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_delete_session (sm, s, ctx->thread_index);
 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   snat_user_t *u;
 199   ip4_header_t *ip;
 200   udp_header_t *udp;
 201   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 202   clib_bihash_kv_16_8_t kv;
 203   snat_session_key_t eh_key;
 204   nat44_is_idle_session_ctx_t ctx;
 205
 206   if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
 207     {
 208       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 209       nat_elog_notice ("maximum sessions exceeded");
 210       return 0;
 211     }
 212
 213   u = nat_user_get_or_create (sm, &l_key.addr, l_key.fib_index, thread_index);
 214   if (!u)
 215     {
 216       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 217       nat_elog_warn ("create NAT user failed");
 218       return 0;
 219     }
 220
 221   s = nat_ed_session_alloc (sm, u, thread_index, now);
 222   if (!s)
 223     {
 224       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_USER_SESS_EXCEEDED];
 225       nat44_delete_user_with_no_session (sm, u, thread_index);
 226       nat_elog_warn ("create NAT session failed");
 227       return 0;
 228     }
 229
 230   ip = vlib_buffer_get_current (b);
 231   udp = ip4_next_header (ip);
 232
 233   s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 234   s->ext_host_port = e_key.protocol == SNAT_PROTOCOL_ICMP ? 0 : udp->src_port;
 235   s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 236   if (lb_nat)
 237     s->flags |= SNAT_SESSION_FLAG_LOAD_BALANCING;
 238   if (lb_nat == AFFINITY_LB_NAT)
 239     s->flags |= SNAT_SESSION_FLAG_AFFINITY;
 240   s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 241   s->out2in = e_key;
 242   s->in2out = l_key;
 243   s->in2out.protocol = s->out2in.protocol;
 244   user_session_increment (sm, u, 1);
 245
 246   /* Add to lookup tables */
 247   make_ed_kv (&kv, &e_key.addr, &s->ext_host_addr, ip->protocol,
 248               e_key.fib_index, e_key.port, s->ext_host_port);
 249   kv.value = s - tsm->sessions;
 250   ctx.now = now;
 251   ctx.thread_index = thread_index;
 252   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->out2in_ed, &kv,
 253                                                nat44_o2i_ed_is_idle_session_cb,
 254                                                &ctx))
 255     nat_elog_notice ("out2in-ed key add failed");
 256
 257   if (twice_nat == TWICE_NAT || (twice_nat == TWICE_NAT_SELF &&
 258                                  ip->src_address.as_u32 == l_key.addr.as_u32))
 259     {
 260       eh_key.protocol = e_key.protocol;
 261       if (snat_alloc_outside_address_and_port (sm->twice_nat_addresses, 0,
 262                                                thread_index, &eh_key,
 263                                                sm->port_per_thread,
 264                                                tsm->snat_thread_index))
 265         {
 266           b->error = node->errors[NAT_OUT2IN_ED_ERROR_OUT_OF_PORTS];
 267           nat44_delete_session (sm, s, thread_index);
 268           if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &kv, 0))
 269             nat_elog_notice ("out2in-ed key del failed");
 270           return 0;
 271         }
 272       s->ext_host_nat_addr.as_u32 = eh_key.addr.as_u32;
 273       s->ext_host_nat_port = eh_key.port;
 274       s->flags |= SNAT_SESSION_FLAG_TWICE_NAT;
 275       make_ed_kv (&kv, &l_key.addr, &s->ext_host_nat_addr, ip->protocol,
 276                   l_key.fib_index, l_key.port, s->ext_host_nat_port);
 277     }
 278   else
 279     {
 280       make_ed_kv (&kv, &l_key.addr, &s->ext_host_addr, ip->protocol,
 281                   l_key.fib_index, l_key.port, s->ext_host_port);
 282     }
 283   kv.value = s - tsm->sessions;
 284   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->in2out_ed, &kv,
 285                                                nat44_i2o_ed_is_idle_session_cb,
 286                                                &ctx))
 287     nat_elog_notice ("in2out-ed key add failed");
 288
 289   snat_ipfix_logging_nat44_ses_create (thread_index,
 290                                        s->in2out.addr.as_u32,
 291                                        s->out2in.addr.as_u32,
 292                                        s->in2out.protocol,
 293                                        s->in2out.port,
 294                                        s->out2in.port, s->in2out.fib_index);
 295
 296   nat_syslog_nat44_sadd (s->user_index, s->in2out.fib_index,
 297                          &s->in2out.addr, s->in2out.port,
 298                          &s->ext_host_nat_addr, s->ext_host_nat_port,
 299                          &s->out2in.addr, s->out2in.port,
 300                          &s->ext_host_addr, s->ext_host_port,
 301                          s->in2out.protocol, is_twice_nat_session (s));
 302
 303   nat_ha_sadd (&s->in2out.addr, s->in2out.port, &s->out2in.addr,
 304                s->out2in.port, &s->ext_host_addr, s->ext_host_port,
 305                &s->ext_host_nat_addr, s->ext_host_nat_port,
 306                s->in2out.protocol, s->in2out.fib_index, s->flags,
 307                thread_index, 0);
 308
 309   return s;
 310 }
 311
 312 static int
 313 next_src_nat (snat_main_t * sm, ip4_header_t * ip, u8 proto, u16 src_port,
 314               u16 dst_port, u32 thread_index, u32 rx_fib_index)
 315 {
 316   clib_bihash_kv_16_8_t kv, value;
 317   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 318
 319   make_ed_kv (&kv, &ip->src_address, &ip->dst_address, proto,
 320               rx_fib_index, src_port, dst_port);
 321   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 322     return 1;
 323
 324   return 0;
 325 }
 326
 327 static void
 328 create_bypass_for_fwd (snat_main_t * sm, vlib_buffer_t * b, ip4_header_t * ip,
 329                        u32 rx_fib_index, u32 thread_index)
 330 {
 331   nat_ed_ses_key_t key;
 332   clib_bihash_kv_16_8_t kv, value;
 333   udp_header_t *udp;
 334   snat_user_t *u;
 335   snat_session_t *s = 0;
 336   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 337   f64 now = vlib_time_now (sm->vlib_main);
 338
 339   if (ip->protocol == IP_PROTOCOL_ICMP)
 340     {
 341       if (get_icmp_o2i_ed_key (b, ip, &key))
 342         return;
 343     }
 344   else if (ip->protocol == IP_PROTOCOL_UDP || ip->protocol == IP_PROTOCOL_TCP)
 345     {
 346       udp = ip4_next_header (ip);
 347       key.r_addr = ip->src_address;
 348       key.l_addr = ip->dst_address;
 349       key.proto = ip->protocol;
 350       key.l_port = udp->dst_port;
 351       key.r_port = udp->src_port;
 352     }
 353   else
 354     {
 355       key.r_addr = ip->src_address;
 356       key.l_addr = ip->dst_address;
 357       key.proto = ip->protocol;
 358       key.l_port = key.r_port = 0;
 359     }
 360   key.fib_index = 0;
 361   kv.key[0] = key.as_u64[0];
 362   kv.key[1] = key.as_u64[1];
 363
 364   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 365     {
 366       s = pool_elt_at_index (tsm->sessions, value.value);
 367     }
 368   else
 369     {
 370       u32 proto;
 371
 372       if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
 373         return;
 374
 375       u = nat_user_get_or_create (sm, &ip->dst_address, sm->inside_fib_index,
 376                                   thread_index);
 377       if (!u)
 378         {
 379           nat_elog_warn ("create NAT user failed");
 380           return;
 381         }
 382
 383       s = nat_ed_session_alloc (sm, u, thread_index, now);
 384       if (!s)
 385         {
 386           nat44_delete_user_with_no_session (sm, u, thread_index);
 387           nat_elog_warn ("create NAT session failed");
 388           return;
 389         }
 390
 391       proto = ip_proto_to_snat_proto (key.proto);
 392
 393       s->ext_host_addr = key.r_addr;
 394       s->ext_host_port = key.r_port;
 395       s->flags |= SNAT_SESSION_FLAG_FWD_BYPASS;
 396       s->out2in.addr = key.l_addr;
 397       s->out2in.port = key.l_port;
 398       s->out2in.protocol = proto;
 399       if (proto == ~0)
 400         {
 401           s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 402           s->out2in.port = ip->protocol;
 403         }
 404       s->out2in.fib_index = 0;
 405       s->in2out = s->out2in;
 406       user_session_increment (sm, u, 0);
 407
 408       kv.value = s - tsm->sessions;
 409       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &kv, 1))
 410         nat_elog_notice ("in2out_ed key add failed");
 411     }
 412
 413   if (ip->protocol == IP_PROTOCOL_TCP)
 414     {
 415       tcp_header_t *tcp = ip4_next_header (ip);
 416       if (nat44_set_tcp_session_state_o2i
 417           (sm, now, s, tcp->flags, tcp->ack_number, tcp->seq_number,
 418            thread_index))
 419         return;
 420     }
 421
 422   /* Accounting */
 423   nat44_session_update_counters (s, now, 0, thread_index);
 424   /* Per-user LRU list maintenance */
 425   nat44_session_update_lru (sm, s, thread_index);
 426 }
 427
 428 static inline void
 429 create_bypass_for_fwd_worker (snat_main_t * sm, vlib_buffer_t * b,
 430                               ip4_header_t * ip, u32 rx_fib_index)
 431 {
 432   ip4_header_t ip_wkr = {
 433     .src_address = ip->dst_address,
 434   };
 435   u32 thread_index = sm->worker_in2out_cb (&ip_wkr, rx_fib_index, 0);
 436
 437   create_bypass_for_fwd (sm, b, ip, rx_fib_index, thread_index);
 438 }
 439
 440 #ifndef CLIB_MARCH_VARIANT
 441 u32
 442 icmp_match_out2in_ed (snat_main_t * sm, vlib_node_runtime_t * node,
 443                       u32 thread_index, vlib_buffer_t * b, ip4_header_t * ip,
 444                       u8 * p_proto, snat_session_key_t * p_value,
 445                       u8 * p_dont_translate, void *d, void *e)
 446 {
 447   u32 next = ~0, sw_if_index, rx_fib_index;
 448   nat_ed_ses_key_t key;
 449   clib_bihash_kv_16_8_t kv, value;
 450   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 451   snat_session_t *s = 0;
 452   u8 dont_translate = 0, is_addr_only, identity_nat;
 453   snat_session_key_t e_key, l_key;
 454
 455   sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
 456   rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 457
 458   if (get_icmp_o2i_ed_key (b, ip, &key))
 459     {
 460       b->error = node->errors[NAT_OUT2IN_ED_ERROR_UNSUPPORTED_PROTOCOL];
 461       next = NAT_NEXT_DROP;
 462       goto out;
 463     }
 464   key.fib_index = rx_fib_index;
 465   kv.key[0] = key.as_u64[0];
 466   kv.key[1] = key.as_u64[1];
 467
 468   if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv, &value))
 469     {
 470       /* Try to match static mapping */
 471       e_key.addr = ip->dst_address;
 472       e_key.port = key.l_port;
 473       e_key.protocol = ip_proto_to_snat_proto (key.proto);
 474       e_key.fib_index = rx_fib_index;
 475       if (snat_static_mapping_match
 476           (sm, e_key, &l_key, 1, &is_addr_only, 0, 0, 0, &identity_nat))
 477         {
 478           if (!sm->forwarding_enabled)
 479             {
 480               /* Don't NAT packet aimed at the intfc address */
 481               if (PREDICT_FALSE (is_interface_addr (sm, node, sw_if_index,
 482                                                     ip->dst_address.as_u32)))
 483                 {
 484                   dont_translate = 1;
 485                   goto out;
 486                 }
 487               b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 488               next = NAT_NEXT_DROP;
 489               goto out;
 490             }
 491           else
 492             {
 493               dont_translate = 1;
 494               if (next_src_nat (sm, ip, key.proto, key.l_port, key.r_port,
 495                                 thread_index, rx_fib_index))
 496                 {
 497                   next = NAT_NEXT_IN2OUT_ED_FAST_PATH;
 498                   goto out;
 499                 }
 500               if (sm->num_workers > 1)
 501                 create_bypass_for_fwd_worker (sm, b, ip, rx_fib_index);
 502               else
 503                 create_bypass_for_fwd (sm, b, ip, rx_fib_index, thread_index);
 504               goto out;
 505             }
 506         }
 507
 508       if (PREDICT_FALSE
 509           (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 510            ICMP4_echo_reply
 511            && (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 512                ICMP4_echo_request || !is_addr_only)))
 513         {
 514           b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 515           next = NAT_NEXT_DROP;
 516           goto out;
 517         }
 518
 519       if (PREDICT_FALSE (identity_nat))
 520         {
 521           dont_translate = 1;
 522           goto out;
 523         }
 524
 525       /* Create session initiated by host from external network */
 526       s = create_session_for_static_mapping_ed (sm, b, l_key, e_key, node,
 527                                                 thread_index, 0, 0,
 528                                                 vlib_time_now
 529                                                 (sm->vlib_main));
 530
 531       if (!s)
 532         {
 533           next = NAT_NEXT_DROP;
 534           goto out;
 535         }
 536     }
 537   else
 538     {
 539       if (PREDICT_FALSE
 540           (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 541            ICMP4_echo_reply
 542            && vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
 543            ICMP4_echo_request
 544            && !icmp_type_is_error_message (vnet_buffer (b)->ip.
 545                                            reass.icmp_type_or_tcp_flags)))
 546         {
 547           b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 548           next = NAT_NEXT_DROP;
 549           goto out;
 550         }
 551
 552       s = pool_elt_at_index (tsm->sessions, value.value);
 553     }
 554
 555   *p_proto = ip_proto_to_snat_proto (key.proto);
 556 out:
 557   if (s)
 558     *p_value = s->in2out;
 559   *p_dont_translate = dont_translate;
 560   if (d)
 561     *(snat_session_t **) d = s;
 562   return next;
 563 }
 564 #endif
 565
 566 static snat_session_t *
 567 nat44_ed_out2in_unknown_proto (snat_main_t * sm,
 568                                vlib_buffer_t * b,
 569                                ip4_header_t * ip,
 570                                u32 rx_fib_index,
 571                                u32 thread_index,
 572                                f64 now,
 573                                vlib_main_t * vm, vlib_node_runtime_t * node)
 574 {
 575   clib_bihash_kv_8_8_t kv, value;
 576   clib_bihash_kv_16_8_t s_kv, s_value;
 577   snat_static_mapping_t *m;
 578   u32 old_addr, new_addr;
 579   ip_csum_t sum;
 580   snat_session_t *s;
 581   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 582   snat_user_t *u;
 583
 584   old_addr = ip->dst_address.as_u32;
 585
 586   make_ed_kv (&s_kv, &ip->dst_address, &ip->src_address, ip->protocol,
 587               rx_fib_index, 0, 0);
 588
 589   if (!clib_bihash_search_16_8 (&tsm->out2in_ed, &s_kv, &s_value))
 590     {
 591       s = pool_elt_at_index (tsm->sessions, s_value.value);
 592       new_addr = ip->dst_address.as_u32 = s->in2out.addr.as_u32;
 593     }
 594   else
 595     {
 596       if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
 597         {
 598           b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 599           nat_elog_notice ("maximum sessions exceeded");
 600           return 0;
 601         }
 602
 603       make_sm_kv (&kv, &ip->dst_address, 0, 0, 0);
 604       if (clib_bihash_search_8_8
 605           (&sm->static_mapping_by_external, &kv, &value))
 606         {
 607           b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 608           return 0;
 609         }
 610
 611       m = pool_elt_at_index (sm->static_mappings, value.value);
 612
 613       new_addr = ip->dst_address.as_u32 = m->local_addr.as_u32;
 614
 615       u = nat_user_get_or_create (sm, &m->local_addr, m->fib_index,
 616                                   thread_index);
 617       if (!u)
 618         {
 619           b->error = node->errors[NAT_OUT2IN_ED_ERROR_CANNOT_CREATE_USER];
 620           nat_elog_warn ("create NAT user failed");
 621           return 0;
 622         }
 623
 624       /* Create a new session */
 625       s = nat_ed_session_alloc (sm, u, thread_index, now);
 626       if (!s)
 627         {
 628           b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_USER_SESS_EXCEEDED];
 629           nat44_delete_user_with_no_session (sm, u, thread_index);
 630           nat_elog_warn ("create NAT session failed");
 631           return 0;
 632         }
 633
 634       s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 635       s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 636       s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 637       s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 638       s->out2in.addr.as_u32 = old_addr;
 639       s->out2in.fib_index = rx_fib_index;
 640       s->in2out.addr.as_u32 = new_addr;
 641       s->in2out.fib_index = m->fib_index;
 642       s->in2out.port = s->out2in.port = ip->protocol;
 643       user_session_increment (sm, u, 1);
 644
 645       /* Add to lookup tables */
 646       s_kv.value = s - tsm->sessions;
 647       if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &s_kv, 1))
 648         nat_elog_notice ("out2in key add failed");
 649
 650       make_ed_kv (&s_kv, &ip->dst_address, &ip->src_address, ip->protocol,
 651                   m->fib_index, 0, 0);
 652       s_kv.value = s - tsm->sessions;
 653       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &s_kv, 1))
 654         nat_elog_notice ("in2out key add failed");
 655     }
 656
 657   /* Update IP checksum */
 658   sum = ip->checksum;
 659   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
 660   ip->checksum = ip_csum_fold (sum);
 661
 662   vnet_buffer (b)->sw_if_index[VLIB_TX] = s->in2out.fib_index;
 663
 664   /* Accounting */
 665   nat44_session_update_counters (s, now, vlib_buffer_length_in_chain (vm, b),
 666                                  thread_index);
 667   /* Per-user LRU list maintenance */
 668   nat44_session_update_lru (sm, s, thread_index);
 669
 670   return s;
 671 }
 672
 673 static inline uword
 674 nat44_ed_out2in_fast_path_node_fn_inline (vlib_main_t * vm,
 675                                           vlib_node_runtime_t * node,
 676                                           vlib_frame_t * frame)
 677 {
 678   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
 679   nat_next_t next_index;
 680   snat_main_t *sm = &snat_main;
 681   f64 now = vlib_time_now (vm);
 682   u32 thread_index = vm->thread_index;
 683   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 684   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 685     0, fragments = 0;
 686
 687   stats_node_index = sm->ed_out2in_node_index;
 688
 689   from = vlib_frame_vector_args (frame);
 690   n_left_from = frame->n_vectors;
 691   next_index = node->cached_next_index;
 692
 693   while (n_left_from > 0)
 694     {
 695       u32 n_left_to_next;
 696
 697       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 698
 699       while (n_left_from > 0 && n_left_to_next > 0)
 700         {
 701           u32 bi0;
 702           vlib_buffer_t *b0;
 703           u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
 704             new_addr0;
 705           u16 old_port0, new_port0;
 706           ip4_header_t *ip0;
 707           udp_header_t *udp0;
 708           tcp_header_t *tcp0;
 709           snat_session_t *s0 = 0;
 710           clib_bihash_kv_16_8_t kv0, value0;
 711           ip_csum_t sum0;
 712
 713           /* speculatively enqueue b0 to the current next frame */
 714           bi0 = from[0];
 715           to_next[0] = bi0;
 716           from += 1;
 717           to_next += 1;
 718           n_left_from -= 1;
 719           n_left_to_next -= 1;
 720
 721           b0 = vlib_get_buffer (vm, bi0);
 722           next0 = vnet_buffer2 (b0)->nat.arc_next;
 723
 724           vnet_buffer (b0)->snat.flags = 0;
 725           ip0 = vlib_buffer_get_current (b0);
 726
 727           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 728           rx_fib_index0 =
 729             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 730                                                  sw_if_index0);
 731
 732           if (PREDICT_FALSE (ip0->ttl == 1))
 733             {
 734               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 735               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 736                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 737                                            0);
 738               next0 = NAT_NEXT_ICMP_ERROR;
 739               goto trace0;
 740             }
 741
 742           udp0 = ip4_next_header (ip0);
 743           tcp0 = (tcp_header_t *) udp0;
 744           proto0 = ip_proto_to_snat_proto (ip0->protocol);
 745
 746           if (PREDICT_FALSE (proto0 == ~0))
 747             {
 748               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 749               goto trace0;
 750             }
 751
 752           if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
 753             {
 754               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 755               goto trace0;
 756             }
 757
 758           make_ed_kv (&kv0, &ip0->dst_address, &ip0->src_address,
 759                       ip0->protocol, rx_fib_index0,
 760                       vnet_buffer (b0)->ip.reass.l4_dst_port,
 761                       vnet_buffer (b0)->ip.reass.l4_src_port);
 762
 763           if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv0, &value0))
 764             {
 765               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 766               goto trace0;
 767             }
 768           s0 = pool_elt_at_index (tsm->sessions, value0.value);
 769
 770           if (s0->tcp_close_timestamp)
 771             {
 772               if (now >= s0->tcp_close_timestamp)
 773                 {
 774                   // session is closed, go slow path
 775                   next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 776                 }
 777               else
 778                 {
 779                   // session in transitory timeout, drop
 780                   b0->error = node->errors[NAT_OUT2IN_ED_ERROR_TCP_CLOSED];
 781                   next0 = NAT_NEXT_DROP;
 782                 }
 783               goto trace0;
 784             }
 785
 786           // drop if session expired
 787           u64 sess_timeout_time;
 788           sess_timeout_time = s0->last_heard +
 789             (f64) nat44_session_get_timeout (sm, s0);
 790           if (now >= sess_timeout_time)
 791             {
 792               // session is closed, go slow path
 793               nat_free_session_data (sm, s0, thread_index, 0);
 794               nat44_delete_session (sm, s0, thread_index);
 795               next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
 796               goto trace0;
 797             }
 798           //
 799
 800           old_addr0 = ip0->dst_address.as_u32;
 801           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
 802           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
 803
 804           sum0 = ip0->checksum;
 805           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 806                                  dst_address);
 807           if (PREDICT_FALSE (is_twice_nat_session (s0)))
 808             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 809                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
 810                                    src_address);
 811           ip0->checksum = ip_csum_fold (sum0);
 812
 813           old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
 814
 815           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
 816             {
 817               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 818                 {
 819                   new_port0 = udp0->dst_port = s0->in2out.port;
 820                   sum0 = tcp0->checksum;
 821                   sum0 =
 822                     ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 823                                     dst_address);
 824                   sum0 =
 825                     ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 826                                     length);
 827                   if (is_twice_nat_session (s0))
 828                     {
 829                       sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 830                                              s0->ext_host_nat_addr.as_u32,
 831                                              ip4_header_t, dst_address);
 832                       sum0 =
 833                         ip_csum_update (sum0,
 834                                         vnet_buffer (b0)->ip.
 835                                         reass.l4_src_port,
 836                                         s0->ext_host_nat_port, ip4_header_t,
 837                                         length);
 838                       tcp0->src_port = s0->ext_host_nat_port;
 839                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 840                     }
 841                   tcp0->checksum = ip_csum_fold (sum0);
 842                 }
 843               tcp_packets++;
 844               if (nat44_set_tcp_session_state_o2i
 845                   (sm, now, s0,
 846                    vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags,
 847                    vnet_buffer (b0)->ip.reass.tcp_ack_number,
 848                    vnet_buffer (b0)->ip.reass.tcp_seq_number, thread_index))
 849                 goto trace0;
 850             }
 851           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
 852                    && udp0->checksum)
 853             {
 854               new_port0 = udp0->dst_port = s0->in2out.port;
 855               sum0 = udp0->checksum;
 856               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 857                                      dst_address);
 858               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 859                                      length);
 860               if (PREDICT_FALSE (is_twice_nat_session (s0)))
 861                 {
 862                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 863                                          s0->ext_host_nat_addr.as_u32,
 864                                          ip4_header_t, dst_address);
 865                   sum0 =
 866                     ip_csum_update (sum0,
 867                                     vnet_buffer (b0)->ip.reass.l4_src_port,
 868                                     s0->ext_host_nat_port, ip4_header_t,
 869                                     length);
 870                   udp0->src_port = s0->ext_host_nat_port;
 871                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 872                 }
 873               udp0->checksum = ip_csum_fold (sum0);
 874               udp_packets++;
 875             }
 876           else
 877             {
 878               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 879                 {
 880                   new_port0 = udp0->dst_port = s0->in2out.port;
 881                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
 882                     {
 883                       udp0->src_port = s0->ext_host_nat_port;
 884                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 885                     }
 886                 }
 887               udp_packets++;
 888             }
 889
 890           /* Accounting */
 891           nat44_session_update_counters (s0, now,
 892                                          vlib_buffer_length_in_chain (vm, b0),
 893                                          thread_index);
 894           /* Per-user LRU list maintenance */
 895           nat44_session_update_lru (sm, s0, thread_index);
 896
 897         trace0:
 898           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 899                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 900             {
 901               nat44_ed_out2in_trace_t *t =
 902                 vlib_add_trace (vm, node, b0, sizeof (*t));
 903               t->sw_if_index = sw_if_index0;
 904               t->next_index = next0;
 905               t->is_slow_path = 0;
 906
 907               if (s0)
 908                 t->session_index = s0 - tsm->sessions;
 909               else
 910                 t->session_index = ~0;
 911             }
 912
 913           pkts_processed += next0 == vnet_buffer2 (b0)->nat.arc_next;
 914           /* verify speculative enqueue, maybe switch current next frame */
 915           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 916                                            to_next, n_left_to_next,
 917                                            bi0, next0);
 918         }
 919
 920       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 921     }
 922
 923   vlib_node_increment_counter (vm, stats_node_index,
 924                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
 925                                pkts_processed);
 926   vlib_node_increment_counter (vm, stats_node_index,
 927                                NAT_OUT2IN_ED_ERROR_TCP_PACKETS, tcp_packets);
 928   vlib_node_increment_counter (vm, stats_node_index,
 929                                NAT_OUT2IN_ED_ERROR_UDP_PACKETS, udp_packets);
 930   vlib_node_increment_counter (vm, stats_node_index,
 931                                NAT_OUT2IN_ED_ERROR_ICMP_PACKETS,
 932                                icmp_packets);
 933   vlib_node_increment_counter (vm, stats_node_index,
 934                                NAT_OUT2IN_ED_ERROR_OTHER_PACKETS,
 935                                other_packets);
 936   vlib_node_increment_counter (vm, stats_node_index,
 937                                NAT_OUT2IN_ED_ERROR_FRAGMENTS, fragments);
 938   return frame->n_vectors;
 939 }
 940
 941 static inline uword
 942 nat44_ed_out2in_slow_path_node_fn_inline (vlib_main_t * vm,
 943                                           vlib_node_runtime_t * node,
 944                                           vlib_frame_t * frame)
 945 {
 946   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
 947   nat_next_t next_index;
 948   snat_main_t *sm = &snat_main;
 949   f64 now = vlib_time_now (vm);
 950   u32 thread_index = vm->thread_index;
 951   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 952   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 953     0, fragments = 0;
 954
 955   stats_node_index = sm->ed_out2in_slowpath_node_index;
 956
 957   from = vlib_frame_vector_args (frame);
 958   n_left_from = frame->n_vectors;
 959   next_index = node->cached_next_index;
 960
 961   while (n_left_from > 0)
 962     {
 963       u32 n_left_to_next;
 964
 965       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 966
 967       while (n_left_from > 0 && n_left_to_next > 0)
 968         {
 969           u32 bi0;
 970           vlib_buffer_t *b0;
 971           u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
 972             new_addr0;
 973           u16 old_port0, new_port0;
 974           ip4_header_t *ip0;
 975           udp_header_t *udp0;
 976           tcp_header_t *tcp0;
 977           icmp46_header_t *icmp0;
 978           snat_session_t *s0 = 0;
 979           clib_bihash_kv_16_8_t kv0, value0;
 980           ip_csum_t sum0;
 981           snat_session_key_t e_key0, l_key0;
 982           lb_nat_type_t lb_nat0;
 983           twice_nat_type_t twice_nat0;
 984           u8 identity_nat0;
 985
 986           /* speculatively enqueue b0 to the current next frame */
 987           bi0 = from[0];
 988           to_next[0] = bi0;
 989           from += 1;
 990           to_next += 1;
 991           n_left_from -= 1;
 992           n_left_to_next -= 1;
 993
 994           b0 = vlib_get_buffer (vm, bi0);
 995           next0 = vnet_buffer2 (b0)->nat.arc_next;
 996
 997           vnet_buffer (b0)->snat.flags = 0;
 998           ip0 = vlib_buffer_get_current (b0);
 999
1000           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1001           rx_fib_index0 =
1002             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
1003                                                  sw_if_index0);
1004
1005           if (PREDICT_FALSE (ip0->ttl == 1))
1006             {
1007               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1008               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1009                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1010                                            0);
1011               next0 = NAT_NEXT_ICMP_ERROR;
1012               goto trace0;
1013             }
1014
1015           udp0 = ip4_next_header (ip0);
1016           tcp0 = (tcp_header_t *) udp0;
1017           icmp0 = (icmp46_header_t *) udp0;
1018           proto0 = ip_proto_to_snat_proto (ip0->protocol);
1019
1020           if (PREDICT_FALSE (proto0 == ~0))
1021             {
1022               s0 =
1023                 nat44_ed_out2in_unknown_proto (sm, b0, ip0, rx_fib_index0,
1024                                                thread_index, now, vm, node);
1025               if (!sm->forwarding_enabled)
1026                 {
1027                   if (!s0)
1028                     next0 = NAT_NEXT_DROP;
1029                 }
1030               other_packets++;
1031               goto trace0;
1032             }
1033
1034           if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1035             {
1036               next0 = icmp_out2in_ed_slow_path
1037                 (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1038                  next0, now, thread_index, &s0);
1039               icmp_packets++;
1040               goto trace0;
1041             }
1042
1043           make_ed_kv (&kv0, &ip0->dst_address, &ip0->src_address,
1044                       ip0->protocol, rx_fib_index0,
1045                       vnet_buffer (b0)->ip.reass.l4_dst_port,
1046                       vnet_buffer (b0)->ip.reass.l4_src_port);
1047
1048           s0 = NULL;
1049           if (!clib_bihash_search_16_8 (&tsm->out2in_ed, &kv0, &value0))
1050             {
1051               s0 = pool_elt_at_index (tsm->sessions, value0.value);
1052
1053               if (s0->tcp_close_timestamp && now >= s0->tcp_close_timestamp)
1054                 {
1055                   nat_free_session_data (sm, s0, thread_index, 0);
1056                   nat44_delete_session (sm, s0, thread_index);
1057                   s0 = NULL;
1058                 }
1059             }
1060
1061           if (!s0)
1062             {
1063               /* Try to match static mapping by external address and port,
1064                  destination address and port in packet */
1065               e_key0.addr = ip0->dst_address;
1066               e_key0.port = vnet_buffer (b0)->ip.reass.l4_dst_port;
1067               e_key0.protocol = proto0;
1068               e_key0.fib_index = rx_fib_index0;
1069
1070               if (snat_static_mapping_match (sm, e_key0, &l_key0, 1, 0,
1071                                              &twice_nat0, &lb_nat0,
1072                                              &ip0->src_address,
1073                                              &identity_nat0))
1074                 {
1075                   /*
1076                    * Send DHCP packets to the ipv4 stack, or we won't
1077                    * be able to use dhcp client on the outside interface
1078                    */
1079                   if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_UDP
1080                                      && (vnet_buffer (b0)->ip.
1081                                          reass.l4_dst_port ==
1082                                          clib_host_to_net_u16
1083                                          (UDP_DST_PORT_dhcp_to_client))))
1084                     {
1085                       goto trace0;
1086                     }
1087
1088                   if (!sm->forwarding_enabled)
1089                     {
1090                       b0->error =
1091                         node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
1092                       next0 = NAT_NEXT_DROP;
1093                     }
1094                   else
1095                     {
1096                       if (next_src_nat (sm, ip0, ip0->protocol,
1097                                         vnet_buffer (b0)->ip.
1098                                         reass.l4_src_port,
1099                                         vnet_buffer (b0)->ip.
1100                                         reass.l4_dst_port, thread_index,
1101                                         rx_fib_index0))
1102                         {
1103                           next0 = NAT_NEXT_IN2OUT_ED_FAST_PATH;
1104                           goto trace0;
1105                         }
1106                       if (sm->num_workers > 1)
1107                         create_bypass_for_fwd_worker (sm, b0, ip0,
1108                                                       rx_fib_index0);
1109                       else
1110                         create_bypass_for_fwd (sm, b0, ip0, rx_fib_index0,
1111                                                thread_index);
1112                     }
1113                   goto trace0;
1114                 }
1115
1116               if (PREDICT_FALSE (identity_nat0))
1117                 goto trace0;
1118
1119               if ((proto0 == SNAT_PROTOCOL_TCP)
1120                   && !tcp_flags_is_init (vnet_buffer (b0)->ip.
1121                                          reass.icmp_type_or_tcp_flags))
1122                 {
1123                   b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
1124                   next0 = NAT_NEXT_DROP;
1125                   goto trace0;
1126                 }
1127
1128               /* Create session initiated by host from external network */
1129               s0 = create_session_for_static_mapping_ed (sm, b0, l_key0,
1130                                                          e_key0, node,
1131                                                          thread_index,
1132                                                          twice_nat0,
1133                                                          lb_nat0, now);
1134               if (!s0)
1135                 {
1136                   next0 = NAT_NEXT_DROP;
1137                   goto trace0;
1138                 }
1139             }
1140
1141           old_addr0 = ip0->dst_address.as_u32;
1142           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
1143           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
1144
1145           sum0 = ip0->checksum;
1146           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1147                                  dst_address);
1148           if (PREDICT_FALSE (is_twice_nat_session (s0)))
1149             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1150                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
1151                                    src_address);
1152           ip0->checksum = ip_csum_fold (sum0);
1153
1154           old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
1155
1156           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
1157             {
1158               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1159                 {
1160                   new_port0 = udp0->dst_port = s0->in2out.port;
1161                   sum0 = tcp0->checksum;
1162                   sum0 =
1163                     ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1164                                     dst_address);
1165                   sum0 =
1166                     ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1167                                     length);
1168                   if (is_twice_nat_session (s0))
1169                     {
1170                       sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1171                                              s0->ext_host_nat_addr.as_u32,
1172                                              ip4_header_t, dst_address);
1173                       sum0 =
1174                         ip_csum_update (sum0,
1175                                         vnet_buffer (b0)->ip.
1176                                         reass.l4_src_port,
1177                                         s0->ext_host_nat_port, ip4_header_t,
1178                                         length);
1179                       tcp0->src_port = s0->ext_host_nat_port;
1180                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1181                     }
1182                   tcp0->checksum = ip_csum_fold (sum0);
1183                 }
1184               tcp_packets++;
1185               if (nat44_set_tcp_session_state_o2i
1186                   (sm, now, s0,
1187                    vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags,
1188                    vnet_buffer (b0)->ip.reass.tcp_ack_number,
1189                    vnet_buffer (b0)->ip.reass.tcp_seq_number, thread_index))
1190                 goto trace0;
1191             }
1192           else if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment
1193                    && udp0->checksum)
1194             {
1195               new_port0 = udp0->dst_port = s0->in2out.port;
1196               sum0 = udp0->checksum;
1197               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1198                                      dst_address);
1199               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1200                                      length);
1201               if (PREDICT_FALSE (is_twice_nat_session (s0)))
1202                 {
1203                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1204                                          s0->ext_host_nat_addr.as_u32,
1205                                          ip4_header_t, dst_address);
1206                   sum0 =
1207                     ip_csum_update (sum0,
1208                                     vnet_buffer (b0)->ip.reass.l4_src_port,
1209                                     s0->ext_host_nat_port, ip4_header_t,
1210                                     length);
1211                   udp0->src_port = s0->ext_host_nat_port;
1212                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1213                 }
1214               udp0->checksum = ip_csum_fold (sum0);
1215               udp_packets++;
1216             }
1217           else
1218             {
1219               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1220                 {
1221                   new_port0 = udp0->dst_port = s0->in2out.port;
1222                   if (PREDICT_FALSE (is_twice_nat_session (s0)))
1223                     {
1224                       udp0->src_port = s0->ext_host_nat_port;
1225                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1226                     }
1227                 }
1228               udp_packets++;
1229             }
1230
1231           /* Accounting */
1232           nat44_session_update_counters (s0, now,
1233                                          vlib_buffer_length_in_chain (vm, b0),
1234                                          thread_index);
1235           /* Per-user LRU list maintenance */
1236           nat44_session_update_lru (sm, s0, thread_index);
1237
1238         trace0:
1239           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1240                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1241             {
1242               nat44_ed_out2in_trace_t *t =
1243                 vlib_add_trace (vm, node, b0, sizeof (*t));
1244               t->sw_if_index = sw_if_index0;
1245               t->next_index = next0;
1246               t->is_slow_path = 1;
1247
1248               if (s0)
1249                 t->session_index = s0 - tsm->sessions;
1250               else
1251                 t->session_index = ~0;
1252             }
1253
1254           pkts_processed += next0 == vnet_buffer2 (b0)->nat.arc_next;
1255           /* verify speculative enqueue, maybe switch current next frame */
1256           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1257                                            to_next, n_left_to_next,
1258                                            bi0, next0);
1259         }
1260
1261       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1262     }
1263
1264   vlib_node_increment_counter (vm, stats_node_index,
1265                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
1266                                pkts_processed);
1267   vlib_node_increment_counter (vm, stats_node_index,
1268                                NAT_OUT2IN_ED_ERROR_TCP_PACKETS, tcp_packets);
1269   vlib_node_increment_counter (vm, stats_node_index,
1270                                NAT_OUT2IN_ED_ERROR_UDP_PACKETS, udp_packets);
1271   vlib_node_increment_counter (vm, stats_node_index,
1272                                NAT_OUT2IN_ED_ERROR_ICMP_PACKETS,
1273                                icmp_packets);
1274   vlib_node_increment_counter (vm, stats_node_index,
1275                                NAT_OUT2IN_ED_ERROR_OTHER_PACKETS,
1276                                other_packets);
1277   vlib_node_increment_counter (vm, stats_node_index,
1278                                NAT_OUT2IN_ED_ERROR_FRAGMENTS, fragments);
1279   return frame->n_vectors;
1280 }
1281
1282 VLIB_NODE_FN (nat44_ed_out2in_node) (vlib_main_t * vm,
1283                                      vlib_node_runtime_t * node,
1284                                      vlib_frame_t * frame)
1285 {
1286   return nat44_ed_out2in_fast_path_node_fn_inline (vm, node, frame);
1287 }
1288
1289 /* *INDENT-OFF* */
1290 VLIB_REGISTER_NODE (nat44_ed_out2in_node) = {
1291   .name = "nat44-ed-out2in",
1292   .vector_size = sizeof (u32),
1293   .sibling_of = "nat-default",
1294   .format_trace = format_nat44_ed_out2in_trace,
1295   .type = VLIB_NODE_TYPE_INTERNAL,
1296   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1297   .error_strings = nat_out2in_ed_error_strings,
1298   .runtime_data_bytes = sizeof (snat_runtime_t),
1299 };
1300 /* *INDENT-ON* */
1301
1302 VLIB_NODE_FN (nat44_ed_out2in_slowpath_node) (vlib_main_t * vm,
1303                                               vlib_node_runtime_t * node,
1304                                               vlib_frame_t * frame)
1305 {
1306   return nat44_ed_out2in_slow_path_node_fn_inline (vm, node, frame);
1307 }
1308
1309 /* *INDENT-OFF* */
1310 VLIB_REGISTER_NODE (nat44_ed_out2in_slowpath_node) = {
1311   .name = "nat44-ed-out2in-slowpath",
1312   .vector_size = sizeof (u32),
1313   .sibling_of = "nat-default",
1314   .format_trace = format_nat44_ed_out2in_trace,
1315   .type = VLIB_NODE_TYPE_INTERNAL,
1316   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1317   .error_strings = nat_out2in_ed_error_strings,
1318   .runtime_data_bytes = sizeof (snat_runtime_t),
1319 };
1320 /* *INDENT-ON* */
1321
1322 static u8 *
1323 format_nat_pre_trace (u8 * s, va_list * args)
1324 {
1325   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1326   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1327   nat_pre_trace_t *t = va_arg (*args, nat_pre_trace_t *);
1328   return format (s, "out2in next_index %d", t->next_index);
1329 }
1330
1331 VLIB_NODE_FN (nat_pre_out2in_node) (vlib_main_t * vm,
1332                                     vlib_node_runtime_t * node,
1333                                     vlib_frame_t * frame)
1334 {
1335   return nat_pre_node_fn_inline (vm, node, frame,
1336                                  NAT_NEXT_OUT2IN_ED_FAST_PATH);
1337 }
1338
1339 /* *INDENT-OFF* */
1340 VLIB_REGISTER_NODE (nat_pre_out2in_node) = {
1341   .name = "nat-pre-out2in",
1342   .vector_size = sizeof (u32),
1343   .sibling_of = "nat-default",
1344   .format_trace = format_nat_pre_trace,
1345   .type = VLIB_NODE_TYPE_INTERNAL,
1346   .n_errors = 0,
1347  };
1348 /* *INDENT-ON* */
1349
1350 /*
1351  * fd.io coding-style-patch-verification: ON
1352  *
1353  * Local Variables:
1354  * eval: (c-set-style "gnu")
1355  * End:
1356  */