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