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 #include <nat/nat44/ed_inlines.h>
  35
  36 static char *nat_out2in_ed_error_strings[] = {
  37 #define _(sym,string) string,
  38   foreach_nat_out2in_ed_error
  39 #undef _
  40 };
  41
  42 typedef struct
  43 {
  44   u32 sw_if_index;
  45   u32 next_index;
  46   u32 session_index;
  47   u32 is_slow_path;
  48 } nat44_ed_out2in_trace_t;
  49
  50 static u8 *
  51 format_nat44_ed_out2in_trace (u8 * s, va_list * args)
  52 {
  53   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  54   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  55   nat44_ed_out2in_trace_t *t = va_arg (*args, nat44_ed_out2in_trace_t *);
  56   char *tag;
  57
  58   tag =
  59     t->is_slow_path ? "NAT44_OUT2IN_ED_SLOW_PATH" :
  60     "NAT44_OUT2IN_ED_FAST_PATH";
  61
  62   s = format (s, "%s: sw_if_index %d, next index %d, session %d", tag,
  63               t->sw_if_index, t->next_index, t->session_index);
  64
  65   return s;
  66 }
  67
  68 static inline u32
  69 icmp_out2in_ed_slow_path (snat_main_t * sm, vlib_buffer_t * b0,
  70                           ip4_header_t * ip0, icmp46_header_t * icmp0,
  71                           u32 sw_if_index0, u32 rx_fib_index0,
  72                           vlib_node_runtime_t * node, u32 next0, f64 now,
  73                           u32 thread_index, snat_session_t ** p_s0)
  74 {
  75   vlib_main_t *vm = vlib_get_main ();
  76
  77   next0 = icmp_out2in (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
  78                        next0, thread_index, p_s0, 0);
  79   snat_session_t *s0 = *p_s0;
  80   if (PREDICT_TRUE (next0 != NAT_NEXT_DROP && s0))
  81     {
  82       /* Accounting */
  83       nat44_session_update_counters (s0, now,
  84                                      vlib_buffer_length_in_chain
  85                                      (vm, b0), thread_index);
  86       /* Per-user LRU list maintenance */
  87       nat44_session_update_lru (sm, s0, thread_index);
  88     }
  89   return next0;
  90 }
  91
  92 #ifndef CLIB_MARCH_VARIANT
  93 int
  94 nat44_o2i_ed_is_idle_session_cb (clib_bihash_kv_16_8_t * kv, void *arg)
  95 {
  96   snat_main_t *sm = &snat_main;
  97   nat44_is_idle_session_ctx_t *ctx = arg;
  98   snat_session_t *s;
  99   u64 sess_timeout_time;
 100   u8 proto;
 101   u16 r_port, l_port;
 102   ip4_address_t *l_addr, *r_addr;
 103   u32 fib_index;
 104   clib_bihash_kv_16_8_t ed_kv;
 105   int i;
 106   //snat_address_t *a;
 107   snat_main_per_thread_data_t *tsm = vec_elt_at_index (sm->per_thread_data,
 108                                                        ctx->thread_index);
 109
 110   s = pool_elt_at_index (tsm->sessions, kv->value);
 111   sess_timeout_time = s->last_heard + (f64) nat44_session_get_timeout (sm, s);
 112   if (ctx->now >= sess_timeout_time)
 113     {
 114       l_addr = &s->in2out.addr;
 115       r_addr = &s->ext_host_addr;
 116       fib_index = s->in2out.fib_index;
 117       if (snat_is_unk_proto_session (s))
 118         {
 119           proto = s->in2out.port;
 120           r_port = 0;
 121           l_port = 0;
 122         }
 123       else
 124         {
 125           proto = nat_proto_to_ip_proto (s->nat_proto);
 126           l_port = s->in2out.port;
 127           r_port = s->ext_host_port;
 128         }
 129       if (is_twice_nat_session (s))
 130         {
 131           r_addr = &s->ext_host_nat_addr;
 132           r_port = s->ext_host_nat_port;
 133         }
 134       init_ed_k (&ed_kv, *l_addr, l_port, *r_addr, r_port, fib_index, proto);
 135       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &ed_kv, 0))
 136         nat_elog_warn ("in2out_ed key del failed");
 137
 138       if (snat_is_unk_proto_session (s))
 139         goto delete;
 140
 141       snat_ipfix_logging_nat44_ses_delete (ctx->thread_index,
 142                                            s->in2out.addr.as_u32,
 143                                            s->out2in.addr.as_u32,
 144                                            s->nat_proto,
 145                                            s->in2out.port,
 146                                            s->out2in.port,
 147                                            s->in2out.fib_index);
 148
 149       nat_syslog_nat44_sdel (s->user_index, s->in2out.fib_index,
 150                              &s->in2out.addr, s->in2out.port,
 151                              &s->ext_host_nat_addr, s->ext_host_nat_port,
 152                              &s->out2in.addr, s->out2in.port,
 153                              &s->ext_host_addr, s->ext_host_port,
 154                              s->nat_proto, is_twice_nat_session (s));
 155
 156       nat_ha_sdel (&s->out2in.addr, s->out2in.port, &s->ext_host_addr,
 157                    s->ext_host_port, s->nat_proto, s->out2in.fib_index,
 158                    ctx->thread_index);
 159
 160       if (is_twice_nat_session (s))
 161         {
 162           for (i = 0; i < vec_len (sm->twice_nat_addresses); i++)
 163             {
 164               // FIXME TODO this is obviously wrong code ... needs fix!
 165               //       key.protocol = s->nat_proto;
 166               //       key.port = s->ext_host_nat_port;
 167               //       a = sm->twice_nat_addresses + i;
 168               //       if (a->addr.as_u32 == s->ext_host_nat_addr.as_u32)
 169               //      {
 170               //        snat_free_outside_address_and_port (sm->twice_nat_addresses,
 171               //                                            ctx->thread_index,
 172               //                                            &key);
 173               //        break;
 174               //      }
 175             }
 176         }
 177
 178       if (snat_is_session_static (s))
 179         goto delete;
 180
 181       snat_free_outside_address_and_port (sm->addresses, ctx->thread_index,
 182                                           &s->out2in.addr, s->out2in.port,
 183                                           s->nat_proto);
 184     delete:
 185       nat_ed_session_delete (sm, s, ctx->thread_index, 1);
 186       return 1;
 187     }
 188
 189   return 0;
 190 }
 191 #endif
 192
 193 static snat_session_t *
 194 create_session_for_static_mapping_ed (snat_main_t * sm,
 195                                       vlib_buffer_t * b,
 196                                       ip4_address_t i2o_addr,
 197                                       u16 i2o_port,
 198                                       u32 i2o_fib_index,
 199                                       ip4_address_t o2i_addr,
 200                                       u16 o2i_port,
 201                                       u32 o2i_fib_index,
 202                                       nat_protocol_t nat_proto,
 203                                       vlib_node_runtime_t * node,
 204                                       u32 rx_fib_index,
 205                                       u32 thread_index,
 206                                       twice_nat_type_t twice_nat,
 207                                       lb_nat_type_t lb_nat, f64 now)
 208 {
 209   snat_session_t *s;
 210   ip4_header_t *ip;
 211   udp_header_t *udp;
 212   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 213   clib_bihash_kv_16_8_t kv;
 214   nat44_is_idle_session_ctx_t ctx;
 215
 216   if (PREDICT_FALSE
 217       (nat44_ed_maximum_sessions_exceeded (sm, rx_fib_index, thread_index)))
 218     {
 219       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 220       nat_elog_notice ("maximum sessions exceeded");
 221       return 0;
 222     }
 223
 224   s = nat_ed_session_alloc (sm, thread_index, now, nat_proto);
 225   if (!s)
 226     {
 227       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_USER_SESS_EXCEEDED];
 228       nat_elog_warn ("create NAT session failed");
 229       return 0;
 230     }
 231
 232   ip = vlib_buffer_get_current (b);
 233   udp = ip4_next_header (ip);
 234
 235   s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 236   s->ext_host_port = nat_proto == NAT_PROTOCOL_ICMP ? 0 : udp->src_port;
 237   s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 238   if (lb_nat)
 239     s->flags |= SNAT_SESSION_FLAG_LOAD_BALANCING;
 240   if (lb_nat == AFFINITY_LB_NAT)
 241     s->flags |= SNAT_SESSION_FLAG_AFFINITY;
 242   s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 243   s->out2in.addr = o2i_addr;
 244   s->out2in.port = o2i_port;
 245   s->out2in.fib_index = o2i_fib_index;
 246   s->in2out.addr = i2o_addr;
 247   s->in2out.port = i2o_port;
 248   s->in2out.fib_index = i2o_fib_index;
 249   s->nat_proto = nat_proto;
 250
 251   /* Add to lookup tables */
 252   init_ed_kv (&kv, o2i_addr, o2i_port, s->ext_host_addr, s->ext_host_port,
 253               o2i_fib_index, ip->protocol, thread_index, s - tsm->sessions);
 254   ctx.now = now;
 255   ctx.thread_index = thread_index;
 256   if (clib_bihash_add_or_overwrite_stale_16_8 (&sm->out2in_ed, &kv,
 257                                                nat44_o2i_ed_is_idle_session_cb,
 258                                                &ctx))
 259     nat_elog_notice ("out2in-ed key add failed");
 260
 261   if (twice_nat == TWICE_NAT || (twice_nat == TWICE_NAT_SELF &&
 262                                  ip->src_address.as_u32 == i2o_addr.as_u32))
 263     {
 264       if (snat_alloc_outside_address_and_port (sm->twice_nat_addresses, 0,
 265                                                thread_index,
 266                                                nat_proto,
 267                                                &s->ext_host_nat_addr,
 268                                                &s->ext_host_nat_port,
 269                                                sm->port_per_thread,
 270                                                tsm->snat_thread_index))
 271         {
 272           b->error = node->errors[NAT_OUT2IN_ED_ERROR_OUT_OF_PORTS];
 273           nat_ed_session_delete (sm, s, thread_index, 1);
 274           if (clib_bihash_add_del_16_8 (&sm->out2in_ed, &kv, 0))
 275             nat_elog_notice ("out2in-ed key del failed");
 276           return 0;
 277         }
 278       s->flags |= SNAT_SESSION_FLAG_TWICE_NAT;
 279       init_ed_kv (&kv, i2o_addr, i2o_port, s->ext_host_nat_addr,
 280                   s->ext_host_nat_port, i2o_fib_index, ip->protocol,
 281                   thread_index, s - tsm->sessions);
 282     }
 283   else
 284     {
 285       init_ed_kv (&kv, i2o_addr, i2o_port, s->ext_host_addr,
 286                   s->ext_host_port, i2o_fib_index, ip->protocol,
 287                   thread_index, s - tsm->sessions);
 288     }
 289   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->in2out_ed, &kv,
 290                                                nat44_i2o_ed_is_idle_session_cb,
 291                                                &ctx))
 292     nat_elog_notice ("in2out-ed key add failed");
 293
 294   snat_ipfix_logging_nat44_ses_create (thread_index,
 295                                        s->in2out.addr.as_u32,
 296                                        s->out2in.addr.as_u32,
 297                                        s->nat_proto,
 298                                        s->in2out.port,
 299                                        s->out2in.port, s->in2out.fib_index);
 300
 301   nat_syslog_nat44_sadd (s->user_index, s->in2out.fib_index,
 302                          &s->in2out.addr, s->in2out.port,
 303                          &s->ext_host_nat_addr, s->ext_host_nat_port,
 304                          &s->out2in.addr, s->out2in.port,
 305                          &s->ext_host_addr, s->ext_host_port,
 306                          s->nat_proto, is_twice_nat_session (s));
 307
 308   nat_ha_sadd (&s->in2out.addr, s->in2out.port, &s->out2in.addr,
 309                s->out2in.port, &s->ext_host_addr, s->ext_host_port,
 310                &s->ext_host_nat_addr, s->ext_host_nat_port,
 311                s->nat_proto, s->in2out.fib_index, s->flags, thread_index, 0);
 312
 313   return s;
 314 }
 315
 316 static int
 317 next_src_nat (snat_main_t * sm, ip4_header_t * ip, u16 src_port,
 318               u16 dst_port, u32 thread_index, u32 rx_fib_index)
 319 {
 320   clib_bihash_kv_16_8_t kv, value;
 321   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 322
 323   init_ed_k (&kv, ip->src_address, src_port, ip->dst_address, dst_port,
 324              rx_fib_index, ip->protocol);
 325   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 326     return 1;
 327
 328   return 0;
 329 }
 330
 331 static void
 332 create_bypass_for_fwd (snat_main_t * sm, vlib_buffer_t * b, ip4_header_t * ip,
 333                        u32 rx_fib_index, u32 thread_index)
 334 {
 335   clib_bihash_kv_16_8_t kv, value;
 336   udp_header_t *udp;
 337   snat_session_t *s = 0;
 338   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 339   vlib_main_t *vm = vlib_get_main ();
 340   f64 now = vlib_time_now (vm);
 341   u16 l_port, r_port;
 342
 343   if (ip->protocol == IP_PROTOCOL_ICMP)
 344     {
 345       if (get_icmp_o2i_ed_key
 346           (b, ip, rx_fib_index, ~0, ~0, 0, &l_port, &r_port, &kv))
 347         return;
 348     }
 349   else
 350     {
 351       if (ip->protocol == IP_PROTOCOL_UDP || ip->protocol == IP_PROTOCOL_TCP)
 352         {
 353           udp = ip4_next_header (ip);
 354           l_port = udp->dst_port;
 355           r_port = udp->src_port;
 356         }
 357       else
 358         {
 359           l_port = 0;
 360           r_port = 0;
 361         }
 362       init_ed_k (&kv, ip->dst_address, l_port, ip->src_address, r_port,
 363                  rx_fib_index, ip->protocol);
 364     }
 365
 366   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 367     {
 368       ASSERT (thread_index == ed_value_get_thread_index (&value));
 369       s =
 370         pool_elt_at_index (tsm->sessions,
 371                            ed_value_get_session_index (&value));
 372     }
 373   else
 374     {
 375       u32 proto;
 376
 377       if (PREDICT_FALSE
 378           (nat44_ed_maximum_sessions_exceeded
 379            (sm, rx_fib_index, thread_index)))
 380         return;
 381
 382       s = nat_ed_session_alloc (sm, thread_index, now, ip->protocol);
 383       if (!s)
 384         {
 385           nat_elog_warn ("create NAT session failed");
 386           return;
 387         }
 388
 389       proto = ip_proto_to_nat_proto (ip->protocol);
 390
 391       s->ext_host_addr = ip->src_address;
 392       s->ext_host_port = r_port;
 393       s->flags |= SNAT_SESSION_FLAG_FWD_BYPASS;
 394       s->out2in.addr = ip->dst_address;
 395       s->out2in.port = l_port;
 396       s->nat_proto = proto;
 397       if (proto == NAT_PROTOCOL_OTHER)
 398         {
 399           s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 400           s->out2in.port = ip->protocol;
 401         }
 402       s->out2in.fib_index = 0;
 403       s->in2out.addr = s->out2in.addr;
 404       s->in2out.port = s->out2in.port;
 405       s->in2out.fib_index = s->out2in.fib_index;
 406
 407       kv.value = s - tsm->sessions;
 408       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &kv, 1))
 409         nat_elog_notice ("in2out_ed key add failed");
 410     }
 411
 412   if (ip->protocol == IP_PROTOCOL_TCP)
 413     {
 414       tcp_header_t *tcp = ip4_next_header (ip);
 415       if (nat44_set_tcp_session_state_o2i
 416           (sm, now, s, tcp->flags, tcp->ack_number, tcp->seq_number,
 417            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,
 443                       ip4_header_t * ip, ip4_address_t * addr,
 444                       u16 * port, u32 * fib_index, nat_protocol_t * proto,
 445                       void *d, void *e, u8 * dont_translate)
 446 {
 447   u32 next = ~0, sw_if_index, rx_fib_index;
 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 is_addr_only, identity_nat;
 452   u16 l_port, r_port;
 453   vlib_main_t *vm = vlib_get_main ();
 454   ip4_address_t sm_addr;
 455   u16 sm_port;
 456   u32 sm_fib_index;
 457   *dont_translate = 0;
 458
 459   sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
 460   rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 461
 462   if (get_icmp_o2i_ed_key
 463       (b, ip, rx_fib_index, ~0, ~0, proto, &l_port, &r_port, &kv))
 464     {
 465       b->error = node->errors[NAT_OUT2IN_ED_ERROR_UNSUPPORTED_PROTOCOL];
 466       next = NAT_NEXT_DROP;
 467       goto out;
 468     }
 469
 470   if (clib_bihash_search_16_8 (&sm->out2in_ed, &kv, &value))
 471     {
 472       /* Try to match static mapping */
 473       if (snat_static_mapping_match
 474           (sm, ip->dst_address, l_port, rx_fib_index,
 475            ip_proto_to_nat_proto (ip->protocol), &sm_addr, &sm_port,
 476            &sm_fib_index, 1, &is_addr_only, 0, 0, 0, &identity_nat))
 477         {
 478           if (!sm->forwarding_enabled)
 479             {
 480               /* Don't NAT packet aimed at the intfc address */
 481               if (PREDICT_FALSE (is_interface_addr (sm, node, sw_if_index,
 482                                                     ip->dst_address.as_u32)))
 483                 {
 484                   *dont_translate = 1;
 485                   goto out;
 486                 }
 487               b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 488               next = NAT_NEXT_DROP;
 489               goto out;
 490             }
 491           else
 492             {
 493               *dont_translate = 1;
 494               if (next_src_nat (sm, ip, l_port, r_port,
 495                                 thread_index, rx_fib_index))
 496                 {
 497                   next = NAT_NEXT_IN2OUT_ED_FAST_PATH;
 498                   goto out;
 499                 }
 500               if (sm->num_workers > 1)
 501                 create_bypass_for_fwd_worker (sm, b, ip, rx_fib_index);
 502               else
 503                 create_bypass_for_fwd (sm, b, ip, rx_fib_index, thread_index);
 504               goto out;
 505             }
 506         }
 507
 508       if (PREDICT_FALSE
 509           (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 510            ICMP4_echo_reply
 511            && (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 512                ICMP4_echo_request || !is_addr_only)))
 513         {
 514           b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 515           next = NAT_NEXT_DROP;
 516           goto out;
 517         }
 518
 519       if (PREDICT_FALSE (identity_nat))
 520         {
 521           *dont_translate = 1;
 522           goto out;
 523         }
 524
 525       /* Create session initiated by host from external network */
 526       s =
 527         create_session_for_static_mapping_ed (sm, b, sm_addr, sm_port,
 528                                               sm_fib_index, ip->dst_address,
 529                                               l_port, rx_fib_index, *proto,
 530                                               node, rx_fib_index,
 531                                               thread_index, 0, 0,
 532                                               vlib_time_now (vm));
 533
 534       if (!s)
 535         {
 536           next = NAT_NEXT_DROP;
 537           goto out;
 538         }
 539     }
 540   else
 541     {
 542       if (PREDICT_FALSE
 543           (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 544            ICMP4_echo_reply
 545            && vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 546            ICMP4_echo_request
 547            && !icmp_type_is_error_message (vnet_buffer (b)->ip.
 548                                            reass.icmp_type_or_tcp_flags)))
 549         {
 550           b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 551           next = NAT_NEXT_DROP;
 552           goto out;
 553         }
 554
 555       ASSERT (thread_index == ed_value_get_thread_index (&value));
 556       s =
 557         pool_elt_at_index (tsm->sessions,
 558                            ed_value_get_session_index (&value));
 559     }
 560 out:
 561   if (s)
 562     {
 563       *addr = s->in2out.addr;
 564       *port = s->in2out.port;
 565       *fib_index = s->in2out.fib_index;
 566     }
 567   if (d)
 568     *(snat_session_t **) d = s;
 569   return next;
 570 }
 571 #endif
 572
 573 static snat_session_t *
 574 nat44_ed_out2in_unknown_proto (snat_main_t * sm,
 575                                vlib_buffer_t * b,
 576                                ip4_header_t * ip,
 577                                u32 rx_fib_index,
 578                                u32 thread_index,
 579                                f64 now,
 580                                vlib_main_t * vm, vlib_node_runtime_t * node)
 581 {
 582   clib_bihash_kv_8_8_t kv, value;
 583   clib_bihash_kv_16_8_t s_kv, s_value;
 584   snat_static_mapping_t *m;
 585   u32 old_addr, new_addr;
 586   ip_csum_t sum;
 587   snat_session_t *s;
 588   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 589
 590   old_addr = ip->dst_address.as_u32;
 591
 592   init_ed_k (&s_kv, ip->dst_address, 0, ip->src_address, 0, rx_fib_index,
 593              ip->protocol);
 594
 595   if (!clib_bihash_search_16_8 (&sm->out2in_ed, &s_kv, &s_value))
 596     {
 597       ASSERT (thread_index == ed_value_get_thread_index (&s_value));
 598       s =
 599         pool_elt_at_index (tsm->sessions,
 600                            ed_value_get_session_index (&s_value));
 601       new_addr = ip->dst_address.as_u32 = s->in2out.addr.as_u32;
 602     }
 603   else
 604     {
 605       if (PREDICT_FALSE
 606           (nat44_ed_maximum_sessions_exceeded
 607            (sm, rx_fib_index, thread_index)))
 608         {
 609           b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 610           nat_elog_notice ("maximum sessions exceeded");
 611           return 0;
 612         }
 613
 614       init_nat_k (&kv, ip->dst_address, 0, 0, 0);
 615       if (clib_bihash_search_8_8
 616           (&sm->static_mapping_by_external, &kv, &value))
 617         {
 618           b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 619           return 0;
 620         }
 621
 622       m = pool_elt_at_index (sm->static_mappings, value.value);
 623
 624       new_addr = ip->dst_address.as_u32 = m->local_addr.as_u32;
 625
 626       /* Create a new session */
 627       s = nat_ed_session_alloc (sm, thread_index, now, ip->protocol);
 628       if (!s)
 629         {
 630           b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_USER_SESS_EXCEEDED];
 631           nat_elog_warn ("create NAT session failed");
 632           return 0;
 633         }
 634
 635       s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 636       s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 637       s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 638       s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 639       s->out2in.addr.as_u32 = old_addr;
 640       s->out2in.fib_index = rx_fib_index;
 641       s->in2out.addr.as_u32 = new_addr;
 642       s->in2out.fib_index = m->fib_index;
 643       s->in2out.port = s->out2in.port = ip->protocol;
 644
 645       /* Add to lookup tables */
 646       s_kv.value = s - tsm->sessions;
 647       if (clib_bihash_add_del_16_8 (&sm->out2in_ed, &s_kv, 1))
 648         nat_elog_notice ("out2in key add failed");
 649
 650       init_ed_kv (&s_kv, ip->dst_address, 0, ip->src_address, 0, m->fib_index,
 651                   ip->protocol, thread_index, s - tsm->sessions);
 652       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &s_kv, 1))
 653         nat_elog_notice ("in2out key add failed");
 654     }
 655
 656   /* Update IP checksum */
 657   sum = ip->checksum;
 658   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
 659   ip->checksum = ip_csum_fold (sum);
 660
 661   vnet_buffer (b)->sw_if_index[VLIB_TX] = s->in2out.fib_index;
 662
 663   /* Accounting */
 664   nat44_session_update_counters (s, now, vlib_buffer_length_in_chain (vm, b),
 665                                  thread_index);
 666   /* Per-user LRU list maintenance */
 667   nat44_session_update_lru (sm, s, thread_index);
 668
 669   return s;
 670 }
 671
 672 static inline uword
 673 nat44_ed_out2in_fast_path_node_fn_inline (vlib_main_t * vm,
 674                                           vlib_node_runtime_t * node,
 675                                           vlib_frame_t * frame,
 676                                           int is_multi_worker)
 677 {
 678   u32 n_left_from, *from, pkts_processed = 0, stats_node_index;
 679   snat_main_t *sm = &snat_main;
 680   f64 now = vlib_time_now (vm);
 681   u32 thread_index = vm->thread_index;
 682   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 683   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 684     0, fragments = 0;
 685
 686   stats_node_index = sm->ed_out2in_node_index;
 687
 688   from = vlib_frame_vector_args (frame);
 689   n_left_from = frame->n_vectors;
 690
 691   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b = bufs;
 692   u16 nexts[VLIB_FRAME_SIZE], *next = nexts;
 693   vlib_get_buffers (vm, from, b, n_left_from);
 694
 695   while (n_left_from > 0)
 696     {
 697       vlib_buffer_t *b0;
 698       u32 sw_if_index0, rx_fib_index0, proto0, old_addr0, new_addr0;
 699       u16 old_port0, new_port0;
 700       ip4_header_t *ip0;
 701       udp_header_t *udp0;
 702       tcp_header_t *tcp0;
 703       snat_session_t *s0 = 0;
 704       clib_bihash_kv_16_8_t kv0, value0;
 705       ip_csum_t sum0;
 706
 707       b0 = *b;
 708       next[0] = vnet_buffer2 (b0)->nat.arc_next;
 709
 710       vnet_buffer (b0)->snat.flags = 0;
 711       ip0 = vlib_buffer_get_current (b0);
 712
 713       sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 714       rx_fib_index0 =
 715         fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4, sw_if_index0);
 716
 717       if (PREDICT_FALSE (ip0->ttl == 1))
 718         {
 719           vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 720           icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 721                                        ICMP4_time_exceeded_ttl_exceeded_in_transit,
 722                                        0);
 723           next[0] = NAT_NEXT_ICMP_ERROR;
 724           goto trace0;
 725         }
 726
 727       udp0 = ip4_next_header (ip0);
 728       tcp0 = (tcp_header_t *) udp0;
 729       proto0 = ip_proto_to_nat_proto (ip0->protocol);
 730
 731       if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
 732         {
 733           next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 734           goto trace0;
 735         }
 736
 737       if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
 738         {
 739           next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 740           goto trace0;
 741         }
 742
 743       init_ed_k (&kv0, ip0->dst_address,
 744                  vnet_buffer (b0)->ip.reass.l4_dst_port, ip0->src_address,
 745                  vnet_buffer (b0)->ip.reass.l4_src_port, rx_fib_index0,
 746                  ip0->protocol);
 747
 748       /* there is a stashed index in vnet_buffer2 from handoff node,
 749        * see if we can use it */
 750       if (is_multi_worker
 751           &&
 752           PREDICT_TRUE (!pool_is_free_index
 753                         (tsm->sessions,
 754                          vnet_buffer2 (b0)->nat.ed_out2in_nat_session_index)))
 755         {
 756           s0 = pool_elt_at_index (tsm->sessions,
 757                                   vnet_buffer2 (b0)->
 758                                   nat.ed_out2in_nat_session_index);
 759           if (PREDICT_TRUE
 760               (s0->out2in.addr.as_u32 == ip0->dst_address.as_u32
 761                && s0->out2in.port == vnet_buffer (b0)->ip.reass.l4_dst_port
 762                && s0->nat_proto == ip_proto_to_nat_proto (ip0->protocol)
 763                && s0->out2in.fib_index == rx_fib_index0
 764                && s0->ext_host_addr.as_u32 == ip0->src_address.as_u32
 765                && s0->ext_host_port ==
 766                vnet_buffer (b0)->ip.reass.l4_src_port))
 767             {
 768               /* yes, this is the droid we're looking for */
 769               goto skip_lookup;
 770             }
 771         }
 772
 773       if (clib_bihash_search_16_8 (&sm->out2in_ed, &kv0, &value0))
 774         {
 775           next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 776           goto trace0;
 777         }
 778       ASSERT (thread_index == ed_value_get_thread_index (&value0));
 779       s0 =
 780         pool_elt_at_index (tsm->sessions,
 781                            ed_value_get_session_index (&value0));
 782
 783     skip_lookup:
 784       if (s0->tcp_closed_timestamp)
 785         {
 786           if (now >= s0->tcp_closed_timestamp)
 787             {
 788               // session is closed, go slow path
 789               next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 790             }
 791           else
 792             {
 793               // session in transitory timeout, drop
 794               b0->error = node->errors[NAT_OUT2IN_ED_ERROR_TCP_CLOSED];
 795               next[0] = NAT_NEXT_DROP;
 796             }
 797           goto trace0;
 798         }
 799
 800       // drop if session expired
 801       u64 sess_timeout_time;
 802       sess_timeout_time =
 803         s0->last_heard + (f64) nat44_session_get_timeout (sm, s0);
 804       if (now >= sess_timeout_time)
 805         {
 806           // session is closed, go slow path
 807           nat_free_session_data (sm, s0, thread_index, 0);
 808           nat_ed_session_delete (sm, s0, thread_index, 1);
 809           next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 810           goto trace0;
 811         }
 812       //
 813
 814       old_addr0 = ip0->dst_address.as_u32;
 815       new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
 816       vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
 817
 818       sum0 = ip0->checksum;
 819       sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 820                              dst_address);
 821       if (PREDICT_FALSE (is_twice_nat_session (s0)))
 822         sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 823                                s0->ext_host_nat_addr.as_u32, ip4_header_t,
 824                                src_address);
 825       ip0->checksum = ip_csum_fold (sum0);
 826
 827       old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
 828
 829       if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
 830         {
 831           if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 832             {
 833               new_port0 = udp0->dst_port = s0->in2out.port;
 834               sum0 = tcp0->checksum;
 835               sum0 =
 836                 ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 837                                 dst_address);
 838               sum0 =
 839                 ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 840                                 length);
 841               if (is_twice_nat_session (s0))
 842                 {
 843                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 844                                          s0->ext_host_nat_addr.as_u32,
 845                                          ip4_header_t, dst_address);
 846                   sum0 =
 847                     ip_csum_update (sum0,
 848                                     vnet_buffer (b0)->ip.reass.l4_src_port,
 849                                     s0->ext_host_nat_port, ip4_header_t,
 850                                     length);
 851                   tcp0->src_port = s0->ext_host_nat_port;
 852                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 853                 }
 854               tcp0->checksum = ip_csum_fold (sum0);
 855             }
 856           tcp_packets++;
 857           if (nat44_set_tcp_session_state_o2i
 858               (sm, now, s0,
 859                vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags,
 860                vnet_buffer (b0)->ip.reass.tcp_ack_number,
 861                vnet_buffer (b0)->ip.reass.tcp_seq_number, thread_index))
 862             goto trace0;
 863         }
 864       else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
 865                && udp0->checksum)
 866         {
 867           new_port0 = udp0->dst_port = s0->in2out.port;
 868           sum0 = udp0->checksum;
 869           sum0 =
 870             ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 871                             dst_address);
 872           sum0 =
 873             ip_csum_update (sum0, old_port0, new_port0, ip4_header_t, length);
 874           if (PREDICT_FALSE (is_twice_nat_session (s0)))
 875             {
 876               sum0 =
 877                 ip_csum_update (sum0, ip0->src_address.as_u32,
 878                                 s0->ext_host_nat_addr.as_u32, ip4_header_t,
 879                                 dst_address);
 880               sum0 =
 881                 ip_csum_update (sum0, vnet_buffer (b0)->ip.reass.l4_src_port,
 882                                 s0->ext_host_nat_port, ip4_header_t, length);
 883               udp0->src_port = s0->ext_host_nat_port;
 884               ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 885             }
 886           udp0->checksum = ip_csum_fold (sum0);
 887           udp_packets++;
 888         }
 889       else
 890         {
 891           if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 892             {
 893               new_port0 = udp0->dst_port = s0->in2out.port;
 894               if (PREDICT_FALSE (is_twice_nat_session (s0)))
 895                 {
 896                   udp0->src_port = s0->ext_host_nat_port;
 897                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 898                 }
 899             }
 900           udp_packets++;
 901         }
 902
 903       /* Accounting */
 904       nat44_session_update_counters (s0, now,
 905                                      vlib_buffer_length_in_chain (vm, b0),
 906                                      thread_index);
 907       /* Per-user LRU list maintenance */
 908       nat44_session_update_lru (sm, s0, thread_index);
 909
 910     trace0:
 911       if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 912                          && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 913         {
 914           nat44_ed_out2in_trace_t *t =
 915             vlib_add_trace (vm, node, b0, sizeof (*t));
 916           t->sw_if_index = sw_if_index0;
 917           t->next_index = next[0];
 918           t->is_slow_path = 0;
 919
 920           if (s0)
 921             t->session_index = s0 - tsm->sessions;
 922           else
 923             t->session_index = ~0;
 924         }
 925
 926       pkts_processed += next[0] == vnet_buffer2 (b0)->nat.arc_next;
 927
 928       n_left_from--;
 929       next++;
 930       b++;
 931     }
 932
 933   vlib_buffer_enqueue_to_next (vm, node, from, (u16 *) nexts,
 934                                frame->n_vectors);
 935
 936   vlib_node_increment_counter (vm, stats_node_index,
 937                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
 938                                pkts_processed);
 939   vlib_node_increment_counter (vm, stats_node_index,
 940                                NAT_OUT2IN_ED_ERROR_TCP_PACKETS, tcp_packets);
 941   vlib_node_increment_counter (vm, stats_node_index,
 942                                NAT_OUT2IN_ED_ERROR_UDP_PACKETS, udp_packets);
 943   vlib_node_increment_counter (vm, stats_node_index,
 944                                NAT_OUT2IN_ED_ERROR_ICMP_PACKETS,
 945                                icmp_packets);
 946   vlib_node_increment_counter (vm, stats_node_index,
 947                                NAT_OUT2IN_ED_ERROR_OTHER_PACKETS,
 948                                other_packets);
 949   vlib_node_increment_counter (vm, stats_node_index,
 950                                NAT_OUT2IN_ED_ERROR_FRAGMENTS, fragments);
 951   return frame->n_vectors;
 952 }
 953
 954 static inline uword
 955 nat44_ed_out2in_slow_path_node_fn_inline (vlib_main_t * vm,
 956                                           vlib_node_runtime_t * node,
 957                                           vlib_frame_t * frame)
 958 {
 959   u32 n_left_from, *from, pkts_processed = 0, stats_node_index;
 960   snat_main_t *sm = &snat_main;
 961   f64 now = vlib_time_now (vm);
 962   u32 thread_index = vm->thread_index;
 963   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 964   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 965     0, fragments = 0;
 966
 967   stats_node_index = sm->ed_out2in_slowpath_node_index;
 968
 969   from = vlib_frame_vector_args (frame);
 970   n_left_from = frame->n_vectors;
 971
 972   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b = bufs;
 973   u16 nexts[VLIB_FRAME_SIZE], *next = nexts;
 974   vlib_get_buffers (vm, from, b, n_left_from);
 975
 976   while (n_left_from > 0)
 977     {
 978       vlib_buffer_t *b0;
 979       u32 sw_if_index0, rx_fib_index0, proto0, old_addr0, new_addr0;
 980       u16 old_port0, new_port0;
 981       ip4_header_t *ip0;
 982       udp_header_t *udp0;
 983       tcp_header_t *tcp0;
 984       icmp46_header_t *icmp0;
 985       snat_session_t *s0 = 0;
 986       clib_bihash_kv_16_8_t kv0, value0;
 987       ip_csum_t sum0;
 988       lb_nat_type_t lb_nat0;
 989       twice_nat_type_t twice_nat0;
 990       u8 identity_nat0;
 991       ip4_address_t sm_addr;
 992       u16 sm_port;
 993       u32 sm_fib_index;
 994
 995       b0 = *b;
 996       next[0] = vnet_buffer2 (b0)->nat.arc_next;
 997
 998       vnet_buffer (b0)->snat.flags = 0;
 999       ip0 = vlib_buffer_get_current (b0);
1000
1001       sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1002       rx_fib_index0 =
1003         fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4, sw_if_index0);
1004
1005       if (PREDICT_FALSE (ip0->ttl == 1))
1006         {
1007           vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1008           icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1009                                        ICMP4_time_exceeded_ttl_exceeded_in_transit,
1010                                        0);
1011           next[0] = NAT_NEXT_ICMP_ERROR;
1012           goto trace0;
1013         }
1014
1015       udp0 = ip4_next_header (ip0);
1016       tcp0 = (tcp_header_t *) udp0;
1017       icmp0 = (icmp46_header_t *) udp0;
1018       proto0 = ip_proto_to_nat_proto (ip0->protocol);
1019
1020       if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
1021         {
1022           s0 =
1023             nat44_ed_out2in_unknown_proto (sm, b0, ip0, rx_fib_index0,
1024                                            thread_index, now, vm, node);
1025           if (!sm->forwarding_enabled)
1026             {
1027               if (!s0)
1028                 next[0] = NAT_NEXT_DROP;
1029             }
1030           other_packets++;
1031           goto trace0;
1032         }
1033
1034       if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
1035         {
1036           next[0] = icmp_out2in_ed_slow_path
1037             (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1038              next[0], now, thread_index, &s0);
1039           icmp_packets++;
1040           goto trace0;
1041         }
1042
1043       init_ed_k (&kv0, ip0->dst_address,
1044                  vnet_buffer (b0)->ip.reass.l4_dst_port, ip0->src_address,
1045                  vnet_buffer (b0)->ip.reass.l4_src_port, rx_fib_index0,
1046                  ip0->protocol);
1047
1048       s0 = NULL;
1049       if (!clib_bihash_search_16_8 (&sm->out2in_ed, &kv0, &value0))
1050         {
1051           ASSERT (thread_index == ed_value_get_thread_index (&value0));
1052           s0 =
1053             pool_elt_at_index (tsm->sessions,
1054                                ed_value_get_session_index (&value0));
1055
1056           if (s0->tcp_closed_timestamp && now >= s0->tcp_closed_timestamp)
1057             {
1058               nat_free_session_data (sm, s0, thread_index, 0);
1059               nat_ed_session_delete (sm, s0, thread_index, 1);
1060               s0 = NULL;
1061             }
1062         }
1063
1064       if (!s0)
1065         {
1066           /* Try to match static mapping by external address and port,
1067              destination address and port in packet */
1068
1069           if (snat_static_mapping_match
1070               (sm, ip0->dst_address,
1071                vnet_buffer (b0)->ip.reass.l4_dst_port, rx_fib_index0,
1072                proto0, &sm_addr, &sm_port, &sm_fib_index, 1, 0,
1073                &twice_nat0, &lb_nat0, &ip0->src_address, &identity_nat0))
1074             {
1075               /*
1076                * Send DHCP packets to the ipv4 stack, or we won't
1077                * be able to use dhcp client on the outside interface
1078                */
1079               if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_UDP
1080                                  && (vnet_buffer (b0)->ip.reass.l4_dst_port ==
1081                                      clib_host_to_net_u16
1082                                      (UDP_DST_PORT_dhcp_to_client))))
1083                 {
1084                   goto trace0;
1085                 }
1086
1087               if (!sm->forwarding_enabled)
1088                 {
1089                   b0->error =
1090                     node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
1091                   next[0] = NAT_NEXT_DROP;
1092                 }
1093               else
1094                 {
1095                   if (next_src_nat
1096                       (sm, ip0, vnet_buffer (b0)->ip.reass.l4_src_port,
1097                        vnet_buffer (b0)->ip.reass.l4_dst_port,
1098                        thread_index, rx_fib_index0))
1099                     {
1100                       next[0] = NAT_NEXT_IN2OUT_ED_FAST_PATH;
1101                       goto trace0;
1102                     }
1103                   if (sm->num_workers > 1)
1104                     create_bypass_for_fwd_worker (sm, b0, ip0, rx_fib_index0);
1105                   else
1106                     create_bypass_for_fwd (sm, b0, ip0, rx_fib_index0,
1107                                            thread_index);
1108                 }
1109               goto trace0;
1110             }
1111
1112           if (PREDICT_FALSE (identity_nat0))
1113             goto trace0;
1114
1115           if ((proto0 == NAT_PROTOCOL_TCP)
1116               && !tcp_flags_is_init (vnet_buffer (b0)->ip.
1117                                      reass.icmp_type_or_tcp_flags))
1118             {
1119               b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
1120               next[0] = NAT_NEXT_DROP;
1121               goto trace0;
1122             }
1123
1124           /* Create session initiated by host from external network */
1125           s0 = create_session_for_static_mapping_ed (sm, b0,
1126                                                      sm_addr, sm_port,
1127                                                      sm_fib_index,
1128                                                      ip0->dst_address,
1129                                                      vnet_buffer (b0)->
1130                                                      ip.reass.l4_dst_port,
1131                                                      rx_fib_index0, proto0,
1132                                                      node, rx_fib_index0,
1133                                                      thread_index, twice_nat0,
1134                                                      lb_nat0, now);
1135           if (!s0)
1136             {
1137               next[0] = NAT_NEXT_DROP;
1138               goto trace0;
1139             }
1140         }
1141
1142       old_addr0 = ip0->dst_address.as_u32;
1143       new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
1144       vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
1145
1146       sum0 = ip0->checksum;
1147       sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1148                              dst_address);
1149       if (PREDICT_FALSE (is_twice_nat_session (s0)))
1150         sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1151                                s0->ext_host_nat_addr.as_u32, ip4_header_t,
1152                                src_address);
1153       ip0->checksum = ip_csum_fold (sum0);
1154
1155       old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
1156
1157       if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
1158         {
1159           if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1160             {
1161               new_port0 = udp0->dst_port = s0->in2out.port;
1162               sum0 = tcp0->checksum;
1163               sum0 =
1164                 ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1165                                 dst_address);
1166               sum0 =
1167                 ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1168                                 length);
1169               if (is_twice_nat_session (s0))
1170                 {
1171                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1172                                          s0->ext_host_nat_addr.as_u32,
1173                                          ip4_header_t, dst_address);
1174                   sum0 =
1175                     ip_csum_update (sum0,
1176                                     vnet_buffer (b0)->ip.reass.l4_src_port,
1177                                     s0->ext_host_nat_port, ip4_header_t,
1178                                     length);
1179                   tcp0->src_port = s0->ext_host_nat_port;
1180                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1181                 }
1182               tcp0->checksum = ip_csum_fold (sum0);
1183             }
1184           tcp_packets++;
1185           if (nat44_set_tcp_session_state_o2i
1186               (sm, now, s0,
1187                vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags,
1188                vnet_buffer (b0)->ip.reass.tcp_ack_number,
1189                vnet_buffer (b0)->ip.reass.tcp_seq_number, thread_index))
1190             goto trace0;
1191         }
1192       else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
1193                && udp0->checksum)
1194         {
1195           new_port0 = udp0->dst_port = s0->in2out.port;
1196           sum0 = udp0->checksum;
1197           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1198                                  dst_address);
1199           sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1200                                  length);
1201           if (PREDICT_FALSE (is_twice_nat_session (s0)))
1202             {
1203               sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1204                                      s0->ext_host_nat_addr.as_u32,
1205                                      ip4_header_t, dst_address);
1206               sum0 =
1207                 ip_csum_update (sum0,
1208                                 vnet_buffer (b0)->ip.reass.l4_src_port,
1209                                 s0->ext_host_nat_port, ip4_header_t, length);
1210               udp0->src_port = s0->ext_host_nat_port;
1211               ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1212             }
1213           udp0->checksum = ip_csum_fold (sum0);
1214           udp_packets++;
1215         }
1216       else
1217         {
1218           if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1219             {
1220               new_port0 = udp0->dst_port = s0->in2out.port;
1221               if (PREDICT_FALSE (is_twice_nat_session (s0)))
1222                 {
1223                   udp0->src_port = s0->ext_host_nat_port;
1224                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1225                 }
1226             }
1227           udp_packets++;
1228         }
1229
1230       /* Accounting */
1231       nat44_session_update_counters (s0, now,
1232                                      vlib_buffer_length_in_chain (vm, b0),
1233                                      thread_index);
1234       /* Per-user LRU list maintenance */
1235       nat44_session_update_lru (sm, s0, thread_index);
1236
1237     trace0:
1238       if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1239                          && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1240         {
1241           nat44_ed_out2in_trace_t *t =
1242             vlib_add_trace (vm, node, b0, sizeof (*t));
1243           t->sw_if_index = sw_if_index0;
1244           t->next_index = next[0];
1245           t->is_slow_path = 1;
1246
1247           if (s0)
1248             t->session_index = s0 - tsm->sessions;
1249           else
1250             t->session_index = ~0;
1251         }
1252
1253       pkts_processed += next[0] == vnet_buffer2 (b0)->nat.arc_next;
1254
1255       n_left_from--;
1256       next++;
1257       b++;
1258     }
1259
1260   vlib_buffer_enqueue_to_next (vm, node, from, (u16 *) nexts,
1261                                frame->n_vectors);
1262
1263   vlib_node_increment_counter (vm, stats_node_index,
1264                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
1265                                pkts_processed);
1266   vlib_node_increment_counter (vm, stats_node_index,
1267                                NAT_OUT2IN_ED_ERROR_TCP_PACKETS, tcp_packets);
1268   vlib_node_increment_counter (vm, stats_node_index,
1269                                NAT_OUT2IN_ED_ERROR_UDP_PACKETS, udp_packets);
1270   vlib_node_increment_counter (vm, stats_node_index,
1271                                NAT_OUT2IN_ED_ERROR_ICMP_PACKETS,
1272                                icmp_packets);
1273   vlib_node_increment_counter (vm, stats_node_index,
1274                                NAT_OUT2IN_ED_ERROR_OTHER_PACKETS,
1275                                other_packets);
1276   vlib_node_increment_counter (vm, stats_node_index,
1277                                NAT_OUT2IN_ED_ERROR_FRAGMENTS, fragments);
1278   return frame->n_vectors;
1279 }
1280
1281 VLIB_NODE_FN (nat44_ed_out2in_node) (vlib_main_t * vm,
1282                                      vlib_node_runtime_t * node,
1283                                      vlib_frame_t * frame)
1284 {
1285   if (snat_main.num_workers > 1)
1286     {
1287       return nat44_ed_out2in_fast_path_node_fn_inline (vm, node, frame, 1);
1288     }
1289   else
1290     {
1291       return nat44_ed_out2in_fast_path_node_fn_inline (vm, node, frame, 0);
1292     }
1293 }
1294
1295 /* *INDENT-OFF* */
1296 VLIB_REGISTER_NODE (nat44_ed_out2in_node) = {
1297   .name = "nat44-ed-out2in",
1298   .vector_size = sizeof (u32),
1299   .sibling_of = "nat-default",
1300   .format_trace = format_nat44_ed_out2in_trace,
1301   .type = VLIB_NODE_TYPE_INTERNAL,
1302   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1303   .error_strings = nat_out2in_ed_error_strings,
1304   .runtime_data_bytes = sizeof (snat_runtime_t),
1305 };
1306 /* *INDENT-ON* */
1307
1308 VLIB_NODE_FN (nat44_ed_out2in_slowpath_node) (vlib_main_t * vm,
1309                                               vlib_node_runtime_t * node,
1310                                               vlib_frame_t * frame)
1311 {
1312   return nat44_ed_out2in_slow_path_node_fn_inline (vm, node, frame);
1313 }
1314
1315 /* *INDENT-OFF* */
1316 VLIB_REGISTER_NODE (nat44_ed_out2in_slowpath_node) = {
1317   .name = "nat44-ed-out2in-slowpath",
1318   .vector_size = sizeof (u32),
1319   .sibling_of = "nat-default",
1320   .format_trace = format_nat44_ed_out2in_trace,
1321   .type = VLIB_NODE_TYPE_INTERNAL,
1322   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1323   .error_strings = nat_out2in_ed_error_strings,
1324   .runtime_data_bytes = sizeof (snat_runtime_t),
1325 };
1326 /* *INDENT-ON* */
1327
1328 static u8 *
1329 format_nat_pre_trace (u8 * s, va_list * args)
1330 {
1331   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1332   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1333   nat_pre_trace_t *t = va_arg (*args, nat_pre_trace_t *);
1334   return format (s, "out2in next_index %d arc_next_index %d", t->next_index,
1335                  t->arc_next_index);
1336 }
1337
1338 VLIB_NODE_FN (nat_pre_out2in_node) (vlib_main_t * vm,
1339                                     vlib_node_runtime_t * node,
1340                                     vlib_frame_t * frame)
1341 {
1342   return nat_pre_node_fn_inline (vm, node, frame,
1343                                  NAT_NEXT_OUT2IN_ED_FAST_PATH);
1344 }
1345
1346 /* *INDENT-OFF* */
1347 VLIB_REGISTER_NODE (nat_pre_out2in_node) = {
1348   .name = "nat-pre-out2in",
1349   .vector_size = sizeof (u32),
1350   .sibling_of = "nat-default",
1351   .format_trace = format_nat_pre_trace,
1352   .type = VLIB_NODE_TYPE_INTERNAL,
1353   .n_errors = 0,
1354  };
1355 /* *INDENT-ON* */
1356
1357 /*
1358  * fd.io coding-style-patch-verification: ON
1359  *
1360  * Local Variables:
1361  * eval: (c-set-style "gnu")
1362  * End:
1363  */