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