buffer (b0)->snat.flags = 0;
1129       ip0 = vlib_buffer_get_current (b0);
1130
1131       sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1132       rx_fib_index0 =
1133         fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4, sw_if_index0);
1134
1135       if (PREDICT_FALSE (ip0->ttl == 1))
1136         {
1137           vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1138           icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1139                                        ICMP4_time_exceeded_ttl_exceeded_in_transit,
1140                                        0);
1141           next[0] = NAT_NEXT_ICMP_ERROR;
1142           goto trace0;
1143         }
1144
1145       udp0 = ip4_next_header (ip0);
1146       icmp0 = (icmp46_header_t *) udp0;
1147       proto0 = ip_proto_to_nat_proto (ip0->protocol);
1148
1149       if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
1150         {
1151           s0 = nat44_ed_out2in_slowpath_unknown_proto (
1152             sm, b0, ip0, rx_fib_index0, thread_index, now, vm, node);
1153           if (!sm->forwarding_enabled)
1154             {
1155               if (!s0)
1156                 next[0] = NAT_NEXT_DROP;
1157             }
1158           if (NAT_NEXT_DROP != next[0] &&
1159               NAT_ED_TRNSL_ERR_SUCCESS !=
1160                 (translation_error = nat_6t_flow_buf_translate (
1161                    sm, b0, ip0, &s0->o2i, proto0, 0 /* is_output_feature */)))
1162             {
1163               goto trace0;
1164             }
1165
1166           vlib_increment_simple_counter (&sm->counters.slowpath.
1167                                          out2in_ed.other, thread_index,
1168                                          sw_if_index0, 1);
1169           goto trace0;
1170         }
1171
1172       if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
1173         {
1174           next[0] = icmp_out2in_ed_slow_path
1175             (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1176              next[0], now, thread_index, &s0);
1177
1178           if (NAT_NEXT_DROP != next[0] && s0 &&
1179               NAT_ED_TRNSL_ERR_SUCCESS !=
1180                 (translation_error = nat_6t_flow_buf_translate (
1181                    sm, b0, ip0, &s0->o2i, proto0, 0 /* is_output_feature */)))
1182             {
1183               goto trace0;
1184             }
1185
1186           vlib_increment_simple_counter (&sm->counters.slowpath.
1187                                          out2in_ed.icmp, thread_index,
1188                                          sw_if_index0, 1);
1189           goto trace0;
1190         }
1191
1192       init_ed_k (&kv0, ip0->src_address,
1193                  vnet_buffer (b0)->ip.reass.l4_src_port, ip0->dst_address,
1194                  vnet_buffer (b0)->ip.reass.l4_dst_port, rx_fib_index0,
1195                  ip0->protocol);
1196
1197       s0 = NULL;
1198       if (!clib_bihash_search_16_8 (&sm->flow_hash, &kv0, &value0))
1199         {
1200           ASSERT (thread_index == ed_value_get_thread_index (&value0));
1201           s0 =
1202             pool_elt_at_index (tsm->sessions,
1203                                ed_value_get_session_index (&value0));
1204
1205           if (s0->tcp_closed_timestamp && now >= s0->tcp_closed_timestamp)
1206             {
1207               nat_free_session_data (sm, s0, thread_index, 0);
1208               nat_ed_session_delete (sm, s0, thread_index, 1);
1209               s0 = NULL;
1210             }
1211         }
1212
1213       if (!s0)
1214         {
1215           /* Try to match static mapping by external address and port,
1216              destination address and port in packet */
1217
1218           if (snat_static_mapping_match
1219               (sm, ip0->dst_address,
1220                vnet_buffer (b0)->ip.reass.l4_dst_port, rx_fib_index0,
1221                proto0, &sm_addr, &sm_port, &sm_fib_index, 1, 0,
1222                &twice_nat0, &lb_nat0, &ip0->src_address, &identity_nat0, &m))
1223             {
1224               /*
1225                * Send DHCP packets to the ipv4 stack, or we won't
1226                * be able to use dhcp client on the outside interface
1227                */
1228               if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_UDP
1229                                  && (vnet_buffer (b0)->ip.reass.l4_dst_port ==
1230                                      clib_host_to_net_u16
1231                                      (UDP_DST_PORT_dhcp_to_client))))
1232                 {
1233                   goto trace0;
1234                 }
1235
1236               if (!sm->forwarding_enabled)
1237                 {
1238                   b0->error =
1239                     node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
1240                   next[0] = NAT_NEXT_DROP;
1241                 }
1242               else
1243                 {
1244                   if (next_src_nat
1245                       (sm, ip0, vnet_buffer (b0)->ip.reass.l4_src_port,
1246                        vnet_buffer (b0)->ip.reass.l4_dst_port,
1247                        thread_index, rx_fib_index0))
1248                     {
1249                       next[0] = NAT_NEXT_IN2OUT_ED_FAST_PATH;
1250                     }
1251                   else
1252                     {
1253                       create_bypass_for_fwd (sm, b0, s0, ip0, rx_fib_index0,
1254                                              thread_index);
1255                     }
1256                 }
1257               goto trace0;
1258             }
1259
1260           if (PREDICT_FALSE (identity_nat0))
1261             goto trace0;
1262
1263           if ((proto0 == NAT_PROTOCOL_TCP)
1264               && !tcp_flags_is_init (vnet_buffer (b0)->ip.
1265                                      reass.icmp_type_or_tcp_flags))
1266             {
1267               b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
1268               next[0] = NAT_NEXT_DROP;
1269               goto trace0;
1270             }
1271
1272           /* Create session initiated by host from external network */
1273           s0 = create_session_for_static_mapping_ed (sm, b0,
1274                                                      sm_addr, sm_port,
1275                                                      sm_fib_index,
1276                                                      ip0->dst_address,
1277                                                      vnet_buffer (b0)->
1278                                                      ip.reass.l4_dst_port,
1279                                                      rx_fib_index0, proto0,
1280                                                      node, rx_fib_index0,
1281                                                      thread_index, twice_nat0,
1282                                                      lb_nat0, now, m);
1283           if (!s0)
1284             {
1285               next[0] = NAT_NEXT_DROP;
1286               goto trace0;
1287             }
1288         }
1289
1290       if (NAT_ED_TRNSL_ERR_SUCCESS !=
1291           (translation_error = nat_6t_flow_buf_translate (
1292              sm, b0, ip0, &s0->o2i, proto0, 0 /* is_output_feature */)))
1293         {
1294           next[0] = NAT_NEXT_DROP;
1295           goto trace0;
1296         }
1297
1298       if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
1299         {
1300           vlib_increment_simple_counter (&sm->counters.slowpath.out2in_ed.tcp,
1301                                          thread_index, sw_if_index0, 1);
1302           nat44_set_tcp_session_state_o2i (sm, now, s0,
1303                                            vnet_buffer (b0)->ip.
1304                                            reass.icmp_type_or_tcp_flags,
1305                                            vnet_buffer (b0)->ip.
1306                                            reass.tcp_ack_number,
1307                                            vnet_buffer (b0)->ip.
1308                                            reass.tcp_seq_number,
1309                                            thread_index);
1310         }
1311       else
1312         {
1313           vlib_increment_simple_counter (&sm->counters.slowpath.out2in_ed.udp,
1314                                          thread_index, sw_if_index0, 1);
1315         }
1316
1317       /* Accounting */
1318       nat44_session_update_counters (s0, now,
1319                                      vlib_buffer_length_in_chain (vm, b0),
1320                                      thread_index);
1321       /* Per-user LRU list maintenance */
1322       nat44_session_update_lru (sm, s0, thread_index);
1323
1324     trace0:
1325       if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1326                          && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1327         {
1328           nat44_ed_out2in_trace_t *t =
1329             vlib_add_trace (vm, node, b0, sizeof (*t));
1330           t->sw_if_index = sw_if_index0;
1331           t->next_index = next[0];
1332           t->is_slow_path = 1;
1333           t->translation_error = translation_error;
1334           clib_memcpy (&t->search_key, &kv0, sizeof (t->search_key));
1335
1336           if (s0)
1337             {
1338               t->session_index = s0 - tsm->sessions;
1339               clib_memcpy (&t->i2of, &s0->i2o, sizeof (t->i2of));
1340               clib_memcpy (&t->o2if, &s0->o2i, sizeof (t->o2if));
1341             }
1342           else
1343             {
1344               t->session_index = ~0;
1345             }
1346         }
1347
1348       if (next[0] == NAT_NEXT_DROP)
1349         {
1350           vlib_increment_simple_counter (&sm->counters.slowpath.
1351                                          out2in_ed.drops, thread_index,
1352                                          sw_if_index0, 1);
1353         }
1354
1355       n_left_from--;
1356       next++;
1357       b++;
1358     }
1359
1360   vlib_buffer_enqueue_to_next (vm, node, from, (u16 *) nexts,
1361                                frame->n_vectors);
1362
1363   return frame->n_vectors;
1364 }
1365
1366 VLIB_NODE_FN (nat44_ed_out2in_node) (vlib_main_t * vm,
1367                                      vlib_node_runtime_t * node,
1368                                      vlib_frame_t * frame)
1369 {
1370   if (snat_main.num_workers > 1)
1371     {
1372       return nat44_ed_out2in_fast_path_node_fn_inline (vm, node, frame, 1);
1373     }
1374   else
1375     {
1376       return nat44_ed_out2in_fast_path_node_fn_inline (vm, node, frame, 0);
1377     }
1378 }
1379
1380 /* *INDENT-OFF* */
1381 VLIB_REGISTER_NODE (nat44_ed_out2in_node) = {
1382   .name = "nat44-ed-out2in",
1383   .vector_size = sizeof (u32),
1384   .sibling_of = "nat-default",
1385   .format_trace = format_nat44_ed_out2in_trace,
1386   .type = VLIB_NODE_TYPE_INTERNAL,
1387   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1388   .error_strings = nat_out2in_ed_error_strings,
1389   .runtime_data_bytes = sizeof (snat_runtime_t),
1390 };
1391 /* *INDENT-ON* */
1392
1393 VLIB_NODE_FN (nat44_ed_out2in_slowpath_node) (vlib_main_t * vm,
1394                                               vlib_node_runtime_t * node,
1395                                               vlib_frame_t * frame)
1396 {
1397   return nat44_ed_out2in_slow_path_node_fn_inline (vm, node, frame);
1398 }
1399
1400 /* *INDENT-OFF* */
1401 VLIB_REGISTER_NODE (nat44_ed_out2in_slowpath_node) = {
1402   .name = "nat44-ed-out2in-slowpath",
1403   .vector_size = sizeof (u32),
1404   .sibling_of = "nat-default",
1405   .format_trace = format_nat44_ed_out2in_trace,
1406   .type = VLIB_NODE_TYPE_INTERNAL,
1407   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1408   .error_strings = nat_out2in_ed_error_strings,
1409   .runtime_data_bytes = sizeof (snat_runtime_t),
1410 };
1411 /* *INDENT-ON* */
1412
1413 static u8 *
1414 format_nat_pre_trace (u8 * s, va_list * args)
1415 {
1416   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1417   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1418   nat_pre_trace_t *t = va_arg (*args, nat_pre_trace_t *);
1419   return format (s, "out2in next_index %d arc_next_index %d", t->next_index,
1420                  t->arc_next_index);
1421 }
1422
1423 VLIB_NODE_FN (nat_pre_out2in_node) (vlib_main_t * vm,
1424                                     vlib_node_runtime_t * node,
1425                                     vlib_frame_t * frame)
1426 {
1427   return nat_pre_node_fn_inline (vm, node, frame,
1428                                  NAT_NEXT_OUT2IN_ED_FAST_PATH);
1429 }
1430
1431 /* *INDENT-OFF* */
1432 VLIB_REGISTER_NODE (nat_pre_out2in_node) = {
1433   .name = "nat-pre-out2in",
1434   .vector_size = sizeof (u32),
1435   .sibling_of = "nat-default",
1436   .format_trace = format_nat_pre_trace,
1437   .type = VLIB_NODE_TYPE_INTERNAL,
1438   .n_errors = 0,
1439  };
1440 /* *INDENT-ON* */
1441
1442 /*
1443  * fd.io coding-style-patch-verification: ON
1444  *
1445  * Local Variables:
1446  * eval: (c-set-style "gnu")
1447  * End:
1448  */