src/plugins/nat/in2out_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 inside to outside 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_in2out_ed_error_strings[] = {
  36 #define _(sym,string) string,
  37   foreach_nat_in2out_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 } nat_in2out_ed_trace_t;
  48
  49 static u8 *
  50 format_nat_in2out_ed_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   nat_in2out_ed_trace_t *t = va_arg (*args, nat_in2out_ed_trace_t *);
  55   char *tag;
  56
  57   tag =
  58     t->is_slow_path ? "NAT44_IN2OUT_ED_SLOW_PATH" :
  59     "NAT44_IN2OUT_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 #ifndef CLIB_MARCH_VARIANT
  68 int
  69 nat44_i2o_ed_is_idle_session_cb (clib_bihash_kv_16_8_t * kv, void *arg)
  70 {
  71   snat_main_t *sm = &snat_main;
  72   nat44_is_idle_session_ctx_t *ctx = arg;
  73   snat_session_t *s;
  74   u64 sess_timeout_time;
  75   nat_ed_ses_key_t ed_key;
  76   clib_bihash_kv_16_8_t ed_kv;
  77   int i;
  78   snat_address_t *a;
  79   snat_session_key_t key;
  80   snat_main_per_thread_data_t *tsm = vec_elt_at_index (sm->per_thread_data,
  81                                                        ctx->thread_index);
  82
  83   s = pool_elt_at_index (tsm->sessions, kv->value);
  84   sess_timeout_time = s->last_heard + (f64) nat44_session_get_timeout (sm, s);
  85   if (ctx->now >= sess_timeout_time)
  86     {
  87       if (is_fwd_bypass_session (s))
  88         goto delete;
  89
  90       ed_key.l_addr = s->out2in.addr;
  91       ed_key.r_addr = s->ext_host_addr;
  92       ed_key.fib_index = s->out2in.fib_index;
  93       if (snat_is_unk_proto_session (s))
  94         {
  95           ed_key.proto = s->in2out.port;
  96           ed_key.r_port = 0;
  97           ed_key.l_port = 0;
  98         }
  99       else
 100         {
 101           ed_key.proto = snat_proto_to_ip_proto (s->in2out.protocol);
 102           ed_key.l_port = s->out2in.port;
 103           ed_key.r_port = s->ext_host_port;
 104         }
 105       ed_kv.key[0] = ed_key.as_u64[0];
 106       ed_kv.key[1] = ed_key.as_u64[1];
 107       if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &ed_kv, 0))
 108         nat_elog_warn ("out2in_ed key del failed");
 109
 110       if (snat_is_unk_proto_session (s))
 111         goto delete;
 112
 113       snat_ipfix_logging_nat44_ses_delete (ctx->thread_index,
 114                                            s->in2out.addr.as_u32,
 115                                            s->out2in.addr.as_u32,
 116                                            s->in2out.protocol,
 117                                            s->in2out.port,
 118                                            s->out2in.port,
 119                                            s->in2out.fib_index);
 120
 121       nat_syslog_nat44_sdel (s->user_index, s->in2out.fib_index,
 122                              &s->in2out.addr, s->in2out.port,
 123                              &s->ext_host_nat_addr, s->ext_host_nat_port,
 124                              &s->out2in.addr, s->out2in.port,
 125                              &s->ext_host_addr, s->ext_host_port,
 126                              s->in2out.protocol, is_twice_nat_session (s));
 127
 128       nat_ha_sdel (&s->out2in.addr, s->out2in.port, &s->ext_host_addr,
 129                    s->ext_host_port, s->out2in.protocol, s->out2in.fib_index,
 130                    ctx->thread_index);
 131
 132       if (is_twice_nat_session (s))
 133         {
 134           for (i = 0; i < vec_len (sm->twice_nat_addresses); i++)
 135             {
 136               key.protocol = s->in2out.protocol;
 137               key.port = s->ext_host_nat_port;
 138               a = sm->twice_nat_addresses + i;
 139               if (a->addr.as_u32 == s->ext_host_nat_addr.as_u32)
 140                 {
 141                   snat_free_outside_address_and_port (sm->twice_nat_addresses,
 142                                                       ctx->thread_index,
 143                                                       &key);
 144                   break;
 145                 }
 146             }
 147         }
 148
 149       if (snat_is_session_static (s))
 150         goto delete;
 151
 152       snat_free_outside_address_and_port (sm->addresses, ctx->thread_index,
 153                                           &s->out2in);
 154     delete:
 155       nat44_delete_session (sm, s, ctx->thread_index);
 156       return 1;
 157     }
 158
 159   return 0;
 160 }
 161 #endif
 162
 163 static inline u32
 164 icmp_in2out_ed_slow_path (snat_main_t * sm, vlib_buffer_t * b0,
 165                           ip4_header_t * ip0, icmp46_header_t * icmp0,
 166                           u32 sw_if_index0, u32 rx_fib_index0,
 167                           vlib_node_runtime_t * node, u32 next0, f64 now,
 168                           u32 thread_index, snat_session_t ** p_s0)
 169 {
 170   next0 = icmp_in2out (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
 171                        next0, thread_index, p_s0, 0);
 172   snat_session_t *s0 = *p_s0;
 173   if (PREDICT_TRUE (next0 != NAT_NEXT_DROP && s0))
 174     {
 175       /* Accounting */
 176       nat44_session_update_counters (s0, now,
 177                                      vlib_buffer_length_in_chain
 178                                      (sm->vlib_main, b0), thread_index);
 179       /* Per-user LRU list maintenance */
 180       nat44_session_update_lru (sm, s0, thread_index);
 181     }
 182   return next0;
 183 }
 184
 185 static u32
 186 slow_path_ed (snat_main_t * sm,
 187               vlib_buffer_t * b,
 188               u32 rx_fib_index,
 189               clib_bihash_kv_16_8_t * kv,
 190               snat_session_t ** sessionp,
 191               vlib_node_runtime_t * node, u32 next, u32 thread_index, f64 now)
 192 {
 193   snat_session_t *s = 0;
 194   snat_user_t *u;
 195   snat_session_key_t key0, key1;
 196   lb_nat_type_t lb = 0, is_sm = 0;
 197   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 198   nat_ed_ses_key_t *key = (nat_ed_ses_key_t *) kv->key;
 199   u32 proto = ip_proto_to_snat_proto (key->proto);
 200   nat_outside_fib_t *outside_fib;
 201   fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
 202   u8 identity_nat;
 203   fib_prefix_t pfx = {
 204     .fp_proto = FIB_PROTOCOL_IP4,
 205     .fp_len = 32,
 206     .fp_addr = {
 207                 .ip4.as_u32 = key->r_addr.as_u32,
 208                 },
 209   };
 210   nat44_is_idle_session_ctx_t ctx;
 211
 212   nat44_session_try_cleanup (&key->l_addr, rx_fib_index, thread_index, now);
 213
 214   if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
 215     {
 216       b->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 217       nat_ipfix_logging_max_sessions (thread_index, sm->max_translations);
 218       nat_elog_notice ("maximum sessions exceeded");
 219       return NAT_NEXT_DROP;
 220     }
 221
 222   key0.addr = key->l_addr;
 223   key0.port = key->l_port;
 224   key1.protocol = key0.protocol = proto;
 225   key0.fib_index = rx_fib_index;
 226   key1.fib_index = sm->outside_fib_index;
 227   /* First try to match static mapping by local address and port */
 228   if (snat_static_mapping_match
 229       (sm, key0, &key1, 0, 0, 0, &lb, 0, &identity_nat))
 230     {
 231       /* Try to create dynamic translation */
 232       if (snat_alloc_outside_address_and_port (sm->addresses, rx_fib_index,
 233                                                thread_index, &key1,
 234                                                sm->port_per_thread,
 235                                                tsm->snat_thread_index))
 236         {
 237           nat_elog_notice ("addresses exhausted");
 238           b->error = node->errors[NAT_IN2OUT_ED_ERROR_OUT_OF_PORTS];
 239           return NAT_NEXT_DROP;
 240         }
 241     }
 242   else
 243     {
 244       if (PREDICT_FALSE (identity_nat))
 245         {
 246           *sessionp = s;
 247           return next;
 248         }
 249
 250       is_sm = 1;
 251     }
 252
 253   if (proto == SNAT_PROTOCOL_TCP)
 254     {
 255       if (!tcp_flags_is_init
 256           (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags))
 257         {
 258           b->error = node->errors[NAT_IN2OUT_ED_ERROR_NON_SYN];
 259           return NAT_NEXT_DROP;
 260         }
 261     }
 262
 263   u = nat_user_get_or_create (sm, &key->l_addr, rx_fib_index, thread_index);
 264   if (!u)
 265     {
 266       nat_elog_warn ("create NAT user failed");
 267       if (!is_sm)
 268         snat_free_outside_address_and_port (sm->addresses,
 269                                             thread_index, &key1);
 270       return NAT_NEXT_DROP;
 271     }
 272
 273   s = nat_ed_session_alloc (sm, u, thread_index, now);
 274   if (!s)
 275     {
 276       nat44_delete_user_with_no_session (sm, u, thread_index);
 277       nat_elog_warn ("create NAT session failed");
 278       if (!is_sm)
 279         snat_free_outside_address_and_port (sm->addresses,
 280                                             thread_index, &key1);
 281       return NAT_NEXT_DROP;
 282     }
 283
 284   user_session_increment (sm, u, is_sm);
 285   if (is_sm)
 286     s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 287   if (lb)
 288     s->flags |= SNAT_SESSION_FLAG_LOAD_BALANCING;
 289   s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 290   s->ext_host_addr = key->r_addr;
 291   s->ext_host_port = key->r_port;
 292   s->in2out = key0;
 293   s->out2in = key1;
 294   s->out2in.protocol = key0.protocol;
 295
 296   switch (vec_len (sm->outside_fibs))
 297     {
 298     case 0:
 299       s->out2in.fib_index = sm->outside_fib_index;
 300       break;
 301     case 1:
 302       s->out2in.fib_index = sm->outside_fibs[0].fib_index;
 303       break;
 304     default:
 305       /* *INDENT-OFF* */
 306       vec_foreach (outside_fib, sm->outside_fibs)
 307        {
 308           fei = fib_table_lookup (outside_fib->fib_index, &pfx);
 309           if (FIB_NODE_INDEX_INVALID != fei)
 310             {
 311               if (fib_entry_get_resolving_interface (fei) != ~0)
 312                 {
 313                   s->out2in.fib_index = outside_fib->fib_index;
 314                   break;
 315                 }
 316             }
 317         }
 318       /* *INDENT-ON* */
 319       break;
 320     }
 321
 322   /* Add to lookup tables */
 323   kv->value = s - tsm->sessions;
 324   ctx.now = now;
 325   ctx.thread_index = thread_index;
 326   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->in2out_ed, kv,
 327                                                nat44_i2o_ed_is_idle_session_cb,
 328                                                &ctx))
 329     nat_elog_notice ("in2out-ed key add failed");
 330
 331   make_ed_kv (kv, &key1.addr, &key->r_addr, key->proto, s->out2in.fib_index,
 332               key1.port, key->r_port);
 333   kv->value = s - tsm->sessions;
 334   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->out2in_ed, kv,
 335                                                nat44_o2i_ed_is_idle_session_cb,
 336                                                &ctx))
 337     nat_elog_notice ("out2in-ed key add failed");
 338
 339   *sessionp = s;
 340
 341   /* log NAT event */
 342   snat_ipfix_logging_nat44_ses_create (thread_index,
 343                                        s->in2out.addr.as_u32,
 344                                        s->out2in.addr.as_u32,
 345                                        s->in2out.protocol,
 346                                        s->in2out.port,
 347                                        s->out2in.port, s->in2out.fib_index);
 348
 349   nat_syslog_nat44_sadd (s->user_index, s->in2out.fib_index,
 350                          &s->in2out.addr, s->in2out.port,
 351                          &s->ext_host_nat_addr, s->ext_host_nat_port,
 352                          &s->out2in.addr, s->out2in.port,
 353                          &s->ext_host_addr, s->ext_host_port,
 354                          s->in2out.protocol, 0);
 355
 356   nat_ha_sadd (&s->in2out.addr, s->in2out.port, &s->out2in.addr,
 357                s->out2in.port, &s->ext_host_addr, s->ext_host_port,
 358                &s->ext_host_nat_addr, s->ext_host_nat_port,
 359                s->in2out.protocol, s->in2out.fib_index, s->flags,
 360                thread_index, 0);
 361
 362   return next;
 363 }
 364
 365 static_always_inline int
 366 nat44_ed_not_translate (snat_main_t * sm, vlib_node_runtime_t * node,
 367                         u32 sw_if_index, ip4_header_t * ip, u32 proto,
 368                         u32 rx_fib_index, u32 thread_index)
 369 {
 370   udp_header_t *udp = ip4_next_header (ip);
 371   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 372   clib_bihash_kv_16_8_t kv, value;
 373   snat_session_key_t key0, key1;
 374
 375   make_ed_kv (&kv, &ip->dst_address, &ip->src_address, ip->protocol,
 376               sm->outside_fib_index, udp->dst_port, udp->src_port);
 377
 378   /* NAT packet aimed at external address if */
 379   /* has active sessions */
 380   if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv, &value))
 381     {
 382       key0.addr = ip->dst_address;
 383       key0.port = udp->dst_port;
 384       key0.protocol = proto;
 385       key0.fib_index = sm->outside_fib_index;
 386       /* or is static mappings */
 387       if (!snat_static_mapping_match (sm, key0, &key1, 1, 0, 0, 0, 0, 0))
 388         return 0;
 389     }
 390   else
 391     return 0;
 392
 393   if (sm->forwarding_enabled)
 394     return 1;
 395
 396   return snat_not_translate_fast (sm, node, sw_if_index, ip, proto,
 397                                   rx_fib_index);
 398 }
 399
 400 static_always_inline int
 401 nat_not_translate_output_feature_fwd (snat_main_t * sm, ip4_header_t * ip,
 402                                       u32 thread_index, f64 now,
 403                                       vlib_main_t * vm, vlib_buffer_t * b)
 404 {
 405   nat_ed_ses_key_t key;
 406   clib_bihash_kv_16_8_t kv, value;
 407   snat_session_t *s = 0;
 408   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 409
 410   if (!sm->forwarding_enabled)
 411     return 0;
 412
 413   if (ip->protocol == IP_PROTOCOL_ICMP)
 414     {
 415       key.as_u64[0] = key.as_u64[1] = 0;
 416       if (get_icmp_i2o_ed_key (b, ip, &key))
 417         return 0;
 418       key.fib_index = 0;
 419       kv.key[0] = key.as_u64[0];
 420       kv.key[1] = key.as_u64[1];
 421     }
 422   else if (ip->protocol == IP_PROTOCOL_UDP || ip->protocol == IP_PROTOCOL_TCP)
 423     {
 424       make_ed_kv (&kv, &ip->src_address, &ip->dst_address, ip->protocol, 0,
 425                   vnet_buffer (b)->ip.reass.l4_src_port,
 426                   vnet_buffer (b)->ip.reass.l4_dst_port);
 427     }
 428   else
 429     {
 430       make_ed_kv (&kv, &ip->src_address, &ip->dst_address, ip->protocol, 0, 0,
 431                   0);
 432     }
 433
 434   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 435     {
 436       s = pool_elt_at_index (tsm->sessions, value.value);
 437       if (is_fwd_bypass_session (s))
 438         {
 439           if (ip->protocol == IP_PROTOCOL_TCP)
 440             {
 441               if (nat44_set_tcp_session_state_i2o (sm, s, b, thread_index))
 442                 return 1;
 443             }
 444           /* Accounting */
 445           nat44_session_update_counters (s, now,
 446                                          vlib_buffer_length_in_chain (vm, b),
 447                                          thread_index);
 448           /* Per-user LRU list maintenance */
 449           nat44_session_update_lru (sm, s, thread_index);
 450           return 1;
 451         }
 452       else
 453         return 0;
 454     }
 455
 456   return 0;
 457 }
 458
 459 static_always_inline int
 460 nat44_ed_not_translate_output_feature (snat_main_t * sm, ip4_header_t * ip,
 461                                        u8 proto, u16 src_port, u16 dst_port,
 462                                        u32 thread_index, u32 rx_sw_if_index,
 463                                        u32 tx_sw_if_index)
 464 {
 465   clib_bihash_kv_16_8_t kv, value;
 466   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 467   snat_interface_t *i;
 468   snat_session_t *s;
 469   u32 rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (rx_sw_if_index);
 470   u32 tx_fib_index = ip4_fib_table_get_index_for_sw_if_index (tx_sw_if_index);
 471
 472   /* src NAT check */
 473   make_ed_kv (&kv, &ip->src_address, &ip->dst_address, proto, tx_fib_index,
 474               src_port, dst_port);
 475   if (!clib_bihash_search_16_8 (&tsm->out2in_ed, &kv, &value))
 476     {
 477       s = pool_elt_at_index (tsm->sessions, value.value);
 478       if (nat44_is_ses_closed (s))
 479         {
 480           nat_free_session_data (sm, s, thread_index, 0);
 481           nat44_delete_session (sm, s, thread_index);
 482         }
 483       else
 484         s->flags |= SNAT_SESSION_FLAG_OUTPUT_FEATURE;
 485       return 1;
 486     }
 487
 488   /* dst NAT check */
 489   make_ed_kv (&kv, &ip->dst_address, &ip->src_address, proto, rx_fib_index,
 490               dst_port, src_port);
 491   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 492     {
 493       s = pool_elt_at_index (tsm->sessions, value.value);
 494       if (is_fwd_bypass_session (s))
 495         return 0;
 496
 497       /* hairpinning */
 498       /* *INDENT-OFF* */
 499       pool_foreach (i, sm->output_feature_interfaces,
 500       ({
 501         if ((nat_interface_is_inside (i)) && (rx_sw_if_index == i->sw_if_index))
 502            return 0;
 503       }));
 504       /* *INDENT-ON* */
 505       return 1;
 506     }
 507
 508   return 0;
 509 }
 510
 511 #ifndef CLIB_MARCH_VARIANT
 512 u32
 513 icmp_match_in2out_ed (snat_main_t * sm, vlib_node_runtime_t * node,
 514                       u32 thread_index, vlib_buffer_t * b, ip4_header_t * ip,
 515                       u8 * p_proto, snat_session_key_t * p_value,
 516                       u8 * p_dont_translate, void *d, void *e)
 517 {
 518   u32 sw_if_index;
 519   u32 rx_fib_index;
 520   nat_ed_ses_key_t key;
 521   snat_session_t *s = 0;
 522   u8 dont_translate = 0;
 523   clib_bihash_kv_16_8_t kv, value;
 524   u32 next = ~0;
 525   int err;
 526   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 527
 528   sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
 529   rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 530
 531   key.as_u64[0] = key.as_u64[1] = 0;
 532   err = get_icmp_i2o_ed_key (b, ip, &key);
 533   if (err != 0)
 534     {
 535       b->error = node->errors[err];
 536       next = NAT_NEXT_DROP;
 537       goto out;
 538     }
 539   key.fib_index = rx_fib_index;
 540
 541   kv.key[0] = key.as_u64[0];
 542   kv.key[1] = key.as_u64[1];
 543
 544   if (clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 545     {
 546       if (vnet_buffer (b)->sw_if_index[VLIB_TX] != ~0)
 547         {
 548           if (PREDICT_FALSE
 549               (nat44_ed_not_translate_output_feature
 550                (sm, ip, key.proto, key.l_port, key.r_port, thread_index,
 551                 sw_if_index, vnet_buffer (b)->sw_if_index[VLIB_TX])))
 552             {
 553               dont_translate = 1;
 554               goto out;
 555             }
 556         }
 557       else
 558         {
 559           if (PREDICT_FALSE (nat44_ed_not_translate (sm, node, sw_if_index,
 560                                                      ip, SNAT_PROTOCOL_ICMP,
 561                                                      rx_fib_index,
 562                                                      thread_index)))
 563             {
 564               dont_translate = 1;
 565               goto out;
 566             }
 567         }
 568
 569       if (PREDICT_FALSE
 570           (icmp_type_is_error_message
 571            (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags)))
 572         {
 573           b->error = node->errors[NAT_IN2OUT_ED_ERROR_BAD_ICMP_TYPE];
 574           next = NAT_NEXT_DROP;
 575           goto out;
 576         }
 577
 578       next = slow_path_ed (sm, b, rx_fib_index, &kv, &s, node, next,
 579                            thread_index, vlib_time_now (sm->vlib_main));
 580
 581       if (PREDICT_FALSE (next == NAT_NEXT_DROP))
 582         goto out;
 583
 584       if (!s)
 585         {
 586           dont_translate = 1;
 587           goto out;
 588         }
 589     }
 590   else
 591     {
 592       if (PREDICT_FALSE
 593           (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 594            ICMP4_echo_request
 595            && vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 596            ICMP4_echo_reply
 597            && !icmp_type_is_error_message (vnet_buffer (b)->ip.
 598                                            reass.icmp_type_or_tcp_flags)))
 599         {
 600           b->error = node->errors[NAT_IN2OUT_ED_ERROR_BAD_ICMP_TYPE];
 601           next = NAT_NEXT_DROP;
 602           goto out;
 603         }
 604
 605       s = pool_elt_at_index (tsm->sessions, value.value);
 606     }
 607
 608   *p_proto = ip_proto_to_snat_proto (key.proto);
 609 out:
 610   if (s)
 611     *p_value = s->out2in;
 612   *p_dont_translate = dont_translate;
 613   if (d)
 614     *(snat_session_t **) d = s;
 615   return next;
 616 }
 617 #endif
 618
 619 static snat_session_t *
 620 nat44_ed_in2out_unknown_proto (snat_main_t * sm,
 621                                vlib_buffer_t * b,
 622                                ip4_header_t * ip,
 623                                u32 rx_fib_index,
 624                                u32 thread_index,
 625                                f64 now,
 626                                vlib_main_t * vm, vlib_node_runtime_t * node)
 627 {
 628   clib_bihash_kv_8_8_t kv, value;
 629   clib_bihash_kv_16_8_t s_kv, s_value;
 630   snat_static_mapping_t *m;
 631   u32 old_addr, new_addr = 0;
 632   ip_csum_t sum;
 633   snat_user_t *u;
 634   dlist_elt_t *head, *elt;
 635   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 636   u32 elt_index, head_index, ses_index;
 637   snat_session_t *s;
 638   u32 outside_fib_index = sm->outside_fib_index;
 639   int i;
 640   u8 is_sm = 0;
 641   nat_outside_fib_t *outside_fib;
 642   fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
 643   fib_prefix_t pfx = {
 644     .fp_proto = FIB_PROTOCOL_IP4,
 645     .fp_len = 32,
 646     .fp_addr = {
 647                 .ip4.as_u32 = ip->dst_address.as_u32,
 648                 },
 649   };
 650
 651   switch (vec_len (sm->outside_fibs))
 652     {
 653     case 0:
 654       outside_fib_index = sm->outside_fib_index;
 655       break;
 656     case 1:
 657       outside_fib_index = sm->outside_fibs[0].fib_index;
 658       break;
 659     default:
 660       /* *INDENT-OFF* */
 661       vec_foreach (outside_fib, sm->outside_fibs)
 662         {
 663           fei = fib_table_lookup (outside_fib->fib_index, &pfx);
 664           if (FIB_NODE_INDEX_INVALID != fei)
 665             {
 666               if (fib_entry_get_resolving_interface (fei) != ~0)
 667                 {
 668                   outside_fib_index = outside_fib->fib_index;
 669                   break;
 670                 }
 671             }
 672         }
 673       /* *INDENT-ON* */
 674       break;
 675     }
 676   old_addr = ip->src_address.as_u32;
 677
 678   make_ed_kv (&s_kv, &ip->src_address, &ip->dst_address, ip->protocol,
 679               rx_fib_index, 0, 0);
 680
 681   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &s_kv, &s_value))
 682     {
 683       s = pool_elt_at_index (tsm->sessions, s_value.value);
 684       new_addr = ip->src_address.as_u32 = s->out2in.addr.as_u32;
 685     }
 686   else
 687     {
 688       if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
 689         {
 690           b->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 691           nat_ipfix_logging_max_sessions (thread_index, sm->max_translations);
 692           nat_elog_notice ("maximum sessions exceeded");
 693           return 0;
 694         }
 695
 696       u = nat_user_get_or_create (sm, &ip->src_address, rx_fib_index,
 697                                   thread_index);
 698       if (!u)
 699         {
 700           nat_elog_warn ("create NAT user failed");
 701           return 0;
 702         }
 703
 704       make_sm_kv (&kv, &ip->src_address, 0, rx_fib_index, 0);
 705
 706       /* Try to find static mapping first */
 707       if (!clib_bihash_search_8_8 (&sm->static_mapping_by_local, &kv, &value))
 708         {
 709           m = pool_elt_at_index (sm->static_mappings, value.value);
 710           new_addr = ip->src_address.as_u32 = m->external_addr.as_u32;
 711           is_sm = 1;
 712           goto create_ses;
 713         }
 714       /* Fallback to 3-tuple key */
 715       else
 716         {
 717           /* Choose same out address as for TCP/UDP session to same destination */
 718           head_index = u->sessions_per_user_list_head_index;
 719           head = pool_elt_at_index (tsm->list_pool, head_index);
 720           elt_index = head->next;
 721           if (PREDICT_FALSE (elt_index == ~0))
 722             ses_index = ~0;
 723           else
 724             {
 725               elt = pool_elt_at_index (tsm->list_pool, elt_index);
 726               ses_index = elt->value;
 727             }
 728
 729           while (ses_index != ~0)
 730             {
 731               s = pool_elt_at_index (tsm->sessions, ses_index);
 732               elt_index = elt->next;
 733               elt = pool_elt_at_index (tsm->list_pool, elt_index);
 734               ses_index = elt->value;
 735
 736               if (s->ext_host_addr.as_u32 == ip->dst_address.as_u32)
 737                 {
 738                   new_addr = ip->src_address.as_u32 = s->out2in.addr.as_u32;
 739
 740                   make_ed_kv (&s_kv, &s->out2in.addr, &ip->dst_address,
 741                               ip->protocol, outside_fib_index, 0, 0);
 742                   if (clib_bihash_search_16_8
 743                       (&tsm->out2in_ed, &s_kv, &s_value))
 744                     goto create_ses;
 745
 746                   break;
 747                 }
 748             }
 749
 750           for (i = 0; i < vec_len (sm->addresses); i++)
 751             {
 752               make_ed_kv (&s_kv, &sm->addresses[i].addr, &ip->dst_address,
 753                           ip->protocol, outside_fib_index, 0, 0);
 754               if (clib_bihash_search_16_8 (&tsm->out2in_ed, &s_kv, &s_value))
 755                 {
 756                   new_addr = ip->src_address.as_u32 =
 757                     sm->addresses[i].addr.as_u32;
 758                   goto create_ses;
 759                 }
 760             }
 761           return 0;
 762         }
 763
 764     create_ses:
 765       s = nat_ed_session_alloc (sm, u, thread_index, now);
 766       if (!s)
 767         {
 768           nat44_delete_user_with_no_session (sm, u, thread_index);
 769           nat_elog_warn ("create NAT session failed");
 770           return 0;
 771         }
 772
 773       s->ext_host_addr.as_u32 = ip->dst_address.as_u32;
 774       s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 775       s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 776       s->out2in.addr.as_u32 = new_addr;
 777       s->out2in.fib_index = outside_fib_index;
 778       s->in2out.addr.as_u32 = old_addr;
 779       s->in2out.fib_index = rx_fib_index;
 780       s->in2out.port = s->out2in.port = ip->protocol;
 781       if (is_sm)
 782         s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 783       user_session_increment (sm, u, is_sm);
 784
 785       /* Add to lookup tables */
 786       make_ed_kv (&s_kv, &s->in2out.addr, &ip->dst_address, ip->protocol,
 787                   rx_fib_index, 0, 0);
 788       s_kv.value = s - tsm->sessions;
 789       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &s_kv, 1))
 790         nat_elog_notice ("in2out key add failed");
 791
 792       make_ed_kv (&s_kv, &s->out2in.addr, &ip->dst_address, ip->protocol,
 793                   outside_fib_index, 0, 0);
 794       s_kv.value = s - tsm->sessions;
 795       if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &s_kv, 1))
 796         nat_elog_notice ("out2in key add failed");
 797     }
 798
 799   /* Update IP checksum */
 800   sum = ip->checksum;
 801   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, src_address);
 802   ip->checksum = ip_csum_fold (sum);
 803
 804   /* Accounting */
 805   nat44_session_update_counters (s, now, vlib_buffer_length_in_chain (vm, b),
 806                                  thread_index);
 807   /* Per-user LRU list maintenance */
 808   nat44_session_update_lru (sm, s, thread_index);
 809
 810   /* Hairpinning */
 811   if (vnet_buffer (b)->sw_if_index[VLIB_TX] == ~0)
 812     nat44_ed_hairpinning_unknown_proto (sm, b, ip);
 813
 814   if (vnet_buffer (b)->sw_if_index[VLIB_TX] == ~0)
 815     vnet_buffer (b)->sw_if_index[VLIB_TX] = outside_fib_index;
 816
 817   return s;
 818 }
 819
 820 static inline uword
 821 nat44_ed_in2out_fast_path_node_fn_inline (vlib_main_t * vm,
 822                                           vlib_node_runtime_t * node,
 823                                           vlib_frame_t * frame,
 824                                           int is_output_feature)
 825 {
 826   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
 827   nat_next_t next_index;
 828   snat_main_t *sm = &snat_main;
 829   f64 now = vlib_time_now (vm);
 830   u32 thread_index = vm->thread_index;
 831   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 832   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 833     0, def_slow;
 834
 835   def_slow = is_output_feature ? NAT_NEXT_IN2OUT_ED_OUTPUT_SLOW_PATH :
 836     NAT_NEXT_IN2OUT_ED_SLOW_PATH;
 837
 838   stats_node_index = sm->ed_in2out_node_index;
 839
 840   from = vlib_frame_vector_args (frame);
 841   n_left_from = frame->n_vectors;
 842   next_index = node->cached_next_index;
 843
 844   while (n_left_from > 0)
 845     {
 846       u32 n_left_to_next;
 847
 848       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 849
 850       while (n_left_from > 0 && n_left_to_next > 0)
 851         {
 852           u32 bi0;
 853           vlib_buffer_t *b0;
 854           u32 next0, sw_if_index0, rx_fib_index0, iph_offset0 = 0, proto0,
 855             new_addr0, old_addr0;
 856           u16 old_port0, new_port0;
 857           ip4_header_t *ip0;
 858           udp_header_t *udp0;
 859           tcp_header_t *tcp0;
 860           snat_session_t *s0 = 0;
 861           clib_bihash_kv_16_8_t kv0, value0;
 862           ip_csum_t sum0;
 863
 864           /* speculatively enqueue b0 to the current next frame */
 865           bi0 = from[0];
 866           to_next[0] = bi0;
 867           from += 1;
 868           to_next += 1;
 869           n_left_from -= 1;
 870           n_left_to_next -= 1;
 871
 872           b0 = vlib_get_buffer (vm, bi0);
 873
 874           if (is_output_feature)
 875             {
 876               vnet_feature_next (&nat_buffer_opaque (b0)->arc_next, b0);
 877               iph_offset0 = vnet_buffer (b0)->ip.reass.save_rewrite_length;
 878             }
 879
 880           next0 = nat_buffer_opaque (b0)->arc_next;
 881
 882           ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
 883                                   iph_offset0);
 884
 885           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 886           rx_fib_index0 =
 887             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 888                                                  sw_if_index0);
 889
 890           if (PREDICT_FALSE (ip0->ttl == 1))
 891             {
 892               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 893               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 894                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 895                                            0);
 896               next0 = NAT_NEXT_ICMP_ERROR;
 897               goto trace0;
 898             }
 899
 900           udp0 = ip4_next_header (ip0);
 901           tcp0 = (tcp_header_t *) udp0;
 902           proto0 = ip_proto_to_snat_proto (ip0->protocol);
 903
 904           if (PREDICT_FALSE (proto0 == ~0))
 905             {
 906               next0 = def_slow;
 907               goto trace0;
 908             }
 909
 910           if (is_output_feature)
 911             {
 912               if (PREDICT_FALSE (nat_not_translate_output_feature_fwd
 913                                  (sm, ip0, thread_index, now, vm, b0)))
 914                 goto trace0;
 915             }
 916
 917           if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
 918             {
 919               next0 = def_slow;
 920               goto trace0;
 921             }
 922
 923           make_ed_kv (&kv0, &ip0->src_address, &ip0->dst_address,
 924                       ip0->protocol, rx_fib_index0,
 925                       vnet_buffer (b0)->ip.reass.l4_src_port,
 926                       vnet_buffer (b0)->ip.reass.l4_dst_port);
 927
 928           // lookup for session
 929           if (clib_bihash_search_16_8 (&tsm->in2out_ed, &kv0, &value0))
 930             {
 931               // session does not exist go slow path
 932               next0 = def_slow;
 933               goto trace0;
 934             }
 935
 936           s0 = pool_elt_at_index (tsm->sessions, value0.value);
 937
 938           b0->flags |= VNET_BUFFER_F_IS_NATED;
 939
 940           if (!is_output_feature)
 941             vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
 942
 943           old_addr0 = ip0->src_address.as_u32;
 944           new_addr0 = ip0->src_address.as_u32 = s0->out2in.addr.as_u32;
 945           sum0 = ip0->checksum;
 946           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 947                                  src_address);
 948           if (PREDICT_FALSE (is_twice_nat_session (s0)))
 949             sum0 = ip_csum_update (sum0, ip0->dst_address.as_u32,
 950                                    s0->ext_host_addr.as_u32, ip4_header_t,
 951                                    dst_address);
 952           ip0->checksum = ip_csum_fold (sum0);
 953
 954           old_port0 = vnet_buffer (b0)->ip.reass.l4_src_port;
 955
 956           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
 957             {
 958               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 959                 {
 960                   new_port0 = udp0->src_port = s0->out2in.port;
 961                   sum0 = tcp0->checksum;
 962                   sum0 =
 963                     ip_csum_update (sum0, old_addr0, new_addr0,
 964                                     ip4_header_t, dst_address);
 965                   sum0 =
 966                     ip_csum_update (sum0, old_port0, new_port0,
 967                                     ip4_header_t, length);
 968                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
 969                     {
 970                       sum0 =
 971                         ip_csum_update (sum0, ip0->dst_address.as_u32,
 972                                         s0->ext_host_addr.as_u32,
 973                                         ip4_header_t, dst_address);
 974                       sum0 =
 975                         ip_csum_update (sum0,
 976                                         vnet_buffer (b0)->ip.
 977                                         reass.l4_dst_port, s0->ext_host_port,
 978                                         ip4_header_t, length);
 979                       tcp0->dst_port = s0->ext_host_port;
 980                       ip0->dst_address.as_u32 = s0->ext_host_addr.as_u32;
 981                     }
 982                   mss_clamping (sm, tcp0, &sum0);
 983                   tcp0->checksum = ip_csum_fold (sum0);
 984                 }
 985               tcp_packets++;
 986               if (nat44_set_tcp_session_state_i2o (sm, s0, b0, thread_index))
 987                 goto trace0;
 988             }
 989           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
 990                    && udp0->checksum)
 991             {
 992               new_port0 = udp0->src_port = s0->out2in.port;
 993               sum0 = udp0->checksum;
 994               sum0 =
 995                 ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 996                                 dst_address);
 997               sum0 =
 998                 ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 999                                 length);
1000               if (PREDICT_FALSE (is_twice_nat_session (s0)))
1001                 {
1002                   sum0 = ip_csum_update (sum0, ip0->dst_address.as_u32,
1003                                          s0->ext_host_addr.as_u32,
1004                                          ip4_header_t, dst_address);
1005                   sum0 =
1006                     ip_csum_update (sum0,
1007                                     vnet_buffer (b0)->ip.reass.l4_dst_port,
1008                                     s0->ext_host_port, ip4_header_t, length);
1009                   udp0->dst_port = s0->ext_host_port;
1010                   ip0->dst_address.as_u32 = s0->ext_host_addr.as_u32;
1011                 }
1012               udp0->checksum = ip_csum_fold (sum0);
1013               udp_packets++;
1014             }
1015           else
1016             {
1017               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1018                 {
1019                   new_port0 = udp0->src_port = s0->out2in.port;
1020                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
1021                     {
1022                       udp0->dst_port = s0->ext_host_port;
1023                       ip0->dst_address.as_u32 = s0->ext_host_addr.as_u32;
1024                     }
1025                   udp_packets++;
1026                 }
1027             }
1028
1029           /* Accounting */
1030           nat44_session_update_counters (s0, now,
1031                                          vlib_buffer_length_in_chain
1032                                          (vm, b0), thread_index);
1033           /* Per-user LRU list maintenance */
1034           nat44_session_update_lru (sm, s0, thread_index);
1035
1036         trace0:
1037           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1038                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1039             {
1040               nat_in2out_ed_trace_t *t =
1041                 vlib_add_trace (vm, node, b0, sizeof (*t));
1042               t->sw_if_index = sw_if_index0;
1043               t->next_index = next0;
1044               t->is_slow_path = 0;
1045
1046               if (s0)
1047                 t->session_index = s0 - tsm->sessions;
1048               else
1049                 t->session_index = ~0;
1050             }
1051
1052           pkts_processed += next0 == nat_buffer_opaque (b0)->arc_next;
1053           /* verify speculative enqueue, maybe switch current next frame */
1054           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1055                                            to_next, n_left_to_next,
1056                                            bi0, next0);
1057         }
1058
1059       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1060     }
1061
1062   vlib_node_increment_counter (vm, stats_node_index,
1063                                NAT_IN2OUT_ED_ERROR_IN2OUT_PACKETS,
1064                                pkts_processed);
1065   vlib_node_increment_counter (vm, stats_node_index,
1066                                NAT_IN2OUT_ED_ERROR_TCP_PACKETS, tcp_packets);
1067   vlib_node_increment_counter (vm, stats_node_index,
1068                                NAT_IN2OUT_ED_ERROR_UDP_PACKETS, udp_packets);
1069   vlib_node_increment_counter (vm, stats_node_index,
1070                                NAT_IN2OUT_ED_ERROR_ICMP_PACKETS,
1071                                icmp_packets);
1072   vlib_node_increment_counter (vm, stats_node_index,
1073                                NAT_IN2OUT_ED_ERROR_OTHER_PACKETS,
1074                                other_packets);
1075   return frame->n_vectors;
1076 }
1077
1078 static inline uword
1079 nat44_ed_in2out_slow_path_node_fn_inline (vlib_main_t * vm,
1080                                           vlib_node_runtime_t * node,
1081                                           vlib_frame_t * frame,
1082                                           int is_output_feature)
1083 {
1084   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
1085   nat_next_t next_index;
1086   snat_main_t *sm = &snat_main;
1087   f64 now = vlib_time_now (vm);
1088   u32 thread_index = vm->thread_index;
1089   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
1090   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets = 0;
1091
1092   stats_node_index = sm->ed_in2out_slowpath_node_index;
1093
1094   from = vlib_frame_vector_args (frame);
1095   n_left_from = frame->n_vectors;
1096   next_index = node->cached_next_index;
1097
1098   while (n_left_from > 0)
1099     {
1100       u32 n_left_to_next;
1101
1102       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1103
1104       while (n_left_from > 0 && n_left_to_next > 0)
1105         {
1106           u32 bi0;
1107           vlib_buffer_t *b0;
1108           u32 next0, sw_if_index0, rx_fib_index0, iph_offset0 = 0, proto0,
1109             new_addr0, old_addr0;
1110           u16 old_port0, new_port0;
1111           ip4_header_t *ip0;
1112           udp_header_t *udp0;
1113           tcp_header_t *tcp0;
1114           icmp46_header_t *icmp0;
1115           snat_session_t *s0 = 0;
1116           clib_bihash_kv_16_8_t kv0, value0;
1117           ip_csum_t sum0;
1118
1119           /* speculatively enqueue b0 to the current next frame */
1120           bi0 = from[0];
1121           to_next[0] = bi0;
1122           from += 1;
1123           to_next += 1;
1124           n_left_from -= 1;
1125           n_left_to_next -= 1;
1126
1127           b0 = vlib_get_buffer (vm, bi0);
1128
1129           if (is_output_feature)
1130             iph_offset0 = vnet_buffer (b0)->ip.reass.save_rewrite_length;
1131
1132           next0 = nat_buffer_opaque (b0)->arc_next;
1133
1134           ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
1135                                   iph_offset0);
1136
1137           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1138           rx_fib_index0 =
1139             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
1140                                                  sw_if_index0);
1141
1142           if (PREDICT_FALSE (ip0->ttl == 1))
1143             {
1144               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1145               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1146                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1147                                            0);
1148               next0 = NAT_NEXT_ICMP_ERROR;
1149               goto trace0;
1150             }
1151
1152           udp0 = ip4_next_header (ip0);
1153           tcp0 = (tcp_header_t *) udp0;
1154           icmp0 = (icmp46_header_t *) udp0;
1155           proto0 = ip_proto_to_snat_proto (ip0->protocol);
1156
1157           if (PREDICT_FALSE (proto0 == ~0))
1158             {
1159               s0 = nat44_ed_in2out_unknown_proto (sm, b0, ip0,
1160                                                   rx_fib_index0,
1161                                                   thread_index, now,
1162                                                   vm, node);
1163               if (!s0)
1164                 next0 = NAT_NEXT_DROP;
1165
1166               other_packets++;
1167               goto trace0;
1168             }
1169
1170           if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1171             {
1172               next0 = icmp_in2out_ed_slow_path
1173                 (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0,
1174                  node, next0, now, thread_index, &s0);
1175               icmp_packets++;
1176               goto trace0;
1177             }
1178
1179           // move down
1180           make_ed_kv (&kv0, &ip0->src_address, &ip0->dst_address,
1181                       ip0->protocol, rx_fib_index0,
1182                       vnet_buffer (b0)->ip.reass.l4_src_port,
1183                       vnet_buffer (b0)->ip.reass.l4_dst_port);
1184
1185           if (clib_bihash_search_16_8 (&tsm->in2out_ed, &kv0, &value0))
1186             {
1187
1188               if (is_output_feature)
1189                 {
1190                   if (PREDICT_FALSE
1191                       (nat44_ed_not_translate_output_feature
1192                        (sm, ip0, ip0->protocol,
1193                         vnet_buffer (b0)->ip.reass.l4_src_port,
1194                         vnet_buffer (b0)->ip.reass.l4_dst_port,
1195                         thread_index, sw_if_index0,
1196                         vnet_buffer (b0)->sw_if_index[VLIB_TX])))
1197                     goto trace0;
1198
1199                   /*
1200                    * Send DHCP packets to the ipv4 stack, or we won't
1201                    * be able to use dhcp client on the outside interface
1202                    */
1203                   if (PREDICT_FALSE
1204                       (proto0 == SNAT_PROTOCOL_UDP
1205                        && (vnet_buffer (b0)->ip.reass.l4_dst_port ==
1206                            clib_host_to_net_u16 (UDP_DST_PORT_dhcp_to_server))
1207                        && ip0->dst_address.as_u32 == 0xffffffff))
1208                     goto trace0;
1209                 }
1210               else
1211                 {
1212                   if (PREDICT_FALSE
1213                       (nat44_ed_not_translate
1214                        (sm, node, sw_if_index0, ip0, proto0, rx_fib_index0,
1215                         thread_index)))
1216                     goto trace0;
1217                 }
1218
1219               next0 = slow_path_ed (sm, b0, rx_fib_index0, &kv0, &s0, node,
1220                                     next0, thread_index, now);
1221
1222               if (PREDICT_FALSE (next0 == NAT_NEXT_DROP))
1223                 goto trace0;
1224
1225               if (PREDICT_FALSE (!s0))
1226                 goto trace0;
1227
1228             }
1229           else
1230             {
1231               s0 = pool_elt_at_index (tsm->sessions, value0.value);
1232             }
1233
1234
1235           b0->flags |= VNET_BUFFER_F_IS_NATED;
1236
1237           if (!is_output_feature)
1238             vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
1239
1240           old_addr0 = ip0->src_address.as_u32;
1241           new_addr0 = ip0->src_address.as_u32 = s0->out2in.addr.as_u32;
1242           sum0 = ip0->checksum;
1243           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1244                                  src_address);
1245           if (PREDICT_FALSE (is_twice_nat_session (s0)))
1246             sum0 = ip_csum_update (sum0, ip0->dst_address.as_u32,
1247                                    s0->ext_host_addr.as_u32, ip4_header_t,
1248                                    dst_address);
1249           ip0->checksum = ip_csum_fold (sum0);
1250
1251           old_port0 = vnet_buffer (b0)->ip.reass.l4_src_port;
1252
1253           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
1254             {
1255               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1256                 {
1257                   new_port0 = udp0->src_port = s0->out2in.port;
1258                   sum0 = tcp0->checksum;
1259                   sum0 =
1260                     ip_csum_update (sum0, old_addr0, new_addr0,
1261                                     ip4_header_t, dst_address);
1262                   sum0 =
1263                     ip_csum_update (sum0, old_port0, new_port0,
1264                                     ip4_header_t, length);
1265                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
1266                     {
1267                       sum0 =
1268                         ip_csum_update (sum0, ip0->dst_address.as_u32,
1269                                         s0->ext_host_addr.as_u32,
1270                                         ip4_header_t, dst_address);
1271                       sum0 =
1272                         ip_csum_update (sum0,
1273                                         vnet_buffer (b0)->ip.
1274                                         reass.l4_dst_port, s0->ext_host_port,
1275                                         ip4_header_t, length);
1276                       tcp0->dst_port = s0->ext_host_port;
1277                       ip0->dst_address.as_u32 = s0->ext_host_addr.as_u32;
1278                     }
1279                   mss_clamping (sm, tcp0, &sum0);
1280                   tcp0->checksum = ip_csum_fold (sum0);
1281                 }
1282               tcp_packets++;
1283               if (nat44_set_tcp_session_state_i2o (sm, s0, b0, thread_index))
1284                 goto trace0;
1285             }
1286           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
1287                    && udp0->checksum)
1288             {
1289               new_port0 = udp0->src_port = s0->out2in.port;
1290               sum0 = udp0->checksum;
1291               sum0 =
1292                 ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1293                                 dst_address);
1294               sum0 =
1295                 ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1296                                 length);
1297               if (PREDICT_FALSE (is_twice_nat_session (s0)))
1298                 {
1299                   sum0 = ip_csum_update (sum0, ip0->dst_address.as_u32,
1300                                          s0->ext_host_addr.as_u32,
1301                                          ip4_header_t, dst_address);
1302                   sum0 =
1303                     ip_csum_update (sum0,
1304                                     vnet_buffer (b0)->ip.reass.l4_dst_port,
1305                                     s0->ext_host_port, ip4_header_t, length);
1306                   udp0->dst_port = s0->ext_host_port;
1307                   ip0->dst_address.as_u32 = s0->ext_host_addr.as_u32;
1308                 }
1309               udp0->checksum = ip_csum_fold (sum0);
1310               udp_packets++;
1311             }
1312           else
1313             {
1314               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1315                 {
1316                   new_port0 = udp0->src_port = s0->out2in.port;
1317                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
1318                     {
1319                       udp0->dst_port = s0->ext_host_port;
1320                       ip0->dst_address.as_u32 = s0->ext_host_addr.as_u32;
1321                     }
1322                   udp_packets++;
1323                 }
1324             }
1325
1326           /* Accounting */
1327           nat44_session_update_counters (s0, now,
1328                                          vlib_buffer_length_in_chain
1329                                          (vm, b0), thread_index);
1330           /* Per-user LRU list maintenance */
1331           nat44_session_update_lru (sm, s0, thread_index);
1332
1333         trace0:
1334           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1335                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1336             {
1337               nat_in2out_ed_trace_t *t =
1338                 vlib_add_trace (vm, node, b0, sizeof (*t));
1339               t->sw_if_index = sw_if_index0;
1340               t->next_index = next0;
1341               t->is_slow_path = 1;
1342
1343               if (s0)
1344                 t->session_index = s0 - tsm->sessions;
1345               else
1346                 t->session_index = ~0;
1347             }
1348
1349           pkts_processed += next0 == nat_buffer_opaque (b0)->arc_next;
1350
1351           /* verify speculative enqueue, maybe switch current next frame */
1352           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1353                                            to_next, n_left_to_next,
1354                                            bi0, next0);
1355         }
1356
1357       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1358     }
1359
1360   vlib_node_increment_counter (vm, stats_node_index,
1361                                NAT_IN2OUT_ED_ERROR_IN2OUT_PACKETS,
1362                                pkts_processed);
1363   vlib_node_increment_counter (vm, stats_node_index,
1364                                NAT_IN2OUT_ED_ERROR_TCP_PACKETS, tcp_packets);
1365   vlib_node_increment_counter (vm, stats_node_index,
1366                                NAT_IN2OUT_ED_ERROR_UDP_PACKETS, udp_packets);
1367   vlib_node_increment_counter (vm, stats_node_index,
1368                                NAT_IN2OUT_ED_ERROR_ICMP_PACKETS,
1369                                icmp_packets);
1370   vlib_node_increment_counter (vm, stats_node_index,
1371                                NAT_IN2OUT_ED_ERROR_OTHER_PACKETS,
1372                                other_packets);
1373   return frame->n_vectors;
1374 }
1375
1376 VLIB_NODE_FN (nat44_ed_in2out_node) (vlib_main_t * vm,
1377                                      vlib_node_runtime_t * node,
1378                                      vlib_frame_t * frame)
1379 {
1380   return nat44_ed_in2out_fast_path_node_fn_inline (vm, node, frame, 0);
1381 }
1382
1383 /* *INDENT-OFF* */
1384 VLIB_REGISTER_NODE (nat44_ed_in2out_node) = {
1385   .name = "nat44-ed-in2out",
1386   .vector_size = sizeof (u32),
1387   .sibling_of = "nat-default",
1388   .format_trace = format_nat_in2out_ed_trace,
1389   .type = VLIB_NODE_TYPE_INTERNAL,
1390   .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
1391   .error_strings = nat_in2out_ed_error_strings,
1392   .runtime_data_bytes = sizeof (snat_runtime_t),
1393 };
1394 /* *INDENT-ON* */
1395
1396 VLIB_NODE_FN (nat44_ed_in2out_output_node) (vlib_main_t * vm,
1397                                             vlib_node_runtime_t * node,
1398                                             vlib_frame_t * frame)
1399 {
1400   return nat44_ed_in2out_fast_path_node_fn_inline (vm, node, frame, 1);
1401 }
1402
1403 /* *INDENT-OFF* */
1404 VLIB_REGISTER_NODE (nat44_ed_in2out_output_node) = {
1405   .name = "nat44-ed-in2out-output",
1406   .vector_size = sizeof (u32),
1407   .sibling_of = "nat-default",
1408   .format_trace = format_nat_in2out_ed_trace,
1409   .type = VLIB_NODE_TYPE_INTERNAL,
1410   .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
1411   .error_strings = nat_in2out_ed_error_strings,
1412   .runtime_data_bytes = sizeof (snat_runtime_t),
1413 };
1414 /* *INDENT-ON* */
1415
1416 VLIB_NODE_FN (nat44_ed_in2out_slowpath_node) (vlib_main_t * vm,
1417                                               vlib_node_runtime_t *
1418                                               node, vlib_frame_t * frame)
1419 {
1420   return nat44_ed_in2out_slow_path_node_fn_inline (vm, node, frame, 0);
1421 }
1422
1423 /* *INDENT-OFF* */
1424 VLIB_REGISTER_NODE (nat44_ed_in2out_slowpath_node) = {
1425   .name = "nat44-ed-in2out-slowpath",
1426   .vector_size = sizeof (u32),
1427   .sibling_of = "nat-default",
1428   .format_trace = format_nat_in2out_ed_trace,
1429   .type = VLIB_NODE_TYPE_INTERNAL,
1430   .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
1431   .error_strings = nat_in2out_ed_error_strings,
1432   .runtime_data_bytes = sizeof (snat_runtime_t),
1433 };
1434 /* *INDENT-ON* */
1435
1436 VLIB_NODE_FN (nat44_ed_in2out_output_slowpath_node) (vlib_main_t * vm,
1437                                                      vlib_node_runtime_t
1438                                                      * node,
1439                                                      vlib_frame_t * frame)
1440 {
1441   return nat44_ed_in2out_slow_path_node_fn_inline (vm, node, frame, 1);
1442 }
1443
1444 /* *INDENT-OFF* */
1445 VLIB_REGISTER_NODE (nat44_ed_in2out_output_slowpath_node) = {
1446   .name = "nat44-ed-in2out-output-slowpath",
1447   .vector_size = sizeof (u32),
1448   .sibling_of = "nat-default",
1449   .format_trace = format_nat_in2out_ed_trace,
1450   .type = VLIB_NODE_TYPE_INTERNAL,
1451   .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
1452   .error_strings = nat_in2out_ed_error_strings,
1453   .runtime_data_bytes = sizeof (snat_runtime_t),
1454 };
1455 /* *INDENT-ON* */
1456
1457 static u8 *
1458 format_nat_pre_trace (u8 * s, va_list * args)
1459 {
1460   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1461   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1462   nat_pre_trace_t *t = va_arg (*args, nat_pre_trace_t *);
1463   return format (s, "in2out next_index %d", t->next_index);
1464 }
1465
1466 VLIB_NODE_FN (nat_pre_in2out_node)
1467   (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
1468 {
1469   return nat_pre_node_fn_inline (vm, node, frame,
1470                                  NAT_NEXT_IN2OUT_ED_FAST_PATH);
1471 }
1472
1473 /* *INDENT-OFF* */
1474 VLIB_REGISTER_NODE (nat_pre_in2out_node) = {
1475   .name = "nat-pre-in2out",
1476   .vector_size = sizeof (u32),
1477   .sibling_of = "nat-default",
1478   .format_trace = format_nat_pre_trace,
1479   .type = VLIB_NODE_TYPE_INTERNAL,
1480   .n_errors = 0,
1481 };
1482 /* *INDENT-ON* */
1483
1484 /*
1485  * fd.io coding-style-patch-verification: ON
1486  *
1487  * Local Variables:
1488  * eval: (c-set-style "gnu")
1489  * End:
1490  */