src/plugins/nat/out2in_ed.c

   1 /*
   2  * Copyright (c) 2018 Cisco and/or its affiliates.
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15 /**
  16  * @file
  17  * @brief NAT44 endpoint-dependent outside to inside network translation
  18  */
  19
  20 #include <vlib/vlib.h>
  21 #include <vnet/vnet.h>
  22 #include <vnet/pg/pg.h>
  23 #include <vnet/ip/ip.h>
  24 #include <vnet/ethernet/ethernet.h>
  25 #include <vnet/fib/ip4_fib.h>
  26 #include <vnet/udp/udp.h>
  27 #include <vppinfra/error.h>
  28 #include <nat/nat.h>
  29 #include <nat/nat_ipfix_logging.h>
  30 #include <nat/nat_inlines.h>
  31 #include <nat/nat44/inlines.h>
  32 #include <nat/nat_syslog.h>
  33 #include <nat/nat_ha.h>
  34
  35 static char *nat_out2in_ed_error_strings[] = {
  36 #define _(sym,string) string,
  37   foreach_nat_out2in_ed_error
  38 #undef _
  39 };
  40
  41 typedef struct
  42 {
  43   u32 sw_if_index;
  44   u32 next_index;
  45   u32 session_index;
  46   u32 is_slow_path;
  47 } nat44_ed_out2in_trace_t;
  48
  49 static u8 *
  50 format_nat44_ed_out2in_trace (u8 * s, va_list * args)
  51 {
  52   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  53   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  54   nat44_ed_out2in_trace_t *t = va_arg (*args, nat44_ed_out2in_trace_t *);
  55   char *tag;
  56
  57   tag =
  58     t->is_slow_path ? "NAT44_OUT2IN_ED_SLOW_PATH" :
  59     "NAT44_OUT2IN_ED_FAST_PATH";
  60
  61   s = format (s, "%s: sw_if_index %d, next index %d, session %d", tag,
  62               t->sw_if_index, t->next_index, t->session_index);
  63
  64   return s;
  65 }
  66
  67 static inline u32
  68 icmp_out2in_ed_slow_path (snat_main_t * sm, vlib_buffer_t * b0,
  69                           ip4_header_t * ip0, icmp46_header_t * icmp0,
  70                           u32 sw_if_index0, u32 rx_fib_index0,
  71                           vlib_node_runtime_t * node, u32 next0, f64 now,
  72                           u32 thread_index, snat_session_t ** p_s0)
  73 {
  74   vlib_main_t *vm = vlib_get_main ();
  75
  76   next0 = icmp_out2in (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
  77                        next0, thread_index, p_s0, 0);
  78   snat_session_t *s0 = *p_s0;
  79   if (PREDICT_TRUE (next0 != NAT_NEXT_DROP && s0))
  80     {
  81       /* Accounting */
  82       nat44_session_update_counters (s0, now,
  83                                      vlib_buffer_length_in_chain
  84                                      (vm, b0), thread_index);
  85       /* Per-user LRU list maintenance */
  86       nat44_session_update_lru (sm, s0, thread_index);
  87     }
  88   return next0;
  89 }
  90
  91 #ifndef CLIB_MARCH_VARIANT
  92 int
  93 nat44_o2i_ed_is_idle_session_cb (clib_bihash_kv_16_8_t * kv, void *arg)
  94 {
  95   snat_main_t *sm = &snat_main;
  96   nat44_is_idle_session_ctx_t *ctx = arg;
  97   snat_session_t *s;
  98   u64 sess_timeout_time;
  99   u8 proto;
 100   u16 r_port, l_port;
 101   ip4_address_t *l_addr, *r_addr;
 102   u32 fib_index;
 103   clib_bihash_kv_16_8_t ed_kv;
 104   int i;
 105   snat_address_t *a;
 106   snat_session_key_t key;
 107   snat_main_per_thread_data_t *tsm = vec_elt_at_index (sm->per_thread_data,
 108                                                        ctx->thread_index);
 109
 110   s = pool_elt_at_index (tsm->sessions, kv->value);
 111   sess_timeout_time = s->last_heard + (f64) nat44_session_get_timeout (sm, s);
 112   if (ctx->now >= sess_timeout_time)
 113     {
 114       l_addr = &s->in2out.addr;
 115       r_addr = &s->ext_host_addr;
 116       fib_index = s->in2out.fib_index;
 117       if (snat_is_unk_proto_session (s))
 118         {
 119           proto = s->in2out.port;
 120           r_port = 0;
 121           l_port = 0;
 122         }
 123       else
 124         {
 125           proto = snat_proto_to_ip_proto (s->in2out.protocol);
 126           l_port = s->in2out.port;
 127           r_port = s->ext_host_port;
 128         }
 129       if (is_twice_nat_session (s))
 130         {
 131           r_addr = &s->ext_host_nat_addr;
 132           r_port = s->ext_host_nat_port;
 133         }
 134       make_ed_kv (l_addr, r_addr, proto, fib_index, l_port, r_port, ~0ULL,
 135                   &ed_kv);
 136       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &ed_kv, 0))
 137         nat_elog_warn ("in2out_ed key del failed");
 138
 139       if (snat_is_unk_proto_session (s))
 140         goto delete;
 141
 142       snat_ipfix_logging_nat44_ses_delete (ctx->thread_index,
 143                                            s->in2out.addr.as_u32,
 144                                            s->out2in.addr.as_u32,
 145                                            s->in2out.protocol,
 146                                            s->in2out.port,
 147                                            s->out2in.port,
 148                                            s->in2out.fib_index);
 149
 150       nat_syslog_nat44_sdel (s->user_index, s->in2out.fib_index,
 151                              &s->in2out.addr, s->in2out.port,
 152                              &s->ext_host_nat_addr, s->ext_host_nat_port,
 153                              &s->out2in.addr, s->out2in.port,
 154                              &s->ext_host_addr, s->ext_host_port,
 155                              s->in2out.protocol, is_twice_nat_session (s));
 156
 157       nat_ha_sdel (&s->out2in.addr, s->out2in.port, &s->ext_host_addr,
 158                    s->ext_host_port, s->out2in.protocol, s->out2in.fib_index,
 159                    ctx->thread_index);
 160
 161       if (is_twice_nat_session (s))
 162         {
 163           for (i = 0; i < vec_len (sm->twice_nat_addresses); i++)
 164             {
 165               key.protocol = s->in2out.protocol;
 166               key.port = s->ext_host_nat_port;
 167               a = sm->twice_nat_addresses + i;
 168               if (a->addr.as_u32 == s->ext_host_nat_addr.as_u32)
 169                 {
 170                   snat_free_outside_address_and_port (sm->twice_nat_addresses,
 171                                                       ctx->thread_index,
 172                                                       &key);
 173                   break;
 174                 }
 175             }
 176         }
 177
 178       if (snat_is_session_static (s))
 179         goto delete;
 180
 181       snat_free_outside_address_and_port (sm->addresses, ctx->thread_index,
 182                                           &s->out2in);
 183     delete:
 184       nat44_ed_delete_session (sm, s, ctx->thread_index, 1);
 185       return 1;
 186     }
 187
 188   return 0;
 189 }
 190 #endif
 191
 192 static snat_session_t *
 193 create_session_for_static_mapping_ed (snat_main_t * sm,
 194                                       vlib_buffer_t * b,
 195                                       snat_session_key_t l_key,
 196                                       snat_session_key_t e_key,
 197                                       vlib_node_runtime_t * node,
 198                                       u32 rx_fib_index,
 199                                       u32 thread_index,
 200                                       twice_nat_type_t twice_nat,
 201                                       lb_nat_type_t lb_nat, f64 now)
 202 {
 203   snat_session_t *s;
 204   ip4_header_t *ip;
 205   udp_header_t *udp;
 206   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 207   clib_bihash_kv_16_8_t kv;
 208   snat_session_key_t eh_key;
 209   nat44_is_idle_session_ctx_t ctx;
 210
 211   if (PREDICT_FALSE
 212       (nat44_ed_maximum_sessions_exceeded (sm, rx_fib_index, thread_index)))
 213     {
 214       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 215       nat_elog_notice ("maximum sessions exceeded");
 216       return 0;
 217     }
 218
 219   s = nat_ed_session_alloc (sm, thread_index, now);
 220   if (!s)
 221     {
 222       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_USER_SESS_EXCEEDED];
 223       nat_elog_warn ("create NAT session failed");
 224       return 0;
 225     }
 226
 227   ip = vlib_buffer_get_current (b);
 228   udp = ip4_next_header (ip);
 229
 230   s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 231   s->ext_host_port = e_key.protocol == SNAT_PROTOCOL_ICMP ? 0 : udp->src_port;
 232   s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 233   if (lb_nat)
 234     s->flags |= SNAT_SESSION_FLAG_LOAD_BALANCING;
 235   if (lb_nat == AFFINITY_LB_NAT)
 236     s->flags |= SNAT_SESSION_FLAG_AFFINITY;
 237   s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 238   s->out2in = e_key;
 239   s->in2out = l_key;
 240   s->in2out.protocol = s->out2in.protocol;
 241
 242   /* Add to lookup tables */
 243   make_ed_kv (&e_key.addr, &s->ext_host_addr, ip->protocol,
 244               e_key.fib_index, e_key.port, s->ext_host_port,
 245               s - tsm->sessions, &kv);
 246   ctx.now = now;
 247   ctx.thread_index = thread_index;
 248   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->out2in_ed, &kv,
 249                                                nat44_o2i_ed_is_idle_session_cb,
 250                                                &ctx))
 251     nat_elog_notice ("out2in-ed key add failed");
 252
 253   if (twice_nat == TWICE_NAT || (twice_nat == TWICE_NAT_SELF &&
 254                                  ip->src_address.as_u32 == l_key.addr.as_u32))
 255     {
 256       eh_key.protocol = e_key.protocol;
 257       if (snat_alloc_outside_address_and_port (sm->twice_nat_addresses, 0,
 258                                                thread_index, &eh_key,
 259                                                sm->port_per_thread,
 260                                                tsm->snat_thread_index))
 261         {
 262           b->error = node->errors[NAT_OUT2IN_ED_ERROR_OUT_OF_PORTS];
 263           nat44_ed_delete_session (sm, s, thread_index, 1);
 264           if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &kv, 0))
 265             nat_elog_notice ("out2in-ed key del failed");
 266           return 0;
 267         }
 268       s->ext_host_nat_addr.as_u32 = eh_key.addr.as_u32;
 269       s->ext_host_nat_port = eh_key.port;
 270       s->flags |= SNAT_SESSION_FLAG_TWICE_NAT;
 271       make_ed_kv (&l_key.addr, &s->ext_host_nat_addr, ip->protocol,
 272                   l_key.fib_index, l_key.port, s->ext_host_nat_port,
 273                   s - tsm->sessions, &kv);
 274     }
 275   else
 276     {
 277       make_ed_kv (&l_key.addr, &s->ext_host_addr, ip->protocol,
 278                   l_key.fib_index, l_key.port, s->ext_host_port,
 279                   s - tsm->sessions, &kv);
 280     }
 281   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->in2out_ed, &kv,
 282                                                nat44_i2o_ed_is_idle_session_cb,
 283                                                &ctx))
 284     nat_elog_notice ("in2out-ed key add failed");
 285
 286   snat_ipfix_logging_nat44_ses_create (thread_index,
 287                                        s->in2out.addr.as_u32,
 288                                        s->out2in.addr.as_u32,
 289                                        s->in2out.protocol,
 290                                        s->in2out.port,
 291                                        s->out2in.port, s->in2out.fib_index);
 292
 293   nat_syslog_nat44_sadd (s->user_index, s->in2out.fib_index,
 294                          &s->in2out.addr, s->in2out.port,
 295                          &s->ext_host_nat_addr, s->ext_host_nat_port,
 296                          &s->out2in.addr, s->out2in.port,
 297                          &s->ext_host_addr, s->ext_host_port,
 298                          s->in2out.protocol, is_twice_nat_session (s));
 299
 300   nat_ha_sadd (&s->in2out.addr, s->in2out.port, &s->out2in.addr,
 301                s->out2in.port, &s->ext_host_addr, s->ext_host_port,
 302                &s->ext_host_nat_addr, s->ext_host_nat_port,
 303                s->in2out.protocol, s->in2out.fib_index, s->flags,
 304                thread_index, 0);
 305
 306   return s;
 307 }
 308
 309 static int
 310 next_src_nat (snat_main_t * sm, ip4_header_t * ip, u16 src_port,
 311               u16 dst_port, u32 thread_index, u32 rx_fib_index)
 312 {
 313   clib_bihash_kv_16_8_t kv, value;
 314   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 315
 316   make_ed_kv (&ip->src_address, &ip->dst_address, ip->protocol,
 317               rx_fib_index, src_port, dst_port, ~0ULL, &kv);
 318   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 319     return 1;
 320
 321   return 0;
 322 }
 323
 324 static void
 325 create_bypass_for_fwd (snat_main_t * sm, vlib_buffer_t * b, ip4_header_t * ip,
 326                        u32 rx_fib_index, u32 thread_index)
 327 {
 328   clib_bihash_kv_16_8_t kv, value;
 329   udp_header_t *udp;
 330   snat_session_t *s = 0;
 331   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 332   vlib_main_t *vm = vlib_get_main ();
 333   f64 now = vlib_time_now (vm);
 334   u16 l_port, r_port;
 335
 336   if (ip->protocol == IP_PROTOCOL_ICMP)
 337     {
 338       if (get_icmp_o2i_ed_key
 339           (b, ip, rx_fib_index, ~0ULL, 0, &l_port, &r_port, &kv))
 340         return;
 341     }
 342   else
 343     {
 344       if (ip->protocol == IP_PROTOCOL_UDP || ip->protocol == IP_PROTOCOL_TCP)
 345         {
 346           udp = ip4_next_header (ip);
 347           l_port = udp->dst_port;
 348           r_port = udp->src_port;
 349         }
 350       else
 351         {
 352           l_port = 0;
 353           r_port = 0;
 354         }
 355       make_ed_kv (&ip->dst_address, &ip->src_address, ip->protocol,
 356                   rx_fib_index, l_port, r_port, ~0ULL, &kv);
 357     }
 358
 359   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 360     {
 361       s = pool_elt_at_index (tsm->sessions, value.value);
 362     }
 363   else
 364     {
 365       u32 proto;
 366
 367       if (PREDICT_FALSE
 368           (nat44_ed_maximum_sessions_exceeded
 369            (sm, rx_fib_index, thread_index)))
 370         return;
 371
 372       s = nat_ed_session_alloc (sm, thread_index, now);
 373       if (!s)
 374         {
 375           nat_elog_warn ("create NAT session failed");
 376           return;
 377         }
 378
 379       proto = ip_proto_to_snat_proto (ip->protocol);
 380
 381       s->ext_host_addr = ip->src_address;
 382       s->ext_host_port = r_port;
 383       s->flags |= SNAT_SESSION_FLAG_FWD_BYPASS;
 384       s->out2in.addr = ip->dst_address;
 385       s->out2in.port = l_port;
 386       s->out2in.protocol = proto;
 387       if (proto == ~0)
 388         {
 389           s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 390           s->out2in.port = ip->protocol;
 391         }
 392       s->out2in.fib_index = 0;
 393       s->in2out = s->out2in;
 394
 395       kv.value = s - tsm->sessions;
 396       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &kv, 1))
 397         nat_elog_notice ("in2out_ed key add failed");
 398     }
 399
 400   if (ip->protocol == IP_PROTOCOL_TCP)
 401     {
 402       tcp_header_t *tcp = ip4_next_header (ip);
 403       if (nat44_set_tcp_session_state_o2i
 404           (sm, now, s, tcp->flags, tcp->ack_number, tcp->seq_number,
 405            thread_index))
 406         return;
 407     }
 408
 409   /* Accounting */
 410   nat44_session_update_counters (s, now, 0, thread_index);
 411   /* Per-user LRU list maintenance */
 412   nat44_session_update_lru (sm, s, thread_index);
 413 }
 414
 415 static inline void
 416 create_bypass_for_fwd_worker (snat_main_t * sm, vlib_buffer_t * b,
 417                               ip4_header_t * ip, u32 rx_fib_index)
 418 {
 419   ip4_header_t ip_wkr = {
 420     .src_address = ip->dst_address,
 421   };
 422   u32 thread_index = sm->worker_in2out_cb (&ip_wkr, rx_fib_index, 0);
 423
 424   create_bypass_for_fwd (sm, b, ip, rx_fib_index, thread_index);
 425 }
 426
 427 #ifndef CLIB_MARCH_VARIANT
 428 u32
 429 icmp_match_out2in_ed (snat_main_t * sm, vlib_node_runtime_t * node,
 430                       u32 thread_index, vlib_buffer_t * b, ip4_header_t * ip,
 431                       u8 * p_proto, snat_session_key_t * p_value,
 432                       u8 * p_dont_translate, void *d, void *e)
 433 {
 434   u32 next = ~0, sw_if_index, rx_fib_index;
 435   clib_bihash_kv_16_8_t kv, value;
 436   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 437   snat_session_t *s = 0;
 438   u8 dont_translate = 0, is_addr_only, identity_nat;
 439   snat_session_key_t e_key, l_key;
 440   u16 l_port, r_port;
 441   vlib_main_t *vm = vlib_get_main ();
 442
 443   sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
 444   rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 445
 446   if (get_icmp_o2i_ed_key
 447       (b, ip, rx_fib_index, ~0ULL, p_proto, &l_port, &r_port, &kv))
 448     {
 449       b->error = node->errors[NAT_OUT2IN_ED_ERROR_UNSUPPORTED_PROTOCOL];
 450       next = NAT_NEXT_DROP;
 451       goto out;
 452     }
 453
 454   if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv, &value))
 455     {
 456       /* Try to match static mapping */
 457       e_key.addr = ip->dst_address;
 458       e_key.port = l_port;
 459       e_key.protocol = ip_proto_to_snat_proto (ip->protocol);
 460       e_key.fib_index = rx_fib_index;
 461       if (snat_static_mapping_match
 462           (sm, e_key, &l_key, 1, &is_addr_only, 0, 0, 0, &identity_nat))
 463         {
 464           if (!sm->forwarding_enabled)
 465             {
 466               /* Don't NAT packet aimed at the intfc address */
 467               if (PREDICT_FALSE (is_interface_addr (sm, node, sw_if_index,
 468                                                     ip->dst_address.as_u32)))
 469                 {
 470                   dont_translate = 1;
 471                   goto out;
 472                 }
 473               b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 474               next = NAT_NEXT_DROP;
 475               goto out;
 476             }
 477           else
 478             {
 479               dont_translate = 1;
 480               if (next_src_nat (sm, ip, l_port, r_port,
 481                                 thread_index, rx_fib_index))
 482                 {
 483                   next = NAT_NEXT_IN2OUT_ED_FAST_PATH;
 484                   goto out;
 485                 }
 486               if (sm->num_workers > 1)
 487                 create_bypass_for_fwd_worker (sm, b, ip, rx_fib_index);
 488               else
 489                 create_bypass_for_fwd (sm, b, ip, rx_fib_index, thread_index);
 490               goto out;
 491             }
 492         }
 493
 494       if (PREDICT_FALSE
 495           (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 496            ICMP4_echo_reply
 497            && (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 498                ICMP4_echo_request || !is_addr_only)))
 499         {
 500           b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 501           next = NAT_NEXT_DROP;
 502           goto out;
 503         }
 504
 505       if (PREDICT_FALSE (identity_nat))
 506         {
 507           dont_translate = 1;
 508           goto out;
 509         }
 510
 511       /* Create session initiated by host from external network */
 512       s = create_session_for_static_mapping_ed (sm, b, l_key, e_key, node,
 513                                                 rx_fib_index, thread_index, 0,
 514                                                 0, vlib_time_now (vm));
 515
 516       if (!s)
 517         {
 518           next = NAT_NEXT_DROP;
 519           goto out;
 520         }
 521     }
 522   else
 523     {
 524       if (PREDICT_FALSE
 525           (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 526            ICMP4_echo_reply
 527            && vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 528            ICMP4_echo_request
 529            && !icmp_type_is_error_message (vnet_buffer (b)->ip.
 530                                            reass.icmp_type_or_tcp_flags)))
 531         {
 532           b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 533           next = NAT_NEXT_DROP;
 534           goto out;
 535         }
 536
 537       s = pool_elt_at_index (tsm->sessions, value.value);
 538     }
 539 out:
 540   if (s)
 541     *p_value = s->in2out;
 542   *p_dont_translate = dont_translate;
 543   if (d)
 544     *(snat_session_t **) d = s;
 545   return next;
 546 }
 547 #endif
 548
 549 static snat_session_t *
 550 nat44_ed_out2in_unknown_proto (snat_main_t * sm,
 551                                vlib_buffer_t * b,
 552                                ip4_header_t * ip,
 553                                u32 rx_fib_index,
 554                                u32 thread_index,
 555                                f64 now,
 556                                vlib_main_t * vm, vlib_node_runtime_t * node)
 557 {
 558   clib_bihash_kv_8_8_t kv, value;
 559   clib_bihash_kv_16_8_t s_kv, s_value;
 560   snat_static_mapping_t *m;
 561   u32 old_addr, new_addr;
 562   ip_csum_t sum;
 563   snat_session_t *s;
 564   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 565
 566   old_addr = ip->dst_address.as_u32;
 567
 568   make_ed_kv (&ip->dst_address, &ip->src_address, ip->protocol, rx_fib_index,
 569               0, 0, ~0ULL, &s_kv);
 570
 571   if (!clib_bihash_search_16_8 (&tsm->out2in_ed, &s_kv, &s_value))
 572     {
 573       s = pool_elt_at_index (tsm->sessions, s_value.value);
 574       new_addr = ip->dst_address.as_u32 = s->in2out.addr.as_u32;
 575     }
 576   else
 577     {
 578       if (PREDICT_FALSE
 579           (nat44_ed_maximum_sessions_exceeded
 580            (sm, rx_fib_index, thread_index)))
 581         {
 582           b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 583           nat_elog_notice ("maximum sessions exceeded");
 584           return 0;
 585         }
 586
 587       make_sm_kv (&kv, &ip->dst_address, 0, 0, 0);
 588       if (clib_bihash_search_8_8
 589           (&sm->static_mapping_by_external, &kv, &value))
 590         {
 591           b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 592           return 0;
 593         }
 594
 595       m = pool_elt_at_index (sm->static_mappings, value.value);
 596
 597       new_addr = ip->dst_address.as_u32 = m->local_addr.as_u32;
 598
 599       /* Create a new session */
 600       s = nat_ed_session_alloc (sm, thread_index, now);
 601       if (!s)
 602         {
 603           b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_USER_SESS_EXCEEDED];
 604           nat_elog_warn ("create NAT session failed");
 605           return 0;
 606         }
 607
 608       s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 609       s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 610       s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 611       s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 612       s->out2in.addr.as_u32 = old_addr;
 613       s->out2in.fib_index = rx_fib_index;
 614       s->in2out.addr.as_u32 = new_addr;
 615       s->in2out.fib_index = m->fib_index;
 616       s->in2out.port = s->out2in.port = ip->protocol;
 617
 618       /* Add to lookup tables */
 619       s_kv.value = s - tsm->sessions;
 620       if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &s_kv, 1))
 621         nat_elog_notice ("out2in key add failed");
 622
 623       make_ed_kv (&ip->dst_address, &ip->src_address, ip->protocol,
 624                   m->fib_index, 0, 0, s - tsm->sessions, &s_kv);
 625       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &s_kv, 1))
 626         nat_elog_notice ("in2out key add failed");
 627     }
 628
 629   /* Update IP checksum */
 630   sum = ip->checksum;
 631   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
 632   ip->checksum = ip_csum_fold (sum);
 633
 634   vnet_buffer (b)->sw_if_index[VLIB_TX] = s->in2out.fib_index;
 635
 636   /* Accounting */
 637   nat44_session_update_counters (s, now, vlib_buffer_length_in_chain (vm, b),
 638                                  thread_index);
 639   /* Per-user LRU list maintenance */
 640   nat44_session_update_lru (sm, s, thread_index);
 641
 642   return s;
 643 }
 644
 645 static inline uword
 646 nat44_ed_out2in_fast_path_node_fn_inline (vlib_main_t * vm,
 647                                           vlib_node_runtime_t * node,
 648                                           vlib_frame_t * frame)
 649 {
 650   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
 651   nat_next_t next_index;
 652   snat_main_t *sm = &snat_main;
 653   f64 now = vlib_time_now (vm);
 654   u32 thread_index = vm->thread_index;
 655   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 656   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 657     0, fragments = 0;
 658
 659   stats_node_index = sm->ed_out2in_node_index;
 660
 661   from = vlib_frame_vector_args (frame);
 662   n_left_from = frame->n_vectors;
 663   next_index = node->cached_next_index;
 664
 665   while (n_left_from > 0)
 666     {
 667       u32 n_left_to_next;
 668
 669       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 670
 671       while (n_left_from > 0 && n_left_to_next > 0)
 672         {
 673           u32 bi0;
 674           vlib_buffer_t *b0;
 675           u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
 676             new_addr0;
 677           u16 old_port0, new_port0;
 678           ip4_header_t *ip0;
 679           udp_header_t *udp0;
 680           tcp_header_t *tcp0;
 681           snat_session_t *s0 = 0;
 682           clib_bihash_kv_16_8_t kv0, value0;
 683           ip_csum_t sum0;
 684
 685           /* speculatively enqueue b0 to the current next frame */
 686           bi0 = from[0];
 687           to_next[0] = bi0;
 688           from += 1;
 689           to_next += 1;
 690           n_left_from -= 1;
 691           n_left_to_next -= 1;
 692
 693           b0 = vlib_get_buffer (vm, bi0);
 694           next0 = vnet_buffer2 (b0)->nat.arc_next;
 695
 696           vnet_buffer (b0)->snat.flags = 0;
 697           ip0 = vlib_buffer_get_current (b0);
 698
 699           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 700           rx_fib_index0 =
 701             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 702                                                  sw_if_index0);
 703
 704           if (PREDICT_FALSE (ip0->ttl == 1))
 705             {
 706               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 707               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 708                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 709                                            0);
 710               next0 = NAT_NEXT_ICMP_ERROR;
 711               goto trace0;
 712             }
 713
 714           udp0 = ip4_next_header (ip0);
 715           tcp0 = (tcp_header_t *) udp0;
 716           proto0 = ip_proto_to_snat_proto (ip0->protocol);
 717
 718           if (PREDICT_FALSE (proto0 == ~0))
 719             {
 720               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 721               goto trace0;
 722             }
 723
 724           if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
 725             {
 726               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 727               goto trace0;
 728             }
 729
 730           make_ed_kv (&ip0->dst_address, &ip0->src_address,
 731                       ip0->protocol, rx_fib_index0,
 732                       vnet_buffer (b0)->ip.reass.l4_dst_port,
 733                       vnet_buffer (b0)->ip.reass.l4_src_port, ~0ULL, &kv0);
 734
 735           if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv0, &value0))
 736             {
 737               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 738               goto trace0;
 739             }
 740           s0 = pool_elt_at_index (tsm->sessions, value0.value);
 741
 742           if (s0->tcp_close_timestamp)
 743             {
 744               if (now >= s0->tcp_close_timestamp)
 745                 {
 746                   // session is closed, go slow path
 747                   next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 748                 }
 749               else
 750                 {
 751                   // session in transitory timeout, drop
 752                   b0->error = node->errors[NAT_OUT2IN_ED_ERROR_TCP_CLOSED];
 753                   next0 = NAT_NEXT_DROP;
 754                 }
 755               goto trace0;
 756             }
 757
 758           // drop if session expired
 759           u64 sess_timeout_time;
 760           sess_timeout_time = s0->last_heard +
 761             (f64) nat44_session_get_timeout (sm, s0);
 762           if (now >= sess_timeout_time)
 763             {
 764               // session is closed, go slow path
 765               nat_free_session_data (sm, s0, thread_index, 0);
 766               nat44_ed_delete_session (sm, s0, thread_index, 1);
 767               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 768               goto trace0;
 769             }
 770           //
 771
 772           old_addr0 = ip0->dst_address.as_u32;
 773           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
 774           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
 775
 776           sum0 = ip0->checksum;
 777           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 778                                  dst_address);
 779           if (PREDICT_FALSE (is_twice_nat_session (s0)))
 780             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 781                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
 782                                    src_address);
 783           ip0->checksum = ip_csum_fold (sum0);
 784
 785           old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
 786
 787           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
 788             {
 789               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 790                 {
 791                   new_port0 = udp0->dst_port = s0->in2out.port;
 792                   sum0 = tcp0->checksum;
 793                   sum0 =
 794                     ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 795                                     dst_address);
 796                   sum0 =
 797                     ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 798                                     length);
 799                   if (is_twice_nat_session (s0))
 800                     {
 801                       sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 802                                              s0->ext_host_nat_addr.as_u32,
 803                                              ip4_header_t, dst_address);
 804                       sum0 =
 805                         ip_csum_update (sum0,
 806                                         vnet_buffer (b0)->ip.
 807                                         reass.l4_src_port,
 808                                         s0->ext_host_nat_port, ip4_header_t,
 809                                         length);
 810                       tcp0->src_port = s0->ext_host_nat_port;
 811                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 812                     }
 813                   tcp0->checksum = ip_csum_fold (sum0);
 814                 }
 815               tcp_packets++;
 816               if (nat44_set_tcp_session_state_o2i
 817                   (sm, now, s0,
 818                    vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags,
 819                    vnet_buffer (b0)->ip.reass.tcp_ack_number,
 820                    vnet_buffer (b0)->ip.reass.tcp_seq_number, thread_index))
 821                 goto trace0;
 822             }
 823           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
 824                    && udp0->checksum)
 825             {
 826               new_port0 = udp0->dst_port = s0->in2out.port;
 827               sum0 = udp0->checksum;
 828               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 829                                      dst_address);
 830               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 831                                      length);
 832               if (PREDICT_FALSE (is_twice_nat_session (s0)))
 833                 {
 834                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 835                                          s0->ext_host_nat_addr.as_u32,
 836                                          ip4_header_t, dst_address);
 837                   sum0 =
 838                     ip_csum_update (sum0,
 839                                     vnet_buffer (b0)->ip.reass.l4_src_port,
 840                                     s0->ext_host_nat_port, ip4_header_t,
 841                                     length);
 842                   udp0->src_port = s0->ext_host_nat_port;
 843                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 844                 }
 845               udp0->checksum = ip_csum_fold (sum0);
 846               udp_packets++;
 847             }
 848           else
 849             {
 850               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 851                 {
 852                   new_port0 = udp0->dst_port = s0->in2out.port;
 853                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
 854                     {
 855                       udp0->src_port = s0->ext_host_nat_port;
 856                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 857                     }
 858                 }
 859               udp_packets++;
 860             }
 861
 862           /* Accounting */
 863           nat44_session_update_counters (s0, now,
 864                                          vlib_buffer_length_in_chain (vm, b0),
 865                                          thread_index);
 866           /* Per-user LRU list maintenance */
 867           nat44_session_update_lru (sm, s0, thread_index);
 868
 869         trace0:
 870           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 871                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 872             {
 873               nat44_ed_out2in_trace_t *t =
 874                 vlib_add_trace (vm, node, b0, sizeof (*t));
 875               t->sw_if_index = sw_if_index0;
 876               t->next_index = next0;
 877               t->is_slow_path = 0;
 878
 879               if (s0)
 880                 t->session_index = s0 - tsm->sessions;
 881               else
 882                 t->session_index = ~0;
 883             }
 884
 885           pkts_processed += next0 == vnet_buffer2 (b0)->nat.arc_next;
 886           /* verify speculative enqueue, maybe switch current next frame */
 887           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 888                                            to_next, n_left_to_next,
 889                                            bi0, next0);
 890         }
 891
 892       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 893     }
 894
 895   vlib_node_increment_counter (vm, stats_node_index,
 896                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
 897                                pkts_processed);
 898   vlib_node_increment_counter (vm, stats_node_index,
 899                                NAT_OUT2IN_ED_ERROR_TCP_PACKETS, tcp_packets);
 900   vlib_node_increment_counter (vm, stats_node_index,
 901                                NAT_OUT2IN_ED_ERROR_UDP_PACKETS, udp_packets);
 902   vlib_node_increment_counter (vm, stats_node_index,
 903                                NAT_OUT2IN_ED_ERROR_ICMP_PACKETS,
 904                                icmp_packets);
 905   vlib_node_increment_counter (vm, stats_node_index,
 906                                NAT_OUT2IN_ED_ERROR_OTHER_PACKETS,
 907                                other_packets);
 908   vlib_node_increment_counter (vm, stats_node_index,
 909                                NAT_OUT2IN_ED_ERROR_FRAGMENTS, fragments);
 910   return frame->n_vectors;
 911 }
 912
 913 static inline uword
 914 nat44_ed_out2in_slow_path_node_fn_inline (vlib_main_t * vm,
 915                                           vlib_node_runtime_t * node,
 916                                           vlib_frame_t * frame)
 917 {
 918   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
 919   nat_next_t next_index;
 920   snat_main_t *sm = &snat_main;
 921   // HERE
 922   f64 now = vlib_time_now (vm);
 923   u32 thread_index = vm->thread_index;
 924   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 925   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 926     0, fragments = 0;
 927
 928   stats_node_index = sm->ed_out2in_slowpath_node_index;
 929
 930   from = vlib_frame_vector_args (frame);
 931   n_left_from = frame->n_vectors;
 932   next_index = node->cached_next_index;
 933
 934   while (n_left_from > 0)
 935     {
 936       u32 n_left_to_next;
 937
 938       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 939
 940       while (n_left_from > 0 && n_left_to_next > 0)
 941         {
 942           u32 bi0;
 943           vlib_buffer_t *b0;
 944           u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
 945             new_addr0;
 946           u16 old_port0, new_port0;
 947           ip4_header_t *ip0;
 948           udp_header_t *udp0;
 949           tcp_header_t *tcp0;
 950           icmp46_header_t *icmp0;
 951           snat_session_t *s0 = 0;
 952           clib_bihash_kv_16_8_t kv0, value0;
 953           ip_csum_t sum0;
 954           snat_session_key_t e_key0, l_key0;
 955           lb_nat_type_t lb_nat0;
 956           twice_nat_type_t twice_nat0;
 957           u8 identity_nat0;
 958
 959           /* speculatively enqueue b0 to the current next frame */
 960           bi0 = from[0];
 961           to_next[0] = bi0;
 962           from += 1;
 963           to_next += 1;
 964           n_left_from -= 1;
 965           n_left_to_next -= 1;
 966
 967           b0 = vlib_get_buffer (vm, bi0);
 968           next0 = vnet_buffer2 (b0)->nat.arc_next;
 969
 970           vnet_buffer (b0)->snat.flags = 0;
 971           ip0 = vlib_buffer_get_current (b0);
 972
 973           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 974           rx_fib_index0 =
 975             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 976                                                  sw_if_index0);
 977
 978           if (PREDICT_FALSE (ip0->ttl == 1))
 979             {
 980               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 981               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 982                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 983                                            0);
 984               next0 = NAT_NEXT_ICMP_ERROR;
 985               goto trace0;
 986             }
 987
 988           udp0 = ip4_next_header (ip0);
 989           tcp0 = (tcp_header_t *) udp0;
 990           icmp0 = (icmp46_header_t *) udp0;
 991           proto0 = ip_proto_to_snat_proto (ip0->protocol);
 992
 993           if (PREDICT_FALSE (proto0 == ~0))
 994             {
 995               s0 =
 996                 nat44_ed_out2in_unknown_proto (sm, b0, ip0, rx_fib_index0,
 997                                                thread_index, now, vm, node);
 998               if (!sm->forwarding_enabled)
 999                 {
1000                   if (!s0)
1001                     next0 = NAT_NEXT_DROP;
1002                 }
1003               other_packets++;
1004               goto trace0;
1005             }
1006
1007           if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1008             {
1009               next0 = icmp_out2in_ed_slow_path
1010                 (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1011                  next0, now, thread_index, &s0);
1012               icmp_packets++;
1013               goto trace0;
1014             }
1015
1016           make_ed_kv (&ip0->dst_address, &ip0->src_address,
1017                       ip0->protocol, rx_fib_index0,
1018                       vnet_buffer (b0)->ip.reass.l4_dst_port,
1019                       vnet_buffer (b0)->ip.reass.l4_src_port, ~0ULL, &kv0);
1020
1021           s0 = NULL;
1022           if (!clib_bihash_search_16_8 (&tsm->out2in_ed, &kv0, &value0))
1023             {
1024               s0 = pool_elt_at_index (tsm->sessions, value0.value);
1025
1026               if (s0->tcp_close_timestamp && now >= s0->tcp_close_timestamp)
1027                 {
1028                   nat_free_session_data (sm, s0, thread_index, 0);
1029                   nat44_ed_delete_session (sm, s0, thread_index, 1);
1030                   s0 = NULL;
1031                 }
1032             }
1033
1034           if (!s0)
1035             {
1036               /* Try to match static mapping by external address and port,
1037                  destination address and port in packet */
1038               e_key0.addr = ip0->dst_address;
1039               e_key0.port = vnet_buffer (b0)->ip.reass.l4_dst_port;
1040               e_key0.protocol = proto0;
1041               e_key0.fib_index = rx_fib_index0;
1042
1043               if (snat_static_mapping_match (sm, e_key0, &l_key0, 1, 0,
1044                                              &twice_nat0, &lb_nat0,
1045                                              &ip0->src_address,
1046                                              &identity_nat0))
1047                 {
1048                   /*
1049                    * Send DHCP packets to the ipv4 stack, or we won't
1050                    * be able to use dhcp client on the outside interface
1051                    */
1052                   if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_UDP
1053                                      && (vnet_buffer (b0)->ip.
1054                                          reass.l4_dst_port ==
1055                                          clib_host_to_net_u16
1056                                          (UDP_DST_PORT_dhcp_to_client))))
1057                     {
1058                       goto trace0;
1059                     }
1060
1061                   if (!sm->forwarding_enabled)
1062                     {
1063                       b0->error =
1064                         node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
1065                       next0 = NAT_NEXT_DROP;
1066                     }
1067                   else
1068                     {
1069                       if (next_src_nat
1070                           (sm, ip0, vnet_buffer (b0)->ip.reass.l4_src_port,
1071                            vnet_buffer (b0)->ip.reass.l4_dst_port,
1072                            thread_index, rx_fib_index0))
1073                         {
1074                           next0 = NAT_NEXT_IN2OUT_ED_FAST_PATH;
1075                           goto trace0;
1076                         }
1077                       if (sm->num_workers > 1)
1078                         create_bypass_for_fwd_worker (sm, b0, ip0,
1079                                                       rx_fib_index0);
1080                       else
1081                         create_bypass_for_fwd (sm, b0, ip0, rx_fib_index0,
1082                                                thread_index);
1083                     }
1084                   goto trace0;
1085                 }
1086
1087               if (PREDICT_FALSE (identity_nat0))
1088                 goto trace0;
1089
1090               if ((proto0 == SNAT_PROTOCOL_TCP)
1091                   && !tcp_flags_is_init (vnet_buffer (b0)->ip.
1092                                          reass.icmp_type_or_tcp_flags))
1093                 {
1094                   b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
1095                   next0 = NAT_NEXT_DROP;
1096                   goto trace0;
1097                 }
1098
1099               /* Create session initiated by host from external network */
1100               s0 = create_session_for_static_mapping_ed (sm, b0, l_key0,
1101                                                          e_key0, node,
1102                                                          rx_fib_index0,
1103                                                          thread_index,
1104                                                          twice_nat0,
1105                                                          lb_nat0, now);
1106               if (!s0)
1107                 {
1108                   next0 = NAT_NEXT_DROP;
1109                   goto trace0;
1110                 }
1111             }
1112
1113           old_addr0 = ip0->dst_address.as_u32;
1114           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
1115           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
1116
1117           sum0 = ip0->checksum;
1118           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1119                                  dst_address);
1120           if (PREDICT_FALSE (is_twice_nat_session (s0)))
1121             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1122                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
1123                                    src_address);
1124           ip0->checksum = ip_csum_fold (sum0);
1125
1126           old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
1127
1128           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
1129             {
1130               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1131                 {
1132                   new_port0 = udp0->dst_port = s0->in2out.port;
1133                   sum0 = tcp0->checksum;
1134                   sum0 =
1135                     ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1136                                     dst_address);
1137                   sum0 =
1138                     ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1139                                     length);
1140                   if (is_twice_nat_session (s0))
1141                     {
1142                       sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1143                                              s0->ext_host_nat_addr.as_u32,
1144                                              ip4_header_t, dst_address);
1145                       sum0 =
1146                         ip_csum_update (sum0,
1147                                         vnet_buffer (b0)->ip.
1148                                         reass.l4_src_port,
1149                                         s0->ext_host_nat_port, ip4_header_t,
1150                                         length);
1151                       tcp0->src_port = s0->ext_host_nat_port;
1152                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1153                     }
1154                   tcp0->checksum = ip_csum_fold (sum0);
1155                 }
1156               tcp_packets++;
1157               if (nat44_set_tcp_session_state_o2i
1158                   (sm, now, s0,
1159                    vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags,
1160                    vnet_buffer (b0)->ip.reass.tcp_ack_number,
1161                    vnet_buffer (b0)->ip.reass.tcp_seq_number, thread_index))
1162                 goto trace0;
1163             }
1164           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
1165                    && udp0->checksum)
1166             {
1167               new_port0 = udp0->dst_port = s0->in2out.port;
1168               sum0 = udp0->checksum;
1169               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1170                                      dst_address);
1171               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1172                                      length);
1173               if (PREDICT_FALSE (is_twice_nat_session (s0)))
1174                 {
1175                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1176                                          s0->ext_host_nat_addr.as_u32,
1177                                          ip4_header_t, dst_address);
1178                   sum0 =
1179                     ip_csum_update (sum0,
1180                                     vnet_buffer (b0)->ip.reass.l4_src_port,
1181                                     s0->ext_host_nat_port, ip4_header_t,
1182                                     length);
1183                   udp0->src_port = s0->ext_host_nat_port;
1184                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1185                 }
1186               udp0->checksum = ip_csum_fold (sum0);
1187               udp_packets++;
1188             }
1189           else
1190             {
1191               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1192                 {
1193                   new_port0 = udp0->dst_port = s0->in2out.port;
1194                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
1195                     {
1196                       udp0->src_port = s0->ext_host_nat_port;
1197                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1198                     }
1199                 }
1200               udp_packets++;
1201             }
1202
1203           /* Accounting */
1204           nat44_session_update_counters (s0, now,
1205                                          vlib_buffer_length_in_chain (vm, b0),
1206                                          thread_index);
1207           /* Per-user LRU list maintenance */
1208           nat44_session_update_lru (sm, s0, thread_index);
1209
1210         trace0:
1211           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1212                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1213             {
1214               nat44_ed_out2in_trace_t *t =
1215                 vlib_add_trace (vm, node, b0, sizeof (*t));
1216               t->sw_if_index = sw_if_index0;
1217               t->next_index = next0;
1218               t->is_slow_path = 1;
1219
1220               if (s0)
1221                 t->session_index = s0 - tsm->sessions;
1222               else
1223                 t->session_index = ~0;
1224             }
1225
1226           pkts_processed += next0 == vnet_buffer2 (b0)->nat.arc_next;
1227           /* verify speculative enqueue, maybe switch current next frame */
1228           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1229                                            to_next, n_left_to_next,
1230                                            bi0, next0);
1231         }
1232
1233       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1234     }
1235
1236   vlib_node_increment_counter (vm, stats_node_index,
1237                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
1238                                pkts_processed);
1239   vlib_node_increment_counter (vm, stats_node_index,
1240                                NAT_OUT2IN_ED_ERROR_TCP_PACKETS, tcp_packets);
1241   vlib_node_increment_counter (vm, stats_node_index,
1242                                NAT_OUT2IN_ED_ERROR_UDP_PACKETS, udp_packets);
1243   vlib_node_increment_counter (vm, stats_node_index,
1244                                NAT_OUT2IN_ED_ERROR_ICMP_PACKETS,
1245                                icmp_packets);
1246   vlib_node_increment_counter (vm, stats_node_index,
1247                                NAT_OUT2IN_ED_ERROR_OTHER_PACKETS,
1248                                other_packets);
1249   vlib_node_increment_counter (vm, stats_node_index,
1250                                NAT_OUT2IN_ED_ERROR_FRAGMENTS, fragments);
1251   return frame->n_vectors;
1252 }
1253
1254 VLIB_NODE_FN (nat44_ed_out2in_node) (vlib_main_t * vm,
1255                                      vlib_node_runtime_t * node,
1256                                      vlib_frame_t * frame)
1257 {
1258   return nat44_ed_out2in_fast_path_node_fn_inline (vm, node, frame);
1259 }
1260
1261 /* *INDENT-OFF* */
1262 VLIB_REGISTER_NODE (nat44_ed_out2in_node) = {
1263   .name = "nat44-ed-out2in",
1264   .vector_size = sizeof (u32),
1265   .sibling_of = "nat-default",
1266   .format_trace = format_nat44_ed_out2in_trace,
1267   .type = VLIB_NODE_TYPE_INTERNAL,
1268   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1269   .error_strings = nat_out2in_ed_error_strings,
1270   .runtime_data_bytes = sizeof (snat_runtime_t),
1271 };
1272 /* *INDENT-ON* */
1273
1274 VLIB_NODE_FN (nat44_ed_out2in_slowpath_node) (vlib_main_t * vm,
1275                                               vlib_node_runtime_t * node,
1276                                               vlib_frame_t * frame)
1277 {
1278   return nat44_ed_out2in_slow_path_node_fn_inline (vm, node, frame);
1279 }
1280
1281 /* *INDENT-OFF* */
1282 VLIB_REGISTER_NODE (nat44_ed_out2in_slowpath_node) = {
1283   .name = "nat44-ed-out2in-slowpath",
1284   .vector_size = sizeof (u32),
1285   .sibling_of = "nat-default",
1286   .format_trace = format_nat44_ed_out2in_trace,
1287   .type = VLIB_NODE_TYPE_INTERNAL,
1288   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1289   .error_strings = nat_out2in_ed_error_strings,
1290   .runtime_data_bytes = sizeof (snat_runtime_t),
1291 };
1292 /* *INDENT-ON* */
1293
1294 static u8 *
1295 format_nat_pre_trace (u8 * s, va_list * args)
1296 {
1297   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1298   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1299   nat_pre_trace_t *t = va_arg (*args, nat_pre_trace_t *);
1300   return format (s, "out2in next_index %d arc_next_index %d", t->next_index,
1301                  t->arc_next_index);
1302 }
1303
1304 VLIB_NODE_FN (nat_pre_out2in_node) (vlib_main_t * vm,
1305                                     vlib_node_runtime_t * node,
1306                                     vlib_frame_t * frame)
1307 {
1308   return nat_pre_node_fn_inline (vm, node, frame,
1309                                  NAT_NEXT_OUT2IN_ED_FAST_PATH);
1310 }
1311
1312 /* *INDENT-OFF* */
1313 VLIB_REGISTER_NODE (nat_pre_out2in_node) = {
1314   .name = "nat-pre-out2in",
1315   .vector_size = sizeof (u32),
1316   .sibling_of = "nat-default",
1317   .format_trace = format_nat_pre_trace,
1318   .type = VLIB_NODE_TYPE_INTERNAL,
1319   .n_errors = 0,
1320  };
1321 /* *INDENT-ON* */
1322
1323 /*
1324  * fd.io coding-style-patch-verification: ON
1325  *
1326  * Local Variables:
1327  * eval: (c-set-style "gnu")
1328  * End:
1329  */