src/plugins/nat/in2out.c

   1 /*
   2  * Copyright (c) 2016 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 #include <vlib/vlib.h>
  17 #include <vnet/vnet.h>
  18 #include <vnet/pg/pg.h>
  19 #include <vnet/handoff.h>
  20
  21 #include <vnet/ip/ip.h>
  22 #include <vnet/ethernet/ethernet.h>
  23 #include <vnet/fib/ip4_fib.h>
  24 #include <nat/nat.h>
  25 #include <nat/nat_ipfix_logging.h>
  26 #include <nat/nat_det.h>
  27 #include <nat/nat_reass.h>
  28
  29 #include <vppinfra/hash.h>
  30 #include <vppinfra/error.h>
  31 #include <vppinfra/elog.h>
  32
  33 typedef struct {
  34   u32 sw_if_index;
  35   u32 next_index;
  36   u32 session_index;
  37   u32 is_slow_path;
  38 } snat_in2out_trace_t;
  39
  40 typedef struct {
  41   u32 next_worker_index;
  42   u8 do_handoff;
  43 } snat_in2out_worker_handoff_trace_t;
  44
  45 /* packet trace format function */
  46 static u8 * format_snat_in2out_trace (u8 * s, va_list * args)
  47 {
  48   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  49   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  50   snat_in2out_trace_t * t = va_arg (*args, snat_in2out_trace_t *);
  51   char * tag;
  52
  53   tag = t->is_slow_path ? "NAT44_IN2OUT_SLOW_PATH" : "NAT44_IN2OUT_FAST_PATH";
  54
  55   s = format (s, "%s: sw_if_index %d, next index %d, session %d", tag,
  56               t->sw_if_index, t->next_index, t->session_index);
  57
  58   return s;
  59 }
  60
  61 static u8 * format_snat_in2out_fast_trace (u8 * s, va_list * args)
  62 {
  63   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  64   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  65   snat_in2out_trace_t * t = va_arg (*args, snat_in2out_trace_t *);
  66
  67   s = format (s, "NAT44_IN2OUT_FAST: sw_if_index %d, next index %d",
  68               t->sw_if_index, t->next_index);
  69
  70   return s;
  71 }
  72
  73 static u8 * format_snat_in2out_worker_handoff_trace (u8 * s, va_list * args)
  74 {
  75   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  76   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  77   snat_in2out_worker_handoff_trace_t * t =
  78     va_arg (*args, snat_in2out_worker_handoff_trace_t *);
  79   char * m;
  80
  81   m = t->do_handoff ? "next worker" : "same worker";
  82   s = format (s, "NAT44_IN2OUT_WORKER_HANDOFF: %s %d", m, t->next_worker_index);
  83
  84   return s;
  85 }
  86
  87 typedef struct {
  88   u32 sw_if_index;
  89   u32 next_index;
  90   u8 cached;
  91 } nat44_in2out_reass_trace_t;
  92
  93 static u8 * format_nat44_in2out_reass_trace (u8 * s, va_list * args)
  94 {
  95   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  96   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  97   nat44_in2out_reass_trace_t * t = va_arg (*args, nat44_in2out_reass_trace_t *);
  98
  99   s = format (s, "NAT44_IN2OUT_REASS: sw_if_index %d, next index %d, status %s",
 100               t->sw_if_index, t->next_index,
 101               t->cached ? "cached" : "translated");
 102
 103   return s;
 104 }
 105
 106 vlib_node_registration_t snat_in2out_node;
 107 vlib_node_registration_t snat_in2out_slowpath_node;
 108 vlib_node_registration_t snat_in2out_fast_node;
 109 vlib_node_registration_t snat_in2out_worker_handoff_node;
 110 vlib_node_registration_t snat_det_in2out_node;
 111 vlib_node_registration_t snat_in2out_output_node;
 112 vlib_node_registration_t snat_in2out_output_slowpath_node;
 113 vlib_node_registration_t snat_in2out_output_worker_handoff_node;
 114 vlib_node_registration_t snat_hairpin_dst_node;
 115 vlib_node_registration_t snat_hairpin_src_node;
 116 vlib_node_registration_t nat44_hairpinning_node;
 117 vlib_node_registration_t nat44_in2out_reass_node;
 118
 119
 120 #define foreach_snat_in2out_error                       \
 121 _(UNSUPPORTED_PROTOCOL, "Unsupported protocol")         \
 122 _(IN2OUT_PACKETS, "Good in2out packets processed")      \
 123 _(OUT_OF_PORTS, "Out of ports")                         \
 124 _(BAD_OUTSIDE_FIB, "Outside VRF ID not found")          \
 125 _(BAD_ICMP_TYPE, "unsupported ICMP type")               \
 126 _(NO_TRANSLATION, "No translation")                     \
 127 _(MAX_SESSIONS_EXCEEDED, "Maximum sessions exceeded")   \
 128 _(DROP_FRAGMENT, "Drop fragment")                       \
 129 _(MAX_REASS, "Maximum reassemblies exceeded")           \
 130 _(MAX_FRAG, "Maximum fragments per reassembly exceeded")
 131
 132 typedef enum {
 133 #define _(sym,str) SNAT_IN2OUT_ERROR_##sym,
 134   foreach_snat_in2out_error
 135 #undef _
 136   SNAT_IN2OUT_N_ERROR,
 137 } snat_in2out_error_t;
 138
 139 static char * snat_in2out_error_strings[] = {
 140 #define _(sym,string) string,
 141   foreach_snat_in2out_error
 142 #undef _
 143 };
 144
 145 typedef enum {
 146   SNAT_IN2OUT_NEXT_LOOKUP,
 147   SNAT_IN2OUT_NEXT_DROP,
 148   SNAT_IN2OUT_NEXT_ICMP_ERROR,
 149   SNAT_IN2OUT_NEXT_SLOW_PATH,
 150   SNAT_IN2OUT_NEXT_REASS,
 151   SNAT_IN2OUT_N_NEXT,
 152 } snat_in2out_next_t;
 153
 154 typedef enum {
 155   SNAT_HAIRPIN_SRC_NEXT_DROP,
 156   SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT,
 157   SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT_WH,
 158   SNAT_HAIRPIN_SRC_NEXT_INTERFACE_OUTPUT,
 159   SNAT_HAIRPIN_SRC_N_NEXT,
 160 } snat_hairpin_next_t;
 161
 162 /**
 163  * @brief Check if packet should be translated
 164  *
 165  * Packets aimed at outside interface and external address with active session
 166  * should be translated.
 167  *
 168  * @param sm            NAT main
 169  * @param rt            NAT runtime data
 170  * @param sw_if_index0  index of the inside interface
 171  * @param ip0           IPv4 header
 172  * @param proto0        NAT protocol
 173  * @param rx_fib_index0 RX FIB index
 174  *
 175  * @returns 0 if packet should be translated otherwise 1
 176  */
 177 static inline int
 178 snat_not_translate_fast (snat_main_t * sm, vlib_node_runtime_t *node,
 179                          u32 sw_if_index0, ip4_header_t * ip0, u32 proto0,
 180                          u32 rx_fib_index0)
 181 {
 182   if (sm->out2in_dpo)
 183     return 0;
 184
 185   fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
 186   fib_prefix_t pfx = {
 187     .fp_proto = FIB_PROTOCOL_IP4,
 188     .fp_len = 32,
 189     .fp_addr = {
 190         .ip4.as_u32 = ip0->dst_address.as_u32,
 191     },
 192   };
 193
 194   /* Don't NAT packet aimed at the intfc address */
 195   if (PREDICT_FALSE(is_interface_addr(sm, node, sw_if_index0,
 196                                       ip0->dst_address.as_u32)))
 197     return 1;
 198
 199   fei = fib_table_lookup (rx_fib_index0, &pfx);
 200   if (FIB_NODE_INDEX_INVALID != fei)
 201     {
 202       u32 sw_if_index = fib_entry_get_resolving_interface (fei);
 203       if (sw_if_index == ~0)
 204         {
 205           fei = fib_table_lookup (sm->outside_fib_index, &pfx);
 206           if (FIB_NODE_INDEX_INVALID != fei)
 207             sw_if_index = fib_entry_get_resolving_interface (fei);
 208         }
 209       snat_interface_t *i;
 210       pool_foreach (i, sm->interfaces,
 211       ({
 212         /* NAT packet aimed at outside interface */
 213         if ((nat_interface_is_outside(i)) && (sw_if_index == i->sw_if_index))
 214           return 0;
 215       }));
 216     }
 217
 218   return 1;
 219 }
 220
 221 static inline int
 222 snat_not_translate (snat_main_t * sm, vlib_node_runtime_t *node,
 223                     u32 sw_if_index0, ip4_header_t * ip0, u32 proto0,
 224                     u32 rx_fib_index0, u32 thread_index)
 225 {
 226   udp_header_t * udp0 = ip4_next_header (ip0);
 227   snat_session_key_t key0, sm0;
 228   clib_bihash_kv_8_8_t kv0, value0;
 229
 230   key0.addr = ip0->dst_address;
 231   key0.port = udp0->dst_port;
 232   key0.protocol = proto0;
 233   key0.fib_index = sm->outside_fib_index;
 234   kv0.key = key0.as_u64;
 235
 236   /* NAT packet aimed at external address if */
 237   /* has active sessions */
 238   if (clib_bihash_search_8_8 (&sm->per_thread_data[thread_index].out2in, &kv0,
 239                               &value0))
 240     {
 241       /* or is static mappings */
 242       if (!snat_static_mapping_match(sm, key0, &sm0, 1, 0, 0))
 243         return 0;
 244     }
 245   else
 246     return 0;
 247
 248   if (sm->forwarding_enabled)
 249     return 1;
 250
 251   return snat_not_translate_fast(sm, node, sw_if_index0, ip0, proto0,
 252                                  rx_fib_index0);
 253 }
 254
 255 static u32 slow_path (snat_main_t *sm, vlib_buffer_t *b0,
 256                       ip4_header_t * ip0,
 257                       u32 rx_fib_index0,
 258                       snat_session_key_t * key0,
 259                       snat_session_t ** sessionp,
 260                       vlib_node_runtime_t * node,
 261                       u32 next0,
 262                       u32 thread_index)
 263 {
 264   snat_user_t *u;
 265   snat_session_t *s;
 266   clib_bihash_kv_8_8_t kv0;
 267   snat_session_key_t key1;
 268   u32 address_index = ~0;
 269   u32 outside_fib_index;
 270   uword * p;
 271   udp_header_t * udp0 = ip4_next_header (ip0);
 272
 273   if (PREDICT_FALSE (maximum_sessions_exceeded(sm, thread_index)))
 274     {
 275       b0->error = node->errors[SNAT_IN2OUT_ERROR_MAX_SESSIONS_EXCEEDED];
 276       nat_ipfix_logging_max_sessions(sm->max_translations);
 277       return SNAT_IN2OUT_NEXT_DROP;
 278     }
 279
 280   p = hash_get (sm->ip4_main->fib_index_by_table_id, sm->outside_vrf_id);
 281   if (! p)
 282     {
 283       b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_OUTSIDE_FIB];
 284       return SNAT_IN2OUT_NEXT_DROP;
 285     }
 286   outside_fib_index = p[0];
 287
 288   key1.protocol = key0->protocol;
 289
 290   u = nat_user_get_or_create (sm, &ip0->src_address, rx_fib_index0,
 291                               thread_index);
 292   if (!u)
 293     {
 294       clib_warning ("create NAT user failed");
 295       return SNAT_IN2OUT_NEXT_DROP;
 296     }
 297
 298   /* First try to match static mapping by local address and port */
 299   if (snat_static_mapping_match (sm, *key0, &key1, 0, 0, 0))
 300     {
 301       /* Try to create dynamic translation */
 302       if (snat_alloc_outside_address_and_port (sm->addresses, rx_fib_index0,
 303                                                thread_index, &key1,
 304                                                &address_index,
 305                                                sm->port_per_thread,
 306                                                sm->per_thread_data[thread_index].snat_thread_index))
 307         {
 308           b0->error = node->errors[SNAT_IN2OUT_ERROR_OUT_OF_PORTS];
 309           return SNAT_IN2OUT_NEXT_DROP;
 310         }
 311       u->nsessions++;
 312     }
 313   else
 314     {
 315       u->nstaticsessions++;
 316     }
 317
 318   s = nat_session_alloc_or_recycle (sm, u, thread_index);
 319   if (!s)
 320     {
 321       clib_warning ("create NAT session failed");
 322       return SNAT_IN2OUT_NEXT_DROP;
 323     }
 324
 325   if (address_index == ~0)
 326     s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 327   s->outside_address_index = address_index;
 328   s->in2out = *key0;
 329   s->out2in = key1;
 330   s->out2in.protocol = key0->protocol;
 331   s->out2in.fib_index = outside_fib_index;
 332   s->ext_host_addr.as_u32 = ip0->dst_address.as_u32;
 333   s->ext_host_port = udp0->dst_port;
 334   *sessionp = s;
 335
 336   /* Add to translation hashes */
 337   kv0.key = s->in2out.as_u64;
 338   kv0.value = s - sm->per_thread_data[thread_index].sessions;
 339   if (clib_bihash_add_del_8_8 (&sm->per_thread_data[thread_index].in2out, &kv0,
 340                                1 /* is_add */))
 341       clib_warning ("in2out key add failed");
 342
 343   kv0.key = s->out2in.as_u64;
 344   kv0.value = s - sm->per_thread_data[thread_index].sessions;
 345
 346   if (clib_bihash_add_del_8_8 (&sm->per_thread_data[thread_index].out2in, &kv0,
 347                                1 /* is_add */))
 348       clib_warning ("out2in key add failed");
 349
 350   /* log NAT event */
 351   snat_ipfix_logging_nat44_ses_create(s->in2out.addr.as_u32,
 352                                       s->out2in.addr.as_u32,
 353                                       s->in2out.protocol,
 354                                       s->in2out.port,
 355                                       s->out2in.port,
 356                                       s->in2out.fib_index);
 357   return next0;
 358 }
 359
 360 static_always_inline
 361 snat_in2out_error_t icmp_get_key(ip4_header_t *ip0,
 362                                  snat_session_key_t *p_key0)
 363 {
 364   icmp46_header_t *icmp0;
 365   snat_session_key_t key0;
 366   icmp_echo_header_t *echo0, *inner_echo0 = 0;
 367   ip4_header_t *inner_ip0 = 0;
 368   void *l4_header = 0;
 369   icmp46_header_t *inner_icmp0;
 370
 371   icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
 372   echo0 = (icmp_echo_header_t *)(icmp0+1);
 373
 374   if (!icmp_is_error_message (icmp0))
 375     {
 376       key0.protocol = SNAT_PROTOCOL_ICMP;
 377       key0.addr = ip0->src_address;
 378       key0.port = echo0->identifier;
 379     }
 380   else
 381     {
 382       inner_ip0 = (ip4_header_t *)(echo0+1);
 383       l4_header = ip4_next_header (inner_ip0);
 384       key0.protocol = ip_proto_to_snat_proto (inner_ip0->protocol);
 385       key0.addr = inner_ip0->dst_address;
 386       switch (key0.protocol)
 387         {
 388         case SNAT_PROTOCOL_ICMP:
 389           inner_icmp0 = (icmp46_header_t*)l4_header;
 390           inner_echo0 = (icmp_echo_header_t *)(inner_icmp0+1);
 391           key0.port = inner_echo0->identifier;
 392           break;
 393         case SNAT_PROTOCOL_UDP:
 394         case SNAT_PROTOCOL_TCP:
 395           key0.port = ((tcp_udp_header_t*)l4_header)->dst_port;
 396           break;
 397         default:
 398           return SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL;
 399         }
 400     }
 401   *p_key0 = key0;
 402   return -1; /* success */
 403 }
 404
 405 static_always_inline int
 406 icmp_get_ed_key(ip4_header_t *ip0, nat_ed_ses_key_t *p_key0)
 407 {
 408   icmp46_header_t *icmp0;
 409   nat_ed_ses_key_t key0;
 410   icmp_echo_header_t *echo0, *inner_echo0 = 0;
 411   ip4_header_t *inner_ip0 = 0;
 412   void *l4_header = 0;
 413   icmp46_header_t *inner_icmp0;
 414
 415   icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
 416   echo0 = (icmp_echo_header_t *)(icmp0+1);
 417
 418   if (!icmp_is_error_message (icmp0))
 419     {
 420       key0.proto = IP_PROTOCOL_ICMP;
 421       key0.l_addr = ip0->src_address;
 422       key0.r_addr = ip0->dst_address;
 423       key0.l_port = key0.r_port = echo0->identifier;
 424     }
 425   else
 426     {
 427       inner_ip0 = (ip4_header_t *)(echo0+1);
 428       l4_header = ip4_next_header (inner_ip0);
 429       key0.proto = inner_ip0->protocol;
 430       key0.r_addr = inner_ip0->src_address;
 431       key0.l_addr = inner_ip0->dst_address;
 432       switch (ip_proto_to_snat_proto (inner_ip0->protocol))
 433         {
 434         case SNAT_PROTOCOL_ICMP:
 435           inner_icmp0 = (icmp46_header_t*)l4_header;
 436           inner_echo0 = (icmp_echo_header_t *)(inner_icmp0+1);
 437           key0.r_port = key0.l_port = inner_echo0->identifier;
 438           break;
 439         case SNAT_PROTOCOL_UDP:
 440         case SNAT_PROTOCOL_TCP:
 441           key0.l_port = ((tcp_udp_header_t*)l4_header)->dst_port;
 442           key0.r_port = ((tcp_udp_header_t*)l4_header)->src_port;
 443           break;
 444         default:
 445           return SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL;
 446         }
 447     }
 448   *p_key0 = key0;
 449   return 0;
 450 }
 451
 452 /**
 453  * Get address and port values to be used for ICMP packet translation
 454  * and create session if needed
 455  *
 456  * @param[in,out] sm             NAT main
 457  * @param[in,out] node           NAT node runtime
 458  * @param[in] thread_index       thread index
 459  * @param[in,out] b0             buffer containing packet to be translated
 460  * @param[out] p_proto           protocol used for matching
 461  * @param[out] p_value           address and port after NAT translation
 462  * @param[out] p_dont_translate  if packet should not be translated
 463  * @param d                      optional parameter
 464  * @param e                      optional parameter
 465  */
 466 u32 icmp_match_in2out_slow(snat_main_t *sm, vlib_node_runtime_t *node,
 467                            u32 thread_index, vlib_buffer_t *b0,
 468                            ip4_header_t *ip0, u8 *p_proto,
 469                            snat_session_key_t *p_value,
 470                            u8 *p_dont_translate, void *d, void *e)
 471 {
 472   icmp46_header_t *icmp0;
 473   u32 sw_if_index0;
 474   u32 rx_fib_index0;
 475   snat_session_key_t key0;
 476   snat_session_t *s0 = 0;
 477   u8 dont_translate = 0;
 478   clib_bihash_kv_8_8_t kv0, value0;
 479   u32 next0 = ~0;
 480   int err;
 481
 482   icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
 483   sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
 484   rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
 485
 486   err = icmp_get_key (ip0, &key0);
 487   if (err != -1)
 488     {
 489       b0->error = node->errors[err];
 490       next0 = SNAT_IN2OUT_NEXT_DROP;
 491       goto out;
 492     }
 493   key0.fib_index = rx_fib_index0;
 494
 495   kv0.key = key0.as_u64;
 496
 497   if (clib_bihash_search_8_8 (&sm->per_thread_data[thread_index].in2out, &kv0,
 498                               &value0))
 499     {
 500       if (PREDICT_FALSE(snat_not_translate(sm, node, sw_if_index0, ip0,
 501           IP_PROTOCOL_ICMP, rx_fib_index0, thread_index) &&
 502           vnet_buffer(b0)->sw_if_index[VLIB_TX] == ~0))
 503         {
 504           dont_translate = 1;
 505           goto out;
 506         }
 507
 508       if (PREDICT_FALSE(icmp_is_error_message (icmp0)))
 509         {
 510           b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
 511           next0 = SNAT_IN2OUT_NEXT_DROP;
 512           goto out;
 513         }
 514
 515       next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0,
 516                          &s0, node, next0, thread_index);
 517
 518       if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
 519         goto out;
 520     }
 521   else
 522     {
 523       if (PREDICT_FALSE(icmp0->type != ICMP4_echo_request &&
 524                         icmp0->type != ICMP4_echo_reply &&
 525                         !icmp_is_error_message (icmp0)))
 526         {
 527           b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
 528           next0 = SNAT_IN2OUT_NEXT_DROP;
 529           goto out;
 530         }
 531
 532       if (PREDICT_FALSE (value0.value == ~0ULL))
 533         {
 534           nat_ed_ses_key_t key;
 535           clib_bihash_kv_16_8_t s_kv, s_value;
 536
 537           key.as_u64[0] = 0;
 538           key.as_u64[1] = 0;
 539           if (icmp_get_ed_key (ip0, &key))
 540             {
 541               b0->error = node->errors[SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL];
 542               next0 = SNAT_IN2OUT_NEXT_DROP;
 543               goto out;
 544             }
 545           key.fib_index = rx_fib_index0;
 546           s_kv.key[0] = key.as_u64[0];
 547           s_kv.key[1] = key.as_u64[1];
 548           if (!clib_bihash_search_16_8 (&sm->in2out_ed, &s_kv, &s_value))
 549             s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
 550                                     s_value.value);
 551           else
 552            {
 553               next0 = SNAT_IN2OUT_NEXT_DROP;
 554               goto out;
 555            }
 556         }
 557       else
 558         s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
 559                                 value0.value);
 560     }
 561
 562 out:
 563   *p_proto = key0.protocol;
 564   if (s0)
 565     *p_value = s0->out2in;
 566   *p_dont_translate = dont_translate;
 567   if (d)
 568     *(snat_session_t**)d = s0;
 569   return next0;
 570 }
 571
 572 /**
 573  * Get address and port values to be used for ICMP packet translation
 574  *
 575  * @param[in] sm                 NAT main
 576  * @param[in,out] node           NAT node runtime
 577  * @param[in] thread_index       thread index
 578  * @param[in,out] b0             buffer containing packet to be translated
 579  * @param[out] p_proto           protocol used for matching
 580  * @param[out] p_value           address and port after NAT translation
 581  * @param[out] p_dont_translate  if packet should not be translated
 582  * @param d                      optional parameter
 583  * @param e                      optional parameter
 584  */
 585 u32 icmp_match_in2out_fast(snat_main_t *sm, vlib_node_runtime_t *node,
 586                            u32 thread_index, vlib_buffer_t *b0,
 587                            ip4_header_t *ip0, u8 *p_proto,
 588                            snat_session_key_t *p_value,
 589                            u8 *p_dont_translate, void *d, void *e)
 590 {
 591   icmp46_header_t *icmp0;
 592   u32 sw_if_index0;
 593   u32 rx_fib_index0;
 594   snat_session_key_t key0;
 595   snat_session_key_t sm0;
 596   u8 dont_translate = 0;
 597   u8 is_addr_only;
 598   u32 next0 = ~0;
 599   int err;
 600
 601   icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
 602   sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
 603   rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
 604
 605   err = icmp_get_key (ip0, &key0);
 606   if (err != -1)
 607     {
 608       b0->error = node->errors[err];
 609       next0 = SNAT_IN2OUT_NEXT_DROP;
 610       goto out2;
 611     }
 612   key0.fib_index = rx_fib_index0;
 613
 614   if (snat_static_mapping_match(sm, key0, &sm0, 0, &is_addr_only, 0))
 615     {
 616       if (PREDICT_FALSE(snat_not_translate_fast(sm, node, sw_if_index0, ip0,
 617           IP_PROTOCOL_ICMP, rx_fib_index0)))
 618         {
 619           dont_translate = 1;
 620           goto out;
 621         }
 622
 623       if (icmp_is_error_message (icmp0))
 624         {
 625           next0 = SNAT_IN2OUT_NEXT_DROP;
 626           goto out;
 627         }
 628
 629       b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
 630       next0 = SNAT_IN2OUT_NEXT_DROP;
 631       goto out;
 632     }
 633
 634   if (PREDICT_FALSE(icmp0->type != ICMP4_echo_request &&
 635                     (icmp0->type != ICMP4_echo_reply || !is_addr_only) &&
 636                     !icmp_is_error_message (icmp0)))
 637     {
 638       b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
 639       next0 = SNAT_IN2OUT_NEXT_DROP;
 640       goto out;
 641     }
 642
 643 out:
 644   *p_value = sm0;
 645 out2:
 646   *p_proto = key0.protocol;
 647   *p_dont_translate = dont_translate;
 648   return next0;
 649 }
 650
 651 static inline u32 icmp_in2out (snat_main_t *sm,
 652                                vlib_buffer_t * b0,
 653                                ip4_header_t * ip0,
 654                                icmp46_header_t * icmp0,
 655                                u32 sw_if_index0,
 656                                u32 rx_fib_index0,
 657                                vlib_node_runtime_t * node,
 658                                u32 next0,
 659                                u32 thread_index,
 660                                void *d,
 661                                void *e)
 662 {
 663   snat_session_key_t sm0;
 664   u8 protocol;
 665   icmp_echo_header_t *echo0, *inner_echo0 = 0;
 666   ip4_header_t *inner_ip0;
 667   void *l4_header = 0;
 668   icmp46_header_t *inner_icmp0;
 669   u8 dont_translate;
 670   u32 new_addr0, old_addr0;
 671   u16 old_id0, new_id0;
 672   ip_csum_t sum0;
 673   u16 checksum0;
 674   u32 next0_tmp;
 675
 676   echo0 = (icmp_echo_header_t *)(icmp0+1);
 677
 678   next0_tmp = sm->icmp_match_in2out_cb(sm, node, thread_index, b0, ip0,
 679                                        &protocol, &sm0, &dont_translate, d, e);
 680   if (next0_tmp != ~0)
 681     next0 = next0_tmp;
 682   if (next0 == SNAT_IN2OUT_NEXT_DROP || dont_translate)
 683     goto out;
 684
 685   sum0 = ip_incremental_checksum (0, icmp0,
 686                                   ntohs(ip0->length) - ip4_header_bytes (ip0));
 687   checksum0 = ~ip_csum_fold (sum0);
 688   if (PREDICT_FALSE(checksum0 != 0 && checksum0 != 0xffff))
 689     {
 690       next0 = SNAT_IN2OUT_NEXT_DROP;
 691       goto out;
 692     }
 693
 694   old_addr0 = ip0->src_address.as_u32;
 695   new_addr0 = ip0->src_address.as_u32 = sm0.addr.as_u32;
 696   if (vnet_buffer(b0)->sw_if_index[VLIB_TX] == ~0)
 697     vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
 698
 699   sum0 = ip0->checksum;
 700   sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 701                          src_address /* changed member */);
 702   ip0->checksum = ip_csum_fold (sum0);
 703
 704   if (!icmp_is_error_message (icmp0))
 705     {
 706       new_id0 = sm0.port;
 707       if (PREDICT_FALSE(new_id0 != echo0->identifier))
 708         {
 709           old_id0 = echo0->identifier;
 710           new_id0 = sm0.port;
 711           echo0->identifier = new_id0;
 712
 713           sum0 = icmp0->checksum;
 714           sum0 = ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
 715                                  identifier);
 716           icmp0->checksum = ip_csum_fold (sum0);
 717         }
 718     }
 719   else
 720     {
 721       inner_ip0 = (ip4_header_t *)(echo0+1);
 722       l4_header = ip4_next_header (inner_ip0);
 723
 724       if (!ip4_header_checksum_is_valid (inner_ip0))
 725         {
 726           next0 = SNAT_IN2OUT_NEXT_DROP;
 727           goto out;
 728         }
 729
 730       old_addr0 = inner_ip0->dst_address.as_u32;
 731       inner_ip0->dst_address = sm0.addr;
 732       new_addr0 = inner_ip0->dst_address.as_u32;
 733
 734       sum0 = icmp0->checksum;
 735       sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 736                              dst_address /* changed member */);
 737       icmp0->checksum = ip_csum_fold (sum0);
 738
 739       switch (protocol)
 740         {
 741           case SNAT_PROTOCOL_ICMP:
 742             inner_icmp0 = (icmp46_header_t*)l4_header;
 743             inner_echo0 = (icmp_echo_header_t *)(inner_icmp0+1);
 744
 745             old_id0 = inner_echo0->identifier;
 746             new_id0 = sm0.port;
 747             inner_echo0->identifier = new_id0;
 748
 749             sum0 = icmp0->checksum;
 750             sum0 = ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
 751                                    identifier);
 752             icmp0->checksum = ip_csum_fold (sum0);
 753             break;
 754           case SNAT_PROTOCOL_UDP:
 755           case SNAT_PROTOCOL_TCP:
 756             old_id0 = ((tcp_udp_header_t*)l4_header)->dst_port;
 757             new_id0 = sm0.port;
 758             ((tcp_udp_header_t*)l4_header)->dst_port = new_id0;
 759
 760             sum0 = icmp0->checksum;
 761             sum0 = ip_csum_update (sum0, old_id0, new_id0, tcp_udp_header_t,
 762                                    dst_port);
 763             icmp0->checksum = ip_csum_fold (sum0);
 764             break;
 765           default:
 766             ASSERT(0);
 767         }
 768     }
 769
 770 out:
 771   return next0;
 772 }
 773
 774 /**
 775  * @brief Hairpinning
 776  *
 777  * Hairpinning allows two endpoints on the internal side of the NAT to
 778  * communicate even if they only use each other's external IP addresses
 779  * and ports.
 780  *
 781  * @param sm     NAT main.
 782  * @param b0     Vlib buffer.
 783  * @param ip0    IP header.
 784  * @param udp0   UDP header.
 785  * @param tcp0   TCP header.
 786  * @param proto0 NAT protocol.
 787  */
 788 static inline int
 789 snat_hairpinning (snat_main_t *sm,
 790                   vlib_buffer_t * b0,
 791                   ip4_header_t * ip0,
 792                   udp_header_t * udp0,
 793                   tcp_header_t * tcp0,
 794                   u32 proto0)
 795 {
 796   snat_session_key_t key0, sm0;
 797   snat_session_t * s0;
 798   clib_bihash_kv_8_8_t kv0, value0;
 799   ip_csum_t sum0;
 800   u32 new_dst_addr0 = 0, old_dst_addr0, ti = 0, si;
 801   u16 new_dst_port0, old_dst_port0;
 802
 803   key0.addr = ip0->dst_address;
 804   key0.port = udp0->dst_port;
 805   key0.protocol = proto0;
 806   key0.fib_index = sm->outside_fib_index;
 807   kv0.key = key0.as_u64;
 808
 809   /* Check if destination is static mappings */
 810   if (!snat_static_mapping_match(sm, key0, &sm0, 1, 0, 0))
 811     {
 812       new_dst_addr0 = sm0.addr.as_u32;
 813       new_dst_port0 = sm0.port;
 814       vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
 815     }
 816   /* or active session */
 817   else
 818     {
 819       if (sm->num_workers > 1)
 820         ti = (clib_net_to_host_u16 (udp0->dst_port) - 1024) / sm->port_per_thread;
 821       else
 822         ti = sm->num_workers;
 823
 824       if (!clib_bihash_search_8_8 (&sm->per_thread_data[ti].out2in, &kv0, &value0))
 825         {
 826           si = value0.value;
 827
 828           s0 = pool_elt_at_index (sm->per_thread_data[ti].sessions, si);
 829           new_dst_addr0 = s0->in2out.addr.as_u32;
 830           new_dst_port0 = s0->in2out.port;
 831           vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
 832         }
 833     }
 834
 835   /* Destination is behind the same NAT, use internal address and port */
 836   if (new_dst_addr0)
 837     {
 838       old_dst_addr0 = ip0->dst_address.as_u32;
 839       ip0->dst_address.as_u32 = new_dst_addr0;
 840       sum0 = ip0->checksum;
 841       sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
 842                              ip4_header_t, dst_address);
 843       ip0->checksum = ip_csum_fold (sum0);
 844
 845       old_dst_port0 = tcp0->dst;
 846       if (PREDICT_TRUE(new_dst_port0 != old_dst_port0))
 847         {
 848           if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
 849             {
 850               tcp0->dst = new_dst_port0;
 851               sum0 = tcp0->checksum;
 852               sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
 853                                      ip4_header_t, dst_address);
 854               sum0 = ip_csum_update (sum0, old_dst_port0, new_dst_port0,
 855                                      ip4_header_t /* cheat */, length);
 856               tcp0->checksum = ip_csum_fold(sum0);
 857             }
 858           else
 859             {
 860               udp0->dst_port = new_dst_port0;
 861               udp0->checksum = 0;
 862             }
 863         }
 864       else
 865         {
 866           if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
 867             {
 868               sum0 = tcp0->checksum;
 869               sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
 870                                      ip4_header_t, dst_address);
 871               tcp0->checksum = ip_csum_fold(sum0);
 872             }
 873         }
 874       return 1;
 875     }
 876   return 0;
 877 }
 878
 879 static inline void
 880 snat_icmp_hairpinning (snat_main_t *sm,
 881                        vlib_buffer_t * b0,
 882                        ip4_header_t * ip0,
 883                        icmp46_header_t * icmp0)
 884 {
 885   snat_session_key_t key0, sm0;
 886   clib_bihash_kv_8_8_t kv0, value0;
 887   u32 new_dst_addr0 = 0, old_dst_addr0, si, ti = 0;
 888   ip_csum_t sum0;
 889   snat_session_t *s0;
 890
 891   if (!icmp_is_error_message (icmp0))
 892     {
 893       icmp_echo_header_t *echo0 = (icmp_echo_header_t *)(icmp0+1);
 894       u16 icmp_id0 = echo0->identifier;
 895       key0.addr = ip0->dst_address;
 896       key0.port = icmp_id0;
 897       key0.protocol = SNAT_PROTOCOL_ICMP;
 898       key0.fib_index = sm->outside_fib_index;
 899       kv0.key = key0.as_u64;
 900
 901       if (sm->num_workers > 1)
 902         ti = (clib_net_to_host_u16 (icmp_id0) - 1024) / sm->port_per_thread;
 903       else
 904         ti = sm->num_workers;
 905
 906       /* Check if destination is in active sessions */
 907       if (clib_bihash_search_8_8 (&sm->per_thread_data[ti].out2in, &kv0,
 908                                   &value0))
 909         {
 910           /* or static mappings */
 911           if (!snat_static_mapping_match(sm, key0, &sm0, 1, 0, 0))
 912             {
 913               new_dst_addr0 = sm0.addr.as_u32;
 914               vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
 915             }
 916         }
 917       else
 918         {
 919           si = value0.value;
 920
 921           s0 = pool_elt_at_index (sm->per_thread_data[ti].sessions, si);
 922           new_dst_addr0 = s0->in2out.addr.as_u32;
 923           vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
 924           echo0->identifier = s0->in2out.port;
 925           sum0 = icmp0->checksum;
 926           sum0 = ip_csum_update (sum0, icmp_id0, s0->in2out.port,
 927                                  icmp_echo_header_t, identifier);
 928           icmp0->checksum = ip_csum_fold (sum0);
 929         }
 930
 931       /* Destination is behind the same NAT, use internal address and port */
 932       if (new_dst_addr0)
 933         {
 934           old_dst_addr0 = ip0->dst_address.as_u32;
 935           ip0->dst_address.as_u32 = new_dst_addr0;
 936           sum0 = ip0->checksum;
 937           sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
 938                                  ip4_header_t, dst_address);
 939           ip0->checksum = ip_csum_fold (sum0);
 940         }
 941     }
 942
 943 }
 944
 945 static inline u32 icmp_in2out_slow_path (snat_main_t *sm,
 946                                          vlib_buffer_t * b0,
 947                                          ip4_header_t * ip0,
 948                                          icmp46_header_t * icmp0,
 949                                          u32 sw_if_index0,
 950                                          u32 rx_fib_index0,
 951                                          vlib_node_runtime_t * node,
 952                                          u32 next0,
 953                                          f64 now,
 954                                          u32 thread_index,
 955                                          snat_session_t ** p_s0)
 956 {
 957   next0 = icmp_in2out(sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
 958                       next0, thread_index, p_s0, 0);
 959   snat_session_t * s0 = *p_s0;
 960   if (PREDICT_TRUE(next0 != SNAT_IN2OUT_NEXT_DROP && s0))
 961     {
 962       /* Hairpinning */
 963       if (vnet_buffer(b0)->sw_if_index[VLIB_TX] == 0)
 964         snat_icmp_hairpinning(sm, b0, ip0, icmp0);
 965       /* Accounting */
 966       s0->last_heard = now;
 967       s0->total_pkts++;
 968       s0->total_bytes += vlib_buffer_length_in_chain (sm->vlib_main, b0);
 969       /* Per-user LRU list maintenance */
 970       clib_dlist_remove (sm->per_thread_data[thread_index].list_pool,
 971                          s0->per_user_index);
 972       clib_dlist_addtail (sm->per_thread_data[thread_index].list_pool,
 973                           s0->per_user_list_head_index,
 974                           s0->per_user_index);
 975     }
 976   return next0;
 977 }
 978 static inline void
 979 snat_hairpinning_unknown_proto (snat_main_t *sm,
 980                                 vlib_buffer_t * b,
 981                                 ip4_header_t * ip)
 982 {
 983   u32 old_addr, new_addr = 0, ti = 0;
 984   clib_bihash_kv_8_8_t kv, value;
 985   clib_bihash_kv_16_8_t s_kv, s_value;
 986   nat_ed_ses_key_t key;
 987   snat_session_key_t m_key;
 988   snat_static_mapping_t *m;
 989   ip_csum_t sum;
 990   snat_session_t *s;
 991
 992   old_addr = ip->dst_address.as_u32;
 993   key.l_addr.as_u32 = ip->dst_address.as_u32;
 994   key.r_addr.as_u32 = ip->src_address.as_u32;
 995   key.fib_index = sm->outside_fib_index;
 996   key.proto = ip->protocol;
 997   key.r_port = 0;
 998   key.l_port = 0;
 999   s_kv.key[0] = key.as_u64[0];
1000   s_kv.key[1] = key.as_u64[1];
1001   if (clib_bihash_search_16_8 (&sm->out2in_ed, &s_kv, &s_value))
1002     {
1003       m_key.addr = ip->dst_address;
1004       m_key.fib_index = sm->outside_fib_index;
1005       m_key.port = 0;
1006       m_key.protocol = 0;
1007       kv.key = m_key.as_u64;
1008       if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
1009         return;
1010
1011       m = pool_elt_at_index (sm->static_mappings, value.value);
1012       if (vnet_buffer(b)->sw_if_index[VLIB_TX] == ~0)
1013         vnet_buffer(b)->sw_if_index[VLIB_TX] = m->fib_index;
1014       new_addr = ip->dst_address.as_u32 = m->local_addr.as_u32;
1015     }
1016   else
1017     {
1018       if (sm->num_workers > 1)
1019         ti = sm->worker_out2in_cb (ip, sm->outside_fib_index);
1020       else
1021         ti = sm->num_workers;
1022
1023       s = pool_elt_at_index (sm->per_thread_data[ti].sessions, s_value.value);
1024       if (vnet_buffer(b)->sw_if_index[VLIB_TX] == ~0)
1025         vnet_buffer(b)->sw_if_index[VLIB_TX] = s->in2out.fib_index;
1026       new_addr = ip->dst_address.as_u32 = s->in2out.addr.as_u32;
1027     }
1028   sum = ip->checksum;
1029   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
1030   ip->checksum = ip_csum_fold (sum);
1031 }
1032
1033 static snat_session_t *
1034 snat_in2out_unknown_proto (snat_main_t *sm,
1035                            vlib_buffer_t * b,
1036                            ip4_header_t * ip,
1037                            u32 rx_fib_index,
1038                            u32 thread_index,
1039                            f64 now,
1040                            vlib_main_t * vm,
1041                            vlib_node_runtime_t * node)
1042 {
1043   clib_bihash_kv_8_8_t kv, value;
1044   clib_bihash_kv_16_8_t s_kv, s_value;
1045   snat_static_mapping_t *m;
1046   snat_session_key_t m_key;
1047   u32 old_addr, new_addr = 0;
1048   ip_csum_t sum;
1049   snat_user_t *u;
1050   dlist_elt_t *head, *elt;
1051   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
1052   u32 elt_index, head_index, ses_index;
1053   snat_session_t * s;
1054   nat_ed_ses_key_t key;
1055   u32 address_index = ~0;
1056   int i;
1057   u8 is_sm = 0;
1058
1059   old_addr = ip->src_address.as_u32;
1060
1061   key.l_addr = ip->src_address;
1062   key.r_addr = ip->dst_address;
1063   key.fib_index = rx_fib_index;
1064   key.proto = ip->protocol;
1065   key.l_port = 0;
1066   key.l_port = 0;
1067   s_kv.key[0] = key.as_u64[0];
1068   s_kv.key[1] = key.as_u64[1];
1069
1070   if (!clib_bihash_search_16_8 (&sm->in2out_ed, &s_kv, &s_value))
1071     {
1072       s = pool_elt_at_index (tsm->sessions, s_value.value);
1073       new_addr = ip->src_address.as_u32 = s->out2in.addr.as_u32;
1074     }
1075   else
1076     {
1077       if (PREDICT_FALSE (maximum_sessions_exceeded(sm, thread_index)))
1078         {
1079           b->error = node->errors[SNAT_IN2OUT_ERROR_MAX_SESSIONS_EXCEEDED];
1080           nat_ipfix_logging_max_sessions(sm->max_translations);
1081           return 0;
1082         }
1083
1084       u = nat_user_get_or_create (sm, &ip->src_address, rx_fib_index,
1085                                   thread_index);
1086       if (!u)
1087         {
1088           clib_warning ("create NAT user failed");
1089           return 0;
1090         }
1091
1092       m_key.addr = ip->src_address;
1093       m_key.port = 0;
1094       m_key.protocol = 0;
1095       m_key.fib_index = rx_fib_index;
1096       kv.key = m_key.as_u64;
1097
1098       /* Try to find static mapping first */
1099       if (!clib_bihash_search_8_8 (&sm->static_mapping_by_local, &kv, &value))
1100         {
1101           m = pool_elt_at_index (sm->static_mappings, value.value);
1102           new_addr = ip->src_address.as_u32 = m->external_addr.as_u32;
1103           is_sm = 1;
1104           goto create_ses;
1105         }
1106       /* Fallback to 3-tuple key */
1107       else
1108         {
1109           /* Choose same out address as for TCP/UDP session to same destination */
1110           if (!clib_bihash_search_8_8 (&tsm->user_hash, &kv, &value))
1111             {
1112               head_index = u->sessions_per_user_list_head_index;
1113               head = pool_elt_at_index (tsm->list_pool, head_index);
1114               elt_index = head->next;
1115               elt = pool_elt_at_index (tsm->list_pool, elt_index);
1116               ses_index = elt->value;
1117               while (ses_index != ~0)
1118                 {
1119                   s =  pool_elt_at_index (tsm->sessions, ses_index);
1120                   elt_index = elt->next;
1121                   elt = pool_elt_at_index (tsm->list_pool, elt_index);
1122                   ses_index = elt->value;
1123
1124                   if (s->ext_host_addr.as_u32 == ip->dst_address.as_u32)
1125                     {
1126                       new_addr = ip->src_address.as_u32 = s->out2in.addr.as_u32;
1127                       address_index = s->outside_address_index;
1128
1129                       key.fib_index = sm->outside_fib_index;
1130                       key.l_addr.as_u32 = new_addr;
1131                       s_kv.key[0] = key.as_u64[0];
1132                       s_kv.key[1] = key.as_u64[1];
1133                       if (clib_bihash_search_16_8 (&sm->out2in_ed, &s_kv, &s_value))
1134                         break;
1135
1136                       goto create_ses;
1137                     }
1138                 }
1139             }
1140           key.fib_index = sm->outside_fib_index;
1141           for (i = 0; i < vec_len (sm->addresses); i++)
1142             {
1143               key.l_addr.as_u32 = sm->addresses[i].addr.as_u32;
1144               s_kv.key[0] = key.as_u64[0];
1145               s_kv.key[1] = key.as_u64[1];
1146               if (clib_bihash_search_16_8 (&sm->out2in_ed, &s_kv, &s_value))
1147                 {
1148                   new_addr = ip->src_address.as_u32 = key.l_addr.as_u32;
1149                   address_index = i;
1150                   goto create_ses;
1151                 }
1152             }
1153           return 0;
1154         }
1155
1156 create_ses:
1157       s = nat_session_alloc_or_recycle (sm, u, thread_index);
1158       if (!s)
1159         {
1160           clib_warning ("create NAT session failed");
1161           return 0;
1162         }
1163
1164       s->ext_host_addr.as_u32 = ip->dst_address.as_u32;
1165       s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
1166       s->outside_address_index = address_index;
1167       s->out2in.addr.as_u32 = new_addr;
1168       s->out2in.fib_index = sm->outside_fib_index;
1169       s->in2out.addr.as_u32 = old_addr;
1170       s->in2out.fib_index = rx_fib_index;
1171       s->in2out.port = s->out2in.port = ip->protocol;
1172       if (is_sm)
1173         {
1174           u->nstaticsessions++;
1175           s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
1176         }
1177       else
1178         {
1179           u->nsessions++;
1180         }
1181
1182       /* Add to lookup tables */
1183       key.l_addr.as_u32 = old_addr;
1184       key.r_addr = ip->dst_address;
1185       key.proto = ip->protocol;
1186       key.fib_index = rx_fib_index;
1187       s_kv.key[0] = key.as_u64[0];
1188       s_kv.key[1] = key.as_u64[1];
1189       s_kv.value = s - tsm->sessions;
1190       if (clib_bihash_add_del_16_8 (&sm->in2out_ed, &s_kv, 1))
1191         clib_warning ("in2out key add failed");
1192
1193       key.l_addr.as_u32 = new_addr;
1194       key.fib_index = sm->outside_fib_index;
1195       s_kv.key[0] = key.as_u64[0];
1196       s_kv.key[1] = key.as_u64[1];
1197       if (clib_bihash_add_del_16_8 (&sm->out2in_ed, &s_kv, 1))
1198         clib_warning ("out2in key add failed");
1199   }
1200
1201   /* Update IP checksum */
1202   sum = ip->checksum;
1203   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, src_address);
1204   ip->checksum = ip_csum_fold (sum);
1205
1206   /* Accounting */
1207   s->last_heard = now;
1208   s->total_pkts++;
1209   s->total_bytes += vlib_buffer_length_in_chain (vm, b);
1210   /* Per-user LRU list maintenance */
1211   clib_dlist_remove (tsm->list_pool, s->per_user_index);
1212   clib_dlist_addtail (tsm->list_pool, s->per_user_list_head_index,
1213                       s->per_user_index);
1214
1215   /* Hairpinning */
1216   if (vnet_buffer(b)->sw_if_index[VLIB_TX] == ~0)
1217     snat_hairpinning_unknown_proto(sm, b, ip);
1218
1219   if (vnet_buffer(b)->sw_if_index[VLIB_TX] == ~0)
1220     vnet_buffer(b)->sw_if_index[VLIB_TX] = sm->outside_fib_index;
1221
1222   return s;
1223 }
1224
1225 static snat_session_t *
1226 snat_in2out_lb (snat_main_t *sm,
1227                 vlib_buffer_t * b,
1228                 ip4_header_t * ip,
1229                 u32 rx_fib_index,
1230                 u32 thread_index,
1231                 f64 now,
1232                 vlib_main_t * vm,
1233                 vlib_node_runtime_t * node)
1234 {
1235   nat_ed_ses_key_t key;
1236   clib_bihash_kv_16_8_t s_kv, s_value;
1237   udp_header_t *udp = ip4_next_header (ip);
1238   tcp_header_t *tcp = (tcp_header_t *) udp;
1239   snat_session_t *s = 0;
1240   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
1241   u32 old_addr, new_addr;
1242   u16 new_port, old_port;
1243   ip_csum_t sum;
1244   u32 proto = ip_proto_to_snat_proto (ip->protocol);
1245   snat_session_key_t e_key, l_key;
1246   snat_user_t *u;
1247
1248   old_addr = ip->src_address.as_u32;
1249
1250   key.l_addr = ip->src_address;
1251   key.r_addr = ip->dst_address;
1252   key.fib_index = rx_fib_index;
1253   key.proto = ip->protocol;
1254   key.r_port = udp->dst_port;
1255   key.l_port = udp->src_port;
1256   s_kv.key[0] = key.as_u64[0];
1257   s_kv.key[1] = key.as_u64[1];
1258
1259   if (!clib_bihash_search_16_8 (&sm->in2out_ed, &s_kv, &s_value))
1260     {
1261       s = pool_elt_at_index (tsm->sessions, s_value.value);
1262     }
1263   else
1264     {
1265       if (PREDICT_FALSE (maximum_sessions_exceeded (sm, thread_index)))
1266         {
1267           b->error = node->errors[SNAT_IN2OUT_ERROR_MAX_SESSIONS_EXCEEDED];
1268           nat_ipfix_logging_max_sessions(sm->max_translations);
1269           return 0;
1270         }
1271
1272       l_key.addr = ip->src_address;
1273       l_key.port = udp->src_port;
1274       l_key.protocol = proto;
1275       l_key.fib_index = rx_fib_index;
1276       if (snat_static_mapping_match(sm, l_key, &e_key, 0, 0, 0))
1277         return 0;
1278
1279       u = nat_user_get_or_create (sm, &ip->src_address, rx_fib_index,
1280                                   thread_index);
1281       if (!u)
1282         {
1283           clib_warning ("create NAT user failed");
1284           return 0;
1285         }
1286
1287       s = nat_session_alloc_or_recycle (sm, u, thread_index);
1288       if (!s)
1289         {
1290           clib_warning ("create NAT session failed");
1291           return 0;
1292         }
1293
1294       s->ext_host_addr.as_u32 = ip->dst_address.as_u32;
1295       s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
1296       s->flags |= SNAT_SESSION_FLAG_LOAD_BALANCING;
1297       s->outside_address_index = ~0;
1298       s->in2out = l_key;
1299       s->out2in = e_key;
1300       u->nstaticsessions++;
1301
1302       /* Add to lookup tables */
1303       s_kv.value = s - tsm->sessions;
1304       if (clib_bihash_add_del_16_8 (&sm->in2out_ed, &s_kv, 1))
1305         clib_warning ("in2out-ed key add failed");
1306
1307       key.l_addr = e_key.addr;
1308       key.fib_index = e_key.fib_index;
1309       key.l_port = e_key.port;
1310       s_kv.key[0] = key.as_u64[0];
1311       s_kv.key[1] = key.as_u64[1];
1312       if (clib_bihash_add_del_16_8 (&sm->out2in_ed, &s_kv, 1))
1313         clib_warning ("out2in-ed key add failed");
1314     }
1315
1316   new_addr = ip->src_address.as_u32 = s->out2in.addr.as_u32;
1317
1318   /* Update IP checksum */
1319   sum = ip->checksum;
1320   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, src_address);
1321   if (is_twice_nat_session (s))
1322     sum = ip_csum_update (sum, ip->dst_address.as_u32,
1323                           s->ext_host_addr.as_u32, ip4_header_t, dst_address);
1324   ip->checksum = ip_csum_fold (sum);
1325
1326   if (PREDICT_TRUE(proto == SNAT_PROTOCOL_TCP))
1327     {
1328       old_port = tcp->src_port;
1329       tcp->src_port = s->out2in.port;
1330       new_port = tcp->src_port;
1331
1332       sum = tcp->checksum;
1333       sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, src_address);
1334       sum = ip_csum_update (sum, old_port, new_port, ip4_header_t, length);
1335       if (is_twice_nat_session (s))
1336         {
1337           sum = ip_csum_update (sum, ip->dst_address.as_u32,
1338                                 s->ext_host_addr.as_u32, ip4_header_t,
1339                                 dst_address);
1340           sum = ip_csum_update (sum, tcp->dst_port, s->ext_host_port,
1341                                 ip4_header_t, length);
1342           tcp->dst_port = s->ext_host_port;
1343           ip->dst_address.as_u32 = s->ext_host_addr.as_u32;
1344         }
1345       tcp->checksum = ip_csum_fold(sum);
1346     }
1347   else
1348     {
1349       udp->src_port = s->out2in.port;
1350       if (is_twice_nat_session (s))
1351         {
1352           udp->dst_port = s->ext_host_port;
1353           ip->dst_address.as_u32 = s->ext_host_addr.as_u32;
1354         }
1355       udp->checksum = 0;
1356     }
1357
1358   if (vnet_buffer(b)->sw_if_index[VLIB_TX] == ~0)
1359     vnet_buffer(b)->sw_if_index[VLIB_TX] = sm->outside_fib_index;
1360
1361   /* Accounting */
1362   s->last_heard = now;
1363   s->total_pkts++;
1364   s->total_bytes += vlib_buffer_length_in_chain (vm, b);
1365   /* Per-user LRU list maintenance */
1366   clib_dlist_remove (tsm->list_pool, s->per_user_index);
1367   clib_dlist_addtail (tsm->list_pool, s->per_user_list_head_index,
1368                       s->per_user_index);
1369   return s;
1370 }
1371
1372 static inline uword
1373 snat_in2out_node_fn_inline (vlib_main_t * vm,
1374                             vlib_node_runtime_t * node,
1375                             vlib_frame_t * frame, int is_slow_path,
1376                             int is_output_feature)
1377 {
1378   u32 n_left_from, * from, * to_next;
1379   snat_in2out_next_t next_index;
1380   u32 pkts_processed = 0;
1381   snat_main_t * sm = &snat_main;
1382   f64 now = vlib_time_now (vm);
1383   u32 stats_node_index;
1384   u32 thread_index = vlib_get_thread_index ();
1385
1386   stats_node_index = is_slow_path ? snat_in2out_slowpath_node.index :
1387     snat_in2out_node.index;
1388
1389   from = vlib_frame_vector_args (frame);
1390   n_left_from = frame->n_vectors;
1391   next_index = node->cached_next_index;
1392
1393   while (n_left_from > 0)
1394     {
1395       u32 n_left_to_next;
1396
1397       vlib_get_next_frame (vm, node, next_index,
1398                            to_next, n_left_to_next);
1399
1400       while (n_left_from >= 4 && n_left_to_next >= 2)
1401         {
1402           u32 bi0, bi1;
1403           vlib_buffer_t * b0, * b1;
1404           u32 next0, next1;
1405           u32 sw_if_index0, sw_if_index1;
1406           ip4_header_t * ip0, * ip1;
1407           ip_csum_t sum0, sum1;
1408           u32 new_addr0, old_addr0, new_addr1, old_addr1;
1409           u16 old_port0, new_port0, old_port1, new_port1;
1410           udp_header_t * udp0, * udp1;
1411           tcp_header_t * tcp0, * tcp1;
1412           icmp46_header_t * icmp0, * icmp1;
1413           snat_session_key_t key0, key1;
1414           u32 rx_fib_index0, rx_fib_index1;
1415           u32 proto0, proto1;
1416           snat_session_t * s0 = 0, * s1 = 0;
1417           clib_bihash_kv_8_8_t kv0, value0, kv1, value1;
1418           u32 iph_offset0 = 0, iph_offset1 = 0;
1419
1420           /* Prefetch next iteration. */
1421           {
1422             vlib_buffer_t * p2, * p3;
1423
1424             p2 = vlib_get_buffer (vm, from[2]);
1425             p3 = vlib_get_buffer (vm, from[3]);
1426
1427             vlib_prefetch_buffer_header (p2, LOAD);
1428             vlib_prefetch_buffer_header (p3, LOAD);
1429
1430             CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE);
1431             CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE);
1432           }
1433
1434           /* speculatively enqueue b0 and b1 to the current next frame */
1435           to_next[0] = bi0 = from[0];
1436           to_next[1] = bi1 = from[1];
1437           from += 2;
1438           to_next += 2;
1439           n_left_from -= 2;
1440           n_left_to_next -= 2;
1441
1442           b0 = vlib_get_buffer (vm, bi0);
1443           b1 = vlib_get_buffer (vm, bi1);
1444
1445           if (is_output_feature)
1446             iph_offset0 = vnet_buffer (b0)->ip.save_rewrite_length;
1447
1448           ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
1449                  iph_offset0);
1450
1451           udp0 = ip4_next_header (ip0);
1452           tcp0 = (tcp_header_t *) udp0;
1453           icmp0 = (icmp46_header_t *) udp0;
1454
1455           sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
1456           rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
1457                                    sw_if_index0);
1458
1459           next0 = next1 = SNAT_IN2OUT_NEXT_LOOKUP;
1460
1461           if (PREDICT_FALSE(ip0->ttl == 1))
1462             {
1463               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1464               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1465                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1466                                            0);
1467               next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
1468               goto trace00;
1469             }
1470
1471           proto0 = ip_proto_to_snat_proto (ip0->protocol);
1472
1473           /* Next configured feature, probably ip4-lookup */
1474           if (is_slow_path)
1475             {
1476               if (PREDICT_FALSE (proto0 == ~0))
1477                 {
1478                   s0 = snat_in2out_unknown_proto (sm, b0, ip0, rx_fib_index0,
1479                                                   thread_index, now, vm, node);
1480                   if (!s0)
1481                     next0 = SNAT_IN2OUT_NEXT_DROP;
1482                   goto trace00;
1483                 }
1484
1485               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1486                 {
1487                   next0 = icmp_in2out_slow_path
1488                     (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0,
1489                      node, next0, now, thread_index, &s0);
1490                   goto trace00;
1491                 }
1492             }
1493           else
1494             {
1495               if (PREDICT_FALSE (proto0 == ~0 || proto0 == SNAT_PROTOCOL_ICMP))
1496                 {
1497                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1498                   goto trace00;
1499                 }
1500
1501               if (ip4_is_fragment (ip0))
1502                 {
1503                   next0 = SNAT_IN2OUT_NEXT_REASS;
1504                   goto trace00;
1505                 }
1506             }
1507
1508           key0.addr = ip0->src_address;
1509           key0.port = udp0->src_port;
1510           key0.protocol = proto0;
1511           key0.fib_index = rx_fib_index0;
1512
1513           kv0.key = key0.as_u64;
1514
1515           if (PREDICT_FALSE (clib_bihash_search_8_8 (
1516               &sm->per_thread_data[thread_index].in2out, &kv0, &value0) != 0))
1517             {
1518               if (is_slow_path)
1519                 {
1520                   if (PREDICT_FALSE(snat_not_translate(sm, node, sw_if_index0,
1521                       ip0, proto0, rx_fib_index0, thread_index)) && !is_output_feature)
1522                     goto trace00;
1523
1524                   next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0,
1525                                      &s0, node, next0, thread_index);
1526                   if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
1527                     goto trace00;
1528                 }
1529               else
1530                 {
1531                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1532                   goto trace00;
1533                 }
1534             }
1535           else
1536             {
1537               if (PREDICT_FALSE (value0.value == ~0ULL))
1538                 {
1539                   if (is_slow_path)
1540                     {
1541                       s0 = snat_in2out_lb(sm, b0, ip0, rx_fib_index0,
1542                                           thread_index, now, vm, node);
1543                       if (!s0 && !sm->forwarding_enabled)
1544                         next0 = SNAT_IN2OUT_NEXT_DROP;
1545                       goto trace00;
1546                     }
1547                   else
1548                     {
1549                       next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1550                       goto trace00;
1551                     }
1552                 }
1553               else
1554                 {
1555                   s0 = pool_elt_at_index (
1556                     sm->per_thread_data[thread_index].sessions,
1557                     value0.value);
1558                 }
1559             }
1560
1561           b0->flags |= VNET_BUFFER_F_IS_NATED;
1562
1563           old_addr0 = ip0->src_address.as_u32;
1564           ip0->src_address = s0->out2in.addr;
1565           new_addr0 = ip0->src_address.as_u32;
1566           if (!is_output_feature)
1567             vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
1568
1569           sum0 = ip0->checksum;
1570           sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1571                                  ip4_header_t,
1572                                  src_address /* changed member */);
1573           ip0->checksum = ip_csum_fold (sum0);
1574
1575           if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
1576             {
1577               old_port0 = tcp0->src_port;
1578               tcp0->src_port = s0->out2in.port;
1579               new_port0 = tcp0->src_port;
1580
1581               sum0 = tcp0->checksum;
1582               sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1583                                      ip4_header_t,
1584                                      dst_address /* changed member */);
1585               sum0 = ip_csum_update (sum0, old_port0, new_port0,
1586                                      ip4_header_t /* cheat */,
1587                                      length /* changed member */);
1588               tcp0->checksum = ip_csum_fold(sum0);
1589             }
1590           else
1591             {
1592               old_port0 = udp0->src_port;
1593               udp0->src_port = s0->out2in.port;
1594               udp0->checksum = 0;
1595             }
1596
1597           /* Accounting */
1598           s0->last_heard = now;
1599           s0->total_pkts++;
1600           s0->total_bytes += vlib_buffer_length_in_chain (vm, b0);
1601           /* Per-user LRU list maintenance */
1602           clib_dlist_remove (sm->per_thread_data[thread_index].list_pool,
1603                              s0->per_user_index);
1604           clib_dlist_addtail (sm->per_thread_data[thread_index].list_pool,
1605                               s0->per_user_list_head_index,
1606                               s0->per_user_index);
1607         trace00:
1608
1609           if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
1610                             && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1611             {
1612               snat_in2out_trace_t *t =
1613                  vlib_add_trace (vm, node, b0, sizeof (*t));
1614               t->is_slow_path = is_slow_path;
1615               t->sw_if_index = sw_if_index0;
1616               t->next_index = next0;
1617                   t->session_index = ~0;
1618               if (s0)
1619                 t->session_index = s0 - sm->per_thread_data[thread_index].sessions;
1620             }
1621
1622           pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
1623
1624           if (is_output_feature)
1625             iph_offset1 = vnet_buffer (b1)->ip.save_rewrite_length;
1626
1627           ip1 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b1) +
1628                  iph_offset1);
1629
1630           udp1 = ip4_next_header (ip1);
1631           tcp1 = (tcp_header_t *) udp1;
1632           icmp1 = (icmp46_header_t *) udp1;
1633
1634           sw_if_index1 = vnet_buffer(b1)->sw_if_index[VLIB_RX];
1635           rx_fib_index1 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
1636                                    sw_if_index1);
1637
1638           if (PREDICT_FALSE(ip1->ttl == 1))
1639             {
1640               vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1641               icmp4_error_set_vnet_buffer (b1, ICMP4_time_exceeded,
1642                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1643                                            0);
1644               next1 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
1645               goto trace01;
1646             }
1647
1648           proto1 = ip_proto_to_snat_proto (ip1->protocol);
1649
1650           /* Next configured feature, probably ip4-lookup */
1651           if (is_slow_path)
1652             {
1653               if (PREDICT_FALSE (proto1 == ~0))
1654                 {
1655                   s1 = snat_in2out_unknown_proto (sm, b1, ip1, rx_fib_index1,
1656                                                   thread_index, now, vm, node);
1657                   if (!s1)
1658                     next1 = SNAT_IN2OUT_NEXT_DROP;
1659                   goto trace01;
1660                 }
1661
1662               if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP))
1663                 {
1664                   next1 = icmp_in2out_slow_path
1665                     (sm, b1, ip1, icmp1, sw_if_index1, rx_fib_index1, node,
1666                      next1, now, thread_index, &s1);
1667                   goto trace01;
1668                 }
1669             }
1670           else
1671             {
1672               if (PREDICT_FALSE (proto1 == ~0 || proto1 == SNAT_PROTOCOL_ICMP))
1673                 {
1674                   next1 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1675                   goto trace01;
1676                 }
1677
1678               if (ip4_is_fragment (ip1))
1679                 {
1680                   next1 = SNAT_IN2OUT_NEXT_REASS;
1681                   goto trace01;
1682                 }
1683             }
1684
1685           b1->flags |= VNET_BUFFER_F_IS_NATED;
1686
1687           key1.addr = ip1->src_address;
1688           key1.port = udp1->src_port;
1689           key1.protocol = proto1;
1690           key1.fib_index = rx_fib_index1;
1691
1692           kv1.key = key1.as_u64;
1693
1694             if (PREDICT_FALSE(clib_bihash_search_8_8 (
1695                 &sm->per_thread_data[thread_index].in2out, &kv1, &value1) != 0))
1696             {
1697               if (is_slow_path)
1698                 {
1699                   if (PREDICT_FALSE(snat_not_translate(sm, node, sw_if_index1,
1700                       ip1, proto1, rx_fib_index1, thread_index)) && !is_output_feature)
1701                     goto trace01;
1702
1703                   next1 = slow_path (sm, b1, ip1, rx_fib_index1, &key1,
1704                                      &s1, node, next1, thread_index);
1705                   if (PREDICT_FALSE (next1 == SNAT_IN2OUT_NEXT_DROP))
1706                     goto trace01;
1707                 }
1708               else
1709                 {
1710                   next1 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1711                   goto trace01;
1712                 }
1713             }
1714           else
1715             {
1716               if (PREDICT_FALSE (value1.value == ~0ULL))
1717                 {
1718                   if (is_slow_path)
1719                     {
1720                       s1 = snat_in2out_lb(sm, b1, ip1, rx_fib_index1,
1721                                           thread_index, now, vm, node);
1722                       if (!s1 && !sm->forwarding_enabled)
1723                         next1 = SNAT_IN2OUT_NEXT_DROP;
1724                       goto trace01;
1725                     }
1726                   else
1727                     {
1728                       next1 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1729                       goto trace01;
1730                     }
1731                 }
1732               else
1733                 {
1734                   s1 = pool_elt_at_index (
1735                     sm->per_thread_data[thread_index].sessions,
1736                     value1.value);
1737                 }
1738             }
1739
1740           old_addr1 = ip1->src_address.as_u32;
1741           ip1->src_address = s1->out2in.addr;
1742           new_addr1 = ip1->src_address.as_u32;
1743           if (!is_output_feature)
1744             vnet_buffer(b1)->sw_if_index[VLIB_TX] = s1->out2in.fib_index;
1745
1746           sum1 = ip1->checksum;
1747           sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
1748                                  ip4_header_t,
1749                                  src_address /* changed member */);
1750           ip1->checksum = ip_csum_fold (sum1);
1751
1752           if (PREDICT_TRUE(proto1 == SNAT_PROTOCOL_TCP))
1753             {
1754               old_port1 = tcp1->src_port;
1755               tcp1->src_port = s1->out2in.port;
1756               new_port1 = tcp1->src_port;
1757
1758               sum1 = tcp1->checksum;
1759               sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
1760                                      ip4_header_t,
1761                                      dst_address /* changed member */);
1762               sum1 = ip_csum_update (sum1, old_port1, new_port1,
1763                                      ip4_header_t /* cheat */,
1764                                      length /* changed member */);
1765               tcp1->checksum = ip_csum_fold(sum1);
1766             }
1767           else
1768             {
1769               old_port1 = udp1->src_port;
1770               udp1->src_port = s1->out2in.port;
1771               udp1->checksum = 0;
1772             }
1773
1774           /* Accounting */
1775           s1->last_heard = now;
1776           s1->total_pkts++;
1777           s1->total_bytes += vlib_buffer_length_in_chain (vm, b1);
1778           /* Per-user LRU list maintenance */
1779           clib_dlist_remove (sm->per_thread_data[thread_index].list_pool,
1780                              s1->per_user_index);
1781           clib_dlist_addtail (sm->per_thread_data[thread_index].list_pool,
1782                               s1->per_user_list_head_index,
1783                               s1->per_user_index);
1784         trace01:
1785
1786           if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
1787                             && (b1->flags & VLIB_BUFFER_IS_TRACED)))
1788             {
1789               snat_in2out_trace_t *t =
1790                  vlib_add_trace (vm, node, b1, sizeof (*t));
1791               t->sw_if_index = sw_if_index1;
1792               t->next_index = next1;
1793               t->session_index = ~0;
1794               if (s1)
1795                 t->session_index = s1 - sm->per_thread_data[thread_index].sessions;
1796             }
1797
1798           pkts_processed += next1 != SNAT_IN2OUT_NEXT_DROP;
1799
1800           /* verify speculative enqueues, maybe switch current next frame */
1801           vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
1802                                            to_next, n_left_to_next,
1803                                            bi0, bi1, next0, next1);
1804         }
1805
1806       while (n_left_from > 0 && n_left_to_next > 0)
1807         {
1808           u32 bi0;
1809           vlib_buffer_t * b0;
1810           u32 next0;
1811           u32 sw_if_index0;
1812           ip4_header_t * ip0;
1813           ip_csum_t sum0;
1814           u32 new_addr0, old_addr0;
1815           u16 old_port0, new_port0;
1816           udp_header_t * udp0;
1817           tcp_header_t * tcp0;
1818           icmp46_header_t * icmp0;
1819           snat_session_key_t key0;
1820           u32 rx_fib_index0;
1821           u32 proto0;
1822           snat_session_t * s0 = 0;
1823           clib_bihash_kv_8_8_t kv0, value0;
1824           u32 iph_offset0 = 0;
1825
1826           /* speculatively enqueue b0 to the current next frame */
1827           bi0 = from[0];
1828           to_next[0] = bi0;
1829           from += 1;
1830           to_next += 1;
1831           n_left_from -= 1;
1832           n_left_to_next -= 1;
1833
1834           b0 = vlib_get_buffer (vm, bi0);
1835           next0 = SNAT_IN2OUT_NEXT_LOOKUP;
1836
1837           if (is_output_feature)
1838             iph_offset0 = vnet_buffer (b0)->ip.save_rewrite_length;
1839
1840           ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
1841                  iph_offset0);
1842
1843           udp0 = ip4_next_header (ip0);
1844           tcp0 = (tcp_header_t *) udp0;
1845           icmp0 = (icmp46_header_t *) udp0;
1846
1847           sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
1848           rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
1849                                    sw_if_index0);
1850
1851           if (PREDICT_FALSE(ip0->ttl == 1))
1852             {
1853               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1854               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1855                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1856                                            0);
1857               next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
1858               goto trace0;
1859             }
1860
1861           proto0 = ip_proto_to_snat_proto (ip0->protocol);
1862
1863           /* Next configured feature, probably ip4-lookup */
1864           if (is_slow_path)
1865             {
1866               if (PREDICT_FALSE (proto0 == ~0))
1867                 {
1868                   s0 = snat_in2out_unknown_proto (sm, b0, ip0, rx_fib_index0,
1869                                                   thread_index, now, vm, node);
1870                   if (!s0)
1871                     next0 = SNAT_IN2OUT_NEXT_DROP;
1872                   goto trace0;
1873                 }
1874
1875               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1876                 {
1877                   next0 = icmp_in2out_slow_path
1878                     (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1879                      next0, now, thread_index, &s0);
1880                   goto trace0;
1881                 }
1882             }
1883           else
1884             {
1885               if (PREDICT_FALSE (proto0 == ~0 || proto0 == SNAT_PROTOCOL_ICMP))
1886                 {
1887                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1888                   goto trace0;
1889                 }
1890
1891               if (ip4_is_fragment (ip0))
1892                 {
1893                   next0 = SNAT_IN2OUT_NEXT_REASS;
1894                   goto trace0;
1895                 }
1896             }
1897
1898           key0.addr = ip0->src_address;
1899           key0.port = udp0->src_port;
1900           key0.protocol = proto0;
1901           key0.fib_index = rx_fib_index0;
1902
1903           kv0.key = key0.as_u64;
1904
1905           if (clib_bihash_search_8_8 (&sm->per_thread_data[thread_index].in2out,
1906                                       &kv0, &value0))
1907             {
1908               if (is_slow_path)
1909                 {
1910                   if (PREDICT_FALSE(snat_not_translate(sm, node, sw_if_index0,
1911                       ip0, proto0, rx_fib_index0, thread_index)) && !is_output_feature)
1912                     goto trace0;
1913
1914                   next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0,
1915                                      &s0, node, next0, thread_index);
1916
1917                   if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
1918                     goto trace0;
1919                 }
1920               else
1921                 {
1922                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1923                   goto trace0;
1924                 }
1925             }
1926           else
1927             {
1928               if (PREDICT_FALSE (value0.value == ~0ULL))
1929                 {
1930                   if (is_slow_path)
1931                     {
1932                       s0 = snat_in2out_lb(sm, b0, ip0, rx_fib_index0,
1933                                           thread_index, now, vm, node);
1934                       if (!s0 && !sm->forwarding_enabled)
1935                         next0 = SNAT_IN2OUT_NEXT_DROP;
1936                       goto trace0;
1937                     }
1938                   else
1939                     {
1940                       next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1941                       goto trace0;
1942                     }
1943                 }
1944               else
1945                 {
1946                   s0 = pool_elt_at_index (
1947                     sm->per_thread_data[thread_index].sessions,
1948                     value0.value);
1949                 }
1950             }
1951
1952           b0->flags |= VNET_BUFFER_F_IS_NATED;
1953
1954           old_addr0 = ip0->src_address.as_u32;
1955           ip0->src_address = s0->out2in.addr;
1956           new_addr0 = ip0->src_address.as_u32;
1957           if (!is_output_feature)
1958             vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
1959
1960           sum0 = ip0->checksum;
1961           sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1962                                  ip4_header_t,
1963                                  src_address /* changed member */);
1964           ip0->checksum = ip_csum_fold (sum0);
1965
1966           if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
1967             {
1968               old_port0 = tcp0->src_port;
1969               tcp0->src_port = s0->out2in.port;
1970               new_port0 = tcp0->src_port;
1971
1972               sum0 = tcp0->checksum;
1973               sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1974                                      ip4_header_t,
1975                                      dst_address /* changed member */);
1976               sum0 = ip_csum_update (sum0, old_port0, new_port0,
1977                                      ip4_header_t /* cheat */,
1978                                      length /* changed member */);
1979               tcp0->checksum = ip_csum_fold(sum0);
1980             }
1981           else
1982             {
1983               old_port0 = udp0->src_port;
1984               udp0->src_port = s0->out2in.port;
1985               udp0->checksum = 0;
1986             }
1987
1988           /* Accounting */
1989           s0->last_heard = now;
1990           s0->total_pkts++;
1991           s0->total_bytes += vlib_buffer_length_in_chain (vm, b0);
1992           /* Per-user LRU list maintenance */
1993           clib_dlist_remove (sm->per_thread_data[thread_index].list_pool,
1994                              s0->per_user_index);
1995           clib_dlist_addtail (sm->per_thread_data[thread_index].list_pool,
1996                               s0->per_user_list_head_index,
1997                               s0->per_user_index);
1998
1999         trace0:
2000           if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
2001                             && (b0->flags & VLIB_BUFFER_IS_TRACED)))
2002             {
2003               snat_in2out_trace_t *t =
2004                  vlib_add_trace (vm, node, b0, sizeof (*t));
2005               t->is_slow_path = is_slow_path;
2006               t->sw_if_index = sw_if_index0;
2007               t->next_index = next0;
2008                   t->session_index = ~0;
2009               if (s0)
2010                 t->session_index = s0 - sm->per_thread_data[thread_index].sessions;
2011             }
2012
2013           pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
2014
2015           /* verify speculative enqueue, maybe switch current next frame */
2016           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
2017                                            to_next, n_left_to_next,
2018                                            bi0, next0);
2019         }
2020
2021       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2022     }
2023
2024   vlib_node_increment_counter (vm, stats_node_index,
2025                                SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
2026                                pkts_processed);
2027   return frame->n_vectors;
2028 }
2029
2030 static uword
2031 snat_in2out_fast_path_fn (vlib_main_t * vm,
2032                           vlib_node_runtime_t * node,
2033                           vlib_frame_t * frame)
2034 {
2035   return snat_in2out_node_fn_inline (vm, node, frame, 0 /* is_slow_path */, 0);
2036 }
2037
2038 VLIB_REGISTER_NODE (snat_in2out_node) = {
2039   .function = snat_in2out_fast_path_fn,
2040   .name = "nat44-in2out",
2041   .vector_size = sizeof (u32),
2042   .format_trace = format_snat_in2out_trace,
2043   .type = VLIB_NODE_TYPE_INTERNAL,
2044
2045   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
2046   .error_strings = snat_in2out_error_strings,
2047
2048   .runtime_data_bytes = sizeof (snat_runtime_t),
2049
2050   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
2051
2052   /* edit / add dispositions here */
2053   .next_nodes = {
2054     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
2055     [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
2056     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
2057     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
2058     [SNAT_IN2OUT_NEXT_REASS] = "nat44-in2out-reass",
2059   },
2060 };
2061
2062 VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_node, snat_in2out_fast_path_fn);
2063
2064 static uword
2065 snat_in2out_output_fast_path_fn (vlib_main_t * vm,
2066                                  vlib_node_runtime_t * node,
2067                                  vlib_frame_t * frame)
2068 {
2069   return snat_in2out_node_fn_inline (vm, node, frame, 0 /* is_slow_path */, 1);
2070 }
2071
2072 VLIB_REGISTER_NODE (snat_in2out_output_node) = {
2073   .function = snat_in2out_output_fast_path_fn,
2074   .name = "nat44-in2out-output",
2075   .vector_size = sizeof (u32),
2076   .format_trace = format_snat_in2out_trace,
2077   .type = VLIB_NODE_TYPE_INTERNAL,
2078
2079   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
2080   .error_strings = snat_in2out_error_strings,
2081
2082   .runtime_data_bytes = sizeof (snat_runtime_t),
2083
2084   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
2085
2086   /* edit / add dispositions here */
2087   .next_nodes = {
2088     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
2089     [SNAT_IN2OUT_NEXT_LOOKUP] = "interface-output",
2090     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-output-slowpath",
2091     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
2092     [SNAT_IN2OUT_NEXT_REASS] = "nat44-in2out-reass",
2093   },
2094 };
2095
2096 VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_output_node,
2097                               snat_in2out_output_fast_path_fn);
2098
2099 static uword
2100 snat_in2out_slow_path_fn (vlib_main_t * vm,
2101                           vlib_node_runtime_t * node,
2102                           vlib_frame_t * frame)
2103 {
2104   return snat_in2out_node_fn_inline (vm, node, frame, 1 /* is_slow_path */, 0);
2105 }
2106
2107 VLIB_REGISTER_NODE (snat_in2out_slowpath_node) = {
2108   .function = snat_in2out_slow_path_fn,
2109   .name = "nat44-in2out-slowpath",
2110   .vector_size = sizeof (u32),
2111   .format_trace = format_snat_in2out_trace,
2112   .type = VLIB_NODE_TYPE_INTERNAL,
2113
2114   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
2115   .error_strings = snat_in2out_error_strings,
2116
2117   .runtime_data_bytes = sizeof (snat_runtime_t),
2118
2119   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
2120
2121   /* edit / add dispositions here */
2122   .next_nodes = {
2123     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
2124     [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
2125     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
2126     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
2127     [SNAT_IN2OUT_NEXT_REASS] = "nat44-in2out-reass",
2128   },
2129 };
2130
2131 VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_slowpath_node,
2132                               snat_in2out_slow_path_fn);
2133
2134 static uword
2135 snat_in2out_output_slow_path_fn (vlib_main_t * vm,
2136                                  vlib_node_runtime_t * node,
2137                                  vlib_frame_t * frame)
2138 {
2139   return snat_in2out_node_fn_inline (vm, node, frame, 1 /* is_slow_path */, 1);
2140 }
2141
2142 VLIB_REGISTER_NODE (snat_in2out_output_slowpath_node) = {
2143   .function = snat_in2out_output_slow_path_fn,
2144   .name = "nat44-in2out-output-slowpath",
2145   .vector_size = sizeof (u32),
2146   .format_trace = format_snat_in2out_trace,
2147   .type = VLIB_NODE_TYPE_INTERNAL,
2148
2149   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
2150   .error_strings = snat_in2out_error_strings,
2151
2152   .runtime_data_bytes = sizeof (snat_runtime_t),
2153
2154   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
2155
2156   /* edit / add dispositions here */
2157   .next_nodes = {
2158     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
2159     [SNAT_IN2OUT_NEXT_LOOKUP] = "interface-output",
2160     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-output-slowpath",
2161     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
2162     [SNAT_IN2OUT_NEXT_REASS] = "nat44-in2out-reass",
2163   },
2164 };
2165
2166 VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_output_slowpath_node,
2167                               snat_in2out_output_slow_path_fn);
2168
2169 extern vnet_feature_arc_registration_t vnet_feat_arc_ip4_local;
2170
2171 static uword
2172 nat44_hairpinning_fn (vlib_main_t * vm,
2173                       vlib_node_runtime_t * node,
2174                       vlib_frame_t * frame)
2175 {
2176   u32 n_left_from, * from, * to_next;
2177   snat_in2out_next_t next_index;
2178   u32 pkts_processed = 0;
2179   snat_main_t * sm = &snat_main;
2180   vnet_feature_main_t *fm = &feature_main;
2181   u8 arc_index = vnet_feat_arc_ip4_local.feature_arc_index;
2182   vnet_feature_config_main_t *cm = &fm->feature_config_mains[arc_index];
2183
2184   from = vlib_frame_vector_args (frame);
2185   n_left_from = frame->n_vectors;
2186   next_index = node->cached_next_index;
2187
2188   while (n_left_from > 0)
2189     {
2190       u32 n_left_to_next;
2191
2192       vlib_get_next_frame (vm, node, next_index,
2193                            to_next, n_left_to_next);
2194
2195       while (n_left_from > 0 && n_left_to_next > 0)
2196         {
2197           u32 bi0;
2198           vlib_buffer_t * b0;
2199           u32 next0;
2200           ip4_header_t * ip0;
2201           u32 proto0;
2202           udp_header_t * udp0;
2203           tcp_header_t * tcp0;
2204
2205           /* speculatively enqueue b0 to the current next frame */
2206           bi0 = from[0];
2207           to_next[0] = bi0;
2208           from += 1;
2209           to_next += 1;
2210           n_left_from -= 1;
2211           n_left_to_next -= 1;
2212
2213           b0 = vlib_get_buffer (vm, bi0);
2214           ip0 = vlib_buffer_get_current (b0);
2215           udp0 = ip4_next_header (ip0);
2216           tcp0 = (tcp_header_t *) udp0;
2217
2218           proto0 = ip_proto_to_snat_proto (ip0->protocol);
2219
2220           vnet_get_config_data (&cm->config_main, &b0->current_config_index,
2221                                 &next0, 0);
2222
2223           if (snat_hairpinning (sm, b0, ip0, udp0, tcp0, proto0))
2224             next0 = SNAT_IN2OUT_NEXT_LOOKUP;
2225
2226           pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
2227
2228           /* verify speculative enqueue, maybe switch current next frame */
2229           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
2230                                            to_next, n_left_to_next,
2231                                            bi0, next0);
2232          }
2233
2234       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2235     }
2236
2237   vlib_node_increment_counter (vm, nat44_hairpinning_node.index,
2238                                SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
2239                                pkts_processed);
2240   return frame->n_vectors;
2241 }
2242
2243 VLIB_REGISTER_NODE (nat44_hairpinning_node) = {
2244   .function = nat44_hairpinning_fn,
2245   .name = "nat44-hairpinning",
2246   .vector_size = sizeof (u32),
2247   .type = VLIB_NODE_TYPE_INTERNAL,
2248   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
2249   .error_strings = snat_in2out_error_strings,
2250   .n_next_nodes = 2,
2251   .next_nodes = {
2252     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
2253     [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
2254   },
2255 };
2256
2257 VLIB_NODE_FUNCTION_MULTIARCH (nat44_hairpinning_node,
2258                               nat44_hairpinning_fn);
2259
2260 static inline void
2261 nat44_reass_hairpinning (snat_main_t *sm,
2262                          vlib_buffer_t * b0,
2263                          ip4_header_t * ip0,
2264                          u16 sport,
2265                          u16 dport,
2266                          u32 proto0)
2267 {
2268   snat_session_key_t key0, sm0;
2269   snat_session_t * s0;
2270   clib_bihash_kv_8_8_t kv0, value0;
2271   ip_csum_t sum0;
2272   u32 new_dst_addr0 = 0, old_dst_addr0, ti = 0, si;
2273   u16 new_dst_port0, old_dst_port0;
2274   udp_header_t * udp0;
2275   tcp_header_t * tcp0;
2276
2277   key0.addr = ip0->dst_address;
2278   key0.port = dport;
2279   key0.protocol = proto0;
2280   key0.fib_index = sm->outside_fib_index;
2281   kv0.key = key0.as_u64;
2282
2283   udp0 = ip4_next_header (ip0);
2284
2285   /* Check if destination is static mappings */
2286   if (!snat_static_mapping_match(sm, key0, &sm0, 1, 0, 0))
2287     {
2288       new_dst_addr0 = sm0.addr.as_u32;
2289       new_dst_port0 = sm0.port;
2290       vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
2291     }
2292   /* or active sessions */
2293   else
2294     {
2295       if (sm->num_workers > 1)
2296         ti = (clib_net_to_host_u16 (udp0->dst_port) - 1024) / sm->port_per_thread;
2297       else
2298         ti = sm->num_workers;
2299
2300       if (!clib_bihash_search_8_8 (&sm->per_thread_data[ti].out2in, &kv0, &value0))
2301         {
2302           si = value0.value;
2303           s0 = pool_elt_at_index (sm->per_thread_data[ti].sessions, si);
2304           new_dst_addr0 = s0->in2out.addr.as_u32;
2305           new_dst_port0 = s0->in2out.port;
2306           vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
2307         }
2308     }
2309
2310   /* Destination is behind the same NAT, use internal address and port */
2311   if (new_dst_addr0)
2312     {
2313       old_dst_addr0 = ip0->dst_address.as_u32;
2314       ip0->dst_address.as_u32 = new_dst_addr0;
2315       sum0 = ip0->checksum;
2316       sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
2317                              ip4_header_t, dst_address);
2318       ip0->checksum = ip_csum_fold (sum0);
2319
2320       old_dst_port0 = dport;
2321       if (PREDICT_TRUE(new_dst_port0 != old_dst_port0 &&
2322                        ip4_is_first_fragment (ip0)))
2323         {
2324           if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
2325             {
2326               tcp0 = ip4_next_header (ip0);
2327               tcp0->dst = new_dst_port0;
2328               sum0 = tcp0->checksum;
2329               sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
2330                                      ip4_header_t, dst_address);
2331               sum0 = ip_csum_update (sum0, old_dst_port0, new_dst_port0,
2332                                      ip4_header_t /* cheat */, length);
2333               tcp0->checksum = ip_csum_fold(sum0);
2334             }
2335           else
2336             {
2337               udp0->dst_port = new_dst_port0;
2338               udp0->checksum = 0;
2339             }
2340         }
2341       else
2342         {
2343           if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
2344             {
2345               tcp0 = ip4_next_header (ip0);
2346               sum0 = tcp0->checksum;
2347               sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
2348                                      ip4_header_t, dst_address);
2349               tcp0->checksum = ip_csum_fold(sum0);
2350             }
2351         }
2352     }
2353 }
2354
2355 static uword
2356 nat44_in2out_reass_node_fn (vlib_main_t * vm,
2357                             vlib_node_runtime_t * node,
2358                             vlib_frame_t * frame)
2359 {
2360   u32 n_left_from, *from, *to_next;
2361   snat_in2out_next_t next_index;
2362   u32 pkts_processed = 0;
2363   snat_main_t *sm = &snat_main;
2364   f64 now = vlib_time_now (vm);
2365   u32 thread_index = vlib_get_thread_index ();
2366   snat_main_per_thread_data_t *per_thread_data =
2367     &sm->per_thread_data[thread_index];
2368   u32 *fragments_to_drop = 0;
2369   u32 *fragments_to_loopback = 0;
2370
2371   from = vlib_frame_vector_args (frame);
2372   n_left_from = frame->n_vectors;
2373   next_index = node->cached_next_index;
2374
2375   while (n_left_from > 0)
2376     {
2377       u32 n_left_to_next;
2378
2379       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2380
2381       while (n_left_from > 0 && n_left_to_next > 0)
2382        {
2383           u32 bi0, sw_if_index0, proto0, rx_fib_index0, new_addr0, old_addr0;
2384           vlib_buffer_t *b0;
2385           u32 next0;
2386           u8 cached0 = 0;
2387           ip4_header_t *ip0;
2388           nat_reass_ip4_t *reass0;
2389           udp_header_t * udp0;
2390           tcp_header_t * tcp0;
2391           snat_session_key_t key0;
2392           clib_bihash_kv_8_8_t kv0, value0;
2393           snat_session_t * s0 = 0;
2394           u16 old_port0, new_port0;
2395           ip_csum_t sum0;
2396
2397           /* speculatively enqueue b0 to the current next frame */
2398           bi0 = from[0];
2399           to_next[0] = bi0;
2400           from += 1;
2401           to_next += 1;
2402           n_left_from -= 1;
2403           n_left_to_next -= 1;
2404
2405           b0 = vlib_get_buffer (vm, bi0);
2406           next0 = SNAT_IN2OUT_NEXT_LOOKUP;
2407
2408           sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
2409           rx_fib_index0 = fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
2410                                                                sw_if_index0);
2411
2412           if (PREDICT_FALSE (nat_reass_is_drop_frag(0)))
2413             {
2414               next0 = SNAT_IN2OUT_NEXT_DROP;
2415               b0->error = node->errors[SNAT_IN2OUT_ERROR_DROP_FRAGMENT];
2416               goto trace0;
2417             }
2418
2419           ip0 = (ip4_header_t *) vlib_buffer_get_current (b0);
2420           udp0 = ip4_next_header (ip0);
2421           tcp0 = (tcp_header_t *) udp0;
2422           proto0 = ip_proto_to_snat_proto (ip0->protocol);
2423
2424           reass0 = nat_ip4_reass_find_or_create (ip0->src_address,
2425                                                  ip0->dst_address,
2426                                                  ip0->fragment_id,
2427                                                  ip0->protocol,
2428                                                  1,
2429                                                  &fragments_to_drop);
2430
2431           if (PREDICT_FALSE (!reass0))
2432             {
2433               next0 = SNAT_IN2OUT_NEXT_DROP;
2434               b0->error = node->errors[SNAT_IN2OUT_ERROR_MAX_REASS];
2435               goto trace0;
2436             }
2437
2438           if (PREDICT_FALSE (ip4_is_first_fragment (ip0)))
2439             {
2440               key0.addr = ip0->src_address;
2441               key0.port = udp0->src_port;
2442               key0.protocol = proto0;
2443               key0.fib_index = rx_fib_index0;
2444               kv0.key = key0.as_u64;
2445
2446               if (clib_bihash_search_8_8 (&per_thread_data->in2out, &kv0, &value0))
2447                 {
2448                   if (PREDICT_FALSE(snat_not_translate(sm, node, sw_if_index0,
2449                       ip0, proto0, rx_fib_index0, thread_index)))
2450                     goto trace0;
2451
2452                   next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0,
2453                                      &s0, node, next0, thread_index);
2454
2455                   if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
2456                     goto trace0;
2457
2458                   reass0->sess_index = s0 - per_thread_data->sessions;
2459                 }
2460               else
2461                 {
2462                   s0 = pool_elt_at_index (per_thread_data->sessions,
2463                                           value0.value);
2464                   reass0->sess_index = value0.value;
2465                 }
2466               nat_ip4_reass_get_frags (reass0, &fragments_to_loopback);
2467             }
2468           else
2469             {
2470               if (PREDICT_FALSE (reass0->sess_index == (u32) ~0))
2471                 {
2472                   if (nat_ip4_reass_add_fragment (reass0, bi0))
2473                     {
2474                       b0->error = node->errors[SNAT_IN2OUT_ERROR_MAX_FRAG];
2475                       next0 = SNAT_IN2OUT_NEXT_DROP;
2476                       goto trace0;
2477                     }
2478                   cached0 = 1;
2479                   goto trace0;
2480                 }
2481               s0 = pool_elt_at_index (per_thread_data->sessions,
2482                                       reass0->sess_index);
2483             }
2484
2485           old_addr0 = ip0->src_address.as_u32;
2486           ip0->src_address = s0->out2in.addr;
2487           new_addr0 = ip0->src_address.as_u32;
2488           vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
2489
2490           sum0 = ip0->checksum;
2491           sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
2492                                  ip4_header_t,
2493                                  src_address /* changed member */);
2494           ip0->checksum = ip_csum_fold (sum0);
2495
2496           if (PREDICT_FALSE (ip4_is_first_fragment (ip0)))
2497             {
2498               if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
2499                 {
2500                   old_port0 = tcp0->src_port;
2501                   tcp0->src_port = s0->out2in.port;
2502                   new_port0 = tcp0->src_port;
2503
2504                   sum0 = tcp0->checksum;
2505                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
2506                                          ip4_header_t,
2507                                          dst_address /* changed member */);
2508                   sum0 = ip_csum_update (sum0, old_port0, new_port0,
2509                                          ip4_header_t /* cheat */,
2510                                          length /* changed member */);
2511                   tcp0->checksum = ip_csum_fold(sum0);
2512                 }
2513               else
2514                 {
2515                   old_port0 = udp0->src_port;
2516                   udp0->src_port = s0->out2in.port;
2517                   udp0->checksum = 0;
2518                 }
2519             }
2520
2521           /* Hairpinning */
2522           nat44_reass_hairpinning (sm, b0, ip0, s0->out2in.port,
2523                                    s0->ext_host_port, proto0);
2524
2525           /* Accounting */
2526           s0->last_heard = now;
2527           s0->total_pkts++;
2528           s0->total_bytes += vlib_buffer_length_in_chain (vm, b0);
2529           /* Per-user LRU list maintenance */
2530           clib_dlist_remove (sm->per_thread_data[thread_index].list_pool,
2531                              s0->per_user_index);
2532           clib_dlist_addtail (sm->per_thread_data[thread_index].list_pool,
2533                               s0->per_user_list_head_index,
2534                               s0->per_user_index);
2535
2536         trace0:
2537           if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
2538                             && (b0->flags & VLIB_BUFFER_IS_TRACED)))
2539             {
2540               nat44_in2out_reass_trace_t *t =
2541                  vlib_add_trace (vm, node, b0, sizeof (*t));
2542               t->cached = cached0;
2543               t->sw_if_index = sw_if_index0;
2544               t->next_index = next0;
2545             }
2546
2547           if (cached0)
2548             {
2549               n_left_to_next++;
2550               to_next--;
2551             }
2552           else
2553             {
2554               pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
2555
2556               /* verify speculative enqueue, maybe switch current next frame */
2557               vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
2558                                                to_next, n_left_to_next,
2559                                                bi0, next0);
2560             }
2561
2562           if (n_left_from == 0 && vec_len (fragments_to_loopback))
2563             {
2564               from = vlib_frame_vector_args (frame);
2565               u32 len = vec_len (fragments_to_loopback);
2566               if (len <= VLIB_FRAME_SIZE)
2567                 {
2568                   clib_memcpy (from, fragments_to_loopback, sizeof (u32) * len);
2569                   n_left_from = len;
2570                   vec_reset_length (fragments_to_loopback);
2571                 }
2572               else
2573                 {
2574                   clib_memcpy (from,
2575                                fragments_to_loopback + (len - VLIB_FRAME_SIZE),
2576                                sizeof (u32) * VLIB_FRAME_SIZE);
2577                   n_left_from = VLIB_FRAME_SIZE;
2578                   _vec_len (fragments_to_loopback) = len - VLIB_FRAME_SIZE;
2579                 }
2580             }
2581        }
2582
2583       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2584     }
2585
2586   vlib_node_increment_counter (vm, nat44_in2out_reass_node.index,
2587                                SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
2588                                pkts_processed);
2589
2590   nat_send_all_to_node (vm, fragments_to_drop, node,
2591                         &node->errors[SNAT_IN2OUT_ERROR_DROP_FRAGMENT],
2592                         SNAT_IN2OUT_NEXT_DROP);
2593
2594   vec_free (fragments_to_drop);
2595   vec_free (fragments_to_loopback);
2596   return frame->n_vectors;
2597 }
2598
2599 VLIB_REGISTER_NODE (nat44_in2out_reass_node) = {
2600   .function = nat44_in2out_reass_node_fn,
2601   .name = "nat44-in2out-reass",
2602   .vector_size = sizeof (u32),
2603   .format_trace = format_nat44_in2out_reass_trace,
2604   .type = VLIB_NODE_TYPE_INTERNAL,
2605
2606   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
2607   .error_strings = snat_in2out_error_strings,
2608
2609   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
2610   .next_nodes = {
2611     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
2612     [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
2613     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
2614     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
2615     [SNAT_IN2OUT_NEXT_REASS] = "nat44-in2out-reass",
2616   },
2617 };
2618
2619 VLIB_NODE_FUNCTION_MULTIARCH (nat44_in2out_reass_node,
2620                               nat44_in2out_reass_node_fn);
2621
2622 /**************************/
2623 /*** deterministic mode ***/
2624 /**************************/
2625 static uword
2626 snat_det_in2out_node_fn (vlib_main_t * vm,
2627                          vlib_node_runtime_t * node,
2628                          vlib_frame_t * frame)
2629 {
2630   u32 n_left_from, * from, * to_next;
2631   snat_in2out_next_t next_index;
2632   u32 pkts_processed = 0;
2633   snat_main_t * sm = &snat_main;
2634   u32 now = (u32) vlib_time_now (vm);
2635   u32 thread_index = vlib_get_thread_index ();
2636
2637   from = vlib_frame_vector_args (frame);
2638   n_left_from = frame->n_vectors;
2639   next_index = node->cached_next_index;
2640
2641   while (n_left_from > 0)
2642     {
2643       u32 n_left_to_next;
2644
2645       vlib_get_next_frame (vm, node, next_index,
2646                            to_next, n_left_to_next);
2647
2648       while (n_left_from >= 4 && n_left_to_next >= 2)
2649         {
2650           u32 bi0, bi1;
2651           vlib_buffer_t * b0, * b1;
2652           u32 next0, next1;
2653           u32 sw_if_index0, sw_if_index1;
2654           ip4_header_t * ip0, * ip1;
2655           ip_csum_t sum0, sum1;
2656           ip4_address_t new_addr0, old_addr0, new_addr1, old_addr1;
2657           u16 old_port0, new_port0, lo_port0, i0;
2658           u16 old_port1, new_port1, lo_port1, i1;
2659           udp_header_t * udp0, * udp1;
2660           tcp_header_t * tcp0, * tcp1;
2661           u32 proto0, proto1;
2662           snat_det_out_key_t key0, key1;
2663           snat_det_map_t * dm0, * dm1;
2664           snat_det_session_t * ses0 = 0, * ses1 = 0;
2665           u32 rx_fib_index0, rx_fib_index1;
2666           icmp46_header_t * icmp0, * icmp1;
2667
2668           /* Prefetch next iteration. */
2669           {
2670             vlib_buffer_t * p2, * p3;
2671
2672             p2 = vlib_get_buffer (vm, from[2]);
2673             p3 = vlib_get_buffer (vm, from[3]);
2674
2675             vlib_prefetch_buffer_header (p2, LOAD);
2676             vlib_prefetch_buffer_header (p3, LOAD);
2677
2678             CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE);
2679             CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE);
2680           }
2681
2682           /* speculatively enqueue b0 and b1 to the current next frame */
2683           to_next[0] = bi0 = from[0];
2684           to_next[1] = bi1 = from[1];
2685           from += 2;
2686           to_next += 2;
2687           n_left_from -= 2;
2688           n_left_to_next -= 2;
2689
2690           b0 = vlib_get_buffer (vm, bi0);
2691           b1 = vlib_get_buffer (vm, bi1);
2692
2693           next0 = SNAT_IN2OUT_NEXT_LOOKUP;
2694           next1 = SNAT_IN2OUT_NEXT_LOOKUP;
2695
2696           ip0 = vlib_buffer_get_current (b0);
2697           udp0 = ip4_next_header (ip0);
2698           tcp0 = (tcp_header_t *) udp0;
2699
2700           sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
2701
2702           if (PREDICT_FALSE(ip0->ttl == 1))
2703             {
2704               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
2705               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
2706                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
2707                                            0);
2708               next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
2709               goto trace0;
2710             }
2711
2712           proto0 = ip_proto_to_snat_proto (ip0->protocol);
2713
2714           if (PREDICT_FALSE(proto0 == SNAT_PROTOCOL_ICMP))
2715             {
2716               rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index(sw_if_index0);
2717               icmp0 = (icmp46_header_t *) udp0;
2718
2719               next0 = icmp_in2out(sm, b0, ip0, icmp0, sw_if_index0,
2720                                   rx_fib_index0, node, next0, thread_index,
2721                                   &ses0, &dm0);
2722               goto trace0;
2723             }
2724
2725           dm0 = snat_det_map_by_user(sm, &ip0->src_address);
2726           if (PREDICT_FALSE(!dm0))
2727             {
2728               clib_warning("no match for internal host %U",
2729                            format_ip4_address, &ip0->src_address);
2730               next0 = SNAT_IN2OUT_NEXT_DROP;
2731               b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
2732               goto trace0;
2733             }
2734
2735           snat_det_forward(dm0, &ip0->src_address, &new_addr0, &lo_port0);
2736
2737           key0.ext_host_addr = ip0->dst_address;
2738           key0.ext_host_port = tcp0->dst;
2739
2740           ses0 = snat_det_find_ses_by_in(dm0, &ip0->src_address, tcp0->src, key0);
2741           if (PREDICT_FALSE(!ses0))
2742             {
2743               for (i0 = 0; i0 < dm0->ports_per_host; i0++)
2744                 {
2745                   key0.out_port = clib_host_to_net_u16 (lo_port0 +
2746                     ((i0 + clib_net_to_host_u16 (tcp0->src)) % dm0->ports_per_host));
2747
2748                   if (snat_det_get_ses_by_out (dm0, &ip0->src_address, key0.as_u64))
2749                     continue;
2750
2751                   ses0 = snat_det_ses_create(dm0, &ip0->src_address, tcp0->src, &key0);
2752                   break;
2753                 }
2754               if (PREDICT_FALSE(!ses0))
2755                 {
2756                   /* too many sessions for user, send ICMP error packet */
2757
2758                   vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
2759                   icmp4_error_set_vnet_buffer (b0, ICMP4_destination_unreachable,
2760                                                ICMP4_destination_unreachable_destination_unreachable_host,
2761                                                0);
2762                   next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
2763                   goto trace0;
2764                 }
2765             }
2766
2767           new_port0 = ses0->out.out_port;
2768
2769           old_addr0.as_u32 = ip0->src_address.as_u32;
2770           ip0->src_address.as_u32 = new_addr0.as_u32;
2771           vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm->outside_fib_index;
2772
2773           sum0 = ip0->checksum;
2774           sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32,
2775                                  ip4_header_t,
2776                                  src_address /* changed member */);
2777           ip0->checksum = ip_csum_fold (sum0);
2778
2779           if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
2780             {
2781               if (tcp0->flags & TCP_FLAG_SYN)
2782                 ses0->state = SNAT_SESSION_TCP_SYN_SENT;
2783               else if (tcp0->flags & TCP_FLAG_ACK && ses0->state == SNAT_SESSION_TCP_SYN_SENT)
2784                 ses0->state = SNAT_SESSION_TCP_ESTABLISHED;
2785               else if (tcp0->flags & TCP_FLAG_FIN && ses0->state == SNAT_SESSION_TCP_ESTABLISHED)
2786                 ses0->state = SNAT_SESSION_TCP_FIN_WAIT;
2787               else if (tcp0->flags & TCP_FLAG_ACK && ses0->state == SNAT_SESSION_TCP_FIN_WAIT)
2788                 snat_det_ses_close(dm0, ses0);
2789               else if (tcp0->flags & TCP_FLAG_FIN && ses0->state == SNAT_SESSION_TCP_CLOSE_WAIT)
2790                 ses0->state = SNAT_SESSION_TCP_LAST_ACK;
2791               else if (tcp0->flags == 0 && ses0->state == SNAT_SESSION_UNKNOWN)
2792                 ses0->state = SNAT_SESSION_TCP_ESTABLISHED;
2793
2794               old_port0 = tcp0->src;
2795               tcp0->src = new_port0;
2796
2797               sum0 = tcp0->checksum;
2798               sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32,
2799                                      ip4_header_t,
2800                                      dst_address /* changed member */);
2801               sum0 = ip_csum_update (sum0, old_port0, new_port0,
2802                                      ip4_header_t /* cheat */,
2803                                      length /* changed member */);
2804               tcp0->checksum = ip_csum_fold(sum0);
2805             }
2806           else
2807             {
2808               ses0->state = SNAT_SESSION_UDP_ACTIVE;
2809               old_port0 = udp0->src_port;
2810               udp0->src_port = new_port0;
2811               udp0->checksum = 0;
2812             }
2813
2814           switch(ses0->state)
2815             {
2816             case SNAT_SESSION_UDP_ACTIVE:
2817                 ses0->expire = now + sm->udp_timeout;
2818                 break;
2819             case SNAT_SESSION_TCP_SYN_SENT:
2820             case SNAT_SESSION_TCP_FIN_WAIT:
2821             case SNAT_SESSION_TCP_CLOSE_WAIT:
2822             case SNAT_SESSION_TCP_LAST_ACK:
2823                 ses0->expire = now + sm->tcp_transitory_timeout;
2824                 break;
2825             case SNAT_SESSION_TCP_ESTABLISHED:
2826                 ses0->expire = now + sm->tcp_established_timeout;
2827                 break;
2828             }
2829
2830         trace0:
2831           if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
2832                             && (b0->flags & VLIB_BUFFER_IS_TRACED)))
2833             {
2834               snat_in2out_trace_t *t =
2835                  vlib_add_trace (vm, node, b0, sizeof (*t));
2836               t->is_slow_path = 0;
2837               t->sw_if_index = sw_if_index0;
2838               t->next_index = next0;
2839               t->session_index = ~0;
2840               if (ses0)
2841                 t->session_index = ses0 - dm0->sessions;
2842             }
2843
2844           pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
2845
2846           ip1 = vlib_buffer_get_current (b1);
2847           udp1 = ip4_next_header (ip1);
2848           tcp1 = (tcp_header_t *) udp1;
2849
2850           sw_if_index1 = vnet_buffer(b1)->sw_if_index[VLIB_RX];
2851
2852           if (PREDICT_FALSE(ip1->ttl == 1))
2853             {
2854               vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
2855               icmp4_error_set_vnet_buffer (b1, ICMP4_time_exceeded,
2856                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
2857                                            0);
2858               next1 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
2859               goto trace1;
2860             }
2861
2862           proto1 = ip_proto_to_snat_proto (ip1->protocol);
2863
2864           if (PREDICT_FALSE(proto1 == SNAT_PROTOCOL_ICMP))
2865             {
2866               rx_fib_index1 = ip4_fib_table_get_index_for_sw_if_index(sw_if_index1);
2867               icmp1 = (icmp46_header_t *) udp1;
2868
2869               next1 = icmp_in2out(sm, b1, ip1, icmp1, sw_if_index1,
2870                                   rx_fib_index1, node, next1, thread_index,
2871                                   &ses1, &dm1);
2872               goto trace1;
2873             }
2874
2875           dm1 = snat_det_map_by_user(sm, &ip1->src_address);
2876           if (PREDICT_FALSE(!dm1))
2877             {
2878               clib_warning("no match for internal host %U",
2879                            format_ip4_address, &ip0->src_address);
2880               next1 = SNAT_IN2OUT_NEXT_DROP;
2881               b1->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
2882               goto trace1;
2883             }
2884
2885           snat_det_forward(dm1, &ip1->src_address, &new_addr1, &lo_port1);
2886
2887           key1.ext_host_addr = ip1->dst_address;
2888           key1.ext_host_port = tcp1->dst;
2889
2890           ses1 = snat_det_find_ses_by_in(dm1, &ip1->src_address, tcp1->src, key1);
2891           if (PREDICT_FALSE(!ses1))
2892             {
2893               for (i1 = 0; i1 < dm1->ports_per_host; i1++)
2894                 {
2895                   key1.out_port = clib_host_to_net_u16 (lo_port1 +
2896                     ((i1 + clib_net_to_host_u16 (tcp1->src)) % dm1->ports_per_host));
2897
2898                   if (snat_det_get_ses_by_out (dm1, &ip1->src_address, key1.as_u64))
2899                     continue;
2900
2901                   ses1 = snat_det_ses_create(dm1, &ip1->src_address, tcp1->src, &key1);
2902                   break;
2903                 }
2904               if (PREDICT_FALSE(!ses1))
2905                 {
2906                   /* too many sessions for user, send ICMP error packet */
2907
2908                   vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
2909                   icmp4_error_set_vnet_buffer (b1, ICMP4_destination_unreachable,
2910                                                ICMP4_destination_unreachable_destination_unreachable_host,
2911                                                0);
2912                   next1 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
2913                   goto trace1;
2914                 }
2915             }
2916
2917           new_port1 = ses1->out.out_port;
2918
2919           old_addr1.as_u32 = ip1->src_address.as_u32;
2920           ip1->src_address.as_u32 = new_addr1.as_u32;
2921           vnet_buffer(b1)->sw_if_index[VLIB_TX] = sm->outside_fib_index;
2922
2923           sum1 = ip1->checksum;
2924           sum1 = ip_csum_update (sum1, old_addr1.as_u32, new_addr1.as_u32,
2925                                  ip4_header_t,
2926                                  src_address /* changed member */);
2927           ip1->checksum = ip_csum_fold (sum1);
2928
2929           if (PREDICT_TRUE(proto1 == SNAT_PROTOCOL_TCP))
2930             {
2931               if (tcp1->flags & TCP_FLAG_SYN)
2932                 ses1->state = SNAT_SESSION_TCP_SYN_SENT;
2933               else if (tcp1->flags & TCP_FLAG_ACK && ses1->state == SNAT_SESSION_TCP_SYN_SENT)
2934                 ses1->state = SNAT_SESSION_TCP_ESTABLISHED;
2935               else if (tcp1->flags & TCP_FLAG_FIN && ses1->state == SNAT_SESSION_TCP_ESTABLISHED)
2936                 ses1->state = SNAT_SESSION_TCP_FIN_WAIT;
2937               else if (tcp1->flags & TCP_FLAG_ACK && ses1->state == SNAT_SESSION_TCP_FIN_WAIT)
2938                 snat_det_ses_close(dm1, ses1);
2939               else if (tcp1->flags & TCP_FLAG_FIN && ses1->state == SNAT_SESSION_TCP_CLOSE_WAIT)
2940                 ses1->state = SNAT_SESSION_TCP_LAST_ACK;
2941               else if (tcp1->flags == 0 && ses1->state == SNAT_SESSION_UNKNOWN)
2942                 ses1->state = SNAT_SESSION_TCP_ESTABLISHED;
2943
2944               old_port1 = tcp1->src;
2945               tcp1->src = new_port1;
2946
2947               sum1 = tcp1->checksum;
2948               sum1 = ip_csum_update (sum1, old_addr1.as_u32, new_addr1.as_u32,
2949                                      ip4_header_t,
2950                                      dst_address /* changed member */);
2951               sum1 = ip_csum_update (sum1, old_port1, new_port1,
2952                                      ip4_header_t /* cheat */,
2953                                      length /* changed member */);
2954               tcp1->checksum = ip_csum_fold(sum1);
2955             }
2956           else
2957             {
2958               ses1->state = SNAT_SESSION_UDP_ACTIVE;
2959               old_port1 = udp1->src_port;
2960               udp1->src_port = new_port1;
2961               udp1->checksum = 0;
2962             }
2963
2964           switch(ses1->state)
2965             {
2966             case SNAT_SESSION_UDP_ACTIVE:
2967                 ses1->expire = now + sm->udp_timeout;
2968                 break;
2969             case SNAT_SESSION_TCP_SYN_SENT:
2970             case SNAT_SESSION_TCP_FIN_WAIT:
2971             case SNAT_SESSION_TCP_CLOSE_WAIT:
2972             case SNAT_SESSION_TCP_LAST_ACK:
2973                 ses1->expire = now + sm->tcp_transitory_timeout;
2974                 break;
2975             case SNAT_SESSION_TCP_ESTABLISHED:
2976                 ses1->expire = now + sm->tcp_established_timeout;
2977                 break;
2978             }
2979
2980         trace1:
2981           if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
2982                             && (b1->flags & VLIB_BUFFER_IS_TRACED)))
2983             {
2984               snat_in2out_trace_t *t =
2985                  vlib_add_trace (vm, node, b1, sizeof (*t));
2986               t->is_slow_path = 0;
2987               t->sw_if_index = sw_if_index1;
2988               t->next_index = next1;
2989               t->session_index = ~0;
2990               if (ses1)
2991                 t->session_index = ses1 - dm1->sessions;
2992             }
2993
2994           pkts_processed += next1 != SNAT_IN2OUT_NEXT_DROP;
2995
2996           /* verify speculative enqueues, maybe switch current next frame */
2997           vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
2998                                            to_next, n_left_to_next,
2999                                            bi0, bi1, next0, next1);
3000          }
3001
3002       while (n_left_from > 0 && n_left_to_next > 0)
3003         {
3004           u32 bi0;
3005           vlib_buffer_t * b0;
3006           u32 next0;
3007           u32 sw_if_index0;
3008           ip4_header_t * ip0;
3009           ip_csum_t sum0;
3010           ip4_address_t new_addr0, old_addr0;
3011           u16 old_port0, new_port0, lo_port0, i0;
3012           udp_header_t * udp0;
3013           tcp_header_t * tcp0;
3014           u32 proto0;
3015           snat_det_out_key_t key0;
3016           snat_det_map_t * dm0;
3017           snat_det_session_t * ses0 = 0;
3018           u32 rx_fib_index0;
3019           icmp46_header_t * icmp0;
3020
3021           /* speculatively enqueue b0 to the current next frame */
3022           bi0 = from[0];
3023           to_next[0] = bi0;
3024           from += 1;
3025           to_next += 1;
3026           n_left_from -= 1;
3027           n_left_to_next -= 1;
3028
3029           b0 = vlib_get_buffer (vm, bi0);
3030           next0 = SNAT_IN2OUT_NEXT_LOOKUP;
3031
3032           ip0 = vlib_buffer_get_current (b0);
3033           udp0 = ip4_next_header (ip0);
3034           tcp0 = (tcp_header_t *) udp0;
3035
3036           sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
3037
3038           if (PREDICT_FALSE(ip0->ttl == 1))
3039             {
3040               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
3041               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
3042                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
3043                                            0);
3044               next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
3045               goto trace00;
3046             }
3047
3048           proto0 = ip_proto_to_snat_proto (ip0->protocol);
3049
3050           if (PREDICT_FALSE(proto0 == SNAT_PROTOCOL_ICMP))
3051             {
3052               rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index(sw_if_index0);
3053               icmp0 = (icmp46_header_t *) udp0;
3054
3055               next0 = icmp_in2out(sm, b0, ip0, icmp0, sw_if_index0,
3056                                   rx_fib_index0, node, next0, thread_index,
3057                                   &ses0, &dm0);
3058               goto trace00;
3059             }
3060
3061           dm0 = snat_det_map_by_user(sm, &ip0->src_address);
3062           if (PREDICT_FALSE(!dm0))
3063             {
3064               clib_warning("no match for internal host %U",
3065                            format_ip4_address, &ip0->src_address);
3066               next0 = SNAT_IN2OUT_NEXT_DROP;
3067               b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
3068               goto trace00;
3069             }
3070
3071           snat_det_forward(dm0, &ip0->src_address, &new_addr0, &lo_port0);
3072
3073           key0.ext_host_addr = ip0->dst_address;
3074           key0.ext_host_port = tcp0->dst;
3075
3076           ses0 = snat_det_find_ses_by_in(dm0, &ip0->src_address, tcp0->src, key0);
3077           if (PREDICT_FALSE(!ses0))
3078             {
3079               for (i0 = 0; i0 < dm0->ports_per_host; i0++)
3080                 {
3081                   key0.out_port = clib_host_to_net_u16 (lo_port0 +
3082                     ((i0 + clib_net_to_host_u16 (tcp0->src)) % dm0->ports_per_host));
3083
3084                   if (snat_det_get_ses_by_out (dm0, &ip0->src_address, key0.as_u64))
3085                     continue;
3086
3087                   ses0 = snat_det_ses_create(dm0, &ip0->src_address, tcp0->src, &key0);
3088                   break;
3089                 }
3090               if (PREDICT_FALSE(!ses0))
3091                 {
3092                   /* too many sessions for user, send ICMP error packet */
3093
3094                   vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
3095                   icmp4_error_set_vnet_buffer (b0, ICMP4_destination_unreachable,
3096                                                ICMP4_destination_unreachable_destination_unreachable_host,
3097                                                0);
3098                   next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
3099                   goto trace00;
3100                 }
3101             }
3102
3103           new_port0 = ses0->out.out_port;
3104
3105           old_addr0.as_u32 = ip0->src_address.as_u32;
3106           ip0->src_address.as_u32 = new_addr0.as_u32;
3107           vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm->outside_fib_index;
3108
3109           sum0 = ip0->checksum;
3110           sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32,
3111                                  ip4_header_t,
3112                                  src_address /* changed member */);
3113           ip0->checksum = ip_csum_fold (sum0);
3114
3115           if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
3116             {
3117               if (tcp0->flags & TCP_FLAG_SYN)
3118                 ses0->state = SNAT_SESSION_TCP_SYN_SENT;
3119               else if (tcp0->flags & TCP_FLAG_ACK && ses0->state == SNAT_SESSION_TCP_SYN_SENT)
3120                 ses0->state = SNAT_SESSION_TCP_ESTABLISHED;
3121               else if (tcp0->flags & TCP_FLAG_FIN && ses0->state == SNAT_SESSION_TCP_ESTABLISHED)
3122                 ses0->state = SNAT_SESSION_TCP_FIN_WAIT;
3123               else if (tcp0->flags & TCP_FLAG_ACK && ses0->state == SNAT_SESSION_TCP_FIN_WAIT)
3124                 snat_det_ses_close(dm0, ses0);
3125               else if (tcp0->flags & TCP_FLAG_FIN && ses0->state == SNAT_SESSION_TCP_CLOSE_WAIT)
3126                 ses0->state = SNAT_SESSION_TCP_LAST_ACK;
3127               else if (tcp0->flags == 0 && ses0->state == SNAT_SESSION_UNKNOWN)
3128                 ses0->state = SNAT_SESSION_TCP_ESTABLISHED;
3129
3130               old_port0 = tcp0->src;
3131               tcp0->src = new_port0;
3132
3133               sum0 = tcp0->checksum;
3134               sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32,
3135                                      ip4_header_t,
3136                                      dst_address /* changed member */);
3137               sum0 = ip_csum_update (sum0, old_port0, new_port0,
3138                                      ip4_header_t /* cheat */,
3139                                      length /* changed member */);
3140               tcp0->checksum = ip_csum_fold(sum0);
3141             }
3142           else
3143             {
3144               ses0->state = SNAT_SESSION_UDP_ACTIVE;
3145               old_port0 = udp0->src_port;
3146               udp0->src_port = new_port0;
3147               udp0->checksum = 0;
3148             }
3149
3150           switch(ses0->state)
3151             {
3152             case SNAT_SESSION_UDP_ACTIVE:
3153                 ses0->expire = now + sm->udp_timeout;
3154                 break;
3155             case SNAT_SESSION_TCP_SYN_SENT:
3156             case SNAT_SESSION_TCP_FIN_WAIT:
3157             case SNAT_SESSION_TCP_CLOSE_WAIT:
3158             case SNAT_SESSION_TCP_LAST_ACK:
3159                 ses0->expire = now + sm->tcp_transitory_timeout;
3160                 break;
3161             case SNAT_SESSION_TCP_ESTABLISHED:
3162                 ses0->expire = now + sm->tcp_established_timeout;
3163                 break;
3164             }
3165
3166         trace00:
3167           if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
3168                             && (b0->flags & VLIB_BUFFER_IS_TRACED)))
3169             {
3170               snat_in2out_trace_t *t =
3171                  vlib_add_trace (vm, node, b0, sizeof (*t));
3172               t->is_slow_path = 0;
3173               t->sw_if_index = sw_if_index0;
3174               t->next_index = next0;
3175               t->session_index = ~0;
3176               if (ses0)
3177                 t->session_index = ses0 - dm0->sessions;
3178             }
3179
3180           pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
3181
3182           /* verify speculative enqueue, maybe switch current next frame */
3183           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
3184                                            to_next, n_left_to_next,
3185                                            bi0, next0);
3186         }
3187
3188       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
3189     }
3190
3191   vlib_node_increment_counter (vm, snat_det_in2out_node.index,
3192                                SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
3193                                pkts_processed);
3194   return frame->n_vectors;
3195 }
3196
3197 VLIB_REGISTER_NODE (snat_det_in2out_node) = {
3198   .function = snat_det_in2out_node_fn,
3199   .name = "nat44-det-in2out",
3200   .vector_size = sizeof (u32),
3201   .format_trace = format_snat_in2out_trace,
3202   .type = VLIB_NODE_TYPE_INTERNAL,
3203
3204   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
3205   .error_strings = snat_in2out_error_strings,
3206
3207   .runtime_data_bytes = sizeof (snat_runtime_t),
3208
3209   .n_next_nodes = 3,
3210
3211   /* edit / add dispositions here */
3212   .next_nodes = {
3213     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
3214     [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
3215     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
3216   },
3217 };
3218
3219 VLIB_NODE_FUNCTION_MULTIARCH (snat_det_in2out_node, snat_det_in2out_node_fn);
3220
3221 /**
3222  * Get address and port values to be used for ICMP packet translation
3223  * and create session if needed
3224  *
3225  * @param[in,out] sm             NAT main
3226  * @param[in,out] node           NAT node runtime
3227  * @param[in] thread_index       thread index
3228  * @param[in,out] b0             buffer containing packet to be translated
3229  * @param[out] p_proto           protocol used for matching
3230  * @param[out] p_value           address and port after NAT translation
3231  * @param[out] p_dont_translate  if packet should not be translated
3232  * @param d                      optional parameter
3233  * @param e                      optional parameter
3234  */
3235 u32 icmp_match_in2out_det(snat_main_t *sm, vlib_node_runtime_t *node,
3236                           u32 thread_index, vlib_buffer_t *b0,
3237                           ip4_header_t *ip0, u8 *p_proto,
3238                           snat_session_key_t *p_value,
3239                           u8 *p_dont_translate, void *d, void *e)
3240 {
3241   icmp46_header_t *icmp0;
3242   u32 sw_if_index0;
3243   u32 rx_fib_index0;
3244   u8 protocol;
3245   snat_det_out_key_t key0;
3246   u8 dont_translate = 0;
3247   u32 next0 = ~0;
3248   icmp_echo_header_t *echo0, *inner_echo0 = 0;
3249   ip4_header_t *inner_ip0;
3250   void *l4_header = 0;
3251   icmp46_header_t *inner_icmp0;
3252   snat_det_map_t * dm0 = 0;
3253   ip4_address_t new_addr0;
3254   u16 lo_port0, i0;
3255   snat_det_session_t * ses0 = 0;
3256   ip4_address_t in_addr;
3257   u16 in_port;
3258
3259   icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
3260   echo0 = (icmp_echo_header_t *)(icmp0+1);
3261   sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
3262   rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
3263
3264   if (!icmp_is_error_message (icmp0))
3265     {
3266       protocol = SNAT_PROTOCOL_ICMP;
3267       in_addr = ip0->src_address;
3268       in_port = echo0->identifier;
3269     }
3270   else
3271     {
3272       inner_ip0 = (ip4_header_t *)(echo0+1);
3273       l4_header = ip4_next_header (inner_ip0);
3274       protocol = ip_proto_to_snat_proto (inner_ip0->protocol);
3275       in_addr = inner_ip0->dst_address;
3276       switch (protocol)
3277         {
3278         case SNAT_PROTOCOL_ICMP:
3279           inner_icmp0 = (icmp46_header_t*)l4_header;
3280           inner_echo0 = (icmp_echo_header_t *)(inner_icmp0+1);
3281           in_port = inner_echo0->identifier;
3282           break;
3283         case SNAT_PROTOCOL_UDP:
3284         case SNAT_PROTOCOL_TCP:
3285           in_port = ((tcp_udp_header_t*)l4_header)->dst_port;
3286           break;
3287         default:
3288           b0->error = node->errors[SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL];
3289           next0 = SNAT_IN2OUT_NEXT_DROP;
3290           goto out;
3291         }
3292     }
3293
3294   dm0 = snat_det_map_by_user(sm, &in_addr);
3295   if (PREDICT_FALSE(!dm0))
3296     {
3297       clib_warning("no match for internal host %U",
3298                    format_ip4_address, &in_addr);
3299       if (PREDICT_FALSE(snat_not_translate_fast(sm, node, sw_if_index0, ip0,
3300           IP_PROTOCOL_ICMP, rx_fib_index0)))
3301         {
3302           dont_translate = 1;
3303           goto out;
3304         }
3305       next0 = SNAT_IN2OUT_NEXT_DROP;
3306       b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
3307       goto out;
3308     }
3309
3310   snat_det_forward(dm0, &in_addr, &new_addr0, &lo_port0);
3311
3312   key0.ext_host_addr = ip0->dst_address;
3313   key0.ext_host_port = 0;
3314
3315   ses0 = snat_det_find_ses_by_in(dm0, &in_addr, in_port, key0);
3316   if (PREDICT_FALSE(!ses0))
3317     {
3318       if (PREDICT_FALSE(snat_not_translate_fast(sm, node, sw_if_index0, ip0,
3319           IP_PROTOCOL_ICMP, rx_fib_index0)))
3320         {
3321           dont_translate = 1;
3322           goto out;
3323         }
3324       if (icmp0->type != ICMP4_echo_request)
3325         {
3326           b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
3327           next0 = SNAT_IN2OUT_NEXT_DROP;
3328           goto out;
3329         }
3330       for (i0 = 0; i0 < dm0->ports_per_host; i0++)
3331         {
3332           key0.out_port = clib_host_to_net_u16 (lo_port0 +
3333             ((i0 + clib_net_to_host_u16 (echo0->identifier)) % dm0->ports_per_host));
3334
3335           if (snat_det_get_ses_by_out (dm0, &in_addr, key0.as_u64))
3336             continue;
3337
3338           ses0 = snat_det_ses_create(dm0, &in_addr, echo0->identifier, &key0);
3339           break;
3340         }
3341       if (PREDICT_FALSE(!ses0))
3342         {
3343           next0 = SNAT_IN2OUT_NEXT_DROP;
3344           b0->error = node->errors[SNAT_IN2OUT_ERROR_OUT_OF_PORTS];
3345           goto out;
3346         }
3347     }
3348
3349   if (PREDICT_FALSE(icmp0->type != ICMP4_echo_request &&
3350                     !icmp_is_error_message (icmp0)))
3351     {
3352       b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
3353       next0 = SNAT_IN2OUT_NEXT_DROP;
3354       goto out;
3355     }
3356
3357   u32 now = (u32) vlib_time_now (sm->vlib_main);
3358
3359   ses0->state = SNAT_SESSION_ICMP_ACTIVE;
3360   ses0->expire = now + sm->icmp_timeout;
3361
3362 out:
3363   *p_proto = protocol;
3364   if (ses0)
3365     {
3366       p_value->addr = new_addr0;
3367       p_value->fib_index = sm->outside_fib_index;
3368       p_value->port = ses0->out.out_port;
3369     }
3370   *p_dont_translate = dont_translate;
3371   if (d)
3372     *(snat_det_session_t**)d = ses0;
3373   if (e)
3374     *(snat_det_map_t**)e = dm0;
3375   return next0;
3376 }
3377
3378 /**********************/
3379 /*** worker handoff ***/
3380 /**********************/
3381 static inline uword
3382 snat_in2out_worker_handoff_fn_inline (vlib_main_t * vm,
3383                                       vlib_node_runtime_t * node,
3384                                       vlib_frame_t * frame,
3385                                       u8 is_output)
3386 {
3387   snat_main_t *sm = &snat_main;
3388   vlib_thread_main_t *tm = vlib_get_thread_main ();
3389   u32 n_left_from, *from, *to_next = 0;
3390   static __thread vlib_frame_queue_elt_t **handoff_queue_elt_by_worker_index;
3391   static __thread vlib_frame_queue_t **congested_handoff_queue_by_worker_index
3392     = 0;
3393   vlib_frame_queue_elt_t *hf = 0;
3394   vlib_frame_t *f = 0;
3395   int i;
3396   u32 n_left_to_next_worker = 0, *to_next_worker = 0;
3397   u32 next_worker_index = 0;
3398   u32 current_worker_index = ~0;
3399   u32 thread_index = vlib_get_thread_index ();
3400   u32 fq_index;
3401   u32 to_node_index;
3402
3403   ASSERT (vec_len (sm->workers));
3404
3405   if (is_output)
3406     {
3407       fq_index = sm->fq_in2out_output_index;
3408       to_node_index = sm->in2out_output_node_index;
3409     }
3410   else
3411     {
3412       fq_index = sm->fq_in2out_index;
3413       to_node_index = sm->in2out_node_index;
3414     }
3415
3416   if (PREDICT_FALSE (handoff_queue_elt_by_worker_index == 0))
3417     {
3418       vec_validate (handoff_queue_elt_by_worker_index, tm->n_vlib_mains - 1);
3419
3420       vec_validate_init_empty (congested_handoff_queue_by_worker_index,
3421                                sm->first_worker_index + sm->num_workers - 1,
3422                                (vlib_frame_queue_t *) (~0));
3423     }
3424
3425   from = vlib_frame_vector_args (frame);
3426   n_left_from = frame->n_vectors;
3427
3428   while (n_left_from > 0)
3429     {
3430       u32 bi0;
3431       vlib_buffer_t *b0;
3432       u32 sw_if_index0;
3433       u32 rx_fib_index0;
3434       ip4_header_t * ip0;
3435       u8 do_handoff;
3436
3437       bi0 = from[0];
3438       from += 1;
3439       n_left_from -= 1;
3440
3441       b0 = vlib_get_buffer (vm, bi0);
3442
3443       sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3444       rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index(sw_if_index0);
3445
3446       ip0 = vlib_buffer_get_current (b0);
3447
3448       next_worker_index = sm->worker_in2out_cb(ip0, rx_fib_index0);
3449
3450       if (PREDICT_FALSE (next_worker_index != thread_index))
3451         {
3452           do_handoff = 1;
3453
3454           if (next_worker_index != current_worker_index)
3455             {
3456               if (hf)
3457                 hf->n_vectors = VLIB_FRAME_SIZE - n_left_to_next_worker;
3458
3459               hf = vlib_get_worker_handoff_queue_elt (fq_index,
3460                                                       next_worker_index,
3461                                                       handoff_queue_elt_by_worker_index);
3462
3463               n_left_to_next_worker = VLIB_FRAME_SIZE - hf->n_vectors;
3464               to_next_worker = &hf->buffer_index[hf->n_vectors];
3465               current_worker_index = next_worker_index;
3466             }
3467
3468           /* enqueue to correct worker thread */
3469           to_next_worker[0] = bi0;
3470           to_next_worker++;
3471           n_left_to_next_worker--;
3472
3473           if (n_left_to_next_worker == 0)
3474             {
3475               hf->n_vectors = VLIB_FRAME_SIZE;
3476               vlib_put_frame_queue_elt (hf);
3477               current_worker_index = ~0;
3478               handoff_queue_elt_by_worker_index[next_worker_index] = 0;
3479               hf = 0;
3480             }
3481         }
3482       else
3483         {
3484           do_handoff = 0;
3485           /* if this is 1st frame */
3486           if (!f)
3487             {
3488               f = vlib_get_frame_to_node (vm, to_node_index);
3489               to_next = vlib_frame_vector_args (f);
3490             }
3491
3492           to_next[0] = bi0;
3493           to_next += 1;
3494           f->n_vectors++;
3495         }
3496
3497       if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
3498                          && (b0->flags & VLIB_BUFFER_IS_TRACED)))
3499         {
3500           snat_in2out_worker_handoff_trace_t *t =
3501             vlib_add_trace (vm, node, b0, sizeof (*t));
3502           t->next_worker_index = next_worker_index;
3503           t->do_handoff = do_handoff;
3504         }
3505     }
3506
3507   if (f)
3508     vlib_put_frame_to_node (vm, to_node_index, f);
3509
3510   if (hf)
3511     hf->n_vectors = VLIB_FRAME_SIZE - n_left_to_next_worker;
3512
3513   /* Ship frames to the worker nodes */
3514   for (i = 0; i < vec_len (handoff_queue_elt_by_worker_index); i++)
3515     {
3516       if (handoff_queue_elt_by_worker_index[i])
3517         {
3518           hf = handoff_queue_elt_by_worker_index[i];
3519           /*
3520            * It works better to let the handoff node
3521            * rate-adapt, always ship the handoff queue element.
3522            */
3523           if (1 || hf->n_vectors == hf->last_n_vectors)
3524             {
3525               vlib_put_frame_queue_elt (hf);
3526               handoff_queue_elt_by_worker_index[i] = 0;
3527             }
3528           else
3529             hf->last_n_vectors = hf->n_vectors;
3530         }
3531       congested_handoff_queue_by_worker_index[i] =
3532         (vlib_frame_queue_t *) (~0);
3533     }
3534   hf = 0;
3535   current_worker_index = ~0;
3536   return frame->n_vectors;
3537 }
3538
3539 static uword
3540 snat_in2out_worker_handoff_fn (vlib_main_t * vm,
3541                                vlib_node_runtime_t * node,
3542                                vlib_frame_t * frame)
3543 {
3544   return snat_in2out_worker_handoff_fn_inline (vm, node, frame, 0);
3545 }
3546
3547 VLIB_REGISTER_NODE (snat_in2out_worker_handoff_node) = {
3548   .function = snat_in2out_worker_handoff_fn,
3549   .name = "nat44-in2out-worker-handoff",
3550   .vector_size = sizeof (u32),
3551   .format_trace = format_snat_in2out_worker_handoff_trace,
3552   .type = VLIB_NODE_TYPE_INTERNAL,
3553
3554   .n_next_nodes = 1,
3555
3556   .next_nodes = {
3557     [0] = "error-drop",
3558   },
3559 };
3560
3561 VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_worker_handoff_node,
3562                               snat_in2out_worker_handoff_fn);
3563
3564 static uword
3565 snat_in2out_output_worker_handoff_fn (vlib_main_t * vm,
3566                                       vlib_node_runtime_t * node,
3567                                       vlib_frame_t * frame)
3568 {
3569   return snat_in2out_worker_handoff_fn_inline (vm, node, frame, 1);
3570 }
3571
3572 VLIB_REGISTER_NODE (snat_in2out_output_worker_handoff_node) = {
3573   .function = snat_in2out_output_worker_handoff_fn,
3574   .name = "nat44-in2out-output-worker-handoff",
3575   .vector_size = sizeof (u32),
3576   .format_trace = format_snat_in2out_worker_handoff_trace,
3577   .type = VLIB_NODE_TYPE_INTERNAL,
3578
3579   .n_next_nodes = 1,
3580
3581   .next_nodes = {
3582     [0] = "error-drop",
3583   },
3584 };
3585
3586 VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_output_worker_handoff_node,
3587                               snat_in2out_output_worker_handoff_fn);
3588
3589 static_always_inline int
3590 is_hairpinning (snat_main_t *sm, ip4_address_t * dst_addr)
3591 {
3592   snat_address_t * ap;
3593   clib_bihash_kv_8_8_t kv, value;
3594   snat_session_key_t m_key;
3595
3596   vec_foreach (ap, sm->addresses)
3597     {
3598       if (ap->addr.as_u32 == dst_addr->as_u32)
3599         return 1;
3600     }
3601
3602   m_key.addr.as_u32 = dst_addr->as_u32;
3603   m_key.fib_index = sm->outside_fib_index;
3604   m_key.port = 0;
3605   m_key.protocol = 0;
3606   kv.key = m_key.as_u64;
3607   if (!clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
3608     return 1;
3609
3610   return 0;
3611 }
3612
3613 static uword
3614 snat_hairpin_dst_fn (vlib_main_t * vm,
3615                      vlib_node_runtime_t * node,
3616                      vlib_frame_t * frame)
3617 {
3618   u32 n_left_from, * from, * to_next;
3619   snat_in2out_next_t next_index;
3620   u32 pkts_processed = 0;
3621   snat_main_t * sm = &snat_main;
3622
3623   from = vlib_frame_vector_args (frame);
3624   n_left_from = frame->n_vectors;
3625   next_index = node->cached_next_index;
3626
3627   while (n_left_from > 0)
3628     {
3629       u32 n_left_to_next;
3630
3631       vlib_get_next_frame (vm, node, next_index,
3632                            to_next, n_left_to_next);
3633
3634       while (n_left_from > 0 && n_left_to_next > 0)
3635         {
3636           u32 bi0;
3637           vlib_buffer_t * b0;
3638           u32 next0;
3639           ip4_header_t * ip0;
3640           u32 proto0;
3641
3642           /* speculatively enqueue b0 to the current next frame */
3643           bi0 = from[0];
3644           to_next[0] = bi0;
3645           from += 1;
3646           to_next += 1;
3647           n_left_from -= 1;
3648           n_left_to_next -= 1;
3649
3650           b0 = vlib_get_buffer (vm, bi0);
3651           next0 = SNAT_IN2OUT_NEXT_LOOKUP;
3652           ip0 = vlib_buffer_get_current (b0);
3653
3654           proto0 = ip_proto_to_snat_proto (ip0->protocol);
3655
3656           vnet_buffer (b0)->snat.flags = 0;
3657           if (PREDICT_FALSE (is_hairpinning (sm, &ip0->dst_address)))
3658             {
3659               if (proto0 == SNAT_PROTOCOL_TCP || proto0 == SNAT_PROTOCOL_UDP)
3660                 {
3661                   udp_header_t * udp0 = ip4_next_header (ip0);
3662                   tcp_header_t * tcp0 = (tcp_header_t *) udp0;
3663
3664                   snat_hairpinning (sm, b0, ip0, udp0, tcp0, proto0);
3665                 }
3666               else if (proto0 == SNAT_PROTOCOL_ICMP)
3667                 {
3668                   icmp46_header_t * icmp0 = ip4_next_header (ip0);
3669
3670                   snat_icmp_hairpinning (sm, b0, ip0, icmp0);
3671                 }
3672               else
3673                 {
3674                   snat_hairpinning_unknown_proto (sm, b0, ip0);
3675                 }
3676
3677               vnet_buffer (b0)->snat.flags = SNAT_FLAG_HAIRPINNING;
3678             }
3679
3680           pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
3681
3682           /* verify speculative enqueue, maybe switch current next frame */
3683           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
3684                                            to_next, n_left_to_next,
3685                                            bi0, next0);
3686          }
3687
3688       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
3689     }
3690
3691   vlib_node_increment_counter (vm, snat_hairpin_dst_node.index,
3692                                SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
3693                                pkts_processed);
3694   return frame->n_vectors;
3695 }
3696
3697 VLIB_REGISTER_NODE (snat_hairpin_dst_node) = {
3698   .function = snat_hairpin_dst_fn,
3699   .name = "nat44-hairpin-dst",
3700   .vector_size = sizeof (u32),
3701   .type = VLIB_NODE_TYPE_INTERNAL,
3702   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
3703   .error_strings = snat_in2out_error_strings,
3704   .n_next_nodes = 2,
3705   .next_nodes = {
3706     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
3707     [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
3708   },
3709 };
3710
3711 VLIB_NODE_FUNCTION_MULTIARCH (snat_hairpin_dst_node,
3712                               snat_hairpin_dst_fn);
3713
3714 static uword
3715 snat_hairpin_src_fn (vlib_main_t * vm,
3716                      vlib_node_runtime_t * node,
3717                      vlib_frame_t * frame)
3718 {
3719   u32 n_left_from, * from, * to_next;
3720   snat_in2out_next_t next_index;
3721   u32 pkts_processed = 0;
3722   snat_main_t *sm = &snat_main;
3723
3724   from = vlib_frame_vector_args (frame);
3725   n_left_from = frame->n_vectors;
3726   next_index = node->cached_next_index;
3727
3728   while (n_left_from > 0)
3729     {
3730       u32 n_left_to_next;
3731
3732       vlib_get_next_frame (vm, node, next_index,
3733                            to_next, n_left_to_next);
3734
3735       while (n_left_from > 0 && n_left_to_next > 0)
3736         {
3737           u32 bi0;
3738           vlib_buffer_t * b0;
3739           u32 next0;
3740           snat_interface_t *i;
3741           u32 sw_if_index0;
3742
3743           /* speculatively enqueue b0 to the current next frame */
3744           bi0 = from[0];
3745           to_next[0] = bi0;
3746           from += 1;
3747           to_next += 1;
3748           n_left_from -= 1;
3749           n_left_to_next -= 1;
3750
3751           b0 = vlib_get_buffer (vm, bi0);
3752           sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
3753           next0 = SNAT_HAIRPIN_SRC_NEXT_INTERFACE_OUTPUT;
3754
3755           pool_foreach (i, sm->output_feature_interfaces,
3756           ({
3757             /* Only packets from NAT inside interface */
3758             if ((nat_interface_is_inside(i)) && (sw_if_index0 == i->sw_if_index))
3759               {
3760                 if (PREDICT_FALSE ((vnet_buffer (b0)->snat.flags) &
3761                                     SNAT_FLAG_HAIRPINNING))
3762                   {
3763                     if (PREDICT_TRUE (sm->num_workers > 1))
3764                       next0 = SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT_WH;
3765                     else
3766                       next0 = SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT;
3767                   }
3768                 break;
3769               }
3770           }));
3771
3772           pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
3773
3774           /* verify speculative enqueue, maybe switch current next frame */
3775           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
3776                                            to_next, n_left_to_next,
3777                                            bi0, next0);
3778          }
3779
3780       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
3781     }
3782
3783   vlib_node_increment_counter (vm, snat_hairpin_src_node.index,
3784                                SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
3785                                pkts_processed);
3786   return frame->n_vectors;
3787 }
3788
3789 VLIB_REGISTER_NODE (snat_hairpin_src_node) = {
3790   .function = snat_hairpin_src_fn,
3791   .name = "nat44-hairpin-src",
3792   .vector_size = sizeof (u32),
3793   .type = VLIB_NODE_TYPE_INTERNAL,
3794   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
3795   .error_strings = snat_in2out_error_strings,
3796   .n_next_nodes = SNAT_HAIRPIN_SRC_N_NEXT,
3797   .next_nodes = {
3798      [SNAT_HAIRPIN_SRC_NEXT_DROP] = "error-drop",
3799      [SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT] = "nat44-in2out-output",
3800      [SNAT_HAIRPIN_SRC_NEXT_INTERFACE_OUTPUT] = "interface-output",
3801      [SNAT_HAIRPIN_SRC_NEXT_SNAT_IN2OUT_WH] = "nat44-in2out-output-worker-handoff",
3802   },
3803 };
3804
3805 VLIB_NODE_FUNCTION_MULTIARCH (snat_hairpin_src_node,
3806                               snat_hairpin_src_fn);
3807
3808 static uword
3809 snat_in2out_fast_static_map_fn (vlib_main_t * vm,
3810                                 vlib_node_runtime_t * node,
3811                                 vlib_frame_t * frame)
3812 {
3813   u32 n_left_from, * from, * to_next;
3814   snat_in2out_next_t next_index;
3815   u32 pkts_processed = 0;
3816   snat_main_t * sm = &snat_main;
3817   u32 stats_node_index;
3818
3819   stats_node_index = snat_in2out_fast_node.index;
3820
3821   from = vlib_frame_vector_args (frame);
3822   n_left_from = frame->n_vectors;
3823   next_index = node->cached_next_index;
3824
3825   while (n_left_from > 0)
3826     {
3827       u32 n_left_to_next;
3828
3829       vlib_get_next_frame (vm, node, next_index,
3830                            to_next, n_left_to_next);
3831
3832       while (n_left_from > 0 && n_left_to_next > 0)
3833         {
3834           u32 bi0;
3835           vlib_buffer_t * b0;
3836           u32 next0;
3837           u32 sw_if_index0;
3838           ip4_header_t * ip0;
3839           ip_csum_t sum0;
3840           u32 new_addr0, old_addr0;
3841           u16 old_port0, new_port0;
3842           udp_header_t * udp0;
3843           tcp_header_t * tcp0;
3844           icmp46_header_t * icmp0;
3845           snat_session_key_t key0, sm0;
3846           u32 proto0;
3847           u32 rx_fib_index0;
3848
3849           /* speculatively enqueue b0 to the current next frame */
3850           bi0 = from[0];
3851           to_next[0] = bi0;
3852           from += 1;
3853           to_next += 1;
3854           n_left_from -= 1;
3855           n_left_to_next -= 1;
3856
3857           b0 = vlib_get_buffer (vm, bi0);
3858           next0 = SNAT_IN2OUT_NEXT_LOOKUP;
3859
3860           ip0 = vlib_buffer_get_current (b0);
3861           udp0 = ip4_next_header (ip0);
3862           tcp0 = (tcp_header_t *) udp0;
3863           icmp0 = (icmp46_header_t *) udp0;
3864
3865           sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
3866           rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index(sw_if_index0);
3867
3868           if (PREDICT_FALSE(ip0->ttl == 1))
3869             {
3870               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
3871               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
3872                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
3873                                            0);
3874               next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
3875               goto trace0;
3876             }
3877
3878           proto0 = ip_proto_to_snat_proto (ip0->protocol);
3879
3880           if (PREDICT_FALSE (proto0 == ~0))
3881               goto trace0;
3882
3883           if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
3884             {
3885               next0 = icmp_in2out(sm, b0, ip0, icmp0, sw_if_index0,
3886                                   rx_fib_index0, node, next0, ~0, 0, 0);
3887               goto trace0;
3888             }
3889
3890           key0.addr = ip0->src_address;
3891           key0.protocol = proto0;
3892           key0.port = udp0->src_port;
3893           key0.fib_index = rx_fib_index0;
3894
3895           if (snat_static_mapping_match(sm, key0, &sm0, 0, 0, 0))
3896             {
3897               b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
3898               next0= SNAT_IN2OUT_NEXT_DROP;
3899               goto trace0;
3900             }
3901
3902           new_addr0 = sm0.addr.as_u32;
3903           new_port0 = sm0.port;
3904           vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
3905           old_addr0 = ip0->src_address.as_u32;
3906           ip0->src_address.as_u32 = new_addr0;
3907
3908           sum0 = ip0->checksum;
3909           sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
3910                                  ip4_header_t,
3911                                  src_address /* changed member */);
3912           ip0->checksum = ip_csum_fold (sum0);
3913
3914           if (PREDICT_FALSE(new_port0 != udp0->dst_port))
3915             {
3916               if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
3917                 {
3918                   old_port0 = tcp0->src_port;
3919                   tcp0->src_port = new_port0;
3920
3921                   sum0 = tcp0->checksum;
3922                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
3923                                          ip4_header_t,
3924                                          dst_address /* changed member */);
3925                   sum0 = ip_csum_update (sum0, old_port0, new_port0,
3926                                          ip4_header_t /* cheat */,
3927                                          length /* changed member */);
3928                   tcp0->checksum = ip_csum_fold(sum0);
3929                 }
3930               else
3931                 {
3932                   old_port0 = udp0->src_port;
3933                   udp0->src_port = new_port0;
3934                   udp0->checksum = 0;
3935                 }
3936             }
3937           else
3938             {
3939               if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
3940                 {
3941                   sum0 = tcp0->checksum;
3942                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
3943                                          ip4_header_t,
3944                                          dst_address /* changed member */);
3945                   tcp0->checksum = ip_csum_fold(sum0);
3946                 }
3947             }
3948
3949           /* Hairpinning */
3950           snat_hairpinning (sm, b0, ip0, udp0, tcp0, proto0);
3951
3952         trace0:
3953           if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
3954                             && (b0->flags & VLIB_BUFFER_IS_TRACED)))
3955             {
3956               snat_in2out_trace_t *t =
3957                  vlib_add_trace (vm, node, b0, sizeof (*t));
3958               t->sw_if_index = sw_if_index0;
3959               t->next_index = next0;
3960             }
3961
3962           pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
3963
3964           /* verify speculative enqueue, maybe switch current next frame */
3965           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
3966                                            to_next, n_left_to_next,
3967                                            bi0, next0);
3968         }
3969
3970       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
3971     }
3972
3973   vlib_node_increment_counter (vm, stats_node_index,
3974                                SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
3975                                pkts_processed);
3976   return frame->n_vectors;
3977 }
3978
3979
3980 VLIB_REGISTER_NODE (snat_in2out_fast_node) = {
3981   .function = snat_in2out_fast_static_map_fn,
3982   .name = "nat44-in2out-fast",
3983   .vector_size = sizeof (u32),
3984   .format_trace = format_snat_in2out_fast_trace,
3985   .type = VLIB_NODE_TYPE_INTERNAL,
3986
3987   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
3988   .error_strings = snat_in2out_error_strings,
3989
3990   .runtime_data_bytes = sizeof (snat_runtime_t),
3991
3992   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
3993
3994   /* edit / add dispositions here */
3995   .next_nodes = {
3996     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
3997     [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
3998     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
3999     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
4000     [SNAT_IN2OUT_NEXT_REASS] = "nat44-in2out-reass",
4001   },
4002 };
4003
4004 VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_fast_node, snat_in2out_fast_static_map_fn);