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   u32 cleared = 0;
 213
 214   if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
 215     {
 216       if (PREDICT_FALSE
 217           (!(cleared = nat44_users_cleanup (thread_index, now))))
 218         {
 219           b->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 220           nat_ipfix_logging_max_sessions (thread_index, sm->max_translations);
 221           nat_elog_notice ("maximum sessions exceeded");
 222           return NAT_NEXT_DROP;
 223         }
 224     }
 225
 226   key0.addr = key->l_addr;
 227   key0.port = key->l_port;
 228   key1.protocol = key0.protocol = proto;
 229   key0.fib_index = rx_fib_index;
 230   key1.fib_index = sm->outside_fib_index;
 231
 232   /* First try to match static mapping by local address and port */
 233   if (snat_static_mapping_match
 234       (sm, key0, &key1, 0, 0, 0, &lb, 0, &identity_nat))
 235     {
 236       /* Try to create dynamic translation */
 237       if (snat_alloc_outside_address_and_port (sm->addresses, rx_fib_index,
 238                                                thread_index, &key1,
 239                                                sm->port_per_thread,
 240                                                tsm->snat_thread_index))
 241         {
 242           if (cleared || !nat44_out_of_ports_cleanup (thread_index, now) ||
 243               snat_alloc_outside_address_and_port (sm->addresses,
 244                                                    rx_fib_index, thread_index,
 245                                                    &key1, sm->port_per_thread,
 246                                                    tsm->snat_thread_index))
 247             {
 248               nat_elog_notice ("addresses exhausted");
 249               b->error = node->errors[NAT_IN2OUT_ED_ERROR_OUT_OF_PORTS];
 250               return NAT_NEXT_DROP;
 251             }
 252         }
 253     }
 254   else
 255     {
 256       if (PREDICT_FALSE (identity_nat))
 257         {
 258           *sessionp = s;
 259           return next;
 260         }
 261       is_sm = 1;
 262     }
 263
 264   if (PREDICT_TRUE (proto == SNAT_PROTOCOL_TCP))
 265     {
 266       if (PREDICT_FALSE
 267           (!tcp_flags_is_init
 268            (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags)))
 269         {
 270           b->error = node->errors[NAT_IN2OUT_ED_ERROR_NON_SYN];
 271           if (!is_sm)
 272             snat_free_outside_address_and_port (sm->addresses,
 273                                                 thread_index, &key1);
 274           return NAT_NEXT_DROP;
 275         }
 276     }
 277
 278   u = nat_user_get_or_create (sm, &key->l_addr, rx_fib_index, thread_index);
 279   if (!u)
 280     {
 281       nat_elog_warn ("create NAT user failed");
 282       if (!is_sm)
 283         snat_free_outside_address_and_port (sm->addresses,
 284                                             thread_index, &key1);
 285       b->error = node->errors[NAT_IN2OUT_ED_ERROR_CANNOT_CREATE_USER];
 286       return NAT_NEXT_DROP;
 287     }
 288
 289   s = nat_ed_session_alloc (sm, u, thread_index, now);
 290   if (!s)
 291     {
 292       nat44_delete_user_with_no_session (sm, u, thread_index);
 293       nat_elog_warn ("create NAT session failed");
 294       if (!is_sm)
 295         snat_free_outside_address_and_port (sm->addresses,
 296                                             thread_index, &key1);
 297       b->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_USER_SESS_EXCEEDED];
 298       return NAT_NEXT_DROP;
 299     }
 300
 301   user_session_increment (sm, u, is_sm);
 302   if (is_sm)
 303     s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 304   if (lb)
 305     s->flags |= SNAT_SESSION_FLAG_LOAD_BALANCING;
 306   s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 307   s->ext_host_addr = key->r_addr;
 308   s->ext_host_port = key->r_port;
 309   s->in2out = key0;
 310   s->out2in = key1;
 311   s->out2in.protocol = key0.protocol;
 312
 313   switch (vec_len (sm->outside_fibs))
 314     {
 315     case 0:
 316       s->out2in.fib_index = sm->outside_fib_index;
 317       break;
 318     case 1:
 319       s->out2in.fib_index = sm->outside_fibs[0].fib_index;
 320       break;
 321     default:
 322       /* *INDENT-OFF* */
 323       vec_foreach (outside_fib, sm->outside_fibs)
 324        {
 325           fei = fib_table_lookup (outside_fib->fib_index, &pfx);
 326           if (FIB_NODE_INDEX_INVALID != fei)
 327             {
 328               if (fib_entry_get_resolving_interface (fei) != ~0)
 329                 {
 330                   s->out2in.fib_index = outside_fib->fib_index;
 331                   break;
 332                 }
 333             }
 334         }
 335       /* *INDENT-ON* */
 336       break;
 337     }
 338
 339   /* Add to lookup tables */
 340   kv->value = s - tsm->sessions;
 341   ctx.now = now;
 342   ctx.thread_index = thread_index;
 343   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->in2out_ed, kv,
 344                                                nat44_i2o_ed_is_idle_session_cb,
 345                                                &ctx))
 346     nat_elog_notice ("in2out-ed key add failed");
 347
 348   make_ed_kv (kv, &key1.addr, &key->r_addr, key->proto, s->out2in.fib_index,
 349               key1.port, key->r_port);
 350   kv->value = s - tsm->sessions;
 351   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->out2in_ed, kv,
 352                                                nat44_o2i_ed_is_idle_session_cb,
 353                                                &ctx))
 354     nat_elog_notice ("out2in-ed key add failed");
 355
 356   *sessionp = s;
 357
 358   /* log NAT event */
 359   snat_ipfix_logging_nat44_ses_create (thread_index,
 360                                        s->in2out.addr.as_u32,
 361                                        s->out2in.addr.as_u32,
 362                                        s->in2out.protocol,
 363                                        s->in2out.port,
 364                                        s->out2in.port, s->in2out.fib_index);
 365
 366   nat_syslog_nat44_sadd (s->user_index, s->in2out.fib_index,
 367                          &s->in2out.addr, s->in2out.port,
 368                          &s->ext_host_nat_addr, s->ext_host_nat_port,
 369                          &s->out2in.addr, s->out2in.port,
 370                          &s->ext_host_addr, s->ext_host_port,
 371                          s->in2out.protocol, 0);
 372
 373   nat_ha_sadd (&s->in2out.addr, s->in2out.port, &s->out2in.addr,
 374                s->out2in.port, &s->ext_host_addr, s->ext_host_port,
 375                &s->ext_host_nat_addr, s->ext_host_nat_port,
 376                s->in2out.protocol, s->in2out.fib_index, s->flags,
 377                thread_index, 0);
 378
 379   return next;
 380 }
 381
 382 static_always_inline int
 383 nat44_ed_not_translate (snat_main_t * sm, vlib_node_runtime_t * node,
 384                         u32 sw_if_index, ip4_header_t * ip, u32 proto,
 385                         u32 rx_fib_index, u32 thread_index)
 386 {
 387   udp_header_t *udp = ip4_next_header (ip);
 388   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 389   clib_bihash_kv_16_8_t kv, value;
 390   snat_session_key_t key0, key1;
 391
 392   make_ed_kv (&kv, &ip->dst_address, &ip->src_address, ip->protocol,
 393               sm->outside_fib_index, udp->dst_port, udp->src_port);
 394
 395   /* NAT packet aimed at external address if */
 396   /* has active sessions */
 397   if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv, &value))
 398     {
 399       key0.addr = ip->dst_address;
 400       key0.port = udp->dst_port;
 401       key0.protocol = proto;
 402       key0.fib_index = sm->outside_fib_index;
 403       /* or is static mappings */
 404       if (!snat_static_mapping_match (sm, key0, &key1, 1, 0, 0, 0, 0, 0))
 405         return 0;
 406     }
 407   else
 408     return 0;
 409
 410   if (sm->forwarding_enabled)
 411     return 1;
 412
 413   return snat_not_translate_fast (sm, node, sw_if_index, ip, proto,
 414                                   rx_fib_index);
 415 }
 416
 417 static_always_inline int
 418 nat_not_translate_output_feature_fwd (snat_main_t * sm, ip4_header_t * ip,
 419                                       u32 thread_index, f64 now,
 420                                       vlib_main_t * vm, vlib_buffer_t * b)
 421 {
 422   nat_ed_ses_key_t key;
 423   clib_bihash_kv_16_8_t kv, value;
 424   snat_session_t *s = 0;
 425   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 426
 427   if (!sm->forwarding_enabled)
 428     return 0;
 429
 430   if (ip->protocol == IP_PROTOCOL_ICMP)
 431     {
 432       key.as_u64[0] = key.as_u64[1] = 0;
 433       if (get_icmp_i2o_ed_key (b, ip, &key))
 434         return 0;
 435       key.fib_index = 0;
 436       kv.key[0] = key.as_u64[0];
 437       kv.key[1] = key.as_u64[1];
 438     }
 439   else if (ip->protocol == IP_PROTOCOL_UDP || ip->protocol == IP_PROTOCOL_TCP)
 440     {
 441       make_ed_kv (&kv, &ip->src_address, &ip->dst_address, ip->protocol, 0,
 442                   vnet_buffer (b)->ip.reass.l4_src_port,
 443                   vnet_buffer (b)->ip.reass.l4_dst_port);
 444     }
 445   else
 446     {
 447       make_ed_kv (&kv, &ip->src_address, &ip->dst_address, ip->protocol, 0, 0,
 448                   0);
 449     }
 450
 451   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 452     {
 453       s = pool_elt_at_index (tsm->sessions, value.value);
 454       if (is_fwd_bypass_session (s))
 455         {
 456           if (ip->protocol == IP_PROTOCOL_TCP)
 457             {
 458               if (nat44_set_tcp_session_state_i2o (sm, s, b, thread_index))
 459                 return 1;
 460             }
 461           /* Accounting */
 462           nat44_session_update_counters (s, now,
 463                                          vlib_buffer_length_in_chain (vm, b),
 464                                          thread_index);
 465           /* Per-user LRU list maintenance */
 466           nat44_session_update_lru (sm, s, thread_index);
 467           return 1;
 468         }
 469       else
 470         return 0;
 471     }
 472
 473   return 0;
 474 }
 475
 476 static_always_inline int
 477 nat44_ed_not_translate_output_feature (snat_main_t * sm, ip4_header_t * ip,
 478                                        u8 proto, u16 src_port, u16 dst_port,
 479                                        u32 thread_index, u32 rx_sw_if_index,
 480                                        u32 tx_sw_if_index)
 481 {
 482   clib_bihash_kv_16_8_t kv, value;
 483   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 484   snat_interface_t *i;
 485   snat_session_t *s;
 486   u32 rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (rx_sw_if_index);
 487   u32 tx_fib_index = ip4_fib_table_get_index_for_sw_if_index (tx_sw_if_index);
 488
 489   /* src NAT check */
 490   make_ed_kv (&kv, &ip->src_address, &ip->dst_address, proto, tx_fib_index,
 491               src_port, dst_port);
 492   if (!clib_bihash_search_16_8 (&tsm->out2in_ed, &kv, &value))
 493     {
 494       s = pool_elt_at_index (tsm->sessions, value.value);
 495       if (nat44_is_ses_closed (s))
 496         {
 497           nat_free_session_data (sm, s, thread_index, 0);
 498           nat44_delete_session (sm, s, thread_index);
 499         }
 500       else
 501         s->flags |= SNAT_SESSION_FLAG_OUTPUT_FEATURE;
 502       return 1;
 503     }
 504
 505   /* dst NAT check */
 506   make_ed_kv (&kv, &ip->dst_address, &ip->src_address, proto, rx_fib_index,
 507               dst_port, src_port);
 508   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 509     {
 510       s = pool_elt_at_index (tsm->sessions, value.value);
 511       if (is_fwd_bypass_session (s))
 512         return 0;
 513
 514       /* hairpinning */
 515       /* *INDENT-OFF* */
 516       pool_foreach (i, sm->output_feature_interfaces,
 517       ({
 518         if ((nat_interface_is_inside (i)) && (rx_sw_if_index == i->sw_if_index))
 519            return 0;
 520       }));
 521       /* *INDENT-ON* */
 522       return 1;
 523     }
 524
 525   return 0;
 526 }
 527
 528 #ifndef CLIB_MARCH_VARIANT
 529 u32
 530 icmp_match_in2out_ed (snat_main_t * sm, vlib_node_runtime_t * node,
 531                       u32 thread_index, vlib_buffer_t * b, ip4_header_t * ip,
 532                       u8 * p_proto, snat_session_key_t * p_value,
 533                       u8 * p_dont_translate, void *d, void *e)
 534 {
 535   u32 sw_if_index;
 536   u32 rx_fib_index;
 537   nat_ed_ses_key_t key;
 538   snat_session_t *s = 0;
 539   u8 dont_translate = 0;
 540   clib_bihash_kv_16_8_t kv, value;
 541   u32 next = ~0;
 542   int err;
 543   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 544
 545   sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
 546   rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 547
 548   key.as_u64[0] = key.as_u64[1] = 0;
 549   err = get_icmp_i2o_ed_key (b, ip, &key);
 550   if (err != 0)
 551     {
 552       b->error = node->errors[err];
 553       next = NAT_NEXT_DROP;
 554       goto out;
 555     }
 556   key.fib_index = rx_fib_index;
 557
 558   kv.key[0] = key.as_u64[0];
 559   kv.key[1] = key.as_u64[1];
 560
 561   if (clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 562     {
 563       if (vnet_buffer (b)->sw_if_index[VLIB_TX] != ~0)
 564         {
 565           if (PREDICT_FALSE
 566               (nat44_ed_not_translate_output_feature
 567                (sm, ip, key.proto, key.l_port, key.r_port, thread_index,
 568                 sw_if_index, vnet_buffer (b)->sw_if_index[VLIB_TX])))
 569             {
 570               dont_translate = 1;
 571               goto out;
 572             }
 573         }
 574       else
 575         {
 576           if (PREDICT_FALSE (nat44_ed_not_translate (sm, node, sw_if_index,
 577                                                      ip, SNAT_PROTOCOL_ICMP,
 578                                                      rx_fib_index,
 579                                                      thread_index)))
 580             {
 581               dont_translate = 1;
 582               goto out;
 583             }
 584         }
 585
 586       if (PREDICT_FALSE
 587           (icmp_type_is_error_message
 588            (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags)))
 589         {
 590           b->error = node->errors[NAT_IN2OUT_ED_ERROR_BAD_ICMP_TYPE];
 591           next = NAT_NEXT_DROP;
 592           goto out;
 593         }
 594
 595       next = slow_path_ed (sm, b, rx_fib_index, &kv, &s, node, next,
 596                            thread_index, vlib_time_now (sm->vlib_main));
 597
 598       if (PREDICT_FALSE (next == NAT_NEXT_DROP))
 599         goto out;
 600
 601       if (!s)
 602         {
 603           dont_translate = 1;
 604           goto out;
 605         }
 606     }
 607   else
 608     {
 609       if (PREDICT_FALSE
 610           (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 611            ICMP4_echo_request
 612            && vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 613            ICMP4_echo_reply
 614            && !icmp_type_is_error_message (vnet_buffer (b)->ip.
 615                                            reass.icmp_type_or_tcp_flags)))
 616         {
 617           b->error = node->errors[NAT_IN2OUT_ED_ERROR_BAD_ICMP_TYPE];
 618           next = NAT_NEXT_DROP;
 619           goto out;
 620         }
 621
 622       s = pool_elt_at_index (tsm->sessions, value.value);
 623     }
 624
 625   *p_proto = ip_proto_to_snat_proto (key.proto);
 626 out:
 627   if (s)
 628     *p_value = s->out2in;
 629   *p_dont_translate = dont_translate;
 630   if (d)
 631     *(snat_session_t **) d = s;
 632   return next;
 633 }
 634 #endif
 635
 636 static snat_session_t *
 637 nat44_ed_in2out_unknown_proto (snat_main_t * sm,
 638                                vlib_buffer_t * b,
 639                                ip4_header_t * ip,
 640                                u32 rx_fib_index,
 641                                u32 thread_index,
 642                                f64 now,
 643                                vlib_main_t * vm, vlib_node_runtime_t * node)
 644 {
 645   clib_bihash_kv_8_8_t kv, value;
 646   clib_bihash_kv_16_8_t s_kv, s_value;
 647   snat_static_mapping_t *m;
 648   u32 old_addr, new_addr = 0;
 649   ip_csum_t sum;
 650   snat_user_t *u;
 651   dlist_elt_t *head, *elt;
 652   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 653   u32 elt_index, head_index, ses_index;
 654   snat_session_t *s;
 655   u32 outside_fib_index = sm->outside_fib_index;
 656   int i;
 657   u8 is_sm = 0;
 658   nat_outside_fib_t *outside_fib;
 659   fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
 660   fib_prefix_t pfx = {
 661     .fp_proto = FIB_PROTOCOL_IP4,
 662     .fp_len = 32,
 663     .fp_addr = {
 664                 .ip4.as_u32 = ip->dst_address.as_u32,
 665                 },
 666   };
 667
 668   switch (vec_len (sm->outside_fibs))
 669     {
 670     case 0:
 671       outside_fib_index = sm->outside_fib_index;
 672       break;
 673     case 1:
 674       outside_fib_index = sm->outside_fibs[0].fib_index;
 675       break;
 676     default:
 677       /* *INDENT-OFF* */
 678       vec_foreach (outside_fib, sm->outside_fibs)
 679         {
 680           fei = fib_table_lookup (outside_fib->fib_index, &pfx);
 681           if (FIB_NODE_INDEX_INVALID != fei)
 682             {
 683               if (fib_entry_get_resolving_interface (fei) != ~0)
 684                 {
 685                   outside_fib_index = outside_fib->fib_index;
 686                   break;
 687                 }
 688             }
 689         }
 690       /* *INDENT-ON* */
 691       break;
 692     }
 693   old_addr = ip->src_address.as_u32;
 694
 695   make_ed_kv (&s_kv, &ip->src_address, &ip->dst_address, ip->protocol,
 696               rx_fib_index, 0, 0);
 697
 698   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &s_kv, &s_value))
 699     {
 700       s = pool_elt_at_index (tsm->sessions, s_value.value);
 701       new_addr = ip->src_address.as_u32 = s->out2in.addr.as_u32;
 702     }
 703   else
 704     {
 705       if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
 706         {
 707           b->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 708           nat_ipfix_logging_max_sessions (thread_index, sm->max_translations);
 709           nat_elog_notice ("maximum sessions exceeded");
 710           return 0;
 711         }
 712
 713       u = nat_user_get_or_create (sm, &ip->src_address, rx_fib_index,
 714                                   thread_index);
 715       if (!u)
 716         {
 717           b->error = node->errors[NAT_IN2OUT_ED_ERROR_CANNOT_CREATE_USER];
 718           nat_elog_warn ("create NAT user failed");
 719           return 0;
 720         }
 721
 722       make_sm_kv (&kv, &ip->src_address, 0, rx_fib_index, 0);
 723
 724       /* Try to find static mapping first */
 725       if (!clib_bihash_search_8_8 (&sm->static_mapping_by_local, &kv, &value))
 726         {
 727           m = pool_elt_at_index (sm->static_mappings, value.value);
 728           new_addr = ip->src_address.as_u32 = m->external_addr.as_u32;
 729           is_sm = 1;
 730           goto create_ses;
 731         }
 732       /* Fallback to 3-tuple key */
 733       else
 734         {
 735           /* Choose same out address as for TCP/UDP session to same destination */
 736           head_index = u->sessions_per_user_list_head_index;
 737           head = pool_elt_at_index (tsm->list_pool, head_index);
 738           elt_index = head->next;
 739           if (PREDICT_FALSE (elt_index == ~0))
 740             ses_index = ~0;
 741           else
 742             {
 743               elt = pool_elt_at_index (tsm->list_pool, elt_index);
 744               ses_index = elt->value;
 745             }
 746
 747           while (ses_index != ~0)
 748             {
 749               s = pool_elt_at_index (tsm->sessions, ses_index);
 750               elt_index = elt->next;
 751               elt = pool_elt_at_index (tsm->list_pool, elt_index);
 752               ses_index = elt->value;
 753
 754               if (s->ext_host_addr.as_u32 == ip->dst_address.as_u32)
 755                 {
 756                   new_addr = ip->src_address.as_u32 = s->out2in.addr.as_u32;
 757
 758                   make_ed_kv (&s_kv, &s->out2in.addr, &ip->dst_address,
 759                               ip->protocol, outside_fib_index, 0, 0);
 760                   if (clib_bihash_search_16_8
 761                       (&tsm->out2in_ed, &s_kv, &s_value))
 762                     goto create_ses;
 763
 764                   break;
 765                 }
 766             }
 767
 768           for (i = 0; i < vec_len (sm->addresses); i++)
 769             {
 770               make_ed_kv (&s_kv, &sm->addresses[i].addr, &ip->dst_address,
 771                           ip->protocol, outside_fib_index, 0, 0);
 772               if (clib_bihash_search_16_8 (&tsm->out2in_ed, &s_kv, &s_value))
 773                 {
 774                   new_addr = ip->src_address.as_u32 =
 775                     sm->addresses[i].addr.as_u32;
 776                   goto create_ses;
 777                 }
 778             }
 779           return 0;
 780         }
 781
 782     create_ses:
 783       s = nat_ed_session_alloc (sm, u, thread_index, now);
 784       if (!s)
 785         {
 786           b->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_USER_SESS_EXCEEDED];
 787           nat44_delete_user_with_no_session (sm, u, thread_index);
 788           nat_elog_warn ("create NAT session failed");
 789           return 0;
 790         }
 791
 792       s->ext_host_addr.as_u32 = ip->dst_address.as_u32;
 793       s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 794       s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 795       s->out2in.addr.as_u32 = new_addr;
 796       s->out2in.fib_index = outside_fib_index;
 797       s->in2out.addr.as_u32 = old_addr;
 798       s->in2out.fib_index = rx_fib_index;
 799       s->in2out.port = s->out2in.port = ip->protocol;
 800       if (is_sm)
 801         s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 802       user_session_increment (sm, u, is_sm);
 803
 804       /* Add to lookup tables */
 805       make_ed_kv (&s_kv, &s->in2out.addr, &ip->dst_address, ip->protocol,
 806                   rx_fib_index, 0, 0);
 807       s_kv.value = s - tsm->sessions;
 808       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &s_kv, 1))
 809         nat_elog_notice ("in2out key add failed");
 810
 811       make_ed_kv (&s_kv, &s->out2in.addr, &ip->dst_address, ip->protocol,
 812                   outside_fib_index, 0, 0);
 813       s_kv.value = s - tsm->sessions;
 814       if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &s_kv, 1))
 815         nat_elog_notice ("out2in key add failed");
 816     }
 817
 818   /* Update IP checksum */
 819   sum = ip->checksum;
 820   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, src_address);
 821   ip->checksum = ip_csum_fold (sum);
 822
 823   /* Accounting */
 824   nat44_session_update_counters (s, now, vlib_buffer_length_in_chain (vm, b),
 825                                  thread_index);
 826   /* Per-user LRU list maintenance */
 827   nat44_session_update_lru (sm, s, thread_index);
 828
 829   /* Hairpinning */
 830   if (vnet_buffer (b)->sw_if_index[VLIB_TX] == ~0)
 831     nat44_ed_hairpinning_unknown_proto (sm, b, ip);
 832
 833   if (vnet_buffer (b)->sw_if_index[VLIB_TX] == ~0)
 834     vnet_buffer (b)->sw_if_index[VLIB_TX] = outside_fib_index;
 835
 836   return s;
 837 }
 838
 839 static inline uword
 840 nat44_ed_in2out_fast_path_node_fn_inline (vlib_main_t * vm,
 841                                           vlib_node_runtime_t * node,
 842                                           vlib_frame_t * frame,
 843                                           int is_output_feature)
 844 {
 845   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
 846   nat_next_t next_index;
 847   snat_main_t *sm = &snat_main;
 848   f64 now = vlib_time_now (vm);
 849   u32 thread_index = vm->thread_index;
 850   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 851   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 852     0, def_slow;
 853
 854   def_slow = is_output_feature ? NAT_NEXT_IN2OUT_ED_OUTPUT_SLOW_PATH :
 855     NAT_NEXT_IN2OUT_ED_SLOW_PATH;
 856
 857   stats_node_index = sm->ed_in2out_node_index;
 858
 859   from = vlib_frame_vector_args (frame);
 860   n_left_from = frame->n_vectors;
 861   next_index = node->cached_next_index;
 862
 863   while (n_left_from > 0)
 864     {
 865       u32 n_left_to_next;
 866
 867       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 868
 869       while (n_left_from > 0 && n_left_to_next > 0)
 870         {
 871           u32 bi0;
 872           vlib_buffer_t *b0;
 873           u32 next0, sw_if_index0, rx_fib_index0, iph_offset0 = 0, proto0,
 874             new_addr0, old_addr0;
 875           u16 old_port0, new_port0;
 876           ip4_header_t *ip0;
 877           udp_header_t *udp0;
 878           tcp_header_t *tcp0;
 879           snat_session_t *s0 = 0;
 880           clib_bihash_kv_16_8_t kv0, value0;
 881           ip_csum_t sum0;
 882
 883           /* speculatively enqueue b0 to the current next frame */
 884           bi0 = from[0];
 885           to_next[0] = bi0;
 886           from += 1;
 887           to_next += 1;
 888           n_left_from -= 1;
 889           n_left_to_next -= 1;
 890
 891           b0 = vlib_get_buffer (vm, bi0);
 892
 893           if (is_output_feature)
 894             {
 895               vnet_feature_next (&nat_buffer_opaque (b0)->arc_next, b0);
 896               iph_offset0 = vnet_buffer (b0)->ip.reass.save_rewrite_length;
 897             }
 898
 899           next0 = nat_buffer_opaque (b0)->arc_next;
 900
 901           ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
 902                                   iph_offset0);
 903
 904           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 905           rx_fib_index0 =
 906             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 907                                                  sw_if_index0);
 908
 909           if (PREDICT_FALSE (ip0->ttl == 1))
 910             {
 911               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 912               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 913                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 914                                            0);
 915               next0 = NAT_NEXT_ICMP_ERROR;
 916               goto trace0;
 917             }
 918
 919           udp0 = ip4_next_header (ip0);
 920           tcp0 = (tcp_header_t *) udp0;
 921           proto0 = ip_proto_to_snat_proto (ip0->protocol);
 922
 923           if (PREDICT_FALSE (proto0 == ~0))
 924             {
 925               next0 = def_slow;
 926               goto trace0;
 927             }
 928
 929           if (is_output_feature)
 930             {
 931               if (PREDICT_FALSE (nat_not_translate_output_feature_fwd
 932                                  (sm, ip0, thread_index, now, vm, b0)))
 933                 goto trace0;
 934             }
 935
 936           if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
 937             {
 938               next0 = def_slow;
 939               goto trace0;
 940             }
 941
 942           make_ed_kv (&kv0, &ip0->src_address, &ip0->dst_address,
 943                       ip0->protocol, rx_fib_index0,
 944                       vnet_buffer (b0)->ip.reass.l4_src_port,
 945                       vnet_buffer (b0)->ip.reass.l4_dst_port);
 946
 947           // lookup for session
 948           if (clib_bihash_search_16_8 (&tsm->in2out_ed, &kv0, &value0))
 949             {
 950               // session does not exist go slow path
 951               next0 = def_slow;
 952               goto trace0;
 953             }
 954           s0 = pool_elt_at_index (tsm->sessions, value0.value);
 955
 956           // drop if session expired
 957           u64 sess_timeout_time;
 958           sess_timeout_time = s0->last_heard +
 959             (f64) nat44_session_get_timeout (sm, s0);
 960           if (now >= sess_timeout_time)
 961             {
 962               // delete session
 963               nat_free_session_data (sm, s0, thread_index, 0);
 964               nat44_delete_session (sm, s0, thread_index);
 965
 966               b0->error = node->errors[NAT_IN2OUT_ED_ERROR_SESS_EXPIRED];
 967               next0 = NAT_NEXT_DROP;
 968               goto trace0;
 969             }
 970           //
 971
 972           b0->flags |= VNET_BUFFER_F_IS_NATED;
 973
 974           if (!is_output_feature)
 975             vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
 976
 977           old_addr0 = ip0->src_address.as_u32;
 978           new_addr0 = ip0->src_address.as_u32 = s0->out2in.addr.as_u32;
 979           sum0 = ip0->checksum;
 980           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 981                                  src_address);
 982           if (PREDICT_FALSE (is_twice_nat_session (s0)))
 983             sum0 = ip_csum_update (sum0, ip0->dst_address.as_u32,
 984                                    s0->ext_host_addr.as_u32, ip4_header_t,
 985                                    dst_address);
 986           ip0->checksum = ip_csum_fold (sum0);
 987
 988           old_port0 = vnet_buffer (b0)->ip.reass.l4_src_port;
 989
 990           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
 991             {
 992               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 993                 {
 994                   new_port0 = udp0->src_port = s0->out2in.port;
 995                   sum0 = tcp0->checksum;
 996                   sum0 =
 997                     ip_csum_update (sum0, old_addr0, new_addr0,
 998                                     ip4_header_t, dst_address);
 999                   sum0 =
1000                     ip_csum_update (sum0, old_port0, new_port0,
1001                                     ip4_header_t, length);
1002                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
1003                     {
1004                       sum0 =
1005                         ip_csum_update (sum0, ip0->dst_address.as_u32,
1006                                         s0->ext_host_addr.as_u32,
1007                                         ip4_header_t, dst_address);
1008                       sum0 =
1009                         ip_csum_update (sum0,
1010                                         vnet_buffer (b0)->ip.
1011                                         reass.l4_dst_port, s0->ext_host_port,
1012                                         ip4_header_t, length);
1013                       tcp0->dst_port = s0->ext_host_port;
1014                       ip0->dst_address.as_u32 = s0->ext_host_addr.as_u32;
1015                     }
1016                   mss_clamping (sm, tcp0, &sum0);
1017                   tcp0->checksum = ip_csum_fold (sum0);
1018                 }
1019               tcp_packets++;
1020               if (nat44_set_tcp_session_state_i2o (sm, s0, b0, thread_index))
1021                 goto trace0;
1022             }
1023           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
1024                    && udp0->checksum)
1025             {
1026               new_port0 = udp0->src_port = s0->out2in.port;
1027               sum0 = udp0->checksum;
1028               sum0 =
1029                 ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1030                                 dst_address);
1031               sum0 =
1032                 ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1033                                 length);
1034               if (PREDICT_FALSE (is_twice_nat_session (s0)))
1035                 {
1036                   sum0 = ip_csum_update (sum0, ip0->dst_address.as_u32,
1037                                          s0->ext_host_addr.as_u32,
1038                                          ip4_header_t, dst_address);
1039                   sum0 =
1040                     ip_csum_update (sum0,
1041                                     vnet_buffer (b0)->ip.reass.l4_dst_port,
1042                                     s0->ext_host_port, ip4_header_t, length);
1043                   udp0->dst_port = s0->ext_host_port;
1044                   ip0->dst_address.as_u32 = s0->ext_host_addr.as_u32;
1045                 }
1046               udp0->checksum = ip_csum_fold (sum0);
1047               udp_packets++;
1048             }
1049           else
1050             {
1051               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1052                 {
1053                   new_port0 = udp0->src_port = s0->out2in.port;
1054                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
1055                     {
1056                       udp0->dst_port = s0->ext_host_port;
1057                       ip0->dst_address.as_u32 = s0->ext_host_addr.as_u32;
1058                     }
1059                   udp_packets++;
1060                 }
1061             }
1062
1063           /* Accounting */
1064           nat44_session_update_counters (s0, now,
1065                                          vlib_buffer_length_in_chain
1066                                          (vm, b0), thread_index);
1067           /* Per-user LRU list maintenance */
1068           nat44_session_update_lru (sm, s0, thread_index);
1069
1070         trace0:
1071           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1072                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1073             {
1074               nat_in2out_ed_trace_t *t =
1075                 vlib_add_trace (vm, node, b0, sizeof (*t));
1076               t->sw_if_index = sw_if_index0;
1077               t->next_index = next0;
1078               t->is_slow_path = 0;
1079
1080               if (s0)
1081                 t->session_index = s0 - tsm->sessions;
1082               else
1083                 t->session_index = ~0;
1084             }
1085
1086           pkts_processed += next0 == nat_buffer_opaque (b0)->arc_next;
1087           /* verify speculative enqueue, maybe switch current next frame */
1088           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1089                                            to_next, n_left_to_next,
1090                                            bi0, next0);
1091         }
1092
1093       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1094     }
1095
1096   vlib_node_increment_counter (vm, stats_node_index,
1097                                NAT_IN2OUT_ED_ERROR_IN2OUT_PACKETS,
1098                                pkts_processed);
1099   vlib_node_increment_counter (vm, stats_node_index,
1100                                NAT_IN2OUT_ED_ERROR_TCP_PACKETS, tcp_packets);
1101   vlib_node_increment_counter (vm, stats_node_index,
1102                                NAT_IN2OUT_ED_ERROR_UDP_PACKETS, udp_packets);
1103   vlib_node_increment_counter (vm, stats_node_index,
1104                                NAT_IN2OUT_ED_ERROR_ICMP_PACKETS,
1105                                icmp_packets);
1106   vlib_node_increment_counter (vm, stats_node_index,
1107                                NAT_IN2OUT_ED_ERROR_OTHER_PACKETS,
1108                                other_packets);
1109   return frame->n_vectors;
1110 }
1111
1112 static inline uword
1113 nat44_ed_in2out_slow_path_node_fn_inline (vlib_main_t * vm,
1114                                           vlib_node_runtime_t * node,
1115                                           vlib_frame_t * frame,
1116                                           int is_output_feature)
1117 {
1118   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
1119   nat_next_t next_index;
1120   snat_main_t *sm = &snat_main;
1121   f64 now = vlib_time_now (vm);
1122   u32 thread_index = vm->thread_index;
1123   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
1124   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets = 0;
1125
1126   stats_node_index = sm->ed_in2out_slowpath_node_index;
1127
1128   from = vlib_frame_vector_args (frame);
1129   n_left_from = frame->n_vectors;
1130   next_index = node->cached_next_index;
1131
1132   while (n_left_from > 0)
1133     {
1134       u32 n_left_to_next;
1135
1136       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1137
1138       while (n_left_from > 0 && n_left_to_next > 0)
1139         {
1140           u32 bi0;
1141           vlib_buffer_t *b0;
1142           u32 next0, sw_if_index0, rx_fib_index0, iph_offset0 = 0, proto0,
1143             new_addr0, old_addr0;
1144           u16 old_port0, new_port0;
1145           ip4_header_t *ip0;
1146           udp_header_t *udp0;
1147           tcp_header_t *tcp0;
1148           icmp46_header_t *icmp0;
1149           snat_session_t *s0 = 0;
1150           clib_bihash_kv_16_8_t kv0, value0;
1151           ip_csum_t sum0;
1152
1153           /* speculatively enqueue b0 to the current next frame */
1154           bi0 = from[0];
1155           to_next[0] = bi0;
1156           from += 1;
1157           to_next += 1;
1158           n_left_from -= 1;
1159           n_left_to_next -= 1;
1160
1161           b0 = vlib_get_buffer (vm, bi0);
1162
1163           if (is_output_feature)
1164             iph_offset0 = vnet_buffer (b0)->ip.reass.save_rewrite_length;
1165
1166           next0 = nat_buffer_opaque (b0)->arc_next;
1167
1168           ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
1169                                   iph_offset0);
1170
1171           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1172           rx_fib_index0 =
1173             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
1174                                                  sw_if_index0);
1175
1176           if (PREDICT_FALSE (ip0->ttl == 1))
1177             {
1178               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1179               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1180                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1181                                            0);
1182               next0 = NAT_NEXT_ICMP_ERROR;
1183               goto trace0;
1184             }
1185
1186           udp0 = ip4_next_header (ip0);
1187           tcp0 = (tcp_header_t *) udp0;
1188           icmp0 = (icmp46_header_t *) udp0;
1189           proto0 = ip_proto_to_snat_proto (ip0->protocol);
1190
1191           if (PREDICT_FALSE (proto0 == ~0))
1192             {
1193               s0 = nat44_ed_in2out_unknown_proto (sm, b0, ip0,
1194                                                   rx_fib_index0,
1195                                                   thread_index, now,
1196                                                   vm, node);
1197               if (!s0)
1198                 next0 = NAT_NEXT_DROP;
1199
1200               other_packets++;
1201               goto trace0;
1202             }
1203
1204           if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1205             {
1206               next0 = icmp_in2out_ed_slow_path
1207                 (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0,
1208                  node, next0, now, thread_index, &s0);
1209               icmp_packets++;
1210               goto trace0;
1211             }
1212
1213           // move down
1214           make_ed_kv (&kv0, &ip0->src_address, &ip0->dst_address,
1215                       ip0->protocol, rx_fib_index0,
1216                       vnet_buffer (b0)->ip.reass.l4_src_port,
1217                       vnet_buffer (b0)->ip.reass.l4_dst_port);
1218
1219           if (clib_bihash_search_16_8 (&tsm->in2out_ed, &kv0, &value0))
1220             {
1221
1222               if (is_output_feature)
1223                 {
1224                   if (PREDICT_FALSE
1225                       (nat44_ed_not_translate_output_feature
1226                        (sm, ip0, ip0->protocol,
1227                         vnet_buffer (b0)->ip.reass.l4_src_port,
1228                         vnet_buffer (b0)->ip.reass.l4_dst_port,
1229                         thread_index, sw_if_index0,
1230                         vnet_buffer (b0)->sw_if_index[VLIB_TX])))
1231                     goto trace0;
1232
1233                   /*
1234                    * Send DHCP packets to the ipv4 stack, or we won't
1235                    * be able to use dhcp client on the outside interface
1236                    */
1237                   if (PREDICT_FALSE
1238                       (proto0 == SNAT_PROTOCOL_UDP
1239                        && (vnet_buffer (b0)->ip.reass.l4_dst_port ==
1240                            clib_host_to_net_u16 (UDP_DST_PORT_dhcp_to_server))
1241                        && ip0->dst_address.as_u32 == 0xffffffff))
1242                     goto trace0;
1243                 }
1244               else
1245                 {
1246                   if (PREDICT_FALSE
1247                       (nat44_ed_not_translate
1248                        (sm, node, sw_if_index0, ip0, proto0, rx_fib_index0,
1249                         thread_index)))
1250                     goto trace0;
1251                 }
1252
1253               next0 = slow_path_ed (sm, b0, rx_fib_index0, &kv0, &s0, node,
1254                                     next0, thread_index, now);
1255
1256               if (PREDICT_FALSE (next0 == NAT_NEXT_DROP))
1257                 goto trace0;
1258
1259               if (PREDICT_FALSE (!s0))
1260                 goto trace0;
1261
1262             }
1263           else
1264             {
1265               s0 = pool_elt_at_index (tsm->sessions, value0.value);
1266             }
1267
1268
1269           b0->flags |= VNET_BUFFER_F_IS_NATED;
1270
1271           if (!is_output_feature)
1272             vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
1273
1274           old_addr0 = ip0->src_address.as_u32;
1275           new_addr0 = ip0->src_address.as_u32 = s0->out2in.addr.as_u32;
1276           sum0 = ip0->checksum;
1277           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1278                                  src_address);
1279           if (PREDICT_FALSE (is_twice_nat_session (s0)))
1280             sum0 = ip_csum_update (sum0, ip0->dst_address.as_u32,
1281                                    s0->ext_host_addr.as_u32, ip4_header_t,
1282                                    dst_address);
1283           ip0->checksum = ip_csum_fold (sum0);
1284
1285           old_port0 = vnet_buffer (b0)->ip.reass.l4_src_port;
1286
1287           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
1288             {
1289               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1290                 {
1291                   new_port0 = udp0->src_port = s0->out2in.port;
1292                   sum0 = tcp0->checksum;
1293                   sum0 =
1294                     ip_csum_update (sum0, old_addr0, new_addr0,
1295                                     ip4_header_t, dst_address);
1296                   sum0 =
1297                     ip_csum_update (sum0, old_port0, new_port0,
1298                                     ip4_header_t, length);
1299                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
1300                     {
1301                       sum0 =
1302                         ip_csum_update (sum0, ip0->dst_address.as_u32,
1303                                         s0->ext_host_addr.as_u32,
1304                                         ip4_header_t, dst_address);
1305                       sum0 =
1306                         ip_csum_update (sum0,
1307                                         vnet_buffer (b0)->ip.
1308                                         reass.l4_dst_port, s0->ext_host_port,
1309                                         ip4_header_t, length);
1310                       tcp0->dst_port = s0->ext_host_port;
1311                       ip0->dst_address.as_u32 = s0->ext_host_addr.as_u32;
1312                     }
1313                   mss_clamping (sm, tcp0, &sum0);
1314                   tcp0->checksum = ip_csum_fold (sum0);
1315                 }
1316               tcp_packets++;
1317               if (nat44_set_tcp_session_state_i2o (sm, s0, b0, thread_index))
1318                 goto trace0;
1319             }
1320           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
1321                    && udp0->checksum)
1322             {
1323               new_port0 = udp0->src_port = s0->out2in.port;
1324               sum0 = udp0->checksum;
1325               sum0 =
1326                 ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1327                                 dst_address);
1328               sum0 =
1329                 ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1330                                 length);
1331               if (PREDICT_FALSE (is_twice_nat_session (s0)))
1332                 {
1333                   sum0 = ip_csum_update (sum0, ip0->dst_address.as_u32,
1334                                          s0->ext_host_addr.as_u32,
1335                                          ip4_header_t, dst_address);
1336                   sum0 =
1337                     ip_csum_update (sum0,
1338                                     vnet_buffer (b0)->ip.reass.l4_dst_port,
1339                                     s0->ext_host_port, ip4_header_t, length);
1340                   udp0->dst_port = s0->ext_host_port;
1341                   ip0->dst_address.as_u32 = s0->ext_host_addr.as_u32;
1342                 }
1343               udp0->checksum = ip_csum_fold (sum0);
1344               udp_packets++;
1345             }
1346           else
1347             {
1348               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1349                 {
1350                   new_port0 = udp0->src_port = s0->out2in.port;
1351                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
1352                     {
1353                       udp0->dst_port = s0->ext_host_port;
1354                       ip0->dst_address.as_u32 = s0->ext_host_addr.as_u32;
1355                     }
1356                   udp_packets++;
1357                 }
1358             }
1359
1360           /* Accounting */
1361           nat44_session_update_counters (s0, now,
1362                                          vlib_buffer_length_in_chain
1363                                          (vm, b0), thread_index);
1364           /* Per-user LRU list maintenance */
1365           nat44_session_update_lru (sm, s0, thread_index);
1366
1367         trace0:
1368           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1369                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1370             {
1371               nat_in2out_ed_trace_t *t =
1372                 vlib_add_trace (vm, node, b0, sizeof (*t));
1373               t->sw_if_index = sw_if_index0;
1374               t->next_index = next0;
1375               t->is_slow_path = 1;
1376
1377               if (s0)
1378                 t->session_index = s0 - tsm->sessions;
1379               else
1380                 t->session_index = ~0;
1381             }
1382
1383           pkts_processed += next0 == nat_buffer_opaque (b0)->arc_next;
1384
1385           /* verify speculative enqueue, maybe switch current next frame */
1386           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1387                                            to_next, n_left_to_next,
1388                                            bi0, next0);
1389         }
1390
1391       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1392     }
1393
1394   vlib_node_increment_counter (vm, stats_node_index,
1395                                NAT_IN2OUT_ED_ERROR_IN2OUT_PACKETS,
1396                                pkts_processed);
1397   vlib_node_increment_counter (vm, stats_node_index,
1398                                NAT_IN2OUT_ED_ERROR_TCP_PACKETS, tcp_packets);
1399   vlib_node_increment_counter (vm, stats_node_index,
1400                                NAT_IN2OUT_ED_ERROR_UDP_PACKETS, udp_packets);
1401   vlib_node_increment_counter (vm, stats_node_index,
1402                                NAT_IN2OUT_ED_ERROR_ICMP_PACKETS,
1403                                icmp_packets);
1404   vlib_node_increment_counter (vm, stats_node_index,
1405                                NAT_IN2OUT_ED_ERROR_OTHER_PACKETS,
1406                                other_packets);
1407   return frame->n_vectors;
1408 }
1409
1410 VLIB_NODE_FN (nat44_ed_in2out_node) (vlib_main_t * vm,
1411                                      vlib_node_runtime_t * node,
1412                                      vlib_frame_t * frame)
1413 {
1414   return nat44_ed_in2out_fast_path_node_fn_inline (vm, node, frame, 0);
1415 }
1416
1417 /* *INDENT-OFF* */
1418 VLIB_REGISTER_NODE (nat44_ed_in2out_node) = {
1419   .name = "nat44-ed-in2out",
1420   .vector_size = sizeof (u32),
1421   .sibling_of = "nat-default",
1422   .format_trace = format_nat_in2out_ed_trace,
1423   .type = VLIB_NODE_TYPE_INTERNAL,
1424   .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
1425   .error_strings = nat_in2out_ed_error_strings,
1426   .runtime_data_bytes = sizeof (snat_runtime_t),
1427 };
1428 /* *INDENT-ON* */
1429
1430 VLIB_NODE_FN (nat44_ed_in2out_output_node) (vlib_main_t * vm,
1431                                             vlib_node_runtime_t * node,
1432                                             vlib_frame_t * frame)
1433 {
1434   return nat44_ed_in2out_fast_path_node_fn_inline (vm, node, frame, 1);
1435 }
1436
1437 /* *INDENT-OFF* */
1438 VLIB_REGISTER_NODE (nat44_ed_in2out_output_node) = {
1439   .name = "nat44-ed-in2out-output",
1440   .vector_size = sizeof (u32),
1441   .sibling_of = "nat-default",
1442   .format_trace = format_nat_in2out_ed_trace,
1443   .type = VLIB_NODE_TYPE_INTERNAL,
1444   .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
1445   .error_strings = nat_in2out_ed_error_strings,
1446   .runtime_data_bytes = sizeof (snat_runtime_t),
1447 };
1448 /* *INDENT-ON* */
1449
1450 VLIB_NODE_FN (nat44_ed_in2out_slowpath_node) (vlib_main_t * vm,
1451                                               vlib_node_runtime_t *
1452                                               node, vlib_frame_t * frame)
1453 {
1454   return nat44_ed_in2out_slow_path_node_fn_inline (vm, node, frame, 0);
1455 }
1456
1457 /* *INDENT-OFF* */
1458 VLIB_REGISTER_NODE (nat44_ed_in2out_slowpath_node) = {
1459   .name = "nat44-ed-in2out-slowpath",
1460   .vector_size = sizeof (u32),
1461   .sibling_of = "nat-default",
1462   .format_trace = format_nat_in2out_ed_trace,
1463   .type = VLIB_NODE_TYPE_INTERNAL,
1464   .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
1465   .error_strings = nat_in2out_ed_error_strings,
1466   .runtime_data_bytes = sizeof (snat_runtime_t),
1467 };
1468 /* *INDENT-ON* */
1469
1470 VLIB_NODE_FN (nat44_ed_in2out_output_slowpath_node) (vlib_main_t * vm,
1471                                                      vlib_node_runtime_t
1472                                                      * node,
1473                                                      vlib_frame_t * frame)
1474 {
1475   return nat44_ed_in2out_slow_path_node_fn_inline (vm, node, frame, 1);
1476 }
1477
1478 /* *INDENT-OFF* */
1479 VLIB_REGISTER_NODE (nat44_ed_in2out_output_slowpath_node) = {
1480   .name = "nat44-ed-in2out-output-slowpath",
1481   .vector_size = sizeof (u32),
1482   .sibling_of = "nat-default",
1483   .format_trace = format_nat_in2out_ed_trace,
1484   .type = VLIB_NODE_TYPE_INTERNAL,
1485   .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
1486   .error_strings = nat_in2out_ed_error_strings,
1487   .runtime_data_bytes = sizeof (snat_runtime_t),
1488 };
1489 /* *INDENT-ON* */
1490
1491 static u8 *
1492 format_nat_pre_trace (u8 * s, va_list * args)
1493 {
1494   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1495   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1496   nat_pre_trace_t *t = va_arg (*args, nat_pre_trace_t *);
1497   return format (s, "in2out next_index %d", t->next_index);
1498 }
1499
1500 VLIB_NODE_FN (nat_pre_in2out_node)
1501   (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
1502 {
1503   return nat_pre_node_fn_inline (vm, node, frame,
1504                                  NAT_NEXT_IN2OUT_ED_FAST_PATH);
1505 }
1506
1507 /* *INDENT-OFF* */
1508 VLIB_REGISTER_NODE (nat_pre_in2out_node) = {
1509   .name = "nat-pre-in2out",
1510   .vector_size = sizeof (u32),
1511   .sibling_of = "nat-default",
1512   .format_trace = format_nat_pre_trace,
1513   .type = VLIB_NODE_TYPE_INTERNAL,
1514   .n_errors = 0,
1515 };
1516 /* *INDENT-ON* */
1517
1518 /*
1519  * fd.io coding-style-patch-verification: ON
1520  *
1521  * Local Variables:
1522  * eval: (c-set-style "gnu")
1523  * End:
1524  */