src/plugins/nat/nat44-ed/nat44_ed_in2out.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/ip/ip.h>
  23 #include <vnet/ethernet/ethernet.h>
  24 #include <vnet/fib/ip4_fib.h>
  25 #include <vnet/udp/udp_local.h>
  26 #include <vppinfra/error.h>
  27
  28 #include <nat/lib/nat_syslog.h>
  29 #include <nat/lib/nat_inlines.h>
  30 #include <nat/lib/ipfix_logging.h>
  31
  32 #include <nat/nat44-ed/nat44_ed.h>
  33 #include <nat/nat44-ed/nat44_ed_inlines.h>
  34
  35 /* number of attempts to get a port for ED overloading algorithm, if rolling
  36  * a dice this many times doesn't produce a free port, it's treated
  37  * as if there were no free ports available to conserve resources */
  38 #define ED_PORT_ALLOC_ATTEMPTS (10)
  39
  40 static char *nat_in2out_ed_error_strings[] = {
  41 #define _(sym,string) string,
  42   foreach_nat_in2out_ed_error
  43 #undef _
  44 };
  45
  46 typedef struct
  47 {
  48   u32 sw_if_index;
  49   u32 next_index;
  50   u32 session_index;
  51   nat_translation_error_e translation_error;
  52   nat_6t_flow_t i2of;
  53   nat_6t_flow_t o2if;
  54   clib_bihash_kv_16_8_t search_key;
  55   u8 is_slow_path;
  56   u8 translation_via_i2of;
  57   u8 lookup_skipped;
  58 } nat_in2out_ed_trace_t;
  59
  60 static u8 *
  61 format_nat_in2out_ed_trace (u8 * s, va_list * args)
  62 {
  63   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  64   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  65   nat_in2out_ed_trace_t *t = va_arg (*args, nat_in2out_ed_trace_t *);
  66   char *tag;
  67
  68   tag =
  69     t->is_slow_path ? "NAT44_IN2OUT_ED_SLOW_PATH" :
  70     "NAT44_IN2OUT_ED_FAST_PATH";
  71
  72   s = format (s, "%s: sw_if_index %d, next index %d, session %d", tag,
  73               t->sw_if_index, t->next_index, t->session_index);
  74   if (~0 != t->session_index)
  75     {
  76       s = format (s, ", translation result '%U' via %s",
  77                   format_nat_ed_translation_error, t->translation_error,
  78                   t->translation_via_i2of ? "i2of" : "o2if");
  79       s = format (s, "\n  i2of %U", format_nat_6t_flow, &t->i2of);
  80       s = format (s, "\n  o2if %U", format_nat_6t_flow, &t->o2if);
  81     }
  82   if (!t->is_slow_path)
  83     {
  84       if (t->lookup_skipped)
  85         {
  86           s = format (s, "\n lookup skipped - cached session index used");
  87         }
  88       else
  89         {
  90           s = format (s, "\n  search key %U", format_ed_session_kvp,
  91                       &t->search_key);
  92         }
  93     }
  94
  95   return s;
  96 }
  97
  98 /**
  99  * @brief Check if packet should be translated
 100  *
 101  * Packets aimed at outside interface and external address with active session
 102  * should be translated.
 103  *
 104  * @param sm            NAT main
 105  * @param rt            NAT runtime data
 106  * @param sw_if_index0  index of the inside interface
 107  * @param ip0           IPv4 header
 108  * @param proto0        NAT protocol
 109  * @param rx_fib_index0 RX FIB index
 110  *
 111  * @returns 0 if packet should be translated otherwise 1
 112  */
 113 static inline int
 114 snat_not_translate_fast (snat_main_t *sm, vlib_node_runtime_t *node,
 115                          u32 sw_if_index0, ip4_header_t *ip0, u32 proto0,
 116                          u32 rx_fib_index0)
 117 {
 118   fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
 119   nat_outside_fib_t *outside_fib;
 120   fib_prefix_t pfx = {
 121     .fp_proto = FIB_PROTOCOL_IP4,
 122     .fp_len = 32,
 123     .fp_addr = {
 124                 .ip4.as_u32 = ip0->dst_address.as_u32,
 125                 }
 126     ,
 127   };
 128
 129   /* Don't NAT packet aimed at the intfc address */
 130   if (PREDICT_FALSE (
 131         is_interface_addr (sm, node, sw_if_index0, ip0->dst_address.as_u32)))
 132     return 1;
 133
 134   fei = fib_table_lookup (rx_fib_index0, &pfx);
 135   if (FIB_NODE_INDEX_INVALID != fei)
 136     {
 137       u32 sw_if_index = fib_entry_get_resolving_interface (fei);
 138       if (sw_if_index == ~0)
 139         {
 140           vec_foreach (outside_fib, sm->outside_fibs)
 141             {
 142               fei = fib_table_lookup (outside_fib->fib_index, &pfx);
 143               if (FIB_NODE_INDEX_INVALID != fei)
 144                 {
 145                   sw_if_index = fib_entry_get_resolving_interface (fei);
 146                   if (sw_if_index != ~0)
 147                     break;
 148                 }
 149             }
 150         }
 151       if (sw_if_index == ~0)
 152         return 1;
 153
 154       snat_interface_t *i;
 155       pool_foreach (i, sm->interfaces)
 156         {
 157           /* NAT packet aimed at outside interface */
 158           if ((nat_interface_is_outside (i)) &&
 159               (sw_if_index == i->sw_if_index))
 160             return 0;
 161         }
 162     }
 163
 164   return 1;
 165 }
 166
 167 static int
 168 nat_ed_alloc_addr_and_port_with_snat_address (
 169   snat_main_t *sm, u32 nat_proto, u32 thread_index, snat_address_t *a,
 170   u16 port_per_thread, u32 snat_thread_index, snat_session_t *s,
 171   ip4_address_t *outside_addr, u16 *outside_port)
 172 {
 173   const u16 port_thread_offset = (port_per_thread * snat_thread_index) + 1024;
 174
 175   s->o2i.match.daddr = a->addr;
 176   /* first try port suggested by caller */
 177   u16 port = clib_net_to_host_u16 (*outside_port);
 178   u16 port_offset = port - port_thread_offset;
 179   if (port <= port_thread_offset ||
 180       port > port_thread_offset + port_per_thread)
 181     {
 182       /* need to pick a different port, suggested port doesn't fit in
 183        * this thread's port range */
 184       port_offset = snat_random_port (0, port_per_thread - 1);
 185       port = port_thread_offset + port_offset;
 186     }
 187   u16 attempts = ED_PORT_ALLOC_ATTEMPTS;
 188   do
 189     {
 190       if (NAT_PROTOCOL_ICMP == nat_proto)
 191         {
 192           s->o2i.match.sport = clib_host_to_net_u16 (port);
 193         }
 194       s->o2i.match.dport = clib_host_to_net_u16 (port);
 195       if (0 == nat_ed_ses_o2i_flow_hash_add_del (sm, thread_index, s, 2))
 196         {
 197 #define _(N, i, n, s)                                                         \
 198   case NAT_PROTOCOL_##N:                                                      \
 199     ++a->busy_##n##_port_refcounts[port];                                     \
 200     a->busy_##n##_ports_per_thread[thread_index]++;                           \
 201     a->busy_##n##_ports++;                                                    \
 202     break;
 203           switch (nat_proto)
 204             {
 205               foreach_nat_protocol;
 206             default:
 207               nat_elog_info (sm, "unknown protocol");
 208               return 1;
 209             }
 210 #undef _
 211           *outside_addr = a->addr;
 212           *outside_port = clib_host_to_net_u16 (port);
 213           return 0;
 214         }
 215       port_offset = snat_random_port (0, port_per_thread - 1);
 216       port = port_thread_offset + port_offset;
 217       --attempts;
 218     }
 219   while (attempts > 0);
 220   return 1;
 221 }
 222
 223 static int
 224 nat_ed_alloc_addr_and_port (snat_main_t *sm, u32 rx_fib_index, u32 nat_proto,
 225                             u32 thread_index, ip4_address_t s_addr,
 226                             u16 port_per_thread, u32 snat_thread_index,
 227                             snat_session_t *s, ip4_address_t *outside_addr,
 228                             u16 *outside_port)
 229 {
 230   int i;
 231   snat_address_t *a, *ga = 0;
 232
 233   if (vec_len (sm->addresses) > 0)
 234     {
 235       int s_addr_offset = s_addr.as_u32 % vec_len (sm->addresses);
 236
 237       for (i = s_addr_offset; i < vec_len (sm->addresses); ++i)
 238         {
 239           a = sm->addresses + i;
 240           if (a->fib_index == rx_fib_index)
 241             {
 242               return nat_ed_alloc_addr_and_port_with_snat_address (
 243                 sm, nat_proto, thread_index, a, port_per_thread,
 244                 snat_thread_index, s, outside_addr, outside_port);
 245             }
 246           else if (a->fib_index == ~0)
 247             {
 248               ga = a;
 249             }
 250         }
 251
 252       for (i = 0; i < s_addr_offset; ++i)
 253         {
 254           a = sm->addresses + i;
 255           if (a->fib_index == rx_fib_index)
 256             {
 257               return nat_ed_alloc_addr_and_port_with_snat_address (
 258                 sm, nat_proto, thread_index, a, port_per_thread,
 259                 snat_thread_index, s, outside_addr, outside_port);
 260             }
 261           else if (a->fib_index == ~0)
 262             {
 263               ga = a;
 264             }
 265         }
 266
 267       if (ga)
 268         {
 269           return nat_ed_alloc_addr_and_port_with_snat_address (
 270             sm, nat_proto, thread_index, a, port_per_thread, snat_thread_index,
 271             s, outside_addr, outside_port);
 272         }
 273     }
 274   /* Totally out of translations to use... */
 275   nat_ipfix_logging_addresses_exhausted (thread_index, 0);
 276   return 1;
 277 }
 278
 279 static_always_inline u32
 280 nat_outside_fib_index_lookup (snat_main_t * sm, ip4_address_t addr)
 281 {
 282   fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
 283   nat_outside_fib_t *outside_fib;
 284   fib_prefix_t pfx = {
 285     .fp_proto = FIB_PROTOCOL_IP4,
 286     .fp_len = 32,
 287     .fp_addr = {.ip4.as_u32 = addr.as_u32,}
 288     ,
 289   };
 290   // TODO: multiple vrfs none can resolve addr
 291   vec_foreach (outside_fib, sm->outside_fibs)
 292     {
 293       fei = fib_table_lookup (outside_fib->fib_index, &pfx);
 294       if (FIB_NODE_INDEX_INVALID != fei)
 295         {
 296           if (fib_entry_get_resolving_interface (fei) != ~0)
 297             {
 298               return outside_fib->fib_index;
 299             }
 300         }
 301     }
 302   return ~0;
 303 }
 304
 305 static_always_inline int
 306 nat44_ed_external_sm_lookup (snat_main_t *sm, ip4_address_t match_addr,
 307                              u16 match_port, nat_protocol_t match_protocol,
 308                              u32 match_fib_index, ip4_address_t *daddr,
 309                              u16 *dport)
 310 {
 311   clib_bihash_kv_8_8_t kv, value;
 312   init_nat_k (&kv, match_addr, match_port, match_fib_index, match_protocol);
 313   if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
 314     {
 315       /* Try address only mapping */
 316       init_nat_k (&kv, match_addr, 0, 0, 0);
 317       if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv,
 318                                   &value))
 319         return 0;
 320     }
 321
 322   snat_static_mapping_t *m =
 323     pool_elt_at_index (sm->static_mappings, value.value);
 324   *daddr = m->local_addr;
 325   if (dport)
 326     {
 327       /* Address only mapping doesn't change port */
 328       *dport = is_addr_only_static_mapping (m) ? match_port : m->local_port;
 329     }
 330   return 1;
 331 }
 332
 333 static u32
 334 slow_path_ed (vlib_main_t *vm, snat_main_t *sm, vlib_buffer_t *b,
 335               ip4_address_t l_addr, ip4_address_t r_addr, u16 l_port,
 336               u16 r_port, u8 proto, u32 rx_fib_index,
 337               snat_session_t **sessionp, vlib_node_runtime_t *node, u32 next,
 338               u32 thread_index, f64 now)
 339 {
 340   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 341   ip4_address_t outside_addr;
 342   u16 outside_port;
 343   u32 outside_fib_index;
 344   u8 is_identity_nat;
 345
 346   u32 nat_proto = ip_proto_to_nat_proto (proto);
 347   snat_session_t *s = NULL;
 348   lb_nat_type_t lb = 0;
 349   ip4_address_t daddr = r_addr;
 350   u16 dport = r_port;
 351
 352   if (PREDICT_TRUE (nat_proto == NAT_PROTOCOL_TCP))
 353     {
 354       if (PREDICT_FALSE
 355           (!tcp_flags_is_init
 356            (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags)))
 357         {
 358           b->error = node->errors[NAT_IN2OUT_ED_ERROR_NON_SYN];
 359           return NAT_NEXT_DROP;
 360         }
 361     }
 362
 363   if (PREDICT_FALSE
 364       (nat44_ed_maximum_sessions_exceeded (sm, rx_fib_index, thread_index)))
 365     {
 366       if (!nat_lru_free_one (sm, thread_index, now))
 367         {
 368           b->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 369           nat_ipfix_logging_max_sessions (thread_index,
 370                                           sm->max_translations_per_thread);
 371           nat_elog_notice (sm, "maximum sessions exceeded");
 372           return NAT_NEXT_DROP;
 373         }
 374     }
 375
 376   outside_fib_index = sm->outside_fib_index;
 377
 378   switch (vec_len (sm->outside_fibs))
 379     {
 380     case 0:
 381       outside_fib_index = sm->outside_fib_index;
 382       break;
 383     case 1:
 384       outside_fib_index = sm->outside_fibs[0].fib_index;
 385       break;
 386     default:
 387       outside_fib_index = nat_outside_fib_index_lookup (sm, r_addr);
 388       break;
 389     }
 390
 391   ip4_address_t sm_addr;
 392   u16 sm_port;
 393   u32 sm_fib_index;
 394   /* First try to match static mapping by local address and port */
 395   int is_sm;
 396   if (snat_static_mapping_match (vm, sm, l_addr, l_port, rx_fib_index,
 397                                  nat_proto, &sm_addr, &sm_port, &sm_fib_index,
 398                                  0, 0, 0, &lb, 0, &is_identity_nat, 0))
 399     {
 400       is_sm = 0;
 401     }
 402   else
 403     {
 404       is_sm = 1;
 405     }
 406
 407   if (PREDICT_FALSE (is_sm && is_identity_nat))
 408     {
 409       *sessionp = NULL;
 410       return next;
 411     }
 412
 413   s = nat_ed_session_alloc (sm, thread_index, now, proto);
 414   ASSERT (s);
 415
 416   if (!is_sm)
 417     {
 418       s->in2out.addr = l_addr;
 419       s->in2out.port = l_port;
 420       s->nat_proto = nat_proto;
 421       s->in2out.fib_index = rx_fib_index;
 422       s->out2in.fib_index = outside_fib_index;
 423
 424       // suggest using local port to allocation function
 425       outside_port = l_port;
 426
 427       // hairpinning?
 428       int is_hairpinning = nat44_ed_external_sm_lookup (
 429         sm, r_addr, r_port, nat_proto, outside_fib_index, &daddr, &dport);
 430       s->flags |= is_hairpinning * SNAT_SESSION_FLAG_HAIRPINNING;
 431
 432       // destination addr/port updated with real values in
 433       // nat_ed_alloc_addr_and_port
 434       nat_6t_o2i_flow_init (sm, thread_index, s, daddr, dport, daddr, 0,
 435                             s->out2in.fib_index, proto);
 436       nat_6t_flow_daddr_rewrite_set (&s->o2i, l_addr.as_u32);
 437       if (NAT_PROTOCOL_ICMP == nat_proto)
 438         {
 439           nat_6t_flow_icmp_id_rewrite_set (&s->o2i, l_port);
 440         }
 441       else
 442         {
 443           nat_6t_flow_dport_rewrite_set (&s->o2i, l_port);
 444         }
 445       nat_6t_flow_txfib_rewrite_set (&s->o2i, rx_fib_index);
 446
 447       if (nat_ed_alloc_addr_and_port (
 448             sm, rx_fib_index, nat_proto, thread_index, l_addr,
 449             sm->port_per_thread, tsm->snat_thread_index, s, &outside_addr,
 450             &outside_port))
 451         {
 452           nat_elog_notice (sm, "addresses exhausted");
 453           b->error = node->errors[NAT_IN2OUT_ED_ERROR_OUT_OF_PORTS];
 454           nat_ed_session_delete (sm, s, thread_index, 1);
 455           return NAT_NEXT_DROP;
 456         }
 457       s->out2in.addr = outside_addr;
 458       s->out2in.port = outside_port;
 459     }
 460   else
 461     {
 462       // static mapping
 463       s->out2in.addr = outside_addr = sm_addr;
 464       s->out2in.port = outside_port = sm_port;
 465       s->in2out.addr = l_addr;
 466       s->in2out.port = l_port;
 467       s->nat_proto = nat_proto;
 468       s->in2out.fib_index = rx_fib_index;
 469       s->out2in.fib_index = outside_fib_index;
 470       s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 471
 472       // hairpinning?
 473       int is_hairpinning = nat44_ed_external_sm_lookup (
 474         sm, r_addr, r_port, nat_proto, outside_fib_index, &daddr, &dport);
 475       s->flags |= is_hairpinning * SNAT_SESSION_FLAG_HAIRPINNING;
 476
 477       if (NAT_PROTOCOL_ICMP == nat_proto)
 478         {
 479           nat_6t_o2i_flow_init (sm, thread_index, s, daddr, sm_port, sm_addr,
 480                                 sm_port, s->out2in.fib_index, proto);
 481           nat_6t_flow_icmp_id_rewrite_set (&s->o2i, l_port);
 482         }
 483       else
 484         {
 485           nat_6t_o2i_flow_init (sm, thread_index, s, daddr, dport, sm_addr,
 486                                 sm_port, s->out2in.fib_index, proto);
 487           nat_6t_flow_dport_rewrite_set (&s->o2i, l_port);
 488         }
 489       nat_6t_flow_daddr_rewrite_set (&s->o2i, l_addr.as_u32);
 490       nat_6t_flow_txfib_rewrite_set (&s->o2i, rx_fib_index);
 491       if (nat_ed_ses_o2i_flow_hash_add_del (sm, thread_index, s, 2))
 492         {
 493           nat_elog_notice (sm, "out2in key add failed");
 494           goto error;
 495         }
 496     }
 497
 498   if (lb)
 499     s->flags |= SNAT_SESSION_FLAG_LOAD_BALANCING;
 500   s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 501   s->ext_host_addr = r_addr;
 502   s->ext_host_port = r_port;
 503
 504   nat_6t_i2o_flow_init (sm, thread_index, s, l_addr, l_port, r_addr, r_port,
 505                         rx_fib_index, proto);
 506   nat_6t_flow_saddr_rewrite_set (&s->i2o, outside_addr.as_u32);
 507   nat_6t_flow_daddr_rewrite_set (&s->i2o, daddr.as_u32);
 508   if (NAT_PROTOCOL_ICMP == nat_proto)
 509     {
 510       nat_6t_flow_icmp_id_rewrite_set (&s->i2o, outside_port);
 511     }
 512   else
 513     {
 514       nat_6t_flow_sport_rewrite_set (&s->i2o, outside_port);
 515       nat_6t_flow_dport_rewrite_set (&s->i2o, dport);
 516     }
 517   nat_6t_flow_txfib_rewrite_set (&s->i2o, outside_fib_index);
 518
 519   if (nat_ed_ses_i2o_flow_hash_add_del (sm, thread_index, s, 1))
 520     {
 521       nat_elog_notice (sm, "in2out key add failed");
 522       goto error;
 523     }
 524
 525   /* log NAT event */
 526   nat_ipfix_logging_nat44_ses_create (thread_index,
 527                                       s->in2out.addr.as_u32,
 528                                       s->out2in.addr.as_u32,
 529                                       s->nat_proto,
 530                                       s->in2out.port,
 531                                       s->out2in.port, s->in2out.fib_index);
 532
 533   nat_syslog_nat44_sadd (0, s->in2out.fib_index, &s->in2out.addr,
 534                          s->in2out.port, &s->ext_host_nat_addr,
 535                          s->ext_host_nat_port, &s->out2in.addr, s->out2in.port,
 536                          &s->ext_host_addr, s->ext_host_port, s->nat_proto, 0);
 537
 538   per_vrf_sessions_register_session (s, thread_index);
 539
 540   *sessionp = s;
 541   return next;
 542 error:
 543   if (s)
 544     {
 545       if (!is_sm)
 546         {
 547           snat_free_outside_address_and_port (sm->addresses, thread_index,
 548                                               &outside_addr, outside_port,
 549                                               nat_proto);
 550         }
 551       nat_ed_session_delete (sm, s, thread_index, 1);
 552     }
 553   *sessionp = s = NULL;
 554   return NAT_NEXT_DROP;
 555 }
 556
 557 static_always_inline int
 558 nat44_ed_not_translate (vlib_main_t *vm, snat_main_t *sm,
 559                         vlib_node_runtime_t *node, u32 sw_if_index,
 560                         vlib_buffer_t *b, ip4_header_t *ip, u32 proto,
 561                         u32 rx_fib_index, u32 thread_index)
 562 {
 563   clib_bihash_kv_16_8_t kv, value;
 564
 565   init_ed_k (&kv, ip->dst_address, vnet_buffer (b)->ip.reass.l4_dst_port,
 566              ip->src_address, vnet_buffer (b)->ip.reass.l4_src_port,
 567              sm->outside_fib_index, ip->protocol);
 568
 569   /* NAT packet aimed at external address if has active sessions */
 570   if (clib_bihash_search_16_8 (&sm->flow_hash, &kv, &value))
 571     {
 572       /* or is static mappings */
 573       ip4_address_t placeholder_addr;
 574       u16 placeholder_port;
 575       u32 placeholder_fib_index;
 576       if (!snat_static_mapping_match (
 577             vm, sm, ip->dst_address, vnet_buffer (b)->ip.reass.l4_dst_port,
 578             sm->outside_fib_index, proto, &placeholder_addr, &placeholder_port,
 579             &placeholder_fib_index, 1, 0, 0, 0, 0, 0, 0))
 580         return 0;
 581     }
 582   else
 583     return 0;
 584
 585   if (sm->forwarding_enabled)
 586     return 1;
 587
 588   return snat_not_translate_fast (sm, node, sw_if_index, ip, proto,
 589                                   rx_fib_index);
 590 }
 591
 592 static_always_inline int
 593 nat_not_translate_output_feature_fwd (snat_main_t * sm, ip4_header_t * ip,
 594                                       u32 thread_index, f64 now,
 595                                       vlib_main_t * vm, vlib_buffer_t * b)
 596 {
 597   clib_bihash_kv_16_8_t kv, value;
 598   snat_session_t *s = 0;
 599   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 600
 601   if (!sm->forwarding_enabled)
 602     return 0;
 603
 604   if (ip->protocol == IP_PROTOCOL_ICMP)
 605     {
 606       ip4_address_t lookup_saddr, lookup_daddr;
 607       u16 lookup_sport, lookup_dport;
 608       u8 lookup_protocol;
 609       if (nat_get_icmp_session_lookup_values (b, ip, &lookup_saddr,
 610                                               &lookup_sport, &lookup_daddr,
 611                                               &lookup_dport, &lookup_protocol))
 612         return 0;
 613       init_ed_k (&kv, lookup_saddr, lookup_sport, lookup_daddr, lookup_dport,
 614                  0, lookup_protocol);
 615     }
 616   else if (ip->protocol == IP_PROTOCOL_UDP || ip->protocol == IP_PROTOCOL_TCP)
 617     {
 618       init_ed_k (&kv, ip->src_address, vnet_buffer (b)->ip.reass.l4_src_port,
 619                  ip->dst_address, vnet_buffer (b)->ip.reass.l4_dst_port, 0,
 620                  ip->protocol);
 621     }
 622   else
 623     {
 624       init_ed_k (&kv, ip->src_address, 0, ip->dst_address, 0, 0,
 625                  ip->protocol);
 626     }
 627
 628   if (!clib_bihash_search_16_8 (&sm->flow_hash, &kv, &value))
 629     {
 630       ASSERT (thread_index == ed_value_get_thread_index (&value));
 631       s =
 632         pool_elt_at_index (tsm->sessions,
 633                            ed_value_get_session_index (&value));
 634
 635       if (is_fwd_bypass_session (s))
 636         {
 637           if (ip->protocol == IP_PROTOCOL_TCP)
 638             {
 639               nat44_set_tcp_session_state_i2o (sm, now, s, b, thread_index);
 640             }
 641           /* Accounting */
 642           nat44_session_update_counters (s, now,
 643                                          vlib_buffer_length_in_chain (vm, b),
 644                                          thread_index);
 645           /* Per-user LRU list maintenance */
 646           nat44_session_update_lru (sm, s, thread_index);
 647           return 1;
 648         }
 649       else
 650         return 0;
 651     }
 652
 653   return 0;
 654 }
 655
 656 static_always_inline int
 657 nat44_ed_not_translate_output_feature (snat_main_t * sm, ip4_header_t * ip,
 658                                        u16 src_port, u16 dst_port,
 659                                        u32 thread_index, u32 rx_sw_if_index,
 660                                        u32 tx_sw_if_index, f64 now)
 661 {
 662   clib_bihash_kv_16_8_t kv, value;
 663   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 664   snat_interface_t *i;
 665   snat_session_t *s;
 666   u32 rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (rx_sw_if_index);
 667   u32 tx_fib_index = ip4_fib_table_get_index_for_sw_if_index (tx_sw_if_index);
 668
 669   /* src NAT check */
 670   init_ed_k (&kv, ip->src_address, src_port, ip->dst_address, dst_port,
 671              tx_fib_index, ip->protocol);
 672   if (!clib_bihash_search_16_8 (&sm->flow_hash, &kv, &value))
 673     {
 674       ASSERT (thread_index == ed_value_get_thread_index (&value));
 675       s =
 676         pool_elt_at_index (tsm->sessions,
 677                            ed_value_get_session_index (&value));
 678       if (nat44_is_ses_closed (s)
 679           && (!s->tcp_closed_timestamp || now >= s->tcp_closed_timestamp))
 680         {
 681           nat_free_session_data (sm, s, thread_index, 0);
 682           nat_ed_session_delete (sm, s, thread_index, 1);
 683         }
 684       return 1;
 685     }
 686
 687   /* dst NAT check */
 688   init_ed_k (&kv, ip->dst_address, dst_port, ip->src_address, src_port,
 689              rx_fib_index, ip->protocol);
 690   if (!clib_bihash_search_16_8 (&sm->flow_hash, &kv, &value))
 691     {
 692       ASSERT (thread_index == ed_value_get_thread_index (&value));
 693       s =
 694         pool_elt_at_index (tsm->sessions,
 695                            ed_value_get_session_index (&value));
 696
 697       if (is_fwd_bypass_session (s))
 698         return 0;
 699
 700       /* hairpinning */
 701       pool_foreach (i, sm->output_feature_interfaces)
 702        {
 703         if ((nat_interface_is_inside (i)) && (rx_sw_if_index == i->sw_if_index))
 704            return 0;
 705       }
 706       return 1;
 707     }
 708
 709   return 0;
 710 }
 711
 712 static inline u32
 713 icmp_in2out_ed_slow_path (snat_main_t *sm, vlib_buffer_t *b, ip4_header_t *ip,
 714                           icmp46_header_t *icmp, u32 sw_if_index,
 715                           u32 rx_fib_index, vlib_node_runtime_t *node,
 716                           u32 next, f64 now, u32 thread_index,
 717                           nat_protocol_t nat_proto, snat_session_t **s_p)
 718 {
 719   vlib_main_t *vm = vlib_get_main ();
 720   u16 checksum;
 721   int err;
 722   snat_session_t *s = NULL;
 723   u8 lookup_protocol = ip->protocol;
 724   u16 lookup_sport, lookup_dport;
 725   ip4_address_t lookup_saddr, lookup_daddr;
 726
 727   err = nat_get_icmp_session_lookup_values (b, ip, &lookup_saddr,
 728                                             &lookup_sport, &lookup_daddr,
 729                                             &lookup_dport, &lookup_protocol);
 730   if (err != 0)
 731     {
 732       b->error = node->errors[err];
 733       return NAT_NEXT_DROP;
 734     }
 735
 736   if (vnet_buffer (b)->sw_if_index[VLIB_TX] != ~0)
 737     {
 738       if (PREDICT_FALSE (nat44_ed_not_translate_output_feature (
 739             sm, ip, lookup_sport, lookup_dport, thread_index, sw_if_index,
 740             vnet_buffer (b)->sw_if_index[VLIB_TX], now)))
 741         {
 742           return next;
 743         }
 744     }
 745   else
 746     {
 747       if (PREDICT_FALSE (nat44_ed_not_translate (vm, sm, node, sw_if_index, b,
 748                                                  ip, NAT_PROTOCOL_ICMP,
 749                                                  rx_fib_index, thread_index)))
 750         {
 751           return next;
 752         }
 753     }
 754
 755   if (PREDICT_FALSE (icmp_type_is_error_message (
 756         vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags)))
 757     {
 758       b->error = node->errors[NAT_IN2OUT_ED_ERROR_BAD_ICMP_TYPE];
 759       return NAT_NEXT_DROP;
 760     }
 761
 762   next = slow_path_ed (vm, sm, b, ip->src_address, ip->dst_address,
 763                        lookup_sport, lookup_dport, ip->protocol, rx_fib_index,
 764                        &s, node, next, thread_index, vlib_time_now (vm));
 765
 766   if (NAT_NEXT_DROP == next)
 767     goto out;
 768
 769   if (PREDICT_TRUE (!ip4_is_fragment (ip)))
 770     {
 771       ip_csum_t sum = ip_incremental_checksum_buffer (
 772         vm, b, (u8 *) icmp - (u8 *) vlib_buffer_get_current (b),
 773         ntohs (ip->length) - ip4_header_bytes (ip), 0);
 774       checksum = ~ip_csum_fold (sum);
 775       if (PREDICT_FALSE (checksum != 0 && checksum != 0xffff))
 776         {
 777           next = NAT_NEXT_DROP;
 778           goto out;
 779         }
 780     }
 781
 782 out:
 783   if (PREDICT_TRUE (next != NAT_NEXT_DROP && s))
 784     {
 785       /* Accounting */
 786       nat44_session_update_counters (
 787         s, now, vlib_buffer_length_in_chain (vm, b), thread_index);
 788       /* Per-user LRU list maintenance */
 789       nat44_session_update_lru (sm, s, thread_index);
 790     }
 791   *s_p = s;
 792   return next;
 793 }
 794
 795 static snat_session_t *
 796 nat44_ed_in2out_slowpath_unknown_proto (snat_main_t *sm, vlib_buffer_t *b,
 797                                         ip4_header_t *ip, u32 rx_fib_index,
 798                                         u32 thread_index, f64 now,
 799                                         vlib_main_t *vm,
 800                                         vlib_node_runtime_t *node)
 801 {
 802   clib_bihash_kv_8_8_t kv, value;
 803   clib_bihash_kv_16_8_t s_kv, s_value;
 804   snat_static_mapping_t *m = NULL;
 805   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 806   snat_session_t *s = NULL;
 807   u32 outside_fib_index = sm->outside_fib_index;
 808   int i;
 809   ip4_address_t new_src_addr = { 0 };
 810   ip4_address_t new_dst_addr = ip->dst_address;
 811
 812   if (PREDICT_FALSE (
 813         nat44_ed_maximum_sessions_exceeded (sm, rx_fib_index, thread_index)))
 814     {
 815       b->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 816       nat_ipfix_logging_max_sessions (thread_index,
 817                                       sm->max_translations_per_thread);
 818       nat_elog_notice (sm, "maximum sessions exceeded");
 819       return 0;
 820     }
 821
 822   switch (vec_len (sm->outside_fibs))
 823     {
 824     case 0:
 825       outside_fib_index = sm->outside_fib_index;
 826       break;
 827     case 1:
 828       outside_fib_index = sm->outside_fibs[0].fib_index;
 829       break;
 830     default:
 831       outside_fib_index = nat_outside_fib_index_lookup (sm, ip->dst_address);
 832       break;
 833     }
 834
 835   init_nat_k (&kv, ip->src_address, 0, rx_fib_index, 0);
 836
 837   /* Try to find static mapping first */
 838   if (!clib_bihash_search_8_8 (&sm->static_mapping_by_local, &kv, &value))
 839     {
 840       m = pool_elt_at_index (sm->static_mappings, value.value);
 841       new_src_addr = m->external_addr;
 842     }
 843   else
 844     {
 845       pool_foreach (s, tsm->sessions)
 846         {
 847           if (s->ext_host_addr.as_u32 == ip->dst_address.as_u32)
 848             {
 849               init_ed_k (&s_kv, s->out2in.addr, 0, ip->dst_address, 0,
 850                          outside_fib_index, ip->protocol);
 851               if (clib_bihash_search_16_8 (&sm->flow_hash, &s_kv, &s_value))
 852                 {
 853                   new_src_addr = s->out2in.addr;
 854                 }
 855               break;
 856             }
 857         }
 858
 859       if (!new_src_addr.as_u32)
 860         {
 861           for (i = 0; i < vec_len (sm->addresses); i++)
 862             {
 863               init_ed_k (&s_kv, sm->addresses[i].addr, 0, ip->dst_address, 0,
 864                          outside_fib_index, ip->protocol);
 865               if (clib_bihash_search_16_8 (&sm->flow_hash, &s_kv, &s_value))
 866                 {
 867                   new_src_addr = sm->addresses[i].addr;
 868                 }
 869             }
 870         }
 871     }
 872
 873   if (!new_src_addr.as_u32)
 874     {
 875       // could not allocate address for translation ...
 876       return 0;
 877     }
 878
 879   s = nat_ed_session_alloc (sm, thread_index, now, ip->protocol);
 880   if (!s)
 881     {
 882       b->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 883       nat_elog_warn (sm, "create NAT session failed");
 884       return 0;
 885     }
 886
 887   nat_6t_i2o_flow_init (sm, thread_index, s, ip->src_address, 0,
 888                         ip->dst_address, 0, rx_fib_index, ip->protocol);
 889   nat_6t_flow_saddr_rewrite_set (&s->i2o, new_src_addr.as_u32);
 890   nat_6t_flow_txfib_rewrite_set (&s->i2o, outside_fib_index);
 891
 892   // hairpinning?
 893   int is_hairpinning =
 894     nat44_ed_external_sm_lookup (sm, ip->dst_address, 0, NAT_PROTOCOL_OTHER,
 895                                  outside_fib_index, &new_dst_addr, NULL);
 896   s->flags |= is_hairpinning * SNAT_SESSION_FLAG_HAIRPINNING;
 897
 898   nat_6t_flow_daddr_rewrite_set (&s->i2o, new_dst_addr.as_u32);
 899   nat_6t_flow_txfib_rewrite_set (&s->i2o, outside_fib_index);
 900
 901   nat_6t_o2i_flow_init (sm, thread_index, s, new_dst_addr, 0, new_src_addr, 0,
 902                         outside_fib_index, ip->protocol);
 903   nat_6t_flow_saddr_rewrite_set (&s->o2i, ip->dst_address.as_u32);
 904   nat_6t_flow_daddr_rewrite_set (&s->o2i, ip->src_address.as_u32);
 905   nat_6t_flow_txfib_rewrite_set (&s->o2i, rx_fib_index);
 906
 907   s->ext_host_addr.as_u32 = ip->dst_address.as_u32;
 908   s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 909   s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 910   s->out2in.addr.as_u32 = new_src_addr.as_u32;
 911   s->out2in.fib_index = outside_fib_index;
 912   s->in2out.addr.as_u32 = ip->src_address.as_u32;
 913   s->in2out.fib_index = rx_fib_index;
 914   s->in2out.port = s->out2in.port = ip->protocol;
 915   if (m)
 916     s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 917
 918   if (nat_ed_ses_i2o_flow_hash_add_del (sm, thread_index, s, 1))
 919     {
 920       nat_elog_notice (sm, "in2out flow hash add failed");
 921       nat_ed_session_delete (sm, s, thread_index, 1);
 922       return NULL;
 923     }
 924
 925   if (nat_ed_ses_o2i_flow_hash_add_del (sm, thread_index, s, 1))
 926     {
 927       nat_elog_notice (sm, "out2in flow hash add failed");
 928       nat_ed_session_delete (sm, s, thread_index, 1);
 929       return NULL;
 930     }
 931
 932   per_vrf_sessions_register_session (s, thread_index);
 933
 934   /* Accounting */
 935   nat44_session_update_counters (s, now, vlib_buffer_length_in_chain (vm, b),
 936                                  thread_index);
 937   /* Per-user LRU list maintenance */
 938   nat44_session_update_lru (sm, s, thread_index);
 939
 940   return s;
 941 }
 942
 943 static inline uword
 944 nat44_ed_in2out_fast_path_node_fn_inline (vlib_main_t *vm,
 945                                           vlib_node_runtime_t *node,
 946                                           vlib_frame_t *frame,
 947                                           int is_output_feature,
 948                                           int is_multi_worker)
 949 {
 950   u32 n_left_from, *from;
 951   snat_main_t *sm = &snat_main;
 952   f64 now = vlib_time_now (vm);
 953   u32 thread_index = vm->thread_index;
 954   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 955   u32 def_slow = is_output_feature ? NAT_NEXT_IN2OUT_ED_OUTPUT_SLOW_PATH
 956     : NAT_NEXT_IN2OUT_ED_SLOW_PATH;
 957
 958   from = vlib_frame_vector_args (frame);
 959   n_left_from = frame->n_vectors;
 960
 961   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b = bufs;
 962   u16 nexts[VLIB_FRAME_SIZE], *next = nexts;
 963   vlib_get_buffers (vm, from, b, n_left_from);
 964
 965   while (n_left_from > 0)
 966     {
 967       vlib_buffer_t *b0;
 968       u32 sw_if_index0, rx_fib_index0, iph_offset0 = 0;
 969       nat_protocol_t proto0;
 970       ip4_header_t *ip0;
 971       snat_session_t *s0 = 0;
 972       clib_bihash_kv_16_8_t kv0, value0;
 973       nat_translation_error_e translation_error = NAT_ED_TRNSL_ERR_SUCCESS;
 974       nat_6t_flow_t *f = 0;
 975       nat_6t_t lookup;
 976       int lookup_skipped = 0;
 977
 978       b0 = *b;
 979       b++;
 980
 981       /* Prefetch next iteration. */
 982       if (PREDICT_TRUE (n_left_from >= 2))
 983         {
 984           vlib_buffer_t *p2;
 985
 986           p2 = *b;
 987
 988           vlib_prefetch_buffer_header (p2, LOAD);
 989
 990           CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, LOAD);
 991         }
 992
 993       if (is_output_feature)
 994         {
 995           iph_offset0 = vnet_buffer (b0)->ip.reass.save_rewrite_length;
 996         }
 997
 998       next[0] = vnet_buffer2 (b0)->nat.arc_next;
 999
1000       ip0 =
1001         (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) + iph_offset0);
1002
1003       sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1004       rx_fib_index0 =
1005         fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4, sw_if_index0);
1006       lookup.fib_index = rx_fib_index0;
1007
1008       if (PREDICT_FALSE (ip0->ttl == 1))
1009         {
1010           vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1011           icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1012                                        ICMP4_time_exceeded_ttl_exceeded_in_transit,
1013                                        0);
1014           next[0] = NAT_NEXT_ICMP_ERROR;
1015           goto trace0;
1016         }
1017
1018       proto0 = ip_proto_to_nat_proto (ip0->protocol);
1019
1020       if (is_output_feature)
1021         {
1022           if (PREDICT_FALSE
1023               (nat_not_translate_output_feature_fwd
1024                (sm, ip0, thread_index, now, vm, b0)))
1025             goto trace0;
1026         }
1027
1028       if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
1029         {
1030           if (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
1031                 ICMP4_echo_request &&
1032               vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
1033                 ICMP4_echo_reply &&
1034               !icmp_type_is_error_message (
1035                 vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags))
1036             {
1037               b0->error = node->errors[NAT_IN2OUT_ED_ERROR_BAD_ICMP_TYPE];
1038               next[0] = NAT_NEXT_DROP;
1039               goto trace0;
1040             }
1041           int err = nat_get_icmp_session_lookup_values (
1042             b0, ip0, &lookup.saddr, &lookup.sport, &lookup.daddr,
1043             &lookup.dport, &lookup.proto);
1044           if (err != 0)
1045             {
1046               b0->error = node->errors[err];
1047               next[0] = NAT_NEXT_DROP;
1048               goto trace0;
1049             }
1050         }
1051       else
1052         {
1053           lookup.proto = ip0->protocol;
1054           lookup.saddr.as_u32 = ip0->src_address.as_u32;
1055           lookup.daddr.as_u32 = ip0->dst_address.as_u32;
1056           lookup.sport = vnet_buffer (b0)->ip.reass.l4_src_port;
1057           lookup.dport = vnet_buffer (b0)->ip.reass.l4_dst_port;
1058         }
1059
1060       /* there might be a stashed index in vnet_buffer2 from handoff or
1061        * classify node, see if it can be used */
1062       if (is_multi_worker &&
1063           !pool_is_free_index (tsm->sessions,
1064                                vnet_buffer2 (b0)->nat.cached_session_index))
1065         {
1066           s0 = pool_elt_at_index (tsm->sessions,
1067                                   vnet_buffer2 (b0)->nat.cached_session_index);
1068           if (PREDICT_TRUE (
1069                 nat_6t_t_eq (&s0->i2o.match, &lookup)
1070                 // for some hairpinning cases there are two "i2i" flows instead
1071                 // of i2o and o2i as both hosts are on inside
1072                 || (s0->flags & SNAT_SESSION_FLAG_HAIRPINNING &&
1073                     nat_6t_t_eq (&s0->o2i.match, &lookup))))
1074             {
1075               /* yes, this is the droid we're looking for */
1076               lookup_skipped = 1;
1077               goto skip_lookup;
1078             }
1079           s0 = NULL;
1080         }
1081
1082       init_ed_k (&kv0, lookup.saddr, lookup.sport, lookup.daddr, lookup.dport,
1083                  lookup.fib_index, lookup.proto);
1084
1085       // lookup flow
1086       if (clib_bihash_search_16_8 (&sm->flow_hash, &kv0, &value0))
1087         {
1088           // flow does not exist go slow path
1089           next[0] = def_slow;
1090           goto trace0;
1091         }
1092
1093       ASSERT (thread_index == ed_value_get_thread_index (&value0));
1094       s0 =
1095         pool_elt_at_index (tsm->sessions,
1096                            ed_value_get_session_index (&value0));
1097
1098     skip_lookup:
1099
1100       if (PREDICT_FALSE (per_vrf_sessions_is_expired (s0, thread_index)))
1101         {
1102           // session is closed, go slow path
1103           nat_free_session_data (sm, s0, thread_index, 0);
1104           nat_ed_session_delete (sm, s0, thread_index, 1);
1105           next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
1106           goto trace0;
1107         }
1108
1109       if (s0->tcp_closed_timestamp)
1110         {
1111           if (now >= s0->tcp_closed_timestamp)
1112             {
1113               // session is closed, go slow path, freed in slow path
1114               next[0] = def_slow;
1115             }
1116           else
1117             {
1118               // session in transitory timeout, drop
1119               b0->error = node->errors[NAT_IN2OUT_ED_ERROR_TCP_CLOSED];
1120               next[0] = NAT_NEXT_DROP;
1121             }
1122           goto trace0;
1123         }
1124
1125       // drop if session expired
1126       u64 sess_timeout_time;
1127       sess_timeout_time =
1128         s0->last_heard + (f64) nat44_session_get_timeout (sm, s0);
1129       if (now >= sess_timeout_time)
1130         {
1131           nat_free_session_data (sm, s0, thread_index, 0);
1132           nat_ed_session_delete (sm, s0, thread_index, 1);
1133           // session is closed, go slow path
1134           next[0] = def_slow;
1135           goto trace0;
1136         }
1137
1138       b0->flags |= VNET_BUFFER_F_IS_NATED;
1139
1140       if (nat_6t_t_eq (&s0->i2o.match, &lookup))
1141         {
1142           f = &s0->i2o;
1143         }
1144       else if (s0->flags & SNAT_SESSION_FLAG_HAIRPINNING &&
1145                nat_6t_t_eq (&s0->o2i.match, &lookup))
1146         {
1147           f = &s0->o2i;
1148         }
1149       else
1150         {
1151           translation_error = NAT_ED_TRNSL_ERR_FLOW_MISMATCH;
1152           nat_free_session_data (sm, s0, thread_index, 0);
1153           nat_ed_session_delete (sm, s0, thread_index, 1);
1154           next[0] = NAT_NEXT_DROP;
1155           goto trace0;
1156         }
1157
1158       if (NAT_ED_TRNSL_ERR_SUCCESS !=
1159           (translation_error = nat_6t_flow_buf_translate (
1160              sm, b0, ip0, f, proto0, is_output_feature)))
1161         {
1162           nat_free_session_data (sm, s0, thread_index, 0);
1163           nat_ed_session_delete (sm, s0, thread_index, 1);
1164           next[0] = NAT_NEXT_DROP;
1165           goto trace0;
1166         }
1167
1168       switch (proto0)
1169         {
1170         case NAT_PROTOCOL_TCP:
1171           vlib_increment_simple_counter (&sm->counters.fastpath.in2out.tcp,
1172                                          thread_index, sw_if_index0, 1);
1173           nat44_set_tcp_session_state_i2o (sm, now, s0, b0, thread_index);
1174           break;
1175         case NAT_PROTOCOL_UDP:
1176           vlib_increment_simple_counter (&sm->counters.fastpath.in2out.udp,
1177                                          thread_index, sw_if_index0, 1);
1178           break;
1179         case NAT_PROTOCOL_ICMP:
1180           vlib_increment_simple_counter (&sm->counters.fastpath.in2out.icmp,
1181                                          thread_index, sw_if_index0, 1);
1182           break;
1183         case NAT_PROTOCOL_OTHER:
1184           vlib_increment_simple_counter (&sm->counters.fastpath.in2out.other,
1185                                          thread_index, sw_if_index0, 1);
1186           break;
1187         }
1188
1189       /* Accounting */
1190       nat44_session_update_counters (s0, now,
1191                                      vlib_buffer_length_in_chain (vm, b0),
1192                                      thread_index);
1193       /* Per-user LRU list maintenance */
1194       nat44_session_update_lru (sm, s0, thread_index);
1195
1196     trace0:
1197       if (PREDICT_FALSE
1198           ((node->flags & VLIB_NODE_FLAG_TRACE)
1199            && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1200         {
1201           nat_in2out_ed_trace_t *t =
1202             vlib_add_trace (vm, node, b0, sizeof (*t));
1203           t->sw_if_index = sw_if_index0;
1204           t->next_index = next[0];
1205           t->is_slow_path = 0;
1206           t->translation_error = translation_error;
1207           t->lookup_skipped = lookup_skipped;
1208           clib_memcpy (&t->search_key, &kv0, sizeof (t->search_key));
1209
1210           if (s0)
1211             {
1212               t->session_index = s0 - tsm->sessions;
1213               clib_memcpy (&t->i2of, &s0->i2o, sizeof (t->i2of));
1214               clib_memcpy (&t->o2if, &s0->o2i, sizeof (t->o2if));
1215               t->translation_via_i2of = (&s0->i2o == f);
1216             }
1217           else
1218             {
1219               t->session_index = ~0;
1220             }
1221         }
1222
1223       if (next[0] == NAT_NEXT_DROP)
1224         {
1225           vlib_increment_simple_counter (&sm->counters.fastpath.in2out.drops,
1226                                          thread_index, sw_if_index0, 1);
1227         }
1228
1229       n_left_from--;
1230       next++;
1231     }
1232
1233   vlib_buffer_enqueue_to_next (vm, node, from, (u16 *) nexts,
1234                                frame->n_vectors);
1235   return frame->n_vectors;
1236 }
1237
1238 static inline uword
1239 nat44_ed_in2out_slow_path_node_fn_inline (vlib_main_t * vm,
1240                                           vlib_node_runtime_t * node,
1241                                           vlib_frame_t * frame,
1242                                           int is_output_feature)
1243 {
1244   u32 n_left_from, *from;
1245   snat_main_t *sm = &snat_main;
1246   f64 now = vlib_time_now (vm);
1247   u32 thread_index = vm->thread_index;
1248   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
1249
1250   from = vlib_frame_vector_args (frame);
1251   n_left_from = frame->n_vectors;
1252
1253   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b = bufs;
1254   u16 nexts[VLIB_FRAME_SIZE], *next = nexts;
1255   vlib_get_buffers (vm, from, b, n_left_from);
1256
1257   while (n_left_from > 0)
1258     {
1259       vlib_buffer_t *b0;
1260       u32 sw_if_index0, rx_fib_index0, iph_offset0 = 0;
1261       nat_protocol_t proto0;
1262       ip4_header_t *ip0;
1263       udp_header_t *udp0;
1264       icmp46_header_t *icmp0;
1265       snat_session_t *s0 = 0;
1266       clib_bihash_kv_16_8_t kv0, value0;
1267       int translation_error = NAT_ED_TRNSL_ERR_SUCCESS;
1268
1269       b0 = *b;
1270
1271       if (is_output_feature)
1272         iph_offset0 = vnet_buffer (b0)->ip.reass.save_rewrite_length;
1273
1274       next[0] = vnet_buffer2 (b0)->nat.arc_next;
1275
1276       ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
1277                               iph_offset0);
1278
1279       sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1280       rx_fib_index0 =
1281         fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4, sw_if_index0);
1282
1283       if (PREDICT_FALSE (ip0->ttl == 1))
1284         {
1285           vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1286           icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1287                                        ICMP4_time_exceeded_ttl_exceeded_in_transit,
1288                                        0);
1289           next[0] = NAT_NEXT_ICMP_ERROR;
1290           goto trace0;
1291         }
1292
1293       udp0 = ip4_next_header (ip0);
1294       icmp0 = (icmp46_header_t *) udp0;
1295       proto0 = ip_proto_to_nat_proto (ip0->protocol);
1296
1297       if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
1298         {
1299           s0 = nat44_ed_in2out_slowpath_unknown_proto (
1300             sm, b0, ip0, rx_fib_index0, thread_index, now, vm, node);
1301           if (!s0)
1302             next[0] = NAT_NEXT_DROP;
1303
1304           if (NAT_ED_TRNSL_ERR_SUCCESS !=
1305               (translation_error = nat_6t_flow_buf_translate (
1306                  sm, b0, ip0, &s0->i2o, proto0, is_output_feature)))
1307             {
1308               goto trace0;
1309             }
1310
1311           vlib_increment_simple_counter (&sm->counters.slowpath.in2out.other,
1312                                          thread_index, sw_if_index0, 1);
1313           goto trace0;
1314         }
1315
1316       if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
1317         {
1318           next[0] = icmp_in2out_ed_slow_path (sm, b0, ip0, icmp0, sw_if_index0,
1319                                               rx_fib_index0, node, next[0],
1320                                               now, thread_index, proto0, &s0);
1321           if (NAT_NEXT_DROP != next[0] && s0 &&
1322               NAT_ED_TRNSL_ERR_SUCCESS !=
1323                 (translation_error = nat_6t_flow_buf_translate (
1324                    sm, b0, ip0, &s0->i2o, proto0, is_output_feature)))
1325             {
1326               goto trace0;
1327             }
1328
1329           vlib_increment_simple_counter (&sm->counters.slowpath.in2out.icmp,
1330                                          thread_index, sw_if_index0, 1);
1331           goto trace0;
1332         }
1333
1334       init_ed_k (&kv0, ip0->src_address,
1335                  vnet_buffer (b0)->ip.reass.l4_src_port, ip0->dst_address,
1336                  vnet_buffer (b0)->ip.reass.l4_dst_port, rx_fib_index0,
1337                  ip0->protocol);
1338       if (!clib_bihash_search_16_8 (&sm->flow_hash, &kv0, &value0))
1339         {
1340           ASSERT (thread_index == ed_value_get_thread_index (&value0));
1341           s0 =
1342             pool_elt_at_index (tsm->sessions,
1343                                ed_value_get_session_index (&value0));
1344
1345           if (s0->tcp_closed_timestamp && now >= s0->tcp_closed_timestamp)
1346             {
1347               nat_free_session_data (sm, s0, thread_index, 0);
1348               nat_ed_session_delete (sm, s0, thread_index, 1);
1349               s0 = NULL;
1350             }
1351         }
1352
1353       if (!s0)
1354         {
1355           if (is_output_feature)
1356             {
1357               if (PREDICT_FALSE
1358                   (nat44_ed_not_translate_output_feature
1359                    (sm, ip0, vnet_buffer (b0)->ip.reass.l4_src_port,
1360                     vnet_buffer (b0)->ip.reass.l4_dst_port, thread_index,
1361                     sw_if_index0, vnet_buffer (b0)->sw_if_index[VLIB_TX],
1362                     now)))
1363                 goto trace0;
1364
1365               /*
1366                * Send DHCP packets to the ipv4 stack, or we won't
1367                * be able to use dhcp client on the outside interface
1368                */
1369               if (PREDICT_FALSE
1370                   (proto0 == NAT_PROTOCOL_UDP
1371                    && (vnet_buffer (b0)->ip.reass.l4_dst_port ==
1372                        clib_host_to_net_u16 (UDP_DST_PORT_dhcp_to_server))
1373                    && ip0->dst_address.as_u32 == 0xffffffff))
1374                 goto trace0;
1375             }
1376           else
1377             {
1378               if (PREDICT_FALSE (nat44_ed_not_translate (
1379                     vm, sm, node, sw_if_index0, b0, ip0, proto0, rx_fib_index0,
1380                     thread_index)))
1381                 goto trace0;
1382             }
1383
1384           next[0] = slow_path_ed (
1385             vm, sm, b0, ip0->src_address, ip0->dst_address,
1386             vnet_buffer (b0)->ip.reass.l4_src_port,
1387             vnet_buffer (b0)->ip.reass.l4_dst_port, ip0->protocol,
1388             rx_fib_index0, &s0, node, next[0], thread_index, now);
1389
1390           if (PREDICT_FALSE (next[0] == NAT_NEXT_DROP))
1391             goto trace0;
1392
1393           if (PREDICT_FALSE (!s0))
1394             goto trace0;
1395
1396         }
1397
1398       b0->flags |= VNET_BUFFER_F_IS_NATED;
1399
1400       if (NAT_ED_TRNSL_ERR_SUCCESS !=
1401           (translation_error = nat_6t_flow_buf_translate (
1402              sm, b0, ip0, &s0->i2o, proto0, is_output_feature)))
1403         {
1404           nat_free_session_data (sm, s0, thread_index, 0);
1405           nat_ed_session_delete (sm, s0, thread_index, 1);
1406           s0 = NULL;
1407           goto trace0;
1408         }
1409
1410       if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
1411         {
1412           vlib_increment_simple_counter (&sm->counters.slowpath.in2out.tcp,
1413                                          thread_index, sw_if_index0, 1);
1414           nat44_set_tcp_session_state_i2o (sm, now, s0, b0, thread_index);
1415         }
1416       else
1417         {
1418           vlib_increment_simple_counter (&sm->counters.slowpath.in2out.udp,
1419                                          thread_index, sw_if_index0, 1);
1420         }
1421
1422       /* Accounting */
1423       nat44_session_update_counters (s0, now,
1424                                      vlib_buffer_length_in_chain
1425                                      (vm, b0), thread_index);
1426       /* Per-user LRU list maintenance */
1427       nat44_session_update_lru (sm, s0, thread_index);
1428
1429     trace0:
1430       if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1431                          && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1432         {
1433           nat_in2out_ed_trace_t *t =
1434             vlib_add_trace (vm, node, b0, sizeof (*t));
1435           t->sw_if_index = sw_if_index0;
1436           t->next_index = next[0];
1437           t->is_slow_path = 1;
1438           t->translation_error = translation_error;
1439           clib_memcpy (&t->search_key, &kv0, sizeof (t->search_key));
1440
1441           if (s0)
1442             {
1443               t->session_index = s0 - tsm->sessions;
1444               clib_memcpy (&t->i2of, &s0->i2o, sizeof (t->i2of));
1445               clib_memcpy (&t->o2if, &s0->o2i, sizeof (t->o2if));
1446               t->translation_via_i2of = 1;
1447             }
1448
1449           else
1450             {
1451               t->session_index = ~0;
1452             }
1453         }
1454
1455       if (next[0] == NAT_NEXT_DROP)
1456         {
1457           vlib_increment_simple_counter (&sm->counters.slowpath.in2out.drops,
1458                                          thread_index, sw_if_index0, 1);
1459         }
1460
1461       n_left_from--;
1462       next++;
1463       b++;
1464     }
1465
1466   vlib_buffer_enqueue_to_next (vm, node, from, (u16 *) nexts,
1467                                frame->n_vectors);
1468
1469   return frame->n_vectors;
1470 }
1471
1472 VLIB_NODE_FN (nat44_ed_in2out_node) (vlib_main_t * vm,
1473                                      vlib_node_runtime_t * node,
1474                                      vlib_frame_t * frame)
1475 {
1476   if (snat_main.num_workers > 1)
1477     {
1478       return nat44_ed_in2out_fast_path_node_fn_inline (vm, node, frame, 0, 1);
1479     }
1480   else
1481     {
1482       return nat44_ed_in2out_fast_path_node_fn_inline (vm, node, frame, 0, 0);
1483     }
1484 }
1485
1486 VLIB_REGISTER_NODE (nat44_ed_in2out_node) = {
1487   .name = "nat44-ed-in2out",
1488   .vector_size = sizeof (u32),
1489   .sibling_of = "nat-default",
1490   .format_trace = format_nat_in2out_ed_trace,
1491   .type = VLIB_NODE_TYPE_INTERNAL,
1492   .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
1493   .error_strings = nat_in2out_ed_error_strings,
1494   .runtime_data_bytes = sizeof (snat_runtime_t),
1495 };
1496
1497 VLIB_NODE_FN (nat44_ed_in2out_output_node) (vlib_main_t * vm,
1498                                             vlib_node_runtime_t * node,
1499                                             vlib_frame_t * frame)
1500 {
1501   if (snat_main.num_workers > 1)
1502     {
1503       return nat44_ed_in2out_fast_path_node_fn_inline (vm, node, frame, 1, 1);
1504     }
1505   else
1506     {
1507       return nat44_ed_in2out_fast_path_node_fn_inline (vm, node, frame, 1, 0);
1508     }
1509 }
1510
1511 VLIB_REGISTER_NODE (nat44_ed_in2out_output_node) = {
1512   .name = "nat44-ed-in2out-output",
1513   .vector_size = sizeof (u32),
1514   .sibling_of = "nat-default",
1515   .format_trace = format_nat_in2out_ed_trace,
1516   .type = VLIB_NODE_TYPE_INTERNAL,
1517   .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
1518   .error_strings = nat_in2out_ed_error_strings,
1519   .runtime_data_bytes = sizeof (snat_runtime_t),
1520 };
1521
1522 VLIB_NODE_FN (nat44_ed_in2out_slowpath_node) (vlib_main_t * vm,
1523                                               vlib_node_runtime_t *
1524                                               node, vlib_frame_t * frame)
1525 {
1526   return nat44_ed_in2out_slow_path_node_fn_inline (vm, node, frame, 0);
1527 }
1528
1529 VLIB_REGISTER_NODE (nat44_ed_in2out_slowpath_node) = {
1530   .name = "nat44-ed-in2out-slowpath",
1531   .vector_size = sizeof (u32),
1532   .sibling_of = "nat-default",
1533   .format_trace = format_nat_in2out_ed_trace,
1534   .type = VLIB_NODE_TYPE_INTERNAL,
1535   .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
1536   .error_strings = nat_in2out_ed_error_strings,
1537   .runtime_data_bytes = sizeof (snat_runtime_t),
1538 };
1539
1540 VLIB_NODE_FN (nat44_ed_in2out_output_slowpath_node) (vlib_main_t * vm,
1541                                                      vlib_node_runtime_t
1542                                                      * node,
1543                                                      vlib_frame_t * frame)
1544 {
1545   return nat44_ed_in2out_slow_path_node_fn_inline (vm, node, frame, 1);
1546 }
1547
1548 VLIB_REGISTER_NODE (nat44_ed_in2out_output_slowpath_node) = {
1549   .name = "nat44-ed-in2out-output-slowpath",
1550   .vector_size = sizeof (u32),
1551   .sibling_of = "nat-default",
1552   .format_trace = format_nat_in2out_ed_trace,
1553   .type = VLIB_NODE_TYPE_INTERNAL,
1554   .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
1555   .error_strings = nat_in2out_ed_error_strings,
1556   .runtime_data_bytes = sizeof (snat_runtime_t),
1557 };
1558
1559 static u8 *
1560 format_nat_pre_trace (u8 * s, va_list * args)
1561 {
1562   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1563   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1564   nat_pre_trace_t *t = va_arg (*args, nat_pre_trace_t *);
1565   return format (s, "in2out next_index %d arc_next_index %d", t->next_index,
1566                  t->arc_next_index);
1567 }
1568
1569 VLIB_NODE_FN (nat_pre_in2out_node)
1570   (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
1571 {
1572   return nat_pre_node_fn_inline (vm, node, frame,
1573                                  NAT_NEXT_IN2OUT_ED_FAST_PATH);
1574 }
1575
1576 VLIB_NODE_FN (nat_pre_in2out_output_node)
1577   (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
1578 {
1579   return nat_pre_node_fn_inline (vm, node, frame,
1580                                  NAT_NEXT_IN2OUT_ED_OUTPUT_FAST_PATH);
1581 }
1582
1583 VLIB_REGISTER_NODE (nat_pre_in2out_node) = {
1584   .name = "nat-pre-in2out",
1585   .vector_size = sizeof (u32),
1586   .sibling_of = "nat-default",
1587   .format_trace = format_nat_pre_trace,
1588   .type = VLIB_NODE_TYPE_INTERNAL,
1589   .n_errors = 0,
1590 };
1591
1592 VLIB_REGISTER_NODE (nat_pre_in2out_output_node) = {
1593   .name = "nat-pre-in2out-output",
1594   .vector_size = sizeof (u32),
1595   .sibling_of = "nat-default",
1596   .format_trace = format_nat_pre_trace,
1597   .type = VLIB_NODE_TYPE_INTERNAL,
1598   .n_errors = 0,
1599 };
1600
1601 /*
1602  * fd.io coding-style-patch-verification: ON
1603  *
1604  * Local Variables:
1605  * eval: (c-set-style "gnu")
1606  * End:
1607  */