src/plugins/nat/out2in_ed.c

   1 /*
   2  * Copyright (c) 2018 Cisco and/or its affiliates.
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15 /**
  16  * @file
  17  * @brief NAT44 endpoint-dependent outside to inside network translation
  18  */
  19
  20 #include <vlib/vlib.h>
  21 #include <vnet/vnet.h>
  22 #include <vnet/pg/pg.h>
  23 #include <vnet/ip/ip.h>
  24 #include <vnet/ethernet/ethernet.h>
  25 #include <vnet/fib/ip4_fib.h>
  26 #include <vnet/udp/udp.h>
  27 #include <vppinfra/error.h>
  28 #include <nat/nat.h>
  29 #include <nat/nat_ipfix_logging.h>
  30 #include <nat/nat_inlines.h>
  31 #include <nat/nat44_inlines.h>
  32 #include <nat/nat_syslog.h>
  33 #include <nat/nat_ha.h>
  34
  35 static char *nat_out2in_ed_error_strings[] = {
  36 #define _(sym,string) string,
  37   foreach_nat_out2in_ed_error
  38 #undef _
  39 };
  40
  41 typedef struct
  42 {
  43   u32 sw_if_index;
  44   u32 next_index;
  45   u32 session_index;
  46   u32 is_slow_path;
  47 } nat44_ed_out2in_trace_t;
  48
  49 static u8 *
  50 format_nat44_ed_out2in_trace (u8 * s, va_list * args)
  51 {
  52   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  53   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  54   nat44_ed_out2in_trace_t *t = va_arg (*args, nat44_ed_out2in_trace_t *);
  55   char *tag;
  56
  57   tag =
  58     t->is_slow_path ? "NAT44_OUT2IN_ED_SLOW_PATH" :
  59     "NAT44_OUT2IN_ED_FAST_PATH";
  60
  61   s = format (s, "%s: sw_if_index %d, next index %d, session %d", tag,
  62               t->sw_if_index, t->next_index, t->session_index);
  63
  64   return s;
  65 }
  66
  67 static inline u32
  68 icmp_out2in_ed_slow_path (snat_main_t * sm, vlib_buffer_t * b0,
  69                           ip4_header_t * ip0, icmp46_header_t * icmp0,
  70                           u32 sw_if_index0, u32 rx_fib_index0,
  71                           vlib_node_runtime_t * node, u32 next0, f64 now,
  72                           u32 thread_index, snat_session_t ** p_s0)
  73 {
  74   next0 = icmp_out2in (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
  75                        next0, thread_index, p_s0, 0);
  76   snat_session_t *s0 = *p_s0;
  77   if (PREDICT_TRUE (next0 != NAT_NEXT_DROP && s0))
  78     {
  79       /* Accounting */
  80       nat44_session_update_counters (s0, now,
  81                                      vlib_buffer_length_in_chain
  82                                      (sm->vlib_main, b0), thread_index);
  83       /* Per-user LRU list maintenance */
  84       nat44_session_update_lru (sm, s0, thread_index);
  85     }
  86   return next0;
  87 }
  88
  89 #ifndef CLIB_MARCH_VARIANT
  90 int
  91 nat44_o2i_ed_is_idle_session_cb (clib_bihash_kv_16_8_t * kv, void *arg)
  92 {
  93   snat_main_t *sm = &snat_main;
  94   nat44_is_idle_session_ctx_t *ctx = arg;
  95   snat_session_t *s;
  96   u64 sess_timeout_time;
  97   nat_ed_ses_key_t ed_key;
  98   clib_bihash_kv_16_8_t ed_kv;
  99   int i;
 100   snat_address_t *a;
 101   snat_session_key_t key;
 102   snat_main_per_thread_data_t *tsm = vec_elt_at_index (sm->per_thread_data,
 103                                                        ctx->thread_index);
 104
 105   s = pool_elt_at_index (tsm->sessions, kv->value);
 106   sess_timeout_time = s->last_heard + (f64) nat44_session_get_timeout (sm, s);
 107   if (ctx->now >= sess_timeout_time)
 108     {
 109       ed_key.l_addr = s->in2out.addr;
 110       ed_key.r_addr = s->ext_host_addr;
 111       ed_key.fib_index = s->in2out.fib_index;
 112       if (snat_is_unk_proto_session (s))
 113         {
 114           ed_key.proto = s->in2out.port;
 115           ed_key.r_port = 0;
 116           ed_key.l_port = 0;
 117         }
 118       else
 119         {
 120           ed_key.proto = snat_proto_to_ip_proto (s->in2out.protocol);
 121           ed_key.l_port = s->in2out.port;
 122           ed_key.r_port = s->ext_host_port;
 123         }
 124       if (is_twice_nat_session (s))
 125         {
 126           ed_key.r_addr = s->ext_host_nat_addr;
 127           ed_key.r_port = s->ext_host_nat_port;
 128         }
 129       ed_kv.key[0] = ed_key.as_u64[0];
 130       ed_kv.key[1] = ed_key.as_u64[1];
 131       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &ed_kv, 0))
 132         nat_elog_warn ("in2out_ed key del failed");
 133
 134       if (snat_is_unk_proto_session (s))
 135         goto delete;
 136
 137       snat_ipfix_logging_nat44_ses_delete (ctx->thread_index,
 138                                            s->in2out.addr.as_u32,
 139                                            s->out2in.addr.as_u32,
 140                                            s->in2out.protocol,
 141                                            s->in2out.port,
 142                                            s->out2in.port,
 143                                            s->in2out.fib_index);
 144
 145       nat_syslog_nat44_sdel (s->user_index, s->in2out.fib_index,
 146                              &s->in2out.addr, s->in2out.port,
 147                              &s->ext_host_nat_addr, s->ext_host_nat_port,
 148                              &s->out2in.addr, s->out2in.port,
 149                              &s->ext_host_addr, s->ext_host_port,
 150                              s->in2out.protocol, is_twice_nat_session (s));
 151
 152       nat_ha_sdel (&s->out2in.addr, s->out2in.port, &s->ext_host_addr,
 153                    s->ext_host_port, s->out2in.protocol, s->out2in.fib_index,
 154                    ctx->thread_index);
 155
 156       if (is_twice_nat_session (s))
 157         {
 158           for (i = 0; i < vec_len (sm->twice_nat_addresses); i++)
 159             {
 160               key.protocol = s->in2out.protocol;
 161               key.port = s->ext_host_nat_port;
 162               a = sm->twice_nat_addresses + i;
 163               if (a->addr.as_u32 == s->ext_host_nat_addr.as_u32)
 164                 {
 165                   snat_free_outside_address_and_port (sm->twice_nat_addresses,
 166                                                       ctx->thread_index,
 167                                                       &key);
 168                   break;
 169                 }
 170             }
 171         }
 172
 173       if (snat_is_session_static (s))
 174         goto delete;
 175
 176       snat_free_outside_address_and_port (sm->addresses, ctx->thread_index,
 177                                           &s->out2in);
 178     delete:
 179       nat44_delete_session (sm, s, ctx->thread_index);
 180       return 1;
 181     }
 182
 183   return 0;
 184 }
 185 #endif
 186
 187 static snat_session_t *
 188 create_session_for_static_mapping_ed (snat_main_t * sm,
 189                                       vlib_buffer_t * b,
 190                                       snat_session_key_t l_key,
 191                                       snat_session_key_t e_key,
 192                                       vlib_node_runtime_t * node,
 193                                       u32 thread_index,
 194                                       twice_nat_type_t twice_nat,
 195                                       lb_nat_type_t lb_nat, f64 now)
 196 {
 197   snat_session_t *s;
 198   snat_user_t *u;
 199   ip4_header_t *ip;
 200   udp_header_t *udp;
 201   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 202   clib_bihash_kv_16_8_t kv;
 203   snat_session_key_t eh_key;
 204   nat44_is_idle_session_ctx_t ctx;
 205
 206   nat44_session_try_cleanup (&l_key.addr, l_key.fib_index, thread_index, now);
 207
 208   if (PREDICT_FALSE (maximum_sessions_exceeded (sm, thread_index)))
 209     {
 210       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 211       nat_elog_notice ("maximum sessions exceeded");
 212       return 0;
 213     }
 214
 215   u = nat_user_get_or_create (sm, &l_key.addr, l_key.fib_index, thread_index);
 216   if (!u)
 217     {
 218       nat_elog_warn ("create NAT user failed");
 219       return 0;
 220     }
 221
 222   s = nat_ed_session_alloc (sm, u, thread_index, now);
 223   if (!s)
 224     {
 225       nat44_delete_user_with_no_session (sm, u, thread_index);
 226       nat_elog_warn ("create NAT session failed");
 227       return 0;
 228     }
 229
 230   ip = vlib_buffer_get_current (b);
 231   udp = ip4_next_header (ip);
 232
 233   s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 234   s->ext_host_port = e_key.protocol == SNAT_PROTOCOL_ICMP ? 0 : udp->src_port;
 235   s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 236   if (lb_nat)
 237     s->flags |= SNAT_SESSION_FLAG_LOAD_BALANCING;
 238   if (lb_nat == AFFINITY_LB_NAT)
 239     s->flags |= SNAT_SESSION_FLAG_AFFINITY;
 240   s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 241   s->out2in = e_key;
 242   s->in2out = l_key;
 243   s->in2out.protocol = s->out2in.protocol;
 244   user_session_increment (sm, u, 1);
 245
 246   /* Add to lookup tables */
 247   make_ed_kv (&kv, &e_key.addr, &s->ext_host_addr, ip->protocol,
 248               e_key.fib_index, e_key.port, s->ext_host_port);
 249   kv.value = s - tsm->sessions;
 250   ctx.now = now;
 251   ctx.thread_index = thread_index;
 252   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->out2in_ed, &kv,
 253                                                nat44_o2i_ed_is_idle_session_cb,
 254                                                &ctx))
 255     nat_elog_notice ("out2in-ed key add failed");
 256
 257   if (twice_nat == TWICE_NAT || (twice_nat == TWICE_NAT_SELF &&
 258                                  ip->src_address.as_u32 == l_key.addr.as_u32))
 259     {
 260       eh_key.protocol = e_key.protocol;
 261       if (snat_alloc_outside_address_and_port (sm->twice_nat_addresses, 0,
 262                                                thread_index, &eh_key,
 263                                                sm->port_per_thread,
 264                                                tsm->snat_thread_index))
 265         {
 266           b->error = node->errors[NAT_OUT2IN_ED_ERROR_OUT_OF_PORTS];
 267           nat44_delete_session (sm, s, thread_index);
 268           if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &kv, 0))
 269             nat_elog_notice ("out2in-ed key del failed");
 270           return 0;
 271         }
 272       s->ext_host_nat_addr.as_u32 = eh_key.addr.as_u32;
 273       s->ext_host_nat_port = eh_key.port;
 274       s->flags |= SNAT_SESSION_FLAG_TWICE_NAT;
 275       make_ed_kv (&kv, &l_key.addr, &s->ext_host_nat_addr, ip->protocol,
 276                   l_key.fib_index, l_key.port, s->ext_host_nat_port);
 277     }
 278   else
 279     {
 280       make_ed_kv (&kv, &l_key.addr, &s->ext_host_addr, ip->protocol,
 281                   l_key.fib_index, l_key.port, s->ext_host_port);
 282     }
 283   kv.value = s - tsm->sessions;
 284   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->in2out_ed, &kv,
 285                                                nat44_i2o_ed_is_idle_session_cb,
 286                                                &ctx))
 287     nat_elog_notice ("in2out-ed key add failed");
 288
 289   snat_ipfix_logging_nat44_ses_create (thread_index,
 290                                        s->in2out.addr.as_u32,
 291                                        s->out2in.addr.as_u32,
 292                                        s->in2out.protocol,
 293                                        s->in2out.port,
 294                                        s->out2in.port, s->in2out.fib_index);
 295
 296   nat_syslog_nat44_sadd (s->user_index, s->in2out.fib_index,
 297                          &s->in2out.addr, s->in2out.port,
 298                          &s->ext_host_nat_addr, s->ext_host_nat_port,
 299                          &s->out2in.addr, s->out2in.port,
 300                          &s->ext_host_addr, s->ext_host_port,
 301                          s->in2out.protocol, is_twice_nat_session (s));
 302
 303   nat_ha_sadd (&s->in2out.addr, s->in2out.port, &s->out2in.addr,
 304                s->out2in.port, &s->ext_host_addr, s->ext_host_port,
 305                &s->ext_host_nat_addr, s->ext_host_nat_port,
 306                s->in2out.protocol, s->in2out.fib_index, s->flags,
 307                thread_index, 0);
 308
 309   return s;
 310 }
 311
 312 static int
 313 next_src_nat (snat_main_t * sm, ip4_header_t * ip, u8 proto, u16 src_port,
 314               u16 dst_port, u32 thread_index, u32 rx_fib_index)
 315 {
 316   clib_bihash_kv_16_8_t kv, value;
 317   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 318
 319   make_ed_kv (&kv, &ip->src_address, &ip->dst_address, proto,
 320               rx_fib_index, src_port, dst_port);
 321   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 322     return 1;
 323
 324   return 0;
 325 }
 326
 327 static void
 328 create_bypass_for_fwd (snat_main_t * sm, vlib_buffer_t * b, ip4_header_t * ip,
 329                        u32 rx_fib_index, u32 thread_index)
 330 {
 331   nat_ed_ses_key_t key;
 332   clib_bihash_kv_16_8_t kv, value;
 333   udp_header_t *udp;
 334   snat_user_t *u;
 335   snat_session_t *s = 0;
 336   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 337   f64 now = vlib_time_now (sm->vlib_main);
 338
 339   if (ip->protocol == IP_PROTOCOL_ICMP)
 340     {
 341       if (get_icmp_o2i_ed_key (b, ip, &key))
 342         return;
 343     }
 344   else if (ip->protocol == IP_PROTOCOL_UDP || ip->protocol == IP_PROTOCOL_TCP)
 345     {
 346       udp = ip4_next_header (ip);
 347       key.r_addr = ip->src_address;
 348       key.l_addr = ip->dst_address;
 349       key.proto = ip->protocol;
 350       key.l_port = udp->dst_port;
 351       key.r_port = udp->src_port;
 352     }
 353   else
 354     {
 355       key.r_addr = ip->src_address;
 356       key.l_addr = ip->dst_address;
 357       key.proto = ip->protocol;
 358       key.l_port = key.r_port = 0;
 359     }
 360   key.fib_index = 0;
 361   kv.key[0] = key.as_u64[0];
 362   kv.key[1] = key.as_u64[1];
 363
 364   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 365     {
 366       s = pool_elt_at_index (tsm->sessions, value.value);
 367     }
 368   else
 369     {
 370       u32 proto;
 371
 372       if (PREDICT_FALSE (maximum_sessions_exceeded (sm, thread_index)))
 373         return;
 374
 375       u = nat_user_get_or_create (sm, &ip->dst_address, sm->inside_fib_index,
 376                                   thread_index);
 377       if (!u)
 378         {
 379           nat_elog_warn ("create NAT user failed");
 380           return;
 381         }
 382
 383       s = nat_ed_session_alloc (sm, u, thread_index, now);
 384       if (!s)
 385         {
 386           nat44_delete_user_with_no_session (sm, u, thread_index);
 387           nat_elog_warn ("create NAT session failed");
 388           return;
 389         }
 390
 391       proto = ip_proto_to_snat_proto (key.proto);
 392
 393       s->ext_host_addr = key.r_addr;
 394       s->ext_host_port = key.r_port;
 395       s->flags |= SNAT_SESSION_FLAG_FWD_BYPASS;
 396       s->out2in.addr = key.l_addr;
 397       s->out2in.port = key.l_port;
 398       s->out2in.protocol = proto;
 399       if (proto == ~0)
 400         {
 401           s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 402           s->out2in.port = ip->protocol;
 403         }
 404       s->out2in.fib_index = 0;
 405       s->in2out = s->out2in;
 406       user_session_increment (sm, u, 0);
 407
 408       kv.value = s - tsm->sessions;
 409       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &kv, 1))
 410         nat_elog_notice ("in2out_ed key add failed");
 411     }
 412
 413   if (ip->protocol == IP_PROTOCOL_TCP)
 414     {
 415       tcp_header_t *tcp = ip4_next_header (ip);
 416       if (nat44_set_tcp_session_state_o2i
 417           (sm, s, tcp->flags, tcp->ack_number, tcp->seq_number, thread_index))
 418         return;
 419     }
 420
 421   /* Accounting */
 422   nat44_session_update_counters (s, now, 0, thread_index);
 423   /* Per-user LRU list maintenance */
 424   nat44_session_update_lru (sm, s, thread_index);
 425 }
 426
 427 static inline void
 428 create_bypass_for_fwd_worker (snat_main_t * sm, vlib_buffer_t * b,
 429                               ip4_header_t * ip, u32 rx_fib_index)
 430 {
 431   ip4_header_t ip_wkr = {
 432     .src_address = ip->dst_address,
 433   };
 434   u32 thread_index = sm->worker_in2out_cb (&ip_wkr, rx_fib_index, 0);
 435
 436   create_bypass_for_fwd (sm, b, ip, rx_fib_index, thread_index);
 437 }
 438
 439 #ifndef CLIB_MARCH_VARIANT
 440 u32
 441 icmp_match_out2in_ed (snat_main_t * sm, vlib_node_runtime_t * node,
 442                       u32 thread_index, vlib_buffer_t * b, ip4_header_t * ip,
 443                       u8 * p_proto, snat_session_key_t * p_value,
 444                       u8 * p_dont_translate, void *d, void *e)
 445 {
 446   u32 next = ~0, sw_if_index, rx_fib_index;
 447   nat_ed_ses_key_t key;
 448   clib_bihash_kv_16_8_t kv, value;
 449   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 450   snat_session_t *s = 0;
 451   u8 dont_translate = 0, is_addr_only, identity_nat;
 452   snat_session_key_t e_key, l_key;
 453
 454   sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
 455   rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 456
 457   if (get_icmp_o2i_ed_key (b, ip, &key))
 458     {
 459       b->error = node->errors[NAT_OUT2IN_ED_ERROR_UNSUPPORTED_PROTOCOL];
 460       next = NAT_NEXT_DROP;
 461       goto out;
 462     }
 463   key.fib_index = rx_fib_index;
 464   kv.key[0] = key.as_u64[0];
 465   kv.key[1] = key.as_u64[1];
 466
 467   if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv, &value))
 468     {
 469       /* Try to match static mapping */
 470       e_key.addr = ip->dst_address;
 471       e_key.port = key.l_port;
 472       e_key.protocol = ip_proto_to_snat_proto (key.proto);
 473       e_key.fib_index = rx_fib_index;
 474       if (snat_static_mapping_match
 475           (sm, e_key, &l_key, 1, &is_addr_only, 0, 0, 0, &identity_nat))
 476         {
 477           if (!sm->forwarding_enabled)
 478             {
 479               /* Don't NAT packet aimed at the intfc address */
 480               if (PREDICT_FALSE (is_interface_addr (sm, node, sw_if_index,
 481                                                     ip->dst_address.as_u32)))
 482                 {
 483                   dont_translate = 1;
 484                   goto out;
 485                 }
 486               b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 487               next = NAT_NEXT_DROP;
 488               goto out;
 489             }
 490           else
 491             {
 492               dont_translate = 1;
 493               if (next_src_nat (sm, ip, key.proto, key.l_port, key.r_port,
 494                                 thread_index, rx_fib_index))
 495                 {
 496                   next = NAT_NEXT_IN2OUT_ED_FAST_PATH;
 497                   goto out;
 498                 }
 499               if (sm->num_workers > 1)
 500                 create_bypass_for_fwd_worker (sm, b, ip, rx_fib_index);
 501               else
 502                 create_bypass_for_fwd (sm, b, ip, rx_fib_index, thread_index);
 503               goto out;
 504             }
 505         }
 506
 507       if (PREDICT_FALSE
 508           (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 509            ICMP4_echo_reply
 510            && (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 511                ICMP4_echo_request || !is_addr_only)))
 512         {
 513           b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 514           next = NAT_NEXT_DROP;
 515           goto out;
 516         }
 517
 518       if (PREDICT_FALSE (identity_nat))
 519         {
 520           dont_translate = 1;
 521           goto out;
 522         }
 523
 524       /* Create session initiated by host from external network */
 525       s = create_session_for_static_mapping_ed (sm, b, l_key, e_key, node,
 526                                                 thread_index, 0, 0,
 527                                                 vlib_time_now
 528                                                 (sm->vlib_main));
 529
 530       if (!s)
 531         {
 532           next = NAT_NEXT_DROP;
 533           goto out;
 534         }
 535     }
 536   else
 537     {
 538       if (PREDICT_FALSE
 539           (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 540            ICMP4_echo_reply
 541            && vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 542            ICMP4_echo_request
 543            && !icmp_type_is_error_message (vnet_buffer (b)->ip.
 544                                            reass.icmp_type_or_tcp_flags)))
 545         {
 546           b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 547           next = NAT_NEXT_DROP;
 548           goto out;
 549         }
 550
 551       s = pool_elt_at_index (tsm->sessions, value.value);
 552     }
 553
 554   *p_proto = ip_proto_to_snat_proto (key.proto);
 555 out:
 556   if (s)
 557     *p_value = s->in2out;
 558   *p_dont_translate = dont_translate;
 559   if (d)
 560     *(snat_session_t **) d = s;
 561   return next;
 562 }
 563 #endif
 564
 565 static snat_session_t *
 566 nat44_ed_out2in_unknown_proto (snat_main_t * sm,
 567                                vlib_buffer_t * b,
 568                                ip4_header_t * ip,
 569                                u32 rx_fib_index,
 570                                u32 thread_index,
 571                                f64 now,
 572                                vlib_main_t * vm, vlib_node_runtime_t * node)
 573 {
 574   clib_bihash_kv_8_8_t kv, value;
 575   clib_bihash_kv_16_8_t s_kv, s_value;
 576   snat_static_mapping_t *m;
 577   u32 old_addr, new_addr;
 578   ip_csum_t sum;
 579   snat_session_t *s;
 580   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 581   snat_user_t *u;
 582
 583   old_addr = ip->dst_address.as_u32;
 584
 585   make_ed_kv (&s_kv, &ip->dst_address, &ip->src_address, ip->protocol,
 586               rx_fib_index, 0, 0);
 587
 588   if (!clib_bihash_search_16_8 (&tsm->out2in_ed, &s_kv, &s_value))
 589     {
 590       s = pool_elt_at_index (tsm->sessions, s_value.value);
 591       new_addr = ip->dst_address.as_u32 = s->in2out.addr.as_u32;
 592     }
 593   else
 594     {
 595       if (PREDICT_FALSE (maximum_sessions_exceeded (sm, thread_index)))
 596         {
 597           b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 598           nat_elog_notice ("maximum sessions exceeded");
 599           return 0;
 600         }
 601
 602       make_sm_kv (&kv, &ip->dst_address, 0, 0, 0);
 603       if (clib_bihash_search_8_8
 604           (&sm->static_mapping_by_external, &kv, &value))
 605         {
 606           b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 607           return 0;
 608         }
 609
 610       m = pool_elt_at_index (sm->static_mappings, value.value);
 611
 612       new_addr = ip->dst_address.as_u32 = m->local_addr.as_u32;
 613
 614       u = nat_user_get_or_create (sm, &m->local_addr, m->fib_index,
 615                                   thread_index);
 616       if (!u)
 617         {
 618           nat_elog_warn ("create NAT user failed");
 619           return 0;
 620         }
 621
 622       /* Create a new session */
 623       s = nat_ed_session_alloc (sm, u, thread_index, now);
 624       if (!s)
 625         {
 626           nat44_delete_user_with_no_session (sm, u, thread_index);
 627           nat_elog_warn ("create NAT session failed");
 628           return 0;
 629         }
 630
 631       s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 632       s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 633       s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 634       s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 635       s->out2in.addr.as_u32 = old_addr;
 636       s->out2in.fib_index = rx_fib_index;
 637       s->in2out.addr.as_u32 = new_addr;
 638       s->in2out.fib_index = m->fib_index;
 639       s->in2out.port = s->out2in.port = ip->protocol;
 640       user_session_increment (sm, u, 1);
 641
 642       /* Add to lookup tables */
 643       s_kv.value = s - tsm->sessions;
 644       if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &s_kv, 1))
 645         nat_elog_notice ("out2in key add failed");
 646
 647       make_ed_kv (&s_kv, &ip->dst_address, &ip->src_address, ip->protocol,
 648                   m->fib_index, 0, 0);
 649       s_kv.value = s - tsm->sessions;
 650       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &s_kv, 1))
 651         nat_elog_notice ("in2out key add failed");
 652     }
 653
 654   /* Update IP checksum */
 655   sum = ip->checksum;
 656   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
 657   ip->checksum = ip_csum_fold (sum);
 658
 659   vnet_buffer (b)->sw_if_index[VLIB_TX] = s->in2out.fib_index;
 660
 661   /* Accounting */
 662   nat44_session_update_counters (s, now, vlib_buffer_length_in_chain (vm, b),
 663                                  thread_index);
 664   /* Per-user LRU list maintenance */
 665   nat44_session_update_lru (sm, s, thread_index);
 666
 667   return s;
 668 }
 669
 670 static inline uword
 671 nat44_ed_out2in_node_fn_inline (vlib_main_t * vm,
 672                                 vlib_node_runtime_t * node,
 673                                 vlib_frame_t * frame, int is_slow_path)
 674 {
 675   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
 676   nat_next_t next_index;
 677   snat_main_t *sm = &snat_main;
 678   f64 now = vlib_time_now (vm);
 679   u32 thread_index = vm->thread_index;
 680   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 681   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 682     0, fragments = 0;
 683
 684   stats_node_index = is_slow_path ? sm->ed_out2in_slowpath_node_index :
 685     sm->ed_out2in_node_index;
 686
 687   from = vlib_frame_vector_args (frame);
 688   n_left_from = frame->n_vectors;
 689   next_index = node->cached_next_index;
 690
 691   while (n_left_from > 0)
 692     {
 693       u32 n_left_to_next;
 694
 695       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 696
 697       while (n_left_from >= 4 && n_left_to_next >= 2)
 698         {
 699           u32 bi0, bi1;
 700           vlib_buffer_t *b0, *b1;
 701           u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
 702             new_addr0;
 703           u32 next1, sw_if_index1, rx_fib_index1, proto1, old_addr1,
 704             new_addr1;
 705           u16 old_port0, new_port0, old_port1, new_port1;
 706           ip4_header_t *ip0, *ip1;
 707           udp_header_t *udp0, *udp1;
 708           tcp_header_t *tcp0, *tcp1;
 709           icmp46_header_t *icmp0, *icmp1;
 710           snat_session_t *s0 = 0, *s1 = 0;
 711           clib_bihash_kv_16_8_t kv0, value0, kv1, value1;
 712           ip_csum_t sum0, sum1;
 713           snat_session_key_t e_key0, l_key0, e_key1, l_key1;
 714           lb_nat_type_t lb_nat0, lb_nat1;
 715           twice_nat_type_t twice_nat0, twice_nat1;
 716           u8 identity_nat0, identity_nat1;
 717
 718           /* Prefetch next iteration. */
 719           {
 720             vlib_buffer_t *p2, *p3;
 721
 722             p2 = vlib_get_buffer (vm, from[2]);
 723             p3 = vlib_get_buffer (vm, from[3]);
 724
 725             vlib_prefetch_buffer_header (p2, LOAD);
 726             vlib_prefetch_buffer_header (p3, LOAD);
 727
 728             CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE);
 729             CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE);
 730           }
 731
 732           /* speculatively enqueue b0 and b1 to the current next frame */
 733           to_next[0] = bi0 = from[0];
 734           to_next[1] = bi1 = from[1];
 735           from += 2;
 736           to_next += 2;
 737           n_left_from -= 2;
 738           n_left_to_next -= 2;
 739
 740           b0 = vlib_get_buffer (vm, bi0);
 741           b1 = vlib_get_buffer (vm, bi1);
 742
 743           next0 = nat_buffer_opaque (b0)->arc_next;
 744           next1 = nat_buffer_opaque (b1)->arc_next;
 745
 746           vnet_buffer (b0)->snat.flags = 0;
 747           ip0 = vlib_buffer_get_current (b0);
 748
 749           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 750           rx_fib_index0 =
 751             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 752                                                  sw_if_index0);
 753
 754           if (PREDICT_FALSE (ip0->ttl == 1))
 755             {
 756               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 757               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 758                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 759                                            0);
 760               next0 = NAT_NEXT_ICMP_ERROR;
 761               goto trace00;
 762             }
 763
 764           udp0 = ip4_next_header (ip0);
 765           tcp0 = (tcp_header_t *) udp0;
 766           icmp0 = (icmp46_header_t *) udp0;
 767           proto0 = ip_proto_to_snat_proto (ip0->protocol);
 768
 769           if (is_slow_path)
 770             {
 771               if (PREDICT_FALSE (proto0 == ~0))
 772                 {
 773                   s0 =
 774                     nat44_ed_out2in_unknown_proto (sm, b0, ip0, rx_fib_index0,
 775                                                    thread_index, now, vm,
 776                                                    node);
 777                   other_packets++;
 778                   if (!sm->forwarding_enabled)
 779                     {
 780                       if (!s0)
 781                         next0 = NAT_NEXT_DROP;
 782                       goto trace00;
 783                     }
 784                 }
 785
 786               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
 787                 {
 788                   next0 = icmp_out2in_ed_slow_path
 789                     (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
 790                      next0, now, thread_index, &s0);
 791                   icmp_packets++;
 792                   goto trace00;
 793                 }
 794             }
 795           else
 796             {
 797               if (PREDICT_FALSE (proto0 == ~0))
 798                 {
 799                   next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 800                   goto trace00;
 801                 }
 802
 803               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
 804                 {
 805                   next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 806                   goto trace00;
 807                 }
 808             }
 809
 810           make_ed_kv (&kv0, &ip0->dst_address, &ip0->src_address,
 811                       ip0->protocol, rx_fib_index0,
 812                       vnet_buffer (b0)->ip.reass.l4_dst_port,
 813                       vnet_buffer (b0)->ip.reass.l4_src_port);
 814
 815           if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv0, &value0))
 816             {
 817               if (is_slow_path)
 818                 {
 819                   /* Try to match static mapping by external address and port,
 820                      destination address and port in packet */
 821                   e_key0.addr = ip0->dst_address;
 822                   e_key0.port = vnet_buffer (b0)->ip.reass.l4_dst_port;
 823                   e_key0.protocol = proto0;
 824                   e_key0.fib_index = rx_fib_index0;
 825                   if (snat_static_mapping_match (sm, e_key0, &l_key0, 1, 0,
 826                                                  &twice_nat0, &lb_nat0,
 827                                                  &ip0->src_address,
 828                                                  &identity_nat0))
 829                     {
 830                       /*
 831                        * Send DHCP packets to the ipv4 stack, or we won't
 832                        * be able to use dhcp client on the outside interface
 833                        */
 834                       if (PREDICT_FALSE
 835                           (proto0 == SNAT_PROTOCOL_UDP
 836                            && (vnet_buffer (b0)->ip.reass.l4_dst_port ==
 837                                clib_host_to_net_u16
 838                                (UDP_DST_PORT_dhcp_to_client))))
 839                         {
 840                           goto trace00;
 841                         }
 842
 843                       if (!sm->forwarding_enabled)
 844                         {
 845                           b0->error =
 846                             node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 847                           next0 = NAT_NEXT_DROP;
 848                         }
 849                       else
 850                         {
 851                           if (next_src_nat
 852                               (sm, ip0, ip0->protocol,
 853                                vnet_buffer (b0)->ip.reass.l4_src_port,
 854                                vnet_buffer (b0)->ip.reass.l4_dst_port,
 855                                thread_index, rx_fib_index0))
 856                             {
 857                               next0 = NAT_NEXT_IN2OUT_ED_FAST_PATH;
 858                               goto trace00;
 859                             }
 860                           if (sm->num_workers > 1)
 861                             create_bypass_for_fwd_worker (sm, b0, ip0,
 862                                                           rx_fib_index0);
 863                           else
 864                             create_bypass_for_fwd (sm, b0, ip0, rx_fib_index0,
 865                                                    thread_index);
 866                         }
 867                       goto trace00;
 868                     }
 869
 870                   if (PREDICT_FALSE (identity_nat0))
 871                     goto trace00;
 872
 873                   if ((proto0 == SNAT_PROTOCOL_TCP)
 874                       && !tcp_flags_is_init (vnet_buffer (b0)->ip.
 875                                              reass.icmp_type_or_tcp_flags))
 876                     {
 877                       b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
 878                       next0 = NAT_NEXT_DROP;
 879                       goto trace00;
 880                     }
 881
 882                   /* Create session initiated by host from external network */
 883                   s0 = create_session_for_static_mapping_ed (sm, b0, l_key0,
 884                                                              e_key0, node,
 885                                                              thread_index,
 886                                                              twice_nat0,
 887                                                              lb_nat0, now);
 888
 889                   if (!s0)
 890                     {
 891                       next0 = NAT_NEXT_DROP;
 892                       goto trace00;
 893                     }
 894                 }
 895               else
 896                 {
 897                   next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 898                   goto trace00;
 899                 }
 900             }
 901           else
 902             {
 903               s0 = pool_elt_at_index (tsm->sessions, value0.value);
 904             }
 905
 906           old_addr0 = ip0->dst_address.as_u32;
 907           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
 908           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
 909
 910           sum0 = ip0->checksum;
 911           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 912                                  dst_address);
 913           if (PREDICT_FALSE (is_twice_nat_session (s0)))
 914             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 915                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
 916                                    src_address);
 917           ip0->checksum = ip_csum_fold (sum0);
 918
 919           old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
 920
 921           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
 922             {
 923               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 924                 {
 925                   new_port0 = udp0->dst_port = s0->in2out.port;
 926                   sum0 = tcp0->checksum;
 927                   sum0 =
 928                     ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 929                                     dst_address);
 930                   sum0 =
 931                     ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 932                                     length);
 933                   if (is_twice_nat_session (s0))
 934                     {
 935                       sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 936                                              s0->ext_host_nat_addr.as_u32,
 937                                              ip4_header_t, dst_address);
 938                       sum0 =
 939                         ip_csum_update (sum0,
 940                                         vnet_buffer (b0)->ip.
 941                                         reass.l4_src_port,
 942                                         s0->ext_host_nat_port, ip4_header_t,
 943                                         length);
 944                       tcp0->src_port = s0->ext_host_nat_port;
 945                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 946                     }
 947                   tcp0->checksum = ip_csum_fold (sum0);
 948                 }
 949               tcp_packets++;
 950               if (nat44_set_tcp_session_state_o2i
 951                   (sm, s0, vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags,
 952                    vnet_buffer (b0)->ip.reass.tcp_ack_number,
 953                    vnet_buffer (b0)->ip.reass.tcp_seq_number, thread_index))
 954                 goto trace00;
 955             }
 956           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
 957                    && udp0->checksum)
 958             {
 959               new_port0 = udp0->dst_port = s0->in2out.port;
 960               sum0 = udp0->checksum;
 961               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 962                                      dst_address);
 963               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 964                                      length);
 965               if (PREDICT_FALSE (is_twice_nat_session (s0)))
 966                 {
 967                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 968                                          s0->ext_host_nat_addr.as_u32,
 969                                          ip4_header_t, dst_address);
 970                   sum0 =
 971                     ip_csum_update (sum0,
 972                                     vnet_buffer (b0)->ip.reass.l4_src_port,
 973                                     s0->ext_host_nat_port, ip4_header_t,
 974                                     length);
 975                   udp0->src_port = s0->ext_host_nat_port;
 976                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 977                 }
 978               udp0->checksum = ip_csum_fold (sum0);
 979               udp_packets++;
 980             }
 981           else
 982             {
 983               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 984                 {
 985                   new_port0 = udp0->dst_port = s0->in2out.port;
 986                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
 987                     {
 988                       udp0->dst_port = s0->in2out.port;
 989                       if (is_twice_nat_session (s0))
 990                         {
 991                           udp0->src_port = s0->ext_host_nat_port;
 992                           ip0->src_address.as_u32 =
 993                             s0->ext_host_nat_addr.as_u32;
 994                         }
 995                       udp0->checksum = 0;
 996                     }
 997                 }
 998               udp_packets++;
 999             }
1000
1001           /* Accounting */
1002           nat44_session_update_counters (s0, now,
1003                                          vlib_buffer_length_in_chain (vm, b0),
1004                                          thread_index);
1005           /* Per-user LRU list maintenance */
1006           nat44_session_update_lru (sm, s0, thread_index);
1007
1008         trace00:
1009           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1010                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1011             {
1012               nat44_ed_out2in_trace_t *t =
1013                 vlib_add_trace (vm, node, b0, sizeof (*t));
1014               t->is_slow_path = is_slow_path;
1015               t->sw_if_index = sw_if_index0;
1016               t->next_index = next0;
1017               t->session_index = ~0;
1018               if (s0)
1019                 t->session_index = s0 - tsm->sessions;
1020             }
1021
1022           pkts_processed += next0 == nat_buffer_opaque (b0)->arc_next;
1023
1024           vnet_buffer (b1)->snat.flags = 0;
1025           ip1 = vlib_buffer_get_current (b1);
1026
1027           sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];
1028           rx_fib_index1 =
1029             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
1030                                                  sw_if_index1);
1031
1032           if (PREDICT_FALSE (ip1->ttl == 1))
1033             {
1034               vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1035               icmp4_error_set_vnet_buffer (b1, ICMP4_time_exceeded,
1036                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1037                                            0);
1038               next1 = NAT_NEXT_ICMP_ERROR;
1039               goto trace01;
1040             }
1041
1042           udp1 = ip4_next_header (ip1);
1043           tcp1 = (tcp_header_t *) udp1;
1044           icmp1 = (icmp46_header_t *) udp1;
1045           proto1 = ip_proto_to_snat_proto (ip1->protocol);
1046
1047           if (is_slow_path)
1048             {
1049               if (PREDICT_FALSE (proto1 == ~0))
1050                 {
1051                   s1 =
1052                     nat44_ed_out2in_unknown_proto (sm, b1, ip1, rx_fib_index1,
1053                                                    thread_index, now, vm,
1054                                                    node);
1055                   other_packets++;
1056                   if (!sm->forwarding_enabled)
1057                     {
1058                       if (!s1)
1059                         next1 = NAT_NEXT_DROP;
1060                       goto trace01;
1061                     }
1062                 }
1063
1064               if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP))
1065                 {
1066                   next1 = icmp_out2in_ed_slow_path
1067                     (sm, b1, ip1, icmp1, sw_if_index1, rx_fib_index1, node,
1068                      next1, now, thread_index, &s1);
1069                   icmp_packets++;
1070                   goto trace01;
1071                 }
1072             }
1073           else
1074             {
1075               if (PREDICT_FALSE (proto1 == ~0))
1076                 {
1077                   next1 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
1078                   goto trace01;
1079                 }
1080
1081               if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP))
1082                 {
1083                   next1 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
1084                   goto trace01;
1085                 }
1086             }
1087
1088           make_ed_kv (&kv1, &ip1->dst_address, &ip1->src_address,
1089                       ip1->protocol, rx_fib_index1,
1090                       vnet_buffer (b1)->ip.reass.l4_dst_port,
1091                       vnet_buffer (b1)->ip.reass.l4_src_port);
1092
1093           if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv1, &value1))
1094             {
1095               if (is_slow_path)
1096                 {
1097                   /* Try to match static mapping by external address and port,
1098                      destination address and port in packet */
1099                   e_key1.addr = ip1->dst_address;
1100                   e_key1.port = vnet_buffer (b1)->ip.reass.l4_dst_port;
1101                   e_key1.protocol = proto1;
1102                   e_key1.fib_index = rx_fib_index1;
1103                   if (snat_static_mapping_match (sm, e_key1, &l_key1, 1, 0,
1104                                                  &twice_nat1, &lb_nat1,
1105                                                  &ip1->src_address,
1106                                                  &identity_nat1))
1107                     {
1108                       /*
1109                        * Send DHCP packets to the ipv4 stack, or we won't
1110                        * be able to use dhcp client on the outside interface
1111                        */
1112                       if (PREDICT_FALSE
1113                           (proto1 == SNAT_PROTOCOL_UDP
1114                            && (vnet_buffer (b1)->ip.reass.l4_dst_port ==
1115                                clib_host_to_net_u16
1116                                (UDP_DST_PORT_dhcp_to_client))))
1117                         {
1118                           goto trace01;
1119                         }
1120
1121                       if (!sm->forwarding_enabled)
1122                         {
1123                           b1->error =
1124                             node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
1125                           next1 = NAT_NEXT_DROP;
1126                         }
1127                       else
1128                         {
1129                           if (next_src_nat
1130                               (sm, ip1, ip1->protocol,
1131                                vnet_buffer (b1)->ip.reass.l4_src_port,
1132                                vnet_buffer (b1)->ip.reass.l4_dst_port,
1133                                thread_index, rx_fib_index1))
1134                             {
1135                               next1 = NAT_NEXT_IN2OUT_ED_FAST_PATH;
1136                               goto trace01;
1137                             }
1138                           if (sm->num_workers > 1)
1139                             create_bypass_for_fwd_worker (sm, b1, ip1,
1140                                                           rx_fib_index1);
1141                           else
1142                             create_bypass_for_fwd (sm, b1, ip1, rx_fib_index1,
1143                                                    thread_index);
1144                         }
1145                       goto trace01;
1146                     }
1147
1148                   if (PREDICT_FALSE (identity_nat1))
1149                     goto trace01;
1150
1151                   if ((proto1 == SNAT_PROTOCOL_TCP)
1152                       && !tcp_flags_is_init (vnet_buffer (b1)->ip.
1153                                              reass.icmp_type_or_tcp_flags))
1154                     {
1155                       b1->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
1156                       next1 = NAT_NEXT_DROP;
1157                       goto trace01;
1158                     }
1159
1160                   /* Create session initiated by host from external network */
1161                   s1 = create_session_for_static_mapping_ed (sm, b1, l_key1,
1162                                                              e_key1, node,
1163                                                              thread_index,
1164                                                              twice_nat1,
1165                                                              lb_nat1, now);
1166
1167                   if (!s1)
1168                     {
1169                       next1 = NAT_NEXT_DROP;
1170                       goto trace01;
1171                     }
1172                 }
1173               else
1174                 {
1175                   next1 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
1176                   goto trace01;
1177                 }
1178             }
1179           else
1180             {
1181               s1 = pool_elt_at_index (tsm->sessions, value1.value);
1182             }
1183
1184           old_addr1 = ip1->dst_address.as_u32;
1185           new_addr1 = ip1->dst_address.as_u32 = s1->in2out.addr.as_u32;
1186           vnet_buffer (b1)->sw_if_index[VLIB_TX] = s1->in2out.fib_index;
1187
1188           sum1 = ip1->checksum;
1189           sum1 = ip_csum_update (sum1, old_addr1, new_addr1, ip4_header_t,
1190                                  dst_address);
1191           if (PREDICT_FALSE (is_twice_nat_session (s1)))
1192             sum1 = ip_csum_update (sum1, ip1->src_address.as_u32,
1193                                    s1->ext_host_nat_addr.as_u32, ip4_header_t,
1194                                    src_address);
1195           ip1->checksum = ip_csum_fold (sum1);
1196
1197           old_port1 = vnet_buffer (b1)->ip.reass.l4_dst_port;
1198
1199           if (PREDICT_TRUE (proto1 == SNAT_PROTOCOL_TCP))
1200             {
1201               if (!vnet_buffer (b1)->ip.reass.is_non_first_fragment)
1202                 {
1203                   new_port1 = udp1->dst_port = s1->in2out.port;
1204
1205                   sum1 = tcp1->checksum;
1206                   sum1 =
1207                     ip_csum_update (sum1, old_addr1, new_addr1, ip4_header_t,
1208                                     dst_address);
1209                   sum1 =
1210                     ip_csum_update (sum1, old_port1, new_port1, ip4_header_t,
1211                                     length);
1212                   if (is_twice_nat_session (s1))
1213                     {
1214                       sum1 = ip_csum_update (sum1, ip1->src_address.as_u32,
1215                                              s1->ext_host_nat_addr.as_u32,
1216                                              ip4_header_t, dst_address);
1217                       sum1 =
1218                         ip_csum_update (sum1,
1219                                         vnet_buffer (b1)->ip.
1220                                         reass.l4_src_port,
1221                                         s1->ext_host_nat_port, ip4_header_t,
1222                                         length);
1223                       tcp1->src_port = s1->ext_host_nat_port;
1224                       ip1->src_address.as_u32 = s1->ext_host_nat_addr.as_u32;
1225                     }
1226                   tcp1->checksum = ip_csum_fold (sum1);
1227                 }
1228               tcp_packets++;
1229               if (nat44_set_tcp_session_state_o2i
1230                   (sm, s1, vnet_buffer (b1)->ip.reass.icmp_type_or_tcp_flags,
1231                    vnet_buffer (b1)->ip.reass.tcp_ack_number,
1232                    vnet_buffer (b1)->ip.reass.tcp_seq_number, thread_index))
1233                 goto trace01;
1234             }
1235           else if (!vnet_buffer (b1)->ip.reass.is_non_first_fragment
1236                    && udp1->checksum)
1237             {
1238               new_port1 = udp1->dst_port = s1->in2out.port;
1239               sum1 = udp1->checksum;
1240               sum1 = ip_csum_update (sum1, old_addr1, new_addr1, ip4_header_t,
1241                                      dst_address);
1242               sum1 = ip_csum_update (sum1, old_port1, new_port1, ip4_header_t,
1243                                      length);
1244               if (PREDICT_FALSE (is_twice_nat_session (s1)))
1245                 {
1246                   sum1 = ip_csum_update (sum1, ip1->src_address.as_u32,
1247                                          s1->ext_host_nat_addr.as_u32,
1248                                          ip4_header_t, dst_address);
1249                   sum1 =
1250                     ip_csum_update (sum1,
1251                                     vnet_buffer (b1)->ip.reass.l4_src_port,
1252                                     s1->ext_host_nat_port, ip4_header_t,
1253                                     length);
1254                   udp1->src_port = s1->ext_host_nat_port;
1255                   ip1->src_address.as_u32 = s1->ext_host_nat_addr.as_u32;
1256                 }
1257               udp1->checksum = ip_csum_fold (sum1);
1258               udp_packets++;
1259             }
1260           else
1261             {
1262               if (!vnet_buffer (b1)->ip.reass.is_non_first_fragment)
1263                 {
1264                   if (PREDICT_FALSE (is_twice_nat_session (s1)))
1265                     {
1266                       udp1->dst_port = s1->in2out.port;
1267                       if (is_twice_nat_session (s1))
1268                         {
1269                           udp1->src_port = s1->ext_host_nat_port;
1270                           ip1->src_address.as_u32 =
1271                             s1->ext_host_nat_addr.as_u32;
1272                         }
1273                       udp1->checksum = 0;
1274                     }
1275                 }
1276               udp_packets++;
1277             }
1278
1279           /* Accounting */
1280           nat44_session_update_counters (s1, now,
1281                                          vlib_buffer_length_in_chain (vm, b1),
1282                                          thread_index);
1283           /* Per-user LRU list maintenance */
1284           nat44_session_update_lru (sm, s1, thread_index);
1285
1286         trace01:
1287           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1288                              && (b1->flags & VLIB_BUFFER_IS_TRACED)))
1289             {
1290               nat44_ed_out2in_trace_t *t =
1291                 vlib_add_trace (vm, node, b1, sizeof (*t));
1292               t->is_slow_path = is_slow_path;
1293               t->sw_if_index = sw_if_index1;
1294               t->next_index = next1;
1295               t->session_index = ~0;
1296               if (s1)
1297                 t->session_index = s1 - tsm->sessions;
1298             }
1299
1300           pkts_processed += next1 == nat_buffer_opaque (b1)->arc_next;
1301
1302           /* verify speculative enqueues, maybe switch current next frame */
1303           vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
1304                                            to_next, n_left_to_next,
1305                                            bi0, bi1, next0, next1);
1306         }
1307
1308       while (n_left_from > 0 && n_left_to_next > 0)
1309         {
1310           u32 bi0;
1311           vlib_buffer_t *b0;
1312           u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
1313             new_addr0;
1314           u16 old_port0, new_port0;
1315           ip4_header_t *ip0;
1316           udp_header_t *udp0;
1317           tcp_header_t *tcp0;
1318           icmp46_header_t *icmp0;
1319           snat_session_t *s0 = 0;
1320           clib_bihash_kv_16_8_t kv0, value0;
1321           ip_csum_t sum0;
1322           snat_session_key_t e_key0, l_key0;
1323           lb_nat_type_t lb_nat0;
1324           twice_nat_type_t twice_nat0;
1325           u8 identity_nat0;
1326
1327           /* speculatively enqueue b0 to the current next frame */
1328           bi0 = from[0];
1329           to_next[0] = bi0;
1330           from += 1;
1331           to_next += 1;
1332           n_left_from -= 1;
1333           n_left_to_next -= 1;
1334
1335           b0 = vlib_get_buffer (vm, bi0);
1336           next0 = nat_buffer_opaque (b0)->arc_next;
1337
1338           vnet_buffer (b0)->snat.flags = 0;
1339           ip0 = vlib_buffer_get_current (b0);
1340
1341           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1342           rx_fib_index0 =
1343             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
1344                                                  sw_if_index0);
1345
1346           if (PREDICT_FALSE (ip0->ttl == 1))
1347             {
1348               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1349               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1350                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1351                                            0);
1352               next0 = NAT_NEXT_ICMP_ERROR;
1353               goto trace0;
1354             }
1355
1356           udp0 = ip4_next_header (ip0);
1357           tcp0 = (tcp_header_t *) udp0;
1358           icmp0 = (icmp46_header_t *) udp0;
1359           proto0 = ip_proto_to_snat_proto (ip0->protocol);
1360
1361           if (is_slow_path)
1362             {
1363               if (PREDICT_FALSE (proto0 == ~0))
1364                 {
1365                   s0 =
1366                     nat44_ed_out2in_unknown_proto (sm, b0, ip0, rx_fib_index0,
1367                                                    thread_index, now, vm,
1368                                                    node);
1369                   other_packets++;
1370                   if (!sm->forwarding_enabled)
1371                     {
1372                       if (!s0)
1373                         next0 = NAT_NEXT_DROP;
1374                       goto trace0;
1375                     }
1376                 }
1377
1378               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1379                 {
1380                   next0 = icmp_out2in_ed_slow_path
1381                     (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1382                      next0, now, thread_index, &s0);
1383                   icmp_packets++;
1384                   goto trace0;
1385                 }
1386             }
1387           else
1388             {
1389               if (PREDICT_FALSE (proto0 == ~0))
1390                 {
1391                   next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
1392                   goto trace0;
1393                 }
1394
1395               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1396                 {
1397                   next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
1398                   goto trace0;
1399                 }
1400             }
1401
1402           make_ed_kv (&kv0, &ip0->dst_address, &ip0->src_address,
1403                       ip0->protocol, rx_fib_index0,
1404                       vnet_buffer (b0)->ip.reass.l4_dst_port,
1405                       vnet_buffer (b0)->ip.reass.l4_src_port);
1406
1407           if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv0, &value0))
1408             {
1409               if (is_slow_path)
1410                 {
1411                   /* Try to match static mapping by external address and port,
1412                      destination address and port in packet */
1413                   e_key0.addr = ip0->dst_address;
1414                   e_key0.port = vnet_buffer (b0)->ip.reass.l4_dst_port;
1415                   e_key0.protocol = proto0;
1416                   e_key0.fib_index = rx_fib_index0;
1417                   if (snat_static_mapping_match (sm, e_key0, &l_key0, 1, 0,
1418                                                  &twice_nat0, &lb_nat0,
1419                                                  &ip0->src_address,
1420                                                  &identity_nat0))
1421                     {
1422                       /*
1423                        * Send DHCP packets to the ipv4 stack, or we won't
1424                        * be able to use dhcp client on the outside interface
1425                        */
1426                       if (PREDICT_FALSE
1427                           (proto0 == SNAT_PROTOCOL_UDP
1428                            && (vnet_buffer (b0)->ip.reass.l4_dst_port ==
1429                                clib_host_to_net_u16
1430                                (UDP_DST_PORT_dhcp_to_client))))
1431                         {
1432                           goto trace0;
1433                         }
1434
1435                       if (!sm->forwarding_enabled)
1436                         {
1437                           b0->error =
1438                             node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
1439                           next0 = NAT_NEXT_DROP;
1440                         }
1441                       else
1442                         {
1443                           if (next_src_nat
1444                               (sm, ip0, ip0->protocol,
1445                                vnet_buffer (b0)->ip.reass.l4_src_port,
1446                                vnet_buffer (b0)->ip.reass.l4_dst_port,
1447                                thread_index, rx_fib_index0))
1448                             {
1449                               next0 = NAT_NEXT_IN2OUT_ED_FAST_PATH;
1450                               goto trace0;
1451                             }
1452                           if (sm->num_workers > 1)
1453                             create_bypass_for_fwd_worker (sm, b0, ip0,
1454                                                           rx_fib_index0);
1455                           else
1456                             create_bypass_for_fwd (sm, b0, ip0, rx_fib_index0,
1457                                                    thread_index);
1458                         }
1459                       goto trace0;
1460                     }
1461
1462                   if (PREDICT_FALSE (identity_nat0))
1463                     goto trace0;
1464
1465                   if ((proto0 == SNAT_PROTOCOL_TCP)
1466                       && !tcp_flags_is_init (vnet_buffer (b0)->ip.
1467                                              reass.icmp_type_or_tcp_flags))
1468                     {
1469                       b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
1470                       next0 = NAT_NEXT_DROP;
1471                       goto trace0;
1472                     }
1473
1474                   /* Create session initiated by host from external network */
1475                   s0 = create_session_for_static_mapping_ed (sm, b0, l_key0,
1476                                                              e_key0, node,
1477                                                              thread_index,
1478                                                              twice_nat0,
1479                                                              lb_nat0, now);
1480
1481                   if (!s0)
1482                     {
1483                       next0 = NAT_NEXT_DROP;
1484                       goto trace0;
1485                     }
1486                 }
1487               else
1488                 {
1489                   next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
1490                   goto trace0;
1491                 }
1492             }
1493           else
1494             {
1495               s0 = pool_elt_at_index (tsm->sessions, value0.value);
1496             }
1497
1498           old_addr0 = ip0->dst_address.as_u32;
1499           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
1500           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
1501
1502           sum0 = ip0->checksum;
1503           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1504                                  dst_address);
1505           if (PREDICT_FALSE (is_twice_nat_session (s0)))
1506             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1507                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
1508                                    src_address);
1509           ip0->checksum = ip_csum_fold (sum0);
1510
1511           old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
1512
1513           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
1514             {
1515               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1516                 {
1517                   new_port0 = udp0->dst_port = s0->in2out.port;
1518                   sum0 = tcp0->checksum;
1519                   sum0 =
1520                     ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1521                                     dst_address);
1522                   sum0 =
1523                     ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1524                                     length);
1525                   if (is_twice_nat_session (s0))
1526                     {
1527                       sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1528                                              s0->ext_host_nat_addr.as_u32,
1529                                              ip4_header_t, dst_address);
1530                       sum0 =
1531                         ip_csum_update (sum0,
1532                                         vnet_buffer (b0)->ip.
1533                                         reass.l4_src_port,
1534                                         s0->ext_host_nat_port, ip4_header_t,
1535                                         length);
1536                       tcp0->src_port = s0->ext_host_nat_port;
1537                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1538                     }
1539                   tcp0->checksum = ip_csum_fold (sum0);
1540                 }
1541               tcp_packets++;
1542               if (nat44_set_tcp_session_state_o2i
1543                   (sm, s0, vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags,
1544                    vnet_buffer (b0)->ip.reass.tcp_ack_number,
1545                    vnet_buffer (b0)->ip.reass.tcp_seq_number, thread_index))
1546                 goto trace0;
1547             }
1548           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
1549                    && udp0->checksum)
1550             {
1551               new_port0 = udp0->dst_port = s0->in2out.port;
1552               sum0 = udp0->checksum;
1553               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1554                                      dst_address);
1555               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1556                                      length);
1557               if (PREDICT_FALSE (is_twice_nat_session (s0)))
1558                 {
1559                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1560                                          s0->ext_host_nat_addr.as_u32,
1561                                          ip4_header_t, dst_address);
1562                   sum0 =
1563                     ip_csum_update (sum0,
1564                                     vnet_buffer (b0)->ip.reass.l4_src_port,
1565                                     s0->ext_host_nat_port, ip4_header_t,
1566                                     length);
1567                   udp0->src_port = s0->ext_host_nat_port;
1568                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1569                 }
1570               udp0->checksum = ip_csum_fold (sum0);
1571               udp_packets++;
1572             }
1573           else
1574             {
1575               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1576                 {
1577                   new_port0 = udp0->dst_port = s0->in2out.port;
1578                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
1579                     {
1580                       udp0->src_port = s0->ext_host_nat_port;
1581                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1582                     }
1583                 }
1584               udp_packets++;
1585             }
1586
1587           /* Accounting */
1588           nat44_session_update_counters (s0, now,
1589                                          vlib_buffer_length_in_chain (vm, b0),
1590                                          thread_index);
1591           /* Per-user LRU list maintenance */
1592           nat44_session_update_lru (sm, s0, thread_index);
1593
1594         trace0:
1595           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1596                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1597             {
1598               nat44_ed_out2in_trace_t *t =
1599                 vlib_add_trace (vm, node, b0, sizeof (*t));
1600               t->is_slow_path = is_slow_path;
1601               t->sw_if_index = sw_if_index0;
1602               t->next_index = next0;
1603               t->session_index = ~0;
1604               if (s0)
1605                 t->session_index = s0 - tsm->sessions;
1606             }
1607
1608           pkts_processed += next0 == nat_buffer_opaque (b0)->arc_next;
1609           /* verify speculative enqueue, maybe switch current next frame */
1610           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1611                                            to_next, n_left_to_next,
1612                                            bi0, next0);
1613         }
1614
1615       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1616     }
1617
1618   vlib_node_increment_counter (vm, stats_node_index,
1619                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
1620                                pkts_processed);
1621   vlib_node_increment_counter (vm, stats_node_index,
1622                                NAT_OUT2IN_ED_ERROR_TCP_PACKETS, tcp_packets);
1623   vlib_node_increment_counter (vm, stats_node_index,
1624                                NAT_OUT2IN_ED_ERROR_UDP_PACKETS, udp_packets);
1625   vlib_node_increment_counter (vm, stats_node_index,
1626                                NAT_OUT2IN_ED_ERROR_ICMP_PACKETS,
1627                                icmp_packets);
1628   vlib_node_increment_counter (vm, stats_node_index,
1629                                NAT_OUT2IN_ED_ERROR_OTHER_PACKETS,
1630                                other_packets);
1631   vlib_node_increment_counter (vm, stats_node_index,
1632                                NAT_OUT2IN_ED_ERROR_FRAGMENTS, fragments);
1633   return frame->n_vectors;
1634 }
1635
1636 VLIB_NODE_FN (nat44_ed_out2in_node) (vlib_main_t * vm,
1637                                      vlib_node_runtime_t * node,
1638                                      vlib_frame_t * frame)
1639 {
1640   return nat44_ed_out2in_node_fn_inline (vm, node, frame, 0);
1641 }
1642
1643 /* *INDENT-OFF* */
1644 VLIB_REGISTER_NODE (nat44_ed_out2in_node) = {
1645   .name = "nat44-ed-out2in",
1646   .vector_size = sizeof (u32),
1647   .sibling_of = "nat-default",
1648   .format_trace = format_nat44_ed_out2in_trace,
1649   .type = VLIB_NODE_TYPE_INTERNAL,
1650   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1651   .error_strings = nat_out2in_ed_error_strings,
1652   .runtime_data_bytes = sizeof (snat_runtime_t),
1653 };
1654 /* *INDENT-ON* */
1655
1656 VLIB_NODE_FN (nat44_ed_out2in_slowpath_node) (vlib_main_t * vm,
1657                                               vlib_node_runtime_t * node,
1658                                               vlib_frame_t * frame)
1659 {
1660   return nat44_ed_out2in_node_fn_inline (vm, node, frame, 1);
1661 }
1662
1663 /* *INDENT-OFF* */
1664 VLIB_REGISTER_NODE (nat44_ed_out2in_slowpath_node) = {
1665   .name = "nat44-ed-out2in-slowpath",
1666   .vector_size = sizeof (u32),
1667   .sibling_of = "nat-default",
1668   .format_trace = format_nat44_ed_out2in_trace,
1669   .type = VLIB_NODE_TYPE_INTERNAL,
1670   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1671   .error_strings = nat_out2in_ed_error_strings,
1672   .runtime_data_bytes = sizeof (snat_runtime_t),
1673 };
1674 /* *INDENT-ON* */
1675
1676 static u8 *
1677 format_nat_pre_trace (u8 * s, va_list * args)
1678 {
1679   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1680   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1681   nat_pre_trace_t *t = va_arg (*args, nat_pre_trace_t *);
1682   return format (s, "out2in next_index %d", t->next_index);
1683 }
1684
1685 VLIB_NODE_FN (nat_pre_out2in_node) (vlib_main_t * vm,
1686                                     vlib_node_runtime_t * node,
1687                                     vlib_frame_t * frame)
1688 {
1689   return nat_pre_node_fn_inline (vm, node, frame,
1690                                  NAT_NEXT_OUT2IN_ED_FAST_PATH);
1691 }
1692
1693 /* *INDENT-OFF* */
1694 VLIB_REGISTER_NODE (nat_pre_out2in_node) = {
1695   .name = "nat-pre-out2in",
1696   .vector_size = sizeof (u32),
1697   .sibling_of = "nat-default",
1698   .format_trace = format_nat_pre_trace,
1699   .type = VLIB_NODE_TYPE_INTERNAL,
1700   .n_errors = 0,
1701  };
1702 /* *INDENT-ON* */
1703
1704 /*
1705  * fd.io coding-style-patch-verification: ON
1706  *
1707  * Local Variables:
1708  * eval: (c-set-style "gnu")
1709  * End:
1710  */