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/pg/pg.h>
  23 #include <vnet/ip/ip.h>
  24 #include <vnet/ethernet/ethernet.h>
  25 #include <vnet/fib/ip4_fib.h>
  26 #include <vnet/udp/udp.h>
  27 #include <vppinfra/error.h>
  28 #include <nat/nat.h>
  29 #include <nat/nat_ipfix_logging.h>
  30 #include <nat/nat_inlines.h>
  31 #include <nat/nat44/inlines.h>
  32 #include <nat/nat_syslog.h>
  33 #include <nat/nat_ha.h>
  34
  35 static char *nat_out2in_ed_error_strings[] = {
  36 #define _(sym,string) string,
  37   foreach_nat_out2in_ed_error
  38 #undef _
  39 };
  40
  41 typedef struct
  42 {
  43   u32 sw_if_index;
  44   u32 next_index;
  45   u32 session_index;
  46   u32 is_slow_path;
  47 } nat44_ed_out2in_trace_t;
  48
  49 static u8 *
  50 format_nat44_ed_out2in_trace (u8 * s, va_list * args)
  51 {
  52   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  53   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  54   nat44_ed_out2in_trace_t *t = va_arg (*args, nat44_ed_out2in_trace_t *);
  55   char *tag;
  56
  57   tag =
  58     t->is_slow_path ? "NAT44_OUT2IN_ED_SLOW_PATH" :
  59     "NAT44_OUT2IN_ED_FAST_PATH";
  60
  61   s = format (s, "%s: sw_if_index %d, next index %d, session %d", tag,
  62               t->sw_if_index, t->next_index, t->session_index);
  63
  64   return s;
  65 }
  66
  67 static inline u32
  68 icmp_out2in_ed_slow_path (snat_main_t * sm, vlib_buffer_t * b0,
  69                           ip4_header_t * ip0, icmp46_header_t * icmp0,
  70                           u32 sw_if_index0, u32 rx_fib_index0,
  71                           vlib_node_runtime_t * node, u32 next0, f64 now,
  72                           u32 thread_index, snat_session_t ** p_s0)
  73 {
  74   next0 = icmp_out2in (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
  75                        next0, thread_index, p_s0, 0);
  76   snat_session_t *s0 = *p_s0;
  77   if (PREDICT_TRUE (next0 != NAT_NEXT_DROP && s0))
  78     {
  79       /* Accounting */
  80       nat44_session_update_counters (s0, now,
  81                                      vlib_buffer_length_in_chain
  82                                      (sm->vlib_main, b0), thread_index);
  83       /* Per-user LRU list maintenance */
  84       nat44_session_update_lru (sm, s0, thread_index);
  85     }
  86   return next0;
  87 }
  88
  89 #ifndef CLIB_MARCH_VARIANT
  90 int
  91 nat44_o2i_ed_is_idle_session_cb (clib_bihash_kv_16_8_t * kv, void *arg)
  92 {
  93   snat_main_t *sm = &snat_main;
  94   nat44_is_idle_session_ctx_t *ctx = arg;
  95   snat_session_t *s;
  96   u64 sess_timeout_time;
  97   nat_ed_ses_key_t ed_key;
  98   clib_bihash_kv_16_8_t ed_kv;
  99   int i;
 100   snat_address_t *a;
 101   snat_session_key_t key;
 102   snat_main_per_thread_data_t *tsm = vec_elt_at_index (sm->per_thread_data,
 103                                                        ctx->thread_index);
 104
 105   s = pool_elt_at_index (tsm->sessions, kv->value);
 106   sess_timeout_time = s->last_heard + (f64) nat44_session_get_timeout (sm, s);
 107   if (ctx->now >= sess_timeout_time)
 108     {
 109       ed_key.l_addr = s->in2out.addr;
 110       ed_key.r_addr = s->ext_host_addr;
 111       ed_key.fib_index = s->in2out.fib_index;
 112       if (snat_is_unk_proto_session (s))
 113         {
 114           ed_key.proto = s->in2out.port;
 115           ed_key.r_port = 0;
 116           ed_key.l_port = 0;
 117         }
 118       else
 119         {
 120           ed_key.proto = snat_proto_to_ip_proto (s->in2out.protocol);
 121           ed_key.l_port = s->in2out.port;
 122           ed_key.r_port = s->ext_host_port;
 123         }
 124       if (is_twice_nat_session (s))
 125         {
 126           ed_key.r_addr = s->ext_host_nat_addr;
 127           ed_key.r_port = s->ext_host_nat_port;
 128         }
 129       ed_kv.key[0] = ed_key.as_u64[0];
 130       ed_kv.key[1] = ed_key.as_u64[1];
 131       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &ed_kv, 0))
 132         nat_elog_warn ("in2out_ed key del failed");
 133
 134       if (snat_is_unk_proto_session (s))
 135         goto delete;
 136
 137       snat_ipfix_logging_nat44_ses_delete (ctx->thread_index,
 138                                            s->in2out.addr.as_u32,
 139                                            s->out2in.addr.as_u32,
 140                                            s->in2out.protocol,
 141                                            s->in2out.port,
 142                                            s->out2in.port,
 143                                            s->in2out.fib_index);
 144
 145       nat_syslog_nat44_sdel (s->user_index, s->in2out.fib_index,
 146                              &s->in2out.addr, s->in2out.port,
 147                              &s->ext_host_nat_addr, s->ext_host_nat_port,
 148                              &s->out2in.addr, s->out2in.port,
 149                              &s->ext_host_addr, s->ext_host_port,
 150                              s->in2out.protocol, is_twice_nat_session (s));
 151
 152       nat_ha_sdel (&s->out2in.addr, s->out2in.port, &s->ext_host_addr,
 153                    s->ext_host_port, s->out2in.protocol, s->out2in.fib_index,
 154                    ctx->thread_index);
 155
 156       if (is_twice_nat_session (s))
 157         {
 158           for (i = 0; i < vec_len (sm->twice_nat_addresses); i++)
 159             {
 160               key.protocol = s->in2out.protocol;
 161               key.port = s->ext_host_nat_port;
 162               a = sm->twice_nat_addresses + i;
 163               if (a->addr.as_u32 == s->ext_host_nat_addr.as_u32)
 164                 {
 165                   snat_free_outside_address_and_port (sm->twice_nat_addresses,
 166                                                       ctx->thread_index,
 167                                                       &key);
 168                   break;
 169                 }
 170             }
 171         }
 172
 173       if (snat_is_session_static (s))
 174         goto delete;
 175
 176       snat_free_outside_address_and_port (sm->addresses, ctx->thread_index,
 177                                           &s->out2in);
 178     delete:
 179       nat44_delete_session (sm, s, ctx->thread_index);
 180       return 1;
 181     }
 182
 183   return 0;
 184 }
 185 #endif
 186
 187 static snat_session_t *
 188 create_session_for_static_mapping_ed (snat_main_t * sm,
 189                                       vlib_buffer_t * b,
 190                                       snat_session_key_t l_key,
 191                                       snat_session_key_t e_key,
 192                                       vlib_node_runtime_t * node,
 193                                       u32 thread_index,
 194                                       twice_nat_type_t twice_nat,
 195                                       lb_nat_type_t lb_nat, f64 now)
 196 {
 197   snat_session_t *s;
 198   snat_user_t *u;
 199   ip4_header_t *ip;
 200   udp_header_t *udp;
 201   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 202   clib_bihash_kv_16_8_t kv;
 203   snat_session_key_t eh_key;
 204   nat44_is_idle_session_ctx_t ctx;
 205
 206   nat44_session_try_cleanup (&l_key.addr, l_key.fib_index, thread_index, now);
 207
 208   if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
 209     {
 210       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 211       nat_elog_notice ("maximum sessions exceeded");
 212       return 0;
 213     }
 214
 215   u = nat_user_get_or_create (sm, &l_key.addr, l_key.fib_index, thread_index);
 216   if (!u)
 217     {
 218       nat_elog_warn ("create NAT user failed");
 219       return 0;
 220     }
 221
 222   s = nat_ed_session_alloc (sm, u, thread_index, now);
 223   if (!s)
 224     {
 225       nat44_delete_user_with_no_session (sm, u, thread_index);
 226       nat_elog_warn ("create NAT session failed");
 227       return 0;
 228     }
 229
 230   ip = vlib_buffer_get_current (b);
 231   udp = ip4_next_header (ip);
 232
 233   s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 234   s->ext_host_port = e_key.protocol == SNAT_PROTOCOL_ICMP ? 0 : udp->src_port;
 235   s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 236   if (lb_nat)
 237     s->flags |= SNAT_SESSION_FLAG_LOAD_BALANCING;
 238   if (lb_nat == AFFINITY_LB_NAT)
 239     s->flags |= SNAT_SESSION_FLAG_AFFINITY;
 240   s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 241   s->out2in = e_key;
 242   s->in2out = l_key;
 243   s->in2out.protocol = s->out2in.protocol;
 244   user_session_increment (sm, u, 1);
 245
 246   /* Add to lookup tables */
 247   make_ed_kv (&kv, &e_key.addr, &s->ext_host_addr, ip->protocol,
 248               e_key.fib_index, e_key.port, s->ext_host_port);
 249   kv.value = s - tsm->sessions;
 250   ctx.now = now;
 251   ctx.thread_index = thread_index;
 252   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->out2in_ed, &kv,
 253                                                nat44_o2i_ed_is_idle_session_cb,
 254                                                &ctx))
 255     nat_elog_notice ("out2in-ed key add failed");
 256
 257   if (twice_nat == TWICE_NAT || (twice_nat == TWICE_NAT_SELF &&
 258                                  ip->src_address.as_u32 == l_key.addr.as_u32))
 259     {
 260       eh_key.protocol = e_key.protocol;
 261       if (snat_alloc_outside_address_and_port (sm->twice_nat_addresses, 0,
 262                                                thread_index, &eh_key,
 263                                                sm->port_per_thread,
 264                                                tsm->snat_thread_index))
 265         {
 266           b->error = node->errors[NAT_OUT2IN_ED_ERROR_OUT_OF_PORTS];
 267           nat44_delete_session (sm, s, thread_index);
 268           if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &kv, 0))
 269             nat_elog_notice ("out2in-ed key del failed");
 270           return 0;
 271         }
 272       s->ext_host_nat_addr.as_u32 = eh_key.addr.as_u32;
 273       s->ext_host_nat_port = eh_key.port;
 274       s->flags |= SNAT_SESSION_FLAG_TWICE_NAT;
 275       make_ed_kv (&kv, &l_key.addr, &s->ext_host_nat_addr, ip->protocol,
 276                   l_key.fib_index, l_key.port, s->ext_host_nat_port);
 277     }
 278   else
 279     {
 280       make_ed_kv (&kv, &l_key.addr, &s->ext_host_addr, ip->protocol,
 281                   l_key.fib_index, l_key.port, s->ext_host_port);
 282     }
 283   kv.value = s - tsm->sessions;
 284   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->in2out_ed, &kv,
 285                                                nat44_i2o_ed_is_idle_session_cb,
 286                                                &ctx))
 287     nat_elog_notice ("in2out-ed key add failed");
 288
 289   snat_ipfix_logging_nat44_ses_create (thread_index,
 290                                        s->in2out.addr.as_u32,
 291                                        s->out2in.addr.as_u32,
 292                                        s->in2out.protocol,
 293                                        s->in2out.port,
 294                                        s->out2in.port, s->in2out.fib_index);
 295
 296   nat_syslog_nat44_sadd (s->user_index, s->in2out.fib_index,
 297                          &s->in2out.addr, s->in2out.port,
 298                          &s->ext_host_nat_addr, s->ext_host_nat_port,
 299                          &s->out2in.addr, s->out2in.port,
 300                          &s->ext_host_addr, s->ext_host_port,
 301                          s->in2out.protocol, is_twice_nat_session (s));
 302
 303   nat_ha_sadd (&s->in2out.addr, s->in2out.port, &s->out2in.addr,
 304                s->out2in.port, &s->ext_host_addr, s->ext_host_port,
 305                &s->ext_host_nat_addr, s->ext_host_nat_port,
 306                s->in2out.protocol, s->in2out.fib_index, s->flags,
 307                thread_index, 0);
 308
 309   return s;
 310 }
 311
 312 static int
 313 next_src_nat (snat_main_t * sm, ip4_header_t * ip, u8 proto, u16 src_port,
 314               u16 dst_port, u32 thread_index, u32 rx_fib_index)
 315 {
 316   clib_bihash_kv_16_8_t kv, value;
 317   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 318
 319   make_ed_kv (&kv, &ip->src_address, &ip->dst_address, proto,
 320               rx_fib_index, src_port, dst_port);
 321   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 322     return 1;
 323
 324   return 0;
 325 }
 326
 327 static void
 328 create_bypass_for_fwd (snat_main_t * sm, vlib_buffer_t * b, ip4_header_t * ip,
 329                        u32 rx_fib_index, u32 thread_index)
 330 {
 331   nat_ed_ses_key_t key;
 332   clib_bihash_kv_16_8_t kv, value;
 333   udp_header_t *udp;
 334   snat_user_t *u;
 335   snat_session_t *s = 0;
 336   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 337   f64 now = vlib_time_now (sm->vlib_main);
 338
 339   if (ip->protocol == IP_PROTOCOL_ICMP)
 340     {
 341       if (get_icmp_o2i_ed_key (b, ip, &key))
 342         return;
 343     }
 344   else if (ip->protocol == IP_PROTOCOL_UDP || ip->protocol == IP_PROTOCOL_TCP)
 345     {
 346       udp = ip4_next_header (ip);
 347       key.r_addr = ip->src_address;
 348       key.l_addr = ip->dst_address;
 349       key.proto = ip->protocol;
 350       key.l_port = udp->dst_port;
 351       key.r_port = udp->src_port;
 352     }
 353   else
 354     {
 355       key.r_addr = ip->src_address;
 356       key.l_addr = ip->dst_address;
 357       key.proto = ip->protocol;
 358       key.l_port = key.r_port = 0;
 359     }
 360   key.fib_index = 0;
 361   kv.key[0] = key.as_u64[0];
 362   kv.key[1] = key.as_u64[1];
 363
 364   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 365     {
 366       s = pool_elt_at_index (tsm->sessions, value.value);
 367     }
 368   else
 369     {
 370       u32 proto;
 371
 372       if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
 373         return;
 374
 375       u = nat_user_get_or_create (sm, &ip->dst_address, sm->inside_fib_index,
 376                                   thread_index);
 377       if (!u)
 378         {
 379           nat_elog_warn ("create NAT user failed");
 380           return;
 381         }
 382
 383       s = nat_ed_session_alloc (sm, u, thread_index, now);
 384       if (!s)
 385         {
 386           nat44_delete_user_with_no_session (sm, u, thread_index);
 387           nat_elog_warn ("create NAT session failed");
 388           return;
 389         }
 390
 391       proto = ip_proto_to_snat_proto (key.proto);
 392
 393       s->ext_host_addr = key.r_addr;
 394       s->ext_host_port = key.r_port;
 395       s->flags |= SNAT_SESSION_FLAG_FWD_BYPASS;
 396       s->out2in.addr = key.l_addr;
 397       s->out2in.port = key.l_port;
 398       s->out2in.protocol = proto;
 399       if (proto == ~0)
 400         {
 401           s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 402           s->out2in.port = ip->protocol;
 403         }
 404       s->out2in.fib_index = 0;
 405       s->in2out = s->out2in;
 406       user_session_increment (sm, u, 0);
 407
 408       kv.value = s - tsm->sessions;
 409       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &kv, 1))
 410         nat_elog_notice ("in2out_ed key add failed");
 411     }
 412
 413   if (ip->protocol == IP_PROTOCOL_TCP)
 414     {
 415       tcp_header_t *tcp = ip4_next_header (ip);
 416       if (nat44_set_tcp_session_state_o2i
 417           (sm, s, tcp->flags, tcp->ack_number, tcp->seq_number, thread_index))
 418         return;
 419     }
 420
 421   /* Accounting */
 422   nat44_session_update_counters (s, now, 0, thread_index);
 423   /* Per-user LRU list maintenance */
 424   nat44_session_update_lru (sm, s, thread_index);
 425 }
 426
 427 static inline void
 428 create_bypass_for_fwd_worker (snat_main_t * sm, vlib_buffer_t * b,
 429                               ip4_header_t * ip, u32 rx_fib_index)
 430 {
 431   ip4_header_t ip_wkr = {
 432     .src_address = ip->dst_address,
 433   };
 434   u32 thread_index = sm->worker_in2out_cb (&ip_wkr, rx_fib_index, 0);
 435
 436   create_bypass_for_fwd (sm, b, ip, rx_fib_index, thread_index);
 437 }
 438
 439 #ifndef CLIB_MARCH_VARIANT
 440 u32
 441 icmp_match_out2in_ed (snat_main_t * sm, vlib_node_runtime_t * node,
 442                       u32 thread_index, vlib_buffer_t * b, ip4_header_t * ip,
 443                       u8 * p_proto, snat_session_key_t * p_value,
 444                       u8 * p_dont_translate, void *d, void *e)
 445 {
 446   u32 next = ~0, sw_if_index, rx_fib_index;
 447   nat_ed_ses_key_t key;
 448   clib_bihash_kv_16_8_t kv, value;
 449   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 450   snat_session_t *s = 0;
 451   u8 dont_translate = 0, is_addr_only, identity_nat;
 452   snat_session_key_t e_key, l_key;
 453
 454   sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
 455   rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 456
 457   if (get_icmp_o2i_ed_key (b, ip, &key))
 458     {
 459       b->error = node->errors[NAT_OUT2IN_ED_ERROR_UNSUPPORTED_PROTOCOL];
 460       next = NAT_NEXT_DROP;
 461       goto out;
 462     }
 463   key.fib_index = rx_fib_index;
 464   kv.key[0] = key.as_u64[0];
 465   kv.key[1] = key.as_u64[1];
 466
 467   if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv, &value))
 468     {
 469       /* Try to match static mapping */
 470       e_key.addr = ip->dst_address;
 471       e_key.port = key.l_port;
 472       e_key.protocol = ip_proto_to_snat_proto (key.proto);
 473       e_key.fib_index = rx_fib_index;
 474       if (snat_static_mapping_match
 475           (sm, e_key, &l_key, 1, &is_addr_only, 0, 0, 0, &identity_nat))
 476         {
 477           if (!sm->forwarding_enabled)
 478             {
 479               /* Don't NAT packet aimed at the intfc address */
 480               if (PREDICT_FALSE (is_interface_addr (sm, node, sw_if_index,
 481                                                     ip->dst_address.as_u32)))
 482                 {
 483                   dont_translate = 1;
 484                   goto out;
 485                 }
 486               b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 487               next = NAT_NEXT_DROP;
 488               goto out;
 489             }
 490           else
 491             {
 492               dont_translate = 1;
 493               if (next_src_nat (sm, ip, key.proto, key.l_port, key.r_port,
 494                                 thread_index, rx_fib_index))
 495                 {
 496                   next = NAT_NEXT_IN2OUT_ED_FAST_PATH;
 497                   goto out;
 498                 }
 499               if (sm->num_workers > 1)
 500                 create_bypass_for_fwd_worker (sm, b, ip, rx_fib_index);
 501               else
 502                 create_bypass_for_fwd (sm, b, ip, rx_fib_index, thread_index);
 503               goto out;
 504             }
 505         }
 506
 507       if (PREDICT_FALSE
 508           (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 509            ICMP4_echo_reply
 510            && (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 511                ICMP4_echo_request || !is_addr_only)))
 512         {
 513           b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 514           next = NAT_NEXT_DROP;
 515           goto out;
 516         }
 517
 518       if (PREDICT_FALSE (identity_nat))
 519         {
 520           dont_translate = 1;
 521           goto out;
 522         }
 523
 524       /* Create session initiated by host from external network */
 525       s = create_session_for_static_mapping_ed (sm, b, l_key, e_key, node,
 526                                                 thread_index, 0, 0,
 527                                                 vlib_time_now
 528                                                 (sm->vlib_main));
 529
 530       if (!s)
 531         {
 532           next = NAT_NEXT_DROP;
 533           goto out;
 534         }
 535     }
 536   else
 537     {
 538       if (PREDICT_FALSE
 539           (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 540            ICMP4_echo_reply
 541            && vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 542            ICMP4_echo_request
 543            && !icmp_type_is_error_message (vnet_buffer (b)->ip.
 544                                            reass.icmp_type_or_tcp_flags)))
 545         {
 546           b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 547           next = NAT_NEXT_DROP;
 548           goto out;
 549         }
 550
 551       s = pool_elt_at_index (tsm->sessions, value.value);
 552     }
 553
 554   *p_proto = ip_proto_to_snat_proto (key.proto);
 555 out:
 556   if (s)
 557     *p_value = s->in2out;
 558   *p_dont_translate = dont_translate;
 559   if (d)
 560     *(snat_session_t **) d = s;
 561   return next;
 562 }
 563 #endif
 564
 565 static snat_session_t *
 566 nat44_ed_out2in_unknown_proto (snat_main_t * sm,
 567                                vlib_buffer_t * b,
 568                                ip4_header_t * ip,
 569                                u32 rx_fib_index,
 570                                u32 thread_index,
 571                                f64 now,
 572                                vlib_main_t * vm, vlib_node_runtime_t * node)
 573 {
 574   clib_bihash_kv_8_8_t kv, value;
 575   clib_bihash_kv_16_8_t s_kv, s_value;
 576   snat_static_mapping_t *m;
 577   u32 old_addr, new_addr;
 578   ip_csum_t sum;
 579   snat_session_t *s;
 580   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 581   snat_user_t *u;
 582
 583   old_addr = ip->dst_address.as_u32;
 584
 585   make_ed_kv (&s_kv, &ip->dst_address, &ip->src_address, ip->protocol,
 586               rx_fib_index, 0, 0);
 587
 588   if (!clib_bihash_search_16_8 (&tsm->out2in_ed, &s_kv, &s_value))
 589     {
 590       s = pool_elt_at_index (tsm->sessions, s_value.value);
 591       new_addr = ip->dst_address.as_u32 = s->in2out.addr.as_u32;
 592     }
 593   else
 594     {
 595       if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
 596         {
 597           b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 598           nat_elog_notice ("maximum sessions exceeded");
 599           return 0;
 600         }
 601
 602       make_sm_kv (&kv, &ip->dst_address, 0, 0, 0);
 603       if (clib_bihash_search_8_8
 604           (&sm->static_mapping_by_external, &kv, &value))
 605         {
 606           b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 607           return 0;
 608         }
 609
 610       m = pool_elt_at_index (sm->static_mappings, value.value);
 611
 612       new_addr = ip->dst_address.as_u32 = m->local_addr.as_u32;
 613
 614       u = nat_user_get_or_create (sm, &m->local_addr, m->fib_index,
 615                                   thread_index);
 616       if (!u)
 617         {
 618           nat_elog_warn ("create NAT user failed");
 619           return 0;
 620         }
 621
 622       /* Create a new session */
 623       s = nat_ed_session_alloc (sm, u, thread_index, now);
 624       if (!s)
 625         {
 626           nat44_delete_user_with_no_session (sm, u, thread_index);
 627           nat_elog_warn ("create NAT session failed");
 628           return 0;
 629         }
 630
 631       s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 632       s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 633       s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 634       s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 635       s->out2in.addr.as_u32 = old_addr;
 636       s->out2in.fib_index = rx_fib_index;
 637       s->in2out.addr.as_u32 = new_addr;
 638       s->in2out.fib_index = m->fib_index;
 639       s->in2out.port = s->out2in.port = ip->protocol;
 640       user_session_increment (sm, u, 1);
 641
 642       /* Add to lookup tables */
 643       s_kv.value = s - tsm->sessions;
 644       if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &s_kv, 1))
 645         nat_elog_notice ("out2in key add failed");
 646
 647       make_ed_kv (&s_kv, &ip->dst_address, &ip->src_address, ip->protocol,
 648                   m->fib_index, 0, 0);
 649       s_kv.value = s - tsm->sessions;
 650       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &s_kv, 1))
 651         nat_elog_notice ("in2out key add failed");
 652     }
 653
 654   /* Update IP checksum */
 655   sum = ip->checksum;
 656   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
 657   ip->checksum = ip_csum_fold (sum);
 658
 659   vnet_buffer (b)->sw_if_index[VLIB_TX] = s->in2out.fib_index;
 660
 661   /* Accounting */
 662   nat44_session_update_counters (s, now, vlib_buffer_length_in_chain (vm, b),
 663                                  thread_index);
 664   /* Per-user LRU list maintenance */
 665   nat44_session_update_lru (sm, s, thread_index);
 666
 667   return s;
 668 }
 669
 670 static inline uword
 671 nat44_ed_out2in_fast_path_node_fn_inline (vlib_main_t * vm,
 672                                           vlib_node_runtime_t * node,
 673                                           vlib_frame_t * frame)
 674 {
 675   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
 676   nat_next_t next_index;
 677   snat_main_t *sm = &snat_main;
 678   f64 now = vlib_time_now (vm);
 679   u32 thread_index = vm->thread_index;
 680   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 681   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 682     0, fragments = 0;
 683
 684   stats_node_index = sm->ed_out2in_node_index;
 685
 686   from = vlib_frame_vector_args (frame);
 687   n_left_from = frame->n_vectors;
 688   next_index = node->cached_next_index;
 689
 690   while (n_left_from > 0)
 691     {
 692       u32 n_left_to_next;
 693
 694       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 695
 696       while (n_left_from > 0 && n_left_to_next > 0)
 697         {
 698           u32 bi0;
 699           vlib_buffer_t *b0;
 700           u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
 701             new_addr0;
 702           u16 old_port0, new_port0;
 703           ip4_header_t *ip0;
 704           udp_header_t *udp0;
 705           tcp_header_t *tcp0;
 706           snat_session_t *s0 = 0;
 707           clib_bihash_kv_16_8_t kv0, value0;
 708           ip_csum_t sum0;
 709
 710           /* speculatively enqueue b0 to the current next frame */
 711           bi0 = from[0];
 712           to_next[0] = bi0;
 713           from += 1;
 714           to_next += 1;
 715           n_left_from -= 1;
 716           n_left_to_next -= 1;
 717
 718           b0 = vlib_get_buffer (vm, bi0);
 719           next0 = nat_buffer_opaque (b0)->arc_next;
 720
 721           vnet_buffer (b0)->snat.flags = 0;
 722           ip0 = vlib_buffer_get_current (b0);
 723
 724           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 725           rx_fib_index0 =
 726             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 727                                                  sw_if_index0);
 728
 729           if (PREDICT_FALSE (ip0->ttl == 1))
 730             {
 731               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 732               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 733                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 734                                            0);
 735               next0 = NAT_NEXT_ICMP_ERROR;
 736               goto trace0;
 737             }
 738
 739           udp0 = ip4_next_header (ip0);
 740           tcp0 = (tcp_header_t *) udp0;
 741           proto0 = ip_proto_to_snat_proto (ip0->protocol);
 742
 743           if (PREDICT_FALSE (proto0 == ~0))
 744             {
 745               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 746               goto trace0;
 747             }
 748
 749           if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
 750             {
 751               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 752               goto trace0;
 753             }
 754
 755           make_ed_kv (&kv0, &ip0->dst_address, &ip0->src_address,
 756                       ip0->protocol, rx_fib_index0,
 757                       vnet_buffer (b0)->ip.reass.l4_dst_port,
 758                       vnet_buffer (b0)->ip.reass.l4_src_port);
 759
 760           if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv0, &value0))
 761             {
 762               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 763               goto trace0;
 764             }
 765           s0 = pool_elt_at_index (tsm->sessions, value0.value);
 766
 767           old_addr0 = ip0->dst_address.as_u32;
 768           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
 769           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
 770
 771           sum0 = ip0->checksum;
 772           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 773                                  dst_address);
 774           if (PREDICT_FALSE (is_twice_nat_session (s0)))
 775             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 776                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
 777                                    src_address);
 778           ip0->checksum = ip_csum_fold (sum0);
 779
 780           old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
 781
 782           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
 783             {
 784               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 785                 {
 786                   new_port0 = udp0->dst_port = s0->in2out.port;
 787                   sum0 = tcp0->checksum;
 788                   sum0 =
 789                     ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 790                                     dst_address);
 791                   sum0 =
 792                     ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 793                                     length);
 794                   if (is_twice_nat_session (s0))
 795                     {
 796                       sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 797                                              s0->ext_host_nat_addr.as_u32,
 798                                              ip4_header_t, dst_address);
 799                       sum0 =
 800                         ip_csum_update (sum0,
 801                                         vnet_buffer (b0)->ip.
 802                                         reass.l4_src_port,
 803                                         s0->ext_host_nat_port, ip4_header_t,
 804                                         length);
 805                       tcp0->src_port = s0->ext_host_nat_port;
 806                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 807                     }
 808                   tcp0->checksum = ip_csum_fold (sum0);
 809                 }
 810               tcp_packets++;
 811               if (nat44_set_tcp_session_state_o2i
 812                   (sm, s0, vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags,
 813                    vnet_buffer (b0)->ip.reass.tcp_ack_number,
 814                    vnet_buffer (b0)->ip.reass.tcp_seq_number, thread_index))
 815                 goto trace0;
 816             }
 817           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
 818                    && udp0->checksum)
 819             {
 820               new_port0 = udp0->dst_port = s0->in2out.port;
 821               sum0 = udp0->checksum;
 822               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 823                                      dst_address);
 824               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 825                                      length);
 826               if (PREDICT_FALSE (is_twice_nat_session (s0)))
 827                 {
 828                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 829                                          s0->ext_host_nat_addr.as_u32,
 830                                          ip4_header_t, dst_address);
 831                   sum0 =
 832                     ip_csum_update (sum0,
 833                                     vnet_buffer (b0)->ip.reass.l4_src_port,
 834                                     s0->ext_host_nat_port, ip4_header_t,
 835                                     length);
 836                   udp0->src_port = s0->ext_host_nat_port;
 837                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 838                 }
 839               udp0->checksum = ip_csum_fold (sum0);
 840               udp_packets++;
 841             }
 842           else
 843             {
 844               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 845                 {
 846                   new_port0 = udp0->dst_port = s0->in2out.port;
 847                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
 848                     {
 849                       udp0->src_port = s0->ext_host_nat_port;
 850                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 851                     }
 852                 }
 853               udp_packets++;
 854             }
 855
 856           /* Accounting */
 857           nat44_session_update_counters (s0, now,
 858                                          vlib_buffer_length_in_chain (vm, b0),
 859                                          thread_index);
 860           /* Per-user LRU list maintenance */
 861           nat44_session_update_lru (sm, s0, thread_index);
 862
 863         trace0:
 864           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 865                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 866             {
 867               nat44_ed_out2in_trace_t *t =
 868                 vlib_add_trace (vm, node, b0, sizeof (*t));
 869               t->sw_if_index = sw_if_index0;
 870               t->next_index = next0;
 871               t->is_slow_path = 0;
 872
 873               if (s0)
 874                 t->session_index = s0 - tsm->sessions;
 875               else
 876                 t->session_index = ~0;
 877             }
 878
 879           pkts_processed += next0 == nat_buffer_opaque (b0)->arc_next;
 880           /* verify speculative enqueue, maybe switch current next frame */
 881           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 882                                            to_next, n_left_to_next,
 883                                            bi0, next0);
 884         }
 885
 886       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 887     }
 888
 889   vlib_node_increment_counter (vm, stats_node_index,
 890                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
 891                                pkts_processed);
 892   vlib_node_increment_counter (vm, stats_node_index,
 893                                NAT_OUT2IN_ED_ERROR_TCP_PACKETS, tcp_packets);
 894   vlib_node_increment_counter (vm, stats_node_index,
 895                                NAT_OUT2IN_ED_ERROR_UDP_PACKETS, udp_packets);
 896   vlib_node_increment_counter (vm, stats_node_index,
 897                                NAT_OUT2IN_ED_ERROR_ICMP_PACKETS,
 898                                icmp_packets);
 899   vlib_node_increment_counter (vm, stats_node_index,
 900                                NAT_OUT2IN_ED_ERROR_OTHER_PACKETS,
 901                                other_packets);
 902   vlib_node_increment_counter (vm, stats_node_index,
 903                                NAT_OUT2IN_ED_ERROR_FRAGMENTS, fragments);
 904   return frame->n_vectors;
 905 }
 906
 907 static inline uword
 908 nat44_ed_out2in_slow_path_node_fn_inline (vlib_main_t * vm,
 909                                           vlib_node_runtime_t * node,
 910                                           vlib_frame_t * frame)
 911 {
 912   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
 913   nat_next_t next_index;
 914   snat_main_t *sm = &snat_main;
 915   f64 now = vlib_time_now (vm);
 916   u32 thread_index = vm->thread_index;
 917   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 918   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 919     0, fragments = 0;
 920
 921   stats_node_index = sm->ed_out2in_slowpath_node_index;
 922
 923   from = vlib_frame_vector_args (frame);
 924   n_left_from = frame->n_vectors;
 925   next_index = node->cached_next_index;
 926
 927   while (n_left_from > 0)
 928     {
 929       u32 n_left_to_next;
 930
 931       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 932
 933       while (n_left_from > 0 && n_left_to_next > 0)
 934         {
 935           u32 bi0;
 936           vlib_buffer_t *b0;
 937           u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
 938             new_addr0;
 939           u16 old_port0, new_port0;
 940           ip4_header_t *ip0;
 941           udp_header_t *udp0;
 942           tcp_header_t *tcp0;
 943           icmp46_header_t *icmp0;
 944           snat_session_t *s0 = 0;
 945           clib_bihash_kv_16_8_t kv0, value0;
 946           ip_csum_t sum0;
 947           snat_session_key_t e_key0, l_key0;
 948           lb_nat_type_t lb_nat0;
 949           twice_nat_type_t twice_nat0;
 950           u8 identity_nat0;
 951
 952           /* speculatively enqueue b0 to the current next frame */
 953           bi0 = from[0];
 954           to_next[0] = bi0;
 955           from += 1;
 956           to_next += 1;
 957           n_left_from -= 1;
 958           n_left_to_next -= 1;
 959
 960           b0 = vlib_get_buffer (vm, bi0);
 961           next0 = nat_buffer_opaque (b0)->arc_next;
 962
 963           vnet_buffer (b0)->snat.flags = 0;
 964           ip0 = vlib_buffer_get_current (b0);
 965
 966           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 967           rx_fib_index0 =
 968             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 969                                                  sw_if_index0);
 970
 971           if (PREDICT_FALSE (ip0->ttl == 1))
 972             {
 973               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 974               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 975                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 976                                            0);
 977               next0 = NAT_NEXT_ICMP_ERROR;
 978               goto trace0;
 979             }
 980
 981           udp0 = ip4_next_header (ip0);
 982           tcp0 = (tcp_header_t *) udp0;
 983           icmp0 = (icmp46_header_t *) udp0;
 984           proto0 = ip_proto_to_snat_proto (ip0->protocol);
 985
 986           if (PREDICT_FALSE (proto0 == ~0))
 987             {
 988               s0 =
 989                 nat44_ed_out2in_unknown_proto (sm, b0, ip0, rx_fib_index0,
 990                                                thread_index, now, vm, node);
 991               other_packets++;
 992               if (!sm->forwarding_enabled)
 993                 {
 994                   if (!s0)
 995                     next0 = NAT_NEXT_DROP;
 996                   goto trace0;
 997                 }
 998             }
 999
1000           if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1001             {
1002               next0 = icmp_out2in_ed_slow_path
1003                 (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1004                  next0, now, thread_index, &s0);
1005               icmp_packets++;
1006               goto trace0;
1007             }
1008
1009           make_ed_kv (&kv0, &ip0->dst_address, &ip0->src_address,
1010                       ip0->protocol, rx_fib_index0,
1011                       vnet_buffer (b0)->ip.reass.l4_dst_port,
1012                       vnet_buffer (b0)->ip.reass.l4_src_port);
1013
1014           if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv0, &value0))
1015             {
1016               /* Try to match static mapping by external address and port,
1017                  destination address and port in packet */
1018               e_key0.addr = ip0->dst_address;
1019               e_key0.port = vnet_buffer (b0)->ip.reass.l4_dst_port;
1020               e_key0.protocol = proto0;
1021               e_key0.fib_index = rx_fib_index0;
1022
1023               if (snat_static_mapping_match (sm, e_key0, &l_key0, 1, 0,
1024                                              &twice_nat0, &lb_nat0,
1025                                              &ip0->src_address,
1026                                              &identity_nat0))
1027                 {
1028                   /*
1029                    * Send DHCP packets to the ipv4 stack, or we won't
1030                    * be able to use dhcp client on the outside interface
1031                    */
1032                   if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_UDP
1033                                      && (vnet_buffer (b0)->ip.
1034                                          reass.l4_dst_port ==
1035                                          clib_host_to_net_u16
1036                                          (UDP_DST_PORT_dhcp_to_client))))
1037                     {
1038                       goto trace0;
1039                     }
1040
1041                   if (!sm->forwarding_enabled)
1042                     {
1043                       b0->error =
1044                         node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
1045                       next0 = NAT_NEXT_DROP;
1046                     }
1047                   else
1048                     {
1049                       if (next_src_nat (sm, ip0, ip0->protocol,
1050                                         vnet_buffer (b0)->ip.
1051                                         reass.l4_src_port,
1052                                         vnet_buffer (b0)->ip.
1053                                         reass.l4_dst_port, thread_index,
1054                                         rx_fib_index0))
1055                         {
1056                           next0 = NAT_NEXT_IN2OUT_ED_FAST_PATH;
1057                           goto trace0;
1058                         }
1059                       if (sm->num_workers > 1)
1060                         create_bypass_for_fwd_worker (sm, b0, ip0,
1061                                                       rx_fib_index0);
1062                       else
1063                         create_bypass_for_fwd (sm, b0, ip0, rx_fib_index0,
1064                                                thread_index);
1065                     }
1066                   goto trace0;
1067                 }
1068
1069               if (PREDICT_FALSE (identity_nat0))
1070                 goto trace0;
1071
1072               if ((proto0 == SNAT_PROTOCOL_TCP)
1073                   && !tcp_flags_is_init (vnet_buffer (b0)->ip.
1074                                          reass.icmp_type_or_tcp_flags))
1075                 {
1076                   b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
1077                   next0 = NAT_NEXT_DROP;
1078                   goto trace0;
1079                 }
1080
1081               /* Create session initiated by host from external network */
1082               s0 = create_session_for_static_mapping_ed (sm, b0, l_key0,
1083                                                          e_key0, node,
1084                                                          thread_index,
1085                                                          twice_nat0,
1086                                                          lb_nat0, now);
1087               if (!s0)
1088                 {
1089                   next0 = NAT_NEXT_DROP;
1090                   goto trace0;
1091                 }
1092             }
1093           else
1094             {
1095               s0 = pool_elt_at_index (tsm->sessions, value0.value);
1096             }
1097
1098           old_addr0 = ip0->dst_address.as_u32;
1099           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
1100           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
1101
1102           sum0 = ip0->checksum;
1103           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1104                                  dst_address);
1105           if (PREDICT_FALSE (is_twice_nat_session (s0)))
1106             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1107                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
1108                                    src_address);
1109           ip0->checksum = ip_csum_fold (sum0);
1110
1111           old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
1112
1113           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
1114             {
1115               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1116                 {
1117                   new_port0 = udp0->dst_port = s0->in2out.port;
1118                   sum0 = tcp0->checksum;
1119                   sum0 =
1120                     ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1121                                     dst_address);
1122                   sum0 =
1123                     ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1124                                     length);
1125                   if (is_twice_nat_session (s0))
1126                     {
1127                       sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1128                                              s0->ext_host_nat_addr.as_u32,
1129                                              ip4_header_t, dst_address);
1130                       sum0 =
1131                         ip_csum_update (sum0,
1132                                         vnet_buffer (b0)->ip.
1133                                         reass.l4_src_port,
1134                                         s0->ext_host_nat_port, ip4_header_t,
1135                                         length);
1136                       tcp0->src_port = s0->ext_host_nat_port;
1137                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1138                     }
1139                   tcp0->checksum = ip_csum_fold (sum0);
1140                 }
1141               tcp_packets++;
1142               if (nat44_set_tcp_session_state_o2i
1143                   (sm, s0, vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags,
1144                    vnet_buffer (b0)->ip.reass.tcp_ack_number,
1145                    vnet_buffer (b0)->ip.reass.tcp_seq_number, thread_index))
1146                 goto trace0;
1147             }
1148           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
1149                    && udp0->checksum)
1150             {
1151               new_port0 = udp0->dst_port = s0->in2out.port;
1152               sum0 = udp0->checksum;
1153               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1154                                      dst_address);
1155               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1156                                      length);
1157               if (PREDICT_FALSE (is_twice_nat_session (s0)))
1158                 {
1159                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1160                                          s0->ext_host_nat_addr.as_u32,
1161                                          ip4_header_t, dst_address);
1162                   sum0 =
1163                     ip_csum_update (sum0,
1164                                     vnet_buffer (b0)->ip.reass.l4_src_port,
1165                                     s0->ext_host_nat_port, ip4_header_t,
1166                                     length);
1167                   udp0->src_port = s0->ext_host_nat_port;
1168                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1169                 }
1170               udp0->checksum = ip_csum_fold (sum0);
1171               udp_packets++;
1172             }
1173           else
1174             {
1175               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1176                 {
1177                   new_port0 = udp0->dst_port = s0->in2out.port;
1178                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
1179                     {
1180                       udp0->src_port = s0->ext_host_nat_port;
1181                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1182                     }
1183                 }
1184               udp_packets++;
1185             }
1186
1187           /* Accounting */
1188           nat44_session_update_counters (s0, now,
1189                                          vlib_buffer_length_in_chain (vm, b0),
1190                                          thread_index);
1191           /* Per-user LRU list maintenance */
1192           nat44_session_update_lru (sm, s0, thread_index);
1193
1194         trace0:
1195           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1196                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1197             {
1198               nat44_ed_out2in_trace_t *t =
1199                 vlib_add_trace (vm, node, b0, sizeof (*t));
1200               t->sw_if_index = sw_if_index0;
1201               t->next_index = next0;
1202               t->is_slow_path = 1;
1203
1204               if (s0)
1205                 t->session_index = s0 - tsm->sessions;
1206               else
1207                 t->session_index = ~0;
1208             }
1209
1210           pkts_processed += next0 == nat_buffer_opaque (b0)->arc_next;
1211           /* verify speculative enqueue, maybe switch current next frame */
1212           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1213                                            to_next, n_left_to_next,
1214                                            bi0, next0);
1215         }
1216
1217       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1218     }
1219
1220   vlib_node_increment_counter (vm, stats_node_index,
1221                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
1222                                pkts_processed);
1223   vlib_node_increment_counter (vm, stats_node_index,
1224                                NAT_OUT2IN_ED_ERROR_TCP_PACKETS, tcp_packets);
1225   vlib_node_increment_counter (vm, stats_node_index,
1226                                NAT_OUT2IN_ED_ERROR_UDP_PACKETS, udp_packets);
1227   vlib_node_increment_counter (vm, stats_node_index,
1228                                NAT_OUT2IN_ED_ERROR_ICMP_PACKETS,
1229                                icmp_packets);
1230   vlib_node_increment_counter (vm, stats_node_index,
1231                                NAT_OUT2IN_ED_ERROR_OTHER_PACKETS,
1232                                other_packets);
1233   vlib_node_increment_counter (vm, stats_node_index,
1234                                NAT_OUT2IN_ED_ERROR_FRAGMENTS, fragments);
1235   return frame->n_vectors;
1236 }
1237
1238 VLIB_NODE_FN (nat44_ed_out2in_node) (vlib_main_t * vm,
1239                                      vlib_node_runtime_t * node,
1240                                      vlib_frame_t * frame)
1241 {
1242   return nat44_ed_out2in_fast_path_node_fn_inline (vm, node, frame);
1243 }
1244
1245 /* *INDENT-OFF* */
1246 VLIB_REGISTER_NODE (nat44_ed_out2in_node) = {
1247   .name = "nat44-ed-out2in",
1248   .vector_size = sizeof (u32),
1249   .sibling_of = "nat-default",
1250   .format_trace = format_nat44_ed_out2in_trace,
1251   .type = VLIB_NODE_TYPE_INTERNAL,
1252   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1253   .error_strings = nat_out2in_ed_error_strings,
1254   .runtime_data_bytes = sizeof (snat_runtime_t),
1255 };
1256 /* *INDENT-ON* */
1257
1258 VLIB_NODE_FN (nat44_ed_out2in_slowpath_node) (vlib_main_t * vm,
1259                                               vlib_node_runtime_t * node,
1260                                               vlib_frame_t * frame)
1261 {
1262   return nat44_ed_out2in_slow_path_node_fn_inline (vm, node, frame);
1263 }
1264
1265 /* *INDENT-OFF* */
1266 VLIB_REGISTER_NODE (nat44_ed_out2in_slowpath_node) = {
1267   .name = "nat44-ed-out2in-slowpath",
1268   .vector_size = sizeof (u32),
1269   .sibling_of = "nat-default",
1270   .format_trace = format_nat44_ed_out2in_trace,
1271   .type = VLIB_NODE_TYPE_INTERNAL,
1272   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1273   .error_strings = nat_out2in_ed_error_strings,
1274   .runtime_data_bytes = sizeof (snat_runtime_t),
1275 };
1276 /* *INDENT-ON* */
1277
1278 static u8 *
1279 format_nat_pre_trace (u8 * s, va_list * args)
1280 {
1281   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1282   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1283   nat_pre_trace_t *t = va_arg (*args, nat_pre_trace_t *);
1284   return format (s, "out2in next_index %d", t->next_index);
1285 }
1286
1287 VLIB_NODE_FN (nat_pre_out2in_node) (vlib_main_t * vm,
1288                                     vlib_node_runtime_t * node,
1289                                     vlib_frame_t * frame)
1290 {
1291   return nat_pre_node_fn_inline (vm, node, frame,
1292                                  NAT_NEXT_OUT2IN_ED_FAST_PATH);
1293 }
1294
1295 /* *INDENT-OFF* */
1296 VLIB_REGISTER_NODE (nat_pre_out2in_node) = {
1297   .name = "nat-pre-out2in",
1298   .vector_size = sizeof (u32),
1299   .sibling_of = "nat-default",
1300   .format_trace = format_nat_pre_trace,
1301   .type = VLIB_NODE_TYPE_INTERNAL,
1302   .n_errors = 0,
1303  };
1304 /* *INDENT-ON* */
1305
1306 /*
1307  * fd.io coding-style-patch-verification: ON
1308  *
1309  * Local Variables:
1310  * eval: (c-set-style "gnu")
1311  * End:
1312  */