src/plugins/snat/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 <snat/snat.h>
  25 #include <snat/snat_ipfix_logging.h>
  26 #include <snat/snat_det.h>
  27
  28 #include <vppinfra/hash.h>
  29 #include <vppinfra/error.h>
  30 #include <vppinfra/elog.h>
  31
  32 typedef struct {
  33   u32 sw_if_index;
  34   u32 next_index;
  35   u32 session_index;
  36   u32 is_slow_path;
  37 } snat_in2out_trace_t;
  38
  39 typedef struct {
  40   u32 next_worker_index;
  41   u8 do_handoff;
  42 } snat_in2out_worker_handoff_trace_t;
  43
  44 /* packet trace format function */
  45 static u8 * format_snat_in2out_trace (u8 * s, va_list * args)
  46 {
  47   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  48   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  49   snat_in2out_trace_t * t = va_arg (*args, snat_in2out_trace_t *);
  50   char * tag;
  51
  52   tag = t->is_slow_path ? "SNAT_IN2OUT_SLOW_PATH" : "SNAT_IN2OUT_FAST_PATH";
  53
  54   s = format (s, "%s: sw_if_index %d, next index %d, session %d", tag,
  55               t->sw_if_index, t->next_index, t->session_index);
  56
  57   return s;
  58 }
  59
  60 static u8 * format_snat_in2out_fast_trace (u8 * s, va_list * args)
  61 {
  62   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  63   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  64   snat_in2out_trace_t * t = va_arg (*args, snat_in2out_trace_t *);
  65
  66   s = format (s, "SANT_IN2OUT_FAST: sw_if_index %d, next index %d",
  67               t->sw_if_index, t->next_index);
  68
  69   return s;
  70 }
  71
  72 static u8 * format_snat_in2out_worker_handoff_trace (u8 * s, va_list * args)
  73 {
  74   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  75   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  76   snat_in2out_worker_handoff_trace_t * t =
  77     va_arg (*args, snat_in2out_worker_handoff_trace_t *);
  78   char * m;
  79
  80   m = t->do_handoff ? "next worker" : "same worker";
  81   s = format (s, "SNAT_IN2OUT_WORKER_HANDOFF: %s %d", m, t->next_worker_index);
  82
  83   return s;
  84 }
  85
  86 vlib_node_registration_t snat_in2out_node;
  87 vlib_node_registration_t snat_in2out_slowpath_node;
  88 vlib_node_registration_t snat_in2out_fast_node;
  89 vlib_node_registration_t snat_in2out_worker_handoff_node;
  90 vlib_node_registration_t snat_det_in2out_node;
  91
  92 #define foreach_snat_in2out_error                       \
  93 _(UNSUPPORTED_PROTOCOL, "Unsupported protocol")         \
  94 _(IN2OUT_PACKETS, "Good in2out packets processed")      \
  95 _(OUT_OF_PORTS, "Out of ports")                         \
  96 _(BAD_OUTSIDE_FIB, "Outside VRF ID not found")          \
  97 _(BAD_ICMP_TYPE, "unsupported ICMP type")               \
  98 _(NO_TRANSLATION, "No translation")
  99
 100 typedef enum {
 101 #define _(sym,str) SNAT_IN2OUT_ERROR_##sym,
 102   foreach_snat_in2out_error
 103 #undef _
 104   SNAT_IN2OUT_N_ERROR,
 105 } snat_in2out_error_t;
 106
 107 static char * snat_in2out_error_strings[] = {
 108 #define _(sym,string) string,
 109   foreach_snat_in2out_error
 110 #undef _
 111 };
 112
 113 typedef enum {
 114   SNAT_IN2OUT_NEXT_LOOKUP,
 115   SNAT_IN2OUT_NEXT_DROP,
 116   SNAT_IN2OUT_NEXT_ICMP_ERROR,
 117   SNAT_IN2OUT_NEXT_SLOW_PATH,
 118   SNAT_IN2OUT_N_NEXT,
 119 } snat_in2out_next_t;
 120
 121 /**
 122  * @brief Check if packet should be translated
 123  *
 124  * Packets aimed at outside interface and external addresss with active session
 125  * should be translated.
 126  *
 127  * @param sm            SNAT main
 128  * @param rt            SNAT runtime data
 129  * @param sw_if_index0  index of the inside interface
 130  * @param ip0           IPv4 header
 131  * @param proto0        SNAT protocol
 132  * @param rx_fib_index0 RX FIB index
 133  *
 134  * @returns 0 if packet should be translated otherwise 1
 135  */
 136 static inline int
 137 snat_not_translate_fast (snat_main_t * sm, vlib_node_runtime_t *node,
 138                          u32 sw_if_index0, ip4_header_t * ip0, u32 proto0,
 139                          u32 rx_fib_index0)
 140 {
 141   fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
 142   fib_prefix_t pfx = {
 143     .fp_proto = FIB_PROTOCOL_IP4,
 144     .fp_len = 32,
 145     .fp_addr = {
 146         .ip4.as_u32 = ip0->dst_address.as_u32,
 147     },
 148   };
 149
 150   /* Don't NAT packet aimed at the intfc address */
 151   if (PREDICT_FALSE(is_interface_addr(sm, node, sw_if_index0,
 152                                       ip0->dst_address.as_u32)))
 153     return 1;
 154
 155   fei = fib_table_lookup (rx_fib_index0, &pfx);
 156   if (FIB_NODE_INDEX_INVALID != fei)
 157     {
 158       u32 sw_if_index = fib_entry_get_resolving_interface (fei);
 159       if (sw_if_index == ~0)
 160         {
 161           fei = fib_table_lookup (sm->outside_fib_index, &pfx);
 162           if (FIB_NODE_INDEX_INVALID != fei)
 163             sw_if_index = fib_entry_get_resolving_interface (fei);
 164         }
 165       snat_interface_t *i;
 166       pool_foreach (i, sm->interfaces,
 167       ({
 168         /* NAT packet aimed at outside interface */
 169         if ((i->is_inside == 0) && (sw_if_index == i->sw_if_index))
 170           return 0;
 171       }));
 172     }
 173
 174   return 1;
 175 }
 176
 177 static inline int
 178 snat_not_translate (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   udp_header_t * udp0 = ip4_next_header (ip0);
 183   snat_session_key_t key0, sm0;
 184   clib_bihash_kv_8_8_t kv0, value0;
 185
 186   key0.addr = ip0->dst_address;
 187   key0.port = udp0->dst_port;
 188   key0.protocol = proto0;
 189   key0.fib_index = sm->outside_fib_index;
 190   kv0.key = key0.as_u64;
 191
 192   /* NAT packet aimed at external address if */
 193   /* has active sessions */
 194   if (clib_bihash_search_8_8 (&sm->out2in, &kv0, &value0))
 195     {
 196       /* or is static mappings */
 197       if (!snat_static_mapping_match(sm, key0, &sm0, 1, 0))
 198         return 0;
 199     }
 200   else
 201     return 0;
 202
 203   return snat_not_translate_fast(sm, node, sw_if_index0, ip0, proto0,
 204                                  rx_fib_index0);
 205 }
 206
 207 static u32 slow_path (snat_main_t *sm, vlib_buffer_t *b0,
 208                       ip4_header_t * ip0,
 209                       u32 rx_fib_index0,
 210                       snat_session_key_t * key0,
 211                       snat_session_t ** sessionp,
 212                       vlib_node_runtime_t * node,
 213                       u32 next0,
 214                       u32 thread_index)
 215 {
 216   snat_user_t *u;
 217   snat_user_key_t user_key;
 218   snat_session_t *s;
 219   clib_bihash_kv_8_8_t kv0, value0;
 220   u32 oldest_per_user_translation_list_index;
 221   dlist_elt_t * oldest_per_user_translation_list_elt;
 222   dlist_elt_t * per_user_translation_list_elt;
 223   dlist_elt_t * per_user_list_head_elt;
 224   u32 session_index;
 225   snat_session_key_t key1;
 226   u32 address_index = ~0;
 227   u32 outside_fib_index;
 228   uword * p;
 229   snat_worker_key_t worker_by_out_key;
 230
 231   p = hash_get (sm->ip4_main->fib_index_by_table_id, sm->outside_vrf_id);
 232   if (! p)
 233     {
 234       b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_OUTSIDE_FIB];
 235       return SNAT_IN2OUT_NEXT_DROP;
 236     }
 237   outside_fib_index = p[0];
 238
 239   key1.protocol = key0->protocol;
 240   user_key.addr = ip0->src_address;
 241   user_key.fib_index = rx_fib_index0;
 242   kv0.key = user_key.as_u64;
 243
 244   /* Ever heard of the "user" = src ip4 address before? */
 245   if (clib_bihash_search_8_8 (&sm->user_hash, &kv0, &value0))
 246     {
 247       /* no, make a new one */
 248       pool_get (sm->per_thread_data[thread_index].users, u);
 249       memset (u, 0, sizeof (*u));
 250       u->addr = ip0->src_address;
 251       u->fib_index = rx_fib_index0;
 252
 253       pool_get (sm->per_thread_data[thread_index].list_pool, per_user_list_head_elt);
 254
 255       u->sessions_per_user_list_head_index = per_user_list_head_elt -
 256         sm->per_thread_data[thread_index].list_pool;
 257
 258       clib_dlist_init (sm->per_thread_data[thread_index].list_pool,
 259                        u->sessions_per_user_list_head_index);
 260
 261       kv0.value = u - sm->per_thread_data[thread_index].users;
 262
 263       /* add user */
 264       clib_bihash_add_del_8_8 (&sm->user_hash, &kv0, 1 /* is_add */);
 265     }
 266   else
 267     {
 268       u = pool_elt_at_index (sm->per_thread_data[thread_index].users,
 269                              value0.value);
 270     }
 271
 272   /* Over quota? Recycle the least recently used dynamic translation */
 273   if (u->nsessions >= sm->max_translations_per_user)
 274     {
 275       /* Remove the oldest dynamic translation */
 276       do {
 277           oldest_per_user_translation_list_index =
 278             clib_dlist_remove_head (sm->per_thread_data[thread_index].list_pool,
 279                                     u->sessions_per_user_list_head_index);
 280
 281           ASSERT (oldest_per_user_translation_list_index != ~0);
 282
 283           /* add it back to the end of the LRU list */
 284           clib_dlist_addtail (sm->per_thread_data[thread_index].list_pool,
 285                               u->sessions_per_user_list_head_index,
 286                               oldest_per_user_translation_list_index);
 287           /* Get the list element */
 288           oldest_per_user_translation_list_elt =
 289             pool_elt_at_index (sm->per_thread_data[thread_index].list_pool,
 290                                oldest_per_user_translation_list_index);
 291
 292           /* Get the session index from the list element */
 293           session_index = oldest_per_user_translation_list_elt->value;
 294
 295           /* Get the session */
 296           s = pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
 297                                  session_index);
 298       } while (snat_is_session_static (s));
 299
 300       /* Remove in2out, out2in keys */
 301       kv0.key = s->in2out.as_u64;
 302       if (clib_bihash_add_del_8_8 (&sm->in2out, &kv0, 0 /* is_add */))
 303           clib_warning ("in2out key delete failed");
 304       kv0.key = s->out2in.as_u64;
 305       if (clib_bihash_add_del_8_8 (&sm->out2in, &kv0, 0 /* is_add */))
 306           clib_warning ("out2in key delete failed");
 307
 308       /* log NAT event */
 309       snat_ipfix_logging_nat44_ses_delete(s->in2out.addr.as_u32,
 310                                           s->out2in.addr.as_u32,
 311                                           s->in2out.protocol,
 312                                           s->in2out.port,
 313                                           s->out2in.port,
 314                                           s->in2out.fib_index);
 315
 316       snat_free_outside_address_and_port
 317         (sm, &s->out2in, s->outside_address_index);
 318       s->outside_address_index = ~0;
 319
 320       if (snat_alloc_outside_address_and_port (sm, rx_fib_index0, &key1,
 321                                                &address_index))
 322         {
 323           ASSERT(0);
 324
 325           b0->error = node->errors[SNAT_IN2OUT_ERROR_OUT_OF_PORTS];
 326           return SNAT_IN2OUT_NEXT_DROP;
 327         }
 328       s->outside_address_index = address_index;
 329     }
 330   else
 331     {
 332       u8 static_mapping = 1;
 333
 334       /* First try to match static mapping by local address and port */
 335       if (snat_static_mapping_match (sm, *key0, &key1, 0, 0))
 336         {
 337           static_mapping = 0;
 338           /* Try to create dynamic translation */
 339           if (snat_alloc_outside_address_and_port (sm, rx_fib_index0, &key1,
 340                                                    &address_index))
 341             {
 342               b0->error = node->errors[SNAT_IN2OUT_ERROR_OUT_OF_PORTS];
 343               return SNAT_IN2OUT_NEXT_DROP;
 344             }
 345         }
 346
 347       /* Create a new session */
 348       pool_get (sm->per_thread_data[thread_index].sessions, s);
 349       memset (s, 0, sizeof (*s));
 350
 351       s->outside_address_index = address_index;
 352
 353       if (static_mapping)
 354         {
 355           u->nstaticsessions++;
 356           s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 357         }
 358       else
 359         {
 360           u->nsessions++;
 361         }
 362
 363       /* Create list elts */
 364       pool_get (sm->per_thread_data[thread_index].list_pool,
 365                 per_user_translation_list_elt);
 366       clib_dlist_init (sm->per_thread_data[thread_index].list_pool,
 367                        per_user_translation_list_elt -
 368                        sm->per_thread_data[thread_index].list_pool);
 369
 370       per_user_translation_list_elt->value =
 371         s - sm->per_thread_data[thread_index].sessions;
 372       s->per_user_index = per_user_translation_list_elt -
 373                           sm->per_thread_data[thread_index].list_pool;
 374       s->per_user_list_head_index = u->sessions_per_user_list_head_index;
 375
 376       clib_dlist_addtail (sm->per_thread_data[thread_index].list_pool,
 377                           s->per_user_list_head_index,
 378                           per_user_translation_list_elt -
 379                           sm->per_thread_data[thread_index].list_pool);
 380    }
 381
 382   s->in2out = *key0;
 383   s->out2in = key1;
 384   s->out2in.protocol = key0->protocol;
 385   s->out2in.fib_index = outside_fib_index;
 386   *sessionp = s;
 387
 388   /* Add to translation hashes */
 389   kv0.key = s->in2out.as_u64;
 390   kv0.value = s - sm->per_thread_data[thread_index].sessions;
 391   if (clib_bihash_add_del_8_8 (&sm->in2out, &kv0, 1 /* is_add */))
 392       clib_warning ("in2out key add failed");
 393
 394   kv0.key = s->out2in.as_u64;
 395   kv0.value = s - sm->per_thread_data[thread_index].sessions;
 396
 397   if (clib_bihash_add_del_8_8 (&sm->out2in, &kv0, 1 /* is_add */))
 398       clib_warning ("out2in key add failed");
 399
 400   /* Add to translated packets worker lookup */
 401   worker_by_out_key.addr = s->out2in.addr;
 402   worker_by_out_key.port = s->out2in.port;
 403   worker_by_out_key.fib_index = s->out2in.fib_index;
 404   kv0.key = worker_by_out_key.as_u64;
 405   kv0.value = thread_index;
 406   clib_bihash_add_del_8_8 (&sm->worker_by_out, &kv0, 1);
 407
 408   /* log NAT event */
 409   snat_ipfix_logging_nat44_ses_create(s->in2out.addr.as_u32,
 410                                       s->out2in.addr.as_u32,
 411                                       s->in2out.protocol,
 412                                       s->in2out.port,
 413                                       s->out2in.port,
 414                                       s->in2out.fib_index);
 415   return next0;
 416 }
 417
 418 static_always_inline
 419 snat_in2out_error_t icmp_get_key(ip4_header_t *ip0,
 420                                  snat_session_key_t *p_key0)
 421 {
 422   icmp46_header_t *icmp0;
 423   snat_session_key_t key0;
 424   icmp_echo_header_t *echo0, *inner_echo0 = 0;
 425   ip4_header_t *inner_ip0 = 0;
 426   void *l4_header = 0;
 427   icmp46_header_t *inner_icmp0;
 428
 429   icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
 430   echo0 = (icmp_echo_header_t *)(icmp0+1);
 431
 432   if (!icmp_is_error_message (icmp0))
 433     {
 434       key0.protocol = SNAT_PROTOCOL_ICMP;
 435       key0.addr = ip0->src_address;
 436       key0.port = echo0->identifier;
 437     }
 438   else
 439     {
 440       inner_ip0 = (ip4_header_t *)(echo0+1);
 441       l4_header = ip4_next_header (inner_ip0);
 442       key0.protocol = ip_proto_to_snat_proto (inner_ip0->protocol);
 443       key0.addr = inner_ip0->dst_address;
 444       switch (key0.protocol)
 445         {
 446         case SNAT_PROTOCOL_ICMP:
 447           inner_icmp0 = (icmp46_header_t*)l4_header;
 448           inner_echo0 = (icmp_echo_header_t *)(inner_icmp0+1);
 449           key0.port = inner_echo0->identifier;
 450           break;
 451         case SNAT_PROTOCOL_UDP:
 452         case SNAT_PROTOCOL_TCP:
 453           key0.port = ((tcp_udp_header_t*)l4_header)->dst_port;
 454           break;
 455         default:
 456           return SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL;
 457         }
 458     }
 459   *p_key0 = key0;
 460   return -1; /* success */
 461 }
 462
 463 /**
 464  * Get address and port values to be used for packet SNAT translation
 465  * and create session if needed
 466  *
 467  * @param[in,out] sm             SNAT main
 468  * @param[in,out] node           SNAT node runtime
 469  * @param[in] thread_index       thread index
 470  * @param[in,out] b0             buffer containing packet to be translated
 471  * @param[out] p_proto           protocol used for matching
 472  * @param[out] p_value           address and port after NAT translation
 473  * @param[out] p_dont_translate  if packet should not be translated
 474  * @param d                      optional parameter
 475  * @param e                      optional parameter
 476  */
 477 u32 icmp_match_in2out_slow(snat_main_t *sm, vlib_node_runtime_t *node,
 478                            u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
 479                            snat_session_key_t *p_value,
 480                            u8 *p_dont_translate, void *d, void *e)
 481 {
 482   ip4_header_t *ip0;
 483   icmp46_header_t *icmp0;
 484   u32 sw_if_index0;
 485   u32 rx_fib_index0;
 486   snat_session_key_t key0;
 487   snat_session_t *s0 = 0;
 488   u8 dont_translate = 0;
 489   clib_bihash_kv_8_8_t kv0, value0;
 490   u32 next0 = ~0;
 491   int err;
 492
 493   ip0 = vlib_buffer_get_current (b0);
 494   icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
 495   sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
 496   rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
 497
 498   err = icmp_get_key (ip0, &key0);
 499   if (err != -1)
 500     {
 501       b0->error = node->errors[err];
 502       next0 = SNAT_IN2OUT_NEXT_DROP;
 503       goto out;
 504     }
 505   key0.fib_index = rx_fib_index0;
 506
 507   kv0.key = key0.as_u64;
 508
 509   if (clib_bihash_search_8_8 (&sm->in2out, &kv0, &value0))
 510     {
 511       if (PREDICT_FALSE(snat_not_translate(sm, node, sw_if_index0, ip0,
 512           IP_PROTOCOL_ICMP, rx_fib_index0)))
 513         {
 514           dont_translate = 1;
 515           goto out;
 516         }
 517
 518       if (PREDICT_FALSE(icmp_is_error_message (icmp0)))
 519         {
 520           b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
 521           next0 = SNAT_IN2OUT_NEXT_DROP;
 522           goto out;
 523         }
 524
 525       next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0,
 526                          &s0, node, next0, thread_index);
 527
 528       if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
 529         goto out;
 530     }
 531   else
 532     {
 533       if (PREDICT_FALSE(icmp0->type != ICMP4_echo_request &&
 534                         icmp0->type != ICMP4_echo_reply &&
 535                         !icmp_is_error_message (icmp0)))
 536         {
 537           b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
 538           next0 = SNAT_IN2OUT_NEXT_DROP;
 539           goto out;
 540         }
 541
 542       s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
 543                               value0.value);
 544     }
 545
 546 out:
 547   *p_proto = key0.protocol;
 548   if (s0)
 549     *p_value = s0->out2in;
 550   *p_dont_translate = dont_translate;
 551   if (d)
 552     *(snat_session_t**)d = s0;
 553   return next0;
 554 }
 555
 556 /**
 557  * Get address and port values to be used for packet SNAT translation
 558  *
 559  * @param[in] sm                 SNAT main
 560  * @param[in,out] node           SNAT node runtime
 561  * @param[in] thread_index       thread index
 562  * @param[in,out] b0             buffer containing packet to be translated
 563  * @param[out] p_proto           protocol used for matching
 564  * @param[out] p_value           address and port after NAT translation
 565  * @param[out] p_dont_translate  if packet should not be translated
 566  * @param d                      optional parameter
 567  * @param e                      optional parameter
 568  */
 569 u32 icmp_match_in2out_fast(snat_main_t *sm, vlib_node_runtime_t *node,
 570                            u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
 571                            snat_session_key_t *p_value,
 572                            u8 *p_dont_translate, void *d, void *e)
 573 {
 574   ip4_header_t *ip0;
 575   icmp46_header_t *icmp0;
 576   u32 sw_if_index0;
 577   u32 rx_fib_index0;
 578   snat_session_key_t key0;
 579   snat_session_key_t sm0;
 580   u8 dont_translate = 0;
 581   u8 is_addr_only;
 582   u32 next0 = ~0;
 583   int err;
 584
 585   ip0 = vlib_buffer_get_current (b0);
 586   icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
 587   sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
 588   rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
 589
 590   err = icmp_get_key (ip0, &key0);
 591   if (err != -1)
 592     {
 593       b0->error = node->errors[err];
 594       next0 = SNAT_IN2OUT_NEXT_DROP;
 595       goto out2;
 596     }
 597   key0.fib_index = rx_fib_index0;
 598
 599   if (snat_static_mapping_match(sm, key0, &sm0, 0, &is_addr_only))
 600     {
 601       if (PREDICT_FALSE(snat_not_translate_fast(sm, node, sw_if_index0, ip0,
 602           IP_PROTOCOL_ICMP, rx_fib_index0)))
 603         {
 604           dont_translate = 1;
 605           goto out;
 606         }
 607
 608       if (icmp_is_error_message (icmp0))
 609         {
 610           next0 = SNAT_IN2OUT_NEXT_DROP;
 611           goto out;
 612         }
 613
 614       b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
 615       next0 = SNAT_IN2OUT_NEXT_DROP;
 616       goto out;
 617     }
 618
 619   if (PREDICT_FALSE(icmp0->type != ICMP4_echo_request &&
 620                     (icmp0->type != ICMP4_echo_reply || !is_addr_only) &&
 621                     !icmp_is_error_message (icmp0)))
 622     {
 623       b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
 624       next0 = SNAT_IN2OUT_NEXT_DROP;
 625       goto out;
 626     }
 627
 628 out:
 629   *p_value = sm0;
 630 out2:
 631   *p_proto = key0.protocol;
 632   *p_dont_translate = dont_translate;
 633   return next0;
 634 }
 635
 636 static inline u32 icmp_in2out (snat_main_t *sm,
 637                                vlib_buffer_t * b0,
 638                                ip4_header_t * ip0,
 639                                icmp46_header_t * icmp0,
 640                                u32 sw_if_index0,
 641                                u32 rx_fib_index0,
 642                                vlib_node_runtime_t * node,
 643                                u32 next0,
 644                                u32 thread_index,
 645                                void *d,
 646                                void *e)
 647 {
 648   snat_session_key_t sm0;
 649   u8 protocol;
 650   icmp_echo_header_t *echo0, *inner_echo0 = 0;
 651   ip4_header_t *inner_ip0;
 652   void *l4_header = 0;
 653   icmp46_header_t *inner_icmp0;
 654   u8 dont_translate;
 655   u32 new_addr0, old_addr0;
 656   u16 old_id0, new_id0;
 657   ip_csum_t sum0;
 658   u16 checksum0;
 659   u32 next0_tmp;
 660
 661   echo0 = (icmp_echo_header_t *)(icmp0+1);
 662
 663   next0_tmp = sm->icmp_match_in2out_cb(sm, node, thread_index, b0,
 664                                        &protocol, &sm0, &dont_translate, d, e);
 665   if (next0_tmp != ~0)
 666     next0 = next0_tmp;
 667   if (next0 == SNAT_IN2OUT_NEXT_DROP || dont_translate)
 668     goto out;
 669
 670   sum0 = ip_incremental_checksum (0, icmp0,
 671                                   ntohs(ip0->length) - ip4_header_bytes (ip0));
 672   checksum0 = ~ip_csum_fold (sum0);
 673   if (PREDICT_FALSE(checksum0 != 0 && checksum0 != 0xffff))
 674     {
 675       next0 = SNAT_IN2OUT_NEXT_DROP;
 676       goto out;
 677     }
 678
 679   old_addr0 = ip0->src_address.as_u32;
 680   new_addr0 = ip0->src_address.as_u32 = sm0.addr.as_u32;
 681   vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
 682
 683   sum0 = ip0->checksum;
 684   sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 685                          src_address /* changed member */);
 686   ip0->checksum = ip_csum_fold (sum0);
 687
 688   if (!icmp_is_error_message (icmp0))
 689     {
 690       new_id0 = sm0.port;
 691       if (PREDICT_FALSE(new_id0 != echo0->identifier))
 692         {
 693           old_id0 = echo0->identifier;
 694           new_id0 = sm0.port;
 695           echo0->identifier = new_id0;
 696
 697           sum0 = icmp0->checksum;
 698           sum0 = ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
 699                                  identifier);
 700           icmp0->checksum = ip_csum_fold (sum0);
 701         }
 702     }
 703   else
 704     {
 705       inner_ip0 = (ip4_header_t *)(echo0+1);
 706       l4_header = ip4_next_header (inner_ip0);
 707
 708       if (!ip4_header_checksum_is_valid (inner_ip0))
 709         {
 710           next0 = SNAT_IN2OUT_NEXT_DROP;
 711           goto out;
 712         }
 713
 714       old_addr0 = inner_ip0->dst_address.as_u32;
 715       inner_ip0->dst_address = sm0.addr;
 716       new_addr0 = inner_ip0->dst_address.as_u32;
 717
 718       sum0 = icmp0->checksum;
 719       sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 720                              dst_address /* changed member */);
 721       icmp0->checksum = ip_csum_fold (sum0);
 722
 723       switch (protocol)
 724         {
 725           case SNAT_PROTOCOL_ICMP:
 726             inner_icmp0 = (icmp46_header_t*)l4_header;
 727             inner_echo0 = (icmp_echo_header_t *)(inner_icmp0+1);
 728
 729             old_id0 = inner_echo0->identifier;
 730             new_id0 = sm0.port;
 731             inner_echo0->identifier = new_id0;
 732
 733             sum0 = icmp0->checksum;
 734             sum0 = ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
 735                                    identifier);
 736             icmp0->checksum = ip_csum_fold (sum0);
 737             break;
 738           case SNAT_PROTOCOL_UDP:
 739           case SNAT_PROTOCOL_TCP:
 740             old_id0 = ((tcp_udp_header_t*)l4_header)->dst_port;
 741             new_id0 = sm0.port;
 742             ((tcp_udp_header_t*)l4_header)->dst_port = new_id0;
 743
 744             sum0 = icmp0->checksum;
 745             sum0 = ip_csum_update (sum0, old_id0, new_id0, tcp_udp_header_t,
 746                                    dst_port);
 747             icmp0->checksum = ip_csum_fold (sum0);
 748             break;
 749           default:
 750             ASSERT(0);
 751         }
 752     }
 753
 754 out:
 755   return next0;
 756 }
 757
 758 /**
 759  * @brief Hairpinning
 760  *
 761  * Hairpinning allows two endpoints on the internal side of the NAT to
 762  * communicate even if they only use each other's external IP addresses
 763  * and ports.
 764  *
 765  * @param sm     SNAT main.
 766  * @param b0     Vlib buffer.
 767  * @param ip0    IP header.
 768  * @param udp0   UDP header.
 769  * @param tcp0   TCP header.
 770  * @param proto0 SNAT protocol.
 771  */
 772 static inline void
 773 snat_hairpinning (snat_main_t *sm,
 774                   vlib_buffer_t * b0,
 775                   ip4_header_t * ip0,
 776                   udp_header_t * udp0,
 777                   tcp_header_t * tcp0,
 778                   u32 proto0)
 779 {
 780   snat_session_key_t key0, sm0;
 781   snat_worker_key_t k0;
 782   snat_session_t * s0;
 783   clib_bihash_kv_8_8_t kv0, value0;
 784   ip_csum_t sum0;
 785   u32 new_dst_addr0 = 0, old_dst_addr0, ti = 0, si;
 786   u16 new_dst_port0, old_dst_port0;
 787
 788   key0.addr = ip0->dst_address;
 789   key0.port = udp0->dst_port;
 790   key0.protocol = proto0;
 791   key0.fib_index = sm->outside_fib_index;
 792   kv0.key = key0.as_u64;
 793
 794   /* Check if destination is in active sessions */
 795   if (clib_bihash_search_8_8 (&sm->out2in, &kv0, &value0))
 796     {
 797       /* or static mappings */
 798       if (!snat_static_mapping_match(sm, key0, &sm0, 1, 0))
 799         {
 800           new_dst_addr0 = sm0.addr.as_u32;
 801           new_dst_port0 = sm0.port;
 802           vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
 803         }
 804     }
 805   else
 806     {
 807       si = value0.value;
 808       if (sm->num_workers > 1)
 809         {
 810           k0.addr = ip0->dst_address;
 811           k0.port = udp0->dst_port;
 812           k0.fib_index = sm->outside_fib_index;
 813           kv0.key = k0.as_u64;
 814           if (clib_bihash_search_8_8 (&sm->worker_by_out, &kv0, &value0))
 815             ASSERT(0);
 816           else
 817             ti = value0.value;
 818         }
 819       else
 820         ti = sm->num_workers;
 821
 822       s0 = pool_elt_at_index (sm->per_thread_data[ti].sessions, si);
 823       new_dst_addr0 = s0->in2out.addr.as_u32;
 824       new_dst_port0 = s0->in2out.port;
 825       vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
 826     }
 827
 828   /* Destination is behind the same NAT, use internal address and port */
 829   if (new_dst_addr0)
 830     {
 831       old_dst_addr0 = ip0->dst_address.as_u32;
 832       ip0->dst_address.as_u32 = new_dst_addr0;
 833       sum0 = ip0->checksum;
 834       sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
 835                              ip4_header_t, dst_address);
 836       ip0->checksum = ip_csum_fold (sum0);
 837
 838       old_dst_port0 = tcp0->dst;
 839       if (PREDICT_TRUE(new_dst_port0 != old_dst_port0))
 840         {
 841           if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
 842             {
 843               tcp0->dst = new_dst_port0;
 844               sum0 = tcp0->checksum;
 845               sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
 846                                      ip4_header_t, dst_address);
 847               sum0 = ip_csum_update (sum0, old_dst_port0, new_dst_port0,
 848                                      ip4_header_t /* cheat */, length);
 849               tcp0->checksum = ip_csum_fold(sum0);
 850             }
 851           else
 852             {
 853               udp0->dst_port = new_dst_port0;
 854               udp0->checksum = 0;
 855             }
 856         }
 857       else
 858         {
 859           if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
 860             {
 861               sum0 = tcp0->checksum;
 862               sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
 863                                      ip4_header_t, dst_address);
 864               tcp0->checksum = ip_csum_fold(sum0);
 865             }
 866         }
 867     }
 868 }
 869
 870 static inline u32 icmp_in2out_slow_path (snat_main_t *sm,
 871                                          vlib_buffer_t * b0,
 872                                          ip4_header_t * ip0,
 873                                          icmp46_header_t * icmp0,
 874                                          u32 sw_if_index0,
 875                                          u32 rx_fib_index0,
 876                                          vlib_node_runtime_t * node,
 877                                          u32 next0,
 878                                          f64 now,
 879                                          u32 thread_index,
 880                                          snat_session_t ** p_s0)
 881 {
 882   snat_session_key_t key0, sm0;
 883   clib_bihash_kv_8_8_t kv0, value0;
 884   snat_worker_key_t k0;
 885   u32 new_dst_addr0 = 0, old_dst_addr0, si, ti = 0;
 886   ip_csum_t sum0;
 887
 888   next0 = icmp_in2out(sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
 889                       next0, thread_index, p_s0, 0);
 890   snat_session_t * s0 = *p_s0;
 891   if (PREDICT_TRUE(next0 != SNAT_IN2OUT_NEXT_DROP && s0))
 892     {
 893       /* Hairpinning */
 894       if (!icmp_is_error_message (icmp0))
 895         {
 896           icmp_echo_header_t *echo0 = (icmp_echo_header_t *)(icmp0+1);
 897           u16 icmp_id0 = echo0->identifier;
 898           key0.addr = ip0->dst_address;
 899           key0.port = icmp_id0;
 900           key0.protocol = SNAT_PROTOCOL_ICMP;
 901           key0.fib_index = sm->outside_fib_index;
 902           kv0.key = key0.as_u64;
 903
 904           /* Check if destination is in active sessions */
 905           if (clib_bihash_search_8_8 (&sm->out2in, &kv0, &value0))
 906             {
 907               /* or static mappings */
 908               if (!snat_static_mapping_match(sm, key0, &sm0, 1, 0))
 909                 {
 910                   new_dst_addr0 = sm0.addr.as_u32;
 911                   vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
 912                 }
 913             }
 914           else
 915             {
 916               si = value0.value;
 917               if (sm->num_workers > 1)
 918                 {
 919                   k0.addr = ip0->dst_address;
 920                   k0.port = icmp_id0;
 921                   k0.fib_index = sm->outside_fib_index;
 922                   kv0.key = k0.as_u64;
 923                   if (clib_bihash_search_8_8 (&sm->worker_by_out, &kv0, &value0))
 924                     ASSERT(0);
 925                   else
 926                     ti = value0.value;
 927                 }
 928               else
 929                 ti = sm->num_workers;
 930
 931               s0 = pool_elt_at_index (sm->per_thread_data[ti].sessions, si);
 932               new_dst_addr0 = s0->in2out.addr.as_u32;
 933               vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
 934               echo0->identifier = s0->in2out.port;
 935               sum0 = icmp0->checksum;
 936               sum0 = ip_csum_update (sum0, icmp_id0, s0->in2out.port,
 937                                      icmp_echo_header_t, identifier);
 938               icmp0->checksum = ip_csum_fold (sum0);
 939             }
 940
 941           /* Destination is behind the same NAT, use internal address and port */
 942           if (new_dst_addr0)
 943             {
 944               old_dst_addr0 = ip0->dst_address.as_u32;
 945               ip0->dst_address.as_u32 = new_dst_addr0;
 946               sum0 = ip0->checksum;
 947               sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
 948                                      ip4_header_t, dst_address);
 949               ip0->checksum = ip_csum_fold (sum0);
 950             }
 951         }
 952
 953       /* Accounting */
 954       s0->last_heard = now;
 955       s0->total_pkts++;
 956       s0->total_bytes += vlib_buffer_length_in_chain (sm->vlib_main, b0);
 957       /* Per-user LRU list maintenance for dynamic translations */
 958       if (!snat_is_session_static (s0))
 959         {
 960           clib_dlist_remove (sm->per_thread_data[thread_index].list_pool,
 961                              s0->per_user_index);
 962           clib_dlist_addtail (sm->per_thread_data[thread_index].list_pool,
 963                               s0->per_user_list_head_index,
 964                               s0->per_user_index);
 965         }
 966     }
 967   return next0;
 968 }
 969
 970 static inline uword
 971 snat_in2out_node_fn_inline (vlib_main_t * vm,
 972                             vlib_node_runtime_t * node,
 973                             vlib_frame_t * frame, int is_slow_path)
 974 {
 975   u32 n_left_from, * from, * to_next;
 976   snat_in2out_next_t next_index;
 977   u32 pkts_processed = 0;
 978   snat_main_t * sm = &snat_main;
 979   f64 now = vlib_time_now (vm);
 980   u32 stats_node_index;
 981   u32 thread_index = vlib_get_thread_index ();
 982
 983   stats_node_index = is_slow_path ? snat_in2out_slowpath_node.index :
 984     snat_in2out_node.index;
 985
 986   from = vlib_frame_vector_args (frame);
 987   n_left_from = frame->n_vectors;
 988   next_index = node->cached_next_index;
 989
 990   while (n_left_from > 0)
 991     {
 992       u32 n_left_to_next;
 993
 994       vlib_get_next_frame (vm, node, next_index,
 995                            to_next, n_left_to_next);
 996
 997       while (n_left_from >= 4 && n_left_to_next >= 2)
 998         {
 999           u32 bi0, bi1;
1000           vlib_buffer_t * b0, * b1;
1001           u32 next0, next1;
1002           u32 sw_if_index0, sw_if_index1;
1003           ip4_header_t * ip0, * ip1;
1004           ip_csum_t sum0, sum1;
1005           u32 new_addr0, old_addr0, new_addr1, old_addr1;
1006           u16 old_port0, new_port0, old_port1, new_port1;
1007           udp_header_t * udp0, * udp1;
1008           tcp_header_t * tcp0, * tcp1;
1009           icmp46_header_t * icmp0, * icmp1;
1010           snat_session_key_t key0, key1;
1011           u32 rx_fib_index0, rx_fib_index1;
1012           u32 proto0, proto1;
1013           snat_session_t * s0 = 0, * s1 = 0;
1014           clib_bihash_kv_8_8_t kv0, value0, kv1, value1;
1015
1016           /* Prefetch next iteration. */
1017           {
1018             vlib_buffer_t * p2, * p3;
1019
1020             p2 = vlib_get_buffer (vm, from[2]);
1021             p3 = vlib_get_buffer (vm, from[3]);
1022
1023             vlib_prefetch_buffer_header (p2, LOAD);
1024             vlib_prefetch_buffer_header (p3, LOAD);
1025
1026             CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE);
1027             CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE);
1028           }
1029
1030           /* speculatively enqueue b0 and b1 to the current next frame */
1031           to_next[0] = bi0 = from[0];
1032           to_next[1] = bi1 = from[1];
1033           from += 2;
1034           to_next += 2;
1035           n_left_from -= 2;
1036           n_left_to_next -= 2;
1037
1038           b0 = vlib_get_buffer (vm, bi0);
1039           b1 = vlib_get_buffer (vm, bi1);
1040
1041           ip0 = vlib_buffer_get_current (b0);
1042           udp0 = ip4_next_header (ip0);
1043           tcp0 = (tcp_header_t *) udp0;
1044           icmp0 = (icmp46_header_t *) udp0;
1045
1046           sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
1047           rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
1048                                    sw_if_index0);
1049
1050           next0 = next1 = SNAT_IN2OUT_NEXT_LOOKUP;
1051
1052           if (PREDICT_FALSE(ip0->ttl == 1))
1053             {
1054               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1055               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1056                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1057                                            0);
1058               next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
1059               goto trace00;
1060             }
1061
1062           proto0 = ip_proto_to_snat_proto (ip0->protocol);
1063
1064           /* Next configured feature, probably ip4-lookup */
1065           if (is_slow_path)
1066             {
1067               if (PREDICT_FALSE (proto0 == ~0))
1068                 goto trace00;
1069
1070               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1071                 {
1072                   next0 = icmp_in2out_slow_path
1073                     (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0,
1074                      node, next0, now, thread_index, &s0);
1075                   goto trace00;
1076                 }
1077             }
1078           else
1079             {
1080               if (PREDICT_FALSE (proto0 == ~0 || proto0 == SNAT_PROTOCOL_ICMP))
1081                 {
1082                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1083                   goto trace00;
1084                 }
1085             }
1086
1087           key0.addr = ip0->src_address;
1088           key0.port = udp0->src_port;
1089           key0.protocol = proto0;
1090           key0.fib_index = rx_fib_index0;
1091
1092           kv0.key = key0.as_u64;
1093
1094           if (PREDICT_FALSE (clib_bihash_search_8_8 (&sm->in2out, &kv0, &value0) != 0))
1095             {
1096               if (is_slow_path)
1097                 {
1098                   if (PREDICT_FALSE(snat_not_translate(sm, node, sw_if_index0, ip0,
1099                       proto0, rx_fib_index0)))
1100                     goto trace00;
1101
1102                   next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0,
1103                                      &s0, node, next0, thread_index);
1104                   if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
1105                     goto trace00;
1106                 }
1107               else
1108                 {
1109                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1110                   goto trace00;
1111                 }
1112             }
1113           else
1114             s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
1115                                     value0.value);
1116
1117           old_addr0 = ip0->src_address.as_u32;
1118           ip0->src_address = s0->out2in.addr;
1119           new_addr0 = ip0->src_address.as_u32;
1120           vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
1121
1122           sum0 = ip0->checksum;
1123           sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1124                                  ip4_header_t,
1125                                  src_address /* changed member */);
1126           ip0->checksum = ip_csum_fold (sum0);
1127
1128           if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
1129             {
1130               old_port0 = tcp0->src_port;
1131               tcp0->src_port = s0->out2in.port;
1132               new_port0 = tcp0->src_port;
1133
1134               sum0 = tcp0->checksum;
1135               sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1136                                      ip4_header_t,
1137                                      dst_address /* changed member */);
1138               sum0 = ip_csum_update (sum0, old_port0, new_port0,
1139                                      ip4_header_t /* cheat */,
1140                                      length /* changed member */);
1141               tcp0->checksum = ip_csum_fold(sum0);
1142             }
1143           else
1144             {
1145               old_port0 = udp0->src_port;
1146               udp0->src_port = s0->out2in.port;
1147               udp0->checksum = 0;
1148             }
1149
1150           /* Hairpinning */
1151           snat_hairpinning (sm, b0, ip0, udp0, tcp0, proto0);
1152
1153           /* Accounting */
1154           s0->last_heard = now;
1155           s0->total_pkts++;
1156           s0->total_bytes += vlib_buffer_length_in_chain (vm, b0);
1157           /* Per-user LRU list maintenance for dynamic translation */
1158           if (!snat_is_session_static (s0))
1159             {
1160               clib_dlist_remove (sm->per_thread_data[thread_index].list_pool,
1161                                  s0->per_user_index);
1162               clib_dlist_addtail (sm->per_thread_data[thread_index].list_pool,
1163                                   s0->per_user_list_head_index,
1164                                   s0->per_user_index);
1165             }
1166         trace00:
1167
1168           if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
1169                             && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1170             {
1171               snat_in2out_trace_t *t =
1172                  vlib_add_trace (vm, node, b0, sizeof (*t));
1173               t->is_slow_path = is_slow_path;
1174               t->sw_if_index = sw_if_index0;
1175               t->next_index = next0;
1176                   t->session_index = ~0;
1177               if (s0)
1178                 t->session_index = s0 - sm->per_thread_data[thread_index].sessions;
1179             }
1180
1181           pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
1182
1183           ip1 = vlib_buffer_get_current (b1);
1184           udp1 = ip4_next_header (ip1);
1185           tcp1 = (tcp_header_t *) udp1;
1186           icmp1 = (icmp46_header_t *) udp1;
1187
1188           sw_if_index1 = vnet_buffer(b1)->sw_if_index[VLIB_RX];
1189           rx_fib_index1 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
1190                                    sw_if_index1);
1191
1192           if (PREDICT_FALSE(ip1->ttl == 1))
1193             {
1194               vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1195               icmp4_error_set_vnet_buffer (b1, ICMP4_time_exceeded,
1196                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1197                                            0);
1198               next1 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
1199               goto trace01;
1200             }
1201
1202           proto1 = ip_proto_to_snat_proto (ip1->protocol);
1203
1204           /* Next configured feature, probably ip4-lookup */
1205           if (is_slow_path)
1206             {
1207               if (PREDICT_FALSE (proto1 == ~0))
1208                 goto trace01;
1209
1210               if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP))
1211                 {
1212                   next1 = icmp_in2out_slow_path
1213                     (sm, b1, ip1, icmp1, sw_if_index1, rx_fib_index1, node,
1214                      next1, now, thread_index, &s1);
1215                   goto trace01;
1216                 }
1217             }
1218           else
1219             {
1220               if (PREDICT_FALSE (proto1 == ~0 || proto1 == SNAT_PROTOCOL_ICMP))
1221                 {
1222                   next1 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1223                   goto trace01;
1224                 }
1225             }
1226
1227           key1.addr = ip1->src_address;
1228           key1.port = udp1->src_port;
1229           key1.protocol = proto1;
1230           key1.fib_index = rx_fib_index1;
1231
1232           kv1.key = key1.as_u64;
1233
1234             if (PREDICT_FALSE(clib_bihash_search_8_8 (&sm->in2out, &kv1, &value1) != 0))
1235             {
1236               if (is_slow_path)
1237                 {
1238                   if (PREDICT_FALSE(snat_not_translate(sm, node, sw_if_index1, ip1,
1239                       proto1, rx_fib_index1)))
1240                     goto trace01;
1241
1242                   next1 = slow_path (sm, b1, ip1, rx_fib_index1, &key1,
1243                                      &s1, node, next1, thread_index);
1244                   if (PREDICT_FALSE (next1 == SNAT_IN2OUT_NEXT_DROP))
1245                     goto trace01;
1246                 }
1247               else
1248                 {
1249                   next1 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1250                   goto trace01;
1251                 }
1252             }
1253           else
1254             s1 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
1255                                     value1.value);
1256
1257           old_addr1 = ip1->src_address.as_u32;
1258           ip1->src_address = s1->out2in.addr;
1259           new_addr1 = ip1->src_address.as_u32;
1260           vnet_buffer(b1)->sw_if_index[VLIB_TX] = s1->out2in.fib_index;
1261
1262           sum1 = ip1->checksum;
1263           sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
1264                                  ip4_header_t,
1265                                  src_address /* changed member */);
1266           ip1->checksum = ip_csum_fold (sum1);
1267
1268           if (PREDICT_TRUE(proto1 == SNAT_PROTOCOL_TCP))
1269             {
1270               old_port1 = tcp1->src_port;
1271               tcp1->src_port = s1->out2in.port;
1272               new_port1 = tcp1->src_port;
1273
1274               sum1 = tcp1->checksum;
1275               sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
1276                                      ip4_header_t,
1277                                      dst_address /* changed member */);
1278               sum1 = ip_csum_update (sum1, old_port1, new_port1,
1279                                      ip4_header_t /* cheat */,
1280                                      length /* changed member */);
1281               tcp1->checksum = ip_csum_fold(sum1);
1282             }
1283           else
1284             {
1285               old_port1 = udp1->src_port;
1286               udp1->src_port = s1->out2in.port;
1287               udp1->checksum = 0;
1288             }
1289
1290           /* Hairpinning */
1291           snat_hairpinning (sm, b1, ip1, udp1, tcp1, proto1);
1292
1293           /* Accounting */
1294           s1->last_heard = now;
1295           s1->total_pkts++;
1296           s1->total_bytes += vlib_buffer_length_in_chain (vm, b1);
1297           /* Per-user LRU list maintenance for dynamic translation */
1298           if (!snat_is_session_static (s1))
1299             {
1300               clib_dlist_remove (sm->per_thread_data[thread_index].list_pool,
1301                                  s1->per_user_index);
1302               clib_dlist_addtail (sm->per_thread_data[thread_index].list_pool,
1303                                   s1->per_user_list_head_index,
1304                                   s1->per_user_index);
1305             }
1306         trace01:
1307
1308           if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
1309                             && (b1->flags & VLIB_BUFFER_IS_TRACED)))
1310             {
1311               snat_in2out_trace_t *t =
1312                  vlib_add_trace (vm, node, b1, sizeof (*t));
1313               t->sw_if_index = sw_if_index1;
1314               t->next_index = next1;
1315               t->session_index = ~0;
1316               if (s1)
1317                 t->session_index = s1 - sm->per_thread_data[thread_index].sessions;
1318             }
1319
1320           pkts_processed += next1 != SNAT_IN2OUT_NEXT_DROP;
1321
1322           /* verify speculative enqueues, maybe switch current next frame */
1323           vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
1324                                            to_next, n_left_to_next,
1325                                            bi0, bi1, next0, next1);
1326         }
1327
1328       while (n_left_from > 0 && n_left_to_next > 0)
1329         {
1330           u32 bi0;
1331           vlib_buffer_t * b0;
1332           u32 next0;
1333           u32 sw_if_index0;
1334           ip4_header_t * ip0;
1335           ip_csum_t sum0;
1336           u32 new_addr0, old_addr0;
1337           u16 old_port0, new_port0;
1338           udp_header_t * udp0;
1339           tcp_header_t * tcp0;
1340           icmp46_header_t * icmp0;
1341           snat_session_key_t key0;
1342           u32 rx_fib_index0;
1343           u32 proto0;
1344           snat_session_t * s0 = 0;
1345           clib_bihash_kv_8_8_t kv0, value0;
1346
1347           /* speculatively enqueue b0 to the current next frame */
1348           bi0 = from[0];
1349           to_next[0] = bi0;
1350           from += 1;
1351           to_next += 1;
1352           n_left_from -= 1;
1353           n_left_to_next -= 1;
1354
1355           b0 = vlib_get_buffer (vm, bi0);
1356           next0 = SNAT_IN2OUT_NEXT_LOOKUP;
1357
1358           ip0 = vlib_buffer_get_current (b0);
1359           udp0 = ip4_next_header (ip0);
1360           tcp0 = (tcp_header_t *) udp0;
1361           icmp0 = (icmp46_header_t *) udp0;
1362
1363           sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
1364           rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
1365                                    sw_if_index0);
1366
1367           if (PREDICT_FALSE(ip0->ttl == 1))
1368             {
1369               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1370               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1371                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1372                                            0);
1373               next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
1374               goto trace0;
1375             }
1376
1377           proto0 = ip_proto_to_snat_proto (ip0->protocol);
1378
1379           /* Next configured feature, probably ip4-lookup */
1380           if (is_slow_path)
1381             {
1382               if (PREDICT_FALSE (proto0 == ~0))
1383                 goto trace0;
1384
1385               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1386                 {
1387                   next0 = icmp_in2out_slow_path
1388                     (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1389                      next0, now, thread_index, &s0);
1390                   goto trace0;
1391                 }
1392             }
1393           else
1394             {
1395               if (PREDICT_FALSE (proto0 == ~0 || proto0 == SNAT_PROTOCOL_ICMP))
1396                 {
1397                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1398                   goto trace0;
1399                 }
1400             }
1401
1402           key0.addr = ip0->src_address;
1403           key0.port = udp0->src_port;
1404           key0.protocol = proto0;
1405           key0.fib_index = rx_fib_index0;
1406
1407           kv0.key = key0.as_u64;
1408
1409           if (clib_bihash_search_8_8 (&sm->in2out, &kv0, &value0))
1410             {
1411               if (is_slow_path)
1412                 {
1413                   if (PREDICT_FALSE(snat_not_translate(sm, node, sw_if_index0, ip0,
1414                       proto0, rx_fib_index0)))
1415                     goto trace0;
1416
1417                   next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0,
1418                                      &s0, node, next0, thread_index);
1419
1420                   if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
1421                     goto trace0;
1422                 }
1423               else
1424                 {
1425                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1426                   goto trace0;
1427                 }
1428             }
1429           else
1430             s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
1431                                     value0.value);
1432
1433           old_addr0 = ip0->src_address.as_u32;
1434           ip0->src_address = s0->out2in.addr;
1435           new_addr0 = ip0->src_address.as_u32;
1436           vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
1437
1438           sum0 = ip0->checksum;
1439           sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1440                                  ip4_header_t,
1441                                  src_address /* changed member */);
1442           ip0->checksum = ip_csum_fold (sum0);
1443
1444           if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
1445             {
1446               old_port0 = tcp0->src_port;
1447               tcp0->src_port = s0->out2in.port;
1448               new_port0 = tcp0->src_port;
1449
1450               sum0 = tcp0->checksum;
1451               sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1452                                      ip4_header_t,
1453                                      dst_address /* changed member */);
1454               sum0 = ip_csum_update (sum0, old_port0, new_port0,
1455                                      ip4_header_t /* cheat */,
1456                                      length /* changed member */);
1457               tcp0->checksum = ip_csum_fold(sum0);
1458             }
1459           else
1460             {
1461               old_port0 = udp0->src_port;
1462               udp0->src_port = s0->out2in.port;
1463               udp0->checksum = 0;
1464             }
1465
1466           /* Hairpinning */
1467           snat_hairpinning (sm, b0, ip0, udp0, tcp0, proto0);
1468
1469           /* Accounting */
1470           s0->last_heard = now;
1471           s0->total_pkts++;
1472           s0->total_bytes += vlib_buffer_length_in_chain (vm, b0);
1473           /* Per-user LRU list maintenance for dynamic translation */
1474           if (!snat_is_session_static (s0))
1475             {
1476               clib_dlist_remove (sm->per_thread_data[thread_index].list_pool,
1477                                  s0->per_user_index);
1478               clib_dlist_addtail (sm->per_thread_data[thread_index].list_pool,
1479                                   s0->per_user_list_head_index,
1480                                   s0->per_user_index);
1481             }
1482
1483         trace0:
1484           if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
1485                             && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1486             {
1487               snat_in2out_trace_t *t =
1488                  vlib_add_trace (vm, node, b0, sizeof (*t));
1489               t->is_slow_path = is_slow_path;
1490               t->sw_if_index = sw_if_index0;
1491               t->next_index = next0;
1492                   t->session_index = ~0;
1493               if (s0)
1494                 t->session_index = s0 - sm->per_thread_data[thread_index].sessions;
1495             }
1496
1497           pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
1498
1499           /* verify speculative enqueue, maybe switch current next frame */
1500           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1501                                            to_next, n_left_to_next,
1502                                            bi0, next0);
1503         }
1504
1505       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1506     }
1507
1508   vlib_node_increment_counter (vm, stats_node_index,
1509                                SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
1510                                pkts_processed);
1511   return frame->n_vectors;
1512 }
1513
1514 static uword
1515 snat_in2out_fast_path_fn (vlib_main_t * vm,
1516                           vlib_node_runtime_t * node,
1517                           vlib_frame_t * frame)
1518 {
1519   return snat_in2out_node_fn_inline (vm, node, frame, 0 /* is_slow_path */);
1520 }
1521
1522 VLIB_REGISTER_NODE (snat_in2out_node) = {
1523   .function = snat_in2out_fast_path_fn,
1524   .name = "snat-in2out",
1525   .vector_size = sizeof (u32),
1526   .format_trace = format_snat_in2out_trace,
1527   .type = VLIB_NODE_TYPE_INTERNAL,
1528
1529   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
1530   .error_strings = snat_in2out_error_strings,
1531
1532   .runtime_data_bytes = sizeof (snat_runtime_t),
1533
1534   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
1535
1536   /* edit / add dispositions here */
1537   .next_nodes = {
1538     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
1539     [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
1540     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "snat-in2out-slowpath",
1541     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1542   },
1543 };
1544
1545 VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_node, snat_in2out_fast_path_fn);
1546
1547 static uword
1548 snat_in2out_slow_path_fn (vlib_main_t * vm,
1549                           vlib_node_runtime_t * node,
1550                           vlib_frame_t * frame)
1551 {
1552   return snat_in2out_node_fn_inline (vm, node, frame, 1 /* is_slow_path */);
1553 }
1554
1555 VLIB_REGISTER_NODE (snat_in2out_slowpath_node) = {
1556   .function = snat_in2out_slow_path_fn,
1557   .name = "snat-in2out-slowpath",
1558   .vector_size = sizeof (u32),
1559   .format_trace = format_snat_in2out_trace,
1560   .type = VLIB_NODE_TYPE_INTERNAL,
1561
1562   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
1563   .error_strings = snat_in2out_error_strings,
1564
1565   .runtime_data_bytes = sizeof (snat_runtime_t),
1566
1567   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
1568
1569   /* edit / add dispositions here */
1570   .next_nodes = {
1571     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
1572     [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
1573     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "snat-in2out-slowpath",
1574     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1575   },
1576 };
1577
1578 VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_slowpath_node, snat_in2out_slow_path_fn);
1579
1580 /**************************/
1581 /*** deterministic mode ***/
1582 /**************************/
1583 static uword
1584 snat_det_in2out_node_fn (vlib_main_t * vm,
1585                          vlib_node_runtime_t * node,
1586                          vlib_frame_t * frame)
1587 {
1588   u32 n_left_from, * from, * to_next;
1589   snat_in2out_next_t next_index;
1590   u32 pkts_processed = 0;
1591   snat_main_t * sm = &snat_main;
1592   u32 now = (u32) vlib_time_now (vm);
1593   u32 thread_index = vlib_get_thread_index ();
1594
1595   from = vlib_frame_vector_args (frame);
1596   n_left_from = frame->n_vectors;
1597   next_index = node->cached_next_index;
1598
1599   while (n_left_from > 0)
1600     {
1601       u32 n_left_to_next;
1602
1603       vlib_get_next_frame (vm, node, next_index,
1604                            to_next, n_left_to_next);
1605
1606       while (n_left_from >= 4 && n_left_to_next >= 2)
1607         {
1608           u32 bi0, bi1;
1609           vlib_buffer_t * b0, * b1;
1610           u32 next0, next1;
1611           u32 sw_if_index0, sw_if_index1;
1612           ip4_header_t * ip0, * ip1;
1613           ip_csum_t sum0, sum1;
1614           ip4_address_t new_addr0, old_addr0, new_addr1, old_addr1;
1615           u16 old_port0, new_port0, lo_port0, i0;
1616           u16 old_port1, new_port1, lo_port1, i1;
1617           udp_header_t * udp0, * udp1;
1618           tcp_header_t * tcp0, * tcp1;
1619           u32 proto0, proto1;
1620           snat_det_out_key_t key0, key1;
1621           snat_det_map_t * dm0, * dm1;
1622           snat_det_session_t * ses0 = 0, * ses1 = 0;
1623           u32 rx_fib_index0, rx_fib_index1;
1624           icmp46_header_t * icmp0, * icmp1;
1625
1626           /* Prefetch next iteration. */
1627           {
1628             vlib_buffer_t * p2, * p3;
1629
1630             p2 = vlib_get_buffer (vm, from[2]);
1631             p3 = vlib_get_buffer (vm, from[3]);
1632
1633             vlib_prefetch_buffer_header (p2, LOAD);
1634             vlib_prefetch_buffer_header (p3, LOAD);
1635
1636             CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE);
1637             CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE);
1638           }
1639
1640           /* speculatively enqueue b0 and b1 to the current next frame */
1641           to_next[0] = bi0 = from[0];
1642           to_next[1] = bi1 = from[1];
1643           from += 2;
1644           to_next += 2;
1645           n_left_from -= 2;
1646           n_left_to_next -= 2;
1647
1648           b0 = vlib_get_buffer (vm, bi0);
1649           b1 = vlib_get_buffer (vm, bi1);
1650
1651           next0 = SNAT_IN2OUT_NEXT_LOOKUP;
1652           next1 = SNAT_IN2OUT_NEXT_LOOKUP;
1653
1654           ip0 = vlib_buffer_get_current (b0);
1655           udp0 = ip4_next_header (ip0);
1656           tcp0 = (tcp_header_t *) udp0;
1657
1658           sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
1659
1660           if (PREDICT_FALSE(ip0->ttl == 1))
1661             {
1662               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1663               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1664                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1665                                            0);
1666               next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
1667               goto trace0;
1668             }
1669
1670           proto0 = ip_proto_to_snat_proto (ip0->protocol);
1671
1672           if (PREDICT_FALSE(proto0 == SNAT_PROTOCOL_ICMP))
1673             {
1674               rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index(sw_if_index0);
1675               icmp0 = (icmp46_header_t *) udp0;
1676
1677               next0 = icmp_in2out(sm, b0, ip0, icmp0, sw_if_index0,
1678                                   rx_fib_index0, node, next0, thread_index,
1679                                   &ses0, &dm0);
1680               goto trace0;
1681             }
1682
1683           dm0 = snat_det_map_by_user(sm, &ip0->src_address);
1684           if (PREDICT_FALSE(!dm0))
1685             {
1686               clib_warning("no match for internal host %U",
1687                            format_ip4_address, &ip0->src_address);
1688               next0 = SNAT_IN2OUT_NEXT_DROP;
1689               b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
1690               goto trace0;
1691             }
1692
1693           snat_det_forward(dm0, &ip0->src_address, &new_addr0, &lo_port0);
1694
1695           key0.ext_host_addr = ip0->dst_address;
1696           key0.ext_host_port = tcp0->dst;
1697
1698           ses0 = snat_det_find_ses_by_in(dm0, &ip0->src_address, tcp0->src, key0);
1699           if (PREDICT_FALSE(!ses0))
1700             {
1701               for (i0 = 0; i0 < dm0->ports_per_host; i0++)
1702                 {
1703                   key0.out_port = clib_host_to_net_u16 (lo_port0 +
1704                     ((i0 + clib_net_to_host_u16 (tcp0->src)) % dm0->ports_per_host));
1705
1706                   if (snat_det_get_ses_by_out (dm0, &ip0->src_address, key0.as_u64))
1707                     continue;
1708
1709                   ses0 = snat_det_ses_create(dm0, &ip0->src_address, tcp0->src, &key0);
1710                   break;
1711                 }
1712               if (PREDICT_FALSE(!ses0))
1713                 {
1714                   /* too many sessions for user, send ICMP error packet */
1715
1716                   vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1717                   icmp4_error_set_vnet_buffer (b0, ICMP4_destination_unreachable,
1718                                                ICMP4_destination_unreachable_destination_unreachable_host,
1719                                                0);
1720                   next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
1721                   goto trace0;
1722                 }
1723             }
1724
1725           new_port0 = ses0->out.out_port;
1726
1727           old_addr0.as_u32 = ip0->src_address.as_u32;
1728           ip0->src_address.as_u32 = new_addr0.as_u32;
1729           vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm->outside_fib_index;
1730
1731           sum0 = ip0->checksum;
1732           sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32,
1733                                  ip4_header_t,
1734                                  src_address /* changed member */);
1735           ip0->checksum = ip_csum_fold (sum0);
1736
1737           if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
1738             {
1739               if (tcp0->flags & TCP_FLAG_SYN)
1740                 ses0->state = SNAT_SESSION_TCP_SYN_SENT;
1741               else if (tcp0->flags & TCP_FLAG_ACK && ses0->state == SNAT_SESSION_TCP_SYN_SENT)
1742                 ses0->state = SNAT_SESSION_TCP_ESTABLISHED;
1743               else if (tcp0->flags & TCP_FLAG_FIN && ses0->state == SNAT_SESSION_TCP_ESTABLISHED)
1744                 ses0->state = SNAT_SESSION_TCP_FIN_WAIT;
1745               else if (tcp0->flags & TCP_FLAG_ACK && ses0->state == SNAT_SESSION_TCP_FIN_WAIT)
1746                 snat_det_ses_close(dm0, ses0);
1747               else if (tcp0->flags & TCP_FLAG_FIN && ses0->state == SNAT_SESSION_TCP_CLOSE_WAIT)
1748                 ses0->state = SNAT_SESSION_TCP_LAST_ACK;
1749               else if (tcp0->flags == 0 && ses0->state == SNAT_SESSION_UNKNOWN)
1750                 ses0->state = SNAT_SESSION_TCP_ESTABLISHED;
1751
1752               old_port0 = tcp0->src;
1753               tcp0->src = new_port0;
1754
1755               sum0 = tcp0->checksum;
1756               sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32,
1757                                      ip4_header_t,
1758                                      dst_address /* changed member */);
1759               sum0 = ip_csum_update (sum0, old_port0, new_port0,
1760                                      ip4_header_t /* cheat */,
1761                                      length /* changed member */);
1762               tcp0->checksum = ip_csum_fold(sum0);
1763             }
1764           else
1765             {
1766               ses0->state = SNAT_SESSION_UDP_ACTIVE;
1767               old_port0 = udp0->src_port;
1768               udp0->src_port = new_port0;
1769               udp0->checksum = 0;
1770             }
1771
1772           switch(ses0->state)
1773             {
1774             case SNAT_SESSION_UDP_ACTIVE:
1775                 ses0->expire = now + sm->udp_timeout;
1776                 break;
1777             case SNAT_SESSION_TCP_SYN_SENT:
1778             case SNAT_SESSION_TCP_FIN_WAIT:
1779             case SNAT_SESSION_TCP_CLOSE_WAIT:
1780             case SNAT_SESSION_TCP_LAST_ACK:
1781                 ses0->expire = now + sm->tcp_transitory_timeout;
1782                 break;
1783             case SNAT_SESSION_TCP_ESTABLISHED:
1784                 ses0->expire = now + sm->tcp_established_timeout;
1785                 break;
1786             }
1787
1788         trace0:
1789           if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
1790                             && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1791             {
1792               snat_in2out_trace_t *t =
1793                  vlib_add_trace (vm, node, b0, sizeof (*t));
1794               t->is_slow_path = 0;
1795               t->sw_if_index = sw_if_index0;
1796               t->next_index = next0;
1797               t->session_index = ~0;
1798               if (ses0)
1799                 t->session_index = ses0 - dm0->sessions;
1800             }
1801
1802           pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
1803
1804           ip1 = vlib_buffer_get_current (b1);
1805           udp1 = ip4_next_header (ip1);
1806           tcp1 = (tcp_header_t *) udp1;
1807
1808           sw_if_index1 = vnet_buffer(b1)->sw_if_index[VLIB_RX];
1809
1810           if (PREDICT_FALSE(ip1->ttl == 1))
1811             {
1812               vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1813               icmp4_error_set_vnet_buffer (b1, ICMP4_time_exceeded,
1814                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1815                                            0);
1816               next1 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
1817               goto trace1;
1818             }
1819
1820           proto1 = ip_proto_to_snat_proto (ip1->protocol);
1821
1822           if (PREDICT_FALSE(proto1 == SNAT_PROTOCOL_ICMP))
1823             {
1824               rx_fib_index1 = ip4_fib_table_get_index_for_sw_if_index(sw_if_index1);
1825               icmp1 = (icmp46_header_t *) udp1;
1826
1827               next1 = icmp_in2out(sm, b1, ip1, icmp1, sw_if_index1,
1828                                   rx_fib_index1, node, next1, thread_index,
1829                                   &ses1, &dm1);
1830               goto trace1;
1831             }
1832
1833           dm1 = snat_det_map_by_user(sm, &ip1->src_address);
1834           if (PREDICT_FALSE(!dm1))
1835             {
1836               clib_warning("no match for internal host %U",
1837                            format_ip4_address, &ip0->src_address);
1838               next1 = SNAT_IN2OUT_NEXT_DROP;
1839               b1->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
1840               goto trace1;
1841             }
1842
1843           snat_det_forward(dm1, &ip1->src_address, &new_addr1, &lo_port1);
1844
1845           key1.ext_host_addr = ip1->dst_address;
1846           key1.ext_host_port = tcp1->dst;
1847
1848           ses1 = snat_det_find_ses_by_in(dm1, &ip1->src_address, tcp1->src, key1);
1849           if (PREDICT_FALSE(!ses1))
1850             {
1851               for (i1 = 0; i1 < dm1->ports_per_host; i1++)
1852                 {
1853                   key1.out_port = clib_host_to_net_u16 (lo_port1 +
1854                     ((i1 + clib_net_to_host_u16 (tcp1->src)) % dm1->ports_per_host));
1855
1856                   if (snat_det_get_ses_by_out (dm1, &ip1->src_address, key1.as_u64))
1857                     continue;
1858
1859                   ses1 = snat_det_ses_create(dm1, &ip1->src_address, tcp1->src, &key1);
1860                   break;
1861                 }
1862               if (PREDICT_FALSE(!ses1))
1863                 {
1864                   /* too many sessions for user, send ICMP error packet */
1865
1866                   vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1867                   icmp4_error_set_vnet_buffer (b1, ICMP4_destination_unreachable,
1868                                                ICMP4_destination_unreachable_destination_unreachable_host,
1869                                                0);
1870                   next1 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
1871                   goto trace1;
1872                 }
1873             }
1874
1875           new_port1 = ses1->out.out_port;
1876
1877           old_addr1.as_u32 = ip1->src_address.as_u32;
1878           ip1->src_address.as_u32 = new_addr1.as_u32;
1879           vnet_buffer(b1)->sw_if_index[VLIB_TX] = sm->outside_fib_index;
1880
1881           sum1 = ip1->checksum;
1882           sum1 = ip_csum_update (sum1, old_addr1.as_u32, new_addr1.as_u32,
1883                                  ip4_header_t,
1884                                  src_address /* changed member */);
1885           ip1->checksum = ip_csum_fold (sum1);
1886
1887           if (PREDICT_TRUE(proto1 == SNAT_PROTOCOL_TCP))
1888             {
1889               if (tcp1->flags & TCP_FLAG_SYN)
1890                 ses1->state = SNAT_SESSION_TCP_SYN_SENT;
1891               else if (tcp1->flags & TCP_FLAG_ACK && ses1->state == SNAT_SESSION_TCP_SYN_SENT)
1892                 ses1->state = SNAT_SESSION_TCP_ESTABLISHED;
1893               else if (tcp1->flags & TCP_FLAG_FIN && ses1->state == SNAT_SESSION_TCP_ESTABLISHED)
1894                 ses1->state = SNAT_SESSION_TCP_FIN_WAIT;
1895               else if (tcp1->flags & TCP_FLAG_ACK && ses1->state == SNAT_SESSION_TCP_FIN_WAIT)
1896                 snat_det_ses_close(dm1, ses1);
1897               else if (tcp1->flags & TCP_FLAG_FIN && ses1->state == SNAT_SESSION_TCP_CLOSE_WAIT)
1898                 ses1->state = SNAT_SESSION_TCP_LAST_ACK;
1899               else if (tcp1->flags == 0 && ses1->state == SNAT_SESSION_UNKNOWN)
1900                 ses1->state = SNAT_SESSION_TCP_ESTABLISHED;
1901
1902               old_port1 = tcp1->src;
1903               tcp1->src = new_port1;
1904
1905               sum1 = tcp1->checksum;
1906               sum1 = ip_csum_update (sum1, old_addr1.as_u32, new_addr1.as_u32,
1907                                      ip4_header_t,
1908                                      dst_address /* changed member */);
1909               sum1 = ip_csum_update (sum1, old_port1, new_port1,
1910                                      ip4_header_t /* cheat */,
1911                                      length /* changed member */);
1912               tcp1->checksum = ip_csum_fold(sum1);
1913             }
1914           else
1915             {
1916               ses1->state = SNAT_SESSION_UDP_ACTIVE;
1917               old_port1 = udp1->src_port;
1918               udp1->src_port = new_port1;
1919               udp1->checksum = 0;
1920             }
1921
1922           switch(ses1->state)
1923             {
1924             case SNAT_SESSION_UDP_ACTIVE:
1925                 ses1->expire = now + sm->udp_timeout;
1926                 break;
1927             case SNAT_SESSION_TCP_SYN_SENT:
1928             case SNAT_SESSION_TCP_FIN_WAIT:
1929             case SNAT_SESSION_TCP_CLOSE_WAIT:
1930             case SNAT_SESSION_TCP_LAST_ACK:
1931                 ses1->expire = now + sm->tcp_transitory_timeout;
1932                 break;
1933             case SNAT_SESSION_TCP_ESTABLISHED:
1934                 ses1->expire = now + sm->tcp_established_timeout;
1935                 break;
1936             }
1937
1938         trace1:
1939           if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
1940                             && (b1->flags & VLIB_BUFFER_IS_TRACED)))
1941             {
1942               snat_in2out_trace_t *t =
1943                  vlib_add_trace (vm, node, b1, sizeof (*t));
1944               t->is_slow_path = 0;
1945               t->sw_if_index = sw_if_index1;
1946               t->next_index = next1;
1947               t->session_index = ~0;
1948               if (ses1)
1949                 t->session_index = ses1 - dm1->sessions;
1950             }
1951
1952           pkts_processed += next1 != SNAT_IN2OUT_NEXT_DROP;
1953
1954           /* verify speculative enqueues, maybe switch current next frame */
1955           vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
1956                                            to_next, n_left_to_next,
1957                                            bi0, bi1, next0, next1);
1958          }
1959
1960       while (n_left_from > 0 && n_left_to_next > 0)
1961         {
1962           u32 bi0;
1963           vlib_buffer_t * b0;
1964           u32 next0;
1965           u32 sw_if_index0;
1966           ip4_header_t * ip0;
1967           ip_csum_t sum0;
1968           ip4_address_t new_addr0, old_addr0;
1969           u16 old_port0, new_port0, lo_port0, i0;
1970           udp_header_t * udp0;
1971           tcp_header_t * tcp0;
1972           u32 proto0;
1973           snat_det_out_key_t key0;
1974           snat_det_map_t * dm0;
1975           snat_det_session_t * ses0 = 0;
1976           u32 rx_fib_index0;
1977           icmp46_header_t * icmp0;
1978
1979           /* speculatively enqueue b0 to the current next frame */
1980           bi0 = from[0];
1981           to_next[0] = bi0;
1982           from += 1;
1983           to_next += 1;
1984           n_left_from -= 1;
1985           n_left_to_next -= 1;
1986
1987           b0 = vlib_get_buffer (vm, bi0);
1988           next0 = SNAT_IN2OUT_NEXT_LOOKUP;
1989
1990           ip0 = vlib_buffer_get_current (b0);
1991           udp0 = ip4_next_header (ip0);
1992           tcp0 = (tcp_header_t *) udp0;
1993
1994           sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
1995
1996           if (PREDICT_FALSE(ip0->ttl == 1))
1997             {
1998               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1999               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
2000                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
2001                                            0);
2002               next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
2003               goto trace00;
2004             }
2005
2006           proto0 = ip_proto_to_snat_proto (ip0->protocol);
2007
2008           if (PREDICT_FALSE(proto0 == SNAT_PROTOCOL_ICMP))
2009             {
2010               rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index(sw_if_index0);
2011               icmp0 = (icmp46_header_t *) udp0;
2012
2013               next0 = icmp_in2out(sm, b0, ip0, icmp0, sw_if_index0,
2014                                   rx_fib_index0, node, next0, thread_index,
2015                                   &ses0, &dm0);
2016               goto trace00;
2017             }
2018
2019           dm0 = snat_det_map_by_user(sm, &ip0->src_address);
2020           if (PREDICT_FALSE(!dm0))
2021             {
2022               clib_warning("no match for internal host %U",
2023                            format_ip4_address, &ip0->src_address);
2024               next0 = SNAT_IN2OUT_NEXT_DROP;
2025               b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
2026               goto trace00;
2027             }
2028
2029           snat_det_forward(dm0, &ip0->src_address, &new_addr0, &lo_port0);
2030
2031           key0.ext_host_addr = ip0->dst_address;
2032           key0.ext_host_port = tcp0->dst;
2033
2034           ses0 = snat_det_find_ses_by_in(dm0, &ip0->src_address, tcp0->src, key0);
2035           if (PREDICT_FALSE(!ses0))
2036             {
2037               for (i0 = 0; i0 < dm0->ports_per_host; i0++)
2038                 {
2039                   key0.out_port = clib_host_to_net_u16 (lo_port0 +
2040                     ((i0 + clib_net_to_host_u16 (tcp0->src)) % dm0->ports_per_host));
2041
2042                   if (snat_det_get_ses_by_out (dm0, &ip0->src_address, key0.as_u64))
2043                     continue;
2044
2045                   ses0 = snat_det_ses_create(dm0, &ip0->src_address, tcp0->src, &key0);
2046                   break;
2047                 }
2048               if (PREDICT_FALSE(!ses0))
2049                 {
2050                   /* too many sessions for user, send ICMP error packet */
2051
2052                   vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
2053                   icmp4_error_set_vnet_buffer (b0, ICMP4_destination_unreachable,
2054                                                ICMP4_destination_unreachable_destination_unreachable_host,
2055                                                0);
2056                   next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
2057                   goto trace00;
2058                 }
2059             }
2060
2061           new_port0 = ses0->out.out_port;
2062
2063           old_addr0.as_u32 = ip0->src_address.as_u32;
2064           ip0->src_address.as_u32 = new_addr0.as_u32;
2065           vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm->outside_fib_index;
2066
2067           sum0 = ip0->checksum;
2068           sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32,
2069                                  ip4_header_t,
2070                                  src_address /* changed member */);
2071           ip0->checksum = ip_csum_fold (sum0);
2072
2073           if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
2074             {
2075               if (tcp0->flags & TCP_FLAG_SYN)
2076                 ses0->state = SNAT_SESSION_TCP_SYN_SENT;
2077               else if (tcp0->flags & TCP_FLAG_ACK && ses0->state == SNAT_SESSION_TCP_SYN_SENT)
2078                 ses0->state = SNAT_SESSION_TCP_ESTABLISHED;
2079               else if (tcp0->flags & TCP_FLAG_FIN && ses0->state == SNAT_SESSION_TCP_ESTABLISHED)
2080                 ses0->state = SNAT_SESSION_TCP_FIN_WAIT;
2081               else if (tcp0->flags & TCP_FLAG_ACK && ses0->state == SNAT_SESSION_TCP_FIN_WAIT)
2082                 snat_det_ses_close(dm0, ses0);
2083               else if (tcp0->flags & TCP_FLAG_FIN && ses0->state == SNAT_SESSION_TCP_CLOSE_WAIT)
2084                 ses0->state = SNAT_SESSION_TCP_LAST_ACK;
2085               else if (tcp0->flags == 0 && ses0->state == SNAT_SESSION_UNKNOWN)
2086                 ses0->state = SNAT_SESSION_TCP_ESTABLISHED;
2087
2088               old_port0 = tcp0->src;
2089               tcp0->src = new_port0;
2090
2091               sum0 = tcp0->checksum;
2092               sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32,
2093                                      ip4_header_t,
2094                                      dst_address /* changed member */);
2095               sum0 = ip_csum_update (sum0, old_port0, new_port0,
2096                                      ip4_header_t /* cheat */,
2097                                      length /* changed member */);
2098               tcp0->checksum = ip_csum_fold(sum0);
2099             }
2100           else
2101             {
2102               ses0->state = SNAT_SESSION_UDP_ACTIVE;
2103               old_port0 = udp0->src_port;
2104               udp0->src_port = new_port0;
2105               udp0->checksum = 0;
2106             }
2107
2108           switch(ses0->state)
2109             {
2110             case SNAT_SESSION_UDP_ACTIVE:
2111                 ses0->expire = now + sm->udp_timeout;
2112                 break;
2113             case SNAT_SESSION_TCP_SYN_SENT:
2114             case SNAT_SESSION_TCP_FIN_WAIT:
2115             case SNAT_SESSION_TCP_CLOSE_WAIT:
2116             case SNAT_SESSION_TCP_LAST_ACK:
2117                 ses0->expire = now + sm->tcp_transitory_timeout;
2118                 break;
2119             case SNAT_SESSION_TCP_ESTABLISHED:
2120                 ses0->expire = now + sm->tcp_established_timeout;
2121                 break;
2122             }
2123
2124         trace00:
2125           if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
2126                             && (b0->flags & VLIB_BUFFER_IS_TRACED)))
2127             {
2128               snat_in2out_trace_t *t =
2129                  vlib_add_trace (vm, node, b0, sizeof (*t));
2130               t->is_slow_path = 0;
2131               t->sw_if_index = sw_if_index0;
2132               t->next_index = next0;
2133               t->session_index = ~0;
2134               if (ses0)
2135                 t->session_index = ses0 - dm0->sessions;
2136             }
2137
2138           pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
2139
2140           /* verify speculative enqueue, maybe switch current next frame */
2141           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
2142                                            to_next, n_left_to_next,
2143                                            bi0, next0);
2144         }
2145
2146       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2147     }
2148
2149   vlib_node_increment_counter (vm, snat_det_in2out_node.index,
2150                                SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
2151                                pkts_processed);
2152   return frame->n_vectors;
2153 }
2154
2155 VLIB_REGISTER_NODE (snat_det_in2out_node) = {
2156   .function = snat_det_in2out_node_fn,
2157   .name = "snat-det-in2out",
2158   .vector_size = sizeof (u32),
2159   .format_trace = format_snat_in2out_trace,
2160   .type = VLIB_NODE_TYPE_INTERNAL,
2161
2162   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
2163   .error_strings = snat_in2out_error_strings,
2164
2165   .runtime_data_bytes = sizeof (snat_runtime_t),
2166
2167   .n_next_nodes = 3,
2168
2169   /* edit / add dispositions here */
2170   .next_nodes = {
2171     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
2172     [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
2173     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
2174   },
2175 };
2176
2177 VLIB_NODE_FUNCTION_MULTIARCH (snat_det_in2out_node, snat_det_in2out_node_fn);
2178
2179 /**
2180  * Get address and port values to be used for packet SNAT translation
2181  * and create session if needed
2182  *
2183  * @param[in,out] sm             SNAT main
2184  * @param[in,out] node           SNAT node runtime
2185  * @param[in] thread_index       thread index
2186  * @param[in,out] b0             buffer containing packet to be translated
2187  * @param[out] p_proto           protocol used for matching
2188  * @param[out] p_value           address and port after NAT translation
2189  * @param[out] p_dont_translate  if packet should not be translated
2190  * @param d                      optional parameter
2191  * @param e                      optional parameter
2192  */
2193 u32 icmp_match_in2out_det(snat_main_t *sm, vlib_node_runtime_t *node,
2194                           u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
2195                           snat_session_key_t *p_value,
2196                           u8 *p_dont_translate, void *d, void *e)
2197 {
2198   ip4_header_t *ip0;
2199   icmp46_header_t *icmp0;
2200   u32 sw_if_index0;
2201   u32 rx_fib_index0;
2202   u8 protocol;
2203   snat_det_out_key_t key0;
2204   u8 dont_translate = 0;
2205   u32 next0 = ~0;
2206   icmp_echo_header_t *echo0, *inner_echo0 = 0;
2207   ip4_header_t *inner_ip0;
2208   void *l4_header = 0;
2209   icmp46_header_t *inner_icmp0;
2210   snat_det_map_t * dm0 = 0;
2211   ip4_address_t new_addr0;
2212   u16 lo_port0, i0;
2213   snat_det_session_t * ses0 = 0;
2214   ip4_address_t in_addr;
2215   u16 in_port;
2216
2217   ip0 = vlib_buffer_get_current (b0);
2218   icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
2219   echo0 = (icmp_echo_header_t *)(icmp0+1);
2220   sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
2221   rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
2222
2223   if (!icmp_is_error_message (icmp0))
2224     {
2225       protocol = SNAT_PROTOCOL_ICMP;
2226       in_addr = ip0->src_address;
2227       in_port = echo0->identifier;
2228     }
2229   else
2230     {
2231       inner_ip0 = (ip4_header_t *)(echo0+1);
2232       l4_header = ip4_next_header (inner_ip0);
2233       protocol = ip_proto_to_snat_proto (inner_ip0->protocol);
2234       in_addr = inner_ip0->dst_address;
2235       switch (protocol)
2236         {
2237         case SNAT_PROTOCOL_ICMP:
2238           inner_icmp0 = (icmp46_header_t*)l4_header;
2239           inner_echo0 = (icmp_echo_header_t *)(inner_icmp0+1);
2240           in_port = inner_echo0->identifier;
2241           break;
2242         case SNAT_PROTOCOL_UDP:
2243         case SNAT_PROTOCOL_TCP:
2244           in_port = ((tcp_udp_header_t*)l4_header)->dst_port;
2245           break;
2246         default:
2247           b0->error = node->errors[SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL];
2248           next0 = SNAT_IN2OUT_NEXT_DROP;
2249           goto out;
2250         }
2251     }
2252
2253   dm0 = snat_det_map_by_user(sm, &in_addr);
2254   if (PREDICT_FALSE(!dm0))
2255     {
2256       clib_warning("no match for internal host %U",
2257                    format_ip4_address, &in_addr);
2258       if (PREDICT_FALSE(snat_not_translate_fast(sm, node, sw_if_index0, ip0,
2259           IP_PROTOCOL_ICMP, rx_fib_index0)))
2260         {
2261           dont_translate = 1;
2262           goto out;
2263         }
2264       next0 = SNAT_IN2OUT_NEXT_DROP;
2265       b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
2266       goto out;
2267     }
2268
2269   snat_det_forward(dm0, &in_addr, &new_addr0, &lo_port0);
2270
2271   key0.ext_host_addr = ip0->dst_address;
2272   key0.ext_host_port = 0;
2273
2274   ses0 = snat_det_find_ses_by_in(dm0, &in_addr, in_port, key0);
2275   if (PREDICT_FALSE(!ses0))
2276     {
2277       if (PREDICT_FALSE(snat_not_translate_fast(sm, node, sw_if_index0, ip0,
2278           IP_PROTOCOL_ICMP, rx_fib_index0)))
2279         {
2280           dont_translate = 1;
2281           goto out;
2282         }
2283       if (icmp0->type != ICMP4_echo_request)
2284         {
2285           b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
2286           next0 = SNAT_IN2OUT_NEXT_DROP;
2287           goto out;
2288         }
2289       for (i0 = 0; i0 < dm0->ports_per_host; i0++)
2290         {
2291           key0.out_port = clib_host_to_net_u16 (lo_port0 +
2292             ((i0 + clib_net_to_host_u16 (echo0->identifier)) % dm0->ports_per_host));
2293
2294           if (snat_det_get_ses_by_out (dm0, &in_addr, key0.as_u64))
2295             continue;
2296
2297           ses0 = snat_det_ses_create(dm0, &in_addr, echo0->identifier, &key0);
2298           break;
2299         }
2300       if (PREDICT_FALSE(!ses0))
2301         {
2302           next0 = SNAT_IN2OUT_NEXT_DROP;
2303           b0->error = node->errors[SNAT_IN2OUT_ERROR_OUT_OF_PORTS];
2304           goto out;
2305         }
2306     }
2307
2308   if (PREDICT_FALSE(icmp0->type != ICMP4_echo_request &&
2309                     !icmp_is_error_message (icmp0)))
2310     {
2311       b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
2312       next0 = SNAT_IN2OUT_NEXT_DROP;
2313       goto out;
2314     }
2315
2316   u32 now = (u32) vlib_time_now (sm->vlib_main);
2317
2318   ses0->state = SNAT_SESSION_ICMP_ACTIVE;
2319   ses0->expire = now + sm->icmp_timeout;
2320
2321 out:
2322   *p_proto = protocol;
2323   if (ses0)
2324     {
2325       p_value->addr = new_addr0;
2326       p_value->fib_index = sm->outside_fib_index;
2327       p_value->port = ses0->out.out_port;
2328     }
2329   *p_dont_translate = dont_translate;
2330   if (d)
2331     *(snat_det_session_t**)d = ses0;
2332   if (e)
2333     *(snat_det_map_t**)e = dm0;
2334   return next0;
2335 }
2336
2337 /**********************/
2338 /*** worker handoff ***/
2339 /**********************/
2340 static uword
2341 snat_in2out_worker_handoff_fn (vlib_main_t * vm,
2342                                vlib_node_runtime_t * node,
2343                                vlib_frame_t * frame)
2344 {
2345   snat_main_t *sm = &snat_main;
2346   vlib_thread_main_t *tm = vlib_get_thread_main ();
2347   u32 n_left_from, *from, *to_next = 0;
2348   static __thread vlib_frame_queue_elt_t **handoff_queue_elt_by_worker_index;
2349   static __thread vlib_frame_queue_t **congested_handoff_queue_by_worker_index
2350     = 0;
2351   vlib_frame_queue_elt_t *hf = 0;
2352   vlib_frame_t *f = 0;
2353   int i;
2354   u32 n_left_to_next_worker = 0, *to_next_worker = 0;
2355   u32 next_worker_index = 0;
2356   u32 current_worker_index = ~0;
2357   u32 thread_index = vlib_get_thread_index ();
2358
2359   ASSERT (vec_len (sm->workers));
2360
2361   if (PREDICT_FALSE (handoff_queue_elt_by_worker_index == 0))
2362     {
2363       vec_validate (handoff_queue_elt_by_worker_index, tm->n_vlib_mains - 1);
2364
2365       vec_validate_init_empty (congested_handoff_queue_by_worker_index,
2366                                sm->first_worker_index + sm->num_workers - 1,
2367                                (vlib_frame_queue_t *) (~0));
2368     }
2369
2370   from = vlib_frame_vector_args (frame);
2371   n_left_from = frame->n_vectors;
2372
2373   while (n_left_from > 0)
2374     {
2375       u32 bi0;
2376       vlib_buffer_t *b0;
2377       u32 sw_if_index0;
2378       u32 rx_fib_index0;
2379       ip4_header_t * ip0;
2380       u8 do_handoff;
2381
2382       bi0 = from[0];
2383       from += 1;
2384       n_left_from -= 1;
2385
2386       b0 = vlib_get_buffer (vm, bi0);
2387
2388       sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2389       rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index(sw_if_index0);
2390
2391       ip0 = vlib_buffer_get_current (b0);
2392
2393       next_worker_index = sm->worker_in2out_cb(ip0, rx_fib_index0);
2394
2395       if (PREDICT_FALSE (next_worker_index != thread_index))
2396         {
2397           do_handoff = 1;
2398
2399           if (next_worker_index != current_worker_index)
2400             {
2401               if (hf)
2402                 hf->n_vectors = VLIB_FRAME_SIZE - n_left_to_next_worker;
2403
2404               hf = vlib_get_worker_handoff_queue_elt (sm->fq_in2out_index,
2405                                                       next_worker_index,
2406                                                       handoff_queue_elt_by_worker_index);
2407
2408               n_left_to_next_worker = VLIB_FRAME_SIZE - hf->n_vectors;
2409               to_next_worker = &hf->buffer_index[hf->n_vectors];
2410               current_worker_index = next_worker_index;
2411             }
2412
2413           /* enqueue to correct worker thread */
2414           to_next_worker[0] = bi0;
2415           to_next_worker++;
2416           n_left_to_next_worker--;
2417
2418           if (n_left_to_next_worker == 0)
2419             {
2420               hf->n_vectors = VLIB_FRAME_SIZE;
2421               vlib_put_frame_queue_elt (hf);
2422               current_worker_index = ~0;
2423               handoff_queue_elt_by_worker_index[next_worker_index] = 0;
2424               hf = 0;
2425             }
2426         }
2427       else
2428         {
2429           do_handoff = 0;
2430           /* if this is 1st frame */
2431           if (!f)
2432             {
2433               f = vlib_get_frame_to_node (vm, sm->in2out_node_index);
2434               to_next = vlib_frame_vector_args (f);
2435             }
2436
2437           to_next[0] = bi0;
2438           to_next += 1;
2439           f->n_vectors++;
2440         }
2441
2442       if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
2443                          && (b0->flags & VLIB_BUFFER_IS_TRACED)))
2444         {
2445           snat_in2out_worker_handoff_trace_t *t =
2446             vlib_add_trace (vm, node, b0, sizeof (*t));
2447           t->next_worker_index = next_worker_index;
2448           t->do_handoff = do_handoff;
2449         }
2450     }
2451
2452   if (f)
2453     vlib_put_frame_to_node (vm, sm->in2out_node_index, f);
2454
2455   if (hf)
2456     hf->n_vectors = VLIB_FRAME_SIZE - n_left_to_next_worker;
2457
2458   /* Ship frames to the worker nodes */
2459   for (i = 0; i < vec_len (handoff_queue_elt_by_worker_index); i++)
2460     {
2461       if (handoff_queue_elt_by_worker_index[i])
2462         {
2463           hf = handoff_queue_elt_by_worker_index[i];
2464           /*
2465            * It works better to let the handoff node
2466            * rate-adapt, always ship the handoff queue element.
2467            */
2468           if (1 || hf->n_vectors == hf->last_n_vectors)
2469             {
2470               vlib_put_frame_queue_elt (hf);
2471               handoff_queue_elt_by_worker_index[i] = 0;
2472             }
2473           else
2474             hf->last_n_vectors = hf->n_vectors;
2475         }
2476       congested_handoff_queue_by_worker_index[i] =
2477         (vlib_frame_queue_t *) (~0);
2478     }
2479   hf = 0;
2480   current_worker_index = ~0;
2481   return frame->n_vectors;
2482 }
2483
2484 VLIB_REGISTER_NODE (snat_in2out_worker_handoff_node) = {
2485   .function = snat_in2out_worker_handoff_fn,
2486   .name = "snat-in2out-worker-handoff",
2487   .vector_size = sizeof (u32),
2488   .format_trace = format_snat_in2out_worker_handoff_trace,
2489   .type = VLIB_NODE_TYPE_INTERNAL,
2490
2491   .n_next_nodes = 1,
2492
2493   .next_nodes = {
2494     [0] = "error-drop",
2495   },
2496 };
2497
2498 VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_worker_handoff_node, snat_in2out_worker_handoff_fn);
2499
2500 static uword
2501 snat_in2out_fast_static_map_fn (vlib_main_t * vm,
2502                                 vlib_node_runtime_t * node,
2503                                 vlib_frame_t * frame)
2504 {
2505   u32 n_left_from, * from, * to_next;
2506   snat_in2out_next_t next_index;
2507   u32 pkts_processed = 0;
2508   snat_main_t * sm = &snat_main;
2509   u32 stats_node_index;
2510
2511   stats_node_index = snat_in2out_fast_node.index;
2512
2513   from = vlib_frame_vector_args (frame);
2514   n_left_from = frame->n_vectors;
2515   next_index = node->cached_next_index;
2516
2517   while (n_left_from > 0)
2518     {
2519       u32 n_left_to_next;
2520
2521       vlib_get_next_frame (vm, node, next_index,
2522                            to_next, n_left_to_next);
2523
2524       while (n_left_from > 0 && n_left_to_next > 0)
2525         {
2526           u32 bi0;
2527           vlib_buffer_t * b0;
2528           u32 next0;
2529           u32 sw_if_index0;
2530           ip4_header_t * ip0;
2531           ip_csum_t sum0;
2532           u32 new_addr0, old_addr0;
2533           u16 old_port0, new_port0;
2534           udp_header_t * udp0;
2535           tcp_header_t * tcp0;
2536           icmp46_header_t * icmp0;
2537           snat_session_key_t key0, sm0;
2538           u32 proto0;
2539           u32 rx_fib_index0;
2540
2541           /* speculatively enqueue b0 to the current next frame */
2542           bi0 = from[0];
2543           to_next[0] = bi0;
2544           from += 1;
2545           to_next += 1;
2546           n_left_from -= 1;
2547           n_left_to_next -= 1;
2548
2549           b0 = vlib_get_buffer (vm, bi0);
2550           next0 = SNAT_IN2OUT_NEXT_LOOKUP;
2551
2552           ip0 = vlib_buffer_get_current (b0);
2553           udp0 = ip4_next_header (ip0);
2554           tcp0 = (tcp_header_t *) udp0;
2555           icmp0 = (icmp46_header_t *) udp0;
2556
2557           sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
2558           rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index(sw_if_index0);
2559
2560           if (PREDICT_FALSE(ip0->ttl == 1))
2561             {
2562               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
2563               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
2564                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
2565                                            0);
2566               next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
2567               goto trace0;
2568             }
2569
2570           proto0 = ip_proto_to_snat_proto (ip0->protocol);
2571
2572           if (PREDICT_FALSE (proto0 == ~0))
2573               goto trace0;
2574
2575           if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
2576             {
2577               next0 = icmp_in2out(sm, b0, ip0, icmp0, sw_if_index0,
2578                                   rx_fib_index0, node, next0, ~0, 0, 0);
2579               goto trace0;
2580             }
2581
2582           key0.addr = ip0->src_address;
2583           key0.port = udp0->src_port;
2584           key0.fib_index = rx_fib_index0;
2585
2586           if (snat_static_mapping_match(sm, key0, &sm0, 0, 0))
2587             {
2588               b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
2589               next0= SNAT_IN2OUT_NEXT_DROP;
2590               goto trace0;
2591             }
2592
2593           new_addr0 = sm0.addr.as_u32;
2594           new_port0 = sm0.port;
2595           vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
2596           old_addr0 = ip0->src_address.as_u32;
2597           ip0->src_address.as_u32 = new_addr0;
2598
2599           sum0 = ip0->checksum;
2600           sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
2601                                  ip4_header_t,
2602                                  src_address /* changed member */);
2603           ip0->checksum = ip_csum_fold (sum0);
2604
2605           if (PREDICT_FALSE(new_port0 != udp0->dst_port))
2606             {
2607               if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
2608                 {
2609                   old_port0 = tcp0->src_port;
2610                   tcp0->src_port = new_port0;
2611
2612                   sum0 = tcp0->checksum;
2613                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
2614                                          ip4_header_t,
2615                                          dst_address /* changed member */);
2616                   sum0 = ip_csum_update (sum0, old_port0, new_port0,
2617                                          ip4_header_t /* cheat */,
2618                                          length /* changed member */);
2619                   tcp0->checksum = ip_csum_fold(sum0);
2620                 }
2621               else
2622                 {
2623                   old_port0 = udp0->src_port;
2624                   udp0->src_port = new_port0;
2625                   udp0->checksum = 0;
2626                 }
2627             }
2628           else
2629             {
2630               if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
2631                 {
2632                   sum0 = tcp0->checksum;
2633                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
2634                                          ip4_header_t,
2635                                          dst_address /* changed member */);
2636                   tcp0->checksum = ip_csum_fold(sum0);
2637                 }
2638             }
2639
2640           /* Hairpinning */
2641           snat_hairpinning (sm, b0, ip0, udp0, tcp0, proto0);
2642
2643         trace0:
2644           if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
2645                             && (b0->flags & VLIB_BUFFER_IS_TRACED)))
2646             {
2647               snat_in2out_trace_t *t =
2648                  vlib_add_trace (vm, node, b0, sizeof (*t));
2649               t->sw_if_index = sw_if_index0;
2650               t->next_index = next0;
2651             }
2652
2653           pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
2654
2655           /* verify speculative enqueue, maybe switch current next frame */
2656           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
2657                                            to_next, n_left_to_next,
2658                                            bi0, next0);
2659         }
2660
2661       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2662     }
2663
2664   vlib_node_increment_counter (vm, stats_node_index,
2665                                SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
2666                                pkts_processed);
2667   return frame->n_vectors;
2668 }
2669
2670
2671 VLIB_REGISTER_NODE (snat_in2out_fast_node) = {
2672   .function = snat_in2out_fast_static_map_fn,
2673   .name = "snat-in2out-fast",
2674   .vector_size = sizeof (u32),
2675   .format_trace = format_snat_in2out_fast_trace,
2676   .type = VLIB_NODE_TYPE_INTERNAL,
2677
2678   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
2679   .error_strings = snat_in2out_error_strings,
2680
2681   .runtime_data_bytes = sizeof (snat_runtime_t),
2682
2683   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
2684
2685   /* edit / add dispositions here */
2686   .next_nodes = {
2687     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
2688     [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
2689     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "snat-in2out-slowpath",
2690     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
2691   },
2692 };
2693
2694 VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_fast_node, snat_in2out_fast_static_map_fn);