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
  39 typedef struct
  40 {
  41   u32 sw_if_index;
  42   u32 next_index;
  43   u32 session_index;
  44   u32 is_slow_path;
  45 } snat_in2out_trace_t;
  46
  47 /* packet trace format function */
  48 static u8 *
  49 format_snat_in2out_trace (u8 * s, va_list * args)
  50 {
  51   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  52   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  53   snat_in2out_trace_t *t = va_arg (*args, snat_in2out_trace_t *);
  54   char *tag;
  55
  56   tag = t->is_slow_path ? "NAT44_IN2OUT_SLOW_PATH" : "NAT44_IN2OUT_FAST_PATH";
  57
  58   s = format (s, "%s: sw_if_index %d, next index %d, session %d", tag,
  59               t->sw_if_index, t->next_index, t->session_index);
  60
  61   return s;
  62 }
  63
  64 static u8 *
  65 format_snat_in2out_fast_trace (u8 * s, va_list * args)
  66 {
  67   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  68   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  69   snat_in2out_trace_t *t = va_arg (*args, snat_in2out_trace_t *);
  70
  71   s = format (s, "NAT44_IN2OUT_FAST: sw_if_index %d, next index %d",
  72               t->sw_if_index, t->next_index);
  73
  74   return s;
  75 }
  76
  77 #define foreach_snat_in2out_error                       \
  78 _(UNSUPPORTED_PROTOCOL, "unsupported protocol")         \
  79 _(IN2OUT_PACKETS, "good in2out packets processed")      \
  80 _(OUT_OF_PORTS, "out of ports")                         \
  81 _(BAD_OUTSIDE_FIB, "outside VRF ID not found")          \
  82 _(BAD_ICMP_TYPE, "unsupported ICMP type")               \
  83 _(NO_TRANSLATION, "no translation")                     \
  84 _(MAX_SESSIONS_EXCEEDED, "maximum sessions exceeded")   \
  85 _(DROP_FRAGMENT, "drop fragment")                       \
  86 _(TCP_PACKETS, "TCP packets")                           \
  87 _(UDP_PACKETS, "UDP packets")                           \
  88 _(ICMP_PACKETS, "ICMP packets")                         \
  89 _(OTHER_PACKETS, "other protocol packets")              \
  90 _(FRAGMENTS, "fragments")                               \
  91 _(CACHED_FRAGMENTS, "cached fragments")                 \
  92 _(PROCESSED_FRAGMENTS, "processed fragments")
  93
  94 typedef enum
  95 {
  96 #define _(sym,str) SNAT_IN2OUT_ERROR_##sym,
  97   foreach_snat_in2out_error
  98 #undef _
  99     SNAT_IN2OUT_N_ERROR,
 100 } snat_in2out_error_t;
 101
 102 static char *snat_in2out_error_strings[] = {
 103 #define _(sym,string) string,
 104   foreach_snat_in2out_error
 105 #undef _
 106 };
 107
 108 typedef enum
 109 {
 110   SNAT_IN2OUT_NEXT_LOOKUP,
 111   SNAT_IN2OUT_NEXT_DROP,
 112   SNAT_IN2OUT_NEXT_ICMP_ERROR,
 113   SNAT_IN2OUT_NEXT_SLOW_PATH,
 114   SNAT_IN2OUT_N_NEXT,
 115 } snat_in2out_next_t;
 116
 117 static inline int
 118 snat_not_translate (snat_main_t * sm, vlib_node_runtime_t * node,
 119                     u32 sw_if_index0, ip4_header_t * ip0, u32 proto0,
 120                     u32 rx_fib_index0, u32 thread_index)
 121 {
 122   udp_header_t *udp0 = ip4_next_header (ip0);
 123   snat_session_key_t key0, sm0;
 124   clib_bihash_kv_8_8_t kv0, value0;
 125
 126   key0.addr = ip0->dst_address;
 127   key0.port = udp0->dst_port;
 128   key0.protocol = proto0;
 129   key0.fib_index = sm->outside_fib_index;
 130   kv0.key = key0.as_u64;
 131
 132   /* NAT packet aimed at external address if */
 133   /* has active sessions */
 134   if (clib_bihash_search_8_8 (&sm->per_thread_data[thread_index].out2in, &kv0,
 135                               &value0))
 136     {
 137       /* or is static mappings */
 138       if (!snat_static_mapping_match (sm, key0, &sm0, 1, 0, 0, 0, 0, 0))
 139         return 0;
 140     }
 141   else
 142     return 0;
 143
 144   if (sm->forwarding_enabled)
 145     return 1;
 146
 147   return snat_not_translate_fast (sm, node, sw_if_index0, ip0, proto0,
 148                                   rx_fib_index0);
 149 }
 150
 151 static inline int
 152 nat_not_translate_output_feature (snat_main_t * sm, ip4_header_t * ip0,
 153                                   u32 proto0, u16 src_port, u16 dst_port,
 154                                   u32 thread_index, u32 sw_if_index)
 155 {
 156   snat_session_key_t key0;
 157   clib_bihash_kv_8_8_t kv0, value0;
 158   snat_interface_t *i;
 159
 160   /* src NAT check */
 161   key0.addr = ip0->src_address;
 162   key0.port = src_port;
 163   key0.protocol = proto0;
 164   key0.fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 165   kv0.key = key0.as_u64;
 166
 167   if (!clib_bihash_search_8_8
 168       (&sm->per_thread_data[thread_index].out2in, &kv0, &value0))
 169     return 1;
 170
 171   /* dst NAT check */
 172   key0.addr = ip0->dst_address;
 173   key0.port = dst_port;
 174   key0.protocol = proto0;
 175   kv0.key = key0.as_u64;
 176   if (!clib_bihash_search_8_8
 177       (&sm->per_thread_data[thread_index].in2out, &kv0, &value0))
 178     {
 179       /* hairpinning */
 180     /* *INDENT-OFF* */
 181     pool_foreach (i, sm->output_feature_interfaces,
 182     ({
 183       if ((nat_interface_is_inside(i)) && (sw_if_index == i->sw_if_index))
 184         return 0;
 185     }));
 186     /* *INDENT-ON* */
 187       return 1;
 188     }
 189
 190   return 0;
 191 }
 192
 193 #ifndef CLIB_MARCH_VARIANT
 194 int
 195 nat44_i2o_is_idle_session_cb (clib_bihash_kv_8_8_t * kv, void *arg)
 196 {
 197   snat_main_t *sm = &snat_main;
 198   nat44_is_idle_session_ctx_t *ctx = arg;
 199   snat_session_t *s;
 200   u64 sess_timeout_time;
 201   snat_main_per_thread_data_t *tsm = vec_elt_at_index (sm->per_thread_data,
 202                                                        ctx->thread_index);
 203   clib_bihash_kv_8_8_t s_kv;
 204
 205   s = pool_elt_at_index (tsm->sessions, kv->value);
 206   sess_timeout_time = s->last_heard + (f64) nat44_session_get_timeout (sm, s);
 207   if (ctx->now >= sess_timeout_time)
 208     {
 209       s_kv.key = s->out2in.as_u64;
 210       if (clib_bihash_add_del_8_8 (&tsm->out2in, &s_kv, 0))
 211         nat_elog_warn ("out2in key del failed");
 212
 213       snat_ipfix_logging_nat44_ses_delete (ctx->thread_index,
 214                                            s->in2out.addr.as_u32,
 215                                            s->out2in.addr.as_u32,
 216                                            s->in2out.protocol,
 217                                            s->in2out.port,
 218                                            s->out2in.port,
 219                                            s->in2out.fib_index);
 220
 221       nat_syslog_nat44_apmdel (s->user_index, s->in2out.fib_index,
 222                                &s->in2out.addr, s->in2out.port,
 223                                &s->out2in.addr, s->out2in.port,
 224                                s->in2out.protocol);
 225
 226       nat_ha_sdel (&s->out2in.addr, s->out2in.port, &s->ext_host_addr,
 227                    s->ext_host_port, s->out2in.protocol, s->out2in.fib_index,
 228                    ctx->thread_index);
 229
 230       if (!snat_is_session_static (s))
 231         snat_free_outside_address_and_port (sm->addresses, ctx->thread_index,
 232                                             &s->out2in);
 233
 234       nat44_delete_session (sm, s, ctx->thread_index);
 235       return 1;
 236     }
 237
 238   return 0;
 239 }
 240 #endif
 241
 242 static u32
 243 slow_path (snat_main_t * sm, vlib_buffer_t * b0,
 244            ip4_header_t * ip0,
 245            u32 rx_fib_index0,
 246            snat_session_key_t * key0,
 247            snat_session_t ** sessionp,
 248            vlib_node_runtime_t * node, u32 next0, u32 thread_index, f64 now)
 249 {
 250   snat_user_t *u;
 251   snat_session_t *s = 0;
 252   clib_bihash_kv_8_8_t kv0;
 253   snat_session_key_t key1;
 254   u8 is_sm = 0;
 255   nat_outside_fib_t *outside_fib;
 256   fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
 257   u8 identity_nat;
 258   fib_prefix_t pfx = {
 259     .fp_proto = FIB_PROTOCOL_IP4,
 260     .fp_len = 32,
 261     .fp_addr = {
 262                 .ip4.as_u32 = ip0->dst_address.as_u32,
 263                 },
 264   };
 265   nat44_is_idle_session_ctx_t ctx0;
 266
 267   if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
 268     {
 269       b0->error = node->errors[SNAT_IN2OUT_ERROR_MAX_SESSIONS_EXCEEDED];
 270       nat_ipfix_logging_max_sessions (thread_index, sm->max_translations);
 271       nat_elog_notice ("maximum sessions exceeded");
 272       return SNAT_IN2OUT_NEXT_DROP;
 273     }
 274
 275   key1.protocol = key0->protocol;
 276
 277   /* First try to match static mapping by local address and port */
 278   if (snat_static_mapping_match
 279       (sm, *key0, &key1, 0, 0, 0, 0, 0, &identity_nat))
 280     {
 281       /* Try to create dynamic translation */
 282       if (snat_alloc_outside_address_and_port (sm->addresses, rx_fib_index0,
 283                                                thread_index, &key1,
 284                                                sm->port_per_thread,
 285                                                sm->per_thread_data
 286                                                [thread_index].snat_thread_index))
 287         {
 288           b0->error = node->errors[SNAT_IN2OUT_ERROR_OUT_OF_PORTS];
 289           return SNAT_IN2OUT_NEXT_DROP;
 290         }
 291     }
 292   else
 293     {
 294       if (PREDICT_FALSE (identity_nat))
 295         {
 296           *sessionp = s;
 297           return next0;
 298         }
 299
 300       is_sm = 1;
 301     }
 302
 303   u = nat_user_get_or_create (sm, &ip0->src_address, rx_fib_index0,
 304                               thread_index);
 305   if (!u)
 306     {
 307       nat_elog_warn ("create NAT user failed");
 308       return SNAT_IN2OUT_NEXT_DROP;
 309     }
 310
 311   s = nat_session_alloc_or_recycle (sm, u, thread_index, now);
 312   if (!s)
 313     {
 314       nat44_delete_user_with_no_session (sm, u, thread_index);
 315       nat_elog_warn ("create NAT session failed");
 316       return SNAT_IN2OUT_NEXT_DROP;
 317     }
 318
 319   if (is_sm)
 320     s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 321   user_session_increment (sm, u, is_sm);
 322   s->in2out = *key0;
 323   s->out2in = key1;
 324   s->out2in.protocol = key0->protocol;
 325   s->out2in.fib_index = sm->outside_fib_index;
 326   switch (vec_len (sm->outside_fibs))
 327     {
 328     case 0:
 329       s->out2in.fib_index = sm->outside_fib_index;
 330       break;
 331     case 1:
 332       s->out2in.fib_index = sm->outside_fibs[0].fib_index;
 333       break;
 334     default:
 335       /* *INDENT-OFF* */
 336       vec_foreach (outside_fib, sm->outside_fibs)
 337         {
 338           fei = fib_table_lookup (outside_fib->fib_index, &pfx);
 339           if (FIB_NODE_INDEX_INVALID != fei)
 340             {
 341               if (fib_entry_get_resolving_interface (fei) != ~0)
 342                 {
 343                   s->out2in.fib_index = outside_fib->fib_index;
 344                   break;
 345                 }
 346             }
 347         }
 348       /* *INDENT-ON* */
 349       break;
 350     }
 351   s->ext_host_addr.as_u32 = ip0->dst_address.as_u32;
 352   s->ext_host_port = vnet_buffer (b0)->ip.reass.l4_dst_port;
 353   *sessionp = s;
 354
 355   /* Add to translation hashes */
 356   ctx0.now = now;
 357   ctx0.thread_index = thread_index;
 358   kv0.key = s->in2out.as_u64;
 359   kv0.value = s - sm->per_thread_data[thread_index].sessions;
 360   if (clib_bihash_add_or_overwrite_stale_8_8
 361       (&sm->per_thread_data[thread_index].in2out, &kv0,
 362        nat44_i2o_is_idle_session_cb, &ctx0))
 363     nat_elog_notice ("in2out key add failed");
 364
 365   kv0.key = s->out2in.as_u64;
 366   kv0.value = s - sm->per_thread_data[thread_index].sessions;
 367
 368   if (clib_bihash_add_or_overwrite_stale_8_8
 369       (&sm->per_thread_data[thread_index].out2in, &kv0,
 370        nat44_o2i_is_idle_session_cb, &ctx0))
 371     nat_elog_notice ("out2in key add failed");
 372
 373   /* log NAT event */
 374   snat_ipfix_logging_nat44_ses_create (thread_index,
 375                                        s->in2out.addr.as_u32,
 376                                        s->out2in.addr.as_u32,
 377                                        s->in2out.protocol,
 378                                        s->in2out.port,
 379                                        s->out2in.port, s->in2out.fib_index);
 380
 381   nat_syslog_nat44_apmadd (s->user_index, s->in2out.fib_index,
 382                            &s->in2out.addr, s->in2out.port, &s->out2in.addr,
 383                            s->out2in.port, s->in2out.protocol);
 384
 385   nat_ha_sadd (&s->in2out.addr, s->in2out.port, &s->out2in.addr,
 386                s->out2in.port, &s->ext_host_addr, s->ext_host_port,
 387                &s->ext_host_nat_addr, s->ext_host_nat_port,
 388                s->in2out.protocol, s->in2out.fib_index, s->flags,
 389                thread_index, 0);
 390
 391   return next0;
 392 }
 393
 394 #ifndef CLIB_MARCH_VARIANT
 395 static_always_inline
 396   snat_in2out_error_t icmp_get_key (vlib_buffer_t * b, ip4_header_t * ip0,
 397                                     snat_session_key_t * p_key0)
 398 {
 399   icmp46_header_t *icmp0;
 400   snat_session_key_t key0;
 401   icmp_echo_header_t *echo0, *inner_echo0 = 0;
 402   ip4_header_t *inner_ip0 = 0;
 403   void *l4_header = 0;
 404   icmp46_header_t *inner_icmp0;
 405
 406   icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
 407   echo0 = (icmp_echo_header_t *) (icmp0 + 1);
 408
 409   if (!icmp_type_is_error_message
 410       (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags))
 411     {
 412       key0.protocol = SNAT_PROTOCOL_ICMP;
 413       key0.addr = ip0->src_address;
 414       key0.port = vnet_buffer (b)->ip.reass.l4_src_port;        // TODO fixme should this be dst port?
 415     }
 416   else
 417     {
 418       inner_ip0 = (ip4_header_t *) (echo0 + 1);
 419       l4_header = ip4_next_header (inner_ip0);
 420       key0.protocol = ip_proto_to_snat_proto (inner_ip0->protocol);
 421       key0.addr = inner_ip0->dst_address;
 422       switch (key0.protocol)
 423         {
 424         case SNAT_PROTOCOL_ICMP:
 425           inner_icmp0 = (icmp46_header_t *) l4_header;
 426           inner_echo0 = (icmp_echo_header_t *) (inner_icmp0 + 1);
 427           key0.port = inner_echo0->identifier;
 428           break;
 429         case SNAT_PROTOCOL_UDP:
 430         case SNAT_PROTOCOL_TCP:
 431           key0.port = ((tcp_udp_header_t *) l4_header)->dst_port;
 432           break;
 433         default:
 434           return SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL;
 435         }
 436     }
 437   *p_key0 = key0;
 438   return -1;                    /* success */
 439 }
 440
 441 /**
 442  * Get address and port values to be used for ICMP packet translation
 443  * and create session if needed
 444  *
 445  * @param[in,out] sm             NAT main
 446  * @param[in,out] node           NAT node runtime
 447  * @param[in] thread_index       thread index
 448  * @param[in,out] b0             buffer containing packet to be translated
 449  * @param[in,out] ip0            ip header
 450  * @param[out] p_proto           protocol used for matching
 451  * @param[out] p_value           address and port after NAT translation
 452  * @param[out] p_dont_translate  if packet should not be translated
 453  * @param d                      optional parameter
 454  * @param e                      optional parameter
 455  */
 456 u32
 457 icmp_match_in2out_slow (snat_main_t * sm, vlib_node_runtime_t * node,
 458                         u32 thread_index, vlib_buffer_t * b0,
 459                         ip4_header_t * ip0, u8 * p_proto,
 460                         snat_session_key_t * p_value,
 461                         u8 * p_dont_translate, void *d, void *e)
 462 {
 463   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 464   u32 sw_if_index0;
 465   u32 rx_fib_index0;
 466   snat_session_key_t key0;
 467   snat_session_t *s0 = 0;
 468   u8 dont_translate = 0;
 469   clib_bihash_kv_8_8_t kv0, value0;
 470   u32 next0 = ~0;
 471   int err;
 472   vlib_main_t *vm = vlib_get_main ();
 473
 474   sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 475   rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
 476
 477   err = icmp_get_key (b0, ip0, &key0);
 478   if (err != -1)
 479     {
 480       b0->error = node->errors[err];
 481       next0 = SNAT_IN2OUT_NEXT_DROP;
 482       goto out;
 483     }
 484   key0.fib_index = rx_fib_index0;
 485
 486   kv0.key = key0.as_u64;
 487
 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 (nat_not_translate_output_feature (sm, ip0,
 493                                                                key0.protocol,
 494                                                                key0.port,
 495                                                                key0.port,
 496                                                                thread_index,
 497                                                                sw_if_index0)))
 498             {
 499               dont_translate = 1;
 500               goto out;
 501             }
 502         }
 503       else
 504         {
 505           if (PREDICT_FALSE (snat_not_translate (sm, node, sw_if_index0,
 506                                                  ip0, SNAT_PROTOCOL_ICMP,
 507                                                  rx_fib_index0,
 508                                                  thread_index)))
 509             {
 510               dont_translate = 1;
 511               goto out;
 512             }
 513         }
 514
 515       if (PREDICT_FALSE
 516           (icmp_type_is_error_message
 517            (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags)))
 518         {
 519           b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
 520           next0 = SNAT_IN2OUT_NEXT_DROP;
 521           goto out;
 522         }
 523
 524       next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0, &s0, node, next0,
 525                          thread_index, vlib_time_now (vm));
 526
 527       if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
 528         goto out;
 529
 530       if (!s0)
 531         {
 532           dont_translate = 1;
 533           goto out;
 534         }
 535     }
 536   else
 537     {
 538       if (PREDICT_FALSE
 539           (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
 540            ICMP4_echo_request
 541            && vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
 542            ICMP4_echo_reply
 543            && !icmp_type_is_error_message (vnet_buffer (b0)->ip.
 544                                            reass.icmp_type_or_tcp_flags)))
 545         {
 546           b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
 547           next0 = SNAT_IN2OUT_NEXT_DROP;
 548           goto out;
 549         }
 550
 551       s0 = pool_elt_at_index (tsm->sessions, value0.value);
 552     }
 553
 554 out:
 555   *p_proto = key0.protocol;
 556   if (s0)
 557     *p_value = s0->out2in;
 558   *p_dont_translate = dont_translate;
 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, u8 * p_proto,
 584                         snat_session_key_t * p_value,
 585                         u8 * p_dont_translate, void *d, void *e)
 586 {
 587   u32 sw_if_index0;
 588   u32 rx_fib_index0;
 589   snat_session_key_t key0;
 590   snat_session_key_t sm0;
 591   u8 dont_translate = 0;
 592   u8 is_addr_only;
 593   u32 next0 = ~0;
 594   int err;
 595
 596   sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 597   rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
 598
 599   err = icmp_get_key (b0, ip0, &key0);
 600   if (err != -1)
 601     {
 602       b0->error = node->errors[err];
 603       next0 = SNAT_IN2OUT_NEXT_DROP;
 604       goto out2;
 605     }
 606   key0.fib_index = rx_fib_index0;
 607
 608   if (snat_static_mapping_match
 609       (sm, key0, &sm0, 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                                                   rx_fib_index0)))
 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   *p_value = sm0;
 645 out2:
 646   *p_proto = key0.protocol;
 647   *p_dont_translate = dont_translate;
 648   return next0;
 649 }
 650 #endif
 651
 652 #ifndef CLIB_MARCH_VARIANT
 653 u32
 654 icmp_in2out (snat_main_t * sm,
 655              vlib_buffer_t * b0,
 656              ip4_header_t * ip0,
 657              icmp46_header_t * icmp0,
 658              u32 sw_if_index0,
 659              u32 rx_fib_index0,
 660              vlib_node_runtime_t * node,
 661              u32 next0, u32 thread_index, void *d, void *e)
 662 {
 663   vlib_main_t *vm = vlib_get_main ();
 664   snat_session_key_t sm0;
 665   u8 protocol;
 666   icmp_echo_header_t *echo0, *inner_echo0 = 0;
 667   ip4_header_t *inner_ip0;
 668   void *l4_header = 0;
 669   icmp46_header_t *inner_icmp0;
 670   u8 dont_translate;
 671   u32 new_addr0, old_addr0;
 672   u16 old_id0, new_id0;
 673   u16 old_checksum0, new_checksum0;
 674   ip_csum_t sum0;
 675   u16 checksum0;
 676   u32 next0_tmp;
 677
 678   echo0 = (icmp_echo_header_t *) (icmp0 + 1);
 679
 680   next0_tmp = sm->icmp_match_in2out_cb (sm, node, thread_index, b0, ip0,
 681                                         &protocol, &sm0, &dont_translate, d,
 682                                         e);
 683   if (next0_tmp != ~0)
 684     next0 = next0_tmp;
 685   if (next0 == SNAT_IN2OUT_NEXT_DROP || dont_translate)
 686     goto out;
 687
 688   if (PREDICT_TRUE (!ip4_is_fragment (ip0)))
 689     {
 690       sum0 =
 691         ip_incremental_checksum_buffer (vm, b0,
 692                                         (u8 *) icmp0 -
 693                                         (u8 *) vlib_buffer_get_current (b0),
 694                                         ntohs (ip0->length) -
 695                                         ip4_header_bytes (ip0), 0);
 696       checksum0 = ~ip_csum_fold (sum0);
 697       if (PREDICT_FALSE (checksum0 != 0 && checksum0 != 0xffff))
 698         {
 699           next0 = SNAT_IN2OUT_NEXT_DROP;
 700           goto out;
 701         }
 702     }
 703
 704   old_addr0 = ip0->src_address.as_u32;
 705   new_addr0 = ip0->src_address.as_u32 = sm0.addr.as_u32;
 706
 707   sum0 = ip0->checksum;
 708   sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 709                          src_address /* changed member */ );
 710   ip0->checksum = ip_csum_fold (sum0);
 711
 712   if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
 713     {
 714       if (icmp0->checksum == 0)
 715         icmp0->checksum = 0xffff;
 716
 717       if (!icmp_type_is_error_message (icmp0->type))
 718         {
 719           new_id0 = sm0.port;
 720           if (PREDICT_FALSE (new_id0 != echo0->identifier))
 721             {
 722               old_id0 = echo0->identifier;
 723               new_id0 = sm0.port;
 724               echo0->identifier = new_id0;
 725
 726               sum0 = icmp0->checksum;
 727               sum0 =
 728                 ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
 729                                 identifier);
 730               icmp0->checksum = ip_csum_fold (sum0);
 731             }
 732         }
 733       else
 734         {
 735           inner_ip0 = (ip4_header_t *) (echo0 + 1);
 736           l4_header = ip4_next_header (inner_ip0);
 737
 738           if (!ip4_header_checksum_is_valid (inner_ip0))
 739             {
 740               next0 = SNAT_IN2OUT_NEXT_DROP;
 741               goto out;
 742             }
 743
 744           /* update inner destination IP address */
 745           old_addr0 = inner_ip0->dst_address.as_u32;
 746           inner_ip0->dst_address = sm0.addr;
 747           new_addr0 = inner_ip0->dst_address.as_u32;
 748           sum0 = icmp0->checksum;
 749           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 750                                  dst_address /* changed member */ );
 751           icmp0->checksum = ip_csum_fold (sum0);
 752
 753           /* update inner IP header checksum */
 754           old_checksum0 = inner_ip0->checksum;
 755           sum0 = inner_ip0->checksum;
 756           sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 757                                  dst_address /* changed member */ );
 758           inner_ip0->checksum = ip_csum_fold (sum0);
 759           new_checksum0 = inner_ip0->checksum;
 760           sum0 = icmp0->checksum;
 761           sum0 =
 762             ip_csum_update (sum0, old_checksum0, new_checksum0, ip4_header_t,
 763                             checksum);
 764           icmp0->checksum = ip_csum_fold (sum0);
 765
 766           switch (protocol)
 767             {
 768             case SNAT_PROTOCOL_ICMP:
 769               inner_icmp0 = (icmp46_header_t *) l4_header;
 770               inner_echo0 = (icmp_echo_header_t *) (inner_icmp0 + 1);
 771
 772               old_id0 = inner_echo0->identifier;
 773               new_id0 = sm0.port;
 774               inner_echo0->identifier = new_id0;
 775
 776               sum0 = icmp0->checksum;
 777               sum0 =
 778                 ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
 779                                 identifier);
 780               icmp0->checksum = ip_csum_fold (sum0);
 781               break;
 782             case SNAT_PROTOCOL_UDP:
 783             case SNAT_PROTOCOL_TCP:
 784               old_id0 = ((tcp_udp_header_t *) l4_header)->dst_port;
 785               new_id0 = sm0.port;
 786               ((tcp_udp_header_t *) l4_header)->dst_port = new_id0;
 787
 788               sum0 = icmp0->checksum;
 789               sum0 = ip_csum_update (sum0, old_id0, new_id0, tcp_udp_header_t,
 790                                      dst_port);
 791               icmp0->checksum = ip_csum_fold (sum0);
 792               break;
 793             default:
 794               ASSERT (0);
 795             }
 796         }
 797     }
 798
 799   if (vnet_buffer (b0)->sw_if_index[VLIB_TX] == ~0)
 800     {
 801       if (sm->deterministic ||
 802           0 != snat_icmp_hairpinning (sm, b0, ip0, icmp0,
 803                                       sm->endpoint_dependent))
 804         vnet_buffer (b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
 805     }
 806
 807 out:
 808   return next0;
 809 }
 810 #endif
 811
 812 static inline u32
 813 icmp_in2out_slow_path (snat_main_t * sm,
 814                        vlib_buffer_t * b0,
 815                        ip4_header_t * ip0,
 816                        icmp46_header_t * icmp0,
 817                        u32 sw_if_index0,
 818                        u32 rx_fib_index0,
 819                        vlib_node_runtime_t * node,
 820                        u32 next0,
 821                        f64 now, u32 thread_index, snat_session_t ** p_s0)
 822 {
 823   vlib_main_t *vm = vlib_get_main ();
 824
 825   next0 = icmp_in2out (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
 826                        next0, thread_index, p_s0, 0);
 827   snat_session_t *s0 = *p_s0;
 828   if (PREDICT_TRUE (next0 != SNAT_IN2OUT_NEXT_DROP && s0))
 829     {
 830       /* Accounting */
 831       nat44_session_update_counters (s0, now,
 832                                      vlib_buffer_length_in_chain
 833                                      (vm, b0), thread_index);
 834       /* Per-user LRU list maintenance */
 835       nat44_session_update_lru (sm, s0, thread_index);
 836     }
 837   return next0;
 838 }
 839
 840 static int
 841 nat_in2out_sm_unknown_proto (snat_main_t * sm,
 842                              vlib_buffer_t * b,
 843                              ip4_header_t * ip, u32 rx_fib_index)
 844 {
 845   clib_bihash_kv_8_8_t kv, value;
 846   snat_static_mapping_t *m;
 847   snat_session_key_t m_key;
 848   u32 old_addr, new_addr;
 849   ip_csum_t sum;
 850
 851   m_key.addr = ip->src_address;
 852   m_key.port = 0;
 853   m_key.protocol = 0;
 854   m_key.fib_index = rx_fib_index;
 855   kv.key = m_key.as_u64;
 856   if (clib_bihash_search_8_8 (&sm->static_mapping_by_local, &kv, &value))
 857     return 1;
 858
 859   m = pool_elt_at_index (sm->static_mappings, value.value);
 860
 861   old_addr = ip->src_address.as_u32;
 862   new_addr = ip->src_address.as_u32 = m->external_addr.as_u32;
 863   sum = ip->checksum;
 864   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, src_address);
 865   ip->checksum = ip_csum_fold (sum);
 866
 867
 868   /* Hairpinning */
 869   if (vnet_buffer (b)->sw_if_index[VLIB_TX] == ~0)
 870     {
 871       vnet_buffer (b)->sw_if_index[VLIB_TX] = m->fib_index;
 872       nat_hairpinning_sm_unknown_proto (sm, b, ip);
 873     }
 874
 875   return 0;
 876 }
 877
 878 static inline uword
 879 snat_in2out_node_fn_inline (vlib_main_t * vm,
 880                             vlib_node_runtime_t * node,
 881                             vlib_frame_t * frame, int is_slow_path,
 882                             int is_output_feature)
 883 {
 884   u32 n_left_from, *from, *to_next;
 885   snat_in2out_next_t next_index;
 886   u32 pkts_processed = 0;
 887   snat_main_t *sm = &snat_main;
 888   f64 now = vlib_time_now (vm);
 889   u32 stats_node_index;
 890   u32 thread_index = vm->thread_index;
 891   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 892     0, fragments = 0;
 893
 894   stats_node_index = is_slow_path ? sm->in2out_slowpath_node_index :
 895     sm->in2out_node_index;
 896
 897   from = vlib_frame_vector_args (frame);
 898   n_left_from = frame->n_vectors;
 899   next_index = node->cached_next_index;
 900
 901   while (n_left_from > 0)
 902     {
 903       u32 n_left_to_next;
 904
 905       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 906
 907       while (n_left_from >= 4 && n_left_to_next >= 2)
 908         {
 909           u32 bi0, bi1;
 910           vlib_buffer_t *b0, *b1;
 911           u32 next0, next1;
 912           u32 sw_if_index0, sw_if_index1;
 913           ip4_header_t *ip0, *ip1;
 914           ip_csum_t sum0, sum1;
 915           u32 new_addr0, old_addr0, new_addr1, old_addr1;
 916           u16 old_port0, new_port0, old_port1, new_port1;
 917           udp_header_t *udp0, *udp1;
 918           tcp_header_t *tcp0, *tcp1;
 919           icmp46_header_t *icmp0, *icmp1;
 920           snat_session_key_t key0, key1;
 921           u32 rx_fib_index0, rx_fib_index1;
 922           u32 proto0, proto1;
 923           snat_session_t *s0 = 0, *s1 = 0;
 924           clib_bihash_kv_8_8_t kv0, value0, kv1, value1;
 925           u32 iph_offset0 = 0, iph_offset1 = 0;
 926
 927           /* Prefetch next iteration. */
 928           {
 929             vlib_buffer_t *p2, *p3;
 930
 931             p2 = vlib_get_buffer (vm, from[2]);
 932             p3 = vlib_get_buffer (vm, from[3]);
 933
 934             vlib_prefetch_buffer_header (p2, LOAD);
 935             vlib_prefetch_buffer_header (p3, LOAD);
 936
 937             CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE);
 938             CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE);
 939           }
 940
 941           /* speculatively enqueue b0 and b1 to the current next frame */
 942           to_next[0] = bi0 = from[0];
 943           to_next[1] = bi1 = from[1];
 944           from += 2;
 945           to_next += 2;
 946           n_left_from -= 2;
 947           n_left_to_next -= 2;
 948
 949           b0 = vlib_get_buffer (vm, bi0);
 950           b1 = vlib_get_buffer (vm, bi1);
 951
 952           if (is_output_feature)
 953             iph_offset0 = vnet_buffer (b0)->ip.reass.save_rewrite_length;
 954
 955           ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
 956                                   iph_offset0);
 957
 958           udp0 = ip4_next_header (ip0);
 959           tcp0 = (tcp_header_t *) udp0;
 960           icmp0 = (icmp46_header_t *) udp0;
 961
 962           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 963           rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
 964                                    sw_if_index0);
 965
 966           next0 = next1 = SNAT_IN2OUT_NEXT_LOOKUP;
 967
 968           if (PREDICT_FALSE (ip0->ttl == 1))
 969             {
 970               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 971               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 972                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 973                                            0);
 974               next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
 975               goto trace00;
 976             }
 977
 978           proto0 = ip_proto_to_snat_proto (ip0->protocol);
 979
 980           /* Next configured feature, probably ip4-lookup */
 981           if (is_slow_path)
 982             {
 983               if (PREDICT_FALSE (proto0 == ~0))
 984                 {
 985                   if (nat_in2out_sm_unknown_proto
 986                       (sm, b0, ip0, rx_fib_index0))
 987                     {
 988                       next0 = SNAT_IN2OUT_NEXT_DROP;
 989                       b0->error =
 990                         node->errors[SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL];
 991                     }
 992                   other_packets++;
 993                   goto trace00;
 994                 }
 995
 996               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
 997                 {
 998                   next0 = icmp_in2out_slow_path
 999                     (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0,
1000                      node, next0, now, thread_index, &s0);
1001                   icmp_packets++;
1002                   goto trace00;
1003                 }
1004             }
1005           else
1006             {
1007               if (PREDICT_FALSE (proto0 == ~0))
1008                 {
1009                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1010                   goto trace00;
1011                 }
1012
1013               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1014                 {
1015                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1016                   goto trace00;
1017                 }
1018             }
1019
1020           key0.addr = ip0->src_address;
1021           key0.port = vnet_buffer (b0)->ip.reass.l4_src_port;
1022           key0.protocol = proto0;
1023           key0.fib_index = rx_fib_index0;
1024
1025           kv0.key = key0.as_u64;
1026
1027           if (PREDICT_FALSE
1028               (clib_bihash_search_8_8
1029                (&sm->per_thread_data[thread_index].in2out, &kv0,
1030                 &value0) != 0))
1031             {
1032               if (is_slow_path)
1033                 {
1034                   if (is_output_feature)
1035                     {
1036                       if (PREDICT_FALSE
1037                           (nat_not_translate_output_feature
1038                            (sm, ip0, proto0,
1039                             vnet_buffer (b0)->ip.reass.l4_src_port,
1040                             vnet_buffer (b0)->ip.reass.l4_dst_port,
1041                             thread_index, sw_if_index0)))
1042                         goto trace00;
1043
1044                       /*
1045                        * Send DHCP packets to the ipv4 stack, or we won't
1046                        * be able to use dhcp client on the outside interface
1047                        */
1048                       if (PREDICT_FALSE
1049                           (proto0 == SNAT_PROTOCOL_UDP
1050                            && (vnet_buffer (b0)->ip.reass.l4_dst_port ==
1051                                clib_host_to_net_u16
1052                                (UDP_DST_PORT_dhcp_to_server))
1053                            && ip0->dst_address.as_u32 == 0xffffffff))
1054                         goto trace00;
1055                     }
1056                   else
1057                     {
1058                       if (PREDICT_FALSE
1059                           (snat_not_translate
1060                            (sm, node, sw_if_index0, ip0, proto0,
1061                             rx_fib_index0, thread_index)))
1062                         goto trace00;
1063                     }
1064
1065                   next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0,
1066                                      &s0, node, next0, thread_index, now);
1067                   if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
1068                     goto trace00;
1069
1070                   if (PREDICT_FALSE (!s0))
1071                     goto trace00;
1072                 }
1073               else
1074                 {
1075                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1076                   goto trace00;
1077                 }
1078             }
1079           else
1080             s0 =
1081               pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
1082                                  value0.value);
1083
1084           b0->flags |= VNET_BUFFER_F_IS_NATED;
1085
1086           old_addr0 = ip0->src_address.as_u32;
1087           ip0->src_address = s0->out2in.addr;
1088           new_addr0 = ip0->src_address.as_u32;
1089           if (!is_output_feature)
1090             vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
1091
1092           sum0 = ip0->checksum;
1093           sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1094                                  ip4_header_t,
1095                                  src_address /* changed member */ );
1096           ip0->checksum = ip_csum_fold (sum0);
1097
1098
1099           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
1100             {
1101               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1102                 {
1103                   old_port0 = vnet_buffer (b0)->ip.reass.l4_src_port;
1104                   new_port0 = udp0->src_port = s0->out2in.port;
1105                   sum0 = tcp0->checksum;
1106                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1107                                          ip4_header_t,
1108                                          dst_address /* changed member */ );
1109                   sum0 = ip_csum_update (sum0, old_port0, new_port0,
1110                                          ip4_header_t /* cheat */ ,
1111                                          length /* changed member */ );
1112                   mss_clamping (sm, tcp0, &sum0);
1113                   tcp0->checksum = ip_csum_fold (sum0);
1114                 }
1115               tcp_packets++;
1116             }
1117           else
1118             {
1119               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1120                 {
1121                   if (PREDICT_FALSE (udp0->checksum))
1122                     {
1123                       old_port0 = vnet_buffer (b0)->ip.reass.l4_src_port;
1124                       new_port0 = udp0->src_port = s0->out2in.port;
1125                       sum0 = udp0->checksum;
1126                       sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t, dst_address      /* changed member */
1127                         );
1128                       sum0 =
1129                         ip_csum_update (sum0, old_port0, new_port0,
1130                                         ip4_header_t /* cheat */ ,
1131                                         length /* changed member */ );
1132                       udp0->checksum = ip_csum_fold (sum0);
1133                     }
1134                 }
1135               udp_packets++;
1136             }
1137
1138           /* Accounting */
1139           nat44_session_update_counters (s0, now,
1140                                          vlib_buffer_length_in_chain (vm, b0),
1141                                          thread_index);
1142           /* Per-user LRU list maintenance */
1143           nat44_session_update_lru (sm, s0, thread_index);
1144         trace00:
1145
1146           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1147                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1148             {
1149               snat_in2out_trace_t *t =
1150                 vlib_add_trace (vm, node, b0, sizeof (*t));
1151               t->is_slow_path = is_slow_path;
1152               t->sw_if_index = sw_if_index0;
1153               t->next_index = next0;
1154               t->session_index = ~0;
1155               if (s0)
1156                 t->session_index =
1157                   s0 - sm->per_thread_data[thread_index].sessions;
1158             }
1159
1160           pkts_processed += next0 == SNAT_IN2OUT_NEXT_LOOKUP;
1161
1162           if (is_output_feature)
1163             iph_offset1 = vnet_buffer (b1)->ip.reass.save_rewrite_length;
1164
1165           ip1 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b1) +
1166                                   iph_offset1);
1167
1168           udp1 = ip4_next_header (ip1);
1169           tcp1 = (tcp_header_t *) udp1;
1170           icmp1 = (icmp46_header_t *) udp1;
1171
1172           sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];
1173           rx_fib_index1 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
1174                                    sw_if_index1);
1175
1176           if (PREDICT_FALSE (ip1->ttl == 1))
1177             {
1178               vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1179               icmp4_error_set_vnet_buffer (b1, ICMP4_time_exceeded,
1180                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1181                                            0);
1182               next1 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
1183               goto trace01;
1184             }
1185
1186           proto1 = ip_proto_to_snat_proto (ip1->protocol);
1187
1188           /* Next configured feature, probably ip4-lookup */
1189           if (is_slow_path)
1190             {
1191               if (PREDICT_FALSE (proto1 == ~0))
1192                 {
1193                   if (nat_in2out_sm_unknown_proto
1194                       (sm, b1, ip1, rx_fib_index1))
1195                     {
1196                       next1 = SNAT_IN2OUT_NEXT_DROP;
1197                       b1->error =
1198                         node->errors[SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL];
1199                     }
1200                   other_packets++;
1201                   goto trace01;
1202                 }
1203
1204               if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP))
1205                 {
1206                   next1 = icmp_in2out_slow_path
1207                     (sm, b1, ip1, icmp1, sw_if_index1, rx_fib_index1, node,
1208                      next1, now, thread_index, &s1);
1209                   icmp_packets++;
1210                   goto trace01;
1211                 }
1212             }
1213           else
1214             {
1215               if (PREDICT_FALSE (proto1 == ~0))
1216                 {
1217                   next1 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1218                   goto trace01;
1219                 }
1220
1221               if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP))
1222                 {
1223                   next1 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1224                   goto trace01;
1225                 }
1226             }
1227
1228           key1.addr = ip1->src_address;
1229           key1.port = vnet_buffer (b1)->ip.reass.l4_src_port;
1230           key1.protocol = proto1;
1231           key1.fib_index = rx_fib_index1;
1232
1233           kv1.key = key1.as_u64;
1234
1235           if (PREDICT_FALSE
1236               (clib_bihash_search_8_8
1237                (&sm->per_thread_data[thread_index].in2out, &kv1,
1238                 &value1) != 0))
1239             {
1240               if (is_slow_path)
1241                 {
1242                   if (is_output_feature)
1243                     {
1244                       if (PREDICT_FALSE
1245                           (nat_not_translate_output_feature
1246                            (sm, ip1, proto1,
1247                             vnet_buffer (b1)->ip.reass.l4_src_port,
1248                             vnet_buffer (b1)->ip.reass.l4_dst_port,
1249                             thread_index, sw_if_index1)))
1250                         goto trace01;
1251
1252                       /*
1253                        * Send DHCP packets to the ipv4 stack, or we won't
1254                        * be able to use dhcp client on the outside interface
1255                        */
1256                       if (PREDICT_FALSE
1257                           (proto1 == SNAT_PROTOCOL_UDP
1258                            && (vnet_buffer (b1)->ip.reass.l4_dst_port ==
1259                                clib_host_to_net_u16
1260                                (UDP_DST_PORT_dhcp_to_server))
1261                            && ip1->dst_address.as_u32 == 0xffffffff))
1262                         goto trace01;
1263                     }
1264                   else
1265                     {
1266                       if (PREDICT_FALSE
1267                           (snat_not_translate
1268                            (sm, node, sw_if_index1, ip1, proto1,
1269                             rx_fib_index1, thread_index)))
1270                         goto trace01;
1271                     }
1272
1273                   next1 = slow_path (sm, b1, ip1, rx_fib_index1, &key1,
1274                                      &s1, node, next1, thread_index, now);
1275                   if (PREDICT_FALSE (next1 == SNAT_IN2OUT_NEXT_DROP))
1276                     goto trace01;
1277
1278                   if (PREDICT_FALSE (!s1))
1279                     goto trace01;
1280                 }
1281               else
1282                 {
1283                   next1 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1284                   goto trace01;
1285                 }
1286             }
1287           else
1288             s1 =
1289               pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
1290                                  value1.value);
1291
1292           b1->flags |= VNET_BUFFER_F_IS_NATED;
1293
1294           old_addr1 = ip1->src_address.as_u32;
1295           ip1->src_address = s1->out2in.addr;
1296           new_addr1 = ip1->src_address.as_u32;
1297           if (!is_output_feature)
1298             vnet_buffer (b1)->sw_if_index[VLIB_TX] = s1->out2in.fib_index;
1299
1300           sum1 = ip1->checksum;
1301           sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
1302                                  ip4_header_t,
1303                                  src_address /* changed member */ );
1304           ip1->checksum = ip_csum_fold (sum1);
1305
1306           if (PREDICT_TRUE (proto1 == SNAT_PROTOCOL_TCP))
1307             {
1308               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1309                 {
1310                   old_port1 = vnet_buffer (b1)->ip.reass.l4_src_port;
1311                   new_port1 = udp1->src_port = s1->out2in.port;
1312                   sum1 = tcp1->checksum;
1313                   sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
1314                                          ip4_header_t,
1315                                          dst_address /* changed member */ );
1316                   sum1 = ip_csum_update (sum1, old_port1, new_port1,
1317                                          ip4_header_t /* cheat */ ,
1318                                          length /* changed member */ );
1319                   mss_clamping (sm, tcp1, &sum1);
1320                   tcp1->checksum = ip_csum_fold (sum1);
1321                 }
1322               tcp_packets++;
1323             }
1324           else
1325             {
1326               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1327                 {
1328                   if (PREDICT_FALSE (udp1->checksum))
1329                     {
1330                       old_port1 = vnet_buffer (b1)->ip.reass.l4_src_port;
1331                       new_port1 = udp1->src_port = s1->out2in.port;
1332                       sum1 = udp1->checksum;
1333                       sum1 = ip_csum_update (sum1, old_addr1, new_addr1, ip4_header_t, dst_address      /* changed member */
1334                         );
1335                       sum1 =
1336                         ip_csum_update (sum1, old_port1, new_port1,
1337                                         ip4_header_t /* cheat */ ,
1338                                         length /* changed member */ );
1339                       udp1->checksum = ip_csum_fold (sum1);
1340                     }
1341                 }
1342               udp_packets++;
1343             }
1344
1345           /* Accounting */
1346           nat44_session_update_counters (s1, now,
1347                                          vlib_buffer_length_in_chain (vm, b1),
1348                                          thread_index);
1349           /* Per-user LRU list maintenance */
1350           nat44_session_update_lru (sm, s1, thread_index);
1351         trace01:
1352
1353           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1354                              && (b1->flags & VLIB_BUFFER_IS_TRACED)))
1355             {
1356               snat_in2out_trace_t *t =
1357                 vlib_add_trace (vm, node, b1, sizeof (*t));
1358               t->sw_if_index = sw_if_index1;
1359               t->next_index = next1;
1360               t->session_index = ~0;
1361               if (s1)
1362                 t->session_index =
1363                   s1 - sm->per_thread_data[thread_index].sessions;
1364             }
1365
1366           pkts_processed += next1 == SNAT_IN2OUT_NEXT_LOOKUP;
1367
1368           /* verify speculative enqueues, maybe switch current next frame */
1369           vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
1370                                            to_next, n_left_to_next,
1371                                            bi0, bi1, next0, next1);
1372         }
1373
1374       while (n_left_from > 0 && n_left_to_next > 0)
1375         {
1376           u32 bi0;
1377           vlib_buffer_t *b0;
1378           u32 next0;
1379           u32 sw_if_index0;
1380           ip4_header_t *ip0;
1381           ip_csum_t sum0;
1382           u32 new_addr0, old_addr0;
1383           u16 old_port0, new_port0;
1384           udp_header_t *udp0;
1385           tcp_header_t *tcp0;
1386           icmp46_header_t *icmp0;
1387           snat_session_key_t key0;
1388           u32 rx_fib_index0;
1389           u32 proto0;
1390           snat_session_t *s0 = 0;
1391           clib_bihash_kv_8_8_t kv0, value0;
1392           u32 iph_offset0 = 0;
1393
1394           /* speculatively enqueue b0 to the current next frame */
1395           bi0 = from[0];
1396           to_next[0] = bi0;
1397           from += 1;
1398           to_next += 1;
1399           n_left_from -= 1;
1400           n_left_to_next -= 1;
1401
1402           b0 = vlib_get_buffer (vm, bi0);
1403           next0 = SNAT_IN2OUT_NEXT_LOOKUP;
1404
1405           if (is_output_feature)
1406             iph_offset0 = vnet_buffer (b0)->ip.reass.save_rewrite_length;
1407
1408           ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
1409                                   iph_offset0);
1410
1411           udp0 = ip4_next_header (ip0);
1412           tcp0 = (tcp_header_t *) udp0;
1413           icmp0 = (icmp46_header_t *) udp0;
1414
1415           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1416           rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
1417                                    sw_if_index0);
1418
1419           if (PREDICT_FALSE (ip0->ttl == 1))
1420             {
1421               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1422               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1423                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1424                                            0);
1425               next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
1426               goto trace0;
1427             }
1428
1429           proto0 = ip_proto_to_snat_proto (ip0->protocol);
1430
1431           /* Next configured feature, probably ip4-lookup */
1432           if (is_slow_path)
1433             {
1434               if (PREDICT_FALSE (proto0 == ~0))
1435                 {
1436                   if (nat_in2out_sm_unknown_proto
1437                       (sm, b0, ip0, rx_fib_index0))
1438                     {
1439                       next0 = SNAT_IN2OUT_NEXT_DROP;
1440                       b0->error =
1441                         node->errors[SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL];
1442                     }
1443                   other_packets++;
1444                   goto trace0;
1445                 }
1446
1447               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1448                 {
1449                   next0 = icmp_in2out_slow_path
1450                     (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1451                      next0, now, thread_index, &s0);
1452                   icmp_packets++;
1453                   goto trace0;
1454                 }
1455             }
1456           else
1457             {
1458               if (PREDICT_FALSE (proto0 == ~0))
1459                 {
1460                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1461                   goto trace0;
1462                 }
1463
1464               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1465                 {
1466                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1467                   goto trace0;
1468                 }
1469             }
1470
1471           key0.addr = ip0->src_address;
1472           key0.port = vnet_buffer (b0)->ip.reass.l4_src_port;
1473           key0.protocol = proto0;
1474           key0.fib_index = rx_fib_index0;
1475
1476           kv0.key = key0.as_u64;
1477
1478           if (clib_bihash_search_8_8
1479               (&sm->per_thread_data[thread_index].in2out, &kv0, &value0))
1480             {
1481               if (is_slow_path)
1482                 {
1483                   if (is_output_feature)
1484                     {
1485                       if (PREDICT_FALSE
1486                           (nat_not_translate_output_feature
1487                            (sm, ip0, proto0,
1488                             vnet_buffer (b0)->ip.reass.l4_src_port,
1489                             vnet_buffer (b0)->ip.reass.l4_dst_port,
1490                             thread_index, sw_if_index0)))
1491                         goto trace0;
1492
1493                       /*
1494                        * Send DHCP packets to the ipv4 stack, or we won't
1495                        * be able to use dhcp client on the outside interface
1496                        */
1497                       if (PREDICT_FALSE
1498                           (proto0 == SNAT_PROTOCOL_UDP
1499                            && (vnet_buffer (b0)->ip.reass.l4_dst_port ==
1500                                clib_host_to_net_u16
1501                                (UDP_DST_PORT_dhcp_to_server))
1502                            && ip0->dst_address.as_u32 == 0xffffffff))
1503                         goto trace0;
1504                     }
1505                   else
1506                     {
1507                       if (PREDICT_FALSE
1508                           (snat_not_translate
1509                            (sm, node, sw_if_index0, ip0, proto0,
1510                             rx_fib_index0, thread_index)))
1511                         goto trace0;
1512                     }
1513
1514                   next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0,
1515                                      &s0, node, next0, thread_index, now);
1516
1517                   if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
1518                     goto trace0;
1519
1520                   if (PREDICT_FALSE (!s0))
1521                     goto trace0;
1522                 }
1523               else
1524                 {
1525                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1526                   goto trace0;
1527                 }
1528             }
1529           else
1530             s0 =
1531               pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
1532                                  value0.value);
1533
1534           b0->flags |= VNET_BUFFER_F_IS_NATED;
1535
1536           old_addr0 = ip0->src_address.as_u32;
1537           ip0->src_address = s0->out2in.addr;
1538           new_addr0 = ip0->src_address.as_u32;
1539           if (!is_output_feature)
1540             vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
1541
1542           sum0 = ip0->checksum;
1543           sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1544                                  ip4_header_t,
1545                                  src_address /* changed member */ );
1546           ip0->checksum = ip_csum_fold (sum0);
1547
1548           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
1549             {
1550               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1551                 {
1552                   old_port0 = vnet_buffer (b0)->ip.reass.l4_src_port;
1553                   new_port0 = udp0->src_port = s0->out2in.port;
1554                   sum0 = tcp0->checksum;
1555                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1556                                          ip4_header_t,
1557                                          dst_address /* changed member */ );
1558                   sum0 = ip_csum_update (sum0, old_port0, new_port0,
1559                                          ip4_header_t /* cheat */ ,
1560                                          length /* changed member */ );
1561                   mss_clamping (sm, tcp0, &sum0);
1562                   tcp0->checksum = ip_csum_fold (sum0);
1563                 }
1564               tcp_packets++;
1565             }
1566           else
1567             {
1568               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1569                 {
1570                   if (PREDICT_FALSE (udp0->checksum))
1571                     {
1572                       old_port0 = vnet_buffer (b0)->ip.reass.l4_src_port;
1573                       new_port0 = udp0->src_port = s0->out2in.port;
1574                       sum0 = udp0->checksum;
1575                       sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t, dst_address      /* changed member */
1576                         );
1577                       sum0 =
1578                         ip_csum_update (sum0, old_port0, new_port0,
1579                                         ip4_header_t /* cheat */ ,
1580                                         length /* changed member */ );
1581                       udp0->checksum = ip_csum_fold (sum0);
1582                     }
1583                 }
1584               udp_packets++;
1585             }
1586
1587           /* Accounting */
1588           nat44_session_update_counters (s0, now,
1589                                          vlib_buffer_length_in_chain (vm, b0),
1590                                          thread_index);
1591           /* Per-user LRU list maintenance */
1592           nat44_session_update_lru (sm, s0, thread_index);
1593
1594         trace0:
1595           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1596                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1597             {
1598               snat_in2out_trace_t *t =
1599                 vlib_add_trace (vm, node, b0, sizeof (*t));
1600               t->is_slow_path = is_slow_path;
1601               t->sw_if_index = sw_if_index0;
1602               t->next_index = next0;
1603               t->session_index = ~0;
1604               if (s0)
1605                 t->session_index =
1606                   s0 - sm->per_thread_data[thread_index].sessions;
1607             }
1608
1609           pkts_processed += next0 == SNAT_IN2OUT_NEXT_LOOKUP;
1610
1611           /* verify speculative enqueue, maybe switch current next frame */
1612           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1613                                            to_next, n_left_to_next,
1614                                            bi0, next0);
1615         }
1616
1617       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1618     }
1619
1620   vlib_node_increment_counter (vm, stats_node_index,
1621                                SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
1622                                pkts_processed);
1623   vlib_node_increment_counter (vm, stats_node_index,
1624                                SNAT_IN2OUT_ERROR_TCP_PACKETS, tcp_packets);
1625   vlib_node_increment_counter (vm, stats_node_index,
1626                                SNAT_IN2OUT_ERROR_UDP_PACKETS, udp_packets);
1627   vlib_node_increment_counter (vm, stats_node_index,
1628                                SNAT_IN2OUT_ERROR_ICMP_PACKETS, icmp_packets);
1629   vlib_node_increment_counter (vm, stats_node_index,
1630                                SNAT_IN2OUT_ERROR_OTHER_PACKETS,
1631                                other_packets);
1632   vlib_node_increment_counter (vm, stats_node_index,
1633                                SNAT_IN2OUT_ERROR_FRAGMENTS, fragments);
1634
1635   return frame->n_vectors;
1636 }
1637
1638 VLIB_NODE_FN (snat_in2out_node) (vlib_main_t * vm,
1639                                  vlib_node_runtime_t * node,
1640                                  vlib_frame_t * frame)
1641 {
1642   return snat_in2out_node_fn_inline (vm, node, frame, 0 /* is_slow_path */ ,
1643                                      0);
1644 }
1645
1646 /* *INDENT-OFF* */
1647 VLIB_REGISTER_NODE (snat_in2out_node) = {
1648   .name = "nat44-in2out",
1649   .vector_size = sizeof (u32),
1650   .format_trace = format_snat_in2out_trace,
1651   .type = VLIB_NODE_TYPE_INTERNAL,
1652
1653   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
1654   .error_strings = snat_in2out_error_strings,
1655
1656   .runtime_data_bytes = sizeof (snat_runtime_t),
1657
1658   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
1659
1660   /* edit / add dispositions here */
1661   .next_nodes = {
1662     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
1663     [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
1664     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
1665     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1666   },
1667 };
1668 /* *INDENT-ON* */
1669
1670 VLIB_NODE_FN (snat_in2out_output_node) (vlib_main_t * vm,
1671                                         vlib_node_runtime_t * node,
1672                                         vlib_frame_t * frame)
1673 {
1674   return snat_in2out_node_fn_inline (vm, node, frame, 0 /* is_slow_path */ ,
1675                                      1);
1676 }
1677
1678 /* *INDENT-OFF* */
1679 VLIB_REGISTER_NODE (snat_in2out_output_node) = {
1680   .name = "nat44-in2out-output",
1681   .vector_size = sizeof (u32),
1682   .format_trace = format_snat_in2out_trace,
1683   .type = VLIB_NODE_TYPE_INTERNAL,
1684
1685   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
1686   .error_strings = snat_in2out_error_strings,
1687
1688   .runtime_data_bytes = sizeof (snat_runtime_t),
1689
1690   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
1691
1692   /* edit / add dispositions here */
1693   .next_nodes = {
1694     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
1695     [SNAT_IN2OUT_NEXT_LOOKUP] = "interface-output",
1696     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-output-slowpath",
1697     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1698   },
1699 };
1700 /* *INDENT-ON* */
1701
1702 VLIB_NODE_FN (snat_in2out_slowpath_node) (vlib_main_t * vm,
1703                                           vlib_node_runtime_t * node,
1704                                           vlib_frame_t * frame)
1705 {
1706   return snat_in2out_node_fn_inline (vm, node, frame, 1 /* is_slow_path */ ,
1707                                      0);
1708 }
1709
1710 /* *INDENT-OFF* */
1711 VLIB_REGISTER_NODE (snat_in2out_slowpath_node) = {
1712   .name = "nat44-in2out-slowpath",
1713   .vector_size = sizeof (u32),
1714   .format_trace = format_snat_in2out_trace,
1715   .type = VLIB_NODE_TYPE_INTERNAL,
1716
1717   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
1718   .error_strings = snat_in2out_error_strings,
1719
1720   .runtime_data_bytes = sizeof (snat_runtime_t),
1721
1722   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
1723
1724   /* edit / add dispositions here */
1725   .next_nodes = {
1726     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
1727     [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
1728     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
1729     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1730   },
1731 };
1732 /* *INDENT-ON* */
1733
1734 VLIB_NODE_FN (snat_in2out_output_slowpath_node) (vlib_main_t * vm,
1735                                                  vlib_node_runtime_t * node,
1736                                                  vlib_frame_t * frame)
1737 {
1738   return snat_in2out_node_fn_inline (vm, node, frame, 1 /* is_slow_path */ ,
1739                                      1);
1740 }
1741
1742 /* *INDENT-OFF* */
1743 VLIB_REGISTER_NODE (snat_in2out_output_slowpath_node) = {
1744   .name = "nat44-in2out-output-slowpath",
1745   .vector_size = sizeof (u32),
1746   .format_trace = format_snat_in2out_trace,
1747   .type = VLIB_NODE_TYPE_INTERNAL,
1748
1749   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
1750   .error_strings = snat_in2out_error_strings,
1751
1752   .runtime_data_bytes = sizeof (snat_runtime_t),
1753
1754   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
1755
1756   /* edit / add dispositions here */
1757   .next_nodes = {
1758     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
1759     [SNAT_IN2OUT_NEXT_LOOKUP] = "interface-output",
1760     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-output-slowpath",
1761     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1762   },
1763 };
1764 /* *INDENT-ON* */
1765
1766 VLIB_NODE_FN (snat_in2out_fast_node) (vlib_main_t * vm,
1767                                       vlib_node_runtime_t * node,
1768                                       vlib_frame_t * frame)
1769 {
1770   u32 n_left_from, *from, *to_next;
1771   snat_in2out_next_t next_index;
1772   u32 pkts_processed = 0;
1773   snat_main_t *sm = &snat_main;
1774   u32 stats_node_index;
1775
1776   stats_node_index = sm->in2out_fast_node_index;
1777
1778   from = vlib_frame_vector_args (frame);
1779   n_left_from = frame->n_vectors;
1780   next_index = node->cached_next_index;
1781
1782   while (n_left_from > 0)
1783     {
1784       u32 n_left_to_next;
1785
1786       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1787
1788       while (n_left_from > 0 && n_left_to_next > 0)
1789         {
1790           u32 bi0;
1791           vlib_buffer_t *b0;
1792           u32 next0;
1793           u32 sw_if_index0;
1794           ip4_header_t *ip0;
1795           ip_csum_t sum0;
1796           u32 new_addr0, old_addr0;
1797           u16 old_port0, new_port0;
1798           udp_header_t *udp0;
1799           tcp_header_t *tcp0;
1800           icmp46_header_t *icmp0;
1801           snat_session_key_t key0, sm0;
1802           u32 proto0;
1803           u32 rx_fib_index0;
1804
1805           /* speculatively enqueue b0 to the current next frame */
1806           bi0 = from[0];
1807           to_next[0] = bi0;
1808           from += 1;
1809           to_next += 1;
1810           n_left_from -= 1;
1811           n_left_to_next -= 1;
1812
1813           b0 = vlib_get_buffer (vm, bi0);
1814           next0 = SNAT_IN2OUT_NEXT_LOOKUP;
1815
1816           ip0 = vlib_buffer_get_current (b0);
1817           udp0 = ip4_next_header (ip0);
1818           tcp0 = (tcp_header_t *) udp0;
1819           icmp0 = (icmp46_header_t *) udp0;
1820
1821           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1822           rx_fib_index0 =
1823             ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
1824
1825           if (PREDICT_FALSE (ip0->ttl == 1))
1826             {
1827               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1828               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1829                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1830                                            0);
1831               next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
1832               goto trace0;
1833             }
1834
1835           proto0 = ip_proto_to_snat_proto (ip0->protocol);
1836
1837           if (PREDICT_FALSE (proto0 == ~0))
1838             goto trace0;
1839
1840           if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1841             {
1842               next0 = icmp_in2out (sm, b0, ip0, icmp0, sw_if_index0,
1843                                    rx_fib_index0, node, next0, ~0, 0, 0);
1844               goto trace0;
1845             }
1846
1847           key0.addr = ip0->src_address;
1848           key0.protocol = proto0;
1849           key0.port = udp0->src_port;
1850           key0.fib_index = rx_fib_index0;
1851
1852           if (snat_static_mapping_match (sm, key0, &sm0, 0, 0, 0, 0, 0, 0))
1853             {
1854               b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
1855               next0 = SNAT_IN2OUT_NEXT_DROP;
1856               goto trace0;
1857             }
1858
1859           new_addr0 = sm0.addr.as_u32;
1860           new_port0 = sm0.port;
1861           vnet_buffer (b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
1862           old_addr0 = ip0->src_address.as_u32;
1863           ip0->src_address.as_u32 = new_addr0;
1864
1865           sum0 = ip0->checksum;
1866           sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1867                                  ip4_header_t,
1868                                  src_address /* changed member */ );
1869           ip0->checksum = ip_csum_fold (sum0);
1870
1871           if (PREDICT_FALSE (new_port0 != udp0->dst_port))
1872             {
1873               old_port0 = udp0->src_port;
1874               udp0->src_port = new_port0;
1875
1876               if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
1877                 {
1878                   sum0 = tcp0->checksum;
1879                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1880                                          ip4_header_t,
1881                                          dst_address /* changed member */ );
1882                   sum0 = ip_csum_update (sum0, old_port0, new_port0,
1883                                          ip4_header_t /* cheat */ ,
1884                                          length /* changed member */ );
1885                   mss_clamping (sm, tcp0, &sum0);
1886                   tcp0->checksum = ip_csum_fold (sum0);
1887                 }
1888               else if (udp0->checksum)
1889                 {
1890                   sum0 = udp0->checksum;
1891                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1892                                          ip4_header_t,
1893                                          dst_address /* changed member */ );
1894                   sum0 = ip_csum_update (sum0, old_port0, new_port0,
1895                                          ip4_header_t /* cheat */ ,
1896                                          length /* changed member */ );
1897                   udp0->checksum = ip_csum_fold (sum0);
1898                 }
1899             }
1900           else
1901             {
1902               if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
1903                 {
1904                   sum0 = tcp0->checksum;
1905                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1906                                          ip4_header_t,
1907                                          dst_address /* changed member */ );
1908                   mss_clamping (sm, tcp0, &sum0);
1909                   tcp0->checksum = ip_csum_fold (sum0);
1910                 }
1911               else if (udp0->checksum)
1912                 {
1913                   sum0 = udp0->checksum;
1914                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1915                                          ip4_header_t,
1916                                          dst_address /* changed member */ );
1917                   udp0->checksum = ip_csum_fold (sum0);
1918                 }
1919             }
1920
1921           /* Hairpinning */
1922           snat_hairpinning (sm, b0, ip0, udp0, tcp0, proto0, 0);
1923
1924         trace0:
1925           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1926                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1927             {
1928               snat_in2out_trace_t *t =
1929                 vlib_add_trace (vm, node, b0, sizeof (*t));
1930               t->sw_if_index = sw_if_index0;
1931               t->next_index = next0;
1932             }
1933
1934           pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
1935
1936           /* verify speculative enqueue, maybe switch current next frame */
1937           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1938                                            to_next, n_left_to_next,
1939                                            bi0, next0);
1940         }
1941
1942       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1943     }
1944
1945   vlib_node_increment_counter (vm, stats_node_index,
1946                                SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
1947                                pkts_processed);
1948   return frame->n_vectors;
1949 }
1950
1951
1952 /* *INDENT-OFF* */
1953 VLIB_REGISTER_NODE (snat_in2out_fast_node) = {
1954   .name = "nat44-in2out-fast",
1955   .vector_size = sizeof (u32),
1956   .format_trace = format_snat_in2out_fast_trace,
1957   .type = VLIB_NODE_TYPE_INTERNAL,
1958
1959   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
1960   .error_strings = snat_in2out_error_strings,
1961
1962   .runtime_data_bytes = sizeof (snat_runtime_t),
1963
1964   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
1965
1966   /* edit / add dispositions here */
1967   .next_nodes = {
1968     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
1969     [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
1970     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
1971     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1972   },
1973 };
1974 /* *INDENT-ON* */
1975
1976 /*
1977  * fd.io coding-style-patch-verification: ON
1978  *
1979  * Local Variables:
1980  * eval: (c-set-style "gnu")
1981  * End:
1982  */