src/plugins/nat/out2in_ed.c

   1 /*
   2  * Copyright (c) 2018 Cisco and/or its affiliates.
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15 /**
  16  * @file
  17  * @brief NAT44 endpoint-dependent outside to inside network translation
  18  */
  19
  20 #include <vlib/vlib.h>
  21 #include <vnet/vnet.h>
  22 #include <vnet/pg/pg.h>
  23 #include <vnet/ip/ip.h>
  24 #include <vnet/ethernet/ethernet.h>
  25 #include <vnet/fib/ip4_fib.h>
  26 #include <vnet/udp/udp.h>
  27 #include <vppinfra/error.h>
  28 #include <nat/nat.h>
  29 #include <nat/nat_ipfix_logging.h>
  30 #include <nat/nat_inlines.h>
  31 #include <nat/nat44/inlines.h>
  32 #include <nat/nat_syslog.h>
  33 #include <nat/nat_ha.h>
  34
  35 static char *nat_out2in_ed_error_strings[] = {
  36 #define _(sym,string) string,
  37   foreach_nat_out2in_ed_error
  38 #undef _
  39 };
  40
  41 typedef struct
  42 {
  43   u32 sw_if_index;
  44   u32 next_index;
  45   u32 session_index;
  46   u32 is_slow_path;
  47 } nat44_ed_out2in_trace_t;
  48
  49 static u8 *
  50 format_nat44_ed_out2in_trace (u8 * s, va_list * args)
  51 {
  52   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  53   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  54   nat44_ed_out2in_trace_t *t = va_arg (*args, nat44_ed_out2in_trace_t *);
  55   char *tag;
  56
  57   tag =
  58     t->is_slow_path ? "NAT44_OUT2IN_ED_SLOW_PATH" :
  59     "NAT44_OUT2IN_ED_FAST_PATH";
  60
  61   s = format (s, "%s: sw_if_index %d, next index %d, session %d", tag,
  62               t->sw_if_index, t->next_index, t->session_index);
  63
  64   return s;
  65 }
  66
  67 static inline u32
  68 icmp_out2in_ed_slow_path (snat_main_t * sm, vlib_buffer_t * b0,
  69                           ip4_header_t * ip0, icmp46_header_t * icmp0,
  70                           u32 sw_if_index0, u32 rx_fib_index0,
  71                           vlib_node_runtime_t * node, u32 next0, f64 now,
  72                           u32 thread_index, snat_session_t ** p_s0)
  73 {
  74   next0 = icmp_out2in (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
  75                        next0, thread_index, p_s0, 0);
  76   snat_session_t *s0 = *p_s0;
  77   if (PREDICT_TRUE (next0 != NAT_NEXT_DROP && s0))
  78     {
  79       /* Accounting */
  80       nat44_session_update_counters (s0, now,
  81                                      vlib_buffer_length_in_chain
  82                                      (sm->vlib_main, b0), thread_index);
  83       /* Per-user LRU list maintenance */
  84       nat44_session_update_lru (sm, s0, thread_index);
  85     }
  86   return next0;
  87 }
  88
  89 #ifndef CLIB_MARCH_VARIANT
  90 int
  91 nat44_o2i_ed_is_idle_session_cb (clib_bihash_kv_16_8_t * kv, void *arg)
  92 {
  93   snat_main_t *sm = &snat_main;
  94   nat44_is_idle_session_ctx_t *ctx = arg;
  95   snat_session_t *s;
  96   u64 sess_timeout_time;
  97   nat_ed_ses_key_t ed_key;
  98   clib_bihash_kv_16_8_t ed_kv;
  99   int i;
 100   snat_address_t *a;
 101   snat_session_key_t key;
 102   snat_main_per_thread_data_t *tsm = vec_elt_at_index (sm->per_thread_data,
 103                                                        ctx->thread_index);
 104
 105   s = pool_elt_at_index (tsm->sessions, kv->value);
 106   sess_timeout_time = s->last_heard + (f64) nat44_session_get_timeout (sm, s);
 107   if (ctx->now >= sess_timeout_time)
 108     {
 109       ed_key.l_addr = s->in2out.addr;
 110       ed_key.r_addr = s->ext_host_addr;
 111       ed_key.fib_index = s->in2out.fib_index;
 112       if (snat_is_unk_proto_session (s))
 113         {
 114           ed_key.proto = s->in2out.port;
 115           ed_key.r_port = 0;
 116           ed_key.l_port = 0;
 117         }
 118       else
 119         {
 120           ed_key.proto = snat_proto_to_ip_proto (s->in2out.protocol);
 121           ed_key.l_port = s->in2out.port;
 122           ed_key.r_port = s->ext_host_port;
 123         }
 124       if (is_twice_nat_session (s))
 125         {
 126           ed_key.r_addr = s->ext_host_nat_addr;
 127           ed_key.r_port = s->ext_host_nat_port;
 128         }
 129       ed_kv.key[0] = ed_key.as_u64[0];
 130       ed_kv.key[1] = ed_key.as_u64[1];
 131       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &ed_kv, 0))
 132         nat_elog_warn ("in2out_ed key del failed");
 133
 134       if (snat_is_unk_proto_session (s))
 135         goto delete;
 136
 137       snat_ipfix_logging_nat44_ses_delete (ctx->thread_index,
 138                                            s->in2out.addr.as_u32,
 139                                            s->out2in.addr.as_u32,
 140                                            s->in2out.protocol,
 141                                            s->in2out.port,
 142                                            s->out2in.port,
 143                                            s->in2out.fib_index);
 144
 145       nat_syslog_nat44_sdel (s->user_index, s->in2out.fib_index,
 146                              &s->in2out.addr, s->in2out.port,
 147                              &s->ext_host_nat_addr, s->ext_host_nat_port,
 148                              &s->out2in.addr, s->out2in.port,
 149                              &s->ext_host_addr, s->ext_host_port,
 150                              s->in2out.protocol, is_twice_nat_session (s));
 151
 152       nat_ha_sdel (&s->out2in.addr, s->out2in.port, &s->ext_host_addr,
 153                    s->ext_host_port, s->out2in.protocol, s->out2in.fib_index,
 154                    ctx->thread_index);
 155
 156       if (is_twice_nat_session (s))
 157         {
 158           for (i = 0; i < vec_len (sm->twice_nat_addresses); i++)
 159             {
 160               key.protocol = s->in2out.protocol;
 161               key.port = s->ext_host_nat_port;
 162               a = sm->twice_nat_addresses + i;
 163               if (a->addr.as_u32 == s->ext_host_nat_addr.as_u32)
 164                 {
 165                   snat_free_outside_address_and_port (sm->twice_nat_addresses,
 166                                                       ctx->thread_index,
 167                                                       &key);
 168                   break;
 169                 }
 170             }
 171         }
 172
 173       if (snat_is_session_static (s))
 174         goto delete;
 175
 176       snat_free_outside_address_and_port (sm->addresses, ctx->thread_index,
 177                                           &s->out2in);
 178     delete:
 179       nat44_delete_session (sm, s, ctx->thread_index);
 180       return 1;
 181     }
 182
 183   return 0;
 184 }
 185 #endif
 186
 187 static snat_session_t *
 188 create_session_for_static_mapping_ed (snat_main_t * sm,
 189                                       vlib_buffer_t * b,
 190                                       snat_session_key_t l_key,
 191                                       snat_session_key_t e_key,
 192                                       vlib_node_runtime_t * node,
 193                                       u32 thread_index,
 194                                       twice_nat_type_t twice_nat,
 195                                       lb_nat_type_t lb_nat, f64 now)
 196 {
 197   snat_session_t *s;
 198   snat_user_t *u;
 199   ip4_header_t *ip;
 200   udp_header_t *udp;
 201   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 202   clib_bihash_kv_16_8_t kv;
 203   snat_session_key_t eh_key;
 204   nat44_is_idle_session_ctx_t ctx;
 205
 206   if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
 207     {
 208       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 209       nat_elog_notice ("maximum sessions exceeded");
 210       return 0;
 211     }
 212
 213   u = nat_user_get_or_create (sm, &l_key.addr, l_key.fib_index, thread_index);
 214   if (!u)
 215     {
 216       nat_elog_warn ("create NAT user failed");
 217       return 0;
 218     }
 219
 220   s = nat_ed_session_alloc (sm, u, thread_index, now);
 221   if (!s)
 222     {
 223       nat44_delete_user_with_no_session (sm, u, thread_index);
 224       nat_elog_warn ("create NAT session failed");
 225       return 0;
 226     }
 227
 228   ip = vlib_buffer_get_current (b);
 229   udp = ip4_next_header (ip);
 230
 231   s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 232   s->ext_host_port = e_key.protocol == SNAT_PROTOCOL_ICMP ? 0 : udp->src_port;
 233   s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 234   if (lb_nat)
 235     s->flags |= SNAT_SESSION_FLAG_LOAD_BALANCING;
 236   if (lb_nat == AFFINITY_LB_NAT)
 237     s->flags |= SNAT_SESSION_FLAG_AFFINITY;
 238   s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 239   s->out2in = e_key;
 240   s->in2out = l_key;
 241   s->in2out.protocol = s->out2in.protocol;
 242   user_session_increment (sm, u, 1);
 243
 244   /* Add to lookup tables */
 245   make_ed_kv (&kv, &e_key.addr, &s->ext_host_addr, ip->protocol,
 246               e_key.fib_index, e_key.port, s->ext_host_port);
 247   kv.value = s - tsm->sessions;
 248   ctx.now = now;
 249   ctx.thread_index = thread_index;
 250   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->out2in_ed, &kv,
 251                                                nat44_o2i_ed_is_idle_session_cb,
 252                                                &ctx))
 253     nat_elog_notice ("out2in-ed key add failed");
 254
 255   if (twice_nat == TWICE_NAT || (twice_nat == TWICE_NAT_SELF &&
 256                                  ip->src_address.as_u32 == l_key.addr.as_u32))
 257     {
 258       eh_key.protocol = e_key.protocol;
 259       if (snat_alloc_outside_address_and_port (sm->twice_nat_addresses, 0,
 260                                                thread_index, &eh_key,
 261                                                sm->port_per_thread,
 262                                                tsm->snat_thread_index))
 263         {
 264           b->error = node->errors[NAT_OUT2IN_ED_ERROR_OUT_OF_PORTS];
 265           nat44_delete_session (sm, s, thread_index);
 266           if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &kv, 0))
 267             nat_elog_notice ("out2in-ed key del failed");
 268           return 0;
 269         }
 270       s->ext_host_nat_addr.as_u32 = eh_key.addr.as_u32;
 271       s->ext_host_nat_port = eh_key.port;
 272       s->flags |= SNAT_SESSION_FLAG_TWICE_NAT;
 273       make_ed_kv (&kv, &l_key.addr, &s->ext_host_nat_addr, ip->protocol,
 274                   l_key.fib_index, l_key.port, s->ext_host_nat_port);
 275     }
 276   else
 277     {
 278       make_ed_kv (&kv, &l_key.addr, &s->ext_host_addr, ip->protocol,
 279                   l_key.fib_index, l_key.port, s->ext_host_port);
 280     }
 281   kv.value = s - tsm->sessions;
 282   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->in2out_ed, &kv,
 283                                                nat44_i2o_ed_is_idle_session_cb,
 284                                                &ctx))
 285     nat_elog_notice ("in2out-ed key add failed");
 286
 287   snat_ipfix_logging_nat44_ses_create (thread_index,
 288                                        s->in2out.addr.as_u32,
 289                                        s->out2in.addr.as_u32,
 290                                        s->in2out.protocol,
 291                                        s->in2out.port,
 292                                        s->out2in.port, s->in2out.fib_index);
 293
 294   nat_syslog_nat44_sadd (s->user_index, s->in2out.fib_index,
 295                          &s->in2out.addr, s->in2out.port,
 296                          &s->ext_host_nat_addr, s->ext_host_nat_port,
 297                          &s->out2in.addr, s->out2in.port,
 298                          &s->ext_host_addr, s->ext_host_port,
 299                          s->in2out.protocol, is_twice_nat_session (s));
 300
 301   nat_ha_sadd (&s->in2out.addr, s->in2out.port, &s->out2in.addr,
 302                s->out2in.port, &s->ext_host_addr, s->ext_host_port,
 303                &s->ext_host_nat_addr, s->ext_host_nat_port,
 304                s->in2out.protocol, s->in2out.fib_index, s->flags,
 305                thread_index, 0);
 306
 307   return s;
 308 }
 309
 310 static int
 311 next_src_nat (snat_main_t * sm, ip4_header_t * ip, u8 proto, u16 src_port,
 312               u16 dst_port, u32 thread_index, u32 rx_fib_index)
 313 {
 314   clib_bihash_kv_16_8_t kv, value;
 315   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 316
 317   make_ed_kv (&kv, &ip->src_address, &ip->dst_address, proto,
 318               rx_fib_index, src_port, dst_port);
 319   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 320     return 1;
 321
 322   return 0;
 323 }
 324
 325 static void
 326 create_bypass_for_fwd (snat_main_t * sm, vlib_buffer_t * b, ip4_header_t * ip,
 327                        u32 rx_fib_index, u32 thread_index)
 328 {
 329   nat_ed_ses_key_t key;
 330   clib_bihash_kv_16_8_t kv, value;
 331   udp_header_t *udp;
 332   snat_user_t *u;
 333   snat_session_t *s = 0;
 334   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 335   f64 now = vlib_time_now (sm->vlib_main);
 336
 337   if (ip->protocol == IP_PROTOCOL_ICMP)
 338     {
 339       if (get_icmp_o2i_ed_key (b, ip, &key))
 340         return;
 341     }
 342   else if (ip->protocol == IP_PROTOCOL_UDP || ip->protocol == IP_PROTOCOL_TCP)
 343     {
 344       udp = ip4_next_header (ip);
 345       key.r_addr = ip->src_address;
 346       key.l_addr = ip->dst_address;
 347       key.proto = ip->protocol;
 348       key.l_port = udp->dst_port;
 349       key.r_port = udp->src_port;
 350     }
 351   else
 352     {
 353       key.r_addr = ip->src_address;
 354       key.l_addr = ip->dst_address;
 355       key.proto = ip->protocol;
 356       key.l_port = key.r_port = 0;
 357     }
 358   key.fib_index = 0;
 359   kv.key[0] = key.as_u64[0];
 360   kv.key[1] = key.as_u64[1];
 361
 362   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 363     {
 364       s = pool_elt_at_index (tsm->sessions, value.value);
 365     }
 366   else
 367     {
 368       u32 proto;
 369
 370       if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
 371         return;
 372
 373       u = nat_user_get_or_create (sm, &ip->dst_address, sm->inside_fib_index,
 374                                   thread_index);
 375       if (!u)
 376         {
 377           nat_elog_warn ("create NAT user failed");
 378           return;
 379         }
 380
 381       s = nat_ed_session_alloc (sm, u, thread_index, now);
 382       if (!s)
 383         {
 384           nat44_delete_user_with_no_session (sm, u, thread_index);
 385           nat_elog_warn ("create NAT session failed");
 386           return;
 387         }
 388
 389       proto = ip_proto_to_snat_proto (key.proto);
 390
 391       s->ext_host_addr = key.r_addr;
 392       s->ext_host_port = key.r_port;
 393       s->flags |= SNAT_SESSION_FLAG_FWD_BYPASS;
 394       s->out2in.addr = key.l_addr;
 395       s->out2in.port = key.l_port;
 396       s->out2in.protocol = proto;
 397       if (proto == ~0)
 398         {
 399           s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 400           s->out2in.port = ip->protocol;
 401         }
 402       s->out2in.fib_index = 0;
 403       s->in2out = s->out2in;
 404       user_session_increment (sm, u, 0);
 405
 406       kv.value = s - tsm->sessions;
 407       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &kv, 1))
 408         nat_elog_notice ("in2out_ed key add failed");
 409     }
 410
 411   if (ip->protocol == IP_PROTOCOL_TCP)
 412     {
 413       tcp_header_t *tcp = ip4_next_header (ip);
 414       if (nat44_set_tcp_session_state_o2i
 415           (sm, s, tcp->flags, tcp->ack_number, tcp->seq_number, thread_index))
 416         return;
 417     }
 418
 419   /* Accounting */
 420   nat44_session_update_counters (s, now, 0, thread_index);
 421   /* Per-user LRU list maintenance */
 422   nat44_session_update_lru (sm, s, thread_index);
 423 }
 424
 425 static inline void
 426 create_bypass_for_fwd_worker (snat_main_t * sm, vlib_buffer_t * b,
 427                               ip4_header_t * ip, u32 rx_fib_index)
 428 {
 429   ip4_header_t ip_wkr = {
 430     .src_address = ip->dst_address,
 431   };
 432   u32 thread_index = sm->worker_in2out_cb (&ip_wkr, rx_fib_index, 0);
 433
 434   create_bypass_for_fwd (sm, b, ip, rx_fib_index, thread_index);
 435 }
 436
 437 #ifndef CLIB_MARCH_VARIANT
 438 u32
 439 icmp_match_out2in_ed (snat_main_t * sm, vlib_node_runtime_t * node,
 440                       u32 thread_index, vlib_buffer_t * b, ip4_header_t * ip,
 441                       u8 * p_proto, snat_session_key_t * p_value,
 442                       u8 * p_dont_translate, void *d, void *e)
 443 {
 444   u32 next = ~0, sw_if_index, rx_fib_index;
 445   nat_ed_ses_key_t key;
 446   clib_bihash_kv_16_8_t kv, value;
 447   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 448   snat_session_t *s = 0;
 449   u8 dont_translate = 0, is_addr_only, identity_nat;
 450   snat_session_key_t e_key, l_key;
 451
 452   sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
 453   rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 454
 455   if (get_icmp_o2i_ed_key (b, ip, &key))
 456     {
 457       b->error = node->errors[NAT_OUT2IN_ED_ERROR_UNSUPPORTED_PROTOCOL];
 458       next = NAT_NEXT_DROP;
 459       goto out;
 460     }
 461   key.fib_index = rx_fib_index;
 462   kv.key[0] = key.as_u64[0];
 463   kv.key[1] = key.as_u64[1];
 464
 465   if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv, &value))
 466     {
 467       /* Try to match static mapping */
 468       e_key.addr = ip->dst_address;
 469       e_key.port = key.l_port;
 470       e_key.protocol = ip_proto_to_snat_proto (key.proto);
 471       e_key.fib_index = rx_fib_index;
 472       if (snat_static_mapping_match
 473           (sm, e_key, &l_key, 1, &is_addr_only, 0, 0, 0, &identity_nat))
 474         {
 475           if (!sm->forwarding_enabled)
 476             {
 477               /* Don't NAT packet aimed at the intfc address */
 478               if (PREDICT_FALSE (is_interface_addr (sm, node, sw_if_index,
 479                                                     ip->dst_address.as_u32)))
 480                 {
 481                   dont_translate = 1;
 482                   goto out;
 483                 }
 484               b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 485               next = NAT_NEXT_DROP;
 486               goto out;
 487             }
 488           else
 489             {
 490               dont_translate = 1;
 491               if (next_src_nat (sm, ip, key.proto, key.l_port, key.r_port,
 492                                 thread_index, rx_fib_index))
 493                 {
 494                   next = NAT_NEXT_IN2OUT_ED_FAST_PATH;
 495                   goto out;
 496                 }
 497               if (sm->num_workers > 1)
 498                 create_bypass_for_fwd_worker (sm, b, ip, rx_fib_index);
 499               else
 500                 create_bypass_for_fwd (sm, b, ip, rx_fib_index, thread_index);
 501               goto out;
 502             }
 503         }
 504
 505       if (PREDICT_FALSE
 506           (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 507            ICMP4_echo_reply
 508            && (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 509                ICMP4_echo_request || !is_addr_only)))
 510         {
 511           b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 512           next = NAT_NEXT_DROP;
 513           goto out;
 514         }
 515
 516       if (PREDICT_FALSE (identity_nat))
 517         {
 518           dont_translate = 1;
 519           goto out;
 520         }
 521
 522       /* Create session initiated by host from external network */
 523       s = create_session_for_static_mapping_ed (sm, b, l_key, e_key, node,
 524                                                 thread_index, 0, 0,
 525                                                 vlib_time_now
 526                                                 (sm->vlib_main));
 527
 528       if (!s)
 529         {
 530           next = NAT_NEXT_DROP;
 531           goto out;
 532         }
 533     }
 534   else
 535     {
 536       if (PREDICT_FALSE
 537           (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 538            ICMP4_echo_reply
 539            && vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 540            ICMP4_echo_request
 541            && !icmp_type_is_error_message (vnet_buffer (b)->ip.
 542                                            reass.icmp_type_or_tcp_flags)))
 543         {
 544           b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 545           next = NAT_NEXT_DROP;
 546           goto out;
 547         }
 548
 549       s = pool_elt_at_index (tsm->sessions, value.value);
 550     }
 551
 552   *p_proto = ip_proto_to_snat_proto (key.proto);
 553 out:
 554   if (s)
 555     *p_value = s->in2out;
 556   *p_dont_translate = dont_translate;
 557   if (d)
 558     *(snat_session_t **) d = s;
 559   return next;
 560 }
 561 #endif
 562
 563 static snat_session_t *
 564 nat44_ed_out2in_unknown_proto (snat_main_t * sm,
 565                                vlib_buffer_t * b,
 566                                ip4_header_t * ip,
 567                                u32 rx_fib_index,
 568                                u32 thread_index,
 569                                f64 now,
 570                                vlib_main_t * vm, vlib_node_runtime_t * node)
 571 {
 572   clib_bihash_kv_8_8_t kv, value;
 573   clib_bihash_kv_16_8_t s_kv, s_value;
 574   snat_static_mapping_t *m;
 575   u32 old_addr, new_addr;
 576   ip_csum_t sum;
 577   snat_session_t *s;
 578   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 579   snat_user_t *u;
 580
 581   old_addr = ip->dst_address.as_u32;
 582
 583   make_ed_kv (&s_kv, &ip->dst_address, &ip->src_address, ip->protocol,
 584               rx_fib_index, 0, 0);
 585
 586   if (!clib_bihash_search_16_8 (&tsm->out2in_ed, &s_kv, &s_value))
 587     {
 588       s = pool_elt_at_index (tsm->sessions, s_value.value);
 589       new_addr = ip->dst_address.as_u32 = s->in2out.addr.as_u32;
 590     }
 591   else
 592     {
 593       if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
 594         {
 595           b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 596           nat_elog_notice ("maximum sessions exceeded");
 597           return 0;
 598         }
 599
 600       make_sm_kv (&kv, &ip->dst_address, 0, 0, 0);
 601       if (clib_bihash_search_8_8
 602           (&sm->static_mapping_by_external, &kv, &value))
 603         {
 604           b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 605           return 0;
 606         }
 607
 608       m = pool_elt_at_index (sm->static_mappings, value.value);
 609
 610       new_addr = ip->dst_address.as_u32 = m->local_addr.as_u32;
 611
 612       u = nat_user_get_or_create (sm, &m->local_addr, m->fib_index,
 613                                   thread_index);
 614       if (!u)
 615         {
 616           nat_elog_warn ("create NAT user failed");
 617           return 0;
 618         }
 619
 620       /* Create a new session */
 621       s = nat_ed_session_alloc (sm, u, thread_index, now);
 622       if (!s)
 623         {
 624           nat44_delete_user_with_no_session (sm, u, thread_index);
 625           nat_elog_warn ("create NAT session failed");
 626           return 0;
 627         }
 628
 629       s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 630       s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 631       s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 632       s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 633       s->out2in.addr.as_u32 = old_addr;
 634       s->out2in.fib_index = rx_fib_index;
 635       s->in2out.addr.as_u32 = new_addr;
 636       s->in2out.fib_index = m->fib_index;
 637       s->in2out.port = s->out2in.port = ip->protocol;
 638       user_session_increment (sm, u, 1);
 639
 640       /* Add to lookup tables */
 641       s_kv.value = s - tsm->sessions;
 642       if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &s_kv, 1))
 643         nat_elog_notice ("out2in key add failed");
 644
 645       make_ed_kv (&s_kv, &ip->dst_address, &ip->src_address, ip->protocol,
 646                   m->fib_index, 0, 0);
 647       s_kv.value = s - tsm->sessions;
 648       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &s_kv, 1))
 649         nat_elog_notice ("in2out key add failed");
 650     }
 651
 652   /* Update IP checksum */
 653   sum = ip->checksum;
 654   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
 655   ip->checksum = ip_csum_fold (sum);
 656
 657   vnet_buffer (b)->sw_if_index[VLIB_TX] = s->in2out.fib_index;
 658
 659   /* Accounting */
 660   nat44_session_update_counters (s, now, vlib_buffer_length_in_chain (vm, b),
 661                                  thread_index);
 662   /* Per-user LRU list maintenance */
 663   nat44_session_update_lru (sm, s, thread_index);
 664
 665   return s;
 666 }
 667
 668 static inline uword
 669 nat44_ed_out2in_fast_path_node_fn_inline (vlib_main_t * vm,
 670                                           vlib_node_runtime_t * node,
 671                                           vlib_frame_t * frame)
 672 {
 673   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
 674   nat_next_t next_index;
 675   snat_main_t *sm = &snat_main;
 676   f64 now = vlib_time_now (vm);
 677   u32 thread_index = vm->thread_index;
 678   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 679   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 680     0, fragments = 0;
 681
 682   stats_node_index = sm->ed_out2in_node_index;
 683
 684   from = vlib_frame_vector_args (frame);
 685   n_left_from = frame->n_vectors;
 686   next_index = node->cached_next_index;
 687
 688   while (n_left_from > 0)
 689     {
 690       u32 n_left_to_next;
 691
 692       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 693
 694       while (n_left_from > 0 && n_left_to_next > 0)
 695         {
 696           u32 bi0;
 697           vlib_buffer_t *b0;
 698           u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
 699             new_addr0;
 700           u16 old_port0, new_port0;
 701           ip4_header_t *ip0;
 702           udp_header_t *udp0;
 703           tcp_header_t *tcp0;
 704           snat_session_t *s0 = 0;
 705           clib_bihash_kv_16_8_t kv0, value0;
 706           ip_csum_t sum0;
 707
 708           /* speculatively enqueue b0 to the current next frame */
 709           bi0 = from[0];
 710           to_next[0] = bi0;
 711           from += 1;
 712           to_next += 1;
 713           n_left_from -= 1;
 714           n_left_to_next -= 1;
 715
 716           b0 = vlib_get_buffer (vm, bi0);
 717           next0 = nat_buffer_opaque (b0)->arc_next;
 718
 719           vnet_buffer (b0)->snat.flags = 0;
 720           ip0 = vlib_buffer_get_current (b0);
 721
 722           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 723           rx_fib_index0 =
 724             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 725                                                  sw_if_index0);
 726
 727           if (PREDICT_FALSE (ip0->ttl == 1))
 728             {
 729               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 730               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 731                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 732                                            0);
 733               next0 = NAT_NEXT_ICMP_ERROR;
 734               goto trace0;
 735             }
 736
 737           udp0 = ip4_next_header (ip0);
 738           tcp0 = (tcp_header_t *) udp0;
 739           proto0 = ip_proto_to_snat_proto (ip0->protocol);
 740
 741           if (PREDICT_FALSE (proto0 == ~0))
 742             {
 743               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 744               goto trace0;
 745             }
 746
 747           if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
 748             {
 749               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 750               goto trace0;
 751             }
 752
 753           make_ed_kv (&kv0, &ip0->dst_address, &ip0->src_address,
 754                       ip0->protocol, rx_fib_index0,
 755                       vnet_buffer (b0)->ip.reass.l4_dst_port,
 756                       vnet_buffer (b0)->ip.reass.l4_src_port);
 757
 758           if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv0, &value0))
 759             {
 760               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 761               goto trace0;
 762             }
 763           s0 = pool_elt_at_index (tsm->sessions, value0.value);
 764
 765           // drop if session expired
 766           u64 sess_timeout_time;
 767           sess_timeout_time = s0->last_heard +
 768             (f64) nat44_session_get_timeout (sm, s0);
 769           if (now >= sess_timeout_time)
 770             {
 771               // delete session
 772               nat_free_session_data (sm, s0, thread_index, 0);
 773               nat44_delete_session (sm, s0, thread_index);
 774
 775               next0 = NAT_NEXT_DROP;
 776               goto trace0;
 777             }
 778           //
 779
 780           old_addr0 = ip0->dst_address.as_u32;
 781           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
 782           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
 783
 784           sum0 = ip0->checksum;
 785           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 786                                  dst_address);
 787           if (PREDICT_FALSE (is_twice_nat_session (s0)))
 788             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 789                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
 790                                    src_address);
 791           ip0->checksum = ip_csum_fold (sum0);
 792
 793           old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
 794
 795           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
 796             {
 797               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 798                 {
 799                   new_port0 = udp0->dst_port = s0->in2out.port;
 800                   sum0 = tcp0->checksum;
 801                   sum0 =
 802                     ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 803                                     dst_address);
 804                   sum0 =
 805                     ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 806                                     length);
 807                   if (is_twice_nat_session (s0))
 808                     {
 809                       sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 810                                              s0->ext_host_nat_addr.as_u32,
 811                                              ip4_header_t, dst_address);
 812                       sum0 =
 813                         ip_csum_update (sum0,
 814                                         vnet_buffer (b0)->ip.
 815                                         reass.l4_src_port,
 816                                         s0->ext_host_nat_port, ip4_header_t,
 817                                         length);
 818                       tcp0->src_port = s0->ext_host_nat_port;
 819                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 820                     }
 821                   tcp0->checksum = ip_csum_fold (sum0);
 822                 }
 823               tcp_packets++;
 824               if (nat44_set_tcp_session_state_o2i
 825                   (sm, s0, vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags,
 826                    vnet_buffer (b0)->ip.reass.tcp_ack_number,
 827                    vnet_buffer (b0)->ip.reass.tcp_seq_number, thread_index))
 828                 goto trace0;
 829             }
 830           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
 831                    && udp0->checksum)
 832             {
 833               new_port0 = udp0->dst_port = s0->in2out.port;
 834               sum0 = udp0->checksum;
 835               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 836                                      dst_address);
 837               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 838                                      length);
 839               if (PREDICT_FALSE (is_twice_nat_session (s0)))
 840                 {
 841                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 842                                          s0->ext_host_nat_addr.as_u32,
 843                                          ip4_header_t, dst_address);
 844                   sum0 =
 845                     ip_csum_update (sum0,
 846                                     vnet_buffer (b0)->ip.reass.l4_src_port,
 847                                     s0->ext_host_nat_port, ip4_header_t,
 848                                     length);
 849                   udp0->src_port = s0->ext_host_nat_port;
 850                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 851                 }
 852               udp0->checksum = ip_csum_fold (sum0);
 853               udp_packets++;
 854             }
 855           else
 856             {
 857               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 858                 {
 859                   new_port0 = udp0->dst_port = s0->in2out.port;
 860                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
 861                     {
 862                       udp0->src_port = s0->ext_host_nat_port;
 863                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 864                     }
 865                 }
 866               udp_packets++;
 867             }
 868
 869           /* Accounting */
 870           nat44_session_update_counters (s0, now,
 871                                          vlib_buffer_length_in_chain (vm, b0),
 872                                          thread_index);
 873           /* Per-user LRU list maintenance */
 874           nat44_session_update_lru (sm, s0, thread_index);
 875
 876         trace0:
 877           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 878                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 879             {
 880               nat44_ed_out2in_trace_t *t =
 881                 vlib_add_trace (vm, node, b0, sizeof (*t));
 882               t->sw_if_index = sw_if_index0;
 883               t->next_index = next0;
 884               t->is_slow_path = 0;
 885
 886               if (s0)
 887                 t->session_index = s0 - tsm->sessions;
 888               else
 889                 t->session_index = ~0;
 890             }
 891
 892           pkts_processed += next0 == nat_buffer_opaque (b0)->arc_next;
 893           /* verify speculative enqueue, maybe switch current next frame */
 894           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 895                                            to_next, n_left_to_next,
 896                                            bi0, next0);
 897         }
 898
 899       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 900     }
 901
 902   vlib_node_increment_counter (vm, stats_node_index,
 903                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
 904                                pkts_processed);
 905   vlib_node_increment_counter (vm, stats_node_index,
 906                                NAT_OUT2IN_ED_ERROR_TCP_PACKETS, tcp_packets);
 907   vlib_node_increment_counter (vm, stats_node_index,
 908                                NAT_OUT2IN_ED_ERROR_UDP_PACKETS, udp_packets);
 909   vlib_node_increment_counter (vm, stats_node_index,
 910                                NAT_OUT2IN_ED_ERROR_ICMP_PACKETS,
 911                                icmp_packets);
 912   vlib_node_increment_counter (vm, stats_node_index,
 913                                NAT_OUT2IN_ED_ERROR_OTHER_PACKETS,
 914                                other_packets);
 915   vlib_node_increment_counter (vm, stats_node_index,
 916                                NAT_OUT2IN_ED_ERROR_FRAGMENTS, fragments);
 917   return frame->n_vectors;
 918 }
 919
 920 static inline uword
 921 nat44_ed_out2in_slow_path_node_fn_inline (vlib_main_t * vm,
 922                                           vlib_node_runtime_t * node,
 923                                           vlib_frame_t * frame)
 924 {
 925   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
 926   nat_next_t next_index;
 927   snat_main_t *sm = &snat_main;
 928   f64 now = vlib_time_now (vm);
 929   u32 thread_index = vm->thread_index;
 930   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 931   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 932     0, fragments = 0;
 933
 934   stats_node_index = sm->ed_out2in_slowpath_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, proto0, old_addr0,
 951             new_addr0;
 952           u16 old_port0, new_port0;
 953           ip4_header_t *ip0;
 954           udp_header_t *udp0;
 955           tcp_header_t *tcp0;
 956           icmp46_header_t *icmp0;
 957           snat_session_t *s0 = 0;
 958           clib_bihash_kv_16_8_t kv0, value0;
 959           ip_csum_t sum0;
 960           snat_session_key_t e_key0, l_key0;
 961           lb_nat_type_t lb_nat0;
 962           twice_nat_type_t twice_nat0;
 963           u8 identity_nat0;
 964
 965           /* speculatively enqueue b0 to the current next frame */
 966           bi0 = from[0];
 967           to_next[0] = bi0;
 968           from += 1;
 969           to_next += 1;
 970           n_left_from -= 1;
 971           n_left_to_next -= 1;
 972
 973           b0 = vlib_get_buffer (vm, bi0);
 974           next0 = nat_buffer_opaque (b0)->arc_next;
 975
 976           vnet_buffer (b0)->snat.flags = 0;
 977           ip0 = vlib_buffer_get_current (b0);
 978
 979           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 980           rx_fib_index0 =
 981             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 982                                                  sw_if_index0);
 983
 984           if (PREDICT_FALSE (ip0->ttl == 1))
 985             {
 986               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 987               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 988                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 989                                            0);
 990               next0 = NAT_NEXT_ICMP_ERROR;
 991               goto trace0;
 992             }
 993
 994           udp0 = ip4_next_header (ip0);
 995           tcp0 = (tcp_header_t *) udp0;
 996           icmp0 = (icmp46_header_t *) udp0;
 997           proto0 = ip_proto_to_snat_proto (ip0->protocol);
 998
 999           if (PREDICT_FALSE (proto0 == ~0))
1000             {
1001               s0 =
1002                 nat44_ed_out2in_unknown_proto (sm, b0, ip0, rx_fib_index0,
1003                                                thread_index, now, vm, node);
1004               other_packets++;
1005               if (!sm->forwarding_enabled)
1006                 {
1007                   if (!s0)
1008                     next0 = NAT_NEXT_DROP;
1009                   goto trace0;
1010                 }
1011             }
1012
1013           if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1014             {
1015               next0 = icmp_out2in_ed_slow_path
1016                 (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1017                  next0, now, thread_index, &s0);
1018               icmp_packets++;
1019               goto trace0;
1020             }
1021
1022           make_ed_kv (&kv0, &ip0->dst_address, &ip0->src_address,
1023                       ip0->protocol, rx_fib_index0,
1024                       vnet_buffer (b0)->ip.reass.l4_dst_port,
1025                       vnet_buffer (b0)->ip.reass.l4_src_port);
1026
1027           if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv0, &value0))
1028             {
1029               /* Try to match static mapping by external address and port,
1030                  destination address and port in packet */
1031               e_key0.addr = ip0->dst_address;
1032               e_key0.port = vnet_buffer (b0)->ip.reass.l4_dst_port;
1033               e_key0.protocol = proto0;
1034               e_key0.fib_index = rx_fib_index0;
1035
1036               if (snat_static_mapping_match (sm, e_key0, &l_key0, 1, 0,
1037                                              &twice_nat0, &lb_nat0,
1038                                              &ip0->src_address,
1039                                              &identity_nat0))
1040                 {
1041                   /*
1042                    * Send DHCP packets to the ipv4 stack, or we won't
1043                    * be able to use dhcp client on the outside interface
1044                    */
1045                   if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_UDP
1046                                      && (vnet_buffer (b0)->ip.
1047                                          reass.l4_dst_port ==
1048                                          clib_host_to_net_u16
1049                                          (UDP_DST_PORT_dhcp_to_client))))
1050                     {
1051                       goto trace0;
1052                     }
1053
1054                   if (!sm->forwarding_enabled)
1055                     {
1056                       b0->error =
1057                         node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
1058                       next0 = NAT_NEXT_DROP;
1059                     }
1060                   else
1061                     {
1062                       if (next_src_nat (sm, ip0, ip0->protocol,
1063                                         vnet_buffer (b0)->ip.
1064                                         reass.l4_src_port,
1065                                         vnet_buffer (b0)->ip.
1066                                         reass.l4_dst_port, thread_index,
1067                                         rx_fib_index0))
1068                         {
1069                           next0 = NAT_NEXT_IN2OUT_ED_FAST_PATH;
1070                           goto trace0;
1071                         }
1072                       if (sm->num_workers > 1)
1073                         create_bypass_for_fwd_worker (sm, b0, ip0,
1074                                                       rx_fib_index0);
1075                       else
1076                         create_bypass_for_fwd (sm, b0, ip0, rx_fib_index0,
1077                                                thread_index);
1078                     }
1079                   goto trace0;
1080                 }
1081
1082               if (PREDICT_FALSE (identity_nat0))
1083                 goto trace0;
1084
1085               if ((proto0 == SNAT_PROTOCOL_TCP)
1086                   && !tcp_flags_is_init (vnet_buffer (b0)->ip.
1087                                          reass.icmp_type_or_tcp_flags))
1088                 {
1089                   b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
1090                   next0 = NAT_NEXT_DROP;
1091                   goto trace0;
1092                 }
1093
1094               /* Create session initiated by host from external network */
1095               s0 = create_session_for_static_mapping_ed (sm, b0, l_key0,
1096                                                          e_key0, node,
1097                                                          thread_index,
1098                                                          twice_nat0,
1099                                                          lb_nat0, now);
1100               if (!s0)
1101                 {
1102                   next0 = NAT_NEXT_DROP;
1103                   goto trace0;
1104                 }
1105             }
1106           else
1107             {
1108               s0 = pool_elt_at_index (tsm->sessions, value0.value);
1109             }
1110
1111           old_addr0 = ip0->dst_address.as_u32;
1112           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
1113           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
1114
1115           sum0 = ip0->checksum;
1116           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1117                                  dst_address);
1118           if (PREDICT_FALSE (is_twice_nat_session (s0)))
1119             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1120                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
1121                                    src_address);
1122           ip0->checksum = ip_csum_fold (sum0);
1123
1124           old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
1125
1126           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
1127             {
1128               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1129                 {
1130                   new_port0 = udp0->dst_port = s0->in2out.port;
1131                   sum0 = tcp0->checksum;
1132                   sum0 =
1133                     ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1134                                     dst_address);
1135                   sum0 =
1136                     ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1137                                     length);
1138                   if (is_twice_nat_session (s0))
1139                     {
1140                       sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1141                                              s0->ext_host_nat_addr.as_u32,
1142                                              ip4_header_t, dst_address);
1143                       sum0 =
1144                         ip_csum_update (sum0,
1145                                         vnet_buffer (b0)->ip.
1146                                         reass.l4_src_port,
1147                                         s0->ext_host_nat_port, ip4_header_t,
1148                                         length);
1149                       tcp0->src_port = s0->ext_host_nat_port;
1150                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1151                     }
1152                   tcp0->checksum = ip_csum_fold (sum0);
1153                 }
1154               tcp_packets++;
1155               if (nat44_set_tcp_session_state_o2i
1156                   (sm, s0, vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags,
1157                    vnet_buffer (b0)->ip.reass.tcp_ack_number,
1158                    vnet_buffer (b0)->ip.reass.tcp_seq_number, thread_index))
1159                 goto trace0;
1160             }
1161           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
1162                    && udp0->checksum)
1163             {
1164               new_port0 = udp0->dst_port = s0->in2out.port;
1165               sum0 = udp0->checksum;
1166               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1167                                      dst_address);
1168               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1169                                      length);
1170               if (PREDICT_FALSE (is_twice_nat_session (s0)))
1171                 {
1172                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1173                                          s0->ext_host_nat_addr.as_u32,
1174                                          ip4_header_t, dst_address);
1175                   sum0 =
1176                     ip_csum_update (sum0,
1177                                     vnet_buffer (b0)->ip.reass.l4_src_port,
1178                                     s0->ext_host_nat_port, ip4_header_t,
1179                                     length);
1180                   udp0->src_port = s0->ext_host_nat_port;
1181                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1182                 }
1183               udp0->checksum = ip_csum_fold (sum0);
1184               udp_packets++;
1185             }
1186           else
1187             {
1188               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1189                 {
1190                   new_port0 = udp0->dst_port = s0->in2out.port;
1191                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
1192                     {
1193                       udp0->src_port = s0->ext_host_nat_port;
1194                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1195                     }
1196                 }
1197               udp_packets++;
1198             }
1199
1200           /* Accounting */
1201           nat44_session_update_counters (s0, now,
1202                                          vlib_buffer_length_in_chain (vm, b0),
1203                                          thread_index);
1204           /* Per-user LRU list maintenance */
1205           nat44_session_update_lru (sm, s0, thread_index);
1206
1207         trace0:
1208           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1209                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1210             {
1211               nat44_ed_out2in_trace_t *t =
1212                 vlib_add_trace (vm, node, b0, sizeof (*t));
1213               t->sw_if_index = sw_if_index0;
1214               t->next_index = next0;
1215               t->is_slow_path = 1;
1216
1217               if (s0)
1218                 t->session_index = s0 - tsm->sessions;
1219               else
1220                 t->session_index = ~0;
1221             }
1222
1223           pkts_processed += next0 == nat_buffer_opaque (b0)->arc_next;
1224           /* verify speculative enqueue, maybe switch current next frame */
1225           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1226                                            to_next, n_left_to_next,
1227                                            bi0, next0);
1228         }
1229
1230       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1231     }
1232
1233   vlib_node_increment_counter (vm, stats_node_index,
1234                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
1235                                pkts_processed);
1236   vlib_node_increment_counter (vm, stats_node_index,
1237                                NAT_OUT2IN_ED_ERROR_TCP_PACKETS, tcp_packets);
1238   vlib_node_increment_counter (vm, stats_node_index,
1239                                NAT_OUT2IN_ED_ERROR_UDP_PACKETS, udp_packets);
1240   vlib_node_increment_counter (vm, stats_node_index,
1241                                NAT_OUT2IN_ED_ERROR_ICMP_PACKETS,
1242                                icmp_packets);
1243   vlib_node_increment_counter (vm, stats_node_index,
1244                                NAT_OUT2IN_ED_ERROR_OTHER_PACKETS,
1245                                other_packets);
1246   vlib_node_increment_counter (vm, stats_node_index,
1247                                NAT_OUT2IN_ED_ERROR_FRAGMENTS, fragments);
1248   return frame->n_vectors;
1249 }
1250
1251 VLIB_NODE_FN (nat44_ed_out2in_node) (vlib_main_t * vm,
1252                                      vlib_node_runtime_t * node,
1253                                      vlib_frame_t * frame)
1254 {
1255   return nat44_ed_out2in_fast_path_node_fn_inline (vm, node, frame);
1256 }
1257
1258 /* *INDENT-OFF* */
1259 VLIB_REGISTER_NODE (nat44_ed_out2in_node) = {
1260   .name = "nat44-ed-out2in",
1261   .vector_size = sizeof (u32),
1262   .sibling_of = "nat-default",
1263   .format_trace = format_nat44_ed_out2in_trace,
1264   .type = VLIB_NODE_TYPE_INTERNAL,
1265   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1266   .error_strings = nat_out2in_ed_error_strings,
1267   .runtime_data_bytes = sizeof (snat_runtime_t),
1268 };
1269 /* *INDENT-ON* */
1270
1271 VLIB_NODE_FN (nat44_ed_out2in_slowpath_node) (vlib_main_t * vm,
1272                                               vlib_node_runtime_t * node,
1273                                               vlib_frame_t * frame)
1274 {
1275   return nat44_ed_out2in_slow_path_node_fn_inline (vm, node, frame);
1276 }
1277
1278 /* *INDENT-OFF* */
1279 VLIB_REGISTER_NODE (nat44_ed_out2in_slowpath_node) = {
1280   .name = "nat44-ed-out2in-slowpath",
1281   .vector_size = sizeof (u32),
1282   .sibling_of = "nat-default",
1283   .format_trace = format_nat44_ed_out2in_trace,
1284   .type = VLIB_NODE_TYPE_INTERNAL,
1285   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1286   .error_strings = nat_out2in_ed_error_strings,
1287   .runtime_data_bytes = sizeof (snat_runtime_t),
1288 };
1289 /* *INDENT-ON* */
1290
1291 static u8 *
1292 format_nat_pre_trace (u8 * s, va_list * args)
1293 {
1294   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1295   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1296   nat_pre_trace_t *t = va_arg (*args, nat_pre_trace_t *);
1297   return format (s, "out2in next_index %d", t->next_index);
1298 }
1299
1300 VLIB_NODE_FN (nat_pre_out2in_node) (vlib_main_t * vm,
1301                                     vlib_node_runtime_t * node,
1302                                     vlib_frame_t * frame)
1303 {
1304   return nat_pre_node_fn_inline (vm, node, frame,
1305                                  NAT_NEXT_OUT2IN_ED_FAST_PATH);
1306 }
1307
1308 /* *INDENT-OFF* */
1309 VLIB_REGISTER_NODE (nat_pre_out2in_node) = {
1310   .name = "nat-pre-out2in",
1311   .vector_size = sizeof (u32),
1312   .sibling_of = "nat-default",
1313   .format_trace = format_nat_pre_trace,
1314   .type = VLIB_NODE_TYPE_INTERNAL,
1315   .n_errors = 0,
1316  };
1317 /* *INDENT-ON* */
1318
1319 /*
1320  * fd.io coding-style-patch-verification: ON
1321  *
1322  * Local Variables:
1323  * eval: (c-set-style "gnu")
1324  * End:
1325  */