src/plugins/nat/out2in_ed.c

   1 /*
   2  * Copyright (c) 2018 Cisco and/or its affiliates.
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15 /**
  16  * @file
  17  * @brief NAT44 endpoint-dependent outside to inside network translation
  18  */
  19
  20 #include <vlib/vlib.h>
  21 #include <vnet/vnet.h>
  22 #include <vnet/pg/pg.h>
  23 #include <vnet/ip/ip.h>
  24 #include <vnet/ethernet/ethernet.h>
  25 #include <vnet/fib/ip4_fib.h>
  26 #include <vnet/udp/udp.h>
  27 #include <vppinfra/error.h>
  28 #include <nat/nat.h>
  29 #include <nat/nat_ipfix_logging.h>
  30 #include <nat/nat_inlines.h>
  31 #include <nat/nat44/inlines.h>
  32 #include <nat/nat_syslog.h>
  33 #include <nat/nat_ha.h>
  34
  35 static char *nat_out2in_ed_error_strings[] = {
  36 #define _(sym,string) string,
  37   foreach_nat_out2in_ed_error
  38 #undef _
  39 };
  40
  41 typedef struct
  42 {
  43   u32 sw_if_index;
  44   u32 next_index;
  45   u32 session_index;
  46   u32 is_slow_path;
  47 } nat44_ed_out2in_trace_t;
  48
  49 static u8 *
  50 format_nat44_ed_out2in_trace (u8 * s, va_list * args)
  51 {
  52   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  53   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  54   nat44_ed_out2in_trace_t *t = va_arg (*args, nat44_ed_out2in_trace_t *);
  55   char *tag;
  56
  57   tag =
  58     t->is_slow_path ? "NAT44_OUT2IN_ED_SLOW_PATH" :
  59     "NAT44_OUT2IN_ED_FAST_PATH";
  60
  61   s = format (s, "%s: sw_if_index %d, next index %d, session %d", tag,
  62               t->sw_if_index, t->next_index, t->session_index);
  63
  64   return s;
  65 }
  66
  67 static inline u32
  68 icmp_out2in_ed_slow_path (snat_main_t * sm, vlib_buffer_t * b0,
  69                           ip4_header_t * ip0, icmp46_header_t * icmp0,
  70                           u32 sw_if_index0, u32 rx_fib_index0,
  71                           vlib_node_runtime_t * node, u32 next0, f64 now,
  72                           u32 thread_index, snat_session_t ** p_s0)
  73 {
  74   next0 = icmp_out2in (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
  75                        next0, thread_index, p_s0, 0);
  76   snat_session_t *s0 = *p_s0;
  77   if (PREDICT_TRUE (next0 != NAT_NEXT_DROP && s0))
  78     {
  79       /* Accounting */
  80       nat44_session_update_counters (s0, now,
  81                                      vlib_buffer_length_in_chain
  82                                      (sm->vlib_main, b0), thread_index);
  83       /* Per-user LRU list maintenance */
  84       nat44_session_update_lru (sm, s0, thread_index);
  85     }
  86   return next0;
  87 }
  88
  89 #ifndef CLIB_MARCH_VARIANT
  90 int
  91 nat44_o2i_ed_is_idle_session_cb (clib_bihash_kv_16_8_t * kv, void *arg)
  92 {
  93   snat_main_t *sm = &snat_main;
  94   nat44_is_idle_session_ctx_t *ctx = arg;
  95   snat_session_t *s;
  96   u64 sess_timeout_time;
  97   nat_ed_ses_key_t ed_key;
  98   clib_bihash_kv_16_8_t ed_kv;
  99   int i;
 100   snat_address_t *a;
 101   snat_session_key_t key;
 102   snat_main_per_thread_data_t *tsm = vec_elt_at_index (sm->per_thread_data,
 103                                                        ctx->thread_index);
 104
 105   s = pool_elt_at_index (tsm->sessions, kv->value);
 106   sess_timeout_time = s->last_heard + (f64) nat44_session_get_timeout (sm, s);
 107   if (ctx->now >= sess_timeout_time)
 108     {
 109       ed_key.l_addr = s->in2out.addr;
 110       ed_key.r_addr = s->ext_host_addr;
 111       ed_key.fib_index = s->in2out.fib_index;
 112       if (snat_is_unk_proto_session (s))
 113         {
 114           ed_key.proto = s->in2out.port;
 115           ed_key.r_port = 0;
 116           ed_key.l_port = 0;
 117         }
 118       else
 119         {
 120           ed_key.proto = snat_proto_to_ip_proto (s->in2out.protocol);
 121           ed_key.l_port = s->in2out.port;
 122           ed_key.r_port = s->ext_host_port;
 123         }
 124       if (is_twice_nat_session (s))
 125         {
 126           ed_key.r_addr = s->ext_host_nat_addr;
 127           ed_key.r_port = s->ext_host_nat_port;
 128         }
 129       ed_kv.key[0] = ed_key.as_u64[0];
 130       ed_kv.key[1] = ed_key.as_u64[1];
 131       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &ed_kv, 0))
 132         nat_elog_warn ("in2out_ed key del failed");
 133
 134       if (snat_is_unk_proto_session (s))
 135         goto delete;
 136
 137       snat_ipfix_logging_nat44_ses_delete (ctx->thread_index,
 138                                            s->in2out.addr.as_u32,
 139                                            s->out2in.addr.as_u32,
 140                                            s->in2out.protocol,
 141                                            s->in2out.port,
 142                                            s->out2in.port,
 143                                            s->in2out.fib_index);
 144
 145       nat_syslog_nat44_sdel (s->user_index, s->in2out.fib_index,
 146                              &s->in2out.addr, s->in2out.port,
 147                              &s->ext_host_nat_addr, s->ext_host_nat_port,
 148                              &s->out2in.addr, s->out2in.port,
 149                              &s->ext_host_addr, s->ext_host_port,
 150                              s->in2out.protocol, is_twice_nat_session (s));
 151
 152       nat_ha_sdel (&s->out2in.addr, s->out2in.port, &s->ext_host_addr,
 153                    s->ext_host_port, s->out2in.protocol, s->out2in.fib_index,
 154                    ctx->thread_index);
 155
 156       if (is_twice_nat_session (s))
 157         {
 158           for (i = 0; i < vec_len (sm->twice_nat_addresses); i++)
 159             {
 160               key.protocol = s->in2out.protocol;
 161               key.port = s->ext_host_nat_port;
 162               a = sm->twice_nat_addresses + i;
 163               if (a->addr.as_u32 == s->ext_host_nat_addr.as_u32)
 164                 {
 165                   snat_free_outside_address_and_port (sm->twice_nat_addresses,
 166                                                       ctx->thread_index,
 167                                                       &key);
 168                   break;
 169                 }
 170             }
 171         }
 172
 173       if (snat_is_session_static (s))
 174         goto delete;
 175
 176       snat_free_outside_address_and_port (sm->addresses, ctx->thread_index,
 177                                           &s->out2in);
 178     delete:
 179       nat44_ed_delete_session (sm, s, ctx->thread_index, 1);
 180       return 1;
 181     }
 182
 183   return 0;
 184 }
 185 #endif
 186
 187 static snat_session_t *
 188 create_session_for_static_mapping_ed (snat_main_t * sm,
 189                                       vlib_buffer_t * b,
 190                                       snat_session_key_t l_key,
 191                                       snat_session_key_t e_key,
 192                                       vlib_node_runtime_t * node,
 193                                       u32 thread_index,
 194                                       twice_nat_type_t twice_nat,
 195                                       lb_nat_type_t lb_nat, f64 now)
 196 {
 197   snat_session_t *s;
 198   ip4_header_t *ip;
 199   udp_header_t *udp;
 200   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 201   clib_bihash_kv_16_8_t kv;
 202   snat_session_key_t eh_key;
 203   nat44_is_idle_session_ctx_t ctx;
 204
 205   if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
 206     {
 207       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 208       nat_elog_notice ("maximum sessions exceeded");
 209       return 0;
 210     }
 211
 212   s = nat_ed_session_alloc (sm, thread_index, now);
 213   if (!s)
 214     {
 215       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_USER_SESS_EXCEEDED];
 216       nat_elog_warn ("create NAT session failed");
 217       return 0;
 218     }
 219
 220   ip = vlib_buffer_get_current (b);
 221   udp = ip4_next_header (ip);
 222
 223   s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 224   s->ext_host_port = e_key.protocol == SNAT_PROTOCOL_ICMP ? 0 : udp->src_port;
 225   s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 226   if (lb_nat)
 227     s->flags |= SNAT_SESSION_FLAG_LOAD_BALANCING;
 228   if (lb_nat == AFFINITY_LB_NAT)
 229     s->flags |= SNAT_SESSION_FLAG_AFFINITY;
 230   s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 231   s->out2in = e_key;
 232   s->in2out = l_key;
 233   s->in2out.protocol = s->out2in.protocol;
 234
 235   /* Add to lookup tables */
 236   make_ed_kv (&kv, &e_key.addr, &s->ext_host_addr, ip->protocol,
 237               e_key.fib_index, e_key.port, s->ext_host_port);
 238   kv.value = s - tsm->sessions;
 239   ctx.now = now;
 240   ctx.thread_index = thread_index;
 241   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->out2in_ed, &kv,
 242                                                nat44_o2i_ed_is_idle_session_cb,
 243                                                &ctx))
 244     nat_elog_notice ("out2in-ed key add failed");
 245
 246   if (twice_nat == TWICE_NAT || (twice_nat == TWICE_NAT_SELF &&
 247                                  ip->src_address.as_u32 == l_key.addr.as_u32))
 248     {
 249       eh_key.protocol = e_key.protocol;
 250       if (snat_alloc_outside_address_and_port (sm->twice_nat_addresses, 0,
 251                                                thread_index, &eh_key,
 252                                                sm->port_per_thread,
 253                                                tsm->snat_thread_index))
 254         {
 255           b->error = node->errors[NAT_OUT2IN_ED_ERROR_OUT_OF_PORTS];
 256           nat44_ed_delete_session (sm, s, thread_index, 1);
 257           if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &kv, 0))
 258             nat_elog_notice ("out2in-ed key del failed");
 259           return 0;
 260         }
 261       s->ext_host_nat_addr.as_u32 = eh_key.addr.as_u32;
 262       s->ext_host_nat_port = eh_key.port;
 263       s->flags |= SNAT_SESSION_FLAG_TWICE_NAT;
 264       make_ed_kv (&kv, &l_key.addr, &s->ext_host_nat_addr, ip->protocol,
 265                   l_key.fib_index, l_key.port, s->ext_host_nat_port);
 266     }
 267   else
 268     {
 269       make_ed_kv (&kv, &l_key.addr, &s->ext_host_addr, ip->protocol,
 270                   l_key.fib_index, l_key.port, s->ext_host_port);
 271     }
 272   kv.value = s - tsm->sessions;
 273   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->in2out_ed, &kv,
 274                                                nat44_i2o_ed_is_idle_session_cb,
 275                                                &ctx))
 276     nat_elog_notice ("in2out-ed key add failed");
 277
 278   snat_ipfix_logging_nat44_ses_create (thread_index,
 279                                        s->in2out.addr.as_u32,
 280                                        s->out2in.addr.as_u32,
 281                                        s->in2out.protocol,
 282                                        s->in2out.port,
 283                                        s->out2in.port, s->in2out.fib_index);
 284
 285   nat_syslog_nat44_sadd (s->user_index, s->in2out.fib_index,
 286                          &s->in2out.addr, s->in2out.port,
 287                          &s->ext_host_nat_addr, s->ext_host_nat_port,
 288                          &s->out2in.addr, s->out2in.port,
 289                          &s->ext_host_addr, s->ext_host_port,
 290                          s->in2out.protocol, is_twice_nat_session (s));
 291
 292   nat_ha_sadd (&s->in2out.addr, s->in2out.port, &s->out2in.addr,
 293                s->out2in.port, &s->ext_host_addr, s->ext_host_port,
 294                &s->ext_host_nat_addr, s->ext_host_nat_port,
 295                s->in2out.protocol, s->in2out.fib_index, s->flags,
 296                thread_index, 0);
 297
 298   return s;
 299 }
 300
 301 static int
 302 next_src_nat (snat_main_t * sm, ip4_header_t * ip, u8 proto, u16 src_port,
 303               u16 dst_port, u32 thread_index, u32 rx_fib_index)
 304 {
 305   clib_bihash_kv_16_8_t kv, value;
 306   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 307
 308   make_ed_kv (&kv, &ip->src_address, &ip->dst_address, proto,
 309               rx_fib_index, src_port, dst_port);
 310   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 311     return 1;
 312
 313   return 0;
 314 }
 315
 316 static void
 317 create_bypass_for_fwd (snat_main_t * sm, vlib_buffer_t * b, ip4_header_t * ip,
 318                        u32 rx_fib_index, u32 thread_index)
 319 {
 320   nat_ed_ses_key_t key;
 321   clib_bihash_kv_16_8_t kv, value;
 322   udp_header_t *udp;
 323   snat_session_t *s = 0;
 324   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 325   f64 now = vlib_time_now (sm->vlib_main);
 326
 327   if (ip->protocol == IP_PROTOCOL_ICMP)
 328     {
 329       if (get_icmp_o2i_ed_key (b, ip, &key))
 330         return;
 331     }
 332   else if (ip->protocol == IP_PROTOCOL_UDP || ip->protocol == IP_PROTOCOL_TCP)
 333     {
 334       udp = ip4_next_header (ip);
 335       key.r_addr = ip->src_address;
 336       key.l_addr = ip->dst_address;
 337       key.proto = ip->protocol;
 338       key.l_port = udp->dst_port;
 339       key.r_port = udp->src_port;
 340     }
 341   else
 342     {
 343       key.r_addr = ip->src_address;
 344       key.l_addr = ip->dst_address;
 345       key.proto = ip->protocol;
 346       key.l_port = key.r_port = 0;
 347     }
 348   key.fib_index = 0;
 349   kv.key[0] = key.as_u64[0];
 350   kv.key[1] = key.as_u64[1];
 351
 352   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 353     {
 354       s = pool_elt_at_index (tsm->sessions, value.value);
 355     }
 356   else
 357     {
 358       u32 proto;
 359
 360       if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
 361         return;
 362
 363       s = nat_ed_session_alloc (sm, thread_index, now);
 364       if (!s)
 365         {
 366           nat_elog_warn ("create NAT session failed");
 367           return;
 368         }
 369
 370       proto = ip_proto_to_snat_proto (key.proto);
 371
 372       s->ext_host_addr = key.r_addr;
 373       s->ext_host_port = key.r_port;
 374       s->flags |= SNAT_SESSION_FLAG_FWD_BYPASS;
 375       s->out2in.addr = key.l_addr;
 376       s->out2in.port = key.l_port;
 377       s->out2in.protocol = proto;
 378       if (proto == ~0)
 379         {
 380           s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 381           s->out2in.port = ip->protocol;
 382         }
 383       s->out2in.fib_index = 0;
 384       s->in2out = s->out2in;
 385
 386       kv.value = s - tsm->sessions;
 387       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &kv, 1))
 388         nat_elog_notice ("in2out_ed key add failed");
 389     }
 390
 391   if (ip->protocol == IP_PROTOCOL_TCP)
 392     {
 393       tcp_header_t *tcp = ip4_next_header (ip);
 394       if (nat44_set_tcp_session_state_o2i
 395           (sm, now, s, tcp->flags, tcp->ack_number, tcp->seq_number,
 396            thread_index))
 397         return;
 398     }
 399
 400   /* Accounting */
 401   nat44_session_update_counters (s, now, 0, thread_index);
 402   /* Per-user LRU list maintenance */
 403   nat44_session_update_lru (sm, s, thread_index);
 404 }
 405
 406 static inline void
 407 create_bypass_for_fwd_worker (snat_main_t * sm, vlib_buffer_t * b,
 408                               ip4_header_t * ip, u32 rx_fib_index)
 409 {
 410   ip4_header_t ip_wkr = {
 411     .src_address = ip->dst_address,
 412   };
 413   u32 thread_index = sm->worker_in2out_cb (&ip_wkr, rx_fib_index, 0);
 414
 415   create_bypass_for_fwd (sm, b, ip, rx_fib_index, thread_index);
 416 }
 417
 418 #ifndef CLIB_MARCH_VARIANT
 419 u32
 420 icmp_match_out2in_ed (snat_main_t * sm, vlib_node_runtime_t * node,
 421                       u32 thread_index, vlib_buffer_t * b, ip4_header_t * ip,
 422                       u8 * p_proto, snat_session_key_t * p_value,
 423                       u8 * p_dont_translate, void *d, void *e)
 424 {
 425   u32 next = ~0, sw_if_index, rx_fib_index;
 426   nat_ed_ses_key_t key;
 427   clib_bihash_kv_16_8_t kv, value;
 428   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 429   snat_session_t *s = 0;
 430   u8 dont_translate = 0, is_addr_only, identity_nat;
 431   snat_session_key_t e_key, l_key;
 432
 433   sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
 434   rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 435
 436   if (get_icmp_o2i_ed_key (b, ip, &key))
 437     {
 438       b->error = node->errors[NAT_OUT2IN_ED_ERROR_UNSUPPORTED_PROTOCOL];
 439       next = NAT_NEXT_DROP;
 440       goto out;
 441     }
 442   key.fib_index = rx_fib_index;
 443   kv.key[0] = key.as_u64[0];
 444   kv.key[1] = key.as_u64[1];
 445
 446   if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv, &value))
 447     {
 448       /* Try to match static mapping */
 449       e_key.addr = ip->dst_address;
 450       e_key.port = key.l_port;
 451       e_key.protocol = ip_proto_to_snat_proto (key.proto);
 452       e_key.fib_index = rx_fib_index;
 453       if (snat_static_mapping_match
 454           (sm, e_key, &l_key, 1, &is_addr_only, 0, 0, 0, &identity_nat))
 455         {
 456           if (!sm->forwarding_enabled)
 457             {
 458               /* Don't NAT packet aimed at the intfc address */
 459               if (PREDICT_FALSE (is_interface_addr (sm, node, sw_if_index,
 460                                                     ip->dst_address.as_u32)))
 461                 {
 462                   dont_translate = 1;
 463                   goto out;
 464                 }
 465               b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 466               next = NAT_NEXT_DROP;
 467               goto out;
 468             }
 469           else
 470             {
 471               dont_translate = 1;
 472               if (next_src_nat (sm, ip, key.proto, key.l_port, key.r_port,
 473                                 thread_index, rx_fib_index))
 474                 {
 475                   next = NAT_NEXT_IN2OUT_ED_FAST_PATH;
 476                   goto out;
 477                 }
 478               if (sm->num_workers > 1)
 479                 create_bypass_for_fwd_worker (sm, b, ip, rx_fib_index);
 480               else
 481                 create_bypass_for_fwd (sm, b, ip, rx_fib_index, thread_index);
 482               goto out;
 483             }
 484         }
 485
 486       if (PREDICT_FALSE
 487           (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 488            ICMP4_echo_reply
 489            && (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 490                ICMP4_echo_request || !is_addr_only)))
 491         {
 492           b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 493           next = NAT_NEXT_DROP;
 494           goto out;
 495         }
 496
 497       if (PREDICT_FALSE (identity_nat))
 498         {
 499           dont_translate = 1;
 500           goto out;
 501         }
 502
 503       /* Create session initiated by host from external network */
 504       s = create_session_for_static_mapping_ed (sm, b, l_key, e_key, node,
 505                                                 thread_index, 0, 0,
 506                                                 vlib_time_now
 507                                                 (sm->vlib_main));
 508
 509       if (!s)
 510         {
 511           next = NAT_NEXT_DROP;
 512           goto out;
 513         }
 514     }
 515   else
 516     {
 517       if (PREDICT_FALSE
 518           (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 519            ICMP4_echo_reply
 520            && vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 521            ICMP4_echo_request
 522            && !icmp_type_is_error_message (vnet_buffer (b)->ip.
 523                                            reass.icmp_type_or_tcp_flags)))
 524         {
 525           b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 526           next = NAT_NEXT_DROP;
 527           goto out;
 528         }
 529
 530       s = pool_elt_at_index (tsm->sessions, value.value);
 531     }
 532
 533   *p_proto = ip_proto_to_snat_proto (key.proto);
 534 out:
 535   if (s)
 536     *p_value = s->in2out;
 537   *p_dont_translate = dont_translate;
 538   if (d)
 539     *(snat_session_t **) d = s;
 540   return next;
 541 }
 542 #endif
 543
 544 static snat_session_t *
 545 nat44_ed_out2in_unknown_proto (snat_main_t * sm,
 546                                vlib_buffer_t * b,
 547                                ip4_header_t * ip,
 548                                u32 rx_fib_index,
 549                                u32 thread_index,
 550                                f64 now,
 551                                vlib_main_t * vm, vlib_node_runtime_t * node)
 552 {
 553   clib_bihash_kv_8_8_t kv, value;
 554   clib_bihash_kv_16_8_t s_kv, s_value;
 555   snat_static_mapping_t *m;
 556   u32 old_addr, new_addr;
 557   ip_csum_t sum;
 558   snat_session_t *s;
 559   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 560
 561   old_addr = ip->dst_address.as_u32;
 562
 563   make_ed_kv (&s_kv, &ip->dst_address, &ip->src_address, ip->protocol,
 564               rx_fib_index, 0, 0);
 565
 566   if (!clib_bihash_search_16_8 (&tsm->out2in_ed, &s_kv, &s_value))
 567     {
 568       s = pool_elt_at_index (tsm->sessions, s_value.value);
 569       new_addr = ip->dst_address.as_u32 = s->in2out.addr.as_u32;
 570     }
 571   else
 572     {
 573       if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
 574         {
 575           b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 576           nat_elog_notice ("maximum sessions exceeded");
 577           return 0;
 578         }
 579
 580       make_sm_kv (&kv, &ip->dst_address, 0, 0, 0);
 581       if (clib_bihash_search_8_8
 582           (&sm->static_mapping_by_external, &kv, &value))
 583         {
 584           b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 585           return 0;
 586         }
 587
 588       m = pool_elt_at_index (sm->static_mappings, value.value);
 589
 590       new_addr = ip->dst_address.as_u32 = m->local_addr.as_u32;
 591
 592       /* Create a new session */
 593       s = nat_ed_session_alloc (sm, thread_index, now);
 594       if (!s)
 595         {
 596           b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_USER_SESS_EXCEEDED];
 597           nat_elog_warn ("create NAT session failed");
 598           return 0;
 599         }
 600
 601       s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 602       s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 603       s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 604       s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 605       s->out2in.addr.as_u32 = old_addr;
 606       s->out2in.fib_index = rx_fib_index;
 607       s->in2out.addr.as_u32 = new_addr;
 608       s->in2out.fib_index = m->fib_index;
 609       s->in2out.port = s->out2in.port = ip->protocol;
 610
 611       /* Add to lookup tables */
 612       s_kv.value = s - tsm->sessions;
 613       if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &s_kv, 1))
 614         nat_elog_notice ("out2in key add failed");
 615
 616       make_ed_kv (&s_kv, &ip->dst_address, &ip->src_address, ip->protocol,
 617                   m->fib_index, 0, 0);
 618       s_kv.value = s - tsm->sessions;
 619       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &s_kv, 1))
 620         nat_elog_notice ("in2out key add failed");
 621     }
 622
 623   /* Update IP checksum */
 624   sum = ip->checksum;
 625   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
 626   ip->checksum = ip_csum_fold (sum);
 627
 628   vnet_buffer (b)->sw_if_index[VLIB_TX] = s->in2out.fib_index;
 629
 630   /* Accounting */
 631   nat44_session_update_counters (s, now, vlib_buffer_length_in_chain (vm, b),
 632                                  thread_index);
 633   /* Per-user LRU list maintenance */
 634   nat44_session_update_lru (sm, s, thread_index);
 635
 636   return s;
 637 }
 638
 639 static inline uword
 640 nat44_ed_out2in_fast_path_node_fn_inline (vlib_main_t * vm,
 641                                           vlib_node_runtime_t * node,
 642                                           vlib_frame_t * frame)
 643 {
 644   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
 645   nat_next_t next_index;
 646   snat_main_t *sm = &snat_main;
 647   f64 now = vlib_time_now (vm);
 648   u32 thread_index = vm->thread_index;
 649   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 650   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 651     0, fragments = 0;
 652
 653   stats_node_index = sm->ed_out2in_node_index;
 654
 655   from = vlib_frame_vector_args (frame);
 656   n_left_from = frame->n_vectors;
 657   next_index = node->cached_next_index;
 658
 659   while (n_left_from > 0)
 660     {
 661       u32 n_left_to_next;
 662
 663       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 664
 665       while (n_left_from > 0 && n_left_to_next > 0)
 666         {
 667           u32 bi0;
 668           vlib_buffer_t *b0;
 669           u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
 670             new_addr0;
 671           u16 old_port0, new_port0;
 672           ip4_header_t *ip0;
 673           udp_header_t *udp0;
 674           tcp_header_t *tcp0;
 675           snat_session_t *s0 = 0;
 676           clib_bihash_kv_16_8_t kv0, value0;
 677           ip_csum_t sum0;
 678
 679           /* speculatively enqueue b0 to the current next frame */
 680           bi0 = from[0];
 681           to_next[0] = bi0;
 682           from += 1;
 683           to_next += 1;
 684           n_left_from -= 1;
 685           n_left_to_next -= 1;
 686
 687           b0 = vlib_get_buffer (vm, bi0);
 688           next0 = vnet_buffer2 (b0)->nat.arc_next;
 689
 690           vnet_buffer (b0)->snat.flags = 0;
 691           ip0 = vlib_buffer_get_current (b0);
 692
 693           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 694           rx_fib_index0 =
 695             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 696                                                  sw_if_index0);
 697
 698           if (PREDICT_FALSE (ip0->ttl == 1))
 699             {
 700               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 701               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 702                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 703                                            0);
 704               next0 = NAT_NEXT_ICMP_ERROR;
 705               goto trace0;
 706             }
 707
 708           udp0 = ip4_next_header (ip0);
 709           tcp0 = (tcp_header_t *) udp0;
 710           proto0 = ip_proto_to_snat_proto (ip0->protocol);
 711
 712           if (PREDICT_FALSE (proto0 == ~0))
 713             {
 714               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 715               goto trace0;
 716             }
 717
 718           if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
 719             {
 720               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 721               goto trace0;
 722             }
 723
 724           make_ed_kv (&kv0, &ip0->dst_address, &ip0->src_address,
 725                       ip0->protocol, rx_fib_index0,
 726                       vnet_buffer (b0)->ip.reass.l4_dst_port,
 727                       vnet_buffer (b0)->ip.reass.l4_src_port);
 728
 729           if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv0, &value0))
 730             {
 731               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 732               goto trace0;
 733             }
 734           s0 = pool_elt_at_index (tsm->sessions, value0.value);
 735
 736           if (s0->tcp_close_timestamp)
 737             {
 738               if (now >= s0->tcp_close_timestamp)
 739                 {
 740                   // session is closed, go slow path
 741                   next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 742                 }
 743               else
 744                 {
 745                   // session in transitory timeout, drop
 746                   b0->error = node->errors[NAT_OUT2IN_ED_ERROR_TCP_CLOSED];
 747                   next0 = NAT_NEXT_DROP;
 748                 }
 749               goto trace0;
 750             }
 751
 752           // drop if session expired
 753           u64 sess_timeout_time;
 754           sess_timeout_time = s0->last_heard +
 755             (f64) nat44_session_get_timeout (sm, s0);
 756           if (now >= sess_timeout_time)
 757             {
 758               // session is closed, go slow path
 759               nat_free_session_data (sm, s0, thread_index, 0);
 760               nat44_ed_delete_session (sm, s0, thread_index, 1);
 761               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 762               goto trace0;
 763             }
 764           //
 765
 766           old_addr0 = ip0->dst_address.as_u32;
 767           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
 768           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
 769
 770           sum0 = ip0->checksum;
 771           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 772                                  dst_address);
 773           if (PREDICT_FALSE (is_twice_nat_session (s0)))
 774             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 775                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
 776                                    src_address);
 777           ip0->checksum = ip_csum_fold (sum0);
 778
 779           old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
 780
 781           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
 782             {
 783               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 784                 {
 785                   new_port0 = udp0->dst_port = s0->in2out.port;
 786                   sum0 = tcp0->checksum;
 787                   sum0 =
 788                     ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 789                                     dst_address);
 790                   sum0 =
 791                     ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 792                                     length);
 793                   if (is_twice_nat_session (s0))
 794                     {
 795                       sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 796                                              s0->ext_host_nat_addr.as_u32,
 797                                              ip4_header_t, dst_address);
 798                       sum0 =
 799                         ip_csum_update (sum0,
 800                                         vnet_buffer (b0)->ip.
 801                                         reass.l4_src_port,
 802                                         s0->ext_host_nat_port, ip4_header_t,
 803                                         length);
 804                       tcp0->src_port = s0->ext_host_nat_port;
 805                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 806                     }
 807                   tcp0->checksum = ip_csum_fold (sum0);
 808                 }
 809               tcp_packets++;
 810               if (nat44_set_tcp_session_state_o2i
 811                   (sm, now, s0,
 812                    vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags,
 813                    vnet_buffer (b0)->ip.reass.tcp_ack_number,
 814                    vnet_buffer (b0)->ip.reass.tcp_seq_number, thread_index))
 815                 goto trace0;
 816             }
 817           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
 818                    && udp0->checksum)
 819             {
 820               new_port0 = udp0->dst_port = s0->in2out.port;
 821               sum0 = udp0->checksum;
 822               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 823                                      dst_address);
 824               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 825                                      length);
 826               if (PREDICT_FALSE (is_twice_nat_session (s0)))
 827                 {
 828                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 829                                          s0->ext_host_nat_addr.as_u32,
 830                                          ip4_header_t, dst_address);
 831                   sum0 =
 832                     ip_csum_update (sum0,
 833                                     vnet_buffer (b0)->ip.reass.l4_src_port,
 834                                     s0->ext_host_nat_port, ip4_header_t,
 835                                     length);
 836                   udp0->src_port = s0->ext_host_nat_port;
 837                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 838                 }
 839               udp0->checksum = ip_csum_fold (sum0);
 840               udp_packets++;
 841             }
 842           else
 843             {
 844               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 845                 {
 846                   new_port0 = udp0->dst_port = s0->in2out.port;
 847                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
 848                     {
 849                       udp0->src_port = s0->ext_host_nat_port;
 850                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 851                     }
 852                 }
 853               udp_packets++;
 854             }
 855
 856           /* Accounting */
 857           nat44_session_update_counters (s0, now,
 858                                          vlib_buffer_length_in_chain (vm, b0),
 859                                          thread_index);
 860           /* Per-user LRU list maintenance */
 861           nat44_session_update_lru (sm, s0, thread_index);
 862
 863         trace0:
 864           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 865                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 866             {
 867               nat44_ed_out2in_trace_t *t =
 868                 vlib_add_trace (vm, node, b0, sizeof (*t));
 869               t->sw_if_index = sw_if_index0;
 870               t->next_index = next0;
 871               t->is_slow_path = 0;
 872
 873               if (s0)
 874                 t->session_index = s0 - tsm->sessions;
 875               else
 876                 t->session_index = ~0;
 877             }
 878
 879           pkts_processed += next0 == vnet_buffer2 (b0)->nat.arc_next;
 880           /* verify speculative enqueue, maybe switch current next frame */
 881           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 882                                            to_next, n_left_to_next,
 883                                            bi0, next0);
 884         }
 885
 886       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 887     }
 888
 889   vlib_node_increment_counter (vm, stats_node_index,
 890                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
 891                                pkts_processed);
 892   vlib_node_increment_counter (vm, stats_node_index,
 893                                NAT_OUT2IN_ED_ERROR_TCP_PACKETS, tcp_packets);
 894   vlib_node_increment_counter (vm, stats_node_index,
 895                                NAT_OUT2IN_ED_ERROR_UDP_PACKETS, udp_packets);
 896   vlib_node_increment_counter (vm, stats_node_index,
 897                                NAT_OUT2IN_ED_ERROR_ICMP_PACKETS,
 898                                icmp_packets);
 899   vlib_node_increment_counter (vm, stats_node_index,
 900                                NAT_OUT2IN_ED_ERROR_OTHER_PACKETS,
 901                                other_packets);
 902   vlib_node_increment_counter (vm, stats_node_index,
 903                                NAT_OUT2IN_ED_ERROR_FRAGMENTS, fragments);
 904   return frame->n_vectors;
 905 }
 906
 907 static inline uword
 908 nat44_ed_out2in_slow_path_node_fn_inline (vlib_main_t * vm,
 909                                           vlib_node_runtime_t * node,
 910                                           vlib_frame_t * frame)
 911 {
 912   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
 913   nat_next_t next_index;
 914   snat_main_t *sm = &snat_main;
 915   f64 now = vlib_time_now (vm);
 916   u32 thread_index = vm->thread_index;
 917   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 918   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 919     0, fragments = 0;
 920
 921   stats_node_index = sm->ed_out2in_slowpath_node_index;
 922
 923   from = vlib_frame_vector_args (frame);
 924   n_left_from = frame->n_vectors;
 925   next_index = node->cached_next_index;
 926
 927   while (n_left_from > 0)
 928     {
 929       u32 n_left_to_next;
 930
 931       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 932
 933       while (n_left_from > 0 && n_left_to_next > 0)
 934         {
 935           u32 bi0;
 936           vlib_buffer_t *b0;
 937           u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
 938             new_addr0;
 939           u16 old_port0, new_port0;
 940           ip4_header_t *ip0;
 941           udp_header_t *udp0;
 942           tcp_header_t *tcp0;
 943           icmp46_header_t *icmp0;
 944           snat_session_t *s0 = 0;
 945           clib_bihash_kv_16_8_t kv0, value0;
 946           ip_csum_t sum0;
 947           snat_session_key_t e_key0, l_key0;
 948           lb_nat_type_t lb_nat0;
 949           twice_nat_type_t twice_nat0;
 950           u8 identity_nat0;
 951
 952           /* speculatively enqueue b0 to the current next frame */
 953           bi0 = from[0];
 954           to_next[0] = bi0;
 955           from += 1;
 956           to_next += 1;
 957           n_left_from -= 1;
 958           n_left_to_next -= 1;
 959
 960           b0 = vlib_get_buffer (vm, bi0);
 961           next0 = vnet_buffer2 (b0)->nat.arc_next;
 962
 963           vnet_buffer (b0)->snat.flags = 0;
 964           ip0 = vlib_buffer_get_current (b0);
 965
 966           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 967           rx_fib_index0 =
 968             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 969                                                  sw_if_index0);
 970
 971           if (PREDICT_FALSE (ip0->ttl == 1))
 972             {
 973               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 974               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 975                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 976                                            0);
 977               next0 = NAT_NEXT_ICMP_ERROR;
 978               goto trace0;
 979             }
 980
 981           udp0 = ip4_next_header (ip0);
 982           tcp0 = (tcp_header_t *) udp0;
 983           icmp0 = (icmp46_header_t *) udp0;
 984           proto0 = ip_proto_to_snat_proto (ip0->protocol);
 985
 986           if (PREDICT_FALSE (proto0 == ~0))
 987             {
 988               s0 =
 989                 nat44_ed_out2in_unknown_proto (sm, b0, ip0, rx_fib_index0,
 990                                                thread_index, now, vm, node);
 991               if (!sm->forwarding_enabled)
 992                 {
 993                   if (!s0)
 994                     next0 = NAT_NEXT_DROP;
 995                 }
 996               other_packets++;
 997               goto trace0;
 998             }
 999
1000           if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1001             {
1002               next0 = icmp_out2in_ed_slow_path
1003                 (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1004                  next0, now, thread_index, &s0);
1005               icmp_packets++;
1006               goto trace0;
1007             }
1008
1009           make_ed_kv (&kv0, &ip0->dst_address, &ip0->src_address,
1010                       ip0->protocol, rx_fib_index0,
1011                       vnet_buffer (b0)->ip.reass.l4_dst_port,
1012                       vnet_buffer (b0)->ip.reass.l4_src_port);
1013
1014           s0 = NULL;
1015           if (!clib_bihash_search_16_8 (&tsm->out2in_ed, &kv0, &value0))
1016             {
1017               s0 = pool_elt_at_index (tsm->sessions, value0.value);
1018
1019               if (s0->tcp_close_timestamp && now >= s0->tcp_close_timestamp)
1020                 {
1021                   nat_free_session_data (sm, s0, thread_index, 0);
1022                   nat44_ed_delete_session (sm, s0, thread_index, 1);
1023                   s0 = NULL;
1024                 }
1025             }
1026
1027           if (!s0)
1028             {
1029               /* Try to match static mapping by external address and port,
1030                  destination address and port in packet */
1031               e_key0.addr = ip0->dst_address;
1032               e_key0.port = vnet_buffer (b0)->ip.reass.l4_dst_port;
1033               e_key0.protocol = proto0;
1034               e_key0.fib_index = rx_fib_index0;
1035
1036               if (snat_static_mapping_match (sm, e_key0, &l_key0, 1, 0,
1037                                              &twice_nat0, &lb_nat0,
1038                                              &ip0->src_address,
1039                                              &identity_nat0))
1040                 {
1041                   /*
1042                    * Send DHCP packets to the ipv4 stack, or we won't
1043                    * be able to use dhcp client on the outside interface
1044                    */
1045                   if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_UDP
1046                                      && (vnet_buffer (b0)->ip.
1047                                          reass.l4_dst_port ==
1048                                          clib_host_to_net_u16
1049                                          (UDP_DST_PORT_dhcp_to_client))))
1050                     {
1051                       goto trace0;
1052                     }
1053
1054                   if (!sm->forwarding_enabled)
1055                     {
1056                       b0->error =
1057                         node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
1058                       next0 = NAT_NEXT_DROP;
1059                     }
1060                   else
1061                     {
1062                       if (next_src_nat (sm, ip0, ip0->protocol,
1063                                         vnet_buffer (b0)->ip.
1064                                         reass.l4_src_port,
1065                                         vnet_buffer (b0)->ip.
1066                                         reass.l4_dst_port, thread_index,
1067                                         rx_fib_index0))
1068                         {
1069                           next0 = NAT_NEXT_IN2OUT_ED_FAST_PATH;
1070                           goto trace0;
1071                         }
1072                       if (sm->num_workers > 1)
1073                         create_bypass_for_fwd_worker (sm, b0, ip0,
1074                                                       rx_fib_index0);
1075                       else
1076                         create_bypass_for_fwd (sm, b0, ip0, rx_fib_index0,
1077                                                thread_index);
1078                     }
1079                   goto trace0;
1080                 }
1081
1082               if (PREDICT_FALSE (identity_nat0))
1083                 goto trace0;
1084
1085               if ((proto0 == SNAT_PROTOCOL_TCP)
1086                   && !tcp_flags_is_init (vnet_buffer (b0)->ip.
1087                                          reass.icmp_type_or_tcp_flags))
1088                 {
1089                   b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
1090                   next0 = NAT_NEXT_DROP;
1091                   goto trace0;
1092                 }
1093
1094               /* Create session initiated by host from external network */
1095               s0 = create_session_for_static_mapping_ed (sm, b0, l_key0,
1096                                                          e_key0, node,
1097                                                          thread_index,
1098                                                          twice_nat0,
1099                                                          lb_nat0, now);
1100               if (!s0)
1101                 {
1102                   next0 = NAT_NEXT_DROP;
1103                   goto trace0;
1104                 }
1105             }
1106
1107           old_addr0 = ip0->dst_address.as_u32;
1108           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
1109           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
1110
1111           sum0 = ip0->checksum;
1112           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1113                                  dst_address);
1114           if (PREDICT_FALSE (is_twice_nat_session (s0)))
1115             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1116                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
1117                                    src_address);
1118           ip0->checksum = ip_csum_fold (sum0);
1119
1120           old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
1121
1122           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
1123             {
1124               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1125                 {
1126                   new_port0 = udp0->dst_port = s0->in2out.port;
1127                   sum0 = tcp0->checksum;
1128                   sum0 =
1129                     ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1130                                     dst_address);
1131                   sum0 =
1132                     ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1133                                     length);
1134                   if (is_twice_nat_session (s0))
1135                     {
1136                       sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1137                                              s0->ext_host_nat_addr.as_u32,
1138                                              ip4_header_t, dst_address);
1139                       sum0 =
1140                         ip_csum_update (sum0,
1141                                         vnet_buffer (b0)->ip.
1142                                         reass.l4_src_port,
1143                                         s0->ext_host_nat_port, ip4_header_t,
1144                                         length);
1145                       tcp0->src_port = s0->ext_host_nat_port;
1146                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1147                     }
1148                   tcp0->checksum = ip_csum_fold (sum0);
1149                 }
1150               tcp_packets++;
1151               if (nat44_set_tcp_session_state_o2i
1152                   (sm, now, s0,
1153                    vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags,
1154                    vnet_buffer (b0)->ip.reass.tcp_ack_number,
1155                    vnet_buffer (b0)->ip.reass.tcp_seq_number, thread_index))
1156                 goto trace0;
1157             }
1158           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
1159                    && udp0->checksum)
1160             {
1161               new_port0 = udp0->dst_port = s0->in2out.port;
1162               sum0 = udp0->checksum;
1163               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1164                                      dst_address);
1165               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1166                                      length);
1167               if (PREDICT_FALSE (is_twice_nat_session (s0)))
1168                 {
1169                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1170                                          s0->ext_host_nat_addr.as_u32,
1171                                          ip4_header_t, dst_address);
1172                   sum0 =
1173                     ip_csum_update (sum0,
1174                                     vnet_buffer (b0)->ip.reass.l4_src_port,
1175                                     s0->ext_host_nat_port, ip4_header_t,
1176                                     length);
1177                   udp0->src_port = s0->ext_host_nat_port;
1178                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1179                 }
1180               udp0->checksum = ip_csum_fold (sum0);
1181               udp_packets++;
1182             }
1183           else
1184             {
1185               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1186                 {
1187                   new_port0 = udp0->dst_port = s0->in2out.port;
1188                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
1189                     {
1190                       udp0->src_port = s0->ext_host_nat_port;
1191                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1192                     }
1193                 }
1194               udp_packets++;
1195             }
1196
1197           /* Accounting */
1198           nat44_session_update_counters (s0, now,
1199                                          vlib_buffer_length_in_chain (vm, b0),
1200                                          thread_index);
1201           /* Per-user LRU list maintenance */
1202           nat44_session_update_lru (sm, s0, thread_index);
1203
1204         trace0:
1205           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1206                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1207             {
1208               nat44_ed_out2in_trace_t *t =
1209                 vlib_add_trace (vm, node, b0, sizeof (*t));
1210               t->sw_if_index = sw_if_index0;
1211               t->next_index = next0;
1212               t->is_slow_path = 1;
1213
1214               if (s0)
1215                 t->session_index = s0 - tsm->sessions;
1216               else
1217                 t->session_index = ~0;
1218             }
1219
1220           pkts_processed += next0 == vnet_buffer2 (b0)->nat.arc_next;
1221           /* verify speculative enqueue, maybe switch current next frame */
1222           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1223                                            to_next, n_left_to_next,
1224                                            bi0, next0);
1225         }
1226
1227       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1228     }
1229
1230   vlib_node_increment_counter (vm, stats_node_index,
1231                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
1232                                pkts_processed);
1233   vlib_node_increment_counter (vm, stats_node_index,
1234                                NAT_OUT2IN_ED_ERROR_TCP_PACKETS, tcp_packets);
1235   vlib_node_increment_counter (vm, stats_node_index,
1236                                NAT_OUT2IN_ED_ERROR_UDP_PACKETS, udp_packets);
1237   vlib_node_increment_counter (vm, stats_node_index,
1238                                NAT_OUT2IN_ED_ERROR_ICMP_PACKETS,
1239                                icmp_packets);
1240   vlib_node_increment_counter (vm, stats_node_index,
1241                                NAT_OUT2IN_ED_ERROR_OTHER_PACKETS,
1242                                other_packets);
1243   vlib_node_increment_counter (vm, stats_node_index,
1244                                NAT_OUT2IN_ED_ERROR_FRAGMENTS, fragments);
1245   return frame->n_vectors;
1246 }
1247
1248 VLIB_NODE_FN (nat44_ed_out2in_node) (vlib_main_t * vm,
1249                                      vlib_node_runtime_t * node,
1250                                      vlib_frame_t * frame)
1251 {
1252   return nat44_ed_out2in_fast_path_node_fn_inline (vm, node, frame);
1253 }
1254
1255 /* *INDENT-OFF* */
1256 VLIB_REGISTER_NODE (nat44_ed_out2in_node) = {
1257   .name = "nat44-ed-out2in",
1258   .vector_size = sizeof (u32),
1259   .sibling_of = "nat-default",
1260   .format_trace = format_nat44_ed_out2in_trace,
1261   .type = VLIB_NODE_TYPE_INTERNAL,
1262   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1263   .error_strings = nat_out2in_ed_error_strings,
1264   .runtime_data_bytes = sizeof (snat_runtime_t),
1265 };
1266 /* *INDENT-ON* */
1267
1268 VLIB_NODE_FN (nat44_ed_out2in_slowpath_node) (vlib_main_t * vm,
1269                                               vlib_node_runtime_t * node,
1270                                               vlib_frame_t * frame)
1271 {
1272   return nat44_ed_out2in_slow_path_node_fn_inline (vm, node, frame);
1273 }
1274
1275 /* *INDENT-OFF* */
1276 VLIB_REGISTER_NODE (nat44_ed_out2in_slowpath_node) = {
1277   .name = "nat44-ed-out2in-slowpath",
1278   .vector_size = sizeof (u32),
1279   .sibling_of = "nat-default",
1280   .format_trace = format_nat44_ed_out2in_trace,
1281   .type = VLIB_NODE_TYPE_INTERNAL,
1282   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1283   .error_strings = nat_out2in_ed_error_strings,
1284   .runtime_data_bytes = sizeof (snat_runtime_t),
1285 };
1286 /* *INDENT-ON* */
1287
1288 static u8 *
1289 format_nat_pre_trace (u8 * s, va_list * args)
1290 {
1291   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1292   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1293   nat_pre_trace_t *t = va_arg (*args, nat_pre_trace_t *);
1294   return format (s, "out2in next_index %d", t->next_index);
1295 }
1296
1297 VLIB_NODE_FN (nat_pre_out2in_node) (vlib_main_t * vm,
1298                                     vlib_node_runtime_t * node,
1299                                     vlib_frame_t * frame)
1300 {
1301   return nat_pre_node_fn_inline (vm, node, frame,
1302                                  NAT_NEXT_OUT2IN_ED_FAST_PATH);
1303 }
1304
1305 /* *INDENT-OFF* */
1306 VLIB_REGISTER_NODE (nat_pre_out2in_node) = {
1307   .name = "nat-pre-out2in",
1308   .vector_size = sizeof (u32),
1309   .sibling_of = "nat-default",
1310   .format_trace = format_nat_pre_trace,
1311   .type = VLIB_NODE_TYPE_INTERNAL,
1312   .n_errors = 0,
1313  };
1314 /* *INDENT-ON* */
1315
1316 /*
1317  * fd.io coding-style-patch-verification: ON
1318  *
1319  * Local Variables:
1320  * eval: (c-set-style "gnu")
1321  * End:
1322  */