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       ed_bihash_kv_t bihash_key;
 135       clib_memset (&bihash_key, 0, sizeof (bihash_key));
 136       bihash_key.k.dst_address = s->ext_host_addr.as_u32;
 137       bihash_key.k.dst_port = s->ext_host_port;
 138       bihash_key.k.src_address = s->out2in.addr.as_u32;
 139       bihash_key.k.src_port = s->out2in.port;
 140       bihash_key.k.protocol = s->out2in.protocol;
 141       clib_bihash_add_del_16_8 (&sm->ed_ext_ports, &bihash_key.kv,
 142                                 0 /* is_add */ );
 143
 144       if (snat_is_unk_proto_session (s))
 145         goto delete;
 146
 147       snat_ipfix_logging_nat44_ses_delete (ctx->thread_index,
 148                                            s->in2out.addr.as_u32,
 149                                            s->out2in.addr.as_u32,
 150                                            s->in2out.protocol,
 151                                            s->in2out.port,
 152                                            s->out2in.port,
 153                                            s->in2out.fib_index);
 154
 155       nat_syslog_nat44_sdel (s->user_index, s->in2out.fib_index,
 156                              &s->in2out.addr, s->in2out.port,
 157                              &s->ext_host_nat_addr, s->ext_host_nat_port,
 158                              &s->out2in.addr, s->out2in.port,
 159                              &s->ext_host_addr, s->ext_host_port,
 160                              s->in2out.protocol, is_twice_nat_session (s));
 161
 162       nat_ha_sdel (&s->out2in.addr, s->out2in.port, &s->ext_host_addr,
 163                    s->ext_host_port, s->out2in.protocol, s->out2in.fib_index,
 164                    ctx->thread_index);
 165
 166       if (is_twice_nat_session (s))
 167         {
 168           for (i = 0; i < vec_len (sm->twice_nat_addresses); i++)
 169             {
 170               key.protocol = s->in2out.protocol;
 171               key.port = s->ext_host_nat_port;
 172               a = sm->twice_nat_addresses + i;
 173               if (a->addr.as_u32 == s->ext_host_nat_addr.as_u32)
 174                 {
 175                   snat_free_outside_address_and_port (sm->twice_nat_addresses,
 176                                                       ctx->thread_index,
 177                                                       &key);
 178                   break;
 179                 }
 180             }
 181         }
 182
 183       if (snat_is_session_static (s))
 184         goto delete;
 185
 186       snat_free_outside_address_and_port (sm->addresses, ctx->thread_index,
 187                                           &s->out2in);
 188     delete:
 189       nat44_delete_session (sm, s, ctx->thread_index);
 190       return 1;
 191     }
 192
 193   return 0;
 194 }
 195 #endif
 196
 197 static snat_session_t *
 198 create_session_for_static_mapping_ed (snat_main_t * sm,
 199                                       vlib_buffer_t * b,
 200                                       snat_session_key_t l_key,
 201                                       snat_session_key_t e_key,
 202                                       vlib_node_runtime_t * node,
 203                                       u32 thread_index,
 204                                       twice_nat_type_t twice_nat,
 205                                       lb_nat_type_t lb_nat, f64 now)
 206 {
 207   snat_session_t *s;
 208   snat_user_t *u;
 209   ip4_header_t *ip;
 210   udp_header_t *udp;
 211   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 212   clib_bihash_kv_16_8_t kv;
 213   snat_session_key_t eh_key;
 214   nat44_is_idle_session_ctx_t ctx;
 215
 216   if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
 217     {
 218       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 219       nat_elog_notice ("maximum sessions exceeded");
 220       return 0;
 221     }
 222
 223   u = nat_user_get_or_create (sm, &l_key.addr, l_key.fib_index, thread_index);
 224   if (!u)
 225     {
 226       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 227       nat_elog_warn ("create NAT user failed");
 228       return 0;
 229     }
 230
 231   s = nat_ed_session_alloc (sm, u, thread_index, now);
 232   if (!s)
 233     {
 234       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_USER_SESS_EXCEEDED];
 235       nat44_delete_user_with_no_session (sm, u, thread_index);
 236       nat_elog_warn ("create NAT session failed");
 237       return 0;
 238     }
 239
 240   ip = vlib_buffer_get_current (b);
 241   udp = ip4_next_header (ip);
 242
 243   s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 244   s->ext_host_port = e_key.protocol == SNAT_PROTOCOL_ICMP ? 0 : udp->src_port;
 245   s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 246   if (lb_nat)
 247     s->flags |= SNAT_SESSION_FLAG_LOAD_BALANCING;
 248   if (lb_nat == AFFINITY_LB_NAT)
 249     s->flags |= SNAT_SESSION_FLAG_AFFINITY;
 250   s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 251   s->out2in = e_key;
 252   s->in2out = l_key;
 253   s->in2out.protocol = s->out2in.protocol;
 254   user_session_increment (sm, u, 1);
 255
 256   /* Add to lookup tables */
 257   make_ed_kv (&kv, &e_key.addr, &s->ext_host_addr, ip->protocol,
 258               e_key.fib_index, e_key.port, s->ext_host_port);
 259   kv.value = s - tsm->sessions;
 260   ctx.now = now;
 261   ctx.thread_index = thread_index;
 262   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->out2in_ed, &kv,
 263                                                nat44_o2i_ed_is_idle_session_cb,
 264                                                &ctx))
 265     nat_elog_notice ("out2in-ed key add failed");
 266
 267   if (twice_nat == TWICE_NAT || (twice_nat == TWICE_NAT_SELF &&
 268                                  ip->src_address.as_u32 == l_key.addr.as_u32))
 269     {
 270       eh_key.protocol = e_key.protocol;
 271       if (snat_alloc_outside_address_and_port (sm->twice_nat_addresses, 0,
 272                                                thread_index, &eh_key,
 273                                                sm->port_per_thread,
 274                                                tsm->snat_thread_index))
 275         {
 276           b->error = node->errors[NAT_OUT2IN_ED_ERROR_OUT_OF_PORTS];
 277           nat44_delete_session (sm, s, thread_index);
 278           if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &kv, 0))
 279             nat_elog_notice ("out2in-ed key del failed");
 280           return 0;
 281         }
 282       s->ext_host_nat_addr.as_u32 = eh_key.addr.as_u32;
 283       s->ext_host_nat_port = eh_key.port;
 284       s->flags |= SNAT_SESSION_FLAG_TWICE_NAT;
 285       make_ed_kv (&kv, &l_key.addr, &s->ext_host_nat_addr, ip->protocol,
 286                   l_key.fib_index, l_key.port, s->ext_host_nat_port);
 287     }
 288   else
 289     {
 290       make_ed_kv (&kv, &l_key.addr, &s->ext_host_addr, ip->protocol,
 291                   l_key.fib_index, l_key.port, s->ext_host_port);
 292     }
 293   kv.value = s - tsm->sessions;
 294   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->in2out_ed, &kv,
 295                                                nat44_i2o_ed_is_idle_session_cb,
 296                                                &ctx))
 297     nat_elog_notice ("in2out-ed key add failed");
 298
 299   snat_ipfix_logging_nat44_ses_create (thread_index,
 300                                        s->in2out.addr.as_u32,
 301                                        s->out2in.addr.as_u32,
 302                                        s->in2out.protocol,
 303                                        s->in2out.port,
 304                                        s->out2in.port, s->in2out.fib_index);
 305
 306   nat_syslog_nat44_sadd (s->user_index, s->in2out.fib_index,
 307                          &s->in2out.addr, s->in2out.port,
 308                          &s->ext_host_nat_addr, s->ext_host_nat_port,
 309                          &s->out2in.addr, s->out2in.port,
 310                          &s->ext_host_addr, s->ext_host_port,
 311                          s->in2out.protocol, is_twice_nat_session (s));
 312
 313   nat_ha_sadd (&s->in2out.addr, s->in2out.port, &s->out2in.addr,
 314                s->out2in.port, &s->ext_host_addr, s->ext_host_port,
 315                &s->ext_host_nat_addr, s->ext_host_nat_port,
 316                s->in2out.protocol, s->in2out.fib_index, s->flags,
 317                thread_index, 0);
 318
 319   return s;
 320 }
 321
 322 static int
 323 next_src_nat (snat_main_t * sm, ip4_header_t * ip, u8 proto, u16 src_port,
 324               u16 dst_port, u32 thread_index, u32 rx_fib_index)
 325 {
 326   clib_bihash_kv_16_8_t kv, value;
 327   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 328
 329   make_ed_kv (&kv, &ip->src_address, &ip->dst_address, proto,
 330               rx_fib_index, src_port, dst_port);
 331   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 332     return 1;
 333
 334   return 0;
 335 }
 336
 337 static void
 338 create_bypass_for_fwd (snat_main_t * sm, vlib_buffer_t * b, ip4_header_t * ip,
 339                        u32 rx_fib_index, u32 thread_index)
 340 {
 341   nat_ed_ses_key_t key;
 342   clib_bihash_kv_16_8_t kv, value;
 343   udp_header_t *udp;
 344   snat_user_t *u;
 345   snat_session_t *s = 0;
 346   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 347   f64 now = vlib_time_now (sm->vlib_main);
 348
 349   if (ip->protocol == IP_PROTOCOL_ICMP)
 350     {
 351       if (get_icmp_o2i_ed_key (b, ip, &key))
 352         return;
 353     }
 354   else if (ip->protocol == IP_PROTOCOL_UDP || ip->protocol == IP_PROTOCOL_TCP)
 355     {
 356       udp = ip4_next_header (ip);
 357       key.r_addr = ip->src_address;
 358       key.l_addr = ip->dst_address;
 359       key.proto = ip->protocol;
 360       key.l_port = udp->dst_port;
 361       key.r_port = udp->src_port;
 362     }
 363   else
 364     {
 365       key.r_addr = ip->src_address;
 366       key.l_addr = ip->dst_address;
 367       key.proto = ip->protocol;
 368       key.l_port = key.r_port = 0;
 369     }
 370   key.fib_index = 0;
 371   kv.key[0] = key.as_u64[0];
 372   kv.key[1] = key.as_u64[1];
 373
 374   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 375     {
 376       s = pool_elt_at_index (tsm->sessions, value.value);
 377     }
 378   else
 379     {
 380       u32 proto;
 381
 382       if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
 383         return;
 384
 385       u = nat_user_get_or_create (sm, &ip->dst_address, sm->inside_fib_index,
 386                                   thread_index);
 387       if (!u)
 388         {
 389           nat_elog_warn ("create NAT user failed");
 390           return;
 391         }
 392
 393       s = nat_ed_session_alloc (sm, u, thread_index, now);
 394       if (!s)
 395         {
 396           nat44_delete_user_with_no_session (sm, u, thread_index);
 397           nat_elog_warn ("create NAT session failed");
 398           return;
 399         }
 400
 401       proto = ip_proto_to_snat_proto (key.proto);
 402
 403       s->ext_host_addr = key.r_addr;
 404       s->ext_host_port = key.r_port;
 405       s->flags |= SNAT_SESSION_FLAG_FWD_BYPASS;
 406       s->out2in.addr = key.l_addr;
 407       s->out2in.port = key.l_port;
 408       s->out2in.protocol = proto;
 409       if (proto == ~0)
 410         {
 411           s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 412           s->out2in.port = ip->protocol;
 413         }
 414       s->out2in.fib_index = 0;
 415       s->in2out = s->out2in;
 416       user_session_increment (sm, u, 0);
 417
 418       kv.value = s - tsm->sessions;
 419       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &kv, 1))
 420         nat_elog_notice ("in2out_ed key add failed");
 421     }
 422
 423   if (ip->protocol == IP_PROTOCOL_TCP)
 424     {
 425       tcp_header_t *tcp = ip4_next_header (ip);
 426       if (nat44_set_tcp_session_state_o2i
 427           (sm, now, s, tcp->flags, tcp->ack_number, tcp->seq_number,
 428            thread_index))
 429         return;
 430     }
 431
 432   /* Accounting */
 433   nat44_session_update_counters (s, now, 0, thread_index);
 434   /* Per-user LRU list maintenance */
 435   nat44_session_update_lru (sm, s, thread_index);
 436 }
 437
 438 static inline void
 439 create_bypass_for_fwd_worker (snat_main_t * sm, vlib_buffer_t * b,
 440                               ip4_header_t * ip, u32 rx_fib_index)
 441 {
 442   ip4_header_t ip_wkr = {
 443     .src_address = ip->dst_address,
 444   };
 445   u32 thread_index = sm->worker_in2out_cb (&ip_wkr, rx_fib_index, 0);
 446
 447   create_bypass_for_fwd (sm, b, ip, rx_fib_index, thread_index);
 448 }
 449
 450 #ifndef CLIB_MARCH_VARIANT
 451 u32
 452 icmp_match_out2in_ed (snat_main_t * sm, vlib_node_runtime_t * node,
 453                       u32 thread_index, vlib_buffer_t * b, ip4_header_t * ip,
 454                       u8 * p_proto, snat_session_key_t * p_value,
 455                       u8 * p_dont_translate, void *d, void *e)
 456 {
 457   u32 next = ~0, sw_if_index, rx_fib_index;
 458   nat_ed_ses_key_t key;
 459   clib_bihash_kv_16_8_t kv, value;
 460   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 461   snat_session_t *s = 0;
 462   u8 dont_translate = 0, is_addr_only, identity_nat;
 463   snat_session_key_t e_key, l_key;
 464
 465   sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
 466   rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 467
 468   if (get_icmp_o2i_ed_key (b, ip, &key))
 469     {
 470       b->error = node->errors[NAT_OUT2IN_ED_ERROR_UNSUPPORTED_PROTOCOL];
 471       next = NAT_NEXT_DROP;
 472       goto out;
 473     }
 474   key.fib_index = rx_fib_index;
 475   kv.key[0] = key.as_u64[0];
 476   kv.key[1] = key.as_u64[1];
 477
 478   if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv, &value))
 479     {
 480       /* Try to match static mapping */
 481       e_key.addr = ip->dst_address;
 482       e_key.port = key.l_port;
 483       e_key.protocol = ip_proto_to_snat_proto (key.proto);
 484       e_key.fib_index = rx_fib_index;
 485       if (snat_static_mapping_match
 486           (sm, e_key, &l_key, 1, &is_addr_only, 0, 0, 0, &identity_nat))
 487         {
 488           if (!sm->forwarding_enabled)
 489             {
 490               /* Don't NAT packet aimed at the intfc address */
 491               if (PREDICT_FALSE (is_interface_addr (sm, node, sw_if_index,
 492                                                     ip->dst_address.as_u32)))
 493                 {
 494                   dont_translate = 1;
 495                   goto out;
 496                 }
 497               b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 498               next = NAT_NEXT_DROP;
 499               goto out;
 500             }
 501           else
 502             {
 503               dont_translate = 1;
 504               if (next_src_nat (sm, ip, key.proto, key.l_port, key.r_port,
 505                                 thread_index, rx_fib_index))
 506                 {
 507                   next = NAT_NEXT_IN2OUT_ED_FAST_PATH;
 508                   goto out;
 509                 }
 510               if (sm->num_workers > 1)
 511                 create_bypass_for_fwd_worker (sm, b, ip, rx_fib_index);
 512               else
 513                 create_bypass_for_fwd (sm, b, ip, rx_fib_index, thread_index);
 514               goto out;
 515             }
 516         }
 517
 518       if (PREDICT_FALSE
 519           (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 520            ICMP4_echo_reply
 521            && (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 522                ICMP4_echo_request || !is_addr_only)))
 523         {
 524           b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 525           next = NAT_NEXT_DROP;
 526           goto out;
 527         }
 528
 529       if (PREDICT_FALSE (identity_nat))
 530         {
 531           dont_translate = 1;
 532           goto out;
 533         }
 534
 535       /* Create session initiated by host from external network */
 536       s = create_session_for_static_mapping_ed (sm, b, l_key, e_key, node,
 537                                                 thread_index, 0, 0,
 538                                                 vlib_time_now
 539                                                 (sm->vlib_main));
 540
 541       if (!s)
 542         {
 543           next = NAT_NEXT_DROP;
 544           goto out;
 545         }
 546     }
 547   else
 548     {
 549       if (PREDICT_FALSE
 550           (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 551            ICMP4_echo_reply
 552            && vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 553            ICMP4_echo_request
 554            && !icmp_type_is_error_message (vnet_buffer (b)->ip.
 555                                            reass.icmp_type_or_tcp_flags)))
 556         {
 557           b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 558           next = NAT_NEXT_DROP;
 559           goto out;
 560         }
 561
 562       s = pool_elt_at_index (tsm->sessions, value.value);
 563     }
 564
 565   *p_proto = ip_proto_to_snat_proto (key.proto);
 566 out:
 567   if (s)
 568     *p_value = s->in2out;
 569   *p_dont_translate = dont_translate;
 570   if (d)
 571     *(snat_session_t **) d = s;
 572   return next;
 573 }
 574 #endif
 575
 576 static snat_session_t *
 577 nat44_ed_out2in_unknown_proto (snat_main_t * sm,
 578                                vlib_buffer_t * b,
 579                                ip4_header_t * ip,
 580                                u32 rx_fib_index,
 581                                u32 thread_index,
 582                                f64 now,
 583                                vlib_main_t * vm, vlib_node_runtime_t * node)
 584 {
 585   clib_bihash_kv_8_8_t kv, value;
 586   clib_bihash_kv_16_8_t s_kv, s_value;
 587   snat_static_mapping_t *m;
 588   u32 old_addr, new_addr;
 589   ip_csum_t sum;
 590   snat_session_t *s;
 591   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 592   snat_user_t *u;
 593
 594   old_addr = ip->dst_address.as_u32;
 595
 596   make_ed_kv (&s_kv, &ip->dst_address, &ip->src_address, ip->protocol,
 597               rx_fib_index, 0, 0);
 598
 599   if (!clib_bihash_search_16_8 (&tsm->out2in_ed, &s_kv, &s_value))
 600     {
 601       s = pool_elt_at_index (tsm->sessions, s_value.value);
 602       new_addr = ip->dst_address.as_u32 = s->in2out.addr.as_u32;
 603     }
 604   else
 605     {
 606       if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
 607         {
 608           b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 609           nat_elog_notice ("maximum sessions exceeded");
 610           return 0;
 611         }
 612
 613       make_sm_kv (&kv, &ip->dst_address, 0, 0, 0);
 614       if (clib_bihash_search_8_8
 615           (&sm->static_mapping_by_external, &kv, &value))
 616         {
 617           b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 618           return 0;
 619         }
 620
 621       m = pool_elt_at_index (sm->static_mappings, value.value);
 622
 623       new_addr = ip->dst_address.as_u32 = m->local_addr.as_u32;
 624
 625       u = nat_user_get_or_create (sm, &m->local_addr, m->fib_index,
 626                                   thread_index);
 627       if (!u)
 628         {
 629           b->error = node->errors[NAT_OUT2IN_ED_ERROR_CANNOT_CREATE_USER];
 630           nat_elog_warn ("create NAT user failed");
 631           return 0;
 632         }
 633
 634       /* Create a new session */
 635       s = nat_ed_session_alloc (sm, u, thread_index, now);
 636       if (!s)
 637         {
 638           b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_USER_SESS_EXCEEDED];
 639           nat44_delete_user_with_no_session (sm, u, thread_index);
 640           nat_elog_warn ("create NAT session failed");
 641           return 0;
 642         }
 643
 644       s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 645       s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 646       s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 647       s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 648       s->out2in.addr.as_u32 = old_addr;
 649       s->out2in.fib_index = rx_fib_index;
 650       s->in2out.addr.as_u32 = new_addr;
 651       s->in2out.fib_index = m->fib_index;
 652       s->in2out.port = s->out2in.port = ip->protocol;
 653       user_session_increment (sm, u, 1);
 654
 655       /* Add to lookup tables */
 656       s_kv.value = s - tsm->sessions;
 657       if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &s_kv, 1))
 658         nat_elog_notice ("out2in key add failed");
 659
 660       make_ed_kv (&s_kv, &ip->dst_address, &ip->src_address, ip->protocol,
 661                   m->fib_index, 0, 0);
 662       s_kv.value = s - tsm->sessions;
 663       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &s_kv, 1))
 664         nat_elog_notice ("in2out key add failed");
 665     }
 666
 667   /* Update IP checksum */
 668   sum = ip->checksum;
 669   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
 670   ip->checksum = ip_csum_fold (sum);
 671
 672   vnet_buffer (b)->sw_if_index[VLIB_TX] = s->in2out.fib_index;
 673
 674   /* Accounting */
 675   nat44_session_update_counters (s, now, vlib_buffer_length_in_chain (vm, b),
 676                                  thread_index);
 677   /* Per-user LRU list maintenance */
 678   nat44_session_update_lru (sm, s, thread_index);
 679
 680   return s;
 681 }
 682
 683 static inline uword
 684 nat44_ed_out2in_fast_path_node_fn_inline (vlib_main_t * vm,
 685                                           vlib_node_runtime_t * node,
 686                                           vlib_frame_t * frame)
 687 {
 688   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
 689   nat_next_t next_index;
 690   snat_main_t *sm = &snat_main;
 691   f64 now = vlib_time_now (vm);
 692   u32 thread_index = vm->thread_index;
 693   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 694   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 695     0, fragments = 0;
 696   u32 tcp_closed_drops = 0;
 697
 698   stats_node_index = sm->ed_out2in_node_index;
 699
 700   from = vlib_frame_vector_args (frame);
 701   n_left_from = frame->n_vectors;
 702   next_index = node->cached_next_index;
 703
 704   while (n_left_from > 0)
 705     {
 706       u32 n_left_to_next;
 707
 708       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 709
 710       while (n_left_from > 0 && n_left_to_next > 0)
 711         {
 712           u32 bi0;
 713           vlib_buffer_t *b0;
 714           u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
 715             new_addr0;
 716           u16 old_port0, new_port0;
 717           ip4_header_t *ip0;
 718           udp_header_t *udp0;
 719           tcp_header_t *tcp0;
 720           snat_session_t *s0 = 0;
 721           clib_bihash_kv_16_8_t kv0, value0;
 722           ip_csum_t sum0;
 723
 724           /* speculatively enqueue b0 to the current next frame */
 725           bi0 = from[0];
 726           to_next[0] = bi0;
 727           from += 1;
 728           to_next += 1;
 729           n_left_from -= 1;
 730           n_left_to_next -= 1;
 731
 732           b0 = vlib_get_buffer (vm, bi0);
 733           next0 = nat_buffer_opaque (b0)->arc_next;
 734
 735           vnet_buffer (b0)->snat.flags = 0;
 736           ip0 = vlib_buffer_get_current (b0);
 737
 738           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 739           rx_fib_index0 =
 740             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 741                                                  sw_if_index0);
 742
 743           if (PREDICT_FALSE (ip0->ttl == 1))
 744             {
 745               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 746               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 747                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 748                                            0);
 749               next0 = NAT_NEXT_ICMP_ERROR;
 750               goto trace0;
 751             }
 752
 753           udp0 = ip4_next_header (ip0);
 754           tcp0 = (tcp_header_t *) udp0;
 755           proto0 = ip_proto_to_snat_proto (ip0->protocol);
 756
 757           if (PREDICT_FALSE (proto0 == ~0))
 758             {
 759               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 760               goto trace0;
 761             }
 762
 763           if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
 764             {
 765               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 766               goto trace0;
 767             }
 768
 769           make_ed_kv (&kv0, &ip0->dst_address, &ip0->src_address,
 770                       ip0->protocol, rx_fib_index0,
 771                       vnet_buffer (b0)->ip.reass.l4_dst_port,
 772                       vnet_buffer (b0)->ip.reass.l4_src_port);
 773
 774           if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv0, &value0))
 775             {
 776               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 777               goto trace0;
 778             }
 779           s0 = pool_elt_at_index (tsm->sessions, value0.value);
 780
 781           if (s0->tcp_close_timestamp)
 782             {
 783               if (now >= s0->tcp_close_timestamp)
 784                 {
 785                   // session is closed, go slow path
 786                   next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 787                 }
 788               else
 789                 {
 790                   // session in transitory timeout, drop
 791                   b0->error = node->errors[NAT_OUT2IN_ED_ERROR_TCP_CLOSED];
 792                   ++tcp_closed_drops;
 793                   next0 = NAT_NEXT_DROP;
 794                 }
 795               goto trace0;
 796             }
 797
 798           // drop if session expired
 799           u64 sess_timeout_time;
 800           sess_timeout_time = s0->last_heard +
 801             (f64) nat44_session_get_timeout (sm, s0);
 802           if (now >= sess_timeout_time)
 803             {
 804               // delete session
 805               nat_free_session_data (sm, s0, thread_index, 0);
 806               nat44_delete_session (sm, s0, thread_index);
 807
 808               // session no longer exists, go slow path
 809               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 810               goto trace0;
 811             }
 812           //
 813
 814           old_addr0 = ip0->dst_address.as_u32;
 815           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
 816           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
 817
 818           sum0 = ip0->checksum;
 819           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 820                                  dst_address);
 821           if (PREDICT_FALSE (is_twice_nat_session (s0)))
 822             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 823                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
 824                                    src_address);
 825           ip0->checksum = ip_csum_fold (sum0);
 826
 827           old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
 828
 829           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
 830             {
 831               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 832                 {
 833                   new_port0 = udp0->dst_port = s0->in2out.port;
 834                   sum0 = tcp0->checksum;
 835                   sum0 =
 836                     ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 837                                     dst_address);
 838                   sum0 =
 839                     ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 840                                     length);
 841                   if (is_twice_nat_session (s0))
 842                     {
 843                       sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 844                                              s0->ext_host_nat_addr.as_u32,
 845                                              ip4_header_t, dst_address);
 846                       sum0 =
 847                         ip_csum_update (sum0,
 848                                         vnet_buffer (b0)->ip.
 849                                         reass.l4_src_port,
 850                                         s0->ext_host_nat_port, ip4_header_t,
 851                                         length);
 852                       tcp0->src_port = s0->ext_host_nat_port;
 853                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 854                     }
 855                   tcp0->checksum = ip_csum_fold (sum0);
 856                 }
 857               tcp_packets++;
 858               if (nat44_set_tcp_session_state_o2i
 859                   (sm, now, s0,
 860                    vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags,
 861                    vnet_buffer (b0)->ip.reass.tcp_ack_number,
 862                    vnet_buffer (b0)->ip.reass.tcp_seq_number, thread_index))
 863                 goto trace0;
 864             }
 865           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
 866                    && udp0->checksum)
 867             {
 868               new_port0 = udp0->dst_port = s0->in2out.port;
 869               sum0 = udp0->checksum;
 870               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 871                                      dst_address);
 872               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 873                                      length);
 874               if (PREDICT_FALSE (is_twice_nat_session (s0)))
 875                 {
 876                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 877                                          s0->ext_host_nat_addr.as_u32,
 878                                          ip4_header_t, dst_address);
 879                   sum0 =
 880                     ip_csum_update (sum0,
 881                                     vnet_buffer (b0)->ip.reass.l4_src_port,
 882                                     s0->ext_host_nat_port, ip4_header_t,
 883                                     length);
 884                   udp0->src_port = s0->ext_host_nat_port;
 885                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 886                 }
 887               udp0->checksum = ip_csum_fold (sum0);
 888               udp_packets++;
 889             }
 890           else
 891             {
 892               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 893                 {
 894                   new_port0 = udp0->dst_port = s0->in2out.port;
 895                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
 896                     {
 897                       udp0->src_port = s0->ext_host_nat_port;
 898                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 899                     }
 900                 }
 901               udp_packets++;
 902             }
 903
 904           /* Accounting */
 905           nat44_session_update_counters (s0, now,
 906                                          vlib_buffer_length_in_chain (vm, b0),
 907                                          thread_index);
 908           /* Per-user LRU list maintenance */
 909           nat44_session_update_lru (sm, s0, thread_index);
 910
 911         trace0:
 912           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 913                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 914             {
 915               nat44_ed_out2in_trace_t *t =
 916                 vlib_add_trace (vm, node, b0, sizeof (*t));
 917               t->sw_if_index = sw_if_index0;
 918               t->next_index = next0;
 919               t->is_slow_path = 0;
 920
 921               if (s0)
 922                 t->session_index = s0 - tsm->sessions;
 923               else
 924                 t->session_index = ~0;
 925             }
 926
 927           pkts_processed += next0 == nat_buffer_opaque (b0)->arc_next;
 928           /* verify speculative enqueue, maybe switch current next frame */
 929           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 930                                            to_next, n_left_to_next,
 931                                            bi0, next0);
 932         }
 933
 934       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 935     }
 936
 937   vlib_node_increment_counter (vm, stats_node_index,
 938                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
 939                                pkts_processed);
 940   vlib_node_increment_counter (vm, stats_node_index,
 941                                NAT_OUT2IN_ED_ERROR_TCP_PACKETS, tcp_packets);
 942   vlib_node_increment_counter (vm, stats_node_index,
 943                                NAT_OUT2IN_ED_ERROR_UDP_PACKETS, udp_packets);
 944   vlib_node_increment_counter (vm, stats_node_index,
 945                                NAT_OUT2IN_ED_ERROR_ICMP_PACKETS,
 946                                icmp_packets);
 947   vlib_node_increment_counter (vm, stats_node_index,
 948                                NAT_OUT2IN_ED_ERROR_OTHER_PACKETS,
 949                                other_packets);
 950   vlib_node_increment_counter (vm, stats_node_index,
 951                                NAT_OUT2IN_ED_ERROR_FRAGMENTS, fragments);
 952   return frame->n_vectors;
 953 }
 954
 955 static inline uword
 956 nat44_ed_out2in_slow_path_node_fn_inline (vlib_main_t * vm,
 957                                           vlib_node_runtime_t * node,
 958                                           vlib_frame_t * frame)
 959 {
 960   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
 961   nat_next_t next_index;
 962   snat_main_t *sm = &snat_main;
 963   f64 now = vlib_time_now (vm);
 964   u32 thread_index = vm->thread_index;
 965   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 966   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 967     0, fragments = 0;
 968
 969   stats_node_index = sm->ed_out2in_slowpath_node_index;
 970
 971   from = vlib_frame_vector_args (frame);
 972   n_left_from = frame->n_vectors;
 973   next_index = node->cached_next_index;
 974
 975   while (n_left_from > 0)
 976     {
 977       u32 n_left_to_next;
 978
 979       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 980
 981       while (n_left_from > 0 && n_left_to_next > 0)
 982         {
 983           u32 bi0;
 984           vlib_buffer_t *b0;
 985           u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
 986             new_addr0;
 987           u16 old_port0, new_port0;
 988           ip4_header_t *ip0;
 989           udp_header_t *udp0;
 990           tcp_header_t *tcp0;
 991           icmp46_header_t *icmp0;
 992           snat_session_t *s0 = 0;
 993           clib_bihash_kv_16_8_t kv0, value0;
 994           ip_csum_t sum0;
 995           snat_session_key_t e_key0, l_key0;
 996           lb_nat_type_t lb_nat0;
 997           twice_nat_type_t twice_nat0;
 998           u8 identity_nat0;
 999
1000           /* speculatively enqueue b0 to the current next frame */
1001           bi0 = from[0];
1002           to_next[0] = bi0;
1003           from += 1;
1004           to_next += 1;
1005           n_left_from -= 1;
1006           n_left_to_next -= 1;
1007
1008           b0 = vlib_get_buffer (vm, bi0);
1009           next0 = nat_buffer_opaque (b0)->arc_next;
1010
1011           vnet_buffer (b0)->snat.flags = 0;
1012           ip0 = vlib_buffer_get_current (b0);
1013
1014           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1015           rx_fib_index0 =
1016             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
1017                                                  sw_if_index0);
1018
1019           if (PREDICT_FALSE (ip0->ttl == 1))
1020             {
1021               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1022               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1023                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1024                                            0);
1025               next0 = NAT_NEXT_ICMP_ERROR;
1026               goto trace0;
1027             }
1028
1029           udp0 = ip4_next_header (ip0);
1030           tcp0 = (tcp_header_t *) udp0;
1031           icmp0 = (icmp46_header_t *) udp0;
1032           proto0 = ip_proto_to_snat_proto (ip0->protocol);
1033
1034           if (PREDICT_FALSE (proto0 == ~0))
1035             {
1036               s0 =
1037                 nat44_ed_out2in_unknown_proto (sm, b0, ip0, rx_fib_index0,
1038                                                thread_index, now, vm, node);
1039               if (!sm->forwarding_enabled)
1040                 {
1041                   if (!s0)
1042                     next0 = NAT_NEXT_DROP;
1043                 }
1044               other_packets++;
1045               goto trace0;
1046             }
1047
1048           if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1049             {
1050               next0 = icmp_out2in_ed_slow_path
1051                 (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1052                  next0, now, thread_index, &s0);
1053               icmp_packets++;
1054               goto trace0;
1055             }
1056
1057           make_ed_kv (&kv0, &ip0->dst_address, &ip0->src_address,
1058                       ip0->protocol, rx_fib_index0,
1059                       vnet_buffer (b0)->ip.reass.l4_dst_port,
1060                       vnet_buffer (b0)->ip.reass.l4_src_port);
1061
1062           s0 = NULL;
1063           if (!clib_bihash_search_16_8 (&tsm->out2in_ed, &kv0, &value0))
1064             {
1065               s0 = pool_elt_at_index (tsm->sessions, value0.value);
1066
1067               if (s0->tcp_close_timestamp && now >= s0->tcp_close_timestamp)
1068                 {
1069                   nat_free_session_data (sm, s0, thread_index, 0);
1070                   nat44_delete_session (sm, s0, thread_index);
1071                   s0 = NULL;
1072                 }
1073             }
1074
1075           if (!s0)
1076             {
1077               /* Try to match static mapping by external address and port,
1078                  destination address and port in packet */
1079               e_key0.addr = ip0->dst_address;
1080               e_key0.port = vnet_buffer (b0)->ip.reass.l4_dst_port;
1081               e_key0.protocol = proto0;
1082               e_key0.fib_index = rx_fib_index0;
1083
1084               if (snat_static_mapping_match (sm, e_key0, &l_key0, 1, 0,
1085                                              &twice_nat0, &lb_nat0,
1086                                              &ip0->src_address,
1087                                              &identity_nat0))
1088                 {
1089                   /*
1090                    * Send DHCP packets to the ipv4 stack, or we won't
1091                    * be able to use dhcp client on the outside interface
1092                    */
1093                   if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_UDP
1094                                      && (vnet_buffer (b0)->ip.
1095                                          reass.l4_dst_port ==
1096                                          clib_host_to_net_u16
1097                                          (UDP_DST_PORT_dhcp_to_client))))
1098                     {
1099                       goto trace0;
1100                     }
1101
1102                   if (!sm->forwarding_enabled)
1103                     {
1104                       b0->error =
1105                         node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
1106                       next0 = NAT_NEXT_DROP;
1107                     }
1108                   else
1109                     {
1110                       if (next_src_nat (sm, ip0, ip0->protocol,
1111                                         vnet_buffer (b0)->ip.
1112                                         reass.l4_src_port,
1113                                         vnet_buffer (b0)->ip.
1114                                         reass.l4_dst_port, thread_index,
1115                                         rx_fib_index0))
1116                         {
1117                           next0 = NAT_NEXT_IN2OUT_ED_FAST_PATH;
1118                           goto trace0;
1119                         }
1120                       if (sm->num_workers > 1)
1121                         create_bypass_for_fwd_worker (sm, b0, ip0,
1122                                                       rx_fib_index0);
1123                       else
1124                         create_bypass_for_fwd (sm, b0, ip0, rx_fib_index0,
1125                                                thread_index);
1126                     }
1127                   goto trace0;
1128                 }
1129
1130               if (PREDICT_FALSE (identity_nat0))
1131                 goto trace0;
1132
1133               if ((proto0 == SNAT_PROTOCOL_TCP)
1134                   && !tcp_flags_is_init (vnet_buffer (b0)->ip.
1135                                          reass.icmp_type_or_tcp_flags))
1136                 {
1137                   b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
1138                   next0 = NAT_NEXT_DROP;
1139                   goto trace0;
1140                 }
1141
1142               /* Create session initiated by host from external network */
1143               s0 = create_session_for_static_mapping_ed (sm, b0, l_key0,
1144                                                          e_key0, node,
1145                                                          thread_index,
1146                                                          twice_nat0,
1147                                                          lb_nat0, now);
1148               if (!s0)
1149                 {
1150                   next0 = NAT_NEXT_DROP;
1151                   goto trace0;
1152                 }
1153             }
1154
1155           old_addr0 = ip0->dst_address.as_u32;
1156           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
1157           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
1158
1159           sum0 = ip0->checksum;
1160           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1161                                  dst_address);
1162           if (PREDICT_FALSE (is_twice_nat_session (s0)))
1163             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1164                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
1165                                    src_address);
1166           ip0->checksum = ip_csum_fold (sum0);
1167
1168           old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
1169
1170           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
1171             {
1172               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1173                 {
1174                   new_port0 = udp0->dst_port = s0->in2out.port;
1175                   sum0 = tcp0->checksum;
1176                   sum0 =
1177                     ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1178                                     dst_address);
1179                   sum0 =
1180                     ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1181                                     length);
1182                   if (is_twice_nat_session (s0))
1183                     {
1184                       sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1185                                              s0->ext_host_nat_addr.as_u32,
1186                                              ip4_header_t, dst_address);
1187                       sum0 =
1188                         ip_csum_update (sum0,
1189                                         vnet_buffer (b0)->ip.
1190                                         reass.l4_src_port,
1191                                         s0->ext_host_nat_port, ip4_header_t,
1192                                         length);
1193                       tcp0->src_port = s0->ext_host_nat_port;
1194                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1195                     }
1196                   tcp0->checksum = ip_csum_fold (sum0);
1197                 }
1198               tcp_packets++;
1199               if (nat44_set_tcp_session_state_o2i
1200                   (sm, now, s0,
1201                    vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags,
1202                    vnet_buffer (b0)->ip.reass.tcp_ack_number,
1203                    vnet_buffer (b0)->ip.reass.tcp_seq_number, thread_index))
1204                 goto trace0;
1205             }
1206           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
1207                    && udp0->checksum)
1208             {
1209               new_port0 = udp0->dst_port = s0->in2out.port;
1210               sum0 = udp0->checksum;
1211               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1212                                      dst_address);
1213               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1214                                      length);
1215               if (PREDICT_FALSE (is_twice_nat_session (s0)))
1216                 {
1217                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1218                                          s0->ext_host_nat_addr.as_u32,
1219                                          ip4_header_t, dst_address);
1220                   sum0 =
1221                     ip_csum_update (sum0,
1222                                     vnet_buffer (b0)->ip.reass.l4_src_port,
1223                                     s0->ext_host_nat_port, ip4_header_t,
1224                                     length);
1225                   udp0->src_port = s0->ext_host_nat_port;
1226                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1227                 }
1228               udp0->checksum = ip_csum_fold (sum0);
1229               udp_packets++;
1230             }
1231           else
1232             {
1233               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1234                 {
1235                   new_port0 = udp0->dst_port = s0->in2out.port;
1236                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
1237                     {
1238                       udp0->src_port = s0->ext_host_nat_port;
1239                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1240                     }
1241                 }
1242               udp_packets++;
1243             }
1244
1245           /* Accounting */
1246           nat44_session_update_counters (s0, now,
1247                                          vlib_buffer_length_in_chain (vm, b0),
1248                                          thread_index);
1249           /* Per-user LRU list maintenance */
1250           nat44_session_update_lru (sm, s0, thread_index);
1251
1252         trace0:
1253           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1254                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1255             {
1256               nat44_ed_out2in_trace_t *t =
1257                 vlib_add_trace (vm, node, b0, sizeof (*t));
1258               t->sw_if_index = sw_if_index0;
1259               t->next_index = next0;
1260               t->is_slow_path = 1;
1261
1262               if (s0)
1263                 t->session_index = s0 - tsm->sessions;
1264               else
1265                 t->session_index = ~0;
1266             }
1267
1268           pkts_processed += next0 == nat_buffer_opaque (b0)->arc_next;
1269           /* verify speculative enqueue, maybe switch current next frame */
1270           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1271                                            to_next, n_left_to_next,
1272                                            bi0, next0);
1273         }
1274
1275       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1276     }
1277
1278   vlib_node_increment_counter (vm, stats_node_index,
1279                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
1280                                pkts_processed);
1281   vlib_node_increment_counter (vm, stats_node_index,
1282                                NAT_OUT2IN_ED_ERROR_TCP_PACKETS, tcp_packets);
1283   vlib_node_increment_counter (vm, stats_node_index,
1284                                NAT_OUT2IN_ED_ERROR_UDP_PACKETS, udp_packets);
1285   vlib_node_increment_counter (vm, stats_node_index,
1286                                NAT_OUT2IN_ED_ERROR_ICMP_PACKETS,
1287                                icmp_packets);
1288   vlib_node_increment_counter (vm, stats_node_index,
1289                                NAT_OUT2IN_ED_ERROR_OTHER_PACKETS,
1290                                other_packets);
1291   vlib_node_increment_counter (vm, stats_node_index,
1292                                NAT_OUT2IN_ED_ERROR_FRAGMENTS, fragments);
1293   return frame->n_vectors;
1294 }
1295
1296 VLIB_NODE_FN (nat44_ed_out2in_node) (vlib_main_t * vm,
1297                                      vlib_node_runtime_t * node,
1298                                      vlib_frame_t * frame)
1299 {
1300   return nat44_ed_out2in_fast_path_node_fn_inline (vm, node, frame);
1301 }
1302
1303 /* *INDENT-OFF* */
1304 VLIB_REGISTER_NODE (nat44_ed_out2in_node) = {
1305   .name = "nat44-ed-out2in",
1306   .vector_size = sizeof (u32),
1307   .sibling_of = "nat-default",
1308   .format_trace = format_nat44_ed_out2in_trace,
1309   .type = VLIB_NODE_TYPE_INTERNAL,
1310   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1311   .error_strings = nat_out2in_ed_error_strings,
1312   .runtime_data_bytes = sizeof (snat_runtime_t),
1313 };
1314 /* *INDENT-ON* */
1315
1316 VLIB_NODE_FN (nat44_ed_out2in_slowpath_node) (vlib_main_t * vm,
1317                                               vlib_node_runtime_t * node,
1318                                               vlib_frame_t * frame)
1319 {
1320   return nat44_ed_out2in_slow_path_node_fn_inline (vm, node, frame);
1321 }
1322
1323 /* *INDENT-OFF* */
1324 VLIB_REGISTER_NODE (nat44_ed_out2in_slowpath_node) = {
1325   .name = "nat44-ed-out2in-slowpath",
1326   .vector_size = sizeof (u32),
1327   .sibling_of = "nat-default",
1328   .format_trace = format_nat44_ed_out2in_trace,
1329   .type = VLIB_NODE_TYPE_INTERNAL,
1330   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1331   .error_strings = nat_out2in_ed_error_strings,
1332   .runtime_data_bytes = sizeof (snat_runtime_t),
1333 };
1334 /* *INDENT-ON* */
1335
1336 static u8 *
1337 format_nat_pre_trace (u8 * s, va_list * args)
1338 {
1339   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1340   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1341   nat_pre_trace_t *t = va_arg (*args, nat_pre_trace_t *);
1342   return format (s, "out2in next_index %d", t->next_index);
1343 }
1344
1345 VLIB_NODE_FN (nat_pre_out2in_node) (vlib_main_t * vm,
1346                                     vlib_node_runtime_t * node,
1347                                     vlib_frame_t * frame)
1348 {
1349   return nat_pre_node_fn_inline (vm, node, frame,
1350                                  NAT_NEXT_OUT2IN_ED_FAST_PATH);
1351 }
1352
1353 /* *INDENT-OFF* */
1354 VLIB_REGISTER_NODE (nat_pre_out2in_node) = {
1355   .name = "nat-pre-out2in",
1356   .vector_size = sizeof (u32),
1357   .sibling_of = "nat-default",
1358   .format_trace = format_nat_pre_trace,
1359   .type = VLIB_NODE_TYPE_INTERNAL,
1360   .n_errors = 0,
1361  };
1362 /* *INDENT-ON* */
1363
1364 /*
1365  * fd.io coding-style-patch-verification: ON
1366  *
1367  * Local Variables:
1368  * eval: (c-set-style "gnu")
1369  * End:
1370  */