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 #include <nat/nat44/ed_inlines.h>
  35 #include <nat/lib/nat_inlines.h>
  36
  37 static char *nat_in2out_ed_error_strings[] = {
  38 #define _(sym,string) string,
  39   foreach_nat_in2out_ed_error
  40 #undef _
  41 };
  42
  43 typedef struct
  44 {
  45   u32 sw_if_index;
  46   u32 next_index;
  47   u32 session_index;
  48   u32 is_slow_path;
  49 } nat_in2out_ed_trace_t;
  50
  51 static u8 *
  52 format_nat_in2out_ed_trace (u8 * s, va_list * args)
  53 {
  54   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  55   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  56   nat_in2out_ed_trace_t *t = va_arg (*args, nat_in2out_ed_trace_t *);
  57   char *tag;
  58
  59   tag =
  60     t->is_slow_path ? "NAT44_IN2OUT_ED_SLOW_PATH" :
  61     "NAT44_IN2OUT_ED_FAST_PATH";
  62
  63   s = format (s, "%s: sw_if_index %d, next index %d, session %d", tag,
  64               t->sw_if_index, t->next_index, t->session_index);
  65
  66   return s;
  67 }
  68
  69 #ifndef CLIB_MARCH_VARIANT
  70 int
  71 nat44_i2o_ed_is_idle_session_cb (clib_bihash_kv_16_8_t * kv, void *arg)
  72 {
  73   snat_main_t *sm = &snat_main;
  74   nat44_is_idle_session_ctx_t *ctx = arg;
  75   snat_session_t *s;
  76   u64 sess_timeout_time;
  77   u8 proto;
  78   u16 r_port, l_port;
  79   ip4_address_t *l_addr, *r_addr;
  80   u32 fib_index;
  81   clib_bihash_kv_16_8_t ed_kv;
  82   int i;
  83   snat_address_t *a;
  84   snat_main_per_thread_data_t *tsm = vec_elt_at_index (sm->per_thread_data,
  85                                                        ctx->thread_index);
  86
  87   ASSERT (ctx->thread_index == ed_value_get_thread_index (kv));
  88   s = pool_elt_at_index (tsm->sessions, ed_value_get_session_index (kv));
  89   sess_timeout_time = s->last_heard + (f64) nat44_session_get_timeout (sm, s);
  90   if (ctx->now >= sess_timeout_time)
  91     {
  92       if (is_fwd_bypass_session (s))
  93         goto delete;
  94
  95       l_addr = &s->out2in.addr;
  96       r_addr = &s->ext_host_addr;
  97       fib_index = s->out2in.fib_index;
  98       if (snat_is_unk_proto_session (s))
  99         {
 100           proto = s->in2out.port;
 101           r_port = 0;
 102           l_port = 0;
 103         }
 104       else
 105         {
 106           proto = nat_proto_to_ip_proto (s->nat_proto);
 107           l_port = s->out2in.port;
 108           r_port = s->ext_host_port;
 109         }
 110       init_ed_k (&ed_kv, *l_addr, l_port, *r_addr, r_port, fib_index, proto);
 111       if (clib_bihash_add_del_16_8 (&sm->out2in_ed, &ed_kv, 0))
 112         nat_elog_warn ("out2in_ed key del failed");
 113
 114       if (snat_is_unk_proto_session (s))
 115         goto delete;
 116
 117       snat_ipfix_logging_nat44_ses_delete (ctx->thread_index,
 118                                            s->in2out.addr.as_u32,
 119                                            s->out2in.addr.as_u32,
 120                                            s->nat_proto,
 121                                            s->in2out.port,
 122                                            s->out2in.port,
 123                                            s->in2out.fib_index);
 124
 125       nat_syslog_nat44_sdel (s->user_index, s->in2out.fib_index,
 126                              &s->in2out.addr, s->in2out.port,
 127                              &s->ext_host_nat_addr, s->ext_host_nat_port,
 128                              &s->out2in.addr, s->out2in.port,
 129                              &s->ext_host_addr, s->ext_host_port,
 130                              s->nat_proto, is_twice_nat_session (s));
 131
 132       nat_ha_sdel (&s->out2in.addr, s->out2in.port, &s->ext_host_addr,
 133                    s->ext_host_port, s->nat_proto, s->out2in.fib_index,
 134                    ctx->thread_index);
 135
 136       if (is_twice_nat_session (s))
 137         {
 138           for (i = 0; i < vec_len (sm->twice_nat_addresses); i++)
 139             {
 140               // TODO FIXME this is obviously broken - which address should be
 141               // freed here?!
 142               a = sm->twice_nat_addresses + i;
 143               if (a->addr.as_u32 == s->ext_host_nat_addr.as_u32)
 144                 {
 145                   snat_free_outside_address_and_port (sm->twice_nat_addresses,
 146                                                       ctx->thread_index,
 147                                                       &s->ext_host_nat_addr,
 148                                                       s->ext_host_nat_port,
 149                                                       s->nat_proto);
 150                   break;
 151                 }
 152             }
 153         }
 154
 155       if (snat_is_session_static (s))
 156         goto delete;
 157
 158       snat_free_outside_address_and_port (sm->addresses, ctx->thread_index,
 159                                           &s->out2in.addr, s->out2in.port,
 160                                           s->nat_proto);
 161     delete:
 162       nat_ed_session_delete (sm, s, ctx->thread_index, 1);
 163       return 1;
 164     }
 165
 166   return 0;
 167 }
 168 #endif
 169
 170 static inline u32
 171 icmp_in2out_ed_slow_path (snat_main_t * sm, vlib_buffer_t * b0,
 172                           ip4_header_t * ip0, icmp46_header_t * icmp0,
 173                           u32 sw_if_index0, u32 rx_fib_index0,
 174                           vlib_node_runtime_t * node, u32 next0, f64 now,
 175                           u32 thread_index, snat_session_t ** p_s0)
 176 {
 177   vlib_main_t *vm = vlib_get_main ();
 178
 179   next0 = icmp_in2out (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
 180                        next0, thread_index, p_s0, 0);
 181   snat_session_t *s0 = *p_s0;
 182   if (PREDICT_TRUE (next0 != NAT_NEXT_DROP && s0))
 183     {
 184       /* Accounting */
 185       nat44_session_update_counters (s0, now,
 186                                      vlib_buffer_length_in_chain
 187                                      (vm, b0), thread_index);
 188       /* Per-user LRU list maintenance */
 189       nat44_session_update_lru (sm, s0, thread_index);
 190     }
 191   return next0;
 192 }
 193
 194 static int
 195 nat_ed_alloc_addr_and_port (snat_main_t * sm, u32 rx_fib_index,
 196                             u32 nat_proto, u32 thread_index,
 197                             ip4_address_t r_addr, u16 r_port, u8 proto,
 198                             u16 port_per_thread, u32 snat_thread_index,
 199                             snat_session_t * s,
 200                             ip4_address_t * outside_addr,
 201                             u16 * outside_port,
 202                             clib_bihash_kv_16_8_t * out2in_ed_kv)
 203 {
 204   int i;
 205   snat_address_t *a, *ga = 0;
 206   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 207
 208   const u16 port_thread_offset = (port_per_thread * snat_thread_index) + 1024;
 209
 210   for (i = 0; i < vec_len (sm->addresses); i++)
 211     {
 212       a = sm->addresses + i;
 213       switch (nat_proto)
 214         {
 215 #define _(N, j, n, unused)                                                   \
 216   case NAT_PROTOCOL_##N:                                                     \
 217     if (a->fib_index == rx_fib_index)                                        \
 218       {                                                                      \
 219         /* first try port suggested by caller */                             \
 220         u16 port = clib_net_to_host_u16 (*outside_port);                   \
 221         u16 port_offset = port - port_thread_offset;                         \
 222         if (port <= port_thread_offset ||                                    \
 223             port > port_thread_offset + port_per_thread)                     \
 224           {                                                                  \
 225             /* need to pick a different port, suggested port doesn't fit in  \
 226              * this thread's port range */                                   \
 227             port_offset = snat_random_port (1, port_per_thread);             \
 228             port = port_thread_offset + port_offset;                         \
 229           }                                                                  \
 230         u16 attempts = port_per_thread;                                      \
 231         do                                                                   \
 232           {                                                                  \
 233             init_ed_kv (out2in_ed_kv, a->addr, clib_host_to_net_u16 (port),  \
 234                         r_addr, r_port, s->out2in.fib_index, proto,          \
 235                         thread_index, s - tsm->sessions);                    \
 236             int rv = clib_bihash_add_del_16_8 (&sm->out2in_ed, out2in_ed_kv, \
 237                                                2 /* is_add */);              \
 238             if (0 == rv)                                                     \
 239               {                                                              \
 240                 ++a->busy_##n##_port_refcounts[port];                        \
 241                 a->busy_##n##_ports_per_thread[thread_index]++;              \
 242                 a->busy_##n##_ports++;                                       \
 243                 *outside_addr = a->addr;                                   \
 244                 *outside_port = clib_host_to_net_u16 (port);               \
 245                 return 0;                                                    \
 246               }                                                              \
 247             port_offset = (port_offset + 1) % port_per_thread;               \
 248             port = port_thread_offset + port_offset;                         \
 249             --attempts;                                                      \
 250           }                                                                  \
 251         while (attempts > 0);                                                \
 252       }                                                                      \
 253     else if (a->fib_index == ~0)                                             \
 254       {                                                                      \
 255         ga = a;                                                              \
 256       }                                                                      \
 257     break;
 258
 259           foreach_nat_protocol;
 260         default:
 261           nat_elog_info ("unknown protocol");
 262           return 1;
 263         }
 264     }
 265
 266   if (ga)
 267     {
 268       /* fake fib_index to reuse macro */
 269       rx_fib_index = ~0;
 270       a = ga;
 271       switch (nat_proto)
 272         {
 273           foreach_nat_protocol;
 274         default:
 275           nat_elog_info ("unknown protocol");
 276           return 1;
 277         }
 278     }
 279
 280 #undef _
 281
 282   /* Totally out of translations to use... */
 283   snat_ipfix_logging_addresses_exhausted (thread_index, 0);
 284   return 1;
 285 }
 286
 287 static_always_inline u32
 288 nat_outside_fib_index_lookup (snat_main_t * sm, ip4_address_t addr)
 289 {
 290   fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
 291   nat_outside_fib_t *outside_fib;
 292   fib_prefix_t pfx = {
 293     .fp_proto = FIB_PROTOCOL_IP4,
 294     .fp_len = 32,
 295     .fp_addr = {.ip4.as_u32 = addr.as_u32,}
 296     ,
 297   };
 298   // TODO: multiple vrfs none can resolve addr
 299   /* *INDENT-OFF* */
 300   vec_foreach (outside_fib, sm->outside_fibs)
 301     {
 302       fei = fib_table_lookup (outside_fib->fib_index, &pfx);
 303       if (FIB_NODE_INDEX_INVALID != fei)
 304         {
 305           if (fib_entry_get_resolving_interface (fei) != ~0)
 306             {
 307               return outside_fib->fib_index;
 308             }
 309         }
 310     }
 311   /* *INDENT-ON* */
 312   return ~0;
 313 }
 314
 315 static u32
 316 slow_path_ed (snat_main_t * sm,
 317               vlib_buffer_t * b,
 318               ip4_address_t l_addr,
 319               ip4_address_t r_addr,
 320               u16 l_port,
 321               u16 r_port,
 322               u8 proto,
 323               u32 rx_fib_index,
 324               snat_session_t ** sessionp,
 325               vlib_node_runtime_t * node, u32 next, u32 thread_index, f64 now)
 326 {
 327   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 328   clib_bihash_kv_16_8_t out2in_ed_kv;
 329   nat44_is_idle_session_ctx_t ctx;
 330   ip4_address_t outside_addr;
 331   u16 outside_port;
 332   u8 identity_nat;
 333
 334   u32 nat_proto = ip_proto_to_nat_proto (proto);
 335   snat_session_t *s = NULL;
 336   lb_nat_type_t lb = 0;
 337
 338   if (PREDICT_TRUE (nat_proto == NAT_PROTOCOL_TCP))
 339     {
 340       if (PREDICT_FALSE
 341           (!tcp_flags_is_init
 342            (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags)))
 343         {
 344           b->error = node->errors[NAT_IN2OUT_ED_ERROR_NON_SYN];
 345           return NAT_NEXT_DROP;
 346         }
 347     }
 348
 349   if (PREDICT_FALSE
 350       (nat44_ed_maximum_sessions_exceeded (sm, rx_fib_index, thread_index)))
 351     {
 352       if (!nat_lru_free_one (sm, thread_index, now))
 353         {
 354           b->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 355           nat_ipfix_logging_max_sessions (thread_index,
 356                                           sm->max_translations_per_thread);
 357           nat_elog_notice ("maximum sessions exceeded");
 358           return NAT_NEXT_DROP;
 359         }
 360     }
 361
 362   ip4_address_t sm_addr;
 363   u16 sm_port;
 364   u32 sm_fib_index;
 365   /* First try to match static mapping by local address and port */
 366   if (snat_static_mapping_match
 367       (sm, l_addr, l_port, rx_fib_index, nat_proto, &sm_addr, &sm_port,
 368        &sm_fib_index, 0, 0, 0, &lb, 0, &identity_nat))
 369     {
 370       s = nat_ed_session_alloc (sm, thread_index, now, proto);
 371       if (!s)
 372         {
 373           nat_elog_warn ("create NAT session failed");
 374           b->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_USER_SESS_EXCEEDED];
 375           return NAT_NEXT_DROP;
 376         }
 377       s->in2out.addr = l_addr;
 378       s->in2out.port = l_port;
 379       s->nat_proto = nat_proto;
 380       s->in2out.fib_index = rx_fib_index;
 381       s->out2in.fib_index = sm->outside_fib_index;
 382
 383       switch (vec_len (sm->outside_fibs))
 384         {
 385         case 0:
 386           s->out2in.fib_index = sm->outside_fib_index;
 387           break;
 388         case 1:
 389           s->out2in.fib_index = sm->outside_fibs[0].fib_index;
 390           break;
 391         default:
 392           s->out2in.fib_index = nat_outside_fib_index_lookup (sm, r_addr);
 393           break;
 394         }
 395
 396       /* Try to create dynamic translation */
 397       outside_port = l_port;    // suggest using local port to allocation function
 398       if (nat_ed_alloc_addr_and_port (sm, rx_fib_index, nat_proto,
 399                                       thread_index, r_addr, r_port, proto,
 400                                       sm->port_per_thread,
 401                                       tsm->snat_thread_index, s,
 402                                       &outside_addr,
 403                                       &outside_port, &out2in_ed_kv))
 404         {
 405           nat_elog_notice ("addresses exhausted");
 406           b->error = node->errors[NAT_IN2OUT_ED_ERROR_OUT_OF_PORTS];
 407           nat_ed_session_delete (sm, s, thread_index, 1);
 408           return NAT_NEXT_DROP;
 409         }
 410       s->out2in.addr = outside_addr;
 411       s->out2in.port = outside_port;
 412     }
 413   else
 414     {
 415       if (PREDICT_FALSE (identity_nat))
 416         {
 417           *sessionp = NULL;
 418           return next;
 419         }
 420       s = nat_ed_session_alloc (sm, thread_index, now, proto);
 421       if (!s)
 422         {
 423           nat_elog_warn ("create NAT session failed");
 424           b->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_USER_SESS_EXCEEDED];
 425           return NAT_NEXT_DROP;
 426         }
 427       s->out2in.addr = sm_addr;
 428       s->out2in.port = sm_port;
 429       s->in2out.addr = l_addr;
 430       s->in2out.port = l_port;
 431       s->nat_proto = nat_proto;
 432       s->in2out.fib_index = rx_fib_index;
 433       s->out2in.fib_index = sm->outside_fib_index;
 434       switch (vec_len (sm->outside_fibs))
 435         {
 436         case 0:
 437           s->out2in.fib_index = sm->outside_fib_index;
 438           break;
 439         case 1:
 440           s->out2in.fib_index = sm->outside_fibs[0].fib_index;
 441           break;
 442         default:
 443           s->out2in.fib_index = nat_outside_fib_index_lookup (sm, r_addr);
 444           break;
 445         }
 446
 447       s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 448
 449       init_ed_kv (&out2in_ed_kv, sm_addr, sm_port, r_addr, r_port,
 450                   s->out2in.fib_index, proto, thread_index,
 451                   s - tsm->sessions);
 452       if (clib_bihash_add_or_overwrite_stale_16_8
 453           (&sm->out2in_ed, &out2in_ed_kv, nat44_o2i_ed_is_idle_session_cb,
 454            &ctx))
 455         nat_elog_notice ("out2in-ed key add failed");
 456     }
 457
 458   if (lb)
 459     s->flags |= SNAT_SESSION_FLAG_LOAD_BALANCING;
 460   s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 461   s->ext_host_addr = r_addr;
 462   s->ext_host_port = r_port;
 463
 464   clib_bihash_kv_16_8_t in2out_ed_kv;
 465   init_ed_kv (&in2out_ed_kv, l_addr, l_port, r_addr, r_port, rx_fib_index,
 466               proto, thread_index, s - tsm->sessions);
 467   ctx.now = now;
 468   ctx.thread_index = thread_index;
 469   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->in2out_ed, &in2out_ed_kv,
 470                                                nat44_i2o_ed_is_idle_session_cb,
 471                                                &ctx))
 472     nat_elog_notice ("in2out-ed key add failed");
 473
 474   *sessionp = s;
 475
 476   /* log NAT event */
 477   snat_ipfix_logging_nat44_ses_create (thread_index,
 478                                        s->in2out.addr.as_u32,
 479                                        s->out2in.addr.as_u32,
 480                                        s->nat_proto,
 481                                        s->in2out.port,
 482                                        s->out2in.port, s->in2out.fib_index);
 483
 484   nat_syslog_nat44_sadd (s->user_index, s->in2out.fib_index,
 485                          &s->in2out.addr, s->in2out.port,
 486                          &s->ext_host_nat_addr, s->ext_host_nat_port,
 487                          &s->out2in.addr, s->out2in.port,
 488                          &s->ext_host_addr, s->ext_host_port, s->nat_proto,
 489                          0);
 490
 491   nat_ha_sadd (&s->in2out.addr, s->in2out.port, &s->out2in.addr,
 492                s->out2in.port, &s->ext_host_addr, s->ext_host_port,
 493                &s->ext_host_nat_addr, s->ext_host_nat_port,
 494                s->nat_proto, s->in2out.fib_index, s->flags, thread_index, 0);
 495
 496   return next;
 497 }
 498
 499 static_always_inline int
 500 nat44_ed_not_translate (snat_main_t * sm, vlib_node_runtime_t * node,
 501                         u32 sw_if_index, ip4_header_t * ip, u32 proto,
 502                         u32 rx_fib_index, u32 thread_index)
 503 {
 504   udp_header_t *udp = ip4_next_header (ip);
 505   clib_bihash_kv_16_8_t kv, value;
 506
 507   init_ed_k (&kv, ip->dst_address, udp->dst_port, ip->src_address,
 508              udp->src_port, sm->outside_fib_index, ip->protocol);
 509
 510   /* NAT packet aimed at external address if has active sessions */
 511   if (clib_bihash_search_16_8 (&sm->out2in_ed, &kv, &value))
 512     {
 513       /* or is static mappings */
 514       ip4_address_t dummy_addr;
 515       u16 dummy_port;
 516       u32 dummy_fib_index;
 517       if (!snat_static_mapping_match
 518           (sm, ip->dst_address, udp->dst_port, sm->outside_fib_index, proto,
 519            &dummy_addr, &dummy_port, &dummy_fib_index, 1, 0, 0, 0, 0, 0))
 520         return 0;
 521     }
 522   else
 523     return 0;
 524
 525   if (sm->forwarding_enabled)
 526     return 1;
 527
 528   return snat_not_translate_fast (sm, node, sw_if_index, ip, proto,
 529                                   rx_fib_index);
 530 }
 531
 532 static_always_inline int
 533 nat_not_translate_output_feature_fwd (snat_main_t * sm, ip4_header_t * ip,
 534                                       u32 thread_index, f64 now,
 535                                       vlib_main_t * vm, vlib_buffer_t * b)
 536 {
 537   clib_bihash_kv_16_8_t kv, value;
 538   snat_session_t *s = 0;
 539   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 540
 541   if (!sm->forwarding_enabled)
 542     return 0;
 543
 544   if (ip->protocol == IP_PROTOCOL_ICMP)
 545     {
 546       if (get_icmp_i2o_ed_key (b, ip, 0, ~0, ~0, 0, 0, 0, &kv))
 547         return 0;
 548     }
 549   else if (ip->protocol == IP_PROTOCOL_UDP || ip->protocol == IP_PROTOCOL_TCP)
 550     {
 551       init_ed_k (&kv, ip->src_address, vnet_buffer (b)->ip.reass.l4_src_port,
 552                  ip->dst_address, vnet_buffer (b)->ip.reass.l4_dst_port, 0,
 553                  ip->protocol);
 554     }
 555   else
 556     {
 557       init_ed_k (&kv, ip->src_address, 0, ip->dst_address, 0, 0,
 558                  ip->protocol);
 559     }
 560
 561   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 562     {
 563       ASSERT (thread_index == ed_value_get_thread_index (&value));
 564       s =
 565         pool_elt_at_index (tsm->sessions,
 566                            ed_value_get_session_index (&value));
 567       if (is_fwd_bypass_session (s))
 568         {
 569           if (ip->protocol == IP_PROTOCOL_TCP)
 570             {
 571               if (nat44_set_tcp_session_state_i2o
 572                   (sm, now, s, b, thread_index))
 573                 return 1;
 574             }
 575           /* Accounting */
 576           nat44_session_update_counters (s, now,
 577                                          vlib_buffer_length_in_chain (vm, b),
 578                                          thread_index);
 579           /* Per-user LRU list maintenance */
 580           nat44_session_update_lru (sm, s, thread_index);
 581           return 1;
 582         }
 583       else
 584         return 0;
 585     }
 586
 587   return 0;
 588 }
 589
 590 static_always_inline int
 591 nat44_ed_not_translate_output_feature (snat_main_t * sm, ip4_header_t * ip,
 592                                        u16 src_port, u16 dst_port,
 593                                        u32 thread_index, u32 rx_sw_if_index,
 594                                        u32 tx_sw_if_index)
 595 {
 596   clib_bihash_kv_16_8_t kv, value;
 597   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 598   snat_interface_t *i;
 599   snat_session_t *s;
 600   u32 rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (rx_sw_if_index);
 601   u32 tx_fib_index = ip4_fib_table_get_index_for_sw_if_index (tx_sw_if_index);
 602
 603   /* src NAT check */
 604   init_ed_k (&kv, ip->src_address, src_port, ip->dst_address, dst_port,
 605              tx_fib_index, ip->protocol);
 606   if (!clib_bihash_search_16_8 (&sm->out2in_ed, &kv, &value))
 607     {
 608       ASSERT (thread_index == ed_value_get_thread_index (&value));
 609       s =
 610         pool_elt_at_index (tsm->sessions,
 611                            ed_value_get_session_index (&value));
 612       if (nat44_is_ses_closed (s))
 613         {
 614           nat_free_session_data (sm, s, thread_index, 0);
 615           nat_ed_session_delete (sm, s, thread_index, 1);
 616         }
 617       else
 618         s->flags |= SNAT_SESSION_FLAG_OUTPUT_FEATURE;
 619       return 1;
 620     }
 621
 622   /* dst NAT check */
 623   init_ed_k (&kv, ip->dst_address, dst_port, ip->src_address, src_port,
 624              rx_fib_index, ip->protocol);
 625   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 626     {
 627       ASSERT (thread_index == ed_value_get_thread_index (&value));
 628       s =
 629         pool_elt_at_index (tsm->sessions,
 630                            ed_value_get_session_index (&value));
 631       if (is_fwd_bypass_session (s))
 632         return 0;
 633
 634       /* hairpinning */
 635       /* *INDENT-OFF* */
 636       pool_foreach (i, sm->output_feature_interfaces,
 637       ({
 638         if ((nat_interface_is_inside (i)) && (rx_sw_if_index == i->sw_if_index))
 639            return 0;
 640       }));
 641       /* *INDENT-ON* */
 642       return 1;
 643     }
 644
 645   return 0;
 646 }
 647
 648 #ifndef CLIB_MARCH_VARIANT
 649 u32
 650 icmp_match_in2out_ed (snat_main_t * sm, vlib_node_runtime_t * node,
 651                       u32 thread_index, vlib_buffer_t * b,
 652                       ip4_header_t * ip, ip4_address_t * addr,
 653                       u16 * port, u32 * fib_index, nat_protocol_t * proto,
 654                       void *d, void *e, u8 * dont_translate)
 655 {
 656   u32 sw_if_index;
 657   u32 rx_fib_index;
 658   clib_bihash_kv_16_8_t kv, value;
 659   u32 next = ~0;
 660   int err;
 661   snat_session_t *s = NULL;
 662   u16 l_port = 0, r_port = 0;   // initialize to workaround gcc warning
 663   vlib_main_t *vm = vlib_get_main ();
 664   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 665   *dont_translate = 0;
 666
 667   sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
 668   rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 669
 670   err =
 671     get_icmp_i2o_ed_key (b, ip, rx_fib_index, ~0, ~0, proto, &l_port,
 672                          &r_port, &kv);
 673   if (err != 0)
 674     {
 675       b->error = node->errors[err];
 676       next = NAT_NEXT_DROP;
 677       goto out;
 678     }
 679
 680   if (clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 681     {
 682       if (vnet_buffer (b)->sw_if_index[VLIB_TX] != ~0)
 683         {
 684           if (PREDICT_FALSE
 685               (nat44_ed_not_translate_output_feature
 686                (sm, ip, l_port, r_port, thread_index,
 687                 sw_if_index, vnet_buffer (b)->sw_if_index[VLIB_TX])))
 688             {
 689               *dont_translate = 1;
 690               goto out;
 691             }
 692         }
 693       else
 694         {
 695           if (PREDICT_FALSE (nat44_ed_not_translate (sm, node, sw_if_index,
 696                                                      ip, NAT_PROTOCOL_ICMP,
 697                                                      rx_fib_index,
 698                                                      thread_index)))
 699             {
 700               *dont_translate = 1;
 701               goto out;
 702             }
 703         }
 704
 705       if (PREDICT_FALSE
 706           (icmp_type_is_error_message
 707            (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags)))
 708         {
 709           b->error = node->errors[NAT_IN2OUT_ED_ERROR_BAD_ICMP_TYPE];
 710           next = NAT_NEXT_DROP;
 711           goto out;
 712         }
 713
 714       next =
 715         slow_path_ed (sm, b, ip->src_address, ip->dst_address, l_port, r_port,
 716                       ip->protocol, rx_fib_index, &s, node, next,
 717                       thread_index, vlib_time_now (vm));
 718
 719       if (PREDICT_FALSE (next == NAT_NEXT_DROP))
 720         goto out;
 721
 722       if (!s)
 723         {
 724           *dont_translate = 1;
 725           goto out;
 726         }
 727     }
 728   else
 729     {
 730       if (PREDICT_FALSE
 731           (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 732            ICMP4_echo_request
 733            && vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 734            ICMP4_echo_reply
 735            && !icmp_type_is_error_message (vnet_buffer (b)->ip.
 736                                            reass.icmp_type_or_tcp_flags)))
 737         {
 738           b->error = node->errors[NAT_IN2OUT_ED_ERROR_BAD_ICMP_TYPE];
 739           next = NAT_NEXT_DROP;
 740           goto out;
 741         }
 742
 743       ASSERT (thread_index == ed_value_get_thread_index (&value));
 744       s =
 745         pool_elt_at_index (tsm->sessions,
 746                            ed_value_get_session_index (&value));
 747     }
 748 out:
 749   if (s)
 750     {
 751       *addr = s->out2in.addr;
 752       *port = s->out2in.port;
 753       *fib_index = s->out2in.fib_index;
 754     }
 755   if (d)
 756     {
 757       *(snat_session_t **) d = s;
 758     }
 759   return next;
 760 }
 761 #endif
 762
 763 static snat_session_t *
 764 nat44_ed_in2out_unknown_proto (snat_main_t * sm,
 765                                vlib_buffer_t * b,
 766                                ip4_header_t * ip,
 767                                u32 rx_fib_index,
 768                                u32 thread_index,
 769                                f64 now,
 770                                vlib_main_t * vm, vlib_node_runtime_t * node)
 771 {
 772   clib_bihash_kv_8_8_t kv, value;
 773   clib_bihash_kv_16_8_t s_kv, s_value;
 774   snat_static_mapping_t *m;
 775   u32 old_addr, new_addr = 0;
 776   ip_csum_t sum;
 777   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 778   snat_session_t *s;
 779   u32 outside_fib_index = sm->outside_fib_index;
 780   int i;
 781   u8 is_sm = 0;
 782
 783   switch (vec_len (sm->outside_fibs))
 784     {
 785     case 0:
 786       outside_fib_index = sm->outside_fib_index;
 787       break;
 788     case 1:
 789       outside_fib_index = sm->outside_fibs[0].fib_index;
 790       break;
 791     default:
 792       outside_fib_index = nat_outside_fib_index_lookup (sm, ip->dst_address);
 793       break;
 794     }
 795   old_addr = ip->src_address.as_u32;
 796
 797   init_ed_k (&s_kv, ip->src_address, 0, ip->dst_address, 0, rx_fib_index,
 798              ip->protocol);
 799
 800   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &s_kv, &s_value))
 801     {
 802       ASSERT (thread_index == ed_value_get_thread_index (&s_value));
 803       s =
 804         pool_elt_at_index (tsm->sessions,
 805                            ed_value_get_session_index (&s_value));
 806       new_addr = ip->src_address.as_u32 = s->out2in.addr.as_u32;
 807     }
 808   else
 809     {
 810       if (PREDICT_FALSE
 811           (nat44_ed_maximum_sessions_exceeded
 812            (sm, rx_fib_index, thread_index)))
 813         {
 814           b->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 815           nat_ipfix_logging_max_sessions (thread_index,
 816                                           sm->max_translations_per_thread);
 817           nat_elog_notice ("maximum sessions exceeded");
 818           return 0;
 819         }
 820
 821       init_nat_k (&kv, ip->src_address, 0, rx_fib_index, 0);
 822
 823       /* Try to find static mapping first */
 824       if (!clib_bihash_search_8_8 (&sm->static_mapping_by_local, &kv, &value))
 825         {
 826           m = pool_elt_at_index (sm->static_mappings, value.value);
 827           new_addr = ip->src_address.as_u32 = m->external_addr.as_u32;
 828           is_sm = 1;
 829           goto create_ses;
 830         }
 831       else
 832         {
 833           /* *INDENT-OFF* */
 834           pool_foreach (s, tsm->sessions, {
 835             if (s->ext_host_addr.as_u32 == ip->dst_address.as_u32)
 836               {
 837                 new_addr = ip->src_address.as_u32 = s->out2in.addr.as_u32;
 838
 839                 init_ed_k(&s_kv, s->out2in.addr, 0, ip->dst_address, 0, outside_fib_index, ip->protocol);
 840                 if (clib_bihash_search_16_8 (&sm->out2in_ed, &s_kv, &s_value))
 841                   goto create_ses;
 842
 843                 break;
 844               }
 845           });
 846           /* *INDENT-ON* */
 847
 848           for (i = 0; i < vec_len (sm->addresses); i++)
 849             {
 850               init_ed_k (&s_kv, sm->addresses[i].addr, 0, ip->dst_address, 0,
 851                          outside_fib_index, ip->protocol);
 852               if (clib_bihash_search_16_8 (&sm->out2in_ed, &s_kv, &s_value))
 853                 {
 854                   new_addr = ip->src_address.as_u32 =
 855                     sm->addresses[i].addr.as_u32;
 856                   goto create_ses;
 857                 }
 858             }
 859           return 0;
 860         }
 861
 862     create_ses:
 863       s = nat_ed_session_alloc (sm, thread_index, now, ip->protocol);
 864       if (!s)
 865         {
 866           b->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_USER_SESS_EXCEEDED];
 867           nat_elog_warn ("create NAT session failed");
 868           return 0;
 869         }
 870
 871       s->ext_host_addr.as_u32 = ip->dst_address.as_u32;
 872       s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 873       s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 874       s->out2in.addr.as_u32 = new_addr;
 875       s->out2in.fib_index = outside_fib_index;
 876       s->in2out.addr.as_u32 = old_addr;
 877       s->in2out.fib_index = rx_fib_index;
 878       s->in2out.port = s->out2in.port = ip->protocol;
 879       if (is_sm)
 880         s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 881
 882       /* Add to lookup tables */
 883       init_ed_kv (&s_kv, s->in2out.addr, 0, ip->dst_address, 0, rx_fib_index,
 884                   ip->protocol, thread_index, s - tsm->sessions);
 885       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &s_kv, 1))
 886         nat_elog_notice ("in2out key add failed");
 887
 888       init_ed_kv (&s_kv, s->out2in.addr, 0, ip->dst_address, 0,
 889                   outside_fib_index, ip->protocol, thread_index,
 890                   s - tsm->sessions);
 891       if (clib_bihash_add_del_16_8 (&sm->out2in_ed, &s_kv, 1))
 892         nat_elog_notice ("out2in key add failed");
 893     }
 894
 895   /* Update IP checksum */
 896   sum = ip->checksum;
 897   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, src_address);
 898   ip->checksum = ip_csum_fold (sum);
 899
 900   /* Accounting */
 901   nat44_session_update_counters (s, now, vlib_buffer_length_in_chain (vm, b),
 902                                  thread_index);
 903   /* Per-user LRU list maintenance */
 904   nat44_session_update_lru (sm, s, thread_index);
 905
 906   /* Hairpinning */
 907   if (vnet_buffer (b)->sw_if_index[VLIB_TX] == ~0)
 908     nat44_ed_hairpinning_unknown_proto (sm, b, ip);
 909
 910   if (vnet_buffer (b)->sw_if_index[VLIB_TX] == ~0)
 911     vnet_buffer (b)->sw_if_index[VLIB_TX] = outside_fib_index;
 912
 913   return s;
 914 }
 915
 916 static inline uword
 917 nat44_ed_in2out_fast_path_node_fn_inline (vlib_main_t * vm,
 918                                           vlib_node_runtime_t * node,
 919                                           vlib_frame_t * frame,
 920                                           int is_output_feature)
 921 {
 922   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
 923   nat_next_t next_index;
 924   snat_main_t *sm = &snat_main;
 925   f64 now = vlib_time_now (vm);
 926   u32 thread_index = vm->thread_index;
 927   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 928   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 929     0, def_slow;
 930
 931   def_slow = is_output_feature ? NAT_NEXT_IN2OUT_ED_OUTPUT_SLOW_PATH :
 932     NAT_NEXT_IN2OUT_ED_SLOW_PATH;
 933
 934   stats_node_index = sm->ed_in2out_node_index;
 935
 936   from = vlib_frame_vector_args (frame);
 937   n_left_from = frame->n_vectors;
 938   next_index = node->cached_next_index;
 939
 940   while (n_left_from > 0)
 941     {
 942       u32 n_left_to_next;
 943
 944       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 945
 946       while (n_left_from > 0 && n_left_to_next > 0)
 947         {
 948           u32 bi0;
 949           vlib_buffer_t *b0;
 950           u32 next0, sw_if_index0, rx_fib_index0, iph_offset0 = 0, proto0,
 951             new_addr0, old_addr0;
 952           u16 old_port0, new_port0;
 953           ip4_header_t *ip0;
 954           udp_header_t *udp0;
 955           tcp_header_t *tcp0;
 956           snat_session_t *s0 = 0;
 957           clib_bihash_kv_16_8_t kv0, value0;
 958           ip_csum_t sum0;
 959
 960           /* speculatively enqueue b0 to the current next frame */
 961           bi0 = from[0];
 962           to_next[0] = bi0;
 963           from += 1;
 964           to_next += 1;
 965           n_left_from -= 1;
 966           n_left_to_next -= 1;
 967
 968           b0 = vlib_get_buffer (vm, bi0);
 969
 970           if (is_output_feature)
 971             {
 972               vnet_feature_next (&vnet_buffer2 (b0)->nat.arc_next, b0);
 973               iph_offset0 = vnet_buffer (b0)->ip.reass.save_rewrite_length;
 974             }
 975
 976           next0 = vnet_buffer2 (b0)->nat.arc_next;
 977
 978           ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
 979                                   iph_offset0);
 980
 981           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 982           rx_fib_index0 =
 983             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 984                                                  sw_if_index0);
 985
 986           if (PREDICT_FALSE (ip0->ttl == 1))
 987             {
 988               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 989               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 990                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 991                                            0);
 992               next0 = NAT_NEXT_ICMP_ERROR;
 993               goto trace0;
 994             }
 995
 996           udp0 = ip4_next_header (ip0);
 997           tcp0 = (tcp_header_t *) udp0;
 998           proto0 = ip_proto_to_nat_proto (ip0->protocol);
 999
1000           if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
1001             {
1002               next0 = def_slow;
1003               goto trace0;
1004             }
1005
1006           if (is_output_feature)
1007             {
1008               if (PREDICT_FALSE (nat_not_translate_output_feature_fwd
1009                                  (sm, ip0, thread_index, now, vm, b0)))
1010                 goto trace0;
1011             }
1012
1013           if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
1014             {
1015               next0 = def_slow;
1016               goto trace0;
1017             }
1018
1019           init_ed_k (&kv0, ip0->src_address,
1020                      vnet_buffer (b0)->ip.reass.l4_src_port, ip0->dst_address,
1021                      vnet_buffer (b0)->ip.reass.l4_dst_port, rx_fib_index0,
1022                      ip0->protocol);
1023
1024           // lookup for session
1025           if (clib_bihash_search_16_8 (&tsm->in2out_ed, &kv0, &value0))
1026             {
1027               // session does not exist go slow path
1028               next0 = def_slow;
1029               goto trace0;
1030             }
1031           ASSERT (thread_index == ed_value_get_thread_index (&value0));
1032           s0 =
1033             pool_elt_at_index (tsm->sessions,
1034                                ed_value_get_session_index (&value0));
1035
1036           if (s0->tcp_closed_timestamp)
1037             {
1038               if (now >= s0->tcp_closed_timestamp)
1039                 {
1040                   // session is closed, go slow path
1041                   next0 = def_slow;
1042                 }
1043               else
1044                 {
1045                   // session in transitory timeout, drop
1046                   b0->error = node->errors[NAT_IN2OUT_ED_ERROR_TCP_CLOSED];
1047                   next0 = NAT_NEXT_DROP;
1048                 }
1049               goto trace0;
1050             }
1051
1052           // drop if session expired
1053           u64 sess_timeout_time;
1054           sess_timeout_time = s0->last_heard +
1055             (f64) nat44_session_get_timeout (sm, s0);
1056           if (now >= sess_timeout_time)
1057             {
1058               nat_free_session_data (sm, s0, thread_index, 0);
1059               nat_ed_session_delete (sm, s0, thread_index, 1);
1060               // session is closed, go slow path
1061               next0 = def_slow;
1062               goto trace0;
1063             }
1064
1065           b0->flags |= VNET_BUFFER_F_IS_NATED;
1066
1067           if (!is_output_feature)
1068             vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
1069
1070           old_addr0 = ip0->src_address.as_u32;
1071           new_addr0 = ip0->src_address.as_u32 = s0->out2in.addr.as_u32;
1072           sum0 = ip0->checksum;
1073           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1074                                  src_address);
1075           if (PREDICT_FALSE (is_twice_nat_session (s0)))
1076             sum0 = ip_csum_update (sum0, ip0->dst_address.as_u32,
1077                                    s0->ext_host_addr.as_u32, ip4_header_t,
1078                                    dst_address);
1079           ip0->checksum = ip_csum_fold (sum0);
1080
1081           old_port0 = vnet_buffer (b0)->ip.reass.l4_src_port;
1082
1083           if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
1084             {
1085               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1086                 {
1087                   new_port0 = udp0->src_port = s0->out2in.port;
1088                   sum0 = tcp0->checksum;
1089                   sum0 =
1090                     ip_csum_update (sum0, old_addr0, new_addr0,
1091                                     ip4_header_t, dst_address);
1092                   sum0 =
1093                     ip_csum_update (sum0, old_port0, new_port0,
1094                                     ip4_header_t, length);
1095                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
1096                     {
1097                       sum0 =
1098                         ip_csum_update (sum0, ip0->dst_address.as_u32,
1099                                         s0->ext_host_addr.as_u32,
1100                                         ip4_header_t, dst_address);
1101                       sum0 =
1102                         ip_csum_update (sum0,
1103                                         vnet_buffer (b0)->ip.
1104                                         reass.l4_dst_port, s0->ext_host_port,
1105                                         ip4_header_t, length);
1106                       tcp0->dst_port = s0->ext_host_port;
1107                       ip0->dst_address.as_u32 = s0->ext_host_addr.as_u32;
1108                     }
1109                   mss_clamping (sm->mss_clamping, tcp0, &sum0);
1110                   tcp0->checksum = ip_csum_fold (sum0);
1111                 }
1112               tcp_packets++;
1113               if (nat44_set_tcp_session_state_i2o
1114                   (sm, now, s0, b0, thread_index))
1115                 goto trace0;
1116             }
1117           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
1118                    && udp0->checksum)
1119             {
1120               new_port0 = udp0->src_port = s0->out2in.port;
1121               sum0 = udp0->checksum;
1122               sum0 =
1123                 ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1124                                 dst_address);
1125               sum0 =
1126                 ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1127                                 length);
1128               if (PREDICT_FALSE (is_twice_nat_session (s0)))
1129                 {
1130                   sum0 = ip_csum_update (sum0, ip0->dst_address.as_u32,
1131                                          s0->ext_host_addr.as_u32,
1132                                          ip4_header_t, dst_address);
1133                   sum0 =
1134                     ip_csum_update (sum0,
1135                                     vnet_buffer (b0)->ip.reass.l4_dst_port,
1136                                     s0->ext_host_port, ip4_header_t, length);
1137                   udp0->dst_port = s0->ext_host_port;
1138                   ip0->dst_address.as_u32 = s0->ext_host_addr.as_u32;
1139                 }
1140               udp0->checksum = ip_csum_fold (sum0);
1141               udp_packets++;
1142             }
1143           else
1144             {
1145               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1146                 {
1147                   new_port0 = udp0->src_port = s0->out2in.port;
1148                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
1149                     {
1150                       udp0->dst_port = s0->ext_host_port;
1151                       ip0->dst_address.as_u32 = s0->ext_host_addr.as_u32;
1152                     }
1153                   udp_packets++;
1154                 }
1155             }
1156
1157           /* Accounting */
1158           nat44_session_update_counters (s0, now,
1159                                          vlib_buffer_length_in_chain
1160                                          (vm, b0), thread_index);
1161           /* Per-user LRU list maintenance */
1162           nat44_session_update_lru (sm, s0, thread_index);
1163
1164         trace0:
1165           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1166                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1167             {
1168               nat_in2out_ed_trace_t *t =
1169                 vlib_add_trace (vm, node, b0, sizeof (*t));
1170               t->sw_if_index = sw_if_index0;
1171               t->next_index = next0;
1172               t->is_slow_path = 0;
1173
1174               if (s0)
1175                 t->session_index = s0 - tsm->sessions;
1176               else
1177                 t->session_index = ~0;
1178             }
1179
1180           pkts_processed += next0 == vnet_buffer2 (b0)->nat.arc_next;
1181           /* verify speculative enqueue, maybe switch current next frame */
1182           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1183                                            to_next, n_left_to_next,
1184                                            bi0, next0);
1185         }
1186
1187       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1188     }
1189
1190   vlib_node_increment_counter (vm, stats_node_index,
1191                                NAT_IN2OUT_ED_ERROR_IN2OUT_PACKETS,
1192                                pkts_processed);
1193   vlib_node_increment_counter (vm, stats_node_index,
1194                                NAT_IN2OUT_ED_ERROR_TCP_PACKETS, tcp_packets);
1195   vlib_node_increment_counter (vm, stats_node_index,
1196                                NAT_IN2OUT_ED_ERROR_UDP_PACKETS, udp_packets);
1197   vlib_node_increment_counter (vm, stats_node_index,
1198                                NAT_IN2OUT_ED_ERROR_ICMP_PACKETS,
1199                                icmp_packets);
1200   vlib_node_increment_counter (vm, stats_node_index,
1201                                NAT_IN2OUT_ED_ERROR_OTHER_PACKETS,
1202                                other_packets);
1203   return frame->n_vectors;
1204 }
1205
1206 static inline uword
1207 nat44_ed_in2out_slow_path_node_fn_inline (vlib_main_t * vm,
1208                                           vlib_node_runtime_t * node,
1209                                           vlib_frame_t * frame,
1210                                           int is_output_feature)
1211 {
1212   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
1213   nat_next_t next_index;
1214   snat_main_t *sm = &snat_main;
1215   f64 now = vlib_time_now (vm);
1216   u32 thread_index = vm->thread_index;
1217   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
1218   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets = 0;
1219
1220   stats_node_index = sm->ed_in2out_slowpath_node_index;
1221
1222   from = vlib_frame_vector_args (frame);
1223   n_left_from = frame->n_vectors;
1224   next_index = node->cached_next_index;
1225
1226   while (n_left_from > 0)
1227     {
1228       u32 n_left_to_next;
1229
1230       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1231
1232       while (n_left_from > 0 && n_left_to_next > 0)
1233         {
1234           u32 bi0;
1235           vlib_buffer_t *b0;
1236           u32 next0, sw_if_index0, rx_fib_index0, iph_offset0 = 0, proto0,
1237             new_addr0, old_addr0;
1238           u16 old_port0, new_port0;
1239           ip4_header_t *ip0;
1240           udp_header_t *udp0;
1241           tcp_header_t *tcp0;
1242           icmp46_header_t *icmp0;
1243           snat_session_t *s0 = 0;
1244           clib_bihash_kv_16_8_t kv0, value0;
1245           ip_csum_t sum0;
1246
1247           /* speculatively enqueue b0 to the current next frame */
1248           bi0 = from[0];
1249           to_next[0] = bi0;
1250           from += 1;
1251           to_next += 1;
1252           n_left_from -= 1;
1253           n_left_to_next -= 1;
1254
1255           b0 = vlib_get_buffer (vm, bi0);
1256
1257           if (is_output_feature)
1258             iph_offset0 = vnet_buffer (b0)->ip.reass.save_rewrite_length;
1259
1260           next0 = vnet_buffer2 (b0)->nat.arc_next;
1261
1262           ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
1263                                   iph_offset0);
1264
1265           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1266           rx_fib_index0 =
1267             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
1268                                                  sw_if_index0);
1269
1270           if (PREDICT_FALSE (ip0->ttl == 1))
1271             {
1272               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1273               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1274                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1275                                            0);
1276               next0 = NAT_NEXT_ICMP_ERROR;
1277               goto trace0;
1278             }
1279
1280           udp0 = ip4_next_header (ip0);
1281           tcp0 = (tcp_header_t *) udp0;
1282           icmp0 = (icmp46_header_t *) udp0;
1283           proto0 = ip_proto_to_nat_proto (ip0->protocol);
1284
1285           if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
1286             {
1287               s0 = nat44_ed_in2out_unknown_proto (sm, b0, ip0,
1288                                                   rx_fib_index0,
1289                                                   thread_index, now,
1290                                                   vm, node);
1291               if (!s0)
1292                 next0 = NAT_NEXT_DROP;
1293
1294               other_packets++;
1295               goto trace0;
1296             }
1297
1298           if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
1299             {
1300               next0 = icmp_in2out_ed_slow_path
1301                 (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0,
1302                  node, next0, now, thread_index, &s0);
1303               icmp_packets++;
1304               goto trace0;
1305             }
1306
1307           init_ed_k (&kv0, ip0->src_address,
1308                      vnet_buffer (b0)->ip.reass.l4_src_port, ip0->dst_address,
1309                      vnet_buffer (b0)->ip.reass.l4_dst_port, rx_fib_index0,
1310                      ip0->protocol);
1311           if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv0, &value0))
1312             {
1313               ASSERT (thread_index == ed_value_get_thread_index (&value0));
1314               s0 =
1315                 pool_elt_at_index (tsm->sessions,
1316                                    ed_value_get_session_index (&value0));
1317
1318               if (s0->tcp_closed_timestamp && now >= s0->tcp_closed_timestamp)
1319                 {
1320                   nat_free_session_data (sm, s0, thread_index, 0);
1321                   nat_ed_session_delete (sm, s0, thread_index, 1);
1322                   s0 = NULL;
1323                 }
1324             }
1325
1326           if (!s0)
1327             {
1328               if (is_output_feature)
1329                 {
1330                   if (PREDICT_FALSE
1331                       (nat44_ed_not_translate_output_feature
1332                        (sm, ip0, vnet_buffer (b0)->ip.reass.l4_src_port,
1333                         vnet_buffer (b0)->ip.reass.l4_dst_port, thread_index,
1334                         sw_if_index0,
1335                         vnet_buffer (b0)->sw_if_index[VLIB_TX])))
1336                     goto trace0;
1337
1338                   /*
1339                    * Send DHCP packets to the ipv4 stack, or we won't
1340                    * be able to use dhcp client on the outside interface
1341                    */
1342                   if (PREDICT_FALSE
1343                       (proto0 == NAT_PROTOCOL_UDP
1344                        && (vnet_buffer (b0)->ip.reass.l4_dst_port ==
1345                            clib_host_to_net_u16 (UDP_DST_PORT_dhcp_to_server))
1346                        && ip0->dst_address.as_u32 == 0xffffffff))
1347                     goto trace0;
1348                 }
1349               else
1350                 {
1351                   if (PREDICT_FALSE
1352                       (nat44_ed_not_translate
1353                        (sm, node, sw_if_index0, ip0, proto0, rx_fib_index0,
1354                         thread_index)))
1355                     goto trace0;
1356                 }
1357
1358               next0 =
1359                 slow_path_ed (sm, b0, ip0->src_address, ip0->dst_address,
1360                               vnet_buffer (b0)->ip.reass.l4_src_port,
1361                               vnet_buffer (b0)->ip.reass.l4_dst_port,
1362                               ip0->protocol, rx_fib_index0, &s0, node, next0,
1363                               thread_index, now);
1364
1365               if (PREDICT_FALSE (next0 == NAT_NEXT_DROP))
1366                 goto trace0;
1367
1368               if (PREDICT_FALSE (!s0))
1369                 goto trace0;
1370
1371             }
1372
1373           b0->flags |= VNET_BUFFER_F_IS_NATED;
1374
1375           if (!is_output_feature)
1376             vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
1377
1378           old_addr0 = ip0->src_address.as_u32;
1379           new_addr0 = ip0->src_address.as_u32 = s0->out2in.addr.as_u32;
1380           sum0 = ip0->checksum;
1381           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1382                                  src_address);
1383           if (PREDICT_FALSE (is_twice_nat_session (s0)))
1384             sum0 = ip_csum_update (sum0, ip0->dst_address.as_u32,
1385                                    s0->ext_host_addr.as_u32, ip4_header_t,
1386                                    dst_address);
1387           ip0->checksum = ip_csum_fold (sum0);
1388
1389           old_port0 = vnet_buffer (b0)->ip.reass.l4_src_port;
1390
1391           if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
1392             {
1393               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1394                 {
1395                   new_port0 = udp0->src_port = s0->out2in.port;
1396                   sum0 = tcp0->checksum;
1397                   sum0 =
1398                     ip_csum_update (sum0, old_addr0, new_addr0,
1399                                     ip4_header_t, dst_address);
1400                   sum0 =
1401                     ip_csum_update (sum0, old_port0, new_port0,
1402                                     ip4_header_t, length);
1403                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
1404                     {
1405                       sum0 =
1406                         ip_csum_update (sum0, ip0->dst_address.as_u32,
1407                                         s0->ext_host_addr.as_u32,
1408                                         ip4_header_t, dst_address);
1409                       sum0 =
1410                         ip_csum_update (sum0,
1411                                         vnet_buffer (b0)->ip.
1412                                         reass.l4_dst_port, s0->ext_host_port,
1413                                         ip4_header_t, length);
1414                       tcp0->dst_port = s0->ext_host_port;
1415                       ip0->dst_address.as_u32 = s0->ext_host_addr.as_u32;
1416                     }
1417                   mss_clamping (sm->mss_clamping, tcp0, &sum0);
1418                   tcp0->checksum = ip_csum_fold (sum0);
1419                 }
1420               tcp_packets++;
1421               if (nat44_set_tcp_session_state_i2o
1422                   (sm, now, s0, b0, thread_index))
1423                 goto trace0;
1424             }
1425           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
1426                    && udp0->checksum)
1427             {
1428               new_port0 = udp0->src_port = s0->out2in.port;
1429               sum0 = udp0->checksum;
1430               sum0 =
1431                 ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1432                                 dst_address);
1433               sum0 =
1434                 ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1435                                 length);
1436               if (PREDICT_FALSE (is_twice_nat_session (s0)))
1437                 {
1438                   sum0 = ip_csum_update (sum0, ip0->dst_address.as_u32,
1439                                          s0->ext_host_addr.as_u32,
1440                                          ip4_header_t, dst_address);
1441                   sum0 =
1442                     ip_csum_update (sum0,
1443                                     vnet_buffer (b0)->ip.reass.l4_dst_port,
1444                                     s0->ext_host_port, ip4_header_t, length);
1445                   udp0->dst_port = s0->ext_host_port;
1446                   ip0->dst_address.as_u32 = s0->ext_host_addr.as_u32;
1447                 }
1448               udp0->checksum = ip_csum_fold (sum0);
1449               udp_packets++;
1450             }
1451           else
1452             {
1453               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1454                 {
1455                   new_port0 = udp0->src_port = s0->out2in.port;
1456                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
1457                     {
1458                       udp0->dst_port = s0->ext_host_port;
1459                       ip0->dst_address.as_u32 = s0->ext_host_addr.as_u32;
1460                     }
1461                   udp_packets++;
1462                 }
1463             }
1464
1465           /* Accounting */
1466           nat44_session_update_counters (s0, now,
1467                                          vlib_buffer_length_in_chain
1468                                          (vm, b0), thread_index);
1469           /* Per-user LRU list maintenance */
1470           nat44_session_update_lru (sm, s0, thread_index);
1471
1472         trace0:
1473           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1474                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1475             {
1476               nat_in2out_ed_trace_t *t =
1477                 vlib_add_trace (vm, node, b0, sizeof (*t));
1478               t->sw_if_index = sw_if_index0;
1479               t->next_index = next0;
1480               t->is_slow_path = 1;
1481
1482               if (s0)
1483                 t->session_index = s0 - tsm->sessions;
1484               else
1485                 t->session_index = ~0;
1486             }
1487
1488           pkts_processed += next0 == vnet_buffer2 (b0)->nat.arc_next;
1489
1490           /* verify speculative enqueue, maybe switch current next frame */
1491           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1492                                            to_next, n_left_to_next,
1493                                            bi0, next0);
1494         }
1495
1496       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1497     }
1498
1499   vlib_node_increment_counter (vm, stats_node_index,
1500                                NAT_IN2OUT_ED_ERROR_IN2OUT_PACKETS,
1501                                pkts_processed);
1502   vlib_node_increment_counter (vm, stats_node_index,
1503                                NAT_IN2OUT_ED_ERROR_TCP_PACKETS, tcp_packets);
1504   vlib_node_increment_counter (vm, stats_node_index,
1505                                NAT_IN2OUT_ED_ERROR_UDP_PACKETS, udp_packets);
1506   vlib_node_increment_counter (vm, stats_node_index,
1507                                NAT_IN2OUT_ED_ERROR_ICMP_PACKETS,
1508                                icmp_packets);
1509   vlib_node_increment_counter (vm, stats_node_index,
1510                                NAT_IN2OUT_ED_ERROR_OTHER_PACKETS,
1511                                other_packets);
1512   return frame->n_vectors;
1513 }
1514
1515 VLIB_NODE_FN (nat44_ed_in2out_node) (vlib_main_t * vm,
1516                                      vlib_node_runtime_t * node,
1517                                      vlib_frame_t * frame)
1518 {
1519   return nat44_ed_in2out_fast_path_node_fn_inline (vm, node, frame, 0);
1520 }
1521
1522 /* *INDENT-OFF* */
1523 VLIB_REGISTER_NODE (nat44_ed_in2out_node) = {
1524   .name = "nat44-ed-in2out",
1525   .vector_size = sizeof (u32),
1526   .sibling_of = "nat-default",
1527   .format_trace = format_nat_in2out_ed_trace,
1528   .type = VLIB_NODE_TYPE_INTERNAL,
1529   .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
1530   .error_strings = nat_in2out_ed_error_strings,
1531   .runtime_data_bytes = sizeof (snat_runtime_t),
1532 };
1533 /* *INDENT-ON* */
1534
1535 VLIB_NODE_FN (nat44_ed_in2out_output_node) (vlib_main_t * vm,
1536                                             vlib_node_runtime_t * node,
1537                                             vlib_frame_t * frame)
1538 {
1539   return nat44_ed_in2out_fast_path_node_fn_inline (vm, node, frame, 1);
1540 }
1541
1542 /* *INDENT-OFF* */
1543 VLIB_REGISTER_NODE (nat44_ed_in2out_output_node) = {
1544   .name = "nat44-ed-in2out-output",
1545   .vector_size = sizeof (u32),
1546   .sibling_of = "nat-default",
1547   .format_trace = format_nat_in2out_ed_trace,
1548   .type = VLIB_NODE_TYPE_INTERNAL,
1549   .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
1550   .error_strings = nat_in2out_ed_error_strings,
1551   .runtime_data_bytes = sizeof (snat_runtime_t),
1552 };
1553 /* *INDENT-ON* */
1554
1555 VLIB_NODE_FN (nat44_ed_in2out_slowpath_node) (vlib_main_t * vm,
1556                                               vlib_node_runtime_t *
1557                                               node, vlib_frame_t * frame)
1558 {
1559   return nat44_ed_in2out_slow_path_node_fn_inline (vm, node, frame, 0);
1560 }
1561
1562 /* *INDENT-OFF* */
1563 VLIB_REGISTER_NODE (nat44_ed_in2out_slowpath_node) = {
1564   .name = "nat44-ed-in2out-slowpath",
1565   .vector_size = sizeof (u32),
1566   .sibling_of = "nat-default",
1567   .format_trace = format_nat_in2out_ed_trace,
1568   .type = VLIB_NODE_TYPE_INTERNAL,
1569   .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
1570   .error_strings = nat_in2out_ed_error_strings,
1571   .runtime_data_bytes = sizeof (snat_runtime_t),
1572 };
1573 /* *INDENT-ON* */
1574
1575 VLIB_NODE_FN (nat44_ed_in2out_output_slowpath_node) (vlib_main_t * vm,
1576                                                      vlib_node_runtime_t
1577                                                      * node,
1578                                                      vlib_frame_t * frame)
1579 {
1580   return nat44_ed_in2out_slow_path_node_fn_inline (vm, node, frame, 1);
1581 }
1582
1583 /* *INDENT-OFF* */
1584 VLIB_REGISTER_NODE (nat44_ed_in2out_output_slowpath_node) = {
1585   .name = "nat44-ed-in2out-output-slowpath",
1586   .vector_size = sizeof (u32),
1587   .sibling_of = "nat-default",
1588   .format_trace = format_nat_in2out_ed_trace,
1589   .type = VLIB_NODE_TYPE_INTERNAL,
1590   .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
1591   .error_strings = nat_in2out_ed_error_strings,
1592   .runtime_data_bytes = sizeof (snat_runtime_t),
1593 };
1594 /* *INDENT-ON* */
1595
1596 static u8 *
1597 format_nat_pre_trace (u8 * s, va_list * args)
1598 {
1599   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1600   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1601   nat_pre_trace_t *t = va_arg (*args, nat_pre_trace_t *);
1602   return format (s, "in2out next_index %d arc_next_index %d", t->next_index,
1603                  t->arc_next_index);
1604 }
1605
1606 VLIB_NODE_FN (nat_pre_in2out_node)
1607   (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
1608 {
1609   return nat_pre_node_fn_inline (vm, node, frame,
1610                                  NAT_NEXT_IN2OUT_ED_FAST_PATH);
1611 }
1612
1613 /* *INDENT-OFF* */
1614 VLIB_REGISTER_NODE (nat_pre_in2out_node) = {
1615   .name = "nat-pre-in2out",
1616   .vector_size = sizeof (u32),
1617   .sibling_of = "nat-default",
1618   .format_trace = format_nat_pre_trace,
1619   .type = VLIB_NODE_TYPE_INTERNAL,
1620   .n_errors = 0,
1621 };
1622 /* *INDENT-ON* */
1623
1624 /*
1625  * fd.io coding-style-patch-verification: ON
1626  *
1627  * Local Variables:
1628  * eval: (c-set-style "gnu")
1629  * End:
1630  */