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 #include <nat/nat44/ed_inlines.h>
  35
  36 static char *nat_out2in_ed_error_strings[] = {
  37 #define _(sym,string) string,
  38   foreach_nat_out2in_ed_error
  39 #undef _
  40 };
  41
  42 typedef struct
  43 {
  44   u32 sw_if_index;
  45   u32 next_index;
  46   u32 session_index;
  47   u32 is_slow_path;
  48 } nat44_ed_out2in_trace_t;
  49
  50 static u8 *
  51 format_nat44_ed_out2in_trace (u8 * s, va_list * args)
  52 {
  53   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  54   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  55   nat44_ed_out2in_trace_t *t = va_arg (*args, nat44_ed_out2in_trace_t *);
  56   char *tag;
  57
  58   tag =
  59     t->is_slow_path ? "NAT44_OUT2IN_ED_SLOW_PATH" :
  60     "NAT44_OUT2IN_ED_FAST_PATH";
  61
  62   s = format (s, "%s: sw_if_index %d, next index %d, session %d", tag,
  63               t->sw_if_index, t->next_index, t->session_index);
  64
  65   return s;
  66 }
  67
  68 static inline u32
  69 icmp_out2in_ed_slow_path (snat_main_t * sm, vlib_buffer_t * b0,
  70                           ip4_header_t * ip0, icmp46_header_t * icmp0,
  71                           u32 sw_if_index0, u32 rx_fib_index0,
  72                           vlib_node_runtime_t * node, u32 next0, f64 now,
  73                           u32 thread_index, snat_session_t ** p_s0)
  74 {
  75   vlib_main_t *vm = vlib_get_main ();
  76
  77   next0 = icmp_out2in (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
  78                        next0, thread_index, p_s0, 0);
  79   snat_session_t *s0 = *p_s0;
  80   if (PREDICT_TRUE (next0 != NAT_NEXT_DROP && s0))
  81     {
  82       /* Accounting */
  83       nat44_session_update_counters (s0, now,
  84                                      vlib_buffer_length_in_chain
  85                                      (vm, b0), thread_index);
  86       /* Per-user LRU list maintenance */
  87       nat44_session_update_lru (sm, s0, thread_index);
  88     }
  89   return next0;
  90 }
  91
  92 #ifndef CLIB_MARCH_VARIANT
  93 int
  94 nat44_o2i_ed_is_idle_session_cb (clib_bihash_kv_16_8_t * kv, void *arg)
  95 {
  96   snat_main_t *sm = &snat_main;
  97   nat44_is_idle_session_ctx_t *ctx = arg;
  98   snat_session_t *s;
  99   u64 sess_timeout_time;
 100   u8 proto;
 101   u16 r_port, l_port;
 102   ip4_address_t *l_addr, *r_addr;
 103   u32 fib_index;
 104   clib_bihash_kv_16_8_t ed_kv;
 105   int i;
 106   snat_address_t *a;
 107   snat_session_key_t key;
 108   snat_main_per_thread_data_t *tsm = vec_elt_at_index (sm->per_thread_data,
 109                                                        ctx->thread_index);
 110
 111   s = pool_elt_at_index (tsm->sessions, kv->value);
 112   sess_timeout_time = s->last_heard + (f64) nat44_session_get_timeout (sm, s);
 113   if (ctx->now >= sess_timeout_time)
 114     {
 115       l_addr = &s->in2out.addr;
 116       r_addr = &s->ext_host_addr;
 117       fib_index = s->in2out.fib_index;
 118       if (snat_is_unk_proto_session (s))
 119         {
 120           proto = s->in2out.port;
 121           r_port = 0;
 122           l_port = 0;
 123         }
 124       else
 125         {
 126           proto = nat_proto_to_ip_proto (s->in2out.protocol);
 127           l_port = s->in2out.port;
 128           r_port = s->ext_host_port;
 129         }
 130       if (is_twice_nat_session (s))
 131         {
 132           r_addr = &s->ext_host_nat_addr;
 133           r_port = s->ext_host_nat_port;
 134         }
 135       make_ed_kv (l_addr, r_addr, proto, fib_index, l_port, r_port, ~0ULL,
 136                   &ed_kv);
 137       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &ed_kv, 0))
 138         nat_elog_warn ("in2out_ed key del failed");
 139
 140       if (snat_is_unk_proto_session (s))
 141         goto delete;
 142
 143       snat_ipfix_logging_nat44_ses_delete (ctx->thread_index,
 144                                            s->in2out.addr.as_u32,
 145                                            s->out2in.addr.as_u32,
 146                                            s->in2out.protocol,
 147                                            s->in2out.port,
 148                                            s->out2in.port,
 149                                            s->in2out.fib_index);
 150
 151       nat_syslog_nat44_sdel (s->user_index, s->in2out.fib_index,
 152                              &s->in2out.addr, s->in2out.port,
 153                              &s->ext_host_nat_addr, s->ext_host_nat_port,
 154                              &s->out2in.addr, s->out2in.port,
 155                              &s->ext_host_addr, s->ext_host_port,
 156                              s->in2out.protocol, is_twice_nat_session (s));
 157
 158       nat_ha_sdel (&s->out2in.addr, s->out2in.port, &s->ext_host_addr,
 159                    s->ext_host_port, s->out2in.protocol, s->out2in.fib_index,
 160                    ctx->thread_index);
 161
 162       if (is_twice_nat_session (s))
 163         {
 164           for (i = 0; i < vec_len (sm->twice_nat_addresses); i++)
 165             {
 166               key.protocol = s->in2out.protocol;
 167               key.port = s->ext_host_nat_port;
 168               a = sm->twice_nat_addresses + i;
 169               if (a->addr.as_u32 == s->ext_host_nat_addr.as_u32)
 170                 {
 171                   snat_free_outside_address_and_port (sm->twice_nat_addresses,
 172                                                       ctx->thread_index,
 173                                                       &key);
 174                   break;
 175                 }
 176             }
 177         }
 178
 179       if (snat_is_session_static (s))
 180         goto delete;
 181
 182       snat_free_outside_address_and_port (sm->addresses, ctx->thread_index,
 183                                           &s->out2in);
 184     delete:
 185       nat_ed_session_delete (sm, s, ctx->thread_index, 1);
 186       return 1;
 187     }
 188
 189   return 0;
 190 }
 191 #endif
 192
 193 static snat_session_t *
 194 create_session_for_static_mapping_ed (snat_main_t * sm,
 195                                       vlib_buffer_t * b,
 196                                       snat_session_key_t l_key,
 197                                       snat_session_key_t e_key,
 198                                       vlib_node_runtime_t * node,
 199                                       u32 rx_fib_index,
 200                                       u32 thread_index,
 201                                       twice_nat_type_t twice_nat,
 202                                       lb_nat_type_t lb_nat, f64 now)
 203 {
 204   snat_session_t *s;
 205   ip4_header_t *ip;
 206   udp_header_t *udp;
 207   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 208   clib_bihash_kv_16_8_t kv;
 209   snat_session_key_t eh_key;
 210   nat44_is_idle_session_ctx_t ctx;
 211
 212   if (PREDICT_FALSE
 213       (nat44_ed_maximum_sessions_exceeded (sm, rx_fib_index, thread_index)))
 214     {
 215       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 216       nat_elog_notice ("maximum sessions exceeded");
 217       return 0;
 218     }
 219
 220   s = nat_ed_session_alloc (sm, thread_index, now, e_key.protocol);
 221   if (!s)
 222     {
 223       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_USER_SESS_EXCEEDED];
 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 == NAT_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
 243   /* Add to lookup tables */
 244   make_ed_kv (&e_key.addr, &s->ext_host_addr, ip->protocol,
 245               e_key.fib_index, e_key.port, s->ext_host_port,
 246               s - tsm->sessions, &kv);
 247   ctx.now = now;
 248   ctx.thread_index = thread_index;
 249   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->out2in_ed, &kv,
 250                                                nat44_o2i_ed_is_idle_session_cb,
 251                                                &ctx))
 252     nat_elog_notice ("out2in-ed key add failed");
 253
 254   if (twice_nat == TWICE_NAT || (twice_nat == TWICE_NAT_SELF &&
 255                                  ip->src_address.as_u32 == l_key.addr.as_u32))
 256     {
 257       eh_key.protocol = e_key.protocol;
 258       if (snat_alloc_outside_address_and_port (sm->twice_nat_addresses, 0,
 259                                                thread_index, &eh_key,
 260                                                sm->port_per_thread,
 261                                                tsm->snat_thread_index))
 262         {
 263           b->error = node->errors[NAT_OUT2IN_ED_ERROR_OUT_OF_PORTS];
 264           nat_ed_session_delete (sm, s, thread_index, 1);
 265           if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &kv, 0))
 266             nat_elog_notice ("out2in-ed key del failed");
 267           return 0;
 268         }
 269       s->ext_host_nat_addr.as_u32 = eh_key.addr.as_u32;
 270       s->ext_host_nat_port = eh_key.port;
 271       s->flags |= SNAT_SESSION_FLAG_TWICE_NAT;
 272       make_ed_kv (&l_key.addr, &s->ext_host_nat_addr, ip->protocol,
 273                   l_key.fib_index, l_key.port, s->ext_host_nat_port,
 274                   s - tsm->sessions, &kv);
 275     }
 276   else
 277     {
 278       make_ed_kv (&l_key.addr, &s->ext_host_addr, ip->protocol,
 279                   l_key.fib_index, l_key.port, s->ext_host_port,
 280                   s - tsm->sessions, &kv);
 281     }
 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, 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 (&ip->src_address, &ip->dst_address, ip->protocol,
 318               rx_fib_index, src_port, dst_port, ~0ULL, &kv);
 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   clib_bihash_kv_16_8_t kv, value;
 330   udp_header_t *udp;
 331   snat_session_t *s = 0;
 332   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 333   vlib_main_t *vm = vlib_get_main ();
 334   f64 now = vlib_time_now (vm);
 335   u16 l_port, r_port;
 336
 337   if (ip->protocol == IP_PROTOCOL_ICMP)
 338     {
 339       if (get_icmp_o2i_ed_key
 340           (b, ip, rx_fib_index, ~0ULL, 0, &l_port, &r_port, &kv))
 341         return;
 342     }
 343   else
 344     {
 345       if (ip->protocol == IP_PROTOCOL_UDP || ip->protocol == IP_PROTOCOL_TCP)
 346         {
 347           udp = ip4_next_header (ip);
 348           l_port = udp->dst_port;
 349           r_port = udp->src_port;
 350         }
 351       else
 352         {
 353           l_port = 0;
 354           r_port = 0;
 355         }
 356       make_ed_kv (&ip->dst_address, &ip->src_address, ip->protocol,
 357                   rx_fib_index, l_port, r_port, ~0ULL, &kv);
 358     }
 359
 360   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 361     {
 362       s = pool_elt_at_index (tsm->sessions, value.value);
 363     }
 364   else
 365     {
 366       u32 proto;
 367
 368       if (PREDICT_FALSE
 369           (nat44_ed_maximum_sessions_exceeded
 370            (sm, rx_fib_index, thread_index)))
 371         return;
 372
 373       s = nat_ed_session_alloc (sm, thread_index, now, ip->protocol);
 374       if (!s)
 375         {
 376           nat_elog_warn ("create NAT session failed");
 377           return;
 378         }
 379
 380       proto = ip_proto_to_nat_proto (ip->protocol);
 381
 382       s->ext_host_addr = ip->src_address;
 383       s->ext_host_port = r_port;
 384       s->flags |= SNAT_SESSION_FLAG_FWD_BYPASS;
 385       s->out2in.addr = ip->dst_address;
 386       s->out2in.port = l_port;
 387       s->out2in.protocol = proto;
 388       if (proto == NAT_PROTOCOL_OTHER)
 389         {
 390           s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 391           s->out2in.port = ip->protocol;
 392         }
 393       s->out2in.fib_index = 0;
 394       s->in2out = s->out2in;
 395
 396       kv.value = s - tsm->sessions;
 397       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &kv, 1))
 398         nat_elog_notice ("in2out_ed key add failed");
 399     }
 400
 401   if (ip->protocol == IP_PROTOCOL_TCP)
 402     {
 403       tcp_header_t *tcp = ip4_next_header (ip);
 404       if (nat44_set_tcp_session_state_o2i
 405           (sm, now, s, tcp->flags, tcp->ack_number, tcp->seq_number,
 406            thread_index))
 407         return;
 408     }
 409
 410   /* Accounting */
 411   nat44_session_update_counters (s, now, 0, thread_index);
 412   /* Per-user LRU list maintenance */
 413   nat44_session_update_lru (sm, s, thread_index);
 414 }
 415
 416 static inline void
 417 create_bypass_for_fwd_worker (snat_main_t * sm, vlib_buffer_t * b,
 418                               ip4_header_t * ip, u32 rx_fib_index)
 419 {
 420   ip4_header_t ip_wkr = {
 421     .src_address = ip->dst_address,
 422   };
 423   u32 thread_index = sm->worker_in2out_cb (&ip_wkr, rx_fib_index, 0);
 424
 425   create_bypass_for_fwd (sm, b, ip, rx_fib_index, thread_index);
 426 }
 427
 428 #ifndef CLIB_MARCH_VARIANT
 429 u32
 430 icmp_match_out2in_ed (snat_main_t * sm, vlib_node_runtime_t * node,
 431                       u32 thread_index, vlib_buffer_t * b, ip4_header_t * ip,
 432                       u8 * p_proto, snat_session_key_t * p_value,
 433                       u8 * p_dont_translate, void *d, void *e)
 434 {
 435   u32 next = ~0, sw_if_index, rx_fib_index;
 436   clib_bihash_kv_16_8_t kv, value;
 437   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 438   snat_session_t *s = 0;
 439   u8 dont_translate = 0, is_addr_only, identity_nat;
 440   snat_session_key_t e_key, l_key;
 441   u16 l_port, r_port;
 442   vlib_main_t *vm = vlib_get_main ();
 443
 444   sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
 445   rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 446
 447   if (get_icmp_o2i_ed_key
 448       (b, ip, rx_fib_index, ~0ULL, p_proto, &l_port, &r_port, &kv))
 449     {
 450       b->error = node->errors[NAT_OUT2IN_ED_ERROR_UNSUPPORTED_PROTOCOL];
 451       next = NAT_NEXT_DROP;
 452       goto out;
 453     }
 454
 455   if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv, &value))
 456     {
 457       /* Try to match static mapping */
 458       e_key.addr = ip->dst_address;
 459       e_key.port = l_port;
 460       e_key.protocol = ip_proto_to_nat_proto (ip->protocol);
 461       e_key.fib_index = rx_fib_index;
 462       if (snat_static_mapping_match
 463           (sm, e_key, &l_key, 1, &is_addr_only, 0, 0, 0, &identity_nat))
 464         {
 465           if (!sm->forwarding_enabled)
 466             {
 467               /* Don't NAT packet aimed at the intfc address */
 468               if (PREDICT_FALSE (is_interface_addr (sm, node, sw_if_index,
 469                                                     ip->dst_address.as_u32)))
 470                 {
 471                   dont_translate = 1;
 472                   goto out;
 473                 }
 474               b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 475               next = NAT_NEXT_DROP;
 476               goto out;
 477             }
 478           else
 479             {
 480               dont_translate = 1;
 481               if (next_src_nat (sm, ip, l_port, r_port,
 482                                 thread_index, rx_fib_index))
 483                 {
 484                   next = NAT_NEXT_IN2OUT_ED_FAST_PATH;
 485                   goto out;
 486                 }
 487               if (sm->num_workers > 1)
 488                 create_bypass_for_fwd_worker (sm, b, ip, rx_fib_index);
 489               else
 490                 create_bypass_for_fwd (sm, b, ip, rx_fib_index, thread_index);
 491               goto out;
 492             }
 493         }
 494
 495       if (PREDICT_FALSE
 496           (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 497            ICMP4_echo_reply
 498            && (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 499                ICMP4_echo_request || !is_addr_only)))
 500         {
 501           b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 502           next = NAT_NEXT_DROP;
 503           goto out;
 504         }
 505
 506       if (PREDICT_FALSE (identity_nat))
 507         {
 508           dont_translate = 1;
 509           goto out;
 510         }
 511
 512       /* Create session initiated by host from external network */
 513       s = create_session_for_static_mapping_ed (sm, b, l_key, e_key, node,
 514                                                 rx_fib_index, thread_index, 0,
 515                                                 0, vlib_time_now (vm));
 516
 517       if (!s)
 518         {
 519           next = NAT_NEXT_DROP;
 520           goto out;
 521         }
 522     }
 523   else
 524     {
 525       if (PREDICT_FALSE
 526           (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 527            ICMP4_echo_reply
 528            && vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 529            ICMP4_echo_request
 530            && !icmp_type_is_error_message (vnet_buffer (b)->ip.
 531                                            reass.icmp_type_or_tcp_flags)))
 532         {
 533           b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 534           next = NAT_NEXT_DROP;
 535           goto out;
 536         }
 537
 538       s = pool_elt_at_index (tsm->sessions, value.value);
 539     }
 540 out:
 541   if (s)
 542     *p_value = s->in2out;
 543   *p_dont_translate = dont_translate;
 544   if (d)
 545     *(snat_session_t **) d = s;
 546   return next;
 547 }
 548 #endif
 549
 550 static snat_session_t *
 551 nat44_ed_out2in_unknown_proto (snat_main_t * sm,
 552                                vlib_buffer_t * b,
 553                                ip4_header_t * ip,
 554                                u32 rx_fib_index,
 555                                u32 thread_index,
 556                                f64 now,
 557                                vlib_main_t * vm, vlib_node_runtime_t * node)
 558 {
 559   clib_bihash_kv_8_8_t kv, value;
 560   clib_bihash_kv_16_8_t s_kv, s_value;
 561   snat_static_mapping_t *m;
 562   u32 old_addr, new_addr;
 563   ip_csum_t sum;
 564   snat_session_t *s;
 565   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 566
 567   old_addr = ip->dst_address.as_u32;
 568
 569   make_ed_kv (&ip->dst_address, &ip->src_address, ip->protocol, rx_fib_index,
 570               0, 0, ~0ULL, &s_kv);
 571
 572   if (!clib_bihash_search_16_8 (&tsm->out2in_ed, &s_kv, &s_value))
 573     {
 574       s = pool_elt_at_index (tsm->sessions, s_value.value);
 575       new_addr = ip->dst_address.as_u32 = s->in2out.addr.as_u32;
 576     }
 577   else
 578     {
 579       if (PREDICT_FALSE
 580           (nat44_ed_maximum_sessions_exceeded
 581            (sm, rx_fib_index, thread_index)))
 582         {
 583           b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 584           nat_elog_notice ("maximum sessions exceeded");
 585           return 0;
 586         }
 587
 588       make_sm_kv (&kv, &ip->dst_address, 0, 0, 0);
 589       if (clib_bihash_search_8_8
 590           (&sm->static_mapping_by_external, &kv, &value))
 591         {
 592           b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 593           return 0;
 594         }
 595
 596       m = pool_elt_at_index (sm->static_mappings, value.value);
 597
 598       new_addr = ip->dst_address.as_u32 = m->local_addr.as_u32;
 599
 600       /* Create a new session */
 601       s = nat_ed_session_alloc (sm, thread_index, now, ip->protocol);
 602       if (!s)
 603         {
 604           b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_USER_SESS_EXCEEDED];
 605           nat_elog_warn ("create NAT session failed");
 606           return 0;
 607         }
 608
 609       s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 610       s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 611       s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 612       s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 613       s->out2in.addr.as_u32 = old_addr;
 614       s->out2in.fib_index = rx_fib_index;
 615       s->in2out.addr.as_u32 = new_addr;
 616       s->in2out.fib_index = m->fib_index;
 617       s->in2out.port = s->out2in.port = ip->protocol;
 618
 619       /* Add to lookup tables */
 620       s_kv.value = s - tsm->sessions;
 621       if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &s_kv, 1))
 622         nat_elog_notice ("out2in key add failed");
 623
 624       make_ed_kv (&ip->dst_address, &ip->src_address, ip->protocol,
 625                   m->fib_index, 0, 0, s - tsm->sessions, &s_kv);
 626       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &s_kv, 1))
 627         nat_elog_notice ("in2out key add failed");
 628     }
 629
 630   /* Update IP checksum */
 631   sum = ip->checksum;
 632   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
 633   ip->checksum = ip_csum_fold (sum);
 634
 635   vnet_buffer (b)->sw_if_index[VLIB_TX] = s->in2out.fib_index;
 636
 637   /* Accounting */
 638   nat44_session_update_counters (s, now, vlib_buffer_length_in_chain (vm, b),
 639                                  thread_index);
 640   /* Per-user LRU list maintenance */
 641   nat44_session_update_lru (sm, s, thread_index);
 642
 643   return s;
 644 }
 645
 646 static inline uword
 647 nat44_ed_out2in_fast_path_node_fn_inline (vlib_main_t * vm,
 648                                           vlib_node_runtime_t * node,
 649                                           vlib_frame_t * frame)
 650 {
 651   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
 652   nat_next_t next_index;
 653   snat_main_t *sm = &snat_main;
 654   f64 now = vlib_time_now (vm);
 655   u32 thread_index = vm->thread_index;
 656   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 657   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 658     0, fragments = 0;
 659
 660   stats_node_index = sm->ed_out2in_node_index;
 661
 662   from = vlib_frame_vector_args (frame);
 663   n_left_from = frame->n_vectors;
 664   next_index = node->cached_next_index;
 665
 666   while (n_left_from > 0)
 667     {
 668       u32 n_left_to_next;
 669
 670       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 671
 672       while (n_left_from > 0 && n_left_to_next > 0)
 673         {
 674           u32 bi0;
 675           vlib_buffer_t *b0;
 676           u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
 677             new_addr0;
 678           u16 old_port0, new_port0;
 679           ip4_header_t *ip0;
 680           udp_header_t *udp0;
 681           tcp_header_t *tcp0;
 682           snat_session_t *s0 = 0;
 683           clib_bihash_kv_16_8_t kv0, value0;
 684           ip_csum_t sum0;
 685
 686           /* speculatively enqueue b0 to the current next frame */
 687           bi0 = from[0];
 688           to_next[0] = bi0;
 689           from += 1;
 690           to_next += 1;
 691           n_left_from -= 1;
 692           n_left_to_next -= 1;
 693
 694           b0 = vlib_get_buffer (vm, bi0);
 695           next0 = vnet_buffer2 (b0)->nat.arc_next;
 696
 697           vnet_buffer (b0)->snat.flags = 0;
 698           ip0 = vlib_buffer_get_current (b0);
 699
 700           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 701           rx_fib_index0 =
 702             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 703                                                  sw_if_index0);
 704
 705           if (PREDICT_FALSE (ip0->ttl == 1))
 706             {
 707               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 708               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 709                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 710                                            0);
 711               next0 = NAT_NEXT_ICMP_ERROR;
 712               goto trace0;
 713             }
 714
 715           udp0 = ip4_next_header (ip0);
 716           tcp0 = (tcp_header_t *) udp0;
 717           proto0 = ip_proto_to_nat_proto (ip0->protocol);
 718
 719           if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
 720             {
 721               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 722               goto trace0;
 723             }
 724
 725           if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
 726             {
 727               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 728               goto trace0;
 729             }
 730
 731           make_ed_kv (&ip0->dst_address, &ip0->src_address,
 732                       ip0->protocol, rx_fib_index0,
 733                       vnet_buffer (b0)->ip.reass.l4_dst_port,
 734                       vnet_buffer (b0)->ip.reass.l4_src_port, ~0ULL, &kv0);
 735
 736           if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv0, &value0))
 737             {
 738               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 739               goto trace0;
 740             }
 741           s0 = pool_elt_at_index (tsm->sessions, value0.value);
 742
 743           if (s0->tcp_closed_timestamp)
 744             {
 745               if (now >= s0->tcp_closed_timestamp)
 746                 {
 747                   // session is closed, go slow path
 748                   next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 749                 }
 750               else
 751                 {
 752                   // session in transitory timeout, drop
 753                   b0->error = node->errors[NAT_OUT2IN_ED_ERROR_TCP_CLOSED];
 754                   next0 = NAT_NEXT_DROP;
 755                 }
 756               goto trace0;
 757             }
 758
 759           // drop if session expired
 760           u64 sess_timeout_time;
 761           sess_timeout_time = s0->last_heard +
 762             (f64) nat44_session_get_timeout (sm, s0);
 763           if (now >= sess_timeout_time)
 764             {
 765               // session is closed, go slow path
 766               nat_free_session_data (sm, s0, thread_index, 0);
 767               nat_ed_session_delete (sm, s0, thread_index, 1);
 768               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 769               goto trace0;
 770             }
 771           //
 772
 773           old_addr0 = ip0->dst_address.as_u32;
 774           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
 775           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
 776
 777           sum0 = ip0->checksum;
 778           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 779                                  dst_address);
 780           if (PREDICT_FALSE (is_twice_nat_session (s0)))
 781             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 782                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
 783                                    src_address);
 784           ip0->checksum = ip_csum_fold (sum0);
 785
 786           old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
 787
 788           if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
 789             {
 790               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 791                 {
 792                   new_port0 = udp0->dst_port = s0->in2out.port;
 793                   sum0 = tcp0->checksum;
 794                   sum0 =
 795                     ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 796                                     dst_address);
 797                   sum0 =
 798                     ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 799                                     length);
 800                   if (is_twice_nat_session (s0))
 801                     {
 802                       sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 803                                              s0->ext_host_nat_addr.as_u32,
 804                                              ip4_header_t, dst_address);
 805                       sum0 =
 806                         ip_csum_update (sum0,
 807                                         vnet_buffer (b0)->ip.
 808                                         reass.l4_src_port,
 809                                         s0->ext_host_nat_port, ip4_header_t,
 810                                         length);
 811                       tcp0->src_port = s0->ext_host_nat_port;
 812                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 813                     }
 814                   tcp0->checksum = ip_csum_fold (sum0);
 815                 }
 816               tcp_packets++;
 817               if (nat44_set_tcp_session_state_o2i
 818                   (sm, now, s0,
 819                    vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags,
 820                    vnet_buffer (b0)->ip.reass.tcp_ack_number,
 821                    vnet_buffer (b0)->ip.reass.tcp_seq_number, thread_index))
 822                 goto trace0;
 823             }
 824           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
 825                    && udp0->checksum)
 826             {
 827               new_port0 = udp0->dst_port = s0->in2out.port;
 828               sum0 = udp0->checksum;
 829               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 830                                      dst_address);
 831               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 832                                      length);
 833               if (PREDICT_FALSE (is_twice_nat_session (s0)))
 834                 {
 835                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 836                                          s0->ext_host_nat_addr.as_u32,
 837                                          ip4_header_t, dst_address);
 838                   sum0 =
 839                     ip_csum_update (sum0,
 840                                     vnet_buffer (b0)->ip.reass.l4_src_port,
 841                                     s0->ext_host_nat_port, ip4_header_t,
 842                                     length);
 843                   udp0->src_port = s0->ext_host_nat_port;
 844                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 845                 }
 846               udp0->checksum = ip_csum_fold (sum0);
 847               udp_packets++;
 848             }
 849           else
 850             {
 851               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 852                 {
 853                   new_port0 = udp0->dst_port = s0->in2out.port;
 854                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
 855                     {
 856                       udp0->src_port = s0->ext_host_nat_port;
 857                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 858                     }
 859                 }
 860               udp_packets++;
 861             }
 862
 863           /* Accounting */
 864           nat44_session_update_counters (s0, now,
 865                                          vlib_buffer_length_in_chain (vm, b0),
 866                                          thread_index);
 867           /* Per-user LRU list maintenance */
 868           nat44_session_update_lru (sm, s0, thread_index);
 869
 870         trace0:
 871           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 872                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 873             {
 874               nat44_ed_out2in_trace_t *t =
 875                 vlib_add_trace (vm, node, b0, sizeof (*t));
 876               t->sw_if_index = sw_if_index0;
 877               t->next_index = next0;
 878               t->is_slow_path = 0;
 879
 880               if (s0)
 881                 t->session_index = s0 - tsm->sessions;
 882               else
 883                 t->session_index = ~0;
 884             }
 885
 886           pkts_processed += next0 == vnet_buffer2 (b0)->nat.arc_next;
 887           /* verify speculative enqueue, maybe switch current next frame */
 888           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 889                                            to_next, n_left_to_next,
 890                                            bi0, next0);
 891         }
 892
 893       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 894     }
 895
 896   vlib_node_increment_counter (vm, stats_node_index,
 897                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
 898                                pkts_processed);
 899   vlib_node_increment_counter (vm, stats_node_index,
 900                                NAT_OUT2IN_ED_ERROR_TCP_PACKETS, tcp_packets);
 901   vlib_node_increment_counter (vm, stats_node_index,
 902                                NAT_OUT2IN_ED_ERROR_UDP_PACKETS, udp_packets);
 903   vlib_node_increment_counter (vm, stats_node_index,
 904                                NAT_OUT2IN_ED_ERROR_ICMP_PACKETS,
 905                                icmp_packets);
 906   vlib_node_increment_counter (vm, stats_node_index,
 907                                NAT_OUT2IN_ED_ERROR_OTHER_PACKETS,
 908                                other_packets);
 909   vlib_node_increment_counter (vm, stats_node_index,
 910                                NAT_OUT2IN_ED_ERROR_FRAGMENTS, fragments);
 911   return frame->n_vectors;
 912 }
 913
 914 static inline uword
 915 nat44_ed_out2in_slow_path_node_fn_inline (vlib_main_t * vm,
 916                                           vlib_node_runtime_t * node,
 917                                           vlib_frame_t * frame)
 918 {
 919   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
 920   nat_next_t next_index;
 921   snat_main_t *sm = &snat_main;
 922   // HERE
 923   f64 now = vlib_time_now (vm);
 924   u32 thread_index = vm->thread_index;
 925   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 926   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 927     0, fragments = 0;
 928
 929   stats_node_index = sm->ed_out2in_slowpath_node_index;
 930
 931   from = vlib_frame_vector_args (frame);
 932   n_left_from = frame->n_vectors;
 933   next_index = node->cached_next_index;
 934
 935   while (n_left_from > 0)
 936     {
 937       u32 n_left_to_next;
 938
 939       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 940
 941       while (n_left_from > 0 && n_left_to_next > 0)
 942         {
 943           u32 bi0;
 944           vlib_buffer_t *b0;
 945           u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
 946             new_addr0;
 947           u16 old_port0, new_port0;
 948           ip4_header_t *ip0;
 949           udp_header_t *udp0;
 950           tcp_header_t *tcp0;
 951           icmp46_header_t *icmp0;
 952           snat_session_t *s0 = 0;
 953           clib_bihash_kv_16_8_t kv0, value0;
 954           ip_csum_t sum0;
 955           snat_session_key_t e_key0, l_key0;
 956           lb_nat_type_t lb_nat0;
 957           twice_nat_type_t twice_nat0;
 958           u8 identity_nat0;
 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           next0 = vnet_buffer2 (b0)->nat.arc_next;
 970
 971           vnet_buffer (b0)->snat.flags = 0;
 972           ip0 = vlib_buffer_get_current (b0);
 973
 974           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 975           rx_fib_index0 =
 976             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 977                                                  sw_if_index0);
 978
 979           if (PREDICT_FALSE (ip0->ttl == 1))
 980             {
 981               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 982               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 983                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 984                                            0);
 985               next0 = NAT_NEXT_ICMP_ERROR;
 986               goto trace0;
 987             }
 988
 989           udp0 = ip4_next_header (ip0);
 990           tcp0 = (tcp_header_t *) udp0;
 991           icmp0 = (icmp46_header_t *) udp0;
 992           proto0 = ip_proto_to_nat_proto (ip0->protocol);
 993
 994           if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
 995             {
 996               s0 =
 997                 nat44_ed_out2in_unknown_proto (sm, b0, ip0, rx_fib_index0,
 998                                                thread_index, now, vm, node);
 999               if (!sm->forwarding_enabled)
1000                 {
1001                   if (!s0)
1002                     next0 = NAT_NEXT_DROP;
1003                 }
1004               other_packets++;
1005               goto trace0;
1006             }
1007
1008           if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
1009             {
1010               next0 = icmp_out2in_ed_slow_path
1011                 (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1012                  next0, now, thread_index, &s0);
1013               icmp_packets++;
1014               goto trace0;
1015             }
1016
1017           make_ed_kv (&ip0->dst_address, &ip0->src_address,
1018                       ip0->protocol, rx_fib_index0,
1019                       vnet_buffer (b0)->ip.reass.l4_dst_port,
1020                       vnet_buffer (b0)->ip.reass.l4_src_port, ~0ULL, &kv0);
1021
1022           s0 = NULL;
1023           if (!clib_bihash_search_16_8 (&tsm->out2in_ed, &kv0, &value0))
1024             {
1025               s0 = pool_elt_at_index (tsm->sessions, value0.value);
1026
1027               if (s0->tcp_closed_timestamp && now >= s0->tcp_closed_timestamp)
1028                 {
1029                   nat_free_session_data (sm, s0, thread_index, 0);
1030                   nat_ed_session_delete (sm, s0, thread_index, 1);
1031                   s0 = NULL;
1032                 }
1033             }
1034
1035           if (!s0)
1036             {
1037               /* Try to match static mapping by external address and port,
1038                  destination address and port in packet */
1039               e_key0.addr = ip0->dst_address;
1040               e_key0.port = vnet_buffer (b0)->ip.reass.l4_dst_port;
1041               e_key0.protocol = proto0;
1042               e_key0.fib_index = rx_fib_index0;
1043
1044               if (snat_static_mapping_match (sm, e_key0, &l_key0, 1, 0,
1045                                              &twice_nat0, &lb_nat0,
1046                                              &ip0->src_address,
1047                                              &identity_nat0))
1048                 {
1049                   /*
1050                    * Send DHCP packets to the ipv4 stack, or we won't
1051                    * be able to use dhcp client on the outside interface
1052                    */
1053                   if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_UDP
1054                                      && (vnet_buffer (b0)->ip.
1055                                          reass.l4_dst_port ==
1056                                          clib_host_to_net_u16
1057                                          (UDP_DST_PORT_dhcp_to_client))))
1058                     {
1059                       goto trace0;
1060                     }
1061
1062                   if (!sm->forwarding_enabled)
1063                     {
1064                       b0->error =
1065                         node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
1066                       next0 = NAT_NEXT_DROP;
1067                     }
1068                   else
1069                     {
1070                       if (next_src_nat
1071                           (sm, ip0, vnet_buffer (b0)->ip.reass.l4_src_port,
1072                            vnet_buffer (b0)->ip.reass.l4_dst_port,
1073                            thread_index, rx_fib_index0))
1074                         {
1075                           next0 = NAT_NEXT_IN2OUT_ED_FAST_PATH;
1076                           goto trace0;
1077                         }
1078                       if (sm->num_workers > 1)
1079                         create_bypass_for_fwd_worker (sm, b0, ip0,
1080                                                       rx_fib_index0);
1081                       else
1082                         create_bypass_for_fwd (sm, b0, ip0, rx_fib_index0,
1083                                                thread_index);
1084                     }
1085                   goto trace0;
1086                 }
1087
1088               if (PREDICT_FALSE (identity_nat0))
1089                 goto trace0;
1090
1091               if ((proto0 == NAT_PROTOCOL_TCP)
1092                   && !tcp_flags_is_init (vnet_buffer (b0)->ip.
1093                                          reass.icmp_type_or_tcp_flags))
1094                 {
1095                   b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
1096                   next0 = NAT_NEXT_DROP;
1097                   goto trace0;
1098                 }
1099
1100               /* Create session initiated by host from external network */
1101               s0 = create_session_for_static_mapping_ed (sm, b0, l_key0,
1102                                                          e_key0, node,
1103                                                          rx_fib_index0,
1104                                                          thread_index,
1105                                                          twice_nat0,
1106                                                          lb_nat0, now);
1107               if (!s0)
1108                 {
1109                   next0 = NAT_NEXT_DROP;
1110                   goto trace0;
1111                 }
1112             }
1113
1114           old_addr0 = ip0->dst_address.as_u32;
1115           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
1116           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
1117
1118           sum0 = ip0->checksum;
1119           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1120                                  dst_address);
1121           if (PREDICT_FALSE (is_twice_nat_session (s0)))
1122             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1123                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
1124                                    src_address);
1125           ip0->checksum = ip_csum_fold (sum0);
1126
1127           old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
1128
1129           if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
1130             {
1131               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1132                 {
1133                   new_port0 = udp0->dst_port = s0->in2out.port;
1134                   sum0 = tcp0->checksum;
1135                   sum0 =
1136                     ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1137                                     dst_address);
1138                   sum0 =
1139                     ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1140                                     length);
1141                   if (is_twice_nat_session (s0))
1142                     {
1143                       sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1144                                              s0->ext_host_nat_addr.as_u32,
1145                                              ip4_header_t, dst_address);
1146                       sum0 =
1147                         ip_csum_update (sum0,
1148                                         vnet_buffer (b0)->ip.
1149                                         reass.l4_src_port,
1150                                         s0->ext_host_nat_port, ip4_header_t,
1151                                         length);
1152                       tcp0->src_port = s0->ext_host_nat_port;
1153                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1154                     }
1155                   tcp0->checksum = ip_csum_fold (sum0);
1156                 }
1157               tcp_packets++;
1158               if (nat44_set_tcp_session_state_o2i
1159                   (sm, now, s0,
1160                    vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags,
1161                    vnet_buffer (b0)->ip.reass.tcp_ack_number,
1162                    vnet_buffer (b0)->ip.reass.tcp_seq_number, thread_index))
1163                 goto trace0;
1164             }
1165           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
1166                    && udp0->checksum)
1167             {
1168               new_port0 = udp0->dst_port = s0->in2out.port;
1169               sum0 = udp0->checksum;
1170               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1171                                      dst_address);
1172               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1173                                      length);
1174               if (PREDICT_FALSE (is_twice_nat_session (s0)))
1175                 {
1176                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1177                                          s0->ext_host_nat_addr.as_u32,
1178                                          ip4_header_t, dst_address);
1179                   sum0 =
1180                     ip_csum_update (sum0,
1181                                     vnet_buffer (b0)->ip.reass.l4_src_port,
1182                                     s0->ext_host_nat_port, ip4_header_t,
1183                                     length);
1184                   udp0->src_port = s0->ext_host_nat_port;
1185                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1186                 }
1187               udp0->checksum = ip_csum_fold (sum0);
1188               udp_packets++;
1189             }
1190           else
1191             {
1192               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1193                 {
1194                   new_port0 = udp0->dst_port = s0->in2out.port;
1195                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
1196                     {
1197                       udp0->src_port = s0->ext_host_nat_port;
1198                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1199                     }
1200                 }
1201               udp_packets++;
1202             }
1203
1204           /* Accounting */
1205           nat44_session_update_counters (s0, now,
1206                                          vlib_buffer_length_in_chain (vm, b0),
1207                                          thread_index);
1208           /* Per-user LRU list maintenance */
1209           nat44_session_update_lru (sm, s0, thread_index);
1210
1211         trace0:
1212           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1213                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1214             {
1215               nat44_ed_out2in_trace_t *t =
1216                 vlib_add_trace (vm, node, b0, sizeof (*t));
1217               t->sw_if_index = sw_if_index0;
1218               t->next_index = next0;
1219               t->is_slow_path = 1;
1220
1221               if (s0)
1222                 t->session_index = s0 - tsm->sessions;
1223               else
1224                 t->session_index = ~0;
1225             }
1226
1227           pkts_processed += next0 == vnet_buffer2 (b0)->nat.arc_next;
1228           /* verify speculative enqueue, maybe switch current next frame */
1229           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1230                                            to_next, n_left_to_next,
1231                                            bi0, next0);
1232         }
1233
1234       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1235     }
1236
1237   vlib_node_increment_counter (vm, stats_node_index,
1238                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
1239                                pkts_processed);
1240   vlib_node_increment_counter (vm, stats_node_index,
1241                                NAT_OUT2IN_ED_ERROR_TCP_PACKETS, tcp_packets);
1242   vlib_node_increment_counter (vm, stats_node_index,
1243                                NAT_OUT2IN_ED_ERROR_UDP_PACKETS, udp_packets);
1244   vlib_node_increment_counter (vm, stats_node_index,
1245                                NAT_OUT2IN_ED_ERROR_ICMP_PACKETS,
1246                                icmp_packets);
1247   vlib_node_increment_counter (vm, stats_node_index,
1248                                NAT_OUT2IN_ED_ERROR_OTHER_PACKETS,
1249                                other_packets);
1250   vlib_node_increment_counter (vm, stats_node_index,
1251                                NAT_OUT2IN_ED_ERROR_FRAGMENTS, fragments);
1252   return frame->n_vectors;
1253 }
1254
1255 VLIB_NODE_FN (nat44_ed_out2in_node) (vlib_main_t * vm,
1256                                      vlib_node_runtime_t * node,
1257                                      vlib_frame_t * frame)
1258 {
1259   return nat44_ed_out2in_fast_path_node_fn_inline (vm, node, frame);
1260 }
1261
1262 /* *INDENT-OFF* */
1263 VLIB_REGISTER_NODE (nat44_ed_out2in_node) = {
1264   .name = "nat44-ed-out2in",
1265   .vector_size = sizeof (u32),
1266   .sibling_of = "nat-default",
1267   .format_trace = format_nat44_ed_out2in_trace,
1268   .type = VLIB_NODE_TYPE_INTERNAL,
1269   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1270   .error_strings = nat_out2in_ed_error_strings,
1271   .runtime_data_bytes = sizeof (snat_runtime_t),
1272 };
1273 /* *INDENT-ON* */
1274
1275 VLIB_NODE_FN (nat44_ed_out2in_slowpath_node) (vlib_main_t * vm,
1276                                               vlib_node_runtime_t * node,
1277                                               vlib_frame_t * frame)
1278 {
1279   return nat44_ed_out2in_slow_path_node_fn_inline (vm, node, frame);
1280 }
1281
1282 /* *INDENT-OFF* */
1283 VLIB_REGISTER_NODE (nat44_ed_out2in_slowpath_node) = {
1284   .name = "nat44-ed-out2in-slowpath",
1285   .vector_size = sizeof (u32),
1286   .sibling_of = "nat-default",
1287   .format_trace = format_nat44_ed_out2in_trace,
1288   .type = VLIB_NODE_TYPE_INTERNAL,
1289   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1290   .error_strings = nat_out2in_ed_error_strings,
1291   .runtime_data_bytes = sizeof (snat_runtime_t),
1292 };
1293 /* *INDENT-ON* */
1294
1295 static u8 *
1296 format_nat_pre_trace (u8 * s, va_list * args)
1297 {
1298   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1299   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1300   nat_pre_trace_t *t = va_arg (*args, nat_pre_trace_t *);
1301   return format (s, "out2in next_index %d arc_next_index %d", t->next_index,
1302                  t->arc_next_index);
1303 }
1304
1305 VLIB_NODE_FN (nat_pre_out2in_node) (vlib_main_t * vm,
1306                                     vlib_node_runtime_t * node,
1307                                     vlib_frame_t * frame)
1308 {
1309   return nat_pre_node_fn_inline (vm, node, frame,
1310                                  NAT_NEXT_OUT2IN_ED_FAST_PATH);
1311 }
1312
1313 /* *INDENT-OFF* */
1314 VLIB_REGISTER_NODE (nat_pre_out2in_node) = {
1315   .name = "nat-pre-out2in",
1316   .vector_size = sizeof (u32),
1317   .sibling_of = "nat-default",
1318   .format_trace = format_nat_pre_trace,
1319   .type = VLIB_NODE_TYPE_INTERNAL,
1320   .n_errors = 0,
1321  };
1322 /* *INDENT-ON* */
1323
1324 /*
1325  * fd.io coding-style-patch-verification: ON
1326  *
1327  * Local Variables:
1328  * eval: (c-set-style "gnu")
1329  * End:
1330  */