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   u8 proto;
  98   u16 r_port, l_port;
  99   ip4_address_t *l_addr, *r_addr;
 100   u32 fib_index;
 101   clib_bihash_kv_16_8_t ed_kv;
 102   int i;
 103   snat_address_t *a;
 104   snat_session_key_t key;
 105   snat_main_per_thread_data_t *tsm = vec_elt_at_index (sm->per_thread_data,
 106                                                        ctx->thread_index);
 107
 108   s = pool_elt_at_index (tsm->sessions, kv->value);
 109   sess_timeout_time = s->last_heard + (f64) nat44_session_get_timeout (sm, s);
 110   if (ctx->now >= sess_timeout_time)
 111     {
 112       l_addr = &s->in2out.addr;
 113       r_addr = &s->ext_host_addr;
 114       fib_index = s->in2out.fib_index;
 115       if (snat_is_unk_proto_session (s))
 116         {
 117           proto = s->in2out.port;
 118           r_port = 0;
 119           l_port = 0;
 120         }
 121       else
 122         {
 123           proto = snat_proto_to_ip_proto (s->in2out.protocol);
 124           l_port = s->in2out.port;
 125           r_port = s->ext_host_port;
 126         }
 127       if (is_twice_nat_session (s))
 128         {
 129           r_addr = &s->ext_host_nat_addr;
 130           r_port = s->ext_host_nat_port;
 131         }
 132       make_ed_kv (l_addr, r_addr, proto, fib_index, l_port, r_port, ~0ULL,
 133                   &ed_kv);
 134       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &ed_kv, 0))
 135         nat_elog_warn ("in2out_ed key del failed");
 136
 137       if (snat_is_unk_proto_session (s))
 138         goto delete;
 139
 140       snat_ipfix_logging_nat44_ses_delete (ctx->thread_index,
 141                                            s->in2out.addr.as_u32,
 142                                            s->out2in.addr.as_u32,
 143                                            s->in2out.protocol,
 144                                            s->in2out.port,
 145                                            s->out2in.port,
 146                                            s->in2out.fib_index);
 147
 148       nat_syslog_nat44_sdel (s->user_index, s->in2out.fib_index,
 149                              &s->in2out.addr, s->in2out.port,
 150                              &s->ext_host_nat_addr, s->ext_host_nat_port,
 151                              &s->out2in.addr, s->out2in.port,
 152                              &s->ext_host_addr, s->ext_host_port,
 153                              s->in2out.protocol, is_twice_nat_session (s));
 154
 155       nat_ha_sdel (&s->out2in.addr, s->out2in.port, &s->ext_host_addr,
 156                    s->ext_host_port, s->out2in.protocol, s->out2in.fib_index,
 157                    ctx->thread_index);
 158
 159       if (is_twice_nat_session (s))
 160         {
 161           for (i = 0; i < vec_len (sm->twice_nat_addresses); i++)
 162             {
 163               key.protocol = s->in2out.protocol;
 164               key.port = s->ext_host_nat_port;
 165               a = sm->twice_nat_addresses + i;
 166               if (a->addr.as_u32 == s->ext_host_nat_addr.as_u32)
 167                 {
 168                   snat_free_outside_address_and_port (sm->twice_nat_addresses,
 169                                                       ctx->thread_index,
 170                                                       &key);
 171                   break;
 172                 }
 173             }
 174         }
 175
 176       if (snat_is_session_static (s))
 177         goto delete;
 178
 179       snat_free_outside_address_and_port (sm->addresses, ctx->thread_index,
 180                                           &s->out2in);
 181     delete:
 182       nat44_ed_delete_session (sm, s, ctx->thread_index, 1);
 183       return 1;
 184     }
 185
 186   return 0;
 187 }
 188 #endif
 189
 190 static snat_session_t *
 191 create_session_for_static_mapping_ed (snat_main_t * sm,
 192                                       vlib_buffer_t * b,
 193                                       snat_session_key_t l_key,
 194                                       snat_session_key_t e_key,
 195                                       vlib_node_runtime_t * node,
 196                                       u32 thread_index,
 197                                       twice_nat_type_t twice_nat,
 198                                       lb_nat_type_t lb_nat, f64 now)
 199 {
 200   snat_session_t *s;
 201   ip4_header_t *ip;
 202   udp_header_t *udp;
 203   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 204   clib_bihash_kv_16_8_t kv;
 205   snat_session_key_t eh_key;
 206   nat44_is_idle_session_ctx_t ctx;
 207
 208   if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
 209     {
 210       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 211       nat_elog_notice ("maximum sessions exceeded");
 212       return 0;
 213     }
 214
 215   s = nat_ed_session_alloc (sm, thread_index, now);
 216   if (!s)
 217     {
 218       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_USER_SESS_EXCEEDED];
 219       nat_elog_warn ("create NAT session failed");
 220       return 0;
 221     }
 222
 223   ip = vlib_buffer_get_current (b);
 224   udp = ip4_next_header (ip);
 225
 226   s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 227   s->ext_host_port = e_key.protocol == SNAT_PROTOCOL_ICMP ? 0 : udp->src_port;
 228   s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 229   if (lb_nat)
 230     s->flags |= SNAT_SESSION_FLAG_LOAD_BALANCING;
 231   if (lb_nat == AFFINITY_LB_NAT)
 232     s->flags |= SNAT_SESSION_FLAG_AFFINITY;
 233   s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 234   s->out2in = e_key;
 235   s->in2out = l_key;
 236   s->in2out.protocol = s->out2in.protocol;
 237
 238   /* Add to lookup tables */
 239   make_ed_kv (&e_key.addr, &s->ext_host_addr, ip->protocol,
 240               e_key.fib_index, e_key.port, s->ext_host_port,
 241               s - tsm->sessions, &kv);
 242   ctx.now = now;
 243   ctx.thread_index = thread_index;
 244   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->out2in_ed, &kv,
 245                                                nat44_o2i_ed_is_idle_session_cb,
 246                                                &ctx))
 247     nat_elog_notice ("out2in-ed key add failed");
 248
 249   if (twice_nat == TWICE_NAT || (twice_nat == TWICE_NAT_SELF &&
 250                                  ip->src_address.as_u32 == l_key.addr.as_u32))
 251     {
 252       eh_key.protocol = e_key.protocol;
 253       if (snat_alloc_outside_address_and_port (sm->twice_nat_addresses, 0,
 254                                                thread_index, &eh_key,
 255                                                sm->port_per_thread,
 256                                                tsm->snat_thread_index))
 257         {
 258           b->error = node->errors[NAT_OUT2IN_ED_ERROR_OUT_OF_PORTS];
 259           nat44_ed_delete_session (sm, s, thread_index, 1);
 260           if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &kv, 0))
 261             nat_elog_notice ("out2in-ed key del failed");
 262           return 0;
 263         }
 264       s->ext_host_nat_addr.as_u32 = eh_key.addr.as_u32;
 265       s->ext_host_nat_port = eh_key.port;
 266       s->flags |= SNAT_SESSION_FLAG_TWICE_NAT;
 267       make_ed_kv (&l_key.addr, &s->ext_host_nat_addr, ip->protocol,
 268                   l_key.fib_index, l_key.port, s->ext_host_nat_port,
 269                   s - tsm->sessions, &kv);
 270     }
 271   else
 272     {
 273       make_ed_kv (&l_key.addr, &s->ext_host_addr, ip->protocol,
 274                   l_key.fib_index, l_key.port, s->ext_host_port,
 275                   s - tsm->sessions, &kv);
 276     }
 277   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->in2out_ed, &kv,
 278                                                nat44_i2o_ed_is_idle_session_cb,
 279                                                &ctx))
 280     nat_elog_notice ("in2out-ed key add failed");
 281
 282   snat_ipfix_logging_nat44_ses_create (thread_index,
 283                                        s->in2out.addr.as_u32,
 284                                        s->out2in.addr.as_u32,
 285                                        s->in2out.protocol,
 286                                        s->in2out.port,
 287                                        s->out2in.port, s->in2out.fib_index);
 288
 289   nat_syslog_nat44_sadd (s->user_index, s->in2out.fib_index,
 290                          &s->in2out.addr, s->in2out.port,
 291                          &s->ext_host_nat_addr, s->ext_host_nat_port,
 292                          &s->out2in.addr, s->out2in.port,
 293                          &s->ext_host_addr, s->ext_host_port,
 294                          s->in2out.protocol, is_twice_nat_session (s));
 295
 296   nat_ha_sadd (&s->in2out.addr, s->in2out.port, &s->out2in.addr,
 297                s->out2in.port, &s->ext_host_addr, s->ext_host_port,
 298                &s->ext_host_nat_addr, s->ext_host_nat_port,
 299                s->in2out.protocol, s->in2out.fib_index, s->flags,
 300                thread_index, 0);
 301
 302   return s;
 303 }
 304
 305 static int
 306 next_src_nat (snat_main_t * sm, ip4_header_t * ip, u16 src_port,
 307               u16 dst_port, u32 thread_index, u32 rx_fib_index)
 308 {
 309   clib_bihash_kv_16_8_t kv, value;
 310   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 311
 312   make_ed_kv (&ip->src_address, &ip->dst_address, ip->protocol,
 313               rx_fib_index, src_port, dst_port, ~0ULL, &kv);
 314   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 315     return 1;
 316
 317   return 0;
 318 }
 319
 320 static void
 321 create_bypass_for_fwd (snat_main_t * sm, vlib_buffer_t * b, ip4_header_t * ip,
 322                        u32 rx_fib_index, u32 thread_index)
 323 {
 324   clib_bihash_kv_16_8_t kv, value;
 325   udp_header_t *udp;
 326   snat_session_t *s = 0;
 327   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 328   f64 now = vlib_time_now (sm->vlib_main);
 329   u16 l_port, r_port;
 330
 331   if (ip->protocol == IP_PROTOCOL_ICMP)
 332     {
 333       if (get_icmp_o2i_ed_key
 334           (b, ip, rx_fib_index, ~0ULL, 0, &l_port, &r_port, &kv))
 335         return;
 336     }
 337   else
 338     {
 339       if (ip->protocol == IP_PROTOCOL_UDP || ip->protocol == IP_PROTOCOL_TCP)
 340         {
 341           udp = ip4_next_header (ip);
 342           l_port = udp->dst_port;
 343           r_port = udp->src_port;
 344         }
 345       else
 346         {
 347           l_port = 0;
 348           r_port = 0;
 349         }
 350       make_ed_kv (&ip->dst_address, &ip->src_address, ip->protocol,
 351                   rx_fib_index, l_port, r_port, ~0ULL, &kv);
 352     }
 353
 354   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 355     {
 356       s = pool_elt_at_index (tsm->sessions, value.value);
 357     }
 358   else
 359     {
 360       u32 proto;
 361
 362       if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
 363         return;
 364
 365       s = nat_ed_session_alloc (sm, thread_index, now);
 366       if (!s)
 367         {
 368           nat_elog_warn ("create NAT session failed");
 369           return;
 370         }
 371
 372       proto = ip_proto_to_snat_proto (ip->protocol);
 373
 374       s->ext_host_addr = ip->src_address;
 375       s->ext_host_port = r_port;
 376       s->flags |= SNAT_SESSION_FLAG_FWD_BYPASS;
 377       s->out2in.addr = ip->dst_address;
 378       s->out2in.port = l_port;
 379       s->out2in.protocol = proto;
 380       if (proto == ~0)
 381         {
 382           s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 383           s->out2in.port = ip->protocol;
 384         }
 385       s->out2in.fib_index = 0;
 386       s->in2out = s->out2in;
 387
 388       kv.value = s - tsm->sessions;
 389       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &kv, 1))
 390         nat_elog_notice ("in2out_ed key add failed");
 391     }
 392
 393   if (ip->protocol == IP_PROTOCOL_TCP)
 394     {
 395       tcp_header_t *tcp = ip4_next_header (ip);
 396       if (nat44_set_tcp_session_state_o2i
 397           (sm, now, s, tcp->flags, tcp->ack_number, tcp->seq_number,
 398            thread_index))
 399         return;
 400     }
 401
 402   /* Accounting */
 403   nat44_session_update_counters (s, now, 0, thread_index);
 404   /* Per-user LRU list maintenance */
 405   nat44_session_update_lru (sm, s, thread_index);
 406 }
 407
 408 static inline void
 409 create_bypass_for_fwd_worker (snat_main_t * sm, vlib_buffer_t * b,
 410                               ip4_header_t * ip, u32 rx_fib_index)
 411 {
 412   ip4_header_t ip_wkr = {
 413     .src_address = ip->dst_address,
 414   };
 415   u32 thread_index = sm->worker_in2out_cb (&ip_wkr, rx_fib_index, 0);
 416
 417   create_bypass_for_fwd (sm, b, ip, rx_fib_index, thread_index);
 418 }
 419
 420 #ifndef CLIB_MARCH_VARIANT
 421 u32
 422 icmp_match_out2in_ed (snat_main_t * sm, vlib_node_runtime_t * node,
 423                       u32 thread_index, vlib_buffer_t * b, ip4_header_t * ip,
 424                       u8 * p_proto, snat_session_key_t * p_value,
 425                       u8 * p_dont_translate, void *d, void *e)
 426 {
 427   u32 next = ~0, sw_if_index, rx_fib_index;
 428   clib_bihash_kv_16_8_t kv, value;
 429   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 430   snat_session_t *s = 0;
 431   u8 dont_translate = 0, is_addr_only, identity_nat;
 432   snat_session_key_t e_key, l_key;
 433   u16 l_port, r_port;
 434
 435   sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
 436   rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 437
 438   if (get_icmp_o2i_ed_key
 439       (b, ip, rx_fib_index, ~0ULL, p_proto, &l_port, &r_port, &kv))
 440     {
 441       b->error = node->errors[NAT_OUT2IN_ED_ERROR_UNSUPPORTED_PROTOCOL];
 442       next = NAT_NEXT_DROP;
 443       goto out;
 444     }
 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 = l_port;
 451       e_key.protocol = ip_proto_to_snat_proto (ip->protocol);
 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, l_port, 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 out:
 533   if (s)
 534     *p_value = s->in2out;
 535   *p_dont_translate = dont_translate;
 536   if (d)
 537     *(snat_session_t **) d = s;
 538   return next;
 539 }
 540 #endif
 541
 542 static snat_session_t *
 543 nat44_ed_out2in_unknown_proto (snat_main_t * sm,
 544                                vlib_buffer_t * b,
 545                                ip4_header_t * ip,
 546                                u32 rx_fib_index,
 547                                u32 thread_index,
 548                                f64 now,
 549                                vlib_main_t * vm, vlib_node_runtime_t * node)
 550 {
 551   clib_bihash_kv_8_8_t kv, value;
 552   clib_bihash_kv_16_8_t s_kv, s_value;
 553   snat_static_mapping_t *m;
 554   u32 old_addr, new_addr;
 555   ip_csum_t sum;
 556   snat_session_t *s;
 557   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 558
 559   old_addr = ip->dst_address.as_u32;
 560
 561   make_ed_kv (&ip->dst_address, &ip->src_address, ip->protocol, rx_fib_index,
 562               0, 0, ~0ULL, &s_kv);
 563
 564   if (!clib_bihash_search_16_8 (&tsm->out2in_ed, &s_kv, &s_value))
 565     {
 566       s = pool_elt_at_index (tsm->sessions, s_value.value);
 567       new_addr = ip->dst_address.as_u32 = s->in2out.addr.as_u32;
 568     }
 569   else
 570     {
 571       if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
 572         {
 573           b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 574           nat_elog_notice ("maximum sessions exceeded");
 575           return 0;
 576         }
 577
 578       make_sm_kv (&kv, &ip->dst_address, 0, 0, 0);
 579       if (clib_bihash_search_8_8
 580           (&sm->static_mapping_by_external, &kv, &value))
 581         {
 582           b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 583           return 0;
 584         }
 585
 586       m = pool_elt_at_index (sm->static_mappings, value.value);
 587
 588       new_addr = ip->dst_address.as_u32 = m->local_addr.as_u32;
 589
 590       /* Create a new session */
 591       s = nat_ed_session_alloc (sm, thread_index, now);
 592       if (!s)
 593         {
 594           b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_USER_SESS_EXCEEDED];
 595           nat_elog_warn ("create NAT session failed");
 596           return 0;
 597         }
 598
 599       s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 600       s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 601       s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 602       s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 603       s->out2in.addr.as_u32 = old_addr;
 604       s->out2in.fib_index = rx_fib_index;
 605       s->in2out.addr.as_u32 = new_addr;
 606       s->in2out.fib_index = m->fib_index;
 607       s->in2out.port = s->out2in.port = ip->protocol;
 608
 609       /* Add to lookup tables */
 610       s_kv.value = s - tsm->sessions;
 611       if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &s_kv, 1))
 612         nat_elog_notice ("out2in key add failed");
 613
 614       make_ed_kv (&ip->dst_address, &ip->src_address, ip->protocol,
 615                   m->fib_index, 0, 0, s - tsm->sessions, &s_kv);
 616       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &s_kv, 1))
 617         nat_elog_notice ("in2out key add failed");
 618     }
 619
 620   /* Update IP checksum */
 621   sum = ip->checksum;
 622   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
 623   ip->checksum = ip_csum_fold (sum);
 624
 625   vnet_buffer (b)->sw_if_index[VLIB_TX] = s->in2out.fib_index;
 626
 627   /* Accounting */
 628   nat44_session_update_counters (s, now, vlib_buffer_length_in_chain (vm, b),
 629                                  thread_index);
 630   /* Per-user LRU list maintenance */
 631   nat44_session_update_lru (sm, s, thread_index);
 632
 633   return s;
 634 }
 635
 636 static inline uword
 637 nat44_ed_out2in_fast_path_node_fn_inline (vlib_main_t * vm,
 638                                           vlib_node_runtime_t * node,
 639                                           vlib_frame_t * frame)
 640 {
 641   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
 642   nat_next_t next_index;
 643   snat_main_t *sm = &snat_main;
 644   f64 now = vlib_time_now (vm);
 645   u32 thread_index = vm->thread_index;
 646   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 647   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 648     0, fragments = 0;
 649
 650   stats_node_index = sm->ed_out2in_node_index;
 651
 652   from = vlib_frame_vector_args (frame);
 653   n_left_from = frame->n_vectors;
 654   next_index = node->cached_next_index;
 655
 656   while (n_left_from > 0)
 657     {
 658       u32 n_left_to_next;
 659
 660       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 661
 662       while (n_left_from > 0 && n_left_to_next > 0)
 663         {
 664           u32 bi0;
 665           vlib_buffer_t *b0;
 666           u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
 667             new_addr0;
 668           u16 old_port0, new_port0;
 669           ip4_header_t *ip0;
 670           udp_header_t *udp0;
 671           tcp_header_t *tcp0;
 672           snat_session_t *s0 = 0;
 673           clib_bihash_kv_16_8_t kv0, value0;
 674           ip_csum_t sum0;
 675
 676           /* speculatively enqueue b0 to the current next frame */
 677           bi0 = from[0];
 678           to_next[0] = bi0;
 679           from += 1;
 680           to_next += 1;
 681           n_left_from -= 1;
 682           n_left_to_next -= 1;
 683
 684           b0 = vlib_get_buffer (vm, bi0);
 685           next0 = vnet_buffer2 (b0)->nat.arc_next;
 686
 687           vnet_buffer (b0)->snat.flags = 0;
 688           ip0 = vlib_buffer_get_current (b0);
 689
 690           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 691           rx_fib_index0 =
 692             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 693                                                  sw_if_index0);
 694
 695           if (PREDICT_FALSE (ip0->ttl == 1))
 696             {
 697               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 698               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 699                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 700                                            0);
 701               next0 = NAT_NEXT_ICMP_ERROR;
 702               goto trace0;
 703             }
 704
 705           udp0 = ip4_next_header (ip0);
 706           tcp0 = (tcp_header_t *) udp0;
 707           proto0 = ip_proto_to_snat_proto (ip0->protocol);
 708
 709           if (PREDICT_FALSE (proto0 == ~0))
 710             {
 711               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 712               goto trace0;
 713             }
 714
 715           if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
 716             {
 717               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 718               goto trace0;
 719             }
 720
 721           make_ed_kv (&ip0->dst_address, &ip0->src_address,
 722                       ip0->protocol, rx_fib_index0,
 723                       vnet_buffer (b0)->ip.reass.l4_dst_port,
 724                       vnet_buffer (b0)->ip.reass.l4_src_port, ~0ULL, &kv0);
 725
 726           if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv0, &value0))
 727             {
 728               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 729               goto trace0;
 730             }
 731           s0 = pool_elt_at_index (tsm->sessions, value0.value);
 732
 733           if (s0->tcp_close_timestamp)
 734             {
 735               if (now >= s0->tcp_close_timestamp)
 736                 {
 737                   // session is closed, go slow path
 738                   next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 739                 }
 740               else
 741                 {
 742                   // session in transitory timeout, drop
 743                   b0->error = node->errors[NAT_OUT2IN_ED_ERROR_TCP_CLOSED];
 744                   next0 = NAT_NEXT_DROP;
 745                 }
 746               goto trace0;
 747             }
 748
 749           // drop if session expired
 750           u64 sess_timeout_time;
 751           sess_timeout_time = s0->last_heard +
 752             (f64) nat44_session_get_timeout (sm, s0);
 753           if (now >= sess_timeout_time)
 754             {
 755               // session is closed, go slow path
 756               nat_free_session_data (sm, s0, thread_index, 0);
 757               nat44_ed_delete_session (sm, s0, thread_index, 1);
 758               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 759               goto trace0;
 760             }
 761           //
 762
 763           old_addr0 = ip0->dst_address.as_u32;
 764           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
 765           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
 766
 767           sum0 = ip0->checksum;
 768           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 769                                  dst_address);
 770           if (PREDICT_FALSE (is_twice_nat_session (s0)))
 771             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 772                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
 773                                    src_address);
 774           ip0->checksum = ip_csum_fold (sum0);
 775
 776           old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
 777
 778           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
 779             {
 780               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 781                 {
 782                   new_port0 = udp0->dst_port = s0->in2out.port;
 783                   sum0 = tcp0->checksum;
 784                   sum0 =
 785                     ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 786                                     dst_address);
 787                   sum0 =
 788                     ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 789                                     length);
 790                   if (is_twice_nat_session (s0))
 791                     {
 792                       sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 793                                              s0->ext_host_nat_addr.as_u32,
 794                                              ip4_header_t, dst_address);
 795                       sum0 =
 796                         ip_csum_update (sum0,
 797                                         vnet_buffer (b0)->ip.
 798                                         reass.l4_src_port,
 799                                         s0->ext_host_nat_port, ip4_header_t,
 800                                         length);
 801                       tcp0->src_port = s0->ext_host_nat_port;
 802                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 803                     }
 804                   tcp0->checksum = ip_csum_fold (sum0);
 805                 }
 806               tcp_packets++;
 807               if (nat44_set_tcp_session_state_o2i
 808                   (sm, now, s0,
 809                    vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags,
 810                    vnet_buffer (b0)->ip.reass.tcp_ack_number,
 811                    vnet_buffer (b0)->ip.reass.tcp_seq_number, thread_index))
 812                 goto trace0;
 813             }
 814           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
 815                    && udp0->checksum)
 816             {
 817               new_port0 = udp0->dst_port = s0->in2out.port;
 818               sum0 = udp0->checksum;
 819               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 820                                      dst_address);
 821               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 822                                      length);
 823               if (PREDICT_FALSE (is_twice_nat_session (s0)))
 824                 {
 825                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 826                                          s0->ext_host_nat_addr.as_u32,
 827                                          ip4_header_t, dst_address);
 828                   sum0 =
 829                     ip_csum_update (sum0,
 830                                     vnet_buffer (b0)->ip.reass.l4_src_port,
 831                                     s0->ext_host_nat_port, ip4_header_t,
 832                                     length);
 833                   udp0->src_port = s0->ext_host_nat_port;
 834                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 835                 }
 836               udp0->checksum = ip_csum_fold (sum0);
 837               udp_packets++;
 838             }
 839           else
 840             {
 841               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 842                 {
 843                   new_port0 = udp0->dst_port = s0->in2out.port;
 844                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
 845                     {
 846                       udp0->src_port = s0->ext_host_nat_port;
 847                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 848                     }
 849                 }
 850               udp_packets++;
 851             }
 852
 853           /* Accounting */
 854           nat44_session_update_counters (s0, now,
 855                                          vlib_buffer_length_in_chain (vm, b0),
 856                                          thread_index);
 857           /* Per-user LRU list maintenance */
 858           nat44_session_update_lru (sm, s0, thread_index);
 859
 860         trace0:
 861           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 862                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 863             {
 864               nat44_ed_out2in_trace_t *t =
 865                 vlib_add_trace (vm, node, b0, sizeof (*t));
 866               t->sw_if_index = sw_if_index0;
 867               t->next_index = next0;
 868               t->is_slow_path = 0;
 869
 870               if (s0)
 871                 t->session_index = s0 - tsm->sessions;
 872               else
 873                 t->session_index = ~0;
 874             }
 875
 876           pkts_processed += next0 == vnet_buffer2 (b0)->nat.arc_next;
 877           /* verify speculative enqueue, maybe switch current next frame */
 878           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 879                                            to_next, n_left_to_next,
 880                                            bi0, next0);
 881         }
 882
 883       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 884     }
 885
 886   vlib_node_increment_counter (vm, stats_node_index,
 887                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
 888                                pkts_processed);
 889   vlib_node_increment_counter (vm, stats_node_index,
 890                                NAT_OUT2IN_ED_ERROR_TCP_PACKETS, tcp_packets);
 891   vlib_node_increment_counter (vm, stats_node_index,
 892                                NAT_OUT2IN_ED_ERROR_UDP_PACKETS, udp_packets);
 893   vlib_node_increment_counter (vm, stats_node_index,
 894                                NAT_OUT2IN_ED_ERROR_ICMP_PACKETS,
 895                                icmp_packets);
 896   vlib_node_increment_counter (vm, stats_node_index,
 897                                NAT_OUT2IN_ED_ERROR_OTHER_PACKETS,
 898                                other_packets);
 899   vlib_node_increment_counter (vm, stats_node_index,
 900                                NAT_OUT2IN_ED_ERROR_FRAGMENTS, fragments);
 901   return frame->n_vectors;
 902 }
 903
 904 static inline uword
 905 nat44_ed_out2in_slow_path_node_fn_inline (vlib_main_t * vm,
 906                                           vlib_node_runtime_t * node,
 907                                           vlib_frame_t * frame)
 908 {
 909   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
 910   nat_next_t next_index;
 911   snat_main_t *sm = &snat_main;
 912   f64 now = vlib_time_now (vm);
 913   u32 thread_index = vm->thread_index;
 914   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 915   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 916     0, fragments = 0;
 917
 918   stats_node_index = sm->ed_out2in_slowpath_node_index;
 919
 920   from = vlib_frame_vector_args (frame);
 921   n_left_from = frame->n_vectors;
 922   next_index = node->cached_next_index;
 923
 924   while (n_left_from > 0)
 925     {
 926       u32 n_left_to_next;
 927
 928       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 929
 930       while (n_left_from > 0 && n_left_to_next > 0)
 931         {
 932           u32 bi0;
 933           vlib_buffer_t *b0;
 934           u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
 935             new_addr0;
 936           u16 old_port0, new_port0;
 937           ip4_header_t *ip0;
 938           udp_header_t *udp0;
 939           tcp_header_t *tcp0;
 940           icmp46_header_t *icmp0;
 941           snat_session_t *s0 = 0;
 942           clib_bihash_kv_16_8_t kv0, value0;
 943           ip_csum_t sum0;
 944           snat_session_key_t e_key0, l_key0;
 945           lb_nat_type_t lb_nat0;
 946           twice_nat_type_t twice_nat0;
 947           u8 identity_nat0;
 948
 949           /* speculatively enqueue b0 to the current next frame */
 950           bi0 = from[0];
 951           to_next[0] = bi0;
 952           from += 1;
 953           to_next += 1;
 954           n_left_from -= 1;
 955           n_left_to_next -= 1;
 956
 957           b0 = vlib_get_buffer (vm, bi0);
 958           next0 = vnet_buffer2 (b0)->nat.arc_next;
 959
 960           vnet_buffer (b0)->snat.flags = 0;
 961           ip0 = vlib_buffer_get_current (b0);
 962
 963           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 964           rx_fib_index0 =
 965             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 966                                                  sw_if_index0);
 967
 968           if (PREDICT_FALSE (ip0->ttl == 1))
 969             {
 970               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 971               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 972                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 973                                            0);
 974               next0 = NAT_NEXT_ICMP_ERROR;
 975               goto trace0;
 976             }
 977
 978           udp0 = ip4_next_header (ip0);
 979           tcp0 = (tcp_header_t *) udp0;
 980           icmp0 = (icmp46_header_t *) udp0;
 981           proto0 = ip_proto_to_snat_proto (ip0->protocol);
 982
 983           if (PREDICT_FALSE (proto0 == ~0))
 984             {
 985               s0 =
 986                 nat44_ed_out2in_unknown_proto (sm, b0, ip0, rx_fib_index0,
 987                                                thread_index, now, vm, node);
 988               if (!sm->forwarding_enabled)
 989                 {
 990                   if (!s0)
 991                     next0 = NAT_NEXT_DROP;
 992                 }
 993               other_packets++;
 994               goto trace0;
 995             }
 996
 997           if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
 998             {
 999               next0 = icmp_out2in_ed_slow_path
1000                 (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1001                  next0, now, thread_index, &s0);
1002               icmp_packets++;
1003               goto trace0;
1004             }
1005
1006           make_ed_kv (&ip0->dst_address, &ip0->src_address,
1007                       ip0->protocol, rx_fib_index0,
1008                       vnet_buffer (b0)->ip.reass.l4_dst_port,
1009                       vnet_buffer (b0)->ip.reass.l4_src_port, ~0ULL, &kv0);
1010
1011           s0 = NULL;
1012           if (!clib_bihash_search_16_8 (&tsm->out2in_ed, &kv0, &value0))
1013             {
1014               s0 = pool_elt_at_index (tsm->sessions, value0.value);
1015
1016               if (s0->tcp_close_timestamp && now >= s0->tcp_close_timestamp)
1017                 {
1018                   nat_free_session_data (sm, s0, thread_index, 0);
1019                   nat44_ed_delete_session (sm, s0, thread_index, 1);
1020                   s0 = NULL;
1021                 }
1022             }
1023
1024           if (!s0)
1025             {
1026               /* Try to match static mapping by external address and port,
1027                  destination address and port in packet */
1028               e_key0.addr = ip0->dst_address;
1029               e_key0.port = vnet_buffer (b0)->ip.reass.l4_dst_port;
1030               e_key0.protocol = proto0;
1031               e_key0.fib_index = rx_fib_index0;
1032
1033               if (snat_static_mapping_match (sm, e_key0, &l_key0, 1, 0,
1034                                              &twice_nat0, &lb_nat0,
1035                                              &ip0->src_address,
1036                                              &identity_nat0))
1037                 {
1038                   /*
1039                    * Send DHCP packets to the ipv4 stack, or we won't
1040                    * be able to use dhcp client on the outside interface
1041                    */
1042                   if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_UDP
1043                                      && (vnet_buffer (b0)->ip.
1044                                          reass.l4_dst_port ==
1045                                          clib_host_to_net_u16
1046                                          (UDP_DST_PORT_dhcp_to_client))))
1047                     {
1048                       goto trace0;
1049                     }
1050
1051                   if (!sm->forwarding_enabled)
1052                     {
1053                       b0->error =
1054                         node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
1055                       next0 = NAT_NEXT_DROP;
1056                     }
1057                   else
1058                     {
1059                       if (next_src_nat
1060                           (sm, ip0, vnet_buffer (b0)->ip.reass.l4_src_port,
1061                            vnet_buffer (b0)->ip.reass.l4_dst_port,
1062                            thread_index, rx_fib_index0))
1063                         {
1064                           next0 = NAT_NEXT_IN2OUT_ED_FAST_PATH;
1065                           goto trace0;
1066                         }
1067                       if (sm->num_workers > 1)
1068                         create_bypass_for_fwd_worker (sm, b0, ip0,
1069                                                       rx_fib_index0);
1070                       else
1071                         create_bypass_for_fwd (sm, b0, ip0, rx_fib_index0,
1072                                                thread_index);
1073                     }
1074                   goto trace0;
1075                 }
1076
1077               if (PREDICT_FALSE (identity_nat0))
1078                 goto trace0;
1079
1080               if ((proto0 == SNAT_PROTOCOL_TCP)
1081                   && !tcp_flags_is_init (vnet_buffer (b0)->ip.
1082                                          reass.icmp_type_or_tcp_flags))
1083                 {
1084                   b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
1085                   next0 = NAT_NEXT_DROP;
1086                   goto trace0;
1087                 }
1088
1089               /* Create session initiated by host from external network */
1090               s0 = create_session_for_static_mapping_ed (sm, b0, l_key0,
1091                                                          e_key0, node,
1092                                                          thread_index,
1093                                                          twice_nat0,
1094                                                          lb_nat0, now);
1095               if (!s0)
1096                 {
1097                   next0 = NAT_NEXT_DROP;
1098                   goto trace0;
1099                 }
1100             }
1101
1102           old_addr0 = ip0->dst_address.as_u32;
1103           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
1104           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
1105
1106           sum0 = ip0->checksum;
1107           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1108                                  dst_address);
1109           if (PREDICT_FALSE (is_twice_nat_session (s0)))
1110             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1111                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
1112                                    src_address);
1113           ip0->checksum = ip_csum_fold (sum0);
1114
1115           old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
1116
1117           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
1118             {
1119               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1120                 {
1121                   new_port0 = udp0->dst_port = s0->in2out.port;
1122                   sum0 = tcp0->checksum;
1123                   sum0 =
1124                     ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1125                                     dst_address);
1126                   sum0 =
1127                     ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1128                                     length);
1129                   if (is_twice_nat_session (s0))
1130                     {
1131                       sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1132                                              s0->ext_host_nat_addr.as_u32,
1133                                              ip4_header_t, dst_address);
1134                       sum0 =
1135                         ip_csum_update (sum0,
1136                                         vnet_buffer (b0)->ip.
1137                                         reass.l4_src_port,
1138                                         s0->ext_host_nat_port, ip4_header_t,
1139                                         length);
1140                       tcp0->src_port = s0->ext_host_nat_port;
1141                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1142                     }
1143                   tcp0->checksum = ip_csum_fold (sum0);
1144                 }
1145               tcp_packets++;
1146               if (nat44_set_tcp_session_state_o2i
1147                   (sm, now, s0,
1148                    vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags,
1149                    vnet_buffer (b0)->ip.reass.tcp_ack_number,
1150                    vnet_buffer (b0)->ip.reass.tcp_seq_number, thread_index))
1151                 goto trace0;
1152             }
1153           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
1154                    && udp0->checksum)
1155             {
1156               new_port0 = udp0->dst_port = s0->in2out.port;
1157               sum0 = udp0->checksum;
1158               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1159                                      dst_address);
1160               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1161                                      length);
1162               if (PREDICT_FALSE (is_twice_nat_session (s0)))
1163                 {
1164                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1165                                          s0->ext_host_nat_addr.as_u32,
1166                                          ip4_header_t, dst_address);
1167                   sum0 =
1168                     ip_csum_update (sum0,
1169                                     vnet_buffer (b0)->ip.reass.l4_src_port,
1170                                     s0->ext_host_nat_port, ip4_header_t,
1171                                     length);
1172                   udp0->src_port = s0->ext_host_nat_port;
1173                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1174                 }
1175               udp0->checksum = ip_csum_fold (sum0);
1176               udp_packets++;
1177             }
1178           else
1179             {
1180               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1181                 {
1182                   new_port0 = udp0->dst_port = s0->in2out.port;
1183                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
1184                     {
1185                       udp0->src_port = s0->ext_host_nat_port;
1186                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1187                     }
1188                 }
1189               udp_packets++;
1190             }
1191
1192           /* Accounting */
1193           nat44_session_update_counters (s0, now,
1194                                          vlib_buffer_length_in_chain (vm, b0),
1195                                          thread_index);
1196           /* Per-user LRU list maintenance */
1197           nat44_session_update_lru (sm, s0, thread_index);
1198
1199         trace0:
1200           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1201                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1202             {
1203               nat44_ed_out2in_trace_t *t =
1204                 vlib_add_trace (vm, node, b0, sizeof (*t));
1205               t->sw_if_index = sw_if_index0;
1206               t->next_index = next0;
1207               t->is_slow_path = 1;
1208
1209               if (s0)
1210                 t->session_index = s0 - tsm->sessions;
1211               else
1212                 t->session_index = ~0;
1213             }
1214
1215           pkts_processed += next0 == vnet_buffer2 (b0)->nat.arc_next;
1216           /* verify speculative enqueue, maybe switch current next frame */
1217           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1218                                            to_next, n_left_to_next,
1219                                            bi0, next0);
1220         }
1221
1222       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1223     }
1224
1225   vlib_node_increment_counter (vm, stats_node_index,
1226                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
1227                                pkts_processed);
1228   vlib_node_increment_counter (vm, stats_node_index,
1229                                NAT_OUT2IN_ED_ERROR_TCP_PACKETS, tcp_packets);
1230   vlib_node_increment_counter (vm, stats_node_index,
1231                                NAT_OUT2IN_ED_ERROR_UDP_PACKETS, udp_packets);
1232   vlib_node_increment_counter (vm, stats_node_index,
1233                                NAT_OUT2IN_ED_ERROR_ICMP_PACKETS,
1234                                icmp_packets);
1235   vlib_node_increment_counter (vm, stats_node_index,
1236                                NAT_OUT2IN_ED_ERROR_OTHER_PACKETS,
1237                                other_packets);
1238   vlib_node_increment_counter (vm, stats_node_index,
1239                                NAT_OUT2IN_ED_ERROR_FRAGMENTS, fragments);
1240   return frame->n_vectors;
1241 }
1242
1243 VLIB_NODE_FN (nat44_ed_out2in_node) (vlib_main_t * vm,
1244                                      vlib_node_runtime_t * node,
1245                                      vlib_frame_t * frame)
1246 {
1247   return nat44_ed_out2in_fast_path_node_fn_inline (vm, node, frame);
1248 }
1249
1250 /* *INDENT-OFF* */
1251 VLIB_REGISTER_NODE (nat44_ed_out2in_node) = {
1252   .name = "nat44-ed-out2in",
1253   .vector_size = sizeof (u32),
1254   .sibling_of = "nat-default",
1255   .format_trace = format_nat44_ed_out2in_trace,
1256   .type = VLIB_NODE_TYPE_INTERNAL,
1257   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1258   .error_strings = nat_out2in_ed_error_strings,
1259   .runtime_data_bytes = sizeof (snat_runtime_t),
1260 };
1261 /* *INDENT-ON* */
1262
1263 VLIB_NODE_FN (nat44_ed_out2in_slowpath_node) (vlib_main_t * vm,
1264                                               vlib_node_runtime_t * node,
1265                                               vlib_frame_t * frame)
1266 {
1267   return nat44_ed_out2in_slow_path_node_fn_inline (vm, node, frame);
1268 }
1269
1270 /* *INDENT-OFF* */
1271 VLIB_REGISTER_NODE (nat44_ed_out2in_slowpath_node) = {
1272   .name = "nat44-ed-out2in-slowpath",
1273   .vector_size = sizeof (u32),
1274   .sibling_of = "nat-default",
1275   .format_trace = format_nat44_ed_out2in_trace,
1276   .type = VLIB_NODE_TYPE_INTERNAL,
1277   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1278   .error_strings = nat_out2in_ed_error_strings,
1279   .runtime_data_bytes = sizeof (snat_runtime_t),
1280 };
1281 /* *INDENT-ON* */
1282
1283 static u8 *
1284 format_nat_pre_trace (u8 * s, va_list * args)
1285 {
1286   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1287   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1288   nat_pre_trace_t *t = va_arg (*args, nat_pre_trace_t *);
1289   return format (s, "out2in next_index %d", t->next_index);
1290 }
1291
1292 VLIB_NODE_FN (nat_pre_out2in_node) (vlib_main_t * vm,
1293                                     vlib_node_runtime_t * node,
1294                                     vlib_frame_t * frame)
1295 {
1296   return nat_pre_node_fn_inline (vm, node, frame,
1297                                  NAT_NEXT_OUT2IN_ED_FAST_PATH);
1298 }
1299
1300 /* *INDENT-OFF* */
1301 VLIB_REGISTER_NODE (nat_pre_out2in_node) = {
1302   .name = "nat-pre-out2in",
1303   .vector_size = sizeof (u32),
1304   .sibling_of = "nat-default",
1305   .format_trace = format_nat_pre_trace,
1306   .type = VLIB_NODE_TYPE_INTERNAL,
1307   .n_errors = 0,
1308  };
1309 /* *INDENT-ON* */
1310
1311 /*
1312  * fd.io coding-style-patch-verification: ON
1313  *
1314  * Local Variables:
1315  * eval: (c-set-style "gnu")
1316  * End:
1317  */