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, ~0, ~0,
 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, thread_index,
 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 (&sm->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 (&sm->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                   thread_index, 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, thread_index,
 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, ~0, ~0, &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, ~0, ~0, 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, ~0, ~0, &kv);
 358     }
 359
 360   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 361     {
 362       ASSERT (thread_index == ed_value_get_thread_index (&value));
 363       s =
 364         pool_elt_at_index (tsm->sessions,
 365                            ed_value_get_session_index (&value));
 366     }
 367   else
 368     {
 369       u32 proto;
 370
 371       if (PREDICT_FALSE
 372           (nat44_ed_maximum_sessions_exceeded
 373            (sm, rx_fib_index, thread_index)))
 374         return;
 375
 376       s = nat_ed_session_alloc (sm, thread_index, now, ip->protocol);
 377       if (!s)
 378         {
 379           nat_elog_warn ("create NAT session failed");
 380           return;
 381         }
 382
 383       proto = ip_proto_to_nat_proto (ip->protocol);
 384
 385       s->ext_host_addr = ip->src_address;
 386       s->ext_host_port = r_port;
 387       s->flags |= SNAT_SESSION_FLAG_FWD_BYPASS;
 388       s->out2in.addr = ip->dst_address;
 389       s->out2in.port = l_port;
 390       s->out2in.protocol = proto;
 391       if (proto == NAT_PROTOCOL_OTHER)
 392         {
 393           s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 394           s->out2in.port = ip->protocol;
 395         }
 396       s->out2in.fib_index = 0;
 397       s->in2out = s->out2in;
 398
 399       kv.value = s - tsm->sessions;
 400       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &kv, 1))
 401         nat_elog_notice ("in2out_ed key add failed");
 402     }
 403
 404   if (ip->protocol == IP_PROTOCOL_TCP)
 405     {
 406       tcp_header_t *tcp = ip4_next_header (ip);
 407       if (nat44_set_tcp_session_state_o2i
 408           (sm, now, s, tcp->flags, tcp->ack_number, tcp->seq_number,
 409            thread_index))
 410         return;
 411     }
 412
 413   /* Accounting */
 414   nat44_session_update_counters (s, now, 0, thread_index);
 415   /* Per-user LRU list maintenance */
 416   nat44_session_update_lru (sm, s, thread_index);
 417 }
 418
 419 static inline void
 420 create_bypass_for_fwd_worker (snat_main_t * sm, vlib_buffer_t * b,
 421                               ip4_header_t * ip, u32 rx_fib_index)
 422 {
 423   ip4_header_t ip_wkr = {
 424     .src_address = ip->dst_address,
 425   };
 426   u32 thread_index = sm->worker_in2out_cb (&ip_wkr, rx_fib_index, 0);
 427
 428   create_bypass_for_fwd (sm, b, ip, rx_fib_index, thread_index);
 429 }
 430
 431 #ifndef CLIB_MARCH_VARIANT
 432 u32
 433 icmp_match_out2in_ed (snat_main_t * sm, vlib_node_runtime_t * node,
 434                       u32 thread_index, vlib_buffer_t * b, ip4_header_t * ip,
 435                       u8 * p_proto, snat_session_key_t * p_value,
 436                       u8 * p_dont_translate, void *d, void *e)
 437 {
 438   u32 next = ~0, sw_if_index, rx_fib_index;
 439   clib_bihash_kv_16_8_t kv, value;
 440   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 441   snat_session_t *s = 0;
 442   u8 dont_translate = 0, is_addr_only, identity_nat;
 443   snat_session_key_t e_key, l_key;
 444   u16 l_port, r_port;
 445   vlib_main_t *vm = vlib_get_main ();
 446
 447   sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
 448   rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 449
 450   if (get_icmp_o2i_ed_key
 451       (b, ip, rx_fib_index, ~0, ~0, p_proto, &l_port, &r_port, &kv))
 452     {
 453       b->error = node->errors[NAT_OUT2IN_ED_ERROR_UNSUPPORTED_PROTOCOL];
 454       next = NAT_NEXT_DROP;
 455       goto out;
 456     }
 457
 458   if (clib_bihash_search_16_8 (&sm->out2in_ed, &kv, &value))
 459     {
 460       /* Try to match static mapping */
 461       e_key.addr = ip->dst_address;
 462       e_key.port = l_port;
 463       e_key.protocol = ip_proto_to_nat_proto (ip->protocol);
 464       e_key.fib_index = rx_fib_index;
 465       if (snat_static_mapping_match
 466           (sm, e_key, &l_key, 1, &is_addr_only, 0, 0, 0, &identity_nat))
 467         {
 468           if (!sm->forwarding_enabled)
 469             {
 470               /* Don't NAT packet aimed at the intfc address */
 471               if (PREDICT_FALSE (is_interface_addr (sm, node, sw_if_index,
 472                                                     ip->dst_address.as_u32)))
 473                 {
 474                   dont_translate = 1;
 475                   goto out;
 476                 }
 477               b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 478               next = NAT_NEXT_DROP;
 479               goto out;
 480             }
 481           else
 482             {
 483               dont_translate = 1;
 484               if (next_src_nat (sm, ip, l_port, r_port,
 485                                 thread_index, rx_fib_index))
 486                 {
 487                   next = NAT_NEXT_IN2OUT_ED_FAST_PATH;
 488                   goto out;
 489                 }
 490               if (sm->num_workers > 1)
 491                 create_bypass_for_fwd_worker (sm, b, ip, rx_fib_index);
 492               else
 493                 create_bypass_for_fwd (sm, b, ip, rx_fib_index, thread_index);
 494               goto out;
 495             }
 496         }
 497
 498       if (PREDICT_FALSE
 499           (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 500            ICMP4_echo_reply
 501            && (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 502                ICMP4_echo_request || !is_addr_only)))
 503         {
 504           b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 505           next = NAT_NEXT_DROP;
 506           goto out;
 507         }
 508
 509       if (PREDICT_FALSE (identity_nat))
 510         {
 511           dont_translate = 1;
 512           goto out;
 513         }
 514
 515       /* Create session initiated by host from external network */
 516       s = create_session_for_static_mapping_ed (sm, b, l_key, e_key, node,
 517                                                 rx_fib_index, thread_index, 0,
 518                                                 0, vlib_time_now (vm));
 519
 520       if (!s)
 521         {
 522           next = NAT_NEXT_DROP;
 523           goto out;
 524         }
 525     }
 526   else
 527     {
 528       if (PREDICT_FALSE
 529           (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 530            ICMP4_echo_reply
 531            && vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 532            ICMP4_echo_request
 533            && !icmp_type_is_error_message (vnet_buffer (b)->ip.
 534                                            reass.icmp_type_or_tcp_flags)))
 535         {
 536           b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 537           next = NAT_NEXT_DROP;
 538           goto out;
 539         }
 540
 541       ASSERT (thread_index == ed_value_get_thread_index (&value));
 542       s =
 543         pool_elt_at_index (tsm->sessions,
 544                            ed_value_get_session_index (&value));
 545     }
 546 out:
 547   if (s)
 548     *p_value = s->in2out;
 549   *p_dont_translate = dont_translate;
 550   if (d)
 551     *(snat_session_t **) d = s;
 552   return next;
 553 }
 554 #endif
 555
 556 static snat_session_t *
 557 nat44_ed_out2in_unknown_proto (snat_main_t * sm,
 558                                vlib_buffer_t * b,
 559                                ip4_header_t * ip,
 560                                u32 rx_fib_index,
 561                                u32 thread_index,
 562                                f64 now,
 563                                vlib_main_t * vm, vlib_node_runtime_t * node)
 564 {
 565   clib_bihash_kv_8_8_t kv, value;
 566   clib_bihash_kv_16_8_t s_kv, s_value;
 567   snat_static_mapping_t *m;
 568   u32 old_addr, new_addr;
 569   ip_csum_t sum;
 570   snat_session_t *s;
 571   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 572
 573   old_addr = ip->dst_address.as_u32;
 574
 575   make_ed_kv (&ip->dst_address, &ip->src_address, ip->protocol, rx_fib_index,
 576               0, 0, ~0, ~0, &s_kv);
 577
 578   if (!clib_bihash_search_16_8 (&sm->out2in_ed, &s_kv, &s_value))
 579     {
 580       ASSERT (thread_index == ed_value_get_thread_index (&s_value));
 581       s =
 582         pool_elt_at_index (tsm->sessions,
 583                            ed_value_get_session_index (&s_value));
 584       new_addr = ip->dst_address.as_u32 = s->in2out.addr.as_u32;
 585     }
 586   else
 587     {
 588       if (PREDICT_FALSE
 589           (nat44_ed_maximum_sessions_exceeded
 590            (sm, rx_fib_index, thread_index)))
 591         {
 592           b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 593           nat_elog_notice ("maximum sessions exceeded");
 594           return 0;
 595         }
 596
 597       make_sm_kv (&kv, &ip->dst_address, 0, 0, 0);
 598       if (clib_bihash_search_8_8
 599           (&sm->static_mapping_by_external, &kv, &value))
 600         {
 601           b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 602           return 0;
 603         }
 604
 605       m = pool_elt_at_index (sm->static_mappings, value.value);
 606
 607       new_addr = ip->dst_address.as_u32 = m->local_addr.as_u32;
 608
 609       /* Create a new session */
 610       s = nat_ed_session_alloc (sm, thread_index, now, ip->protocol);
 611       if (!s)
 612         {
 613           b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_USER_SESS_EXCEEDED];
 614           nat_elog_warn ("create NAT session failed");
 615           return 0;
 616         }
 617
 618       s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 619       s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 620       s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 621       s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 622       s->out2in.addr.as_u32 = old_addr;
 623       s->out2in.fib_index = rx_fib_index;
 624       s->in2out.addr.as_u32 = new_addr;
 625       s->in2out.fib_index = m->fib_index;
 626       s->in2out.port = s->out2in.port = ip->protocol;
 627
 628       /* Add to lookup tables */
 629       s_kv.value = s - tsm->sessions;
 630       if (clib_bihash_add_del_16_8 (&sm->out2in_ed, &s_kv, 1))
 631         nat_elog_notice ("out2in key add failed");
 632
 633       make_ed_kv (&ip->dst_address, &ip->src_address, ip->protocol,
 634                   m->fib_index, 0, 0, thread_index, s - tsm->sessions, &s_kv);
 635       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &s_kv, 1))
 636         nat_elog_notice ("in2out key add failed");
 637     }
 638
 639   /* Update IP checksum */
 640   sum = ip->checksum;
 641   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
 642   ip->checksum = ip_csum_fold (sum);
 643
 644   vnet_buffer (b)->sw_if_index[VLIB_TX] = s->in2out.fib_index;
 645
 646   /* Accounting */
 647   nat44_session_update_counters (s, now, vlib_buffer_length_in_chain (vm, b),
 648                                  thread_index);
 649   /* Per-user LRU list maintenance */
 650   nat44_session_update_lru (sm, s, thread_index);
 651
 652   return s;
 653 }
 654
 655 static inline uword
 656 nat44_ed_out2in_fast_path_node_fn_inline (vlib_main_t * vm,
 657                                           vlib_node_runtime_t * node,
 658                                           vlib_frame_t * frame,
 659                                           int is_multi_worker)
 660 {
 661   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
 662   nat_next_t next_index;
 663   snat_main_t *sm = &snat_main;
 664   f64 now = vlib_time_now (vm);
 665   u32 thread_index = vm->thread_index;
 666   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 667   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 668     0, fragments = 0;
 669
 670   stats_node_index = sm->ed_out2in_node_index;
 671
 672   from = vlib_frame_vector_args (frame);
 673   n_left_from = frame->n_vectors;
 674   next_index = node->cached_next_index;
 675
 676   while (n_left_from > 0)
 677     {
 678       u32 n_left_to_next;
 679
 680       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 681
 682       while (n_left_from > 0 && n_left_to_next > 0)
 683         {
 684           u32 bi0;
 685           vlib_buffer_t *b0;
 686           u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
 687             new_addr0;
 688           u16 old_port0, new_port0;
 689           ip4_header_t *ip0;
 690           udp_header_t *udp0;
 691           tcp_header_t *tcp0;
 692           snat_session_t *s0 = 0;
 693           clib_bihash_kv_16_8_t kv0, value0;
 694           ip_csum_t sum0;
 695
 696           /* speculatively enqueue b0 to the current next frame */
 697           bi0 = from[0];
 698           to_next[0] = bi0;
 699           from += 1;
 700           to_next += 1;
 701           n_left_from -= 1;
 702           n_left_to_next -= 1;
 703
 704           b0 = vlib_get_buffer (vm, bi0);
 705           next0 = vnet_buffer2 (b0)->nat.arc_next;
 706
 707           vnet_buffer (b0)->snat.flags = 0;
 708           ip0 = vlib_buffer_get_current (b0);
 709
 710           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 711           rx_fib_index0 =
 712             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 713                                                  sw_if_index0);
 714
 715           if (PREDICT_FALSE (ip0->ttl == 1))
 716             {
 717               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 718               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 719                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 720                                            0);
 721               next0 = NAT_NEXT_ICMP_ERROR;
 722               goto trace0;
 723             }
 724
 725           udp0 = ip4_next_header (ip0);
 726           tcp0 = (tcp_header_t *) udp0;
 727           proto0 = ip_proto_to_nat_proto (ip0->protocol);
 728
 729           if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
 730             {
 731               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 732               goto trace0;
 733             }
 734
 735           if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
 736             {
 737               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 738               goto trace0;
 739             }
 740
 741           make_ed_kv (&ip0->dst_address, &ip0->src_address,
 742                       ip0->protocol, rx_fib_index0,
 743                       vnet_buffer (b0)->ip.reass.l4_dst_port,
 744                       vnet_buffer (b0)->ip.reass.l4_src_port, ~0, ~0, &kv0);
 745
 746           /* there is a stashed index in vnet_buffer2 from handoff node,
 747            * see if we can use it */
 748           if (is_multi_worker && PREDICT_TRUE
 749               (!pool_is_free_index
 750                (tsm->sessions,
 751                 vnet_buffer2 (b0)->nat.ed_out2in_nat_session_index)))
 752             {
 753               s0 = pool_elt_at_index (tsm->sessions,
 754                                       vnet_buffer2 (b0)->
 755                                       nat.ed_out2in_nat_session_index);
 756               if (PREDICT_TRUE
 757                   (s0->out2in.addr.as_u32 == ip0->dst_address.as_u32
 758                    && s0->out2in.port ==
 759                    vnet_buffer (b0)->ip.reass.l4_dst_port
 760                    && s0->out2in.protocol ==
 761                    ip_proto_to_nat_proto (ip0->protocol)
 762                    && s0->out2in.fib_index == rx_fib_index0
 763                    && s0->ext_host_addr.as_u32 == ip0->src_address.as_u32
 764                    && s0->ext_host_port ==
 765                    vnet_buffer (b0)->ip.reass.l4_src_port))
 766                 {
 767                   /* yes, this is the droid we're looking for */
 768                   goto skip_lookup;
 769                 }
 770             }
 771
 772           if (clib_bihash_search_16_8 (&sm->out2in_ed, &kv0, &value0))
 773             {
 774               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 775               goto trace0;
 776             }
 777           ASSERT (thread_index == ed_value_get_thread_index (&value0));
 778           s0 =
 779             pool_elt_at_index (tsm->sessions,
 780                                ed_value_get_session_index (&value0));
 781
 782         skip_lookup:
 783           if (s0->tcp_closed_timestamp)
 784             {
 785               if (now >= s0->tcp_closed_timestamp)
 786                 {
 787                   // session is closed, go slow path
 788                   next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 789                 }
 790               else
 791                 {
 792                   // session in transitory timeout, drop
 793                   b0->error = node->errors[NAT_OUT2IN_ED_ERROR_TCP_CLOSED];
 794                   next0 = NAT_NEXT_DROP;
 795                 }
 796               goto trace0;
 797             }
 798
 799           // drop if session expired
 800           u64 sess_timeout_time;
 801           sess_timeout_time = s0->last_heard +
 802             (f64) nat44_session_get_timeout (sm, s0);
 803           if (now >= sess_timeout_time)
 804             {
 805               // session is closed, go slow path
 806               nat_free_session_data (sm, s0, thread_index, 0);
 807               nat_ed_session_delete (sm, s0, thread_index, 1);
 808               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 809               goto trace0;
 810             }
 811           //
 812
 813           old_addr0 = ip0->dst_address.as_u32;
 814           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
 815           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
 816
 817           sum0 = ip0->checksum;
 818           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 819                                  dst_address);
 820           if (PREDICT_FALSE (is_twice_nat_session (s0)))
 821             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 822                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
 823                                    src_address);
 824           ip0->checksum = ip_csum_fold (sum0);
 825
 826           old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
 827
 828           if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
 829             {
 830               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 831                 {
 832                   new_port0 = udp0->dst_port = s0->in2out.port;
 833                   sum0 = tcp0->checksum;
 834                   sum0 =
 835                     ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 836                                     dst_address);
 837                   sum0 =
 838                     ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 839                                     length);
 840                   if (is_twice_nat_session (s0))
 841                     {
 842                       sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 843                                              s0->ext_host_nat_addr.as_u32,
 844                                              ip4_header_t, dst_address);
 845                       sum0 =
 846                         ip_csum_update (sum0,
 847                                         vnet_buffer (b0)->ip.
 848                                         reass.l4_src_port,
 849                                         s0->ext_host_nat_port, ip4_header_t,
 850                                         length);
 851                       tcp0->src_port = s0->ext_host_nat_port;
 852                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 853                     }
 854                   tcp0->checksum = ip_csum_fold (sum0);
 855                 }
 856               tcp_packets++;
 857               if (nat44_set_tcp_session_state_o2i
 858                   (sm, now, s0,
 859                    vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags,
 860                    vnet_buffer (b0)->ip.reass.tcp_ack_number,
 861                    vnet_buffer (b0)->ip.reass.tcp_seq_number, thread_index))
 862                 goto trace0;
 863             }
 864           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
 865                    && udp0->checksum)
 866             {
 867               new_port0 = udp0->dst_port = s0->in2out.port;
 868               sum0 = udp0->checksum;
 869               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 870                                      dst_address);
 871               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 872                                      length);
 873               if (PREDICT_FALSE (is_twice_nat_session (s0)))
 874                 {
 875                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 876                                          s0->ext_host_nat_addr.as_u32,
 877                                          ip4_header_t, dst_address);
 878                   sum0 =
 879                     ip_csum_update (sum0,
 880                                     vnet_buffer (b0)->ip.reass.l4_src_port,
 881                                     s0->ext_host_nat_port, ip4_header_t,
 882                                     length);
 883                   udp0->src_port = s0->ext_host_nat_port;
 884                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 885                 }
 886               udp0->checksum = ip_csum_fold (sum0);
 887               udp_packets++;
 888             }
 889           else
 890             {
 891               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 892                 {
 893                   new_port0 = udp0->dst_port = s0->in2out.port;
 894                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
 895                     {
 896                       udp0->src_port = s0->ext_host_nat_port;
 897                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 898                     }
 899                 }
 900               udp_packets++;
 901             }
 902
 903           /* Accounting */
 904           nat44_session_update_counters (s0, now,
 905                                          vlib_buffer_length_in_chain (vm, b0),
 906                                          thread_index);
 907           /* Per-user LRU list maintenance */
 908           nat44_session_update_lru (sm, s0, thread_index);
 909
 910         trace0:
 911           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 912                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 913             {
 914               nat44_ed_out2in_trace_t *t =
 915                 vlib_add_trace (vm, node, b0, sizeof (*t));
 916               t->sw_if_index = sw_if_index0;
 917               t->next_index = next0;
 918               t->is_slow_path = 0;
 919
 920               if (s0)
 921                 t->session_index = s0 - tsm->sessions;
 922               else
 923                 t->session_index = ~0;
 924             }
 925
 926           pkts_processed += next0 == vnet_buffer2 (b0)->nat.arc_next;
 927           /* verify speculative enqueue, maybe switch current next frame */
 928           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 929                                            to_next, n_left_to_next,
 930                                            bi0, next0);
 931         }
 932
 933       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 934     }
 935
 936   vlib_node_increment_counter (vm, stats_node_index,
 937                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
 938                                pkts_processed);
 939   vlib_node_increment_counter (vm, stats_node_index,
 940                                NAT_OUT2IN_ED_ERROR_TCP_PACKETS, tcp_packets);
 941   vlib_node_increment_counter (vm, stats_node_index,
 942                                NAT_OUT2IN_ED_ERROR_UDP_PACKETS, udp_packets);
 943   vlib_node_increment_counter (vm, stats_node_index,
 944                                NAT_OUT2IN_ED_ERROR_ICMP_PACKETS,
 945                                icmp_packets);
 946   vlib_node_increment_counter (vm, stats_node_index,
 947                                NAT_OUT2IN_ED_ERROR_OTHER_PACKETS,
 948                                other_packets);
 949   vlib_node_increment_counter (vm, stats_node_index,
 950                                NAT_OUT2IN_ED_ERROR_FRAGMENTS, fragments);
 951   return frame->n_vectors;
 952 }
 953
 954 static inline uword
 955 nat44_ed_out2in_slow_path_node_fn_inline (vlib_main_t * vm,
 956                                           vlib_node_runtime_t * node,
 957                                           vlib_frame_t * frame)
 958 {
 959   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
 960   nat_next_t next_index;
 961   snat_main_t *sm = &snat_main;
 962   // HERE
 963   f64 now = vlib_time_now (vm);
 964   u32 thread_index = vm->thread_index;
 965   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 966   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 967     0, fragments = 0;
 968
 969   stats_node_index = sm->ed_out2in_slowpath_node_index;
 970
 971   from = vlib_frame_vector_args (frame);
 972   n_left_from = frame->n_vectors;
 973   next_index = node->cached_next_index;
 974
 975   while (n_left_from > 0)
 976     {
 977       u32 n_left_to_next;
 978
 979       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 980
 981       while (n_left_from > 0 && n_left_to_next > 0)
 982         {
 983           u32 bi0;
 984           vlib_buffer_t *b0;
 985           u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
 986             new_addr0;
 987           u16 old_port0, new_port0;
 988           ip4_header_t *ip0;
 989           udp_header_t *udp0;
 990           tcp_header_t *tcp0;
 991           icmp46_header_t *icmp0;
 992           snat_session_t *s0 = 0;
 993           clib_bihash_kv_16_8_t kv0, value0;
 994           ip_csum_t sum0;
 995           snat_session_key_t e_key0, l_key0;
 996           lb_nat_type_t lb_nat0;
 997           twice_nat_type_t twice_nat0;
 998           u8 identity_nat0;
 999
1000           /* speculatively enqueue b0 to the current next frame */
1001           bi0 = from[0];
1002           to_next[0] = bi0;
1003           from += 1;
1004           to_next += 1;
1005           n_left_from -= 1;
1006           n_left_to_next -= 1;
1007
1008           b0 = vlib_get_buffer (vm, bi0);
1009           next0 = vnet_buffer2 (b0)->nat.arc_next;
1010
1011           vnet_buffer (b0)->snat.flags = 0;
1012           ip0 = vlib_buffer_get_current (b0);
1013
1014           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1015           rx_fib_index0 =
1016             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
1017                                                  sw_if_index0);
1018
1019           if (PREDICT_FALSE (ip0->ttl == 1))
1020             {
1021               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1022               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1023                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1024                                            0);
1025               next0 = NAT_NEXT_ICMP_ERROR;
1026               goto trace0;
1027             }
1028
1029           udp0 = ip4_next_header (ip0);
1030           tcp0 = (tcp_header_t *) udp0;
1031           icmp0 = (icmp46_header_t *) udp0;
1032           proto0 = ip_proto_to_nat_proto (ip0->protocol);
1033
1034           if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
1035             {
1036               s0 =
1037                 nat44_ed_out2in_unknown_proto (sm, b0, ip0, rx_fib_index0,
1038                                                thread_index, now, vm, node);
1039               if (!sm->forwarding_enabled)
1040                 {
1041                   if (!s0)
1042                     next0 = NAT_NEXT_DROP;
1043                 }
1044               other_packets++;
1045               goto trace0;
1046             }
1047
1048           if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
1049             {
1050               next0 = icmp_out2in_ed_slow_path
1051                 (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1052                  next0, now, thread_index, &s0);
1053               icmp_packets++;
1054               goto trace0;
1055             }
1056
1057           make_ed_kv (&ip0->dst_address, &ip0->src_address,
1058                       ip0->protocol, rx_fib_index0,
1059                       vnet_buffer (b0)->ip.reass.l4_dst_port,
1060                       vnet_buffer (b0)->ip.reass.l4_src_port, ~0, ~0, &kv0);
1061
1062           s0 = NULL;
1063           if (!clib_bihash_search_16_8 (&sm->out2in_ed, &kv0, &value0))
1064             {
1065               ASSERT (thread_index == ed_value_get_thread_index (&value0));
1066               s0 =
1067                 pool_elt_at_index (tsm->sessions,
1068                                    ed_value_get_session_index (&value0));
1069
1070               if (s0->tcp_closed_timestamp && now >= s0->tcp_closed_timestamp)
1071                 {
1072                   nat_free_session_data (sm, s0, thread_index, 0);
1073                   nat_ed_session_delete (sm, s0, thread_index, 1);
1074                   s0 = NULL;
1075                 }
1076             }
1077
1078           if (!s0)
1079             {
1080               /* Try to match static mapping by external address and port,
1081                  destination address and port in packet */
1082               e_key0.addr = ip0->dst_address;
1083               e_key0.port = vnet_buffer (b0)->ip.reass.l4_dst_port;
1084               e_key0.protocol = proto0;
1085               e_key0.fib_index = rx_fib_index0;
1086
1087               if (snat_static_mapping_match (sm, e_key0, &l_key0, 1, 0,
1088                                              &twice_nat0, &lb_nat0,
1089                                              &ip0->src_address,
1090                                              &identity_nat0))
1091                 {
1092                   /*
1093                    * Send DHCP packets to the ipv4 stack, or we won't
1094                    * be able to use dhcp client on the outside interface
1095                    */
1096                   if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_UDP
1097                                      && (vnet_buffer (b0)->ip.
1098                                          reass.l4_dst_port ==
1099                                          clib_host_to_net_u16
1100                                          (UDP_DST_PORT_dhcp_to_client))))
1101                     {
1102                       goto trace0;
1103                     }
1104
1105                   if (!sm->forwarding_enabled)
1106                     {
1107                       b0->error =
1108                         node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
1109                       next0 = NAT_NEXT_DROP;
1110                     }
1111                   else
1112                     {
1113                       if (next_src_nat
1114                           (sm, ip0, vnet_buffer (b0)->ip.reass.l4_src_port,
1115                            vnet_buffer (b0)->ip.reass.l4_dst_port,
1116                            thread_index, rx_fib_index0))
1117                         {
1118                           next0 = NAT_NEXT_IN2OUT_ED_FAST_PATH;
1119                           goto trace0;
1120                         }
1121                       if (sm->num_workers > 1)
1122                         create_bypass_for_fwd_worker (sm, b0, ip0,
1123                                                       rx_fib_index0);
1124                       else
1125                         create_bypass_for_fwd (sm, b0, ip0, rx_fib_index0,
1126                                                thread_index);
1127                     }
1128                   goto trace0;
1129                 }
1130
1131               if (PREDICT_FALSE (identity_nat0))
1132                 goto trace0;
1133
1134               if ((proto0 == NAT_PROTOCOL_TCP)
1135                   && !tcp_flags_is_init (vnet_buffer (b0)->ip.
1136                                          reass.icmp_type_or_tcp_flags))
1137                 {
1138                   b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
1139                   next0 = NAT_NEXT_DROP;
1140                   goto trace0;
1141                 }
1142
1143               /* Create session initiated by host from external network */
1144               s0 = create_session_for_static_mapping_ed (sm, b0, l_key0,
1145                                                          e_key0, node,
1146                                                          rx_fib_index0,
1147                                                          thread_index,
1148                                                          twice_nat0,
1149                                                          lb_nat0, now);
1150               if (!s0)
1151                 {
1152                   next0 = NAT_NEXT_DROP;
1153                   goto trace0;
1154                 }
1155             }
1156
1157           old_addr0 = ip0->dst_address.as_u32;
1158           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
1159           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
1160
1161           sum0 = ip0->checksum;
1162           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1163                                  dst_address);
1164           if (PREDICT_FALSE (is_twice_nat_session (s0)))
1165             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1166                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
1167                                    src_address);
1168           ip0->checksum = ip_csum_fold (sum0);
1169
1170           old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
1171
1172           if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
1173             {
1174               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1175                 {
1176                   new_port0 = udp0->dst_port = s0->in2out.port;
1177                   sum0 = tcp0->checksum;
1178                   sum0 =
1179                     ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1180                                     dst_address);
1181                   sum0 =
1182                     ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1183                                     length);
1184                   if (is_twice_nat_session (s0))
1185                     {
1186                       sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1187                                              s0->ext_host_nat_addr.as_u32,
1188                                              ip4_header_t, dst_address);
1189                       sum0 =
1190                         ip_csum_update (sum0,
1191                                         vnet_buffer (b0)->ip.
1192                                         reass.l4_src_port,
1193                                         s0->ext_host_nat_port, ip4_header_t,
1194                                         length);
1195                       tcp0->src_port = s0->ext_host_nat_port;
1196                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1197                     }
1198                   tcp0->checksum = ip_csum_fold (sum0);
1199                 }
1200               tcp_packets++;
1201               if (nat44_set_tcp_session_state_o2i
1202                   (sm, now, s0,
1203                    vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags,
1204                    vnet_buffer (b0)->ip.reass.tcp_ack_number,
1205                    vnet_buffer (b0)->ip.reass.tcp_seq_number, thread_index))
1206                 goto trace0;
1207             }
1208           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
1209                    && udp0->checksum)
1210             {
1211               new_port0 = udp0->dst_port = s0->in2out.port;
1212               sum0 = udp0->checksum;
1213               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1214                                      dst_address);
1215               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1216                                      length);
1217               if (PREDICT_FALSE (is_twice_nat_session (s0)))
1218                 {
1219                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1220                                          s0->ext_host_nat_addr.as_u32,
1221                                          ip4_header_t, dst_address);
1222                   sum0 =
1223                     ip_csum_update (sum0,
1224                                     vnet_buffer (b0)->ip.reass.l4_src_port,
1225                                     s0->ext_host_nat_port, ip4_header_t,
1226                                     length);
1227                   udp0->src_port = s0->ext_host_nat_port;
1228                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1229                 }
1230               udp0->checksum = ip_csum_fold (sum0);
1231               udp_packets++;
1232             }
1233           else
1234             {
1235               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1236                 {
1237                   new_port0 = udp0->dst_port = s0->in2out.port;
1238                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
1239                     {
1240                       udp0->src_port = s0->ext_host_nat_port;
1241                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1242                     }
1243                 }
1244               udp_packets++;
1245             }
1246
1247           /* Accounting */
1248           nat44_session_update_counters (s0, now,
1249                                          vlib_buffer_length_in_chain (vm, b0),
1250                                          thread_index);
1251           /* Per-user LRU list maintenance */
1252           nat44_session_update_lru (sm, s0, thread_index);
1253
1254         trace0:
1255           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1256                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1257             {
1258               nat44_ed_out2in_trace_t *t =
1259                 vlib_add_trace (vm, node, b0, sizeof (*t));
1260               t->sw_if_index = sw_if_index0;
1261               t->next_index = next0;
1262               t->is_slow_path = 1;
1263
1264               if (s0)
1265                 t->session_index = s0 - tsm->sessions;
1266               else
1267                 t->session_index = ~0;
1268             }
1269
1270           pkts_processed += next0 == vnet_buffer2 (b0)->nat.arc_next;
1271           /* verify speculative enqueue, maybe switch current next frame */
1272           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1273                                            to_next, n_left_to_next,
1274                                            bi0, next0);
1275         }
1276
1277       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1278     }
1279
1280   vlib_node_increment_counter (vm, stats_node_index,
1281                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
1282                                pkts_processed);
1283   vlib_node_increment_counter (vm, stats_node_index,
1284                                NAT_OUT2IN_ED_ERROR_TCP_PACKETS, tcp_packets);
1285   vlib_node_increment_counter (vm, stats_node_index,
1286                                NAT_OUT2IN_ED_ERROR_UDP_PACKETS, udp_packets);
1287   vlib_node_increment_counter (vm, stats_node_index,
1288                                NAT_OUT2IN_ED_ERROR_ICMP_PACKETS,
1289                                icmp_packets);
1290   vlib_node_increment_counter (vm, stats_node_index,
1291                                NAT_OUT2IN_ED_ERROR_OTHER_PACKETS,
1292                                other_packets);
1293   vlib_node_increment_counter (vm, stats_node_index,
1294                                NAT_OUT2IN_ED_ERROR_FRAGMENTS, fragments);
1295   return frame->n_vectors;
1296 }
1297
1298 VLIB_NODE_FN (nat44_ed_out2in_node) (vlib_main_t * vm,
1299                                      vlib_node_runtime_t * node,
1300                                      vlib_frame_t * frame)
1301 {
1302   if (snat_main.num_workers > 1)
1303     {
1304       return nat44_ed_out2in_fast_path_node_fn_inline (vm, node, frame, 1);
1305     }
1306   else
1307     {
1308       return nat44_ed_out2in_fast_path_node_fn_inline (vm, node, frame, 0);
1309     }
1310 }
1311
1312 /* *INDENT-OFF* */
1313 VLIB_REGISTER_NODE (nat44_ed_out2in_node) = {
1314   .name = "nat44-ed-out2in",
1315   .vector_size = sizeof (u32),
1316   .sibling_of = "nat-default",
1317   .format_trace = format_nat44_ed_out2in_trace,
1318   .type = VLIB_NODE_TYPE_INTERNAL,
1319   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1320   .error_strings = nat_out2in_ed_error_strings,
1321   .runtime_data_bytes = sizeof (snat_runtime_t),
1322 };
1323 /* *INDENT-ON* */
1324
1325 VLIB_NODE_FN (nat44_ed_out2in_slowpath_node) (vlib_main_t * vm,
1326                                               vlib_node_runtime_t * node,
1327                                               vlib_frame_t * frame)
1328 {
1329   return nat44_ed_out2in_slow_path_node_fn_inline (vm, node, frame);
1330 }
1331
1332 /* *INDENT-OFF* */
1333 VLIB_REGISTER_NODE (nat44_ed_out2in_slowpath_node) = {
1334   .name = "nat44-ed-out2in-slowpath",
1335   .vector_size = sizeof (u32),
1336   .sibling_of = "nat-default",
1337   .format_trace = format_nat44_ed_out2in_trace,
1338   .type = VLIB_NODE_TYPE_INTERNAL,
1339   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1340   .error_strings = nat_out2in_ed_error_strings,
1341   .runtime_data_bytes = sizeof (snat_runtime_t),
1342 };
1343 /* *INDENT-ON* */
1344
1345 static u8 *
1346 format_nat_pre_trace (u8 * s, va_list * args)
1347 {
1348   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1349   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1350   nat_pre_trace_t *t = va_arg (*args, nat_pre_trace_t *);
1351   return format (s, "out2in next_index %d arc_next_index %d", t->next_index,
1352                  t->arc_next_index);
1353 }
1354
1355 VLIB_NODE_FN (nat_pre_out2in_node) (vlib_main_t * vm,
1356                                     vlib_node_runtime_t * node,
1357                                     vlib_frame_t * frame)
1358 {
1359   return nat_pre_node_fn_inline (vm, node, frame,
1360                                  NAT_NEXT_OUT2IN_ED_FAST_PATH);
1361 }
1362
1363 /* *INDENT-OFF* */
1364 VLIB_REGISTER_NODE (nat_pre_out2in_node) = {
1365   .name = "nat-pre-out2in",
1366   .vector_size = sizeof (u32),
1367   .sibling_of = "nat-default",
1368   .format_trace = format_nat_pre_trace,
1369   .type = VLIB_NODE_TYPE_INTERNAL,
1370   .n_errors = 0,
1371  };
1372 /* *INDENT-ON* */
1373
1374 /*
1375  * fd.io coding-style-patch-verification: ON
1376  *
1377  * Local Variables:
1378  * eval: (c-set-style "gnu")
1379  * End:
1380  */