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_reass.h>
  31 #include <nat/nat_inlines.h>
  32
  33 #define foreach_nat_out2in_ed_error                     \
  34 _(UNSUPPORTED_PROTOCOL, "Unsupported protocol")         \
  35 _(OUT2IN_PACKETS, "Good out2in packets processed")      \
  36 _(OUT_OF_PORTS, "Out of ports")                         \
  37 _(BAD_ICMP_TYPE, "unsupported ICMP type")               \
  38 _(NO_TRANSLATION, "No translation")                     \
  39 _(MAX_SESSIONS_EXCEEDED, "Maximum sessions exceeded")   \
  40 _(DROP_FRAGMENT, "Drop fragment")                       \
  41 _(MAX_REASS, "Maximum reassemblies exceeded")           \
  42 _(MAX_FRAG, "Maximum fragments per reassembly exceeded")\
  43 _(NON_SYN, "non-SYN packet try to create session")
  44
  45 typedef enum
  46 {
  47 #define _(sym,str) NAT_OUT2IN_ED_ERROR_##sym,
  48   foreach_nat_out2in_ed_error
  49 #undef _
  50     NAT_OUT2IN_ED_N_ERROR,
  51 } nat_out2in_ed_error_t;
  52
  53 static char *nat_out2in_ed_error_strings[] = {
  54 #define _(sym,string) string,
  55   foreach_nat_out2in_ed_error
  56 #undef _
  57 };
  58
  59 typedef enum
  60 {
  61   NAT44_ED_OUT2IN_NEXT_DROP,
  62   NAT44_ED_OUT2IN_NEXT_LOOKUP,
  63   NAT44_ED_OUT2IN_NEXT_ICMP_ERROR,
  64   NAT44_ED_OUT2IN_NEXT_IN2OUT,
  65   NAT44_ED_OUT2IN_NEXT_SLOW_PATH,
  66   NAT44_ED_OUT2IN_NEXT_REASS,
  67   NAT44_ED_OUT2IN_N_NEXT,
  68 } nat44_ed_out2in_next_t;
  69
  70 typedef struct
  71 {
  72   u32 sw_if_index;
  73   u32 next_index;
  74   u32 session_index;
  75   u32 is_slow_path;
  76 } nat44_ed_out2in_trace_t;
  77
  78 vlib_node_registration_t nat44_ed_out2in_node;
  79 vlib_node_registration_t nat44_ed_out2in_slowpath_node;
  80 vlib_node_registration_t nat44_ed_out2in_reass_node;
  81
  82 static u8 *
  83 format_nat44_ed_out2in_trace (u8 * s, va_list * args)
  84 {
  85   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  86   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  87   nat44_ed_out2in_trace_t *t = va_arg (*args, nat44_ed_out2in_trace_t *);
  88   char *tag;
  89
  90   tag =
  91     t->is_slow_path ? "NAT44_OUT2IN_ED_SLOW_PATH" :
  92     "NAT44_OUT2IN_ED_FAST_PATH";
  93
  94   s = format (s, "%s: sw_if_index %d, next index %d, session %d", tag,
  95               t->sw_if_index, t->next_index, t->session_index);
  96
  97   return s;
  98 }
  99
 100 static inline u32
 101 icmp_out2in_ed_slow_path (snat_main_t * sm, vlib_buffer_t * b0,
 102                           ip4_header_t * ip0, icmp46_header_t * icmp0,
 103                           u32 sw_if_index0, u32 rx_fib_index0,
 104                           vlib_node_runtime_t * node, u32 next0, f64 now,
 105                           u32 thread_index, snat_session_t ** p_s0)
 106 {
 107   next0 = icmp_out2in (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
 108                        next0, thread_index, p_s0, 0);
 109   snat_session_t *s0 = *p_s0;
 110   if (PREDICT_TRUE (next0 != NAT44_ED_OUT2IN_NEXT_DROP && s0))
 111     {
 112       /* Accounting */
 113       nat44_session_update_counters (s0, now,
 114                                      vlib_buffer_length_in_chain
 115                                      (sm->vlib_main, b0));
 116       /* Per-user LRU list maintenance */
 117       nat44_session_update_lru (sm, s0, thread_index);
 118     }
 119   return next0;
 120 }
 121
 122 int
 123 nat44_o2i_ed_is_idle_session_cb (clib_bihash_kv_16_8_t * kv, void *arg)
 124 {
 125   snat_main_t *sm = &snat_main;
 126   nat44_is_idle_session_ctx_t *ctx = arg;
 127   snat_session_t *s;
 128   u64 sess_timeout_time;
 129   nat_ed_ses_key_t ed_key;
 130   clib_bihash_kv_16_8_t ed_kv;
 131   int i;
 132   snat_address_t *a;
 133   snat_session_key_t key;
 134   snat_main_per_thread_data_t *tsm = vec_elt_at_index (sm->per_thread_data,
 135                                                        ctx->thread_index);
 136
 137   s = pool_elt_at_index (tsm->sessions, kv->value);
 138   sess_timeout_time = s->last_heard + (f64) nat44_session_get_timeout (sm, s);
 139   if (ctx->now >= sess_timeout_time)
 140     {
 141       ed_key.l_addr = s->in2out.addr;
 142       ed_key.r_addr = s->ext_host_addr;
 143       ed_key.fib_index = s->in2out.fib_index;
 144       if (snat_is_unk_proto_session (s))
 145         {
 146           ed_key.proto = s->in2out.port;
 147           ed_key.r_port = 0;
 148           ed_key.l_port = 0;
 149         }
 150       else
 151         {
 152           ed_key.proto = snat_proto_to_ip_proto (s->in2out.protocol);
 153           ed_key.l_port = s->in2out.port;
 154           ed_key.r_port = s->ext_host_port;
 155         }
 156       if (is_twice_nat_session (s))
 157         {
 158           ed_key.r_addr = s->ext_host_nat_addr;
 159           ed_key.r_port = s->ext_host_nat_port;
 160         }
 161       ed_kv.key[0] = ed_key.as_u64[0];
 162       ed_kv.key[1] = ed_key.as_u64[1];
 163       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &ed_kv, 0))
 164         nat_log_warn ("in2out_ed key del failed");
 165
 166       if (snat_is_unk_proto_session (s))
 167         goto delete;
 168
 169       snat_ipfix_logging_nat44_ses_delete (s->in2out.addr.as_u32,
 170                                            s->out2in.addr.as_u32,
 171                                            s->in2out.protocol,
 172                                            s->in2out.port,
 173                                            s->out2in.port,
 174                                            s->in2out.fib_index);
 175
 176       if (is_twice_nat_session (s))
 177         {
 178           for (i = 0; i < vec_len (sm->twice_nat_addresses); i++)
 179             {
 180               key.protocol = s->in2out.protocol;
 181               key.port = s->ext_host_nat_port;
 182               a = sm->twice_nat_addresses + i;
 183               if (a->addr.as_u32 == s->ext_host_nat_addr.as_u32)
 184                 {
 185                   snat_free_outside_address_and_port (sm->twice_nat_addresses,
 186                                                       ctx->thread_index,
 187                                                       &key);
 188                   break;
 189                 }
 190             }
 191         }
 192
 193       if (snat_is_session_static (s))
 194         goto delete;
 195
 196       snat_free_outside_address_and_port (sm->addresses, ctx->thread_index,
 197                                           &s->out2in);
 198     delete:
 199       nat44_delete_session (sm, s, ctx->thread_index);
 200       return 1;
 201     }
 202
 203   return 0;
 204 }
 205
 206 static snat_session_t *
 207 create_session_for_static_mapping_ed (snat_main_t * sm,
 208                                       vlib_buffer_t * b,
 209                                       snat_session_key_t l_key,
 210                                       snat_session_key_t e_key,
 211                                       vlib_node_runtime_t * node,
 212                                       u32 thread_index,
 213                                       twice_nat_type_t twice_nat,
 214                                       lb_nat_type_t lb_nat, f64 now)
 215 {
 216   snat_session_t *s;
 217   snat_user_t *u;
 218   ip4_header_t *ip;
 219   udp_header_t *udp;
 220   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 221   clib_bihash_kv_16_8_t kv;
 222   snat_session_key_t eh_key;
 223   nat44_is_idle_session_ctx_t ctx;
 224
 225   if (PREDICT_FALSE (maximum_sessions_exceeded (sm, thread_index)))
 226     {
 227       b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 228       nat_log_notice ("maximum sessions exceeded");
 229       return 0;
 230     }
 231
 232   u = nat_user_get_or_create (sm, &l_key.addr, l_key.fib_index, thread_index);
 233   if (!u)
 234     {
 235       nat_log_warn ("create NAT user failed");
 236       return 0;
 237     }
 238
 239   s = nat_ed_session_alloc (sm, u, thread_index, now);
 240   if (!s)
 241     {
 242       nat44_delete_user_with_no_session (sm, u, thread_index);
 243       nat_log_warn ("create NAT session failed");
 244       return 0;
 245     }
 246
 247   ip = vlib_buffer_get_current (b);
 248   udp = ip4_next_header (ip);
 249
 250   s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 251   s->ext_host_port = e_key.protocol == SNAT_PROTOCOL_ICMP ? 0 : udp->src_port;
 252   s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 253   if (lb_nat)
 254     s->flags |= SNAT_SESSION_FLAG_LOAD_BALANCING;
 255   if (lb_nat == AFFINITY_LB_NAT)
 256     s->flags |= SNAT_SESSION_FLAG_AFFINITY;
 257   s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 258   s->out2in = e_key;
 259   s->in2out = l_key;
 260   s->in2out.protocol = s->out2in.protocol;
 261   user_session_increment (sm, u, 1);
 262
 263   /* Add to lookup tables */
 264   make_ed_kv (&kv, &e_key.addr, &s->ext_host_addr, ip->protocol,
 265               e_key.fib_index, e_key.port, s->ext_host_port);
 266   kv.value = s - tsm->sessions;
 267   ctx.now = now;
 268   ctx.thread_index = thread_index;
 269   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->out2in_ed, &kv,
 270                                                nat44_o2i_ed_is_idle_session_cb,
 271                                                &ctx))
 272     nat_log_notice ("out2in-ed key add failed");
 273
 274   if (twice_nat == TWICE_NAT || (twice_nat == TWICE_NAT_SELF &&
 275                                  ip->src_address.as_u32 == l_key.addr.as_u32))
 276     {
 277       eh_key.protocol = e_key.protocol;
 278       if (snat_alloc_outside_address_and_port (sm->twice_nat_addresses, 0,
 279                                                thread_index, &eh_key,
 280                                                sm->port_per_thread,
 281                                                tsm->snat_thread_index))
 282         {
 283           b->error = node->errors[NAT_OUT2IN_ED_ERROR_OUT_OF_PORTS];
 284           nat44_delete_session (sm, s, thread_index);
 285           if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &kv, 0))
 286             nat_log_notice ("out2in-ed key del failed");
 287           return 0;
 288         }
 289       s->ext_host_nat_addr.as_u32 = eh_key.addr.as_u32;
 290       s->ext_host_nat_port = eh_key.port;
 291       s->flags |= SNAT_SESSION_FLAG_TWICE_NAT;
 292       make_ed_kv (&kv, &l_key.addr, &s->ext_host_nat_addr, ip->protocol,
 293                   l_key.fib_index, l_key.port, s->ext_host_nat_port);
 294     }
 295   else
 296     {
 297       make_ed_kv (&kv, &l_key.addr, &s->ext_host_addr, ip->protocol,
 298                   l_key.fib_index, l_key.port, s->ext_host_port);
 299     }
 300   kv.value = s - tsm->sessions;
 301   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->in2out_ed, &kv,
 302                                                nat44_i2o_ed_is_idle_session_cb,
 303                                                &ctx))
 304     nat_log_notice ("in2out-ed key add failed");
 305
 306   return s;
 307 }
 308
 309 static_always_inline int
 310 icmp_get_ed_key (ip4_header_t * ip0, nat_ed_ses_key_t * p_key0)
 311 {
 312   icmp46_header_t *icmp0;
 313   nat_ed_ses_key_t key0;
 314   icmp_echo_header_t *echo0, *inner_echo0 = 0;
 315   ip4_header_t *inner_ip0;
 316   void *l4_header = 0;
 317   icmp46_header_t *inner_icmp0;
 318
 319   icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
 320   echo0 = (icmp_echo_header_t *) (icmp0 + 1);
 321
 322   if (!icmp_is_error_message (icmp0))
 323     {
 324       key0.proto = IP_PROTOCOL_ICMP;
 325       key0.l_addr = ip0->dst_address;
 326       key0.r_addr = ip0->src_address;
 327       key0.l_port = echo0->identifier;
 328       key0.r_port = 0;
 329     }
 330   else
 331     {
 332       inner_ip0 = (ip4_header_t *) (echo0 + 1);
 333       l4_header = ip4_next_header (inner_ip0);
 334       key0.proto = inner_ip0->protocol;
 335       key0.l_addr = inner_ip0->src_address;
 336       key0.r_addr = inner_ip0->dst_address;
 337       switch (ip_proto_to_snat_proto (inner_ip0->protocol))
 338         {
 339         case SNAT_PROTOCOL_ICMP:
 340           inner_icmp0 = (icmp46_header_t *) l4_header;
 341           inner_echo0 = (icmp_echo_header_t *) (inner_icmp0 + 1);
 342           key0.l_port = inner_echo0->identifier;
 343           key0.r_port = 0;
 344           break;
 345         case SNAT_PROTOCOL_UDP:
 346         case SNAT_PROTOCOL_TCP:
 347           key0.l_port = ((tcp_udp_header_t *) l4_header)->src_port;
 348           key0.r_port = ((tcp_udp_header_t *) l4_header)->dst_port;
 349           break;
 350         default:
 351           return -1;
 352         }
 353     }
 354   *p_key0 = key0;
 355   return 0;
 356 }
 357
 358 static int
 359 next_src_nat (snat_main_t * sm, ip4_header_t * ip, u8 proto, u16 src_port,
 360               u16 dst_port, u32 thread_index, u32 rx_fib_index)
 361 {
 362   clib_bihash_kv_16_8_t kv, value;
 363   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 364
 365   make_ed_kv (&kv, &ip->src_address, &ip->dst_address, proto,
 366               rx_fib_index, src_port, dst_port);
 367   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 368     return 1;
 369
 370   return 0;
 371 }
 372
 373 static void
 374 create_bypass_for_fwd (snat_main_t * sm, ip4_header_t * ip, u32 rx_fib_index,
 375                        u32 thread_index)
 376 {
 377   nat_ed_ses_key_t key;
 378   clib_bihash_kv_16_8_t kv, value;
 379   udp_header_t *udp;
 380   snat_user_t *u;
 381   snat_session_t *s = 0;
 382   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 383   f64 now = vlib_time_now (sm->vlib_main);
 384
 385   if (ip->protocol == IP_PROTOCOL_ICMP)
 386     {
 387       if (icmp_get_ed_key (ip, &key))
 388         return;
 389     }
 390   else if (ip->protocol == IP_PROTOCOL_UDP || ip->protocol == IP_PROTOCOL_TCP)
 391     {
 392       udp = ip4_next_header (ip);
 393       key.r_addr = ip->src_address;
 394       key.l_addr = ip->dst_address;
 395       key.proto = ip->protocol;
 396       key.l_port = udp->dst_port;
 397       key.r_port = udp->src_port;
 398     }
 399   else
 400     {
 401       key.r_addr = ip->src_address;
 402       key.l_addr = ip->dst_address;
 403       key.proto = ip->protocol;
 404       key.l_port = key.r_port = 0;
 405     }
 406   key.fib_index = 0;
 407   kv.key[0] = key.as_u64[0];
 408   kv.key[1] = key.as_u64[1];
 409
 410   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
 411     {
 412       s = pool_elt_at_index (tsm->sessions, value.value);
 413     }
 414   else
 415     {
 416       if (PREDICT_FALSE (maximum_sessions_exceeded (sm, thread_index)))
 417         return;
 418
 419       u = nat_user_get_or_create (sm, &ip->dst_address, sm->inside_fib_index,
 420                                   thread_index);
 421       if (!u)
 422         {
 423           nat_log_warn ("create NAT user failed");
 424           return;
 425         }
 426
 427       s = nat_ed_session_alloc (sm, u, thread_index, now);
 428       if (!s)
 429         {
 430           nat44_delete_user_with_no_session (sm, u, thread_index);
 431           nat_log_warn ("create NAT session failed");
 432           return;
 433         }
 434
 435       s->ext_host_addr = key.r_addr;
 436       s->ext_host_port = key.r_port;
 437       s->flags |= SNAT_SESSION_FLAG_FWD_BYPASS;
 438       s->out2in.addr = key.l_addr;
 439       s->out2in.port = key.l_port;
 440       s->out2in.protocol = ip_proto_to_snat_proto (key.proto);
 441       s->out2in.fib_index = 0;
 442       s->in2out = s->out2in;
 443       user_session_increment (sm, u, 0);
 444
 445       kv.value = s - tsm->sessions;
 446       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &kv, 1))
 447         nat_log_notice ("in2out_ed key add failed");
 448     }
 449
 450   if (ip->protocol == IP_PROTOCOL_TCP)
 451     {
 452       tcp_header_t *tcp = ip4_next_header (ip);
 453       if (nat44_set_tcp_session_state_o2i (sm, s, tcp, thread_index))
 454         return;
 455     }
 456
 457   /* Accounting */
 458   nat44_session_update_counters (s, now, 0);
 459   /* Per-user LRU list maintenance */
 460   nat44_session_update_lru (sm, s, thread_index);
 461 }
 462
 463 u32
 464 icmp_match_out2in_ed (snat_main_t * sm, vlib_node_runtime_t * node,
 465                       u32 thread_index, vlib_buffer_t * b, ip4_header_t * ip,
 466                       u8 * p_proto, snat_session_key_t * p_value,
 467                       u8 * p_dont_translate, void *d, void *e)
 468 {
 469   u32 next = ~0, sw_if_index, rx_fib_index;
 470   icmp46_header_t *icmp;
 471   nat_ed_ses_key_t key;
 472   clib_bihash_kv_16_8_t kv, value;
 473   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 474   snat_session_t *s = 0;
 475   u8 dont_translate = 0, is_addr_only, identity_nat;
 476   snat_session_key_t e_key, l_key;
 477
 478   icmp = (icmp46_header_t *) ip4_next_header (ip);
 479   sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
 480   rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 481
 482   if (icmp_get_ed_key (ip, &key))
 483     {
 484       b->error = node->errors[NAT_OUT2IN_ED_ERROR_UNSUPPORTED_PROTOCOL];
 485       next = NAT44_ED_OUT2IN_NEXT_DROP;
 486       goto out;
 487     }
 488   key.fib_index = rx_fib_index;
 489   kv.key[0] = key.as_u64[0];
 490   kv.key[1] = key.as_u64[1];
 491
 492   if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv, &value))
 493     {
 494       /* Try to match static mapping */
 495       e_key.addr = ip->dst_address;
 496       e_key.port = key.l_port;
 497       e_key.protocol = ip_proto_to_snat_proto (key.proto);
 498       e_key.fib_index = rx_fib_index;
 499       if (snat_static_mapping_match
 500           (sm, e_key, &l_key, 1, &is_addr_only, 0, 0, 0, &identity_nat))
 501         {
 502           if (!sm->forwarding_enabled)
 503             {
 504               /* Don't NAT packet aimed at the intfc address */
 505               if (PREDICT_FALSE (is_interface_addr (sm, node, sw_if_index,
 506                                                     ip->dst_address.as_u32)))
 507                 {
 508                   dont_translate = 1;
 509                   goto out;
 510                 }
 511               b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 512               next = NAT44_ED_OUT2IN_NEXT_DROP;
 513               goto out;
 514             }
 515           else
 516             {
 517               dont_translate = 1;
 518               if (next_src_nat (sm, ip, key.proto, key.l_port, key.r_port,
 519                                 thread_index, rx_fib_index))
 520                 {
 521                   next = NAT44_ED_OUT2IN_NEXT_IN2OUT;
 522                   goto out;
 523                 }
 524               create_bypass_for_fwd (sm, ip, rx_fib_index, thread_index);
 525               goto out;
 526             }
 527         }
 528
 529       if (PREDICT_FALSE (icmp->type != ICMP4_echo_reply &&
 530                          (icmp->type != ICMP4_echo_request || !is_addr_only)))
 531         {
 532           b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 533           next = NAT44_ED_OUT2IN_NEXT_DROP;
 534           goto out;
 535         }
 536
 537       if (PREDICT_FALSE (identity_nat))
 538         {
 539           dont_translate = 1;
 540           goto out;
 541         }
 542
 543       /* Create session initiated by host from external network */
 544       s = create_session_for_static_mapping_ed (sm, b, l_key, e_key, node,
 545                                                 thread_index, 0, 0,
 546                                                 vlib_time_now
 547                                                 (sm->vlib_main));
 548
 549       if (!s)
 550         {
 551           next = NAT44_ED_OUT2IN_NEXT_DROP;
 552           goto out;
 553         }
 554     }
 555   else
 556     {
 557       if (PREDICT_FALSE (icmp->type != ICMP4_echo_reply &&
 558                          icmp->type != ICMP4_echo_request &&
 559                          !icmp_is_error_message (icmp)))
 560         {
 561           b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
 562           next = NAT44_ED_OUT2IN_NEXT_DROP;
 563           goto out;
 564         }
 565
 566       s = pool_elt_at_index (tsm->sessions, value.value);
 567     }
 568
 569   *p_proto = ip_proto_to_snat_proto (key.proto);
 570 out:
 571   if (s)
 572     *p_value = s->in2out;
 573   *p_dont_translate = dont_translate;
 574   if (d)
 575     *(snat_session_t **) d = s;
 576   return next;
 577 }
 578
 579 static snat_session_t *
 580 nat44_ed_out2in_unknown_proto (snat_main_t * sm,
 581                                vlib_buffer_t * b,
 582                                ip4_header_t * ip,
 583                                u32 rx_fib_index,
 584                                u32 thread_index,
 585                                f64 now,
 586                                vlib_main_t * vm, vlib_node_runtime_t * node)
 587 {
 588   clib_bihash_kv_8_8_t kv, value;
 589   clib_bihash_kv_16_8_t s_kv, s_value;
 590   snat_static_mapping_t *m;
 591   u32 old_addr, new_addr;
 592   ip_csum_t sum;
 593   snat_session_t *s;
 594   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 595   snat_user_t *u;
 596
 597   old_addr = ip->dst_address.as_u32;
 598
 599   make_ed_kv (&s_kv, &ip->dst_address, &ip->src_address, ip->protocol,
 600               rx_fib_index, 0, 0);
 601
 602   if (!clib_bihash_search_16_8 (&tsm->out2in_ed, &s_kv, &s_value))
 603     {
 604       s = pool_elt_at_index (tsm->sessions, s_value.value);
 605       new_addr = ip->dst_address.as_u32 = s->in2out.addr.as_u32;
 606     }
 607   else
 608     {
 609       if (PREDICT_FALSE (maximum_sessions_exceeded (sm, thread_index)))
 610         {
 611           b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
 612           nat_log_notice ("maximum sessions exceeded");
 613           return 0;
 614         }
 615
 616       make_sm_kv (&kv, &ip->dst_address, 0, 0, 0);
 617       if (clib_bihash_search_8_8
 618           (&sm->static_mapping_by_external, &kv, &value))
 619         {
 620           b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 621           return 0;
 622         }
 623
 624       m = pool_elt_at_index (sm->static_mappings, value.value);
 625
 626       new_addr = ip->dst_address.as_u32 = m->local_addr.as_u32;
 627
 628       u = nat_user_get_or_create (sm, &m->local_addr, m->fib_index,
 629                                   thread_index);
 630       if (!u)
 631         {
 632           nat_log_warn ("create NAT user failed");
 633           return 0;
 634         }
 635
 636       /* Create a new session */
 637       s = nat_ed_session_alloc (sm, u, thread_index, now);
 638       if (!s)
 639         {
 640           nat44_delete_user_with_no_session (sm, u, thread_index);
 641           nat_log_warn ("create NAT session failed");
 642           return 0;
 643         }
 644
 645       s->ext_host_addr.as_u32 = ip->src_address.as_u32;
 646       s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
 647       s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 648       s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
 649       s->out2in.addr.as_u32 = old_addr;
 650       s->out2in.fib_index = rx_fib_index;
 651       s->in2out.addr.as_u32 = new_addr;
 652       s->in2out.fib_index = m->fib_index;
 653       s->in2out.port = s->out2in.port = ip->protocol;
 654       user_session_increment (sm, u, 1);
 655
 656       /* Add to lookup tables */
 657       s_kv.value = s - tsm->sessions;
 658       if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &s_kv, 1))
 659         nat_log_notice ("out2in key add failed");
 660
 661       make_ed_kv (&s_kv, &ip->dst_address, &ip->src_address, ip->protocol,
 662                   m->fib_index, 0, 0);
 663       s_kv.value = s - tsm->sessions;
 664       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &s_kv, 1))
 665         nat_log_notice ("in2out key add failed");
 666     }
 667
 668   /* Update IP checksum */
 669   sum = ip->checksum;
 670   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
 671   ip->checksum = ip_csum_fold (sum);
 672
 673   vnet_buffer (b)->sw_if_index[VLIB_TX] = s->in2out.fib_index;
 674
 675   /* Accounting */
 676   nat44_session_update_counters (s, now, vlib_buffer_length_in_chain (vm, b));
 677   /* Per-user LRU list maintenance */
 678   nat44_session_update_lru (sm, s, thread_index);
 679
 680   return s;
 681 }
 682
 683 static inline uword
 684 nat44_ed_out2in_node_fn_inline (vlib_main_t * vm,
 685                                 vlib_node_runtime_t * node,
 686                                 vlib_frame_t * frame, int is_slow_path)
 687 {
 688   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
 689   nat44_ed_out2in_next_t next_index;
 690   snat_main_t *sm = &snat_main;
 691   f64 now = vlib_time_now (vm);
 692   u32 thread_index = vm->thread_index;
 693   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 694
 695   stats_node_index = is_slow_path ? nat44_ed_out2in_slowpath_node.index :
 696     nat44_ed_out2in_node.index;
 697
 698   from = vlib_frame_vector_args (frame);
 699   n_left_from = frame->n_vectors;
 700   next_index = node->cached_next_index;
 701
 702   while (n_left_from > 0)
 703     {
 704       u32 n_left_to_next;
 705
 706       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 707
 708       while (n_left_from >= 4 && n_left_to_next >= 2)
 709         {
 710           u32 bi0, bi1;
 711           vlib_buffer_t *b0, *b1;
 712           u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
 713             new_addr0;
 714           u32 next1, sw_if_index1, rx_fib_index1, proto1, old_addr1,
 715             new_addr1;
 716           u16 old_port0, new_port0, old_port1, new_port1;
 717           ip4_header_t *ip0, *ip1;
 718           udp_header_t *udp0, *udp1;
 719           tcp_header_t *tcp0, *tcp1;
 720           icmp46_header_t *icmp0, *icmp1;
 721           snat_session_t *s0 = 0, *s1 = 0;
 722           clib_bihash_kv_16_8_t kv0, value0, kv1, value1;
 723           ip_csum_t sum0, sum1;
 724           snat_session_key_t e_key0, l_key0, e_key1, l_key1;
 725           lb_nat_type_t lb_nat0, lb_nat1;
 726           twice_nat_type_t twice_nat0, twice_nat1;
 727           u8 identity_nat0, identity_nat1;
 728
 729           /* Prefetch next iteration. */
 730           {
 731             vlib_buffer_t *p2, *p3;
 732
 733             p2 = vlib_get_buffer (vm, from[2]);
 734             p3 = vlib_get_buffer (vm, from[3]);
 735
 736             vlib_prefetch_buffer_header (p2, LOAD);
 737             vlib_prefetch_buffer_header (p3, LOAD);
 738
 739             CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE);
 740             CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE);
 741           }
 742
 743           /* speculatively enqueue b0 and b1 to the current next frame */
 744           to_next[0] = bi0 = from[0];
 745           to_next[1] = bi1 = from[1];
 746           from += 2;
 747           to_next += 2;
 748           n_left_from -= 2;
 749           n_left_to_next -= 2;
 750
 751           b0 = vlib_get_buffer (vm, bi0);
 752           b1 = vlib_get_buffer (vm, bi1);
 753
 754           next0 = NAT44_ED_OUT2IN_NEXT_LOOKUP;
 755           vnet_buffer (b0)->snat.flags = 0;
 756           ip0 = vlib_buffer_get_current (b0);
 757
 758           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 759           rx_fib_index0 =
 760             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 761                                                  sw_if_index0);
 762
 763           if (PREDICT_FALSE (ip0->ttl == 1))
 764             {
 765               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 766               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 767                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 768                                            0);
 769               next0 = NAT44_ED_OUT2IN_NEXT_ICMP_ERROR;
 770               goto trace00;
 771             }
 772
 773           udp0 = ip4_next_header (ip0);
 774           tcp0 = (tcp_header_t *) udp0;
 775           icmp0 = (icmp46_header_t *) udp0;
 776           proto0 = ip_proto_to_snat_proto (ip0->protocol);
 777
 778           if (is_slow_path)
 779             {
 780               if (PREDICT_FALSE (proto0 == ~0))
 781                 {
 782                   s0 =
 783                     nat44_ed_out2in_unknown_proto (sm, b0, ip0, rx_fib_index0,
 784                                                    thread_index, now, vm,
 785                                                    node);
 786                   if (!sm->forwarding_enabled)
 787                     {
 788                       if (!s0)
 789                         next0 = NAT44_ED_OUT2IN_NEXT_DROP;
 790                       goto trace00;
 791                     }
 792                 }
 793
 794               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
 795                 {
 796                   next0 = icmp_out2in_ed_slow_path
 797                     (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
 798                      next0, now, thread_index, &s0);
 799                   goto trace00;
 800                 }
 801             }
 802           else
 803             {
 804               if (PREDICT_FALSE (proto0 == ~0))
 805                 {
 806                   next0 = NAT44_ED_OUT2IN_NEXT_SLOW_PATH;
 807                   goto trace00;
 808                 }
 809
 810               if (ip4_is_fragment (ip0))
 811                 {
 812                   next0 = NAT44_ED_OUT2IN_NEXT_REASS;
 813                   goto trace00;
 814                 }
 815
 816               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
 817                 {
 818                   next0 = NAT44_ED_OUT2IN_NEXT_SLOW_PATH;
 819                   goto trace00;
 820                 }
 821             }
 822
 823           make_ed_kv (&kv0, &ip0->dst_address, &ip0->src_address,
 824                       ip0->protocol, rx_fib_index0, udp0->dst_port,
 825                       udp0->src_port);
 826
 827           if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv0, &value0))
 828             {
 829               if (is_slow_path)
 830                 {
 831                   /* Try to match static mapping by external address and port,
 832                      destination address and port in packet */
 833                   e_key0.addr = ip0->dst_address;
 834                   e_key0.port = udp0->dst_port;
 835                   e_key0.protocol = proto0;
 836                   e_key0.fib_index = rx_fib_index0;
 837                   if (snat_static_mapping_match (sm, e_key0, &l_key0, 1, 0,
 838                                                  &twice_nat0, &lb_nat0,
 839                                                  &ip0->src_address,
 840                                                  &identity_nat0))
 841                     {
 842                       /*
 843                        * Send DHCP packets to the ipv4 stack, or we won't
 844                        * be able to use dhcp client on the outside interface
 845                        */
 846                       if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_UDP
 847                                          && (udp0->dst_port ==
 848                                              clib_host_to_net_u16
 849                                              (UDP_DST_PORT_dhcp_to_client))))
 850                         {
 851                           vnet_feature_next (&next0, b0);
 852                           goto trace00;
 853                         }
 854
 855                       if (!sm->forwarding_enabled)
 856                         {
 857                           b0->error =
 858                             node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
 859                           next0 = NAT44_ED_OUT2IN_NEXT_DROP;
 860                         }
 861                       else
 862                         {
 863                           if (next_src_nat (sm, ip0, ip0->protocol,
 864                                             udp0->src_port, udp0->dst_port,
 865                                             thread_index, rx_fib_index0))
 866                             {
 867                               next0 = NAT44_ED_OUT2IN_NEXT_IN2OUT;
 868                               goto trace00;
 869                             }
 870                           create_bypass_for_fwd (sm, ip0, rx_fib_index0,
 871                                                  thread_index);
 872                         }
 873                       goto trace00;
 874                     }
 875
 876                   if (PREDICT_FALSE (identity_nat0))
 877                     goto trace00;
 878
 879                   if ((proto0 == SNAT_PROTOCOL_TCP) && !tcp_is_init (tcp0))
 880                     {
 881                       b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
 882                       next0 = NAT44_ED_OUT2IN_NEXT_DROP;
 883                       goto trace00;
 884                     }
 885
 886                   /* Create session initiated by host from external network */
 887                   s0 = create_session_for_static_mapping_ed (sm, b0, l_key0,
 888                                                              e_key0, node,
 889                                                              thread_index,
 890                                                              twice_nat0,
 891                                                              lb_nat0, now);
 892
 893                   if (!s0)
 894                     {
 895                       next0 = NAT44_ED_OUT2IN_NEXT_DROP;
 896                       goto trace00;
 897                     }
 898                 }
 899               else
 900                 {
 901                   next0 = NAT44_ED_OUT2IN_NEXT_SLOW_PATH;
 902                   goto trace00;
 903                 }
 904             }
 905           else
 906             {
 907               s0 = pool_elt_at_index (tsm->sessions, value0.value);
 908             }
 909
 910           old_addr0 = ip0->dst_address.as_u32;
 911           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
 912           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
 913
 914           sum0 = ip0->checksum;
 915           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 916                                  dst_address);
 917           if (PREDICT_FALSE (is_twice_nat_session (s0)))
 918             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 919                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
 920                                    src_address);
 921           ip0->checksum = ip_csum_fold (sum0);
 922
 923           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
 924             {
 925               old_port0 = tcp0->dst_port;
 926               new_port0 = tcp0->dst_port = s0->in2out.port;
 927
 928               sum0 = tcp0->checksum;
 929               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 930                                      dst_address);
 931               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 932                                      length);
 933               if (is_twice_nat_session (s0))
 934                 {
 935                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
 936                                          s0->ext_host_nat_addr.as_u32,
 937                                          ip4_header_t, dst_address);
 938                   sum0 = ip_csum_update (sum0, tcp0->src_port,
 939                                          s0->ext_host_nat_port, ip4_header_t,
 940                                          length);
 941                   tcp0->src_port = s0->ext_host_nat_port;
 942                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 943                 }
 944               tcp0->checksum = ip_csum_fold (sum0);
 945               if (nat44_set_tcp_session_state_o2i
 946                   (sm, s0, tcp0, thread_index))
 947                 goto trace00;
 948             }
 949           else
 950             {
 951               udp0->dst_port = s0->in2out.port;
 952               if (is_twice_nat_session (s0))
 953                 {
 954                   udp0->src_port = s0->ext_host_nat_port;
 955                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
 956                 }
 957               udp0->checksum = 0;
 958             }
 959
 960           /* Accounting */
 961           nat44_session_update_counters (s0, now,
 962                                          vlib_buffer_length_in_chain (vm,
 963                                                                       b0));
 964           /* Per-user LRU list maintenance */
 965           nat44_session_update_lru (sm, s0, thread_index);
 966
 967         trace00:
 968           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 969                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 970             {
 971               nat44_ed_out2in_trace_t *t =
 972                 vlib_add_trace (vm, node, b0, sizeof (*t));
 973               t->is_slow_path = is_slow_path;
 974               t->sw_if_index = sw_if_index0;
 975               t->next_index = next0;
 976               t->session_index = ~0;
 977               if (s0)
 978                 t->session_index = s0 - tsm->sessions;
 979             }
 980
 981           pkts_processed += next0 != NAT44_ED_OUT2IN_NEXT_DROP;
 982
 983           next1 = NAT44_ED_OUT2IN_NEXT_LOOKUP;
 984           vnet_buffer (b1)->snat.flags = 0;
 985           ip1 = vlib_buffer_get_current (b1);
 986
 987           sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];
 988           rx_fib_index1 =
 989             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 990                                                  sw_if_index1);
 991
 992           if (PREDICT_FALSE (ip1->ttl == 1))
 993             {
 994               vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 995               icmp4_error_set_vnet_buffer (b1, ICMP4_time_exceeded,
 996                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 997                                            0);
 998               next1 = NAT44_ED_OUT2IN_NEXT_ICMP_ERROR;
 999               goto trace01;
1000             }
1001
1002           udp1 = ip4_next_header (ip1);
1003           tcp1 = (tcp_header_t *) udp1;
1004           icmp1 = (icmp46_header_t *) udp1;
1005           proto1 = ip_proto_to_snat_proto (ip1->protocol);
1006
1007           if (is_slow_path)
1008             {
1009               if (PREDICT_FALSE (proto1 == ~0))
1010                 {
1011                   s1 =
1012                     nat44_ed_out2in_unknown_proto (sm, b1, ip1, rx_fib_index1,
1013                                                    thread_index, now, vm,
1014                                                    node);
1015                   if (!sm->forwarding_enabled)
1016                     {
1017                       if (!s1)
1018                         next1 = NAT44_ED_OUT2IN_NEXT_DROP;
1019                       goto trace01;
1020                     }
1021                 }
1022
1023               if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP))
1024                 {
1025                   next1 = icmp_out2in_ed_slow_path
1026                     (sm, b1, ip1, icmp1, sw_if_index1, rx_fib_index1, node,
1027                      next1, now, thread_index, &s1);
1028                   goto trace01;
1029                 }
1030             }
1031           else
1032             {
1033               if (PREDICT_FALSE (proto1 == ~0))
1034                 {
1035                   next1 = NAT44_ED_OUT2IN_NEXT_SLOW_PATH;
1036                   goto trace01;
1037                 }
1038
1039               if (ip4_is_fragment (ip1))
1040                 {
1041                   next1 = NAT44_ED_OUT2IN_NEXT_REASS;
1042                   goto trace01;
1043                 }
1044
1045               if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP))
1046                 {
1047                   next1 = NAT44_ED_OUT2IN_NEXT_SLOW_PATH;
1048                   goto trace01;
1049                 }
1050             }
1051
1052           make_ed_kv (&kv1, &ip1->dst_address, &ip1->src_address,
1053                       ip1->protocol, rx_fib_index1, udp1->dst_port,
1054                       udp1->src_port);
1055
1056           if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv1, &value1))
1057             {
1058               if (is_slow_path)
1059                 {
1060                   /* Try to match static mapping by external address and port,
1061                      destination address and port in packet */
1062                   e_key1.addr = ip1->dst_address;
1063                   e_key1.port = udp1->dst_port;
1064                   e_key1.protocol = proto1;
1065                   e_key1.fib_index = rx_fib_index1;
1066                   if (snat_static_mapping_match (sm, e_key1, &l_key1, 1, 0,
1067                                                  &twice_nat1, &lb_nat1,
1068                                                  &ip1->src_address,
1069                                                  &identity_nat1))
1070                     {
1071                       /*
1072                        * Send DHCP packets to the ipv4 stack, or we won't
1073                        * be able to use dhcp client on the outside interface
1074                        */
1075                       if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_UDP
1076                                          && (udp1->dst_port ==
1077                                              clib_host_to_net_u16
1078                                              (UDP_DST_PORT_dhcp_to_client))))
1079                         {
1080                           vnet_feature_next (&next1, b1);
1081                           goto trace01;
1082                         }
1083
1084                       if (!sm->forwarding_enabled)
1085                         {
1086                           b1->error =
1087                             node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
1088                           next1 = NAT44_ED_OUT2IN_NEXT_DROP;
1089                         }
1090                       else
1091                         {
1092                           if (next_src_nat (sm, ip1, ip1->protocol,
1093                                             udp1->src_port, udp1->dst_port,
1094                                             thread_index, rx_fib_index1))
1095                             {
1096                               next1 = NAT44_ED_OUT2IN_NEXT_IN2OUT;
1097                               goto trace01;
1098                             }
1099                           create_bypass_for_fwd (sm, ip1, rx_fib_index1,
1100                                                  thread_index);
1101                         }
1102                       goto trace01;
1103                     }
1104
1105                   if (PREDICT_FALSE (identity_nat1))
1106                     goto trace01;
1107
1108                   if ((proto1 == SNAT_PROTOCOL_TCP) && !tcp_is_init (tcp1))
1109                     {
1110                       b1->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
1111                       next1 = NAT44_ED_OUT2IN_NEXT_DROP;
1112                       goto trace01;
1113                     }
1114
1115                   /* Create session initiated by host from external network */
1116                   s1 = create_session_for_static_mapping_ed (sm, b1, l_key1,
1117                                                              e_key1, node,
1118                                                              thread_index,
1119                                                              twice_nat1,
1120                                                              lb_nat1, now);
1121
1122                   if (!s1)
1123                     {
1124                       next1 = NAT44_ED_OUT2IN_NEXT_DROP;
1125                       goto trace01;
1126                     }
1127                 }
1128               else
1129                 {
1130                   next1 = NAT44_ED_OUT2IN_NEXT_SLOW_PATH;
1131                   goto trace01;
1132                 }
1133             }
1134           else
1135             {
1136               s1 = pool_elt_at_index (tsm->sessions, value1.value);
1137             }
1138
1139           old_addr1 = ip1->dst_address.as_u32;
1140           new_addr1 = ip1->dst_address.as_u32 = s1->in2out.addr.as_u32;
1141           vnet_buffer (b1)->sw_if_index[VLIB_TX] = s1->in2out.fib_index;
1142
1143           sum1 = ip1->checksum;
1144           sum1 = ip_csum_update (sum1, old_addr1, new_addr1, ip4_header_t,
1145                                  dst_address);
1146           if (PREDICT_FALSE (is_twice_nat_session (s1)))
1147             sum1 = ip_csum_update (sum1, ip1->src_address.as_u32,
1148                                    s1->ext_host_nat_addr.as_u32, ip4_header_t,
1149                                    src_address);
1150           ip1->checksum = ip_csum_fold (sum1);
1151
1152           if (PREDICT_TRUE (proto1 == SNAT_PROTOCOL_TCP))
1153             {
1154               old_port1 = tcp1->dst_port;
1155               new_port1 = tcp1->dst_port = s1->in2out.port;
1156
1157               sum1 = tcp1->checksum;
1158               sum1 = ip_csum_update (sum1, old_addr1, new_addr1, ip4_header_t,
1159                                      dst_address);
1160               sum1 = ip_csum_update (sum1, old_port1, new_port1, ip4_header_t,
1161                                      length);
1162               if (is_twice_nat_session (s1))
1163                 {
1164                   sum1 = ip_csum_update (sum1, ip1->src_address.as_u32,
1165                                          s1->ext_host_nat_addr.as_u32,
1166                                          ip4_header_t, dst_address);
1167                   sum1 = ip_csum_update (sum1, tcp1->src_port,
1168                                          s1->ext_host_nat_port, ip4_header_t,
1169                                          length);
1170                   tcp1->src_port = s1->ext_host_nat_port;
1171                   ip1->src_address.as_u32 = s1->ext_host_nat_addr.as_u32;
1172                 }
1173               tcp1->checksum = ip_csum_fold (sum1);
1174               if (nat44_set_tcp_session_state_o2i
1175                   (sm, s1, tcp1, thread_index))
1176                 goto trace01;
1177             }
1178           else
1179             {
1180               udp1->dst_port = s1->in2out.port;
1181               if (is_twice_nat_session (s1))
1182                 {
1183                   udp1->src_port = s1->ext_host_nat_port;
1184                   ip1->src_address.as_u32 = s1->ext_host_nat_addr.as_u32;
1185                 }
1186               udp1->checksum = 0;
1187             }
1188
1189           /* Accounting */
1190           nat44_session_update_counters (s1, now,
1191                                          vlib_buffer_length_in_chain (vm,
1192                                                                       b1));
1193           /* Per-user LRU list maintenance */
1194           nat44_session_update_lru (sm, s1, thread_index);
1195
1196         trace01:
1197           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1198                              && (b1->flags & VLIB_BUFFER_IS_TRACED)))
1199             {
1200               nat44_ed_out2in_trace_t *t =
1201                 vlib_add_trace (vm, node, b1, sizeof (*t));
1202               t->is_slow_path = is_slow_path;
1203               t->sw_if_index = sw_if_index1;
1204               t->next_index = next1;
1205               t->session_index = ~0;
1206               if (s1)
1207                 t->session_index = s1 - tsm->sessions;
1208             }
1209
1210           pkts_processed += next1 != NAT44_ED_OUT2IN_NEXT_DROP;
1211
1212           /* verify speculative enqueues, maybe switch current next frame */
1213           vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
1214                                            to_next, n_left_to_next,
1215                                            bi0, bi1, next0, next1);
1216         }
1217
1218       while (n_left_from > 0 && n_left_to_next > 0)
1219         {
1220           u32 bi0;
1221           vlib_buffer_t *b0;
1222           u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
1223             new_addr0;
1224           u16 old_port0, new_port0;
1225           ip4_header_t *ip0;
1226           udp_header_t *udp0;
1227           tcp_header_t *tcp0;
1228           icmp46_header_t *icmp0;
1229           snat_session_t *s0 = 0;
1230           clib_bihash_kv_16_8_t kv0, value0;
1231           ip_csum_t sum0;
1232           snat_session_key_t e_key0, l_key0;
1233           lb_nat_type_t lb_nat0;
1234           twice_nat_type_t twice_nat0;
1235           u8 identity_nat0;
1236
1237           /* speculatively enqueue b0 to the current next frame */
1238           bi0 = from[0];
1239           to_next[0] = bi0;
1240           from += 1;
1241           to_next += 1;
1242           n_left_from -= 1;
1243           n_left_to_next -= 1;
1244
1245           b0 = vlib_get_buffer (vm, bi0);
1246           next0 = NAT44_ED_OUT2IN_NEXT_LOOKUP;
1247           vnet_buffer (b0)->snat.flags = 0;
1248           ip0 = vlib_buffer_get_current (b0);
1249
1250           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1251           rx_fib_index0 =
1252             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
1253                                                  sw_if_index0);
1254
1255           if (PREDICT_FALSE (ip0->ttl == 1))
1256             {
1257               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1258               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1259                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1260                                            0);
1261               next0 = NAT44_ED_OUT2IN_NEXT_ICMP_ERROR;
1262               goto trace0;
1263             }
1264
1265           udp0 = ip4_next_header (ip0);
1266           tcp0 = (tcp_header_t *) udp0;
1267           icmp0 = (icmp46_header_t *) udp0;
1268           proto0 = ip_proto_to_snat_proto (ip0->protocol);
1269
1270           if (is_slow_path)
1271             {
1272               if (PREDICT_FALSE (proto0 == ~0))
1273                 {
1274                   s0 =
1275                     nat44_ed_out2in_unknown_proto (sm, b0, ip0, rx_fib_index0,
1276                                                    thread_index, now, vm,
1277                                                    node);
1278                   if (!sm->forwarding_enabled)
1279                     {
1280                       if (!s0)
1281                         next0 = NAT44_ED_OUT2IN_NEXT_DROP;
1282                       goto trace0;
1283                     }
1284                 }
1285
1286               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1287                 {
1288                   next0 = icmp_out2in_ed_slow_path
1289                     (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1290                      next0, now, thread_index, &s0);
1291                   goto trace0;
1292                 }
1293             }
1294           else
1295             {
1296               if (PREDICT_FALSE (proto0 == ~0))
1297                 {
1298                   next0 = NAT44_ED_OUT2IN_NEXT_SLOW_PATH;
1299                   goto trace0;
1300                 }
1301
1302               if (ip4_is_fragment (ip0))
1303                 {
1304                   next0 = NAT44_ED_OUT2IN_NEXT_REASS;
1305                   goto trace0;
1306                 }
1307
1308               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1309                 {
1310                   next0 = NAT44_ED_OUT2IN_NEXT_SLOW_PATH;
1311                   goto trace0;
1312                 }
1313             }
1314
1315           make_ed_kv (&kv0, &ip0->dst_address, &ip0->src_address,
1316                       ip0->protocol, rx_fib_index0, udp0->dst_port,
1317                       udp0->src_port);
1318
1319           if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv0, &value0))
1320             {
1321               if (is_slow_path)
1322                 {
1323                   /* Try to match static mapping by external address and port,
1324                      destination address and port in packet */
1325                   e_key0.addr = ip0->dst_address;
1326                   e_key0.port = udp0->dst_port;
1327                   e_key0.protocol = proto0;
1328                   e_key0.fib_index = rx_fib_index0;
1329                   if (snat_static_mapping_match (sm, e_key0, &l_key0, 1, 0,
1330                                                  &twice_nat0, &lb_nat0,
1331                                                  &ip0->src_address,
1332                                                  &identity_nat0))
1333                     {
1334                       /*
1335                        * Send DHCP packets to the ipv4 stack, or we won't
1336                        * be able to use dhcp client on the outside interface
1337                        */
1338                       if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_UDP
1339                                          && (udp0->dst_port ==
1340                                              clib_host_to_net_u16
1341                                              (UDP_DST_PORT_dhcp_to_client))))
1342                         {
1343                           vnet_feature_next (&next0, b0);
1344                           goto trace0;
1345                         }
1346
1347                       if (!sm->forwarding_enabled)
1348                         {
1349                           b0->error =
1350                             node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
1351                           next0 = NAT44_ED_OUT2IN_NEXT_DROP;
1352                         }
1353                       else
1354                         {
1355                           if (next_src_nat (sm, ip0, ip0->protocol,
1356                                             udp0->src_port, udp0->dst_port,
1357                                             thread_index, rx_fib_index0))
1358                             {
1359                               next0 = NAT44_ED_OUT2IN_NEXT_IN2OUT;
1360                               goto trace0;
1361                             }
1362                           create_bypass_for_fwd (sm, ip0, rx_fib_index0,
1363                                                  thread_index);
1364                         }
1365                       goto trace0;
1366                     }
1367
1368                   if (PREDICT_FALSE (identity_nat0))
1369                     goto trace0;
1370
1371                   if ((proto0 == SNAT_PROTOCOL_TCP) && !tcp_is_init (tcp0))
1372                     {
1373                       b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
1374                       next0 = NAT44_ED_OUT2IN_NEXT_DROP;
1375                       goto trace0;
1376                     }
1377
1378                   /* Create session initiated by host from external network */
1379                   s0 = create_session_for_static_mapping_ed (sm, b0, l_key0,
1380                                                              e_key0, node,
1381                                                              thread_index,
1382                                                              twice_nat0,
1383                                                              lb_nat0, now);
1384
1385                   if (!s0)
1386                     {
1387                       next0 = NAT44_ED_OUT2IN_NEXT_DROP;
1388                       goto trace0;
1389                     }
1390                 }
1391               else
1392                 {
1393                   next0 = NAT44_ED_OUT2IN_NEXT_SLOW_PATH;
1394                   goto trace0;
1395                 }
1396             }
1397           else
1398             {
1399               s0 = pool_elt_at_index (tsm->sessions, value0.value);
1400             }
1401
1402           old_addr0 = ip0->dst_address.as_u32;
1403           new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.as_u32;
1404           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
1405
1406           sum0 = ip0->checksum;
1407           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1408                                  dst_address);
1409           if (PREDICT_FALSE (is_twice_nat_session (s0)))
1410             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1411                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
1412                                    src_address);
1413           ip0->checksum = ip_csum_fold (sum0);
1414
1415           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
1416             {
1417               old_port0 = tcp0->dst_port;
1418               new_port0 = tcp0->dst_port = s0->in2out.port;
1419
1420               sum0 = tcp0->checksum;
1421               sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
1422                                      dst_address);
1423               sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
1424                                      length);
1425               if (is_twice_nat_session (s0))
1426                 {
1427                   sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1428                                          s0->ext_host_nat_addr.as_u32,
1429                                          ip4_header_t, dst_address);
1430                   sum0 = ip_csum_update (sum0, tcp0->src_port,
1431                                          s0->ext_host_nat_port, ip4_header_t,
1432                                          length);
1433                   tcp0->src_port = s0->ext_host_nat_port;
1434                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1435                 }
1436               tcp0->checksum = ip_csum_fold (sum0);
1437               if (nat44_set_tcp_session_state_o2i
1438                   (sm, s0, tcp0, thread_index))
1439                 goto trace0;
1440             }
1441           else
1442             {
1443               udp0->dst_port = s0->in2out.port;
1444               if (is_twice_nat_session (s0))
1445                 {
1446                   udp0->src_port = s0->ext_host_nat_port;
1447                   ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1448                 }
1449               udp0->checksum = 0;
1450             }
1451
1452           /* Accounting */
1453           nat44_session_update_counters (s0, now,
1454                                          vlib_buffer_length_in_chain (vm,
1455                                                                       b0));
1456           /* Per-user LRU list maintenance */
1457           nat44_session_update_lru (sm, s0, thread_index);
1458
1459         trace0:
1460           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1461                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1462             {
1463               nat44_ed_out2in_trace_t *t =
1464                 vlib_add_trace (vm, node, b0, sizeof (*t));
1465               t->is_slow_path = is_slow_path;
1466               t->sw_if_index = sw_if_index0;
1467               t->next_index = next0;
1468               t->session_index = ~0;
1469               if (s0)
1470                 t->session_index = s0 - tsm->sessions;
1471             }
1472
1473           pkts_processed += next0 != NAT44_ED_OUT2IN_NEXT_DROP;
1474           /* verify speculative enqueue, maybe switch current next frame */
1475           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1476                                            to_next, n_left_to_next,
1477                                            bi0, next0);
1478         }
1479
1480       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1481     }
1482
1483   vlib_node_increment_counter (vm, stats_node_index,
1484                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
1485                                pkts_processed);
1486   return frame->n_vectors;
1487 }
1488
1489 static uword
1490 nat44_ed_out2in_fast_path_fn (vlib_main_t * vm,
1491                               vlib_node_runtime_t * node,
1492                               vlib_frame_t * frame)
1493 {
1494   return nat44_ed_out2in_node_fn_inline (vm, node, frame, 0);
1495 }
1496
1497 /* *INDENT-OFF* */
1498 VLIB_REGISTER_NODE (nat44_ed_out2in_node) = {
1499   .function = nat44_ed_out2in_fast_path_fn,
1500   .name = "nat44-ed-out2in",
1501   .vector_size = sizeof (u32),
1502   .format_trace = format_nat44_ed_out2in_trace,
1503   .type = VLIB_NODE_TYPE_INTERNAL,
1504   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1505   .error_strings = nat_out2in_ed_error_strings,
1506   .runtime_data_bytes = sizeof (snat_runtime_t),
1507   .n_next_nodes = NAT44_ED_OUT2IN_N_NEXT,
1508   .next_nodes = {
1509     [NAT44_ED_OUT2IN_NEXT_DROP] = "error-drop",
1510     [NAT44_ED_OUT2IN_NEXT_LOOKUP] = "ip4-lookup",
1511     [NAT44_ED_OUT2IN_NEXT_SLOW_PATH] = "nat44-ed-out2in-slowpath",
1512     [NAT44_ED_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1513     [NAT44_ED_OUT2IN_NEXT_IN2OUT] = "nat44-ed-in2out",
1514     [NAT44_ED_OUT2IN_NEXT_REASS] = "nat44-ed-out2in-reass",
1515   },
1516 };
1517 /* *INDENT-ON* */
1518
1519 VLIB_NODE_FUNCTION_MULTIARCH (nat44_ed_out2in_node,
1520                               nat44_ed_out2in_fast_path_fn);
1521
1522 static uword
1523 nat44_ed_out2in_slow_path_fn (vlib_main_t * vm,
1524                               vlib_node_runtime_t * node,
1525                               vlib_frame_t * frame)
1526 {
1527   return nat44_ed_out2in_node_fn_inline (vm, node, frame, 1);
1528 }
1529
1530 /* *INDENT-OFF* */
1531 VLIB_REGISTER_NODE (nat44_ed_out2in_slowpath_node) = {
1532   .function = nat44_ed_out2in_slow_path_fn,
1533   .name = "nat44-ed-out2in-slowpath",
1534   .vector_size = sizeof (u32),
1535   .format_trace = format_nat44_ed_out2in_trace,
1536   .type = VLIB_NODE_TYPE_INTERNAL,
1537   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1538   .error_strings = nat_out2in_ed_error_strings,
1539   .runtime_data_bytes = sizeof (snat_runtime_t),
1540   .n_next_nodes = NAT44_ED_OUT2IN_N_NEXT,
1541   .next_nodes = {
1542     [NAT44_ED_OUT2IN_NEXT_DROP] = "error-drop",
1543     [NAT44_ED_OUT2IN_NEXT_LOOKUP] = "ip4-lookup",
1544     [NAT44_ED_OUT2IN_NEXT_SLOW_PATH] = "nat44-ed-out2in-slowpath",
1545     [NAT44_ED_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1546     [NAT44_ED_OUT2IN_NEXT_IN2OUT] = "nat44-ed-in2out",
1547     [NAT44_ED_OUT2IN_NEXT_REASS] = "nat44-ed-out2in-reass",
1548   },
1549 };
1550 /* *INDENT-ON* */
1551
1552 VLIB_NODE_FUNCTION_MULTIARCH (nat44_ed_out2in_slowpath_node,
1553                               nat44_ed_out2in_slow_path_fn);
1554
1555 static uword
1556 nat44_ed_out2in_reass_node_fn (vlib_main_t * vm,
1557                                vlib_node_runtime_t * node,
1558                                vlib_frame_t * frame)
1559 {
1560   u32 n_left_from, *from, *to_next;
1561   nat44_ed_out2in_next_t next_index;
1562   u32 pkts_processed = 0;
1563   snat_main_t *sm = &snat_main;
1564   f64 now = vlib_time_now (vm);
1565   u32 thread_index = vm->thread_index;
1566   snat_main_per_thread_data_t *per_thread_data =
1567     &sm->per_thread_data[thread_index];
1568   u32 *fragments_to_drop = 0;
1569   u32 *fragments_to_loopback = 0;
1570
1571   from = vlib_frame_vector_args (frame);
1572   n_left_from = frame->n_vectors;
1573   next_index = node->cached_next_index;
1574
1575   while (n_left_from > 0)
1576     {
1577       u32 n_left_to_next;
1578
1579       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1580
1581       while (n_left_from > 0 && n_left_to_next > 0)
1582         {
1583           u32 bi0, sw_if_index0, proto0, rx_fib_index0, new_addr0, old_addr0;
1584           vlib_buffer_t *b0;
1585           u32 next0;
1586           u8 cached0 = 0;
1587           ip4_header_t *ip0;
1588           nat_reass_ip4_t *reass0;
1589           udp_header_t *udp0;
1590           tcp_header_t *tcp0;
1591           icmp46_header_t *icmp0;
1592           clib_bihash_kv_16_8_t kv0, value0;
1593           snat_session_t *s0 = 0;
1594           u16 old_port0, new_port0;
1595           ip_csum_t sum0;
1596           snat_session_key_t e_key0, l_key0;
1597           lb_nat_type_t lb0;
1598           twice_nat_type_t twice_nat0;
1599           u8 identity_nat0;
1600
1601           /* speculatively enqueue b0 to the current next frame */
1602           bi0 = from[0];
1603           to_next[0] = bi0;
1604           from += 1;
1605           to_next += 1;
1606           n_left_from -= 1;
1607           n_left_to_next -= 1;
1608
1609           b0 = vlib_get_buffer (vm, bi0);
1610           next0 = NAT44_ED_OUT2IN_NEXT_LOOKUP;
1611
1612           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1613           rx_fib_index0 =
1614             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
1615                                                  sw_if_index0);
1616
1617           if (PREDICT_FALSE (nat_reass_is_drop_frag (0)))
1618             {
1619               next0 = NAT44_ED_OUT2IN_NEXT_DROP;
1620               b0->error = node->errors[NAT_OUT2IN_ED_ERROR_DROP_FRAGMENT];
1621               goto trace0;
1622             }
1623
1624           ip0 = (ip4_header_t *) vlib_buffer_get_current (b0);
1625           udp0 = ip4_next_header (ip0);
1626           tcp0 = (tcp_header_t *) udp0;
1627           icmp0 = (icmp46_header_t *) udp0;
1628           proto0 = ip_proto_to_snat_proto (ip0->protocol);
1629
1630           reass0 = nat_ip4_reass_find_or_create (ip0->src_address,
1631                                                  ip0->dst_address,
1632                                                  ip0->fragment_id,
1633                                                  ip0->protocol,
1634                                                  1, &fragments_to_drop);
1635
1636           if (PREDICT_FALSE (!reass0))
1637             {
1638               next0 = NAT44_ED_OUT2IN_NEXT_DROP;
1639               b0->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_REASS];
1640               nat_log_notice ("maximum reassemblies exceeded");
1641               goto trace0;
1642             }
1643
1644           if (PREDICT_FALSE (ip4_is_first_fragment (ip0)))
1645             {
1646               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1647                 {
1648                   next0 = icmp_out2in_ed_slow_path
1649                     (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1650                      next0, now, thread_index, &s0);
1651
1652                   if (PREDICT_TRUE (next0 != NAT44_ED_OUT2IN_NEXT_DROP))
1653                     {
1654                       if (s0)
1655                         reass0->sess_index = s0 - per_thread_data->sessions;
1656                       else
1657                         reass0->flags |= NAT_REASS_FLAG_ED_DONT_TRANSLATE;
1658                       reass0->thread_index = thread_index;
1659                       nat_ip4_reass_get_frags (reass0,
1660                                                &fragments_to_loopback);
1661                     }
1662
1663                   goto trace0;
1664                 }
1665
1666               make_ed_kv (&kv0, &ip0->dst_address, &ip0->src_address,
1667                           ip0->protocol, rx_fib_index0, udp0->dst_port,
1668                           udp0->src_port);
1669
1670               if (clib_bihash_search_16_8
1671                   (&per_thread_data->out2in_ed, &kv0, &value0))
1672                 {
1673                   /* Try to match static mapping by external address and port,
1674                      destination address and port in packet */
1675                   e_key0.addr = ip0->dst_address;
1676                   e_key0.port = udp0->dst_port;
1677                   e_key0.protocol = proto0;
1678                   e_key0.fib_index = rx_fib_index0;
1679                   if (snat_static_mapping_match (sm, e_key0, &l_key0, 1, 0,
1680                                                  &twice_nat0, &lb0, 0,
1681                                                  &identity_nat0))
1682                     {
1683                       /*
1684                        * Send DHCP packets to the ipv4 stack, or we won't
1685                        * be able to use dhcp client on the outside interface
1686                        */
1687                       if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_UDP
1688                                          && (udp0->dst_port
1689                                              ==
1690                                              clib_host_to_net_u16
1691                                              (UDP_DST_PORT_dhcp_to_client))))
1692                         {
1693                           vnet_feature_next (&next0, b0);
1694                           goto trace0;
1695                         }
1696
1697                       if (!sm->forwarding_enabled)
1698                         {
1699                           b0->error =
1700                             node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
1701                           next0 = NAT44_ED_OUT2IN_NEXT_DROP;
1702                         }
1703                       else
1704                         {
1705                           if (next_src_nat (sm, ip0, ip0->protocol,
1706                                             udp0->src_port, udp0->dst_port,
1707                                             thread_index, rx_fib_index0))
1708                             {
1709                               next0 = NAT44_ED_OUT2IN_NEXT_IN2OUT;
1710                               goto trace0;
1711                             }
1712                           create_bypass_for_fwd (sm, ip0, rx_fib_index0,
1713                                                  thread_index);
1714                           reass0->flags |= NAT_REASS_FLAG_ED_DONT_TRANSLATE;
1715                           nat_ip4_reass_get_frags (reass0,
1716                                                    &fragments_to_loopback);
1717                         }
1718                       goto trace0;
1719                     }
1720
1721                   if (PREDICT_FALSE (identity_nat0))
1722                     {
1723                       reass0->flags |= NAT_REASS_FLAG_ED_DONT_TRANSLATE;
1724                       goto trace0;
1725                     }
1726
1727                   if ((proto0 == SNAT_PROTOCOL_TCP) && !tcp_is_init (tcp0))
1728                     {
1729                       b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
1730                       next0 = NAT44_ED_OUT2IN_NEXT_DROP;
1731                       goto trace0;
1732                     }
1733
1734                   /* Create session initiated by host from external network */
1735                   s0 = create_session_for_static_mapping_ed (sm, b0, l_key0,
1736                                                              e_key0, node,
1737                                                              thread_index,
1738                                                              twice_nat0, lb0,
1739                                                              now);
1740                   if (!s0)
1741                     {
1742                       b0->error =
1743                         node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
1744                       next0 = NAT44_ED_OUT2IN_NEXT_DROP;
1745                       goto trace0;
1746                     }
1747                   reass0->sess_index = s0 - per_thread_data->sessions;
1748                   reass0->thread_index = thread_index;
1749                 }
1750               else
1751                 {
1752                   s0 = pool_elt_at_index (per_thread_data->sessions,
1753                                           value0.value);
1754                   reass0->sess_index = value0.value;
1755                 }
1756               nat_ip4_reass_get_frags (reass0, &fragments_to_loopback);
1757             }
1758           else
1759             {
1760               if (reass0->flags & NAT_REASS_FLAG_ED_DONT_TRANSLATE)
1761                 goto trace0;
1762               if (PREDICT_FALSE (reass0->sess_index == (u32) ~ 0))
1763                 {
1764                   if (nat_ip4_reass_add_fragment
1765                       (reass0, bi0, &fragments_to_drop))
1766                     {
1767                       b0->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_FRAG];
1768                       nat_log_notice
1769                         ("maximum fragments per reassembly exceeded");
1770                       next0 = NAT44_ED_OUT2IN_NEXT_DROP;
1771                       goto trace0;
1772                     }
1773                   cached0 = 1;
1774                   goto trace0;
1775                 }
1776               s0 = pool_elt_at_index (per_thread_data->sessions,
1777                                       reass0->sess_index);
1778             }
1779
1780           old_addr0 = ip0->dst_address.as_u32;
1781           ip0->dst_address = s0->in2out.addr;
1782           new_addr0 = ip0->dst_address.as_u32;
1783           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
1784
1785           sum0 = ip0->checksum;
1786           sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1787                                  ip4_header_t,
1788                                  dst_address /* changed member */ );
1789           if (PREDICT_FALSE (is_twice_nat_session (s0)))
1790             sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1791                                    s0->ext_host_nat_addr.as_u32, ip4_header_t,
1792                                    src_address);
1793           ip0->checksum = ip_csum_fold (sum0);
1794
1795           if (PREDICT_FALSE (ip4_is_first_fragment (ip0)))
1796             {
1797               if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
1798                 {
1799                   old_port0 = tcp0->dst_port;
1800                   tcp0->dst_port = s0->in2out.port;
1801                   new_port0 = tcp0->dst_port;
1802
1803                   sum0 = tcp0->checksum;
1804                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1805                                          ip4_header_t,
1806                                          dst_address /* changed member */ );
1807
1808                   sum0 = ip_csum_update (sum0, old_port0, new_port0,
1809                                          ip4_header_t /* cheat */ ,
1810                                          length /* changed member */ );
1811                   if (is_twice_nat_session (s0))
1812                     {
1813                       sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
1814                                              s0->ext_host_nat_addr.as_u32,
1815                                              ip4_header_t, dst_address);
1816                       sum0 = ip_csum_update (sum0, tcp0->src_port,
1817                                              s0->ext_host_nat_port,
1818                                              ip4_header_t, length);
1819                       tcp0->src_port = s0->ext_host_nat_port;
1820                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1821                     }
1822                   tcp0->checksum = ip_csum_fold (sum0);
1823                 }
1824               else
1825                 {
1826                   old_port0 = udp0->dst_port;
1827                   udp0->dst_port = s0->in2out.port;
1828                   if (is_twice_nat_session (s0))
1829                     {
1830                       udp0->src_port = s0->ext_host_nat_port;
1831                       ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
1832                     }
1833                   udp0->checksum = 0;
1834                 }
1835             }
1836
1837           /* Accounting */
1838           nat44_session_update_counters (s0, now,
1839                                          vlib_buffer_length_in_chain (vm,
1840                                                                       b0));
1841           /* Per-user LRU list maintenance */
1842           nat44_session_update_lru (sm, s0, thread_index);
1843
1844         trace0:
1845           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1846                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1847             {
1848               nat44_reass_trace_t *t =
1849                 vlib_add_trace (vm, node, b0, sizeof (*t));
1850               t->cached = cached0;
1851               t->sw_if_index = sw_if_index0;
1852               t->next_index = next0;
1853             }
1854
1855           if (cached0)
1856             {
1857               n_left_to_next++;
1858               to_next--;
1859             }
1860           else
1861             {
1862               pkts_processed += next0 != NAT44_ED_OUT2IN_NEXT_DROP;
1863
1864               /* verify speculative enqueue, maybe switch current next frame */
1865               vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1866                                                to_next, n_left_to_next,
1867                                                bi0, next0);
1868             }
1869
1870           if (n_left_from == 0 && vec_len (fragments_to_loopback))
1871             {
1872               from = vlib_frame_vector_args (frame);
1873               u32 len = vec_len (fragments_to_loopback);
1874               if (len <= VLIB_FRAME_SIZE)
1875                 {
1876                   clib_memcpy_fast (from, fragments_to_loopback,
1877                                     sizeof (u32) * len);
1878                   n_left_from = len;
1879                   vec_reset_length (fragments_to_loopback);
1880                 }
1881               else
1882                 {
1883                   clib_memcpy_fast (from, fragments_to_loopback +
1884                                     (len - VLIB_FRAME_SIZE),
1885                                     sizeof (u32) * VLIB_FRAME_SIZE);
1886                   n_left_from = VLIB_FRAME_SIZE;
1887                   _vec_len (fragments_to_loopback) = len - VLIB_FRAME_SIZE;
1888                 }
1889             }
1890         }
1891
1892       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1893     }
1894
1895   vlib_node_increment_counter (vm, nat44_ed_out2in_reass_node.index,
1896                                NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
1897                                pkts_processed);
1898
1899   nat_send_all_to_node (vm, fragments_to_drop, node,
1900                         &node->errors[NAT_OUT2IN_ED_ERROR_DROP_FRAGMENT],
1901                         NAT44_ED_OUT2IN_NEXT_DROP);
1902
1903   vec_free (fragments_to_drop);
1904   vec_free (fragments_to_loopback);
1905   return frame->n_vectors;
1906 }
1907
1908 /* *INDENT-OFF* */
1909 VLIB_REGISTER_NODE (nat44_ed_out2in_reass_node) = {
1910   .function = nat44_ed_out2in_reass_node_fn,
1911   .name = "nat44-ed-out2in-reass",
1912   .vector_size = sizeof (u32),
1913   .format_trace = format_nat44_reass_trace,
1914   .type = VLIB_NODE_TYPE_INTERNAL,
1915   .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
1916   .error_strings = nat_out2in_ed_error_strings,
1917   .n_next_nodes = NAT44_ED_OUT2IN_N_NEXT,
1918   .next_nodes = {
1919     [NAT44_ED_OUT2IN_NEXT_DROP] = "error-drop",
1920     [NAT44_ED_OUT2IN_NEXT_LOOKUP] = "ip4-lookup",
1921     [NAT44_ED_OUT2IN_NEXT_SLOW_PATH] = "nat44-ed-out2in-slowpath",
1922     [NAT44_ED_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1923     [NAT44_ED_OUT2IN_NEXT_IN2OUT] = "nat44-ed-in2out",
1924     [NAT44_ED_OUT2IN_NEXT_REASS] = "nat44-ed-out2in-reass",
1925   },
1926 };
1927 /* *INDENT-ON* */
1928
1929 VLIB_NODE_FUNCTION_MULTIARCH (nat44_ed_out2in_reass_node,
1930                               nat44_ed_out2in_reass_node_fn);
1931
1932 /*
1933  * fd.io coding-style-patch-verification: ON
1934  *
1935  * Local Variables:
1936  * eval: (c-set-style "gnu")
1937  * End:
1938  */