src/plugins/nat/in2out.c

   1 /*
   2  * Copyright (c) 2016 Cisco and/or its affiliates.
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15 /**
  16  * @file
  17  * @brief NAT44 inside to outside network translation
  18  */
  19
  20 #include <vlib/vlib.h>
  21 #include <vnet/vnet.h>
  22 #include <vnet/pg/pg.h>
  23
  24 #include <vnet/ip/ip.h>
  25 #include <vnet/ethernet/ethernet.h>
  26 #include <vnet/fib/ip4_fib.h>
  27 #include <vnet/udp/udp.h>
  28 #include <nat/nat.h>
  29 #include <nat/nat_ipfix_logging.h>
  30 #include <nat/nat_inlines.h>
  31 #include <nat/nat44/inlines.h>
  32 #include <nat/nat_syslog.h>
  33 #include <nat/nat_ha.h>
  34
  35 #include <vppinfra/hash.h>
  36 #include <vppinfra/error.h>
  37 #include <vppinfra/elog.h>
  38 #include <nat/lib/nat_inlines.h>
  39
  40 typedef struct
  41 {
  42   u32 sw_if_index;
  43   u32 next_index;
  44   u32 session_index;
  45   u32 is_slow_path;
  46   u32 is_hairpinning;
  47 } snat_in2out_trace_t;
  48
  49 /* packet trace format function */
  50 static u8 *
  51 format_snat_in2out_trace (u8 * s, va_list * args)
  52 {
  53   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  54   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  55   snat_in2out_trace_t *t = va_arg (*args, snat_in2out_trace_t *);
  56   char *tag;
  57
  58   tag = t->is_slow_path ? "NAT44_IN2OUT_SLOW_PATH" : "NAT44_IN2OUT_FAST_PATH";
  59
  60   s = format (s, "%s: sw_if_index %d, next index %d, session %d", tag,
  61               t->sw_if_index, t->next_index, t->session_index);
  62   if (t->is_hairpinning)
  63     {
  64       s = format (s, ", with-hairpinning");
  65     }
  66
  67   return s;
  68 }
  69
  70 static u8 *
  71 format_snat_in2out_fast_trace (u8 * s, va_list * args)
  72 {
  73   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  74   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  75   snat_in2out_trace_t *t = va_arg (*args, snat_in2out_trace_t *);
  76
  77   s = format (s, "NAT44_IN2OUT_FAST: sw_if_index %d, next index %d",
  78               t->sw_if_index, t->next_index);
  79
  80   return s;
  81 }
  82
  83 #define foreach_snat_in2out_error                       \
  84 _(UNSUPPORTED_PROTOCOL, "unsupported protocol")         \
  85 _(IN2OUT_PACKETS, "good in2out packets processed")      \
  86 _(OUT_OF_PORTS, "out of ports")                         \
  87 _(BAD_OUTSIDE_FIB, "outside VRF ID not found")          \
  88 _(BAD_ICMP_TYPE, "unsupported ICMP type")               \
  89 _(NO_TRANSLATION, "no translation")                     \
  90 _(MAX_SESSIONS_EXCEEDED, "maximum sessions exceeded")   \
  91 _(DROP_FRAGMENT, "drop fragment")                       \
  92 _(TCP_PACKETS, "TCP packets")                           \
  93 _(UDP_PACKETS, "UDP packets")                           \
  94 _(ICMP_PACKETS, "ICMP packets")                         \
  95 _(OTHER_PACKETS, "other protocol packets")              \
  96 _(FRAGMENTS, "fragments")                               \
  97 _(CACHED_FRAGMENTS, "cached fragments")                 \
  98 _(PROCESSED_FRAGMENTS, "processed fragments")
  99
 100 typedef enum
 101 {
 102 #define _(sym,str) SNAT_IN2OUT_ERROR_##sym,
 103   foreach_snat_in2out_error
 104 #undef _
 105     SNAT_IN2OUT_N_ERROR,
 106 } snat_in2out_error_t;
 107
 108 static char *snat_in2out_error_strings[] = {
 109 #define _(sym,string) string,
 110   foreach_snat_in2out_error
 111 #undef _
 112 };
 113
 114 typedef enum
 115 {
 116   SNAT_IN2OUT_NEXT_LOOKUP,
 117   SNAT_IN2OUT_NEXT_DROP,
 118   SNAT_IN2OUT_NEXT_ICMP_ERROR,
 119   SNAT_IN2OUT_NEXT_SLOW_PATH,
 120   SNAT_IN2OUT_N_NEXT,
 121 } snat_in2out_next_t;
 122
 123 static inline int
 124 snat_not_translate (snat_main_t * sm, vlib_node_runtime_t * node,
 125                     u32 sw_if_index0, ip4_header_t * ip0, u32 proto0,
 126                     u32 rx_fib_index0, u32 thread_index)
 127 {
 128   udp_header_t *udp0 = ip4_next_header (ip0);
 129   clib_bihash_kv_8_8_t kv0, value0;
 130
 131   init_nat_k (&kv0, ip0->dst_address, udp0->dst_port, sm->outside_fib_index,
 132               proto0);
 133
 134   /* NAT packet aimed at external address if */
 135   /* has active sessions */
 136   if (clib_bihash_search_8_8 (&sm->per_thread_data[thread_index].out2in, &kv0,
 137                               &value0))
 138     {
 139       /* or is static mappings */
 140       ip4_address_t dummy_addr;
 141       u16 dummy_port;
 142       u32 dummy_fib_index;
 143       if (!snat_static_mapping_match
 144           (sm, ip0->dst_address, udp0->dst_port, sm->outside_fib_index,
 145            proto0, &dummy_addr, &dummy_port, &dummy_fib_index, 1, 0, 0, 0, 0,
 146            0))
 147         return 0;
 148     }
 149   else
 150     return 0;
 151
 152   if (sm->forwarding_enabled)
 153     return 1;
 154
 155   return snat_not_translate_fast (sm, node, sw_if_index0, ip0, proto0,
 156                                   rx_fib_index0);
 157 }
 158
 159 static inline int
 160 nat_not_translate_output_feature (snat_main_t * sm, ip4_header_t * ip0,
 161                                   u32 proto0, u16 src_port, u16 dst_port,
 162                                   u32 thread_index, u32 sw_if_index)
 163 {
 164   clib_bihash_kv_8_8_t kv0, value0;
 165   snat_interface_t *i;
 166
 167   /* src NAT check */
 168   init_nat_k (&kv0, ip0->src_address, src_port,
 169               ip4_fib_table_get_index_for_sw_if_index (sw_if_index), proto0);
 170
 171   if (!clib_bihash_search_8_8
 172       (&sm->per_thread_data[thread_index].out2in, &kv0, &value0))
 173     return 1;
 174
 175   /* dst NAT check */
 176   init_nat_k (&kv0, ip0->dst_address, dst_port,
 177               ip4_fib_table_get_index_for_sw_if_index (sw_if_index), proto0);
 178   if (!clib_bihash_search_8_8
 179       (&sm->per_thread_data[thread_index].in2out, &kv0, &value0))
 180     {
 181       /* hairpinning */
 182     /* *INDENT-OFF* */
 183     pool_foreach (i, sm->output_feature_interfaces,
 184     ({
 185       if ((nat_interface_is_inside(i)) && (sw_if_index == i->sw_if_index))
 186         return 0;
 187     }));
 188     /* *INDENT-ON* */
 189       return 1;
 190     }
 191
 192   return 0;
 193 }
 194
 195 #ifndef CLIB_MARCH_VARIANT
 196 int
 197 nat44_i2o_is_idle_session_cb (clib_bihash_kv_8_8_t * kv, void *arg)
 198 {
 199   snat_main_t *sm = &snat_main;
 200   nat44_is_idle_session_ctx_t *ctx = arg;
 201   snat_session_t *s;
 202   u64 sess_timeout_time;
 203   snat_main_per_thread_data_t *tsm = vec_elt_at_index (sm->per_thread_data,
 204                                                        ctx->thread_index);
 205   clib_bihash_kv_8_8_t s_kv;
 206
 207   s = pool_elt_at_index (tsm->sessions, kv->value);
 208   sess_timeout_time = s->last_heard + (f64) nat44_session_get_timeout (sm, s);
 209   if (ctx->now >= sess_timeout_time)
 210     {
 211       init_nat_o2i_k (&s_kv, s);
 212       if (clib_bihash_add_del_8_8 (&tsm->out2in, &s_kv, 0))
 213         nat_elog_warn ("out2in key del failed");
 214
 215       snat_ipfix_logging_nat44_ses_delete (ctx->thread_index,
 216                                            s->in2out.addr.as_u32,
 217                                            s->out2in.addr.as_u32,
 218                                            s->nat_proto,
 219                                            s->in2out.port,
 220                                            s->out2in.port,
 221                                            s->in2out.fib_index);
 222
 223       nat_syslog_nat44_apmdel (s->user_index, s->in2out.fib_index,
 224                                &s->in2out.addr, s->in2out.port,
 225                                &s->out2in.addr, s->out2in.port, s->nat_proto);
 226
 227       nat_ha_sdel (&s->out2in.addr, s->out2in.port, &s->ext_host_addr,
 228                    s->ext_host_port, s->nat_proto, s->out2in.fib_index,
 229                    ctx->thread_index);
 230
 231       if (!snat_is_session_static (s))
 232         snat_free_outside_address_and_port (sm->addresses, ctx->thread_index,
 233                                             &s->out2in.addr,
 234                                             s->out2in.port, s->nat_proto);
 235
 236       nat44_delete_session (sm, s, ctx->thread_index);
 237       return 1;
 238     }
 239
 240   return 0;
 241 }
 242 #endif
 243
 244 static u32
 245 slow_path (snat_main_t * sm, vlib_buffer_t * b0,
 246            ip4_header_t * ip0,
 247            ip4_address_t i2o_addr,
 248            u16 i2o_port,
 249            u32 rx_fib_index0,
 250            nat_protocol_t nat_proto,
 251            snat_session_t ** sessionp,
 252            vlib_node_runtime_t * node, u32 next0, u32 thread_index, f64 now)
 253 {
 254   snat_user_t *u;
 255   snat_session_t *s = 0;
 256   clib_bihash_kv_8_8_t kv0;
 257   u8 is_sm = 0;
 258   nat_outside_fib_t *outside_fib;
 259   fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
 260   u8 identity_nat;
 261   fib_prefix_t pfx = {
 262     .fp_proto = FIB_PROTOCOL_IP4,
 263     .fp_len = 32,
 264     .fp_addr = {
 265                 .ip4.as_u32 = ip0->dst_address.as_u32,
 266                 },
 267   };
 268   nat44_is_idle_session_ctx_t ctx0;
 269   ip4_address_t sm_addr;
 270   u16 sm_port;
 271   u32 sm_fib_index;
 272
 273   if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
 274     {
 275       b0->error = node->errors[SNAT_IN2OUT_ERROR_MAX_SESSIONS_EXCEEDED];
 276       nat_ipfix_logging_max_sessions (thread_index,
 277                                       sm->max_translations_per_thread);
 278       nat_elog_notice ("maximum sessions exceeded");
 279       return SNAT_IN2OUT_NEXT_DROP;
 280     }
 281
 282   /* First try to match static mapping by local address and port */
 283   if (snat_static_mapping_match
 284       (sm, i2o_addr, i2o_port, rx_fib_index0, nat_proto, &sm_addr,
 285        &sm_port, &sm_fib_index, 0, 0, 0, 0, 0, &identity_nat))
 286     {
 287       /* Try to create dynamic translation */
 288       if (snat_alloc_outside_address_and_port (sm->addresses, rx_fib_index0,
 289                                                thread_index,
 290                                                nat_proto,
 291                                                &sm_addr, &sm_port,
 292                                                sm->port_per_thread,
 293                                                sm->per_thread_data
 294                                                [thread_index].snat_thread_index))
 295         {
 296           b0->error = node->errors[SNAT_IN2OUT_ERROR_OUT_OF_PORTS];
 297           return SNAT_IN2OUT_NEXT_DROP;
 298         }
 299     }
 300   else
 301     {
 302       if (PREDICT_FALSE (identity_nat))
 303         {
 304           *sessionp = s;
 305           return next0;
 306         }
 307
 308       is_sm = 1;
 309     }
 310
 311   u = nat_user_get_or_create (sm, &ip0->src_address, rx_fib_index0,
 312                               thread_index);
 313   if (!u)
 314     {
 315       nat_elog_warn ("create NAT user failed");
 316       return SNAT_IN2OUT_NEXT_DROP;
 317     }
 318
 319   s = nat_session_alloc_or_recycle (sm, u, thread_index, now);
 320   if (!s)
 321     {
 322       nat44_delete_user_with_no_session (sm, u, thread_index);
 323       nat_elog_warn ("create NAT session failed");
 324       return SNAT_IN2OUT_NEXT_DROP;
 325     }
 326
 327   if (is_sm)
 328     s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 329   user_session_increment (sm, u, is_sm);
 330   s->in2out.addr = i2o_addr;
 331   s->in2out.port = i2o_port;
 332   s->in2out.fib_index = rx_fib_index0;
 333   s->nat_proto = nat_proto;
 334   s->out2in.addr = sm_addr;
 335   s->out2in.port = sm_port;
 336   s->out2in.fib_index = sm->outside_fib_index;
 337   switch (vec_len (sm->outside_fibs))
 338     {
 339     case 0:
 340       s->out2in.fib_index = sm->outside_fib_index;
 341       break;
 342     case 1:
 343       s->out2in.fib_index = sm->outside_fibs[0].fib_index;
 344       break;
 345     default:
 346       /* *INDENT-OFF* */
 347       vec_foreach (outside_fib, sm->outside_fibs)
 348         {
 349           fei = fib_table_lookup (outside_fib->fib_index, &pfx);
 350           if (FIB_NODE_INDEX_INVALID != fei)
 351             {
 352               if (fib_entry_get_resolving_interface (fei) != ~0)
 353                 {
 354                   s->out2in.fib_index = outside_fib->fib_index;
 355                   break;
 356                 }
 357             }
 358         }
 359       /* *INDENT-ON* */
 360       break;
 361     }
 362   s->ext_host_addr.as_u32 = ip0->dst_address.as_u32;
 363   s->ext_host_port = vnet_buffer (b0)->ip.reass.l4_dst_port;
 364   *sessionp = s;
 365
 366   /* Add to translation hashes */
 367   ctx0.now = now;
 368   ctx0.thread_index = thread_index;
 369   init_nat_i2o_kv (&kv0, s, s - sm->per_thread_data[thread_index].sessions);
 370   if (clib_bihash_add_or_overwrite_stale_8_8
 371       (&sm->per_thread_data[thread_index].in2out, &kv0,
 372        nat44_i2o_is_idle_session_cb, &ctx0))
 373     nat_elog_notice ("in2out key add failed");
 374
 375   init_nat_o2i_kv (&kv0, s, s - sm->per_thread_data[thread_index].sessions);
 376   if (clib_bihash_add_or_overwrite_stale_8_8
 377       (&sm->per_thread_data[thread_index].out2in, &kv0,
 378        nat44_o2i_is_idle_session_cb, &ctx0))
 379     nat_elog_notice ("out2in key add failed");
 380
 381   /* log NAT event */
 382   snat_ipfix_logging_nat44_ses_create (thread_index,
 383                                        s->in2out.addr.as_u32,
 384                                        s->out2in.addr.as_u32,
 385                                        s->nat_proto,
 386                                        s->in2out.port,
 387                                        s->out2in.port, s->in2out.fib_index);
 388
 389   nat_syslog_nat44_apmadd (s->user_index, s->in2out.fib_index,
 390                            &s->in2out.addr, s->in2out.port, &s->out2in.addr,
 391                            s->out2in.port, s->nat_proto);
 392
 393   nat_ha_sadd (&s->in2out.addr, s->in2out.port, &s->out2in.addr,
 394                s->out2in.port, &s->ext_host_addr, s->ext_host_port,
 395                &s->ext_host_nat_addr, s->ext_host_nat_port,
 396                s->nat_proto, s->in2out.fib_index, s->flags, thread_index, 0);
 397
 398   return next0;
 399 }
 400
 401 #ifndef CLIB_MARCH_VARIANT
 402 static_always_inline snat_in2out_error_t
 403 icmp_get_key (vlib_buffer_t * b, ip4_header_t * ip0,
 404               ip4_address_t * addr, u16 * port, nat_protocol_t * nat_proto)
 405 {
 406   icmp46_header_t *icmp0;
 407   icmp_echo_header_t *echo0, *inner_echo0 = 0;
 408   ip4_header_t *inner_ip0 = 0;
 409   void *l4_header = 0;
 410   icmp46_header_t *inner_icmp0;
 411
 412   icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
 413   echo0 = (icmp_echo_header_t *) (icmp0 + 1);
 414
 415   if (!icmp_type_is_error_message
 416       (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags))
 417     {
 418       *nat_proto = NAT_PROTOCOL_ICMP;
 419       *addr = ip0->src_address;
 420       *port = vnet_buffer (b)->ip.reass.l4_src_port;
 421     }
 422   else
 423     {
 424       inner_ip0 = (ip4_header_t *) (echo0 + 1);
 425       l4_header = ip4_next_header (inner_ip0);
 426       *nat_proto = ip_proto_to_nat_proto (inner_ip0->protocol);
 427       *addr = inner_ip0->dst_address;
 428       switch (*nat_proto)
 429         {
 430         case NAT_PROTOCOL_ICMP:
 431           inner_icmp0 = (icmp46_header_t *) l4_header;
 432           inner_echo0 = (icmp_echo_header_t *) (inner_icmp0 + 1);
 433           *port = inner_echo0->identifier;
 434           break;
 435         case NAT_PROTOCOL_UDP:
 436         case NAT_PROTOCOL_TCP:
 437           *port = ((tcp_udp_header_t *) l4_header)->dst_port;
 438           break;
 439         default:
 440           return SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL;
 441         }
 442     }
 443   return -1;                    /* success */
 444 }
 445
 446 /**
 447  * Get address and port values to be used for ICMP packet translation
 448  * and create session if needed
 449  *
 450  * @param[in,out] sm             NAT main
 451  * @param[in,out] node           NAT node runtime
 452  * @param[in] thread_index       thread index
 453  * @param[in,out] b0             buffer containing packet to be translated
 454  * @param[in,out] ip0            ip header
 455  * @param[out] p_proto           protocol used for matching
 456  * @param[out] p_value           address and port after NAT translation
 457  * @param[out] p_dont_translate  if packet should not be translated
 458  * @param d                      optional parameter
 459  * @param e                      optional parameter
 460  */
 461 u32
 462 icmp_match_in2out_slow (snat_main_t * sm, vlib_node_runtime_t * node,
 463                         u32 thread_index, vlib_buffer_t * b0,
 464                         ip4_header_t * ip0, ip4_address_t * addr, u16 * port,
 465                         u32 * fib_index, nat_protocol_t * proto, void *d,
 466                         void *e, u8 * dont_translate)
 467 {
 468   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 469   u32 sw_if_index0;
 470   snat_session_t *s0 = 0;
 471   clib_bihash_kv_8_8_t kv0, value0;
 472   u32 next0 = ~0;
 473   int err;
 474   vlib_main_t *vm = vlib_get_main ();
 475   *dont_translate = 0;
 476
 477   sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 478   *fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
 479
 480   err = icmp_get_key (b0, ip0, addr, port, proto);
 481   if (err != -1)
 482     {
 483       b0->error = node->errors[err];
 484       next0 = SNAT_IN2OUT_NEXT_DROP;
 485       goto out;
 486     }
 487
 488   init_nat_k (&kv0, *addr, *port, *fib_index, *proto);
 489   if (clib_bihash_search_8_8 (&tsm->in2out, &kv0, &value0))
 490     {
 491       if (vnet_buffer (b0)->sw_if_index[VLIB_TX] != ~0)
 492         {
 493           if (PREDICT_FALSE
 494               (nat_not_translate_output_feature
 495                (sm, ip0, *proto, *port, *port, thread_index, sw_if_index0)))
 496             {
 497               *dont_translate = 1;
 498               goto out;
 499             }
 500         }
 501       else
 502         {
 503           if (PREDICT_FALSE (snat_not_translate (sm, node, sw_if_index0,
 504                                                  ip0, NAT_PROTOCOL_ICMP,
 505                                                  *fib_index, thread_index)))
 506             {
 507               *dont_translate = 1;
 508               goto out;
 509             }
 510         }
 511
 512       if (PREDICT_FALSE
 513           (icmp_type_is_error_message
 514            (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags)))
 515         {
 516           b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
 517           next0 = SNAT_IN2OUT_NEXT_DROP;
 518           goto out;
 519         }
 520
 521       next0 =
 522         slow_path (sm, b0, ip0, *addr, *port, *fib_index, *proto, &s0, node,
 523                    next0, thread_index, vlib_time_now (vm));
 524
 525       if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
 526         goto out;
 527
 528       if (!s0)
 529         {
 530           *dont_translate = 1;
 531           goto out;
 532         }
 533     }
 534   else
 535     {
 536       if (PREDICT_FALSE
 537           (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
 538            ICMP4_echo_request
 539            && vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
 540            ICMP4_echo_reply
 541            && !icmp_type_is_error_message (vnet_buffer (b0)->ip.
 542                                            reass.icmp_type_or_tcp_flags)))
 543         {
 544           b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
 545           next0 = SNAT_IN2OUT_NEXT_DROP;
 546           goto out;
 547         }
 548
 549       s0 = pool_elt_at_index (tsm->sessions, value0.value);
 550     }
 551
 552 out:
 553   if (s0)
 554     {
 555       *addr = s0->out2in.addr;
 556       *port = s0->out2in.port;
 557       *fib_index = s0->out2in.fib_index;
 558     }
 559   if (d)
 560     *(snat_session_t **) (d) = s0;
 561   return next0;
 562 }
 563 #endif
 564
 565 #ifndef CLIB_MARCH_VARIANT
 566 /**
 567  * Get address and port values to be used for ICMP packet translation
 568  *
 569  * @param[in] sm                 NAT main
 570  * @param[in,out] node           NAT node runtime
 571  * @param[in] thread_index       thread index
 572  * @param[in,out] b0             buffer containing packet to be translated
 573  * @param[in,out] ip0            ip header
 574  * @param[out] p_proto           protocol used for matching
 575  * @param[out] p_value           address and port after NAT translation
 576  * @param[out] p_dont_translate  if packet should not be translated
 577  * @param d                      optional parameter
 578  * @param e                      optional parameter
 579  */
 580 u32
 581 icmp_match_in2out_fast (snat_main_t * sm, vlib_node_runtime_t * node,
 582                         u32 thread_index, vlib_buffer_t * b0,
 583                         ip4_header_t * ip0, ip4_address_t * addr, u16 * port,
 584                         u32 * fib_index, nat_protocol_t * proto, void *d,
 585                         void *e, u8 * dont_translate)
 586 {
 587   u32 sw_if_index0;
 588   u8 is_addr_only;
 589   u32 next0 = ~0;
 590   int err;
 591   *dont_translate = 0;
 592
 593   sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 594   *fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
 595
 596   err = icmp_get_key (b0, ip0, addr, port, proto);
 597   if (err != -1)
 598     {
 599       b0->error = node->errors[err];
 600       next0 = SNAT_IN2OUT_NEXT_DROP;
 601       goto out;
 602     }
 603
 604   ip4_address_t sm_addr;
 605   u16 sm_port;
 606   u32 sm_fib_index;
 607
 608   if (snat_static_mapping_match
 609       (sm, *addr, *port, *fib_index, *proto, &sm_addr, &sm_port,
 610        &sm_fib_index, 0, &is_addr_only, 0, 0, 0, 0))
 611     {
 612       if (PREDICT_FALSE (snat_not_translate_fast (sm, node, sw_if_index0, ip0,
 613                                                   IP_PROTOCOL_ICMP,
 614                                                   *fib_index)))
 615         {
 616           *dont_translate = 1;
 617           goto out;
 618         }
 619
 620       if (icmp_type_is_error_message
 621           (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags))
 622         {
 623           next0 = SNAT_IN2OUT_NEXT_DROP;
 624           goto out;
 625         }
 626
 627       b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
 628       next0 = SNAT_IN2OUT_NEXT_DROP;
 629       goto out;
 630     }
 631
 632   if (PREDICT_FALSE
 633       (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags != ICMP4_echo_request
 634        && (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
 635            ICMP4_echo_reply || !is_addr_only)
 636        && !icmp_type_is_error_message (vnet_buffer (b0)->ip.
 637                                        reass.icmp_type_or_tcp_flags)))
 638     {
 639       b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
 640       next0 = SNAT_IN2OUT_NEXT_DROP;
 641       goto out;
 642     }
 643
 644 out:
 645   return next0;
 646 }
 647 #endif
 648
 649 #ifndef CLIB_MARCH_VARIANT
 650 u32
 651 icmp_in2out (snat_main_t * sm,
 652              vlib_buffer_t * b0,
 653              ip4_header_t * ip0,
 654              icmp46_header_t * icmp0,
 655              u32 sw_if_index0,
 656              u32 rx_fib_index0,
 657              vlib_node_runtime_t * node,
 658              u32 next0, u32 thread_index, void *d, void *e)
 659 {
 660   vlib_main_t *vm = vlib_get_main ();
 661   ip4_address_t addr;
 662   u16 port;
 663   u32 fib_index;
 664   nat_protocol_t protocol;
 665   icmp_echo_header_t *echo0, *inner_echo0 = 0;
 666   ip4_header_t *inner_ip0;
 667   void *l4_header = 0;
 668   icmp46_header_t *inner_icmp0;
 669   u8 dont_translate;
 670   u32 new_addr0, old_addr0;
 671   u16 old_id0, new_id0;
 672   u16 old_checksum0, new_checksum0;
 673   ip_csum_t sum0;
 674   u16 checksum0;
 675   u32 next0_tmp;
 676
 677   echo0 = (icmp_echo_header_t *) (icmp0 + 1);
 678
 679   next0_tmp =
 680     sm->icmp_match_in2out_cb (sm, node, thread_index, b0, ip0, &addr, &port,
 681                               &fib_index, &protocol, d, e, &dont_translate);
 682   if (next0_tmp != ~0)
 683     next0 = next0_tmp;
 684   if (next0 == SNAT_IN2OUT_NEXT_DROP || dont_translate)
 685     goto out;
 686
 687   if (PREDICT_TRUE (!ip4_is_fragment (ip0)))
 688     {
 689       sum0 =
 690         ip_incremental_checksum_buffer (vm, b0,
 691                                         (u8 *) icmp0 -
 692                                         (u8 *) vlib_buffer_get_current (b0),
 693                                         ntohs (ip0->length) -
 694                                         ip4_header_bytes (ip0), 0);
 695       checksum0 = ~ip_csum_fold (sum0);
 696       if (PREDICT_FALSE (checksum0 != 0 && checksum0 != 0xffff))
 697         {
 698           next0 = SNAT_IN2OUT_NEXT_DROP;
 699           goto out;
 700         }
 701     }
 702
 703   old_addr0 = ip0->src_address.as_u32;
 704   new_addr0 = ip0->src_address.as_u32 = addr.as_u32;
 705
 706   sum0 = ip0->checksum;
 707   sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 708                          src_address /* changed member */ );
 709   ip0->checksum = ip_csum_fold (sum0);
 710
 711   if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 712     {
 713       if (icmp0->checksum == 0)
 714         icmp0->checksum = 0xffff;
 715
 716       if (!icmp_type_is_error_message (icmp0->type))
 717         {
 718           new_id0 = port;
 719           if (PREDICT_FALSE (new_id0 != echo0->identifier))
 720             {
 721               old_id0 = echo0->identifier;
 722               new_id0 = port;
 723               echo0->identifier = new_id0;
 724
 725               sum0 = icmp0->checksum;
 726               sum0 =
 727                 ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
 728                                 identifier);
 729               icmp0->checksum = ip_csum_fold (sum0);
 730             }
 731         }
 732       else
 733         {
 734           inner_ip0 = (ip4_header_t *) (echo0 + 1);
 735           l4_header = ip4_next_header (inner_ip0);
 736
 737           if (!ip4_header_checksum_is_valid (inner_ip0))
 738             {
 739               next0 = SNAT_IN2OUT_NEXT_DROP;
 740               goto out;
 741             }
 742
 743           /* update inner destination IP address */
 744           old_addr0 = inner_ip0->dst_address.as_u32;
 745           inner_ip0->dst_address = addr;
 746           new_addr0 = inner_ip0->dst_address.as_u32;
 747           sum0 = icmp0->checksum;
 748           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 749                                  dst_address /* changed member */ );
 750           icmp0->checksum = ip_csum_fold (sum0);
 751
 752           /* update inner IP header checksum */
 753           old_checksum0 = inner_ip0->checksum;
 754           sum0 = inner_ip0->checksum;
 755           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 756                                  dst_address /* changed member */ );
 757           inner_ip0->checksum = ip_csum_fold (sum0);
 758           new_checksum0 = inner_ip0->checksum;
 759           sum0 = icmp0->checksum;
 760           sum0 =
 761             ip_csum_update (sum0, old_checksum0, new_checksum0, ip4_header_t,
 762                             checksum);
 763           icmp0->checksum = ip_csum_fold (sum0);
 764
 765           switch (protocol)
 766             {
 767             case NAT_PROTOCOL_ICMP:
 768               inner_icmp0 = (icmp46_header_t *) l4_header;
 769               inner_echo0 = (icmp_echo_header_t *) (inner_icmp0 + 1);
 770
 771               old_id0 = inner_echo0->identifier;
 772               new_id0 = port;
 773               inner_echo0->identifier = new_id0;
 774
 775               sum0 = icmp0->checksum;
 776               sum0 =
 777                 ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
 778                                 identifier);
 779               icmp0->checksum = ip_csum_fold (sum0);
 780               break;
 781             case NAT_PROTOCOL_UDP:
 782             case NAT_PROTOCOL_TCP:
 783               old_id0 = ((tcp_udp_header_t *) l4_header)->dst_port;
 784               new_id0 = port;
 785               ((tcp_udp_header_t *) l4_header)->dst_port = new_id0;
 786
 787               sum0 = icmp0->checksum;
 788               sum0 = ip_csum_update (sum0, old_id0, new_id0, tcp_udp_header_t,
 789                                      dst_port);
 790               icmp0->checksum = ip_csum_fold (sum0);
 791               break;
 792             default:
 793               ASSERT (0);
 794             }
 795         }
 796     }
 797
 798   if (vnet_buffer (b0)->sw_if_index[VLIB_TX] == ~0)
 799     {
 800       if (sm->deterministic ||
 801           0 != snat_icmp_hairpinning (sm, b0, ip0, icmp0,
 802                                       sm->endpoint_dependent))
 803         vnet_buffer (b0)->sw_if_index[VLIB_TX] = fib_index;
 804     }
 805
 806 out:
 807   return next0;
 808 }
 809 #endif
 810
 811 static inline u32
 812 icmp_in2out_slow_path (snat_main_t * sm,
 813                        vlib_buffer_t * b0,
 814                        ip4_header_t * ip0,
 815                        icmp46_header_t * icmp0,
 816                        u32 sw_if_index0,
 817                        u32 rx_fib_index0,
 818                        vlib_node_runtime_t * node,
 819                        u32 next0,
 820                        f64 now, u32 thread_index, snat_session_t ** p_s0)
 821 {
 822   vlib_main_t *vm = vlib_get_main ();
 823
 824   next0 = icmp_in2out (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
 825                        next0, thread_index, p_s0, 0);
 826   snat_session_t *s0 = *p_s0;
 827   if (PREDICT_TRUE (next0 != SNAT_IN2OUT_NEXT_DROP && s0))
 828     {
 829       /* Accounting */
 830       nat44_session_update_counters (s0, now,
 831                                      vlib_buffer_length_in_chain
 832                                      (vm, b0), thread_index);
 833       /* Per-user LRU list maintenance */
 834       nat44_session_update_lru (sm, s0, thread_index);
 835     }
 836   return next0;
 837 }
 838
 839 static int
 840 nat_in2out_sm_unknown_proto (snat_main_t * sm,
 841                              vlib_buffer_t * b,
 842                              ip4_header_t * ip, u32 rx_fib_index)
 843 {
 844   clib_bihash_kv_8_8_t kv, value;
 845   snat_static_mapping_t *m;
 846   u32 old_addr, new_addr;
 847   ip_csum_t sum;
 848
 849   init_nat_k (&kv, ip->src_address, 0, rx_fib_index, 0);
 850   if (clib_bihash_search_8_8 (&sm->static_mapping_by_local, &kv, &value))
 851     return 1;
 852
 853   m = pool_elt_at_index (sm->static_mappings, value.value);
 854
 855   old_addr = ip->src_address.as_u32;
 856   new_addr = ip->src_address.as_u32 = m->external_addr.as_u32;
 857   sum = ip->checksum;
 858   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, src_address);
 859   ip->checksum = ip_csum_fold (sum);
 860
 861
 862   /* Hairpinning */
 863   if (vnet_buffer (b)->sw_if_index[VLIB_TX] == ~0)
 864     {
 865       vnet_buffer (b)->sw_if_index[VLIB_TX] = m->fib_index;
 866       nat_hairpinning_sm_unknown_proto (sm, b, ip);
 867     }
 868
 869   return 0;
 870 }
 871
 872 static inline uword
 873 snat_in2out_node_fn_inline (vlib_main_t * vm,
 874                             vlib_node_runtime_t * node,
 875                             vlib_frame_t * frame, int is_slow_path,
 876                             int is_output_feature)
 877 {
 878   u32 n_left_from, *from, *to_next;
 879   snat_in2out_next_t next_index;
 880   u32 pkts_processed = 0;
 881   snat_main_t *sm = &snat_main;
 882   f64 now = vlib_time_now (vm);
 883   u32 stats_node_index;
 884   u32 thread_index = vm->thread_index;
 885   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 886     0, fragments = 0;
 887
 888   stats_node_index = is_slow_path ? sm->in2out_slowpath_node_index :
 889     sm->in2out_node_index;
 890
 891   from = vlib_frame_vector_args (frame);
 892   n_left_from = frame->n_vectors;
 893   next_index = node->cached_next_index;
 894
 895   while (n_left_from > 0)
 896     {
 897       u32 n_left_to_next;
 898
 899       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 900
 901       while (n_left_from >= 4 && n_left_to_next >= 2)
 902         {
 903           u32 bi0, bi1;
 904           vlib_buffer_t *b0, *b1;
 905           u32 next0, next1;
 906           u32 sw_if_index0, sw_if_index1;
 907           ip4_header_t *ip0, *ip1;
 908           ip_csum_t sum0, sum1;
 909           u32 new_addr0, old_addr0, new_addr1, old_addr1;
 910           u16 old_port0, new_port0, old_port1, new_port1;
 911           udp_header_t *udp0, *udp1;
 912           tcp_header_t *tcp0, *tcp1;
 913           icmp46_header_t *icmp0, *icmp1;
 914           u32 rx_fib_index0, rx_fib_index1;
 915           u32 proto0, proto1;
 916           snat_session_t *s0 = 0, *s1 = 0;
 917           clib_bihash_kv_8_8_t kv0, value0, kv1, value1;
 918           u32 iph_offset0 = 0, iph_offset1 = 0;
 919
 920           /* Prefetch next iteration. */
 921           {
 922             vlib_buffer_t *p2, *p3;
 923
 924             p2 = vlib_get_buffer (vm, from[2]);
 925             p3 = vlib_get_buffer (vm, from[3]);
 926
 927             vlib_prefetch_buffer_header (p2, LOAD);
 928             vlib_prefetch_buffer_header (p3, LOAD);
 929
 930             CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, LOAD);
 931             CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, LOAD);
 932           }
 933
 934           /* speculatively enqueue b0 and b1 to the current next frame */
 935           to_next[0] = bi0 = from[0];
 936           to_next[1] = bi1 = from[1];
 937           from += 2;
 938           to_next += 2;
 939           n_left_from -= 2;
 940           n_left_to_next -= 2;
 941
 942           b0 = vlib_get_buffer (vm, bi0);
 943           b1 = vlib_get_buffer (vm, bi1);
 944
 945           if (is_output_feature)
 946             iph_offset0 = vnet_buffer (b0)->ip.reass.save_rewrite_length;
 947
 948           ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
 949                                   iph_offset0);
 950
 951           udp0 = ip4_next_header (ip0);
 952           tcp0 = (tcp_header_t *) udp0;
 953           icmp0 = (icmp46_header_t *) udp0;
 954
 955           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 956           rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
 957                                    sw_if_index0);
 958
 959           next0 = next1 = SNAT_IN2OUT_NEXT_LOOKUP;
 960
 961           if (PREDICT_FALSE (ip0->ttl == 1))
 962             {
 963               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 964               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 965                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 966                                            0);
 967               next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
 968               goto trace00;
 969             }
 970
 971           proto0 = ip_proto_to_nat_proto (ip0->protocol);
 972
 973           /* Next configured feature, probably ip4-lookup */
 974           if (is_slow_path)
 975             {
 976               if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
 977                 {
 978                   if (nat_in2out_sm_unknown_proto
 979                       (sm, b0, ip0, rx_fib_index0))
 980                     {
 981                       next0 = SNAT_IN2OUT_NEXT_DROP;
 982                       b0->error =
 983                         node->errors[SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL];
 984                     }
 985                   other_packets++;
 986                   goto trace00;
 987                 }
 988
 989               if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
 990                 {
 991                   next0 = icmp_in2out_slow_path
 992                     (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0,
 993                      node, next0, now, thread_index, &s0);
 994                   icmp_packets++;
 995                   goto trace00;
 996                 }
 997             }
 998           else
 999             {
1000               if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
1001                 {
1002                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1003                   goto trace00;
1004                 }
1005
1006               if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
1007                 {
1008                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1009                   goto trace00;
1010                 }
1011             }
1012
1013           init_nat_k (&kv0, ip0->src_address,
1014                       vnet_buffer (b0)->ip.reass.l4_src_port, rx_fib_index0,
1015                       proto0);
1016           if (PREDICT_FALSE
1017               (clib_bihash_search_8_8
1018                (&sm->per_thread_data[thread_index].in2out, &kv0,
1019                 &value0) != 0))
1020             {
1021               if (is_slow_path)
1022                 {
1023                   if (is_output_feature)
1024                     {
1025                       if (PREDICT_FALSE
1026                           (nat_not_translate_output_feature
1027                            (sm, ip0, proto0,
1028                             vnet_buffer (b0)->ip.reass.l4_src_port,
1029                             vnet_buffer (b0)->ip.reass.l4_dst_port,
1030                             thread_index, sw_if_index0)))
1031                         goto trace00;
1032
1033                       /*
1034                        * Send DHCP packets to the ipv4 stack, or we won't
1035                        * be able to use dhcp client on the outside interface
1036                        */
1037                       if (PREDICT_FALSE
1038                           (proto0 == NAT_PROTOCOL_UDP
1039                            && (vnet_buffer (b0)->ip.reass.l4_dst_port ==
1040                                clib_host_to_net_u16
1041                                (UDP_DST_PORT_dhcp_to_server))
1042                            && ip0->dst_address.as_u32 == 0xffffffff))
1043                         goto trace00;
1044                     }
1045                   else
1046                     {
1047                       if (PREDICT_FALSE
1048                           (snat_not_translate
1049                            (sm, node, sw_if_index0, ip0, proto0,
1050                             rx_fib_index0, thread_index)))
1051                         goto trace00;
1052                     }
1053
1054                   next0 = slow_path (sm, b0, ip0,
1055                                      ip0->src_address,
1056                                      vnet_buffer (b0)->ip.reass.l4_src_port,
1057                                      rx_fib_index0,
1058                                      proto0,
1059                                      &s0, node, next0, thread_index, now);
1060                   if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
1061                     goto trace00;
1062
1063                   if (PREDICT_FALSE (!s0))
1064                     goto trace00;
1065                 }
1066               else
1067                 {
1068                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1069                   goto trace00;
1070                 }
1071             }
1072           else
1073             s0 =
1074               pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
1075                                  value0.value);
1076
1077           b0->flags |= VNET_BUFFER_F_IS_NATED;
1078
1079           old_addr0 = ip0->src_address.as_u32;
1080           ip0->src_address = s0->out2in.addr;
1081           new_addr0 = ip0->src_address.as_u32;
1082           if (!is_output_feature)
1083             vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
1084
1085           sum0 = ip0->checksum;
1086           sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1087                                  ip4_header_t,
1088                                  src_address /* changed member */ );
1089           ip0->checksum = ip_csum_fold (sum0);
1090
1091
1092           if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
1093             {
1094               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1095                 {
1096                   old_port0 = vnet_buffer (b0)->ip.reass.l4_src_port;
1097                   new_port0 = udp0->src_port = s0->out2in.port;
1098                   sum0 = tcp0->checksum;
1099                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1100                                          ip4_header_t,
1101                                          dst_address /* changed member */ );
1102                   sum0 = ip_csum_update (sum0, old_port0, new_port0,
1103                                          ip4_header_t /* cheat */ ,
1104                                          length /* changed member */ );
1105                   mss_clamping (sm->mss_clamping, tcp0, &sum0);
1106                   tcp0->checksum = ip_csum_fold (sum0);
1107                 }
1108               tcp_packets++;
1109             }
1110           else
1111             {
1112               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1113                 {
1114                   udp0->src_port = s0->out2in.port;
1115                   if (PREDICT_FALSE (udp0->checksum))
1116                     {
1117                       old_port0 = vnet_buffer (b0)->ip.reass.l4_src_port;
1118                       new_port0 = udp0->src_port;
1119                       sum0 = udp0->checksum;
1120                       sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t, dst_address      /* changed member */
1121                         );
1122                       sum0 =
1123                         ip_csum_update (sum0, old_port0, new_port0,
1124                                         ip4_header_t /* cheat */ ,
1125                                         length /* changed member */ );
1126                       udp0->checksum = ip_csum_fold (sum0);
1127                     }
1128                 }
1129               udp_packets++;
1130             }
1131
1132           /* Accounting */
1133           nat44_session_update_counters (s0, now,
1134                                          vlib_buffer_length_in_chain (vm, b0),
1135                                          thread_index);
1136           /* Per-user LRU list maintenance */
1137           nat44_session_update_lru (sm, s0, thread_index);
1138         trace00:
1139
1140           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1141                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1142             {
1143               snat_in2out_trace_t *t =
1144                 vlib_add_trace (vm, node, b0, sizeof (*t));
1145               t->is_slow_path = is_slow_path;
1146               t->sw_if_index = sw_if_index0;
1147               t->next_index = next0;
1148               t->session_index = ~0;
1149               if (s0)
1150                 t->session_index =
1151                   s0 - sm->per_thread_data[thread_index].sessions;
1152             }
1153
1154           pkts_processed += next0 == SNAT_IN2OUT_NEXT_LOOKUP;
1155
1156           if (is_output_feature)
1157             iph_offset1 = vnet_buffer (b1)->ip.reass.save_rewrite_length;
1158
1159           ip1 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b1) +
1160                                   iph_offset1);
1161
1162           udp1 = ip4_next_header (ip1);
1163           tcp1 = (tcp_header_t *) udp1;
1164           icmp1 = (icmp46_header_t *) udp1;
1165
1166           sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];
1167           rx_fib_index1 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
1168                                    sw_if_index1);
1169
1170           if (PREDICT_FALSE (ip1->ttl == 1))
1171             {
1172               vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1173               icmp4_error_set_vnet_buffer (b1, ICMP4_time_exceeded,
1174                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1175                                            0);
1176               next1 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
1177               goto trace01;
1178             }
1179
1180           proto1 = ip_proto_to_nat_proto (ip1->protocol);
1181
1182           /* Next configured feature, probably ip4-lookup */
1183           if (is_slow_path)
1184             {
1185               if (PREDICT_FALSE (proto1 == NAT_PROTOCOL_OTHER))
1186                 {
1187                   if (nat_in2out_sm_unknown_proto
1188                       (sm, b1, ip1, rx_fib_index1))
1189                     {
1190                       next1 = SNAT_IN2OUT_NEXT_DROP;
1191                       b1->error =
1192                         node->errors[SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL];
1193                     }
1194                   other_packets++;
1195                   goto trace01;
1196                 }
1197
1198               if (PREDICT_FALSE (proto1 == NAT_PROTOCOL_ICMP))
1199                 {
1200                   next1 = icmp_in2out_slow_path
1201                     (sm, b1, ip1, icmp1, sw_if_index1, rx_fib_index1, node,
1202                      next1, now, thread_index, &s1);
1203                   icmp_packets++;
1204                   goto trace01;
1205                 }
1206             }
1207           else
1208             {
1209               if (PREDICT_FALSE (proto1 == NAT_PROTOCOL_OTHER))
1210                 {
1211                   next1 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1212                   goto trace01;
1213                 }
1214
1215               if (PREDICT_FALSE (proto1 == NAT_PROTOCOL_ICMP))
1216                 {
1217                   next1 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1218                   goto trace01;
1219                 }
1220             }
1221
1222           init_nat_k (&kv1, ip1->src_address,
1223                       vnet_buffer (b1)->ip.reass.l4_src_port, rx_fib_index1,
1224                       proto1);
1225           if (PREDICT_FALSE
1226               (clib_bihash_search_8_8
1227                (&sm->per_thread_data[thread_index].in2out, &kv1,
1228                 &value1) != 0))
1229             {
1230               if (is_slow_path)
1231                 {
1232                   if (is_output_feature)
1233                     {
1234                       if (PREDICT_FALSE
1235                           (nat_not_translate_output_feature
1236                            (sm, ip1, proto1,
1237                             vnet_buffer (b1)->ip.reass.l4_src_port,
1238                             vnet_buffer (b1)->ip.reass.l4_dst_port,
1239                             thread_index, sw_if_index1)))
1240                         goto trace01;
1241
1242                       /*
1243                        * Send DHCP packets to the ipv4 stack, or we won't
1244                        * be able to use dhcp client on the outside interface
1245                        */
1246                       if (PREDICT_FALSE
1247                           (proto1 == NAT_PROTOCOL_UDP
1248                            && (vnet_buffer (b1)->ip.reass.l4_dst_port ==
1249                                clib_host_to_net_u16
1250                                (UDP_DST_PORT_dhcp_to_server))
1251                            && ip1->dst_address.as_u32 == 0xffffffff))
1252                         goto trace01;
1253                     }
1254                   else
1255                     {
1256                       if (PREDICT_FALSE
1257                           (snat_not_translate
1258                            (sm, node, sw_if_index1, ip1, proto1,
1259                             rx_fib_index1, thread_index)))
1260                         goto trace01;
1261                     }
1262
1263                   next1 =
1264                     slow_path (sm, b1, ip1, ip1->src_address,
1265                                vnet_buffer (b1)->ip.reass.l4_src_port,
1266                                rx_fib_index1, proto1, &s1, node, next1,
1267                                thread_index, now);
1268                   if (PREDICT_FALSE (next1 == SNAT_IN2OUT_NEXT_DROP))
1269                     goto trace01;
1270
1271                   if (PREDICT_FALSE (!s1))
1272                     goto trace01;
1273                 }
1274               else
1275                 {
1276                   next1 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1277                   goto trace01;
1278                 }
1279             }
1280           else
1281             s1 =
1282               pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
1283                                  value1.value);
1284
1285           b1->flags |= VNET_BUFFER_F_IS_NATED;
1286
1287           old_addr1 = ip1->src_address.as_u32;
1288           ip1->src_address = s1->out2in.addr;
1289           new_addr1 = ip1->src_address.as_u32;
1290           if (!is_output_feature)
1291             vnet_buffer (b1)->sw_if_index[VLIB_TX] = s1->out2in.fib_index;
1292
1293           sum1 = ip1->checksum;
1294           sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
1295                                  ip4_header_t,
1296                                  src_address /* changed member */ );
1297           ip1->checksum = ip_csum_fold (sum1);
1298
1299           if (PREDICT_TRUE (proto1 == NAT_PROTOCOL_TCP))
1300             {
1301               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1302                 {
1303                   old_port1 = vnet_buffer (b1)->ip.reass.l4_src_port;
1304                   new_port1 = udp1->src_port = s1->out2in.port;
1305                   sum1 = tcp1->checksum;
1306                   sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
1307                                          ip4_header_t,
1308                                          dst_address /* changed member */ );
1309                   sum1 = ip_csum_update (sum1, old_port1, new_port1,
1310                                          ip4_header_t /* cheat */ ,
1311                                          length /* changed member */ );
1312                   mss_clamping (sm->mss_clamping, tcp1, &sum1);
1313                   tcp1->checksum = ip_csum_fold (sum1);
1314                 }
1315               tcp_packets++;
1316             }
1317           else
1318             {
1319               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1320                 {
1321                   udp1->src_port = s1->out2in.port;
1322                   if (PREDICT_FALSE (udp1->checksum))
1323                     {
1324                       old_port1 = vnet_buffer (b1)->ip.reass.l4_src_port;
1325                       new_port1 = udp1->src_port;
1326                       sum1 = udp1->checksum;
1327                       sum1 = ip_csum_update (sum1, old_addr1, new_addr1, ip4_header_t, dst_address      /* changed member */
1328                         );
1329                       sum1 =
1330                         ip_csum_update (sum1, old_port1, new_port1,
1331                                         ip4_header_t /* cheat */ ,
1332                                         length /* changed member */ );
1333                       udp1->checksum = ip_csum_fold (sum1);
1334                     }
1335                 }
1336               udp_packets++;
1337             }
1338
1339           /* Accounting */
1340           nat44_session_update_counters (s1, now,
1341                                          vlib_buffer_length_in_chain (vm, b1),
1342                                          thread_index);
1343           /* Per-user LRU list maintenance */
1344           nat44_session_update_lru (sm, s1, thread_index);
1345         trace01:
1346
1347           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1348                              && (b1->flags & VLIB_BUFFER_IS_TRACED)))
1349             {
1350               snat_in2out_trace_t *t =
1351                 vlib_add_trace (vm, node, b1, sizeof (*t));
1352               t->sw_if_index = sw_if_index1;
1353               t->next_index = next1;
1354               t->session_index = ~0;
1355               if (s1)
1356                 t->session_index =
1357                   s1 - sm->per_thread_data[thread_index].sessions;
1358             }
1359
1360           pkts_processed += next1 == SNAT_IN2OUT_NEXT_LOOKUP;
1361
1362           /* verify speculative enqueues, maybe switch current next frame */
1363           vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
1364                                            to_next, n_left_to_next,
1365                                            bi0, bi1, next0, next1);
1366         }
1367
1368       while (n_left_from > 0 && n_left_to_next > 0)
1369         {
1370           u32 bi0;
1371           vlib_buffer_t *b0;
1372           u32 next0;
1373           u32 sw_if_index0;
1374           ip4_header_t *ip0;
1375           ip_csum_t sum0;
1376           u32 new_addr0, old_addr0;
1377           u16 old_port0, new_port0;
1378           udp_header_t *udp0;
1379           tcp_header_t *tcp0;
1380           icmp46_header_t *icmp0;
1381           u32 rx_fib_index0;
1382           u32 proto0;
1383           snat_session_t *s0 = 0;
1384           clib_bihash_kv_8_8_t kv0, value0;
1385           u32 iph_offset0 = 0;
1386
1387           /* speculatively enqueue b0 to the current next frame */
1388           bi0 = from[0];
1389           to_next[0] = bi0;
1390           from += 1;
1391           to_next += 1;
1392           n_left_from -= 1;
1393           n_left_to_next -= 1;
1394
1395           b0 = vlib_get_buffer (vm, bi0);
1396           next0 = SNAT_IN2OUT_NEXT_LOOKUP;
1397
1398           if (is_output_feature)
1399             iph_offset0 = vnet_buffer (b0)->ip.reass.save_rewrite_length;
1400
1401           ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
1402                                   iph_offset0);
1403
1404           udp0 = ip4_next_header (ip0);
1405           tcp0 = (tcp_header_t *) udp0;
1406           icmp0 = (icmp46_header_t *) udp0;
1407
1408           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1409           rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
1410                                    sw_if_index0);
1411
1412           if (PREDICT_FALSE (ip0->ttl == 1))
1413             {
1414               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1415               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1416                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1417                                            0);
1418               next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
1419               goto trace0;
1420             }
1421
1422           proto0 = ip_proto_to_nat_proto (ip0->protocol);
1423
1424           /* Next configured feature, probably ip4-lookup */
1425           if (is_slow_path)
1426             {
1427               if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
1428                 {
1429                   if (nat_in2out_sm_unknown_proto
1430                       (sm, b0, ip0, rx_fib_index0))
1431                     {
1432                       next0 = SNAT_IN2OUT_NEXT_DROP;
1433                       b0->error =
1434                         node->errors[SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL];
1435                     }
1436                   other_packets++;
1437                   goto trace0;
1438                 }
1439
1440               if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
1441                 {
1442                   next0 = icmp_in2out_slow_path
1443                     (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1444                      next0, now, thread_index, &s0);
1445                   icmp_packets++;
1446                   goto trace0;
1447                 }
1448             }
1449           else
1450             {
1451               if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
1452                 {
1453                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1454                   goto trace0;
1455                 }
1456
1457               if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
1458                 {
1459                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1460                   goto trace0;
1461                 }
1462             }
1463
1464           init_nat_k (&kv0, ip0->src_address,
1465                       vnet_buffer (b0)->ip.reass.l4_src_port, rx_fib_index0,
1466                       proto0);
1467
1468           if (clib_bihash_search_8_8
1469               (&sm->per_thread_data[thread_index].in2out, &kv0, &value0))
1470             {
1471               if (is_slow_path)
1472                 {
1473                   if (is_output_feature)
1474                     {
1475                       if (PREDICT_FALSE
1476                           (nat_not_translate_output_feature
1477                            (sm, ip0, proto0,
1478                             vnet_buffer (b0)->ip.reass.l4_src_port,
1479                             vnet_buffer (b0)->ip.reass.l4_dst_port,
1480                             thread_index, sw_if_index0)))
1481                         goto trace0;
1482
1483                       /*
1484                        * Send DHCP packets to the ipv4 stack, or we won't
1485                        * be able to use dhcp client on the outside interface
1486                        */
1487                       if (PREDICT_FALSE
1488                           (proto0 == NAT_PROTOCOL_UDP
1489                            && (vnet_buffer (b0)->ip.reass.l4_dst_port ==
1490                                clib_host_to_net_u16
1491                                (UDP_DST_PORT_dhcp_to_server))
1492                            && ip0->dst_address.as_u32 == 0xffffffff))
1493                         goto trace0;
1494                     }
1495                   else
1496                     {
1497                       if (PREDICT_FALSE
1498                           (snat_not_translate
1499                            (sm, node, sw_if_index0, ip0, proto0,
1500                             rx_fib_index0, thread_index)))
1501                         goto trace0;
1502                     }
1503
1504                   next0 = slow_path (sm, b0, ip0,
1505                                      ip0->src_address,
1506                                      vnet_buffer (b0)->ip.reass.l4_src_port,
1507                                      rx_fib_index0,
1508                                      proto0,
1509                                      &s0, node, next0, thread_index, now);
1510
1511                   if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
1512                     goto trace0;
1513
1514                   if (PREDICT_FALSE (!s0))
1515                     goto trace0;
1516                 }
1517               else
1518                 {
1519                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1520                   goto trace0;
1521                 }
1522             }
1523           else
1524             s0 =
1525               pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
1526                                  value0.value);
1527
1528           b0->flags |= VNET_BUFFER_F_IS_NATED;
1529
1530           old_addr0 = ip0->src_address.as_u32;
1531           ip0->src_address = s0->out2in.addr;
1532           new_addr0 = ip0->src_address.as_u32;
1533           if (!is_output_feature)
1534             vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
1535
1536           sum0 = ip0->checksum;
1537           sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1538                                  ip4_header_t,
1539                                  src_address /* changed member */ );
1540           ip0->checksum = ip_csum_fold (sum0);
1541
1542           if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
1543             {
1544               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1545                 {
1546                   old_port0 = vnet_buffer (b0)->ip.reass.l4_src_port;
1547                   new_port0 = udp0->src_port = s0->out2in.port;
1548                   sum0 = tcp0->checksum;
1549                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1550                                          ip4_header_t,
1551                                          dst_address /* changed member */ );
1552                   sum0 = ip_csum_update (sum0, old_port0, new_port0,
1553                                          ip4_header_t /* cheat */ ,
1554                                          length /* changed member */ );
1555                   mss_clamping (sm->mss_clamping, tcp0, &sum0);
1556                   tcp0->checksum = ip_csum_fold (sum0);
1557                 }
1558               tcp_packets++;
1559             }
1560           else
1561             {
1562               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1563                 {
1564                   udp0->src_port = s0->out2in.port;
1565                   if (PREDICT_FALSE (udp0->checksum))
1566                     {
1567                       old_port0 = vnet_buffer (b0)->ip.reass.l4_src_port;
1568                       new_port0 = udp0->src_port;
1569                       sum0 = udp0->checksum;
1570                       sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t, dst_address      /* changed member */
1571                         );
1572                       sum0 =
1573                         ip_csum_update (sum0, old_port0, new_port0,
1574                                         ip4_header_t /* cheat */ ,
1575                                         length /* changed member */ );
1576                       udp0->checksum = ip_csum_fold (sum0);
1577                     }
1578                 }
1579               udp_packets++;
1580             }
1581
1582           /* Accounting */
1583           nat44_session_update_counters (s0, now,
1584                                          vlib_buffer_length_in_chain (vm, b0),
1585                                          thread_index);
1586           /* Per-user LRU list maintenance */
1587           nat44_session_update_lru (sm, s0, thread_index);
1588
1589         trace0:
1590           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1591                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1592             {
1593               snat_in2out_trace_t *t =
1594                 vlib_add_trace (vm, node, b0, sizeof (*t));
1595               t->is_slow_path = is_slow_path;
1596               t->sw_if_index = sw_if_index0;
1597               t->next_index = next0;
1598               t->session_index = ~0;
1599               if (s0)
1600                 t->session_index =
1601                   s0 - sm->per_thread_data[thread_index].sessions;
1602             }
1603
1604           pkts_processed += next0 == SNAT_IN2OUT_NEXT_LOOKUP;
1605
1606           /* verify speculative enqueue, maybe switch current next frame */
1607           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1608                                            to_next, n_left_to_next,
1609                                            bi0, next0);
1610         }
1611
1612       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1613     }
1614
1615   vlib_node_increment_counter (vm, stats_node_index,
1616                                SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
1617                                pkts_processed);
1618   vlib_node_increment_counter (vm, stats_node_index,
1619                                SNAT_IN2OUT_ERROR_TCP_PACKETS, tcp_packets);
1620   vlib_node_increment_counter (vm, stats_node_index,
1621                                SNAT_IN2OUT_ERROR_UDP_PACKETS, udp_packets);
1622   vlib_node_increment_counter (vm, stats_node_index,
1623                                SNAT_IN2OUT_ERROR_ICMP_PACKETS, icmp_packets);
1624   vlib_node_increment_counter (vm, stats_node_index,
1625                                SNAT_IN2OUT_ERROR_OTHER_PACKETS,
1626                                other_packets);
1627   vlib_node_increment_counter (vm, stats_node_index,
1628                                SNAT_IN2OUT_ERROR_FRAGMENTS, fragments);
1629
1630   return frame->n_vectors;
1631 }
1632
1633 VLIB_NODE_FN (snat_in2out_node) (vlib_main_t * vm,
1634                                  vlib_node_runtime_t * node,
1635                                  vlib_frame_t * frame)
1636 {
1637   return snat_in2out_node_fn_inline (vm, node, frame, 0 /* is_slow_path */ ,
1638                                      0);
1639 }
1640
1641 /* *INDENT-OFF* */
1642 VLIB_REGISTER_NODE (snat_in2out_node) = {
1643   .name = "nat44-in2out",
1644   .vector_size = sizeof (u32),
1645   .format_trace = format_snat_in2out_trace,
1646   .type = VLIB_NODE_TYPE_INTERNAL,
1647
1648   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
1649   .error_strings = snat_in2out_error_strings,
1650
1651   .runtime_data_bytes = sizeof (snat_runtime_t),
1652
1653   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
1654
1655   /* edit / add dispositions here */
1656   .next_nodes = {
1657     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
1658     [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
1659     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
1660     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1661   },
1662 };
1663 /* *INDENT-ON* */
1664
1665 VLIB_NODE_FN (snat_in2out_output_node) (vlib_main_t * vm,
1666                                         vlib_node_runtime_t * node,
1667                                         vlib_frame_t * frame)
1668 {
1669   return snat_in2out_node_fn_inline (vm, node, frame, 0 /* is_slow_path */ ,
1670                                      1);
1671 }
1672
1673 /* *INDENT-OFF* */
1674 VLIB_REGISTER_NODE (snat_in2out_output_node) = {
1675   .name = "nat44-in2out-output",
1676   .vector_size = sizeof (u32),
1677   .format_trace = format_snat_in2out_trace,
1678   .type = VLIB_NODE_TYPE_INTERNAL,
1679
1680   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
1681   .error_strings = snat_in2out_error_strings,
1682
1683   .runtime_data_bytes = sizeof (snat_runtime_t),
1684
1685   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
1686
1687   /* edit / add dispositions here */
1688   .next_nodes = {
1689     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
1690     [SNAT_IN2OUT_NEXT_LOOKUP] = "interface-output",
1691     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-output-slowpath",
1692     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1693   },
1694 };
1695 /* *INDENT-ON* */
1696
1697 VLIB_NODE_FN (snat_in2out_slowpath_node) (vlib_main_t * vm,
1698                                           vlib_node_runtime_t * node,
1699                                           vlib_frame_t * frame)
1700 {
1701   return snat_in2out_node_fn_inline (vm, node, frame, 1 /* is_slow_path */ ,
1702                                      0);
1703 }
1704
1705 /* *INDENT-OFF* */
1706 VLIB_REGISTER_NODE (snat_in2out_slowpath_node) = {
1707   .name = "nat44-in2out-slowpath",
1708   .vector_size = sizeof (u32),
1709   .format_trace = format_snat_in2out_trace,
1710   .type = VLIB_NODE_TYPE_INTERNAL,
1711
1712   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
1713   .error_strings = snat_in2out_error_strings,
1714
1715   .runtime_data_bytes = sizeof (snat_runtime_t),
1716
1717   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
1718
1719   /* edit / add dispositions here */
1720   .next_nodes = {
1721     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
1722     [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
1723     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
1724     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1725   },
1726 };
1727 /* *INDENT-ON* */
1728
1729 VLIB_NODE_FN (snat_in2out_output_slowpath_node) (vlib_main_t * vm,
1730                                                  vlib_node_runtime_t * node,
1731                                                  vlib_frame_t * frame)
1732 {
1733   return snat_in2out_node_fn_inline (vm, node, frame, 1 /* is_slow_path */ ,
1734                                      1);
1735 }
1736
1737 /* *INDENT-OFF* */
1738 VLIB_REGISTER_NODE (snat_in2out_output_slowpath_node) = {
1739   .name = "nat44-in2out-output-slowpath",
1740   .vector_size = sizeof (u32),
1741   .format_trace = format_snat_in2out_trace,
1742   .type = VLIB_NODE_TYPE_INTERNAL,
1743
1744   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
1745   .error_strings = snat_in2out_error_strings,
1746
1747   .runtime_data_bytes = sizeof (snat_runtime_t),
1748
1749   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
1750
1751   /* edit / add dispositions here */
1752   .next_nodes = {
1753     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
1754     [SNAT_IN2OUT_NEXT_LOOKUP] = "interface-output",
1755     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-output-slowpath",
1756     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1757   },
1758 };
1759 /* *INDENT-ON* */
1760
1761 VLIB_NODE_FN (snat_in2out_fast_node) (vlib_main_t * vm,
1762                                       vlib_node_runtime_t * node,
1763                                       vlib_frame_t * frame)
1764 {
1765   u32 n_left_from, *from, *to_next;
1766   snat_in2out_next_t next_index;
1767   u32 pkts_processed = 0;
1768   snat_main_t *sm = &snat_main;
1769   u32 stats_node_index;
1770   int is_hairpinning = 0;
1771
1772   stats_node_index = sm->in2out_fast_node_index;
1773
1774   from = vlib_frame_vector_args (frame);
1775   n_left_from = frame->n_vectors;
1776   next_index = node->cached_next_index;
1777
1778   while (n_left_from > 0)
1779     {
1780       u32 n_left_to_next;
1781
1782       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1783
1784       while (n_left_from > 0 && n_left_to_next > 0)
1785         {
1786           u32 bi0;
1787           vlib_buffer_t *b0;
1788           u32 next0;
1789           u32 sw_if_index0;
1790           ip4_header_t *ip0;
1791           ip_csum_t sum0;
1792           u32 new_addr0, old_addr0;
1793           u16 old_port0, new_port0;
1794           udp_header_t *udp0;
1795           tcp_header_t *tcp0;
1796           icmp46_header_t *icmp0;
1797           u32 proto0;
1798           u32 rx_fib_index0;
1799           ip4_address_t sm0_addr;
1800           u16 sm0_port;
1801           u32 sm0_fib_index;
1802
1803
1804           /* speculatively enqueue b0 to the current next frame */
1805           bi0 = from[0];
1806           to_next[0] = bi0;
1807           from += 1;
1808           to_next += 1;
1809           n_left_from -= 1;
1810           n_left_to_next -= 1;
1811
1812           b0 = vlib_get_buffer (vm, bi0);
1813           next0 = SNAT_IN2OUT_NEXT_LOOKUP;
1814
1815           ip0 = vlib_buffer_get_current (b0);
1816           udp0 = ip4_next_header (ip0);
1817           tcp0 = (tcp_header_t *) udp0;
1818           icmp0 = (icmp46_header_t *) udp0;
1819
1820           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1821           rx_fib_index0 =
1822             ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
1823
1824           if (PREDICT_FALSE (ip0->ttl == 1))
1825             {
1826               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1827               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1828                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1829                                            0);
1830               next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
1831               goto trace0;
1832             }
1833
1834           proto0 = ip_proto_to_nat_proto (ip0->protocol);
1835
1836           if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
1837             goto trace0;
1838
1839           if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
1840             {
1841               next0 = icmp_in2out (sm, b0, ip0, icmp0, sw_if_index0,
1842                                    rx_fib_index0, node, next0, ~0, 0, 0);
1843               goto trace0;
1844             }
1845
1846           if (snat_static_mapping_match
1847               (sm, ip0->src_address, udp0->src_port, rx_fib_index0, proto0,
1848                &sm0_addr, &sm0_port, &sm0_fib_index, 0, 0, 0, 0, 0, 0))
1849             {
1850               b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
1851               next0 = SNAT_IN2OUT_NEXT_DROP;
1852               goto trace0;
1853             }
1854
1855           new_addr0 = sm0_addr.as_u32;
1856           new_port0 = sm0_port;
1857           vnet_buffer (b0)->sw_if_index[VLIB_TX] = sm0_fib_index;
1858           old_addr0 = ip0->src_address.as_u32;
1859           ip0->src_address.as_u32 = new_addr0;
1860
1861           sum0 = ip0->checksum;
1862           sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1863                                  ip4_header_t,
1864                                  src_address /* changed member */ );
1865           ip0->checksum = ip_csum_fold (sum0);
1866
1867           if (PREDICT_FALSE (new_port0 != udp0->dst_port))
1868             {
1869               old_port0 = udp0->src_port;
1870               udp0->src_port = new_port0;
1871
1872               if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
1873                 {
1874                   sum0 = tcp0->checksum;
1875                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1876                                          ip4_header_t,
1877                                          dst_address /* changed member */ );
1878                   sum0 = ip_csum_update (sum0, old_port0, new_port0,
1879                                          ip4_header_t /* cheat */ ,
1880                                          length /* changed member */ );
1881                   mss_clamping (sm->mss_clamping, tcp0, &sum0);
1882                   tcp0->checksum = ip_csum_fold (sum0);
1883                 }
1884               else if (udp0->checksum)
1885                 {
1886                   sum0 = udp0->checksum;
1887                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1888                                          ip4_header_t,
1889                                          dst_address /* changed member */ );
1890                   sum0 = ip_csum_update (sum0, old_port0, new_port0,
1891                                          ip4_header_t /* cheat */ ,
1892                                          length /* changed member */ );
1893                   udp0->checksum = ip_csum_fold (sum0);
1894                 }
1895             }
1896           else
1897             {
1898               if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
1899                 {
1900                   sum0 = tcp0->checksum;
1901                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1902                                          ip4_header_t,
1903                                          dst_address /* changed member */ );
1904                   mss_clamping (sm->mss_clamping, tcp0, &sum0);
1905                   tcp0->checksum = ip_csum_fold (sum0);
1906                 }
1907               else if (udp0->checksum)
1908                 {
1909                   sum0 = udp0->checksum;
1910                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1911                                          ip4_header_t,
1912                                          dst_address /* changed member */ );
1913                   udp0->checksum = ip_csum_fold (sum0);
1914                 }
1915             }
1916
1917           /* Hairpinning */
1918           snat_hairpinning (vm, node, sm, b0, ip0, udp0, tcp0, proto0, 0,
1919                             0 /* do_trace */ );
1920           is_hairpinning = 1;
1921
1922         trace0:
1923           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1924                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1925             {
1926               snat_in2out_trace_t *t =
1927                 vlib_add_trace (vm, node, b0, sizeof (*t));
1928               t->sw_if_index = sw_if_index0;
1929               t->next_index = next0;
1930               t->is_hairpinning = is_hairpinning;
1931             }
1932
1933           pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
1934
1935           /* verify speculative enqueue, maybe switch current next frame */
1936           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1937                                            to_next, n_left_to_next,
1938                                            bi0, next0);
1939         }
1940
1941       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1942     }
1943
1944   vlib_node_increment_counter (vm, stats_node_index,
1945                                SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
1946                                pkts_processed);
1947   return frame->n_vectors;
1948 }
1949
1950
1951 /* *INDENT-OFF* */
1952 VLIB_REGISTER_NODE (snat_in2out_fast_node) = {
1953   .name = "nat44-in2out-fast",
1954   .vector_size = sizeof (u32),
1955   .format_trace = format_snat_in2out_fast_trace,
1956   .type = VLIB_NODE_TYPE_INTERNAL,
1957
1958   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
1959   .error_strings = snat_in2out_error_strings,
1960
1961   .runtime_data_bytes = sizeof (snat_runtime_t),
1962
1963   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
1964
1965   /* edit / add dispositions here */
1966   .next_nodes = {
1967     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
1968     [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
1969     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
1970     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1971   },
1972 };
1973 /* *INDENT-ON* */
1974
1975 /*
1976  * fd.io coding-style-patch-verification: ON
1977  *
1978  * Local Variables:
1979  * eval: (c-set-style "gnu")
1980  * End:
1981  */