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, *to_next, pkts_processed = 0, stats_node_index;
 679   nat_next_t next_index;
 680   snat_main_t *sm = &snat_main;
 681   f64 now = vlib_time_now (vm);
 682   u32 thread_index = vm->thread_index;
 683   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 684   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 685     0, fragments = 0;
 686
 687   stats_node_index = sm->ed_out2in_node_index;
 688
 689   from = vlib_frame_vector_args (frame);
 690   n_left_from = frame->n_vectors;
 691   next_index = node->cached_next_index;
 692
 693   while (n_left_from > 0)
 694     {
 695       u32 n_left_to_next;
 696
 697       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 698
 699       while (n_left_from > 0 && n_left_to_next > 0)
 700         {
 701           u32 bi0;
 702           vlib_buffer_t *b0;
 703           u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
 704             new_addr0;
 705           u16 old_port0, new_port0;
 706           ip4_header_t *ip0;
 707           udp_header_t *udp0;
 708           tcp_header_t *tcp0;
 709           snat_session_t *s0 = 0;
 710           clib_bihash_kv_16_8_t kv0, value0;
 711           ip_csum_t sum0;
 712
 713           /* speculatively enqueue b0 to the current next frame */
 714           bi0 = from[0];
 715           to_next[0] = bi0;
 716           from += 1;
 717           to_next += 1;
 718           n_left_from -= 1;
 719           n_left_to_next -= 1;
 720
 721           b0 = vlib_get_buffer (vm, bi0);
 722           next0 = vnet_buffer2 (b0)->nat.arc_next;
 723
 724           vnet_buffer (b0)->snat.flags = 0;
 725           ip0 = vlib_buffer_get_current (b0);
 726
 727           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 728           rx_fib_index0 =
 729             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 730                                                  sw_if_index0);
 731
 732           if (PREDICT_FALSE (ip0->ttl == 1))
 733             {
 734               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 735               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 736                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 737                                            0);
 738               next0 = NAT_NEXT_ICMP_ERROR;
 739               goto trace0;
 740             }
 741
 742           udp0 = ip4_next_header (ip0);
 743           tcp0 = (tcp_header_t *) udp0;
 744           proto0 = ip_proto_to_nat_proto (ip0->protocol);
 745
 746           if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
 747             {
 748               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 749               goto trace0;
 750             }
 751
 752           if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
 753             {
 754               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 755               goto trace0;
 756             }
 757
 758           init_ed_k (&kv0, ip0->dst_address,
 759                      vnet_buffer (b0)->ip.reass.l4_dst_port, ip0->src_address,
 760                      vnet_buffer (b0)->ip.reass.l4_src_port, rx_fib_index0,
 761                      ip0->protocol);
 762
 763           /* there is a stashed index in vnet_buffer2 from handoff node,
 764            * see if we can use it */
 765           if (is_multi_worker && PREDICT_TRUE
 766               (!pool_is_free_index
 767                (tsm->sessions,
 768                 vnet_buffer2 (b0)->nat.ed_out2in_nat_session_index)))
 769             {
 770               s0 = pool_elt_at_index (tsm->sessions,
 771                                       vnet_buffer2 (b0)->
 772                                       nat.ed_out2in_nat_session_index);
 773               if (PREDICT_TRUE
 774                   (s0->out2in.addr.as_u32 == ip0->dst_address.as_u32
 775                    && s0->out2in.port ==
 776                    vnet_buffer (b0)->ip.reass.l4_dst_port
 777                    && s0->nat_proto == ip_proto_to_nat_proto (ip0->protocol)
 778                    && s0->out2in.fib_index == rx_fib_index0
 779                    && s0->ext_host_addr.as_u32 == ip0->src_address.as_u32
 780                    && s0->ext_host_port ==
 781                    vnet_buffer (b0)->ip.reass.l4_src_port))
 782                 {
 783                   /* yes, this is the droid we're looking for */
 784                   goto skip_lookup;
 785                 }
 786             }
 787
 788           if (clib_bihash_search_16_8 (&sm->out2in_ed, &kv0, &value0))
 789             {
 790               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 791               goto trace0;
 792             }
 793           ASSERT (thread_index == ed_value_get_thread_index (&value0));
 794           s0 =
 795             pool_elt_at_index (tsm->sessions,
 796                                ed_value_get_session_index (&value0));
 797
 798         skip_lookup:
 799           if (s0->tcp_closed_timestamp)
 800             {
 801               if (now >= s0->tcp_closed_timestamp)
 802                 {
 803                   // session is closed, go slow path
 804                   next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 805                 }
 806               else
 807                 {
 808                   // session in transitory timeout, drop
 809                   b0->error = node->errors[NAT_OUT2IN_ED_ERROR_TCP_CLOSED];
 810                   next0 = NAT_NEXT_DROP;
 811                 }
 812               goto trace0;
 813             }
 814
 815           // drop if session expired
 816           u64 sess_timeout_time;
 817           sess_timeout_time = s0->last_heard +
 818             (f64) nat44_session_get_timeout (sm, s0);
 819           if (now >= sess_timeout_time)
 820             {
 821               // session is closed, go slow path
 822               nat_free_session_data (sm, s0, thread_index, 0);
 823               nat_ed_session_delete (sm, s0, thread_index, 1);
 824               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 825               goto trace0;
 826             }
 827           //
 828
 829           old_addr0 = ip0->dst_address.as_u32;
 830           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
 831           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
 832
 833           sum0 = ip0->checksum;
 834           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 835                                  dst_address);
 836           if (PREDICT_FALSE (is_twice_nat_session (s0)))
 837             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 838                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
 839                                    src_address);
 840           ip0->checksum = ip_csum_fold (sum0);
 841
 842           old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
 843
 844           if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
 845             {
 846               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 847                 {
 848                   new_port0 = udp0->dst_port = s0->in2out.port;
 849                   sum0 = tcp0->checksum;
 850                   sum0 =
 851                     ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 852                                     dst_address);
 853                   sum0 =
 854                     ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 855                                     length);
 856                   if (is_twice_nat_session (s0))
 857                     {
 858                       sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 859                                              s0->ext_host_nat_addr.as_u32,
 860                                              ip4_header_t, dst_address);
 861                       sum0 =
 862                         ip_csum_update (sum0,
 863                                         vnet_buffer (b0)->ip.
 864                                         reass.l4_src_port,
 865                                         s0->ext_host_nat_port, ip4_header_t,
 866                                         length);
 867                       tcp0->src_port = s0->ext_host_nat_port;
 868                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 869                     }
 870                   tcp0->checksum = ip_csum_fold (sum0);
 871                 }
 872               tcp_packets++;
 873               if (nat44_set_tcp_session_state_o2i
 874                   (sm, now, s0,
 875                    vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags,
 876                    vnet_buffer (b0)->ip.reass.tcp_ack_number,
 877                    vnet_buffer (b0)->ip.reass.tcp_seq_number, thread_index))
 878                 goto trace0;
 879             }
 880           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
 881                    && udp0->checksum)
 882             {
 883               new_port0 = udp0->dst_port = s0->in2out.port;
 884               sum0 = udp0->checksum;
 885               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 886                                      dst_address);
 887               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 888                                      length);
 889               if (PREDICT_FALSE (is_twice_nat_session (s0)))
 890                 {
 891                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 892                                          s0->ext_host_nat_addr.as_u32,
 893                                          ip4_header_t, dst_address);
 894                   sum0 =
 895                     ip_csum_update (sum0,
 896                                     vnet_buffer (b0)->ip.reass.l4_src_port,
 897                                     s0->ext_host_nat_port, ip4_header_t,
 898                                     length);
 899                   udp0->src_port = s0->ext_host_nat_port;
 900                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 901                 }
 902               udp0->checksum = ip_csum_fold (sum0);
 903               udp_packets++;
 904             }
 905           else
 906             {
 907               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 908                 {
 909                   new_port0 = udp0->dst_port = s0->in2out.port;
 910                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
 911                     {
 912                       udp0->src_port = s0->ext_host_nat_port;
 913                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 914                     }
 915                 }
 916               udp_packets++;
 917             }
 918
 919           /* Accounting */
 920           nat44_session_update_counters (s0, now,
 921                                          vlib_buffer_length_in_chain (vm, b0),
 922                                          thread_index);
 923           /* Per-user LRU list maintenance */
 924           nat44_session_update_lru (sm, s0, thread_index);
 925
 926         trace0:
 927           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 928                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 929             {
 930               nat44_ed_out2in_trace_t *t =
 931                 vlib_add_trace (vm, node, b0, sizeof (*t));
 932               t->sw_if_index = sw_if_index0;
 933               t->next_index = next0;
 934               t->is_slow_path = 0;
 935
 936               if (s0)
 937                 t->session_index = s0 - tsm->sessions;
 938               else
 939                 t->session_index = ~0;
 940             }
 941
 942           pkts_processed += next0 == vnet_buffer2 (b0)->nat.arc_next;
 943           /* verify speculative enqueue, maybe switch current next frame */
 944           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 945                                            to_next, n_left_to_next,
 946                                            bi0, next0);
 947         }
 948
 949       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 950     }
 951
 952   vlib_node_increment_counter (vm, stats_node_index,
 953                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
 954                                pkts_processed);
 955   vlib_node_increment_counter (vm, stats_node_index,
 956                                NAT_OUT2IN_ED_ERROR_TCP_PACKETS, tcp_packets);
 957   vlib_node_increment_counter (vm, stats_node_index,
 958                                NAT_OUT2IN_ED_ERROR_UDP_PACKETS, udp_packets);
 959   vlib_node_increment_counter (vm, stats_node_index,
 960                                NAT_OUT2IN_ED_ERROR_ICMP_PACKETS,
 961                                icmp_packets);
 962   vlib_node_increment_counter (vm, stats_node_index,
 963                                NAT_OUT2IN_ED_ERROR_OTHER_PACKETS,
 964                                other_packets);
 965   vlib_node_increment_counter (vm, stats_node_index,
 966                                NAT_OUT2IN_ED_ERROR_FRAGMENTS, fragments);
 967   return frame->n_vectors;
 968 }
 969
 970 static inline uword
 971 nat44_ed_out2in_slow_path_node_fn_inline (vlib_main_t * vm,
 972                                           vlib_node_runtime_t * node,
 973                                           vlib_frame_t * frame)
 974 {
 975   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
 976   nat_next_t next_index;
 977   snat_main_t *sm = &snat_main;
 978   f64 now = vlib_time_now (vm);
 979   u32 thread_index = vm->thread_index;
 980   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 981   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 982     0, fragments = 0;
 983
 984   stats_node_index = sm->ed_out2in_slowpath_node_index;
 985
 986   from = vlib_frame_vector_args (frame);
 987   n_left_from = frame->n_vectors;
 988   next_index = node->cached_next_index;
 989
 990   while (n_left_from > 0)
 991     {
 992       u32 n_left_to_next;
 993
 994       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 995
 996       while (n_left_from > 0 && n_left_to_next > 0)
 997         {
 998           u32 bi0;
 999           vlib_buffer_t *b0;
1000           u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
1001             new_addr0;
1002           u16 old_port0, new_port0;
1003           ip4_header_t *ip0;
1004           udp_header_t *udp0;
1005           tcp_header_t *tcp0;
1006           icmp46_header_t *icmp0;
1007           snat_session_t *s0 = 0;
1008           clib_bihash_kv_16_8_t kv0, value0;
1009           ip_csum_t sum0;
1010           lb_nat_type_t lb_nat0;
1011           twice_nat_type_t twice_nat0;
1012           u8 identity_nat0;
1013           ip4_address_t sm_addr;
1014           u16 sm_port;
1015           u32 sm_fib_index;
1016
1017           /* speculatively enqueue b0 to the current next frame */
1018           bi0 = from[0];
1019           to_next[0] = bi0;
1020           from += 1;
1021           to_next += 1;
1022           n_left_from -= 1;
1023           n_left_to_next -= 1;
1024
1025           b0 = vlib_get_buffer (vm, bi0);
1026           next0 = vnet_buffer2 (b0)->nat.arc_next;
1027
1028           vnet_buffer (b0)->snat.flags = 0;
1029           ip0 = vlib_buffer_get_current (b0);
1030
1031           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1032           rx_fib_index0 =
1033             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
1034                                                  sw_if_index0);
1035
1036           if (PREDICT_FALSE (ip0->ttl == 1))
1037             {
1038               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1039               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1040                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1041                                            0);
1042               next0 = NAT_NEXT_ICMP_ERROR;
1043               goto trace0;
1044             }
1045
1046           udp0 = ip4_next_header (ip0);
1047           tcp0 = (tcp_header_t *) udp0;
1048           icmp0 = (icmp46_header_t *) udp0;
1049           proto0 = ip_proto_to_nat_proto (ip0->protocol);
1050
1051           if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
1052             {
1053               s0 =
1054                 nat44_ed_out2in_unknown_proto (sm, b0, ip0, rx_fib_index0,
1055                                                thread_index, now, vm, node);
1056               if (!sm->forwarding_enabled)
1057                 {
1058                   if (!s0)
1059                     next0 = NAT_NEXT_DROP;
1060                 }
1061               other_packets++;
1062               goto trace0;
1063             }
1064
1065           if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
1066             {
1067               next0 = icmp_out2in_ed_slow_path
1068                 (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1069                  next0, now, thread_index, &s0);
1070               icmp_packets++;
1071               goto trace0;
1072             }
1073
1074           init_ed_k (&kv0, ip0->dst_address,
1075                      vnet_buffer (b0)->ip.reass.l4_dst_port, ip0->src_address,
1076                      vnet_buffer (b0)->ip.reass.l4_src_port, rx_fib_index0,
1077                      ip0->protocol);
1078
1079           s0 = NULL;
1080           if (!clib_bihash_search_16_8 (&sm->out2in_ed, &kv0, &value0))
1081             {
1082               ASSERT (thread_index == ed_value_get_thread_index (&value0));
1083               s0 =
1084                 pool_elt_at_index (tsm->sessions,
1085                                    ed_value_get_session_index (&value0));
1086
1087               if (s0->tcp_closed_timestamp && now >= s0->tcp_closed_timestamp)
1088                 {
1089                   nat_free_session_data (sm, s0, thread_index, 0);
1090                   nat_ed_session_delete (sm, s0, thread_index, 1);
1091                   s0 = NULL;
1092                 }
1093             }
1094
1095           if (!s0)
1096             {
1097               /* Try to match static mapping by external address and port,
1098                  destination address and port in packet */
1099
1100               if (snat_static_mapping_match
1101                   (sm, ip0->dst_address,
1102                    vnet_buffer (b0)->ip.reass.l4_dst_port, rx_fib_index0,
1103                    proto0, &sm_addr, &sm_port, &sm_fib_index, 1, 0,
1104                    &twice_nat0, &lb_nat0, &ip0->src_address, &identity_nat0))
1105                 {
1106                   /*
1107                    * Send DHCP packets to the ipv4 stack, or we won't
1108                    * be able to use dhcp client on the outside interface
1109                    */
1110                   if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_UDP
1111                                      && (vnet_buffer (b0)->ip.
1112                                          reass.l4_dst_port ==
1113                                          clib_host_to_net_u16
1114                                          (UDP_DST_PORT_dhcp_to_client))))
1115                     {
1116                       goto trace0;
1117                     }
1118
1119                   if (!sm->forwarding_enabled)
1120                     {
1121                       b0->error =
1122                         node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
1123                       next0 = NAT_NEXT_DROP;
1124                     }
1125                   else
1126                     {
1127                       if (next_src_nat
1128                           (sm, ip0, vnet_buffer (b0)->ip.reass.l4_src_port,
1129                            vnet_buffer (b0)->ip.reass.l4_dst_port,
1130                            thread_index, rx_fib_index0))
1131                         {
1132                           next0 = NAT_NEXT_IN2OUT_ED_FAST_PATH;
1133                           goto trace0;
1134                         }
1135                       if (sm->num_workers > 1)
1136                         create_bypass_for_fwd_worker (sm, b0, ip0,
1137                                                       rx_fib_index0);
1138                       else
1139                         create_bypass_for_fwd (sm, b0, ip0, rx_fib_index0,
1140                                                thread_index);
1141                     }
1142                   goto trace0;
1143                 }
1144
1145               if (PREDICT_FALSE (identity_nat0))
1146                 goto trace0;
1147
1148               if ((proto0 == NAT_PROTOCOL_TCP)
1149                   && !tcp_flags_is_init (vnet_buffer (b0)->ip.
1150                                          reass.icmp_type_or_tcp_flags))
1151                 {
1152                   b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
1153                   next0 = NAT_NEXT_DROP;
1154                   goto trace0;
1155                 }
1156
1157               /* Create session initiated by host from external network */
1158               s0 = create_session_for_static_mapping_ed (sm, b0,
1159                                                          sm_addr, sm_port,
1160                                                          sm_fib_index,
1161                                                          ip0->dst_address,
1162                                                          vnet_buffer (b0)->
1163                                                          ip.reass.l4_dst_port,
1164                                                          rx_fib_index0,
1165                                                          proto0, node,
1166                                                          rx_fib_index0,
1167                                                          thread_index,
1168                                                          twice_nat0, lb_nat0,
1169                                                          now);
1170               if (!s0)
1171                 {
1172                   next0 = NAT_NEXT_DROP;
1173                   goto trace0;
1174                 }
1175             }
1176
1177           old_addr0 = ip0->dst_address.as_u32;
1178           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
1179           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
1180
1181           sum0 = ip0->checksum;
1182           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1183                                  dst_address);
1184           if (PREDICT_FALSE (is_twice_nat_session (s0)))
1185             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1186                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
1187                                    src_address);
1188           ip0->checksum = ip_csum_fold (sum0);
1189
1190           old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
1191
1192           if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
1193             {
1194               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1195                 {
1196                   new_port0 = udp0->dst_port = s0->in2out.port;
1197                   sum0 = tcp0->checksum;
1198                   sum0 =
1199                     ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1200                                     dst_address);
1201                   sum0 =
1202                     ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1203                                     length);
1204                   if (is_twice_nat_session (s0))
1205                     {
1206                       sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1207                                              s0->ext_host_nat_addr.as_u32,
1208                                              ip4_header_t, dst_address);
1209                       sum0 =
1210                         ip_csum_update (sum0,
1211                                         vnet_buffer (b0)->ip.
1212                                         reass.l4_src_port,
1213                                         s0->ext_host_nat_port, ip4_header_t,
1214                                         length);
1215                       tcp0->src_port = s0->ext_host_nat_port;
1216                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1217                     }
1218                   tcp0->checksum = ip_csum_fold (sum0);
1219                 }
1220               tcp_packets++;
1221               if (nat44_set_tcp_session_state_o2i
1222                   (sm, now, s0,
1223                    vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags,
1224                    vnet_buffer (b0)->ip.reass.tcp_ack_number,
1225                    vnet_buffer (b0)->ip.reass.tcp_seq_number, thread_index))
1226                 goto trace0;
1227             }
1228           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
1229                    && udp0->checksum)
1230             {
1231               new_port0 = udp0->dst_port = s0->in2out.port;
1232               sum0 = udp0->checksum;
1233               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1234                                      dst_address);
1235               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1236                                      length);
1237               if (PREDICT_FALSE (is_twice_nat_session (s0)))
1238                 {
1239                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1240                                          s0->ext_host_nat_addr.as_u32,
1241                                          ip4_header_t, dst_address);
1242                   sum0 =
1243                     ip_csum_update (sum0,
1244                                     vnet_buffer (b0)->ip.reass.l4_src_port,
1245                                     s0->ext_host_nat_port, ip4_header_t,
1246                                     length);
1247                   udp0->src_port = s0->ext_host_nat_port;
1248                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1249                 }
1250               udp0->checksum = ip_csum_fold (sum0);
1251               udp_packets++;
1252             }
1253           else
1254             {
1255               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1256                 {
1257                   new_port0 = udp0->dst_port = s0->in2out.port;
1258                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
1259                     {
1260                       udp0->src_port = s0->ext_host_nat_port;
1261                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1262                     }
1263                 }
1264               udp_packets++;
1265             }
1266
1267           /* Accounting */
1268           nat44_session_update_counters (s0, now,
1269                                          vlib_buffer_length_in_chain (vm, b0),
1270                                          thread_index);
1271           /* Per-user LRU list maintenance */
1272           nat44_session_update_lru (sm, s0, thread_index);
1273
1274         trace0:
1275           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1276                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1277             {
1278               nat44_ed_out2in_trace_t *t =
1279                 vlib_add_trace (vm, node, b0, sizeof (*t));
1280               t->sw_if_index = sw_if_index0;
1281               t->next_index = next0;
1282               t->is_slow_path = 1;
1283
1284               if (s0)
1285                 t->session_index = s0 - tsm->sessions;
1286               else
1287                 t->session_index = ~0;
1288             }
1289
1290           pkts_processed += next0 == vnet_buffer2 (b0)->nat.arc_next;
1291           /* verify speculative enqueue, maybe switch current next frame */
1292           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1293                                            to_next, n_left_to_next,
1294                                            bi0, next0);
1295         }
1296
1297       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1298     }
1299
1300   vlib_node_increment_counter (vm, stats_node_index,
1301                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
1302                                pkts_processed);
1303   vlib_node_increment_counter (vm, stats_node_index,
1304                                NAT_OUT2IN_ED_ERROR_TCP_PACKETS, tcp_packets);
1305   vlib_node_increment_counter (vm, stats_node_index,
1306                                NAT_OUT2IN_ED_ERROR_UDP_PACKETS, udp_packets);
1307   vlib_node_increment_counter (vm, stats_node_index,
1308                                NAT_OUT2IN_ED_ERROR_ICMP_PACKETS,
1309                                icmp_packets);
1310   vlib_node_increment_counter (vm, stats_node_index,
1311                                NAT_OUT2IN_ED_ERROR_OTHER_PACKETS,
1312                                other_packets);
1313   vlib_node_increment_counter (vm, stats_node_index,
1314                                NAT_OUT2IN_ED_ERROR_FRAGMENTS, fragments);
1315   return frame->n_vectors;
1316 }
1317
1318 VLIB_NODE_FN (nat44_ed_out2in_node) (vlib_main_t * vm,
1319                                      vlib_node_runtime_t * node,
1320                                      vlib_frame_t * frame)
1321 {
1322   if (snat_main.num_workers > 1)
1323     {
1324       return nat44_ed_out2in_fast_path_node_fn_inline (vm, node, frame, 1);
1325     }
1326   else
1327     {
1328       return nat44_ed_out2in_fast_path_node_fn_inline (vm, node, frame, 0);
1329     }
1330 }
1331
1332 /* *INDENT-OFF* */
1333 VLIB_REGISTER_NODE (nat44_ed_out2in_node) = {
1334   .name = "nat44-ed-out2in",
1335   .vector_size = sizeof (u32),
1336   .sibling_of = "nat-default",
1337   .format_trace = format_nat44_ed_out2in_trace,
1338   .type = VLIB_NODE_TYPE_INTERNAL,
1339   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1340   .error_strings = nat_out2in_ed_error_strings,
1341   .runtime_data_bytes = sizeof (snat_runtime_t),
1342 };
1343 /* *INDENT-ON* */
1344
1345 VLIB_NODE_FN (nat44_ed_out2in_slowpath_node) (vlib_main_t * vm,
1346                                               vlib_node_runtime_t * node,
1347                                               vlib_frame_t * frame)
1348 {
1349   return nat44_ed_out2in_slow_path_node_fn_inline (vm, node, frame);
1350 }
1351
1352 /* *INDENT-OFF* */
1353 VLIB_REGISTER_NODE (nat44_ed_out2in_slowpath_node) = {
1354   .name = "nat44-ed-out2in-slowpath",
1355   .vector_size = sizeof (u32),
1356   .sibling_of = "nat-default",
1357   .format_trace = format_nat44_ed_out2in_trace,
1358   .type = VLIB_NODE_TYPE_INTERNAL,
1359   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1360   .error_strings = nat_out2in_ed_error_strings,
1361   .runtime_data_bytes = sizeof (snat_runtime_t),
1362 };
1363 /* *INDENT-ON* */
1364
1365 static u8 *
1366 format_nat_pre_trace (u8 * s, va_list * args)
1367 {
1368   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1369   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1370   nat_pre_trace_t *t = va_arg (*args, nat_pre_trace_t *);
1371   return format (s, "out2in next_index %d arc_next_index %d", t->next_index,
1372                  t->arc_next_index);
1373 }
1374
1375 VLIB_NODE_FN (nat_pre_out2in_node) (vlib_main_t * vm,
1376                                     vlib_node_runtime_t * node,
1377                                     vlib_frame_t * frame)
1378 {
1379   return nat_pre_node_fn_inline (vm, node, frame,
1380                                  NAT_NEXT_OUT2IN_ED_FAST_PATH);
1381 }
1382
1383 /* *INDENT-OFF* */
1384 VLIB_REGISTER_NODE (nat_pre_out2in_node) = {
1385   .name = "nat-pre-out2in",
1386   .vector_size = sizeof (u32),
1387   .sibling_of = "nat-default",
1388   .format_trace = format_nat_pre_trace,
1389   .type = VLIB_NODE_TYPE_INTERNAL,
1390   .n_errors = 0,
1391  };
1392 /* *INDENT-ON* */
1393
1394 /*
1395  * fd.io coding-style-patch-verification: ON
1396  *
1397  * Local Variables:
1398  * eval: (c-set-style "gnu")
1399  * End:
1400  */