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   u32 sw_if_index0;
 464   u32 rx_fib_index0;
 465   snat_session_key_t key0;
 466   snat_session_t *s0 = 0;
 467   u8 dont_translate = 0;
 468   clib_bihash_kv_8_8_t kv0, value0;
 469   u32 next0 = ~0;
 470   int err;
 471
 472   sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 473   rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
 474
 475   err = icmp_get_key (b0, ip0, &key0);
 476   if (err != -1)
 477     {
 478       b0->error = node->errors[err];
 479       next0 = SNAT_IN2OUT_NEXT_DROP;
 480       goto out;
 481     }
 482   key0.fib_index = rx_fib_index0;
 483
 484   kv0.key = key0.as_u64;
 485
 486   if (clib_bihash_search_8_8 (&sm->per_thread_data[thread_index].in2out, &kv0,
 487                               &value0))
 488     {
 489       if (vnet_buffer (b0)->sw_if_index[VLIB_TX] != ~0)
 490         {
 491           if (PREDICT_FALSE (nat_not_translate_output_feature (sm, ip0,
 492                                                                key0.protocol,
 493                                                                key0.port,
 494                                                                key0.port,
 495                                                                thread_index,
 496                                                                sw_if_index0)))
 497             {
 498               dont_translate = 1;
 499               goto out;
 500             }
 501         }
 502       else
 503         {
 504           if (PREDICT_FALSE (snat_not_translate (sm, node, sw_if_index0,
 505                                                  ip0, SNAT_PROTOCOL_ICMP,
 506                                                  rx_fib_index0,
 507                                                  thread_index)))
 508             {
 509               dont_translate = 1;
 510               goto out;
 511             }
 512         }
 513
 514       if (PREDICT_FALSE
 515           (icmp_type_is_error_message
 516            (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags)))
 517         {
 518           b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
 519           next0 = SNAT_IN2OUT_NEXT_DROP;
 520           goto out;
 521         }
 522
 523       next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0, &s0, node, next0,
 524                          thread_index, vlib_time_now (sm->vlib_main));
 525
 526       if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
 527         goto out;
 528
 529       if (!s0)
 530         {
 531           dont_translate = 1;
 532           goto out;
 533         }
 534     }
 535   else
 536     {
 537       if (PREDICT_FALSE
 538           (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
 539            ICMP4_echo_request
 540            && vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
 541            ICMP4_echo_reply
 542            && !icmp_type_is_error_message (vnet_buffer (b0)->ip.
 543                                            reass.icmp_type_or_tcp_flags)))
 544         {
 545           b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
 546           next0 = SNAT_IN2OUT_NEXT_DROP;
 547           goto out;
 548         }
 549
 550       s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
 551                               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   snat_session_key_t sm0;
 664   u8 protocol;
 665   icmp_echo_header_t *echo0, *inner_echo0 = 0;
 666   ip4_header_t *inner_ip0;
 667   void *l4_header = 0;
 668   icmp46_header_t *inner_icmp0;
 669   u8 dont_translate;
 670   u32 new_addr0, old_addr0;
 671   u16 old_id0, new_id0;
 672   u16 old_checksum0, new_checksum0;
 673   ip_csum_t sum0;
 674   u16 checksum0;
 675   u32 next0_tmp;
 676
 677   echo0 = (icmp_echo_header_t *) (icmp0 + 1);
 678
 679   next0_tmp = sm->icmp_match_in2out_cb (sm, node, thread_index, b0, ip0,
 680                                         &protocol, &sm0, &dont_translate, d,
 681                                         e);
 682   if (next0_tmp != ~0)
 683     next0 = next0_tmp;
 684   if (next0 == SNAT_IN2OUT_NEXT_DROP || dont_translate)
 685     goto out;
 686
 687   if (PREDICT_TRUE (!ip4_is_fragment (ip0)))
 688     {
 689       sum0 = ip_incremental_checksum_buffer (sm->vlib_main, b0, (u8 *) icmp0 -
 690                                              (u8 *)
 691                                              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 = sm0.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 = sm0.port;
 718           if (PREDICT_FALSE (new_id0 != echo0->identifier))
 719             {
 720               old_id0 = echo0->identifier;
 721               new_id0 = sm0.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 = sm0.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 SNAT_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 = sm0.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 SNAT_PROTOCOL_UDP:
 781             case SNAT_PROTOCOL_TCP:
 782               old_id0 = ((tcp_udp_header_t *) l4_header)->dst_port;
 783               new_id0 = sm0.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] = sm0.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   next0 = icmp_in2out (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
 822                        next0, thread_index, p_s0, 0);
 823   snat_session_t *s0 = *p_s0;
 824   if (PREDICT_TRUE (next0 != SNAT_IN2OUT_NEXT_DROP && s0))
 825     {
 826       /* Accounting */
 827       nat44_session_update_counters (s0, now,
 828                                      vlib_buffer_length_in_chain
 829                                      (sm->vlib_main, b0), thread_index);
 830       /* Per-user LRU list maintenance */
 831       nat44_session_update_lru (sm, s0, thread_index);
 832     }
 833   return next0;
 834 }
 835
 836 static int
 837 nat_in2out_sm_unknown_proto (snat_main_t * sm,
 838                              vlib_buffer_t * b,
 839                              ip4_header_t * ip, u32 rx_fib_index)
 840 {
 841   clib_bihash_kv_8_8_t kv, value;
 842   snat_static_mapping_t *m;
 843   snat_session_key_t m_key;
 844   u32 old_addr, new_addr;
 845   ip_csum_t sum;
 846
 847   m_key.addr = ip->src_address;
 848   m_key.port = 0;
 849   m_key.protocol = 0;
 850   m_key.fib_index = rx_fib_index;
 851   kv.key = m_key.as_u64;
 852   if (clib_bihash_search_8_8 (&sm->static_mapping_by_local, &kv, &value))
 853     return 1;
 854
 855   m = pool_elt_at_index (sm->static_mappings, value.value);
 856
 857   old_addr = ip->src_address.as_u32;
 858   new_addr = ip->src_address.as_u32 = m->external_addr.as_u32;
 859   sum = ip->checksum;
 860   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, src_address);
 861   ip->checksum = ip_csum_fold (sum);
 862
 863
 864   /* Hairpinning */
 865   if (vnet_buffer (b)->sw_if_index[VLIB_TX] == ~0)
 866     {
 867       vnet_buffer (b)->sw_if_index[VLIB_TX] = m->fib_index;
 868       nat_hairpinning_sm_unknown_proto (sm, b, ip);
 869     }
 870
 871   return 0;
 872 }
 873
 874 static inline uword
 875 snat_in2out_node_fn_inline (vlib_main_t * vm,
 876                             vlib_node_runtime_t * node,
 877                             vlib_frame_t * frame, int is_slow_path,
 878                             int is_output_feature)
 879 {
 880   u32 n_left_from, *from, *to_next;
 881   snat_in2out_next_t next_index;
 882   u32 pkts_processed = 0;
 883   snat_main_t *sm = &snat_main;
 884   f64 now = vlib_time_now (vm);
 885   u32 stats_node_index;
 886   u32 thread_index = vm->thread_index;
 887   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
 888     0, fragments = 0;
 889
 890   stats_node_index = is_slow_path ? sm->in2out_slowpath_node_index :
 891     sm->in2out_node_index;
 892
 893   from = vlib_frame_vector_args (frame);
 894   n_left_from = frame->n_vectors;
 895   next_index = node->cached_next_index;
 896
 897   while (n_left_from > 0)
 898     {
 899       u32 n_left_to_next;
 900
 901       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 902
 903       while (n_left_from >= 4 && n_left_to_next >= 2)
 904         {
 905           u32 bi0, bi1;
 906           vlib_buffer_t *b0, *b1;
 907           u32 next0, next1;
 908           u32 sw_if_index0, sw_if_index1;
 909           ip4_header_t *ip0, *ip1;
 910           ip_csum_t sum0, sum1;
 911           u32 new_addr0, old_addr0, new_addr1, old_addr1;
 912           u16 old_port0, new_port0, old_port1, new_port1;
 913           udp_header_t *udp0, *udp1;
 914           tcp_header_t *tcp0, *tcp1;
 915           icmp46_header_t *icmp0, *icmp1;
 916           snat_session_key_t key0, key1;
 917           u32 rx_fib_index0, rx_fib_index1;
 918           u32 proto0, proto1;
 919           snat_session_t *s0 = 0, *s1 = 0;
 920           clib_bihash_kv_8_8_t kv0, value0, kv1, value1;
 921           u32 iph_offset0 = 0, iph_offset1 = 0;
 922
 923           /* Prefetch next iteration. */
 924           {
 925             vlib_buffer_t *p2, *p3;
 926
 927             p2 = vlib_get_buffer (vm, from[2]);
 928             p3 = vlib_get_buffer (vm, from[3]);
 929
 930             vlib_prefetch_buffer_header (p2, LOAD);
 931             vlib_prefetch_buffer_header (p3, LOAD);
 932
 933             CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE);
 934             CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE);
 935           }
 936
 937           /* speculatively enqueue b0 and b1 to the current next frame */
 938           to_next[0] = bi0 = from[0];
 939           to_next[1] = bi1 = from[1];
 940           from += 2;
 941           to_next += 2;
 942           n_left_from -= 2;
 943           n_left_to_next -= 2;
 944
 945           b0 = vlib_get_buffer (vm, bi0);
 946           b1 = vlib_get_buffer (vm, bi1);
 947
 948           if (is_output_feature)
 949             iph_offset0 = vnet_buffer (b0)->ip.reass.save_rewrite_length;
 950
 951           ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
 952                                   iph_offset0);
 953
 954           udp0 = ip4_next_header (ip0);
 955           tcp0 = (tcp_header_t *) udp0;
 956           icmp0 = (icmp46_header_t *) udp0;
 957
 958           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 959           rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
 960                                    sw_if_index0);
 961
 962           next0 = next1 = SNAT_IN2OUT_NEXT_LOOKUP;
 963
 964           if (PREDICT_FALSE (ip0->ttl == 1))
 965             {
 966               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 967               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 968                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 969                                            0);
 970               next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
 971               goto trace00;
 972             }
 973
 974           proto0 = ip_proto_to_snat_proto (ip0->protocol);
 975
 976           /* Next configured feature, probably ip4-lookup */
 977           if (is_slow_path)
 978             {
 979               if (PREDICT_FALSE (proto0 == ~0))
 980                 {
 981                   if (nat_in2out_sm_unknown_proto
 982                       (sm, b0, ip0, rx_fib_index0))
 983                     {
 984                       next0 = SNAT_IN2OUT_NEXT_DROP;
 985                       b0->error =
 986                         node->errors[SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL];
 987                     }
 988                   other_packets++;
 989                   goto trace00;
 990                 }
 991
 992               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
 993                 {
 994                   next0 = icmp_in2out_slow_path
 995                     (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0,
 996                      node, next0, now, thread_index, &s0);
 997                   icmp_packets++;
 998                   goto trace00;
 999                 }
1000             }
1001           else
1002             {
1003               if (PREDICT_FALSE (proto0 == ~0))
1004                 {
1005                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1006                   goto trace00;
1007                 }
1008
1009               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1010                 {
1011                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1012                   goto trace00;
1013                 }
1014             }
1015
1016           key0.addr = ip0->src_address;
1017           key0.port = vnet_buffer (b0)->ip.reass.l4_src_port;
1018           key0.protocol = proto0;
1019           key0.fib_index = rx_fib_index0;
1020
1021           kv0.key = key0.as_u64;
1022
1023           if (PREDICT_FALSE
1024               (clib_bihash_search_8_8
1025                (&sm->per_thread_data[thread_index].in2out, &kv0,
1026                 &value0) != 0))
1027             {
1028               if (is_slow_path)
1029                 {
1030                   if (is_output_feature)
1031                     {
1032                       if (PREDICT_FALSE
1033                           (nat_not_translate_output_feature
1034                            (sm, ip0, proto0,
1035                             vnet_buffer (b0)->ip.reass.l4_src_port,
1036                             vnet_buffer (b0)->ip.reass.l4_dst_port,
1037                             thread_index, sw_if_index0)))
1038                         goto trace00;
1039
1040                       /*
1041                        * Send DHCP packets to the ipv4 stack, or we won't
1042                        * be able to use dhcp client on the outside interface
1043                        */
1044                       if (PREDICT_FALSE
1045                           (proto0 == SNAT_PROTOCOL_UDP
1046                            && (vnet_buffer (b0)->ip.reass.l4_dst_port ==
1047                                clib_host_to_net_u16
1048                                (UDP_DST_PORT_dhcp_to_server))
1049                            && ip0->dst_address.as_u32 == 0xffffffff))
1050                         goto trace00;
1051                     }
1052                   else
1053                     {
1054                       if (PREDICT_FALSE
1055                           (snat_not_translate
1056                            (sm, node, sw_if_index0, ip0, proto0,
1057                             rx_fib_index0, thread_index)))
1058                         goto trace00;
1059                     }
1060
1061                   next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0,
1062                                      &s0, node, next0, thread_index, now);
1063                   if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
1064                     goto trace00;
1065
1066                   if (PREDICT_FALSE (!s0))
1067                     goto trace00;
1068                 }
1069               else
1070                 {
1071                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1072                   goto trace00;
1073                 }
1074             }
1075           else
1076             s0 =
1077               pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
1078                                  value0.value);
1079
1080           b0->flags |= VNET_BUFFER_F_IS_NATED;
1081
1082           old_addr0 = ip0->src_address.as_u32;
1083           ip0->src_address = s0->out2in.addr;
1084           new_addr0 = ip0->src_address.as_u32;
1085           if (!is_output_feature)
1086             vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
1087
1088           sum0 = ip0->checksum;
1089           sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1090                                  ip4_header_t,
1091                                  src_address /* changed member */ );
1092           ip0->checksum = ip_csum_fold (sum0);
1093
1094
1095           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
1096             {
1097               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1098                 {
1099                   old_port0 = vnet_buffer (b0)->ip.reass.l4_src_port;
1100                   new_port0 = udp0->src_port = s0->out2in.port;
1101                   sum0 = tcp0->checksum;
1102                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1103                                          ip4_header_t,
1104                                          dst_address /* changed member */ );
1105                   sum0 = ip_csum_update (sum0, old_port0, new_port0,
1106                                          ip4_header_t /* cheat */ ,
1107                                          length /* changed member */ );
1108                   mss_clamping (sm, tcp0, &sum0);
1109                   tcp0->checksum = ip_csum_fold (sum0);
1110                 }
1111               tcp_packets++;
1112             }
1113           else
1114             {
1115               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1116                 {
1117                   if (PREDICT_FALSE (udp0->checksum))
1118                     {
1119                       old_port0 = vnet_buffer (b0)->ip.reass.l4_src_port;
1120                       new_port0 = udp0->src_port = s0->out2in.port;
1121                       sum0 = udp0->checksum;
1122                       sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t, dst_address      /* changed member */
1123                         );
1124                       sum0 =
1125                         ip_csum_update (sum0, old_port0, new_port0,
1126                                         ip4_header_t /* cheat */ ,
1127                                         length /* changed member */ );
1128                       udp0->checksum = ip_csum_fold (sum0);
1129                     }
1130                 }
1131               udp_packets++;
1132             }
1133
1134           /* Accounting */
1135           nat44_session_update_counters (s0, now,
1136                                          vlib_buffer_length_in_chain (vm, b0),
1137                                          thread_index);
1138           /* Per-user LRU list maintenance */
1139           nat44_session_update_lru (sm, s0, thread_index);
1140         trace00:
1141
1142           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1143                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1144             {
1145               snat_in2out_trace_t *t =
1146                 vlib_add_trace (vm, node, b0, sizeof (*t));
1147               t->is_slow_path = is_slow_path;
1148               t->sw_if_index = sw_if_index0;
1149               t->next_index = next0;
1150               t->session_index = ~0;
1151               if (s0)
1152                 t->session_index =
1153                   s0 - sm->per_thread_data[thread_index].sessions;
1154             }
1155
1156           pkts_processed += next0 == SNAT_IN2OUT_NEXT_LOOKUP;
1157
1158           if (is_output_feature)
1159             iph_offset1 = vnet_buffer (b1)->ip.reass.save_rewrite_length;
1160
1161           ip1 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b1) +
1162                                   iph_offset1);
1163
1164           udp1 = ip4_next_header (ip1);
1165           tcp1 = (tcp_header_t *) udp1;
1166           icmp1 = (icmp46_header_t *) udp1;
1167
1168           sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];
1169           rx_fib_index1 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
1170                                    sw_if_index1);
1171
1172           if (PREDICT_FALSE (ip1->ttl == 1))
1173             {
1174               vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1175               icmp4_error_set_vnet_buffer (b1, ICMP4_time_exceeded,
1176                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1177                                            0);
1178               next1 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
1179               goto trace01;
1180             }
1181
1182           proto1 = ip_proto_to_snat_proto (ip1->protocol);
1183
1184           /* Next configured feature, probably ip4-lookup */
1185           if (is_slow_path)
1186             {
1187               if (PREDICT_FALSE (proto1 == ~0))
1188                 {
1189                   if (nat_in2out_sm_unknown_proto
1190                       (sm, b1, ip1, rx_fib_index1))
1191                     {
1192                       next1 = SNAT_IN2OUT_NEXT_DROP;
1193                       b1->error =
1194                         node->errors[SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL];
1195                     }
1196                   other_packets++;
1197                   goto trace01;
1198                 }
1199
1200               if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP))
1201                 {
1202                   next1 = icmp_in2out_slow_path
1203                     (sm, b1, ip1, icmp1, sw_if_index1, rx_fib_index1, node,
1204                      next1, now, thread_index, &s1);
1205                   icmp_packets++;
1206                   goto trace01;
1207                 }
1208             }
1209           else
1210             {
1211               if (PREDICT_FALSE (proto1 == ~0))
1212                 {
1213                   next1 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1214                   goto trace01;
1215                 }
1216
1217               if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP))
1218                 {
1219                   next1 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1220                   goto trace01;
1221                 }
1222             }
1223
1224           key1.addr = ip1->src_address;
1225           key1.port = vnet_buffer (b1)->ip.reass.l4_src_port;
1226           key1.protocol = proto1;
1227           key1.fib_index = rx_fib_index1;
1228
1229           kv1.key = key1.as_u64;
1230
1231           if (PREDICT_FALSE
1232               (clib_bihash_search_8_8
1233                (&sm->per_thread_data[thread_index].in2out, &kv1,
1234                 &value1) != 0))
1235             {
1236               if (is_slow_path)
1237                 {
1238                   if (is_output_feature)
1239                     {
1240                       if (PREDICT_FALSE
1241                           (nat_not_translate_output_feature
1242                            (sm, ip1, proto1,
1243                             vnet_buffer (b1)->ip.reass.l4_src_port,
1244                             vnet_buffer (b1)->ip.reass.l4_dst_port,
1245                             thread_index, sw_if_index1)))
1246                         goto trace01;
1247
1248                       /*
1249                        * Send DHCP packets to the ipv4 stack, or we won't
1250                        * be able to use dhcp client on the outside interface
1251                        */
1252                       if (PREDICT_FALSE
1253                           (proto1 == SNAT_PROTOCOL_UDP
1254                            && (vnet_buffer (b1)->ip.reass.l4_dst_port ==
1255                                clib_host_to_net_u16
1256                                (UDP_DST_PORT_dhcp_to_server))
1257                            && ip1->dst_address.as_u32 == 0xffffffff))
1258                         goto trace01;
1259                     }
1260                   else
1261                     {
1262                       if (PREDICT_FALSE
1263                           (snat_not_translate
1264                            (sm, node, sw_if_index1, ip1, proto1,
1265                             rx_fib_index1, thread_index)))
1266                         goto trace01;
1267                     }
1268
1269                   next1 = slow_path (sm, b1, ip1, rx_fib_index1, &key1,
1270                                      &s1, node, next1, thread_index, now);
1271                   if (PREDICT_FALSE (next1 == SNAT_IN2OUT_NEXT_DROP))
1272                     goto trace01;
1273
1274                   if (PREDICT_FALSE (!s1))
1275                     goto trace01;
1276                 }
1277               else
1278                 {
1279                   next1 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1280                   goto trace01;
1281                 }
1282             }
1283           else
1284             s1 =
1285               pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
1286                                  value1.value);
1287
1288           b1->flags |= VNET_BUFFER_F_IS_NATED;
1289
1290           old_addr1 = ip1->src_address.as_u32;
1291           ip1->src_address = s1->out2in.addr;
1292           new_addr1 = ip1->src_address.as_u32;
1293           if (!is_output_feature)
1294             vnet_buffer (b1)->sw_if_index[VLIB_TX] = s1->out2in.fib_index;
1295
1296           sum1 = ip1->checksum;
1297           sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
1298                                  ip4_header_t,
1299                                  src_address /* changed member */ );
1300           ip1->checksum = ip_csum_fold (sum1);
1301
1302           if (PREDICT_TRUE (proto1 == SNAT_PROTOCOL_TCP))
1303             {
1304               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1305                 {
1306                   old_port1 = vnet_buffer (b1)->ip.reass.l4_src_port;
1307                   new_port1 = udp1->src_port = s1->out2in.port;
1308                   sum1 = tcp1->checksum;
1309                   sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
1310                                          ip4_header_t,
1311                                          dst_address /* changed member */ );
1312                   sum1 = ip_csum_update (sum1, old_port1, new_port1,
1313                                          ip4_header_t /* cheat */ ,
1314                                          length /* changed member */ );
1315                   mss_clamping (sm, tcp1, &sum1);
1316                   tcp1->checksum = ip_csum_fold (sum1);
1317                 }
1318               tcp_packets++;
1319             }
1320           else
1321             {
1322               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1323                 {
1324                   if (PREDICT_FALSE (udp1->checksum))
1325                     {
1326                       old_port1 = vnet_buffer (b1)->ip.reass.l4_src_port;
1327                       new_port1 = udp1->src_port = s1->out2in.port;
1328                       sum1 = udp1->checksum;
1329                       sum1 = ip_csum_update (sum1, old_addr1, new_addr1, ip4_header_t, dst_address      /* changed member */
1330                         );
1331                       sum1 =
1332                         ip_csum_update (sum1, old_port1, new_port1,
1333                                         ip4_header_t /* cheat */ ,
1334                                         length /* changed member */ );
1335                       udp1->checksum = ip_csum_fold (sum1);
1336                     }
1337                 }
1338               udp_packets++;
1339             }
1340
1341           /* Accounting */
1342           nat44_session_update_counters (s1, now,
1343                                          vlib_buffer_length_in_chain (vm, b1),
1344                                          thread_index);
1345           /* Per-user LRU list maintenance */
1346           nat44_session_update_lru (sm, s1, thread_index);
1347         trace01:
1348
1349           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1350                              && (b1->flags & VLIB_BUFFER_IS_TRACED)))
1351             {
1352               snat_in2out_trace_t *t =
1353                 vlib_add_trace (vm, node, b1, sizeof (*t));
1354               t->sw_if_index = sw_if_index1;
1355               t->next_index = next1;
1356               t->session_index = ~0;
1357               if (s1)
1358                 t->session_index =
1359                   s1 - sm->per_thread_data[thread_index].sessions;
1360             }
1361
1362           pkts_processed += next1 == SNAT_IN2OUT_NEXT_LOOKUP;
1363
1364           /* verify speculative enqueues, maybe switch current next frame */
1365           vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
1366                                            to_next, n_left_to_next,
1367                                            bi0, bi1, next0, next1);
1368         }
1369
1370       while (n_left_from > 0 && n_left_to_next > 0)
1371         {
1372           u32 bi0;
1373           vlib_buffer_t *b0;
1374           u32 next0;
1375           u32 sw_if_index0;
1376           ip4_header_t *ip0;
1377           ip_csum_t sum0;
1378           u32 new_addr0, old_addr0;
1379           u16 old_port0, new_port0;
1380           udp_header_t *udp0;
1381           tcp_header_t *tcp0;
1382           icmp46_header_t *icmp0;
1383           snat_session_key_t key0;
1384           u32 rx_fib_index0;
1385           u32 proto0;
1386           snat_session_t *s0 = 0;
1387           clib_bihash_kv_8_8_t kv0, value0;
1388           u32 iph_offset0 = 0;
1389
1390           /* speculatively enqueue b0 to the current next frame */
1391           bi0 = from[0];
1392           to_next[0] = bi0;
1393           from += 1;
1394           to_next += 1;
1395           n_left_from -= 1;
1396           n_left_to_next -= 1;
1397
1398           b0 = vlib_get_buffer (vm, bi0);
1399           next0 = SNAT_IN2OUT_NEXT_LOOKUP;
1400
1401           if (is_output_feature)
1402             iph_offset0 = vnet_buffer (b0)->ip.reass.save_rewrite_length;
1403
1404           ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
1405                                   iph_offset0);
1406
1407           udp0 = ip4_next_header (ip0);
1408           tcp0 = (tcp_header_t *) udp0;
1409           icmp0 = (icmp46_header_t *) udp0;
1410
1411           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1412           rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
1413                                    sw_if_index0);
1414
1415           if (PREDICT_FALSE (ip0->ttl == 1))
1416             {
1417               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1418               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1419                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1420                                            0);
1421               next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
1422               goto trace0;
1423             }
1424
1425           proto0 = ip_proto_to_snat_proto (ip0->protocol);
1426
1427           /* Next configured feature, probably ip4-lookup */
1428           if (is_slow_path)
1429             {
1430               if (PREDICT_FALSE (proto0 == ~0))
1431                 {
1432                   if (nat_in2out_sm_unknown_proto
1433                       (sm, b0, ip0, rx_fib_index0))
1434                     {
1435                       next0 = SNAT_IN2OUT_NEXT_DROP;
1436                       b0->error =
1437                         node->errors[SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL];
1438                     }
1439                   other_packets++;
1440                   goto trace0;
1441                 }
1442
1443               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1444                 {
1445                   next0 = icmp_in2out_slow_path
1446                     (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1447                      next0, now, thread_index, &s0);
1448                   icmp_packets++;
1449                   goto trace0;
1450                 }
1451             }
1452           else
1453             {
1454               if (PREDICT_FALSE (proto0 == ~0))
1455                 {
1456                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1457                   goto trace0;
1458                 }
1459
1460               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1461                 {
1462                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1463                   goto trace0;
1464                 }
1465             }
1466
1467           key0.addr = ip0->src_address;
1468           key0.port = vnet_buffer (b0)->ip.reass.l4_src_port;
1469           key0.protocol = proto0;
1470           key0.fib_index = rx_fib_index0;
1471
1472           kv0.key = key0.as_u64;
1473
1474           if (clib_bihash_search_8_8
1475               (&sm->per_thread_data[thread_index].in2out, &kv0, &value0))
1476             {
1477               if (is_slow_path)
1478                 {
1479                   if (is_output_feature)
1480                     {
1481                       if (PREDICT_FALSE
1482                           (nat_not_translate_output_feature
1483                            (sm, ip0, proto0,
1484                             vnet_buffer (b0)->ip.reass.l4_src_port,
1485                             vnet_buffer (b0)->ip.reass.l4_dst_port,
1486                             thread_index, sw_if_index0)))
1487                         goto trace0;
1488
1489                       /*
1490                        * Send DHCP packets to the ipv4 stack, or we won't
1491                        * be able to use dhcp client on the outside interface
1492                        */
1493                       if (PREDICT_FALSE
1494                           (proto0 == SNAT_PROTOCOL_UDP
1495                            && (vnet_buffer (b0)->ip.reass.l4_dst_port ==
1496                                clib_host_to_net_u16
1497                                (UDP_DST_PORT_dhcp_to_server))
1498                            && ip0->dst_address.as_u32 == 0xffffffff))
1499                         goto trace0;
1500                     }
1501                   else
1502                     {
1503                       if (PREDICT_FALSE
1504                           (snat_not_translate
1505                            (sm, node, sw_if_index0, ip0, proto0,
1506                             rx_fib_index0, thread_index)))
1507                         goto trace0;
1508                     }
1509
1510                   next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0,
1511                                      &s0, node, next0, thread_index, now);
1512
1513                   if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
1514                     goto trace0;
1515
1516                   if (PREDICT_FALSE (!s0))
1517                     goto trace0;
1518                 }
1519               else
1520                 {
1521                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1522                   goto trace0;
1523                 }
1524             }
1525           else
1526             s0 =
1527               pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
1528                                  value0.value);
1529
1530           b0->flags |= VNET_BUFFER_F_IS_NATED;
1531
1532           old_addr0 = ip0->src_address.as_u32;
1533           ip0->src_address = s0->out2in.addr;
1534           new_addr0 = ip0->src_address.as_u32;
1535           if (!is_output_feature)
1536             vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
1537
1538           sum0 = ip0->checksum;
1539           sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1540                                  ip4_header_t,
1541                                  src_address /* changed member */ );
1542           ip0->checksum = ip_csum_fold (sum0);
1543
1544           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
1545             {
1546               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1547                 {
1548                   old_port0 = vnet_buffer (b0)->ip.reass.l4_src_port;
1549                   new_port0 = udp0->src_port = s0->out2in.port;
1550                   sum0 = tcp0->checksum;
1551                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1552                                          ip4_header_t,
1553                                          dst_address /* changed member */ );
1554                   sum0 = ip_csum_update (sum0, old_port0, new_port0,
1555                                          ip4_header_t /* cheat */ ,
1556                                          length /* changed member */ );
1557                   mss_clamping (sm, tcp0, &sum0);
1558                   tcp0->checksum = ip_csum_fold (sum0);
1559                 }
1560               tcp_packets++;
1561             }
1562           else
1563             {
1564               if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
1565                 {
1566                   if (PREDICT_FALSE (udp0->checksum))
1567                     {
1568                       old_port0 = vnet_buffer (b0)->ip.reass.l4_src_port;
1569                       new_port0 = udp0->src_port = s0->out2in.port;
1570                       sum0 = udp0->checksum;
1571                       sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t, dst_address      /* changed member */
1572                         );
1573                       sum0 =
1574                         ip_csum_update (sum0, old_port0, new_port0,
1575                                         ip4_header_t /* cheat */ ,
1576                                         length /* changed member */ );
1577                       udp0->checksum = ip_csum_fold (sum0);
1578                     }
1579                 }
1580               udp_packets++;
1581             }
1582
1583           /* Accounting */
1584           nat44_session_update_counters (s0, now,
1585                                          vlib_buffer_length_in_chain (vm, b0),
1586                                          thread_index);
1587           /* Per-user LRU list maintenance */
1588           nat44_session_update_lru (sm, s0, thread_index);
1589
1590         trace0:
1591           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1592                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1593             {
1594               snat_in2out_trace_t *t =
1595                 vlib_add_trace (vm, node, b0, sizeof (*t));
1596               t->is_slow_path = is_slow_path;
1597               t->sw_if_index = sw_if_index0;
1598               t->next_index = next0;
1599               t->session_index = ~0;
1600               if (s0)
1601                 t->session_index =
1602                   s0 - sm->per_thread_data[thread_index].sessions;
1603             }
1604
1605           pkts_processed += next0 == SNAT_IN2OUT_NEXT_LOOKUP;
1606
1607           /* verify speculative enqueue, maybe switch current next frame */
1608           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1609                                            to_next, n_left_to_next,
1610                                            bi0, next0);
1611         }
1612
1613       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1614     }
1615
1616   vlib_node_increment_counter (vm, stats_node_index,
1617                                SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
1618                                pkts_processed);
1619   vlib_node_increment_counter (vm, stats_node_index,
1620                                SNAT_IN2OUT_ERROR_TCP_PACKETS, tcp_packets);
1621   vlib_node_increment_counter (vm, stats_node_index,
1622                                SNAT_IN2OUT_ERROR_UDP_PACKETS, udp_packets);
1623   vlib_node_increment_counter (vm, stats_node_index,
1624                                SNAT_IN2OUT_ERROR_ICMP_PACKETS, icmp_packets);
1625   vlib_node_increment_counter (vm, stats_node_index,
1626                                SNAT_IN2OUT_ERROR_OTHER_PACKETS,
1627                                other_packets);
1628   vlib_node_increment_counter (vm, stats_node_index,
1629                                SNAT_IN2OUT_ERROR_FRAGMENTS, fragments);
1630
1631   return frame->n_vectors;
1632 }
1633
1634 VLIB_NODE_FN (snat_in2out_node) (vlib_main_t * vm,
1635                                  vlib_node_runtime_t * node,
1636                                  vlib_frame_t * frame)
1637 {
1638   return snat_in2out_node_fn_inline (vm, node, frame, 0 /* is_slow_path */ ,
1639                                      0);
1640 }
1641
1642 /* *INDENT-OFF* */
1643 VLIB_REGISTER_NODE (snat_in2out_node) = {
1644   .name = "nat44-in2out",
1645   .vector_size = sizeof (u32),
1646   .format_trace = format_snat_in2out_trace,
1647   .type = VLIB_NODE_TYPE_INTERNAL,
1648
1649   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
1650   .error_strings = snat_in2out_error_strings,
1651
1652   .runtime_data_bytes = sizeof (snat_runtime_t),
1653
1654   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
1655
1656   /* edit / add dispositions here */
1657   .next_nodes = {
1658     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
1659     [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
1660     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
1661     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1662   },
1663 };
1664 /* *INDENT-ON* */
1665
1666 VLIB_NODE_FN (snat_in2out_output_node) (vlib_main_t * vm,
1667                                         vlib_node_runtime_t * node,
1668                                         vlib_frame_t * frame)
1669 {
1670   return snat_in2out_node_fn_inline (vm, node, frame, 0 /* is_slow_path */ ,
1671                                      1);
1672 }
1673
1674 /* *INDENT-OFF* */
1675 VLIB_REGISTER_NODE (snat_in2out_output_node) = {
1676   .name = "nat44-in2out-output",
1677   .vector_size = sizeof (u32),
1678   .format_trace = format_snat_in2out_trace,
1679   .type = VLIB_NODE_TYPE_INTERNAL,
1680
1681   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
1682   .error_strings = snat_in2out_error_strings,
1683
1684   .runtime_data_bytes = sizeof (snat_runtime_t),
1685
1686   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
1687
1688   /* edit / add dispositions here */
1689   .next_nodes = {
1690     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
1691     [SNAT_IN2OUT_NEXT_LOOKUP] = "interface-output",
1692     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-output-slowpath",
1693     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1694   },
1695 };
1696 /* *INDENT-ON* */
1697
1698 VLIB_NODE_FN (snat_in2out_slowpath_node) (vlib_main_t * vm,
1699                                           vlib_node_runtime_t * node,
1700                                           vlib_frame_t * frame)
1701 {
1702   return snat_in2out_node_fn_inline (vm, node, frame, 1 /* is_slow_path */ ,
1703                                      0);
1704 }
1705
1706 /* *INDENT-OFF* */
1707 VLIB_REGISTER_NODE (snat_in2out_slowpath_node) = {
1708   .name = "nat44-in2out-slowpath",
1709   .vector_size = sizeof (u32),
1710   .format_trace = format_snat_in2out_trace,
1711   .type = VLIB_NODE_TYPE_INTERNAL,
1712
1713   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
1714   .error_strings = snat_in2out_error_strings,
1715
1716   .runtime_data_bytes = sizeof (snat_runtime_t),
1717
1718   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
1719
1720   /* edit / add dispositions here */
1721   .next_nodes = {
1722     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
1723     [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
1724     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
1725     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1726   },
1727 };
1728 /* *INDENT-ON* */
1729
1730 VLIB_NODE_FN (snat_in2out_output_slowpath_node) (vlib_main_t * vm,
1731                                                  vlib_node_runtime_t * node,
1732                                                  vlib_frame_t * frame)
1733 {
1734   return snat_in2out_node_fn_inline (vm, node, frame, 1 /* is_slow_path */ ,
1735                                      1);
1736 }
1737
1738 /* *INDENT-OFF* */
1739 VLIB_REGISTER_NODE (snat_in2out_output_slowpath_node) = {
1740   .name = "nat44-in2out-output-slowpath",
1741   .vector_size = sizeof (u32),
1742   .format_trace = format_snat_in2out_trace,
1743   .type = VLIB_NODE_TYPE_INTERNAL,
1744
1745   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
1746   .error_strings = snat_in2out_error_strings,
1747
1748   .runtime_data_bytes = sizeof (snat_runtime_t),
1749
1750   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
1751
1752   /* edit / add dispositions here */
1753   .next_nodes = {
1754     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
1755     [SNAT_IN2OUT_NEXT_LOOKUP] = "interface-output",
1756     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-output-slowpath",
1757     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1758   },
1759 };
1760 /* *INDENT-ON* */
1761
1762 VLIB_NODE_FN (snat_in2out_fast_node) (vlib_main_t * vm,
1763                                       vlib_node_runtime_t * node,
1764                                       vlib_frame_t * frame)
1765 {
1766   u32 n_left_from, *from, *to_next;
1767   snat_in2out_next_t next_index;
1768   u32 pkts_processed = 0;
1769   snat_main_t *sm = &snat_main;
1770   u32 stats_node_index;
1771
1772   stats_node_index = sm->in2out_fast_node_index;
1773
1774   from = vlib_frame_vector_args (frame);
1775   n_left_from = frame->n_vectors;
1776   next_index = node->cached_next_index;
1777
1778   while (n_left_from > 0)
1779     {
1780       u32 n_left_to_next;
1781
1782       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1783
1784       while (n_left_from > 0 && n_left_to_next > 0)
1785         {
1786           u32 bi0;
1787           vlib_buffer_t *b0;
1788           u32 next0;
1789           u32 sw_if_index0;
1790           ip4_header_t *ip0;
1791           ip_csum_t sum0;
1792           u32 new_addr0, old_addr0;
1793           u16 old_port0, new_port0;
1794           udp_header_t *udp0;
1795           tcp_header_t *tcp0;
1796           icmp46_header_t *icmp0;
1797           snat_session_key_t key0, sm0;
1798           u32 proto0;
1799           u32 rx_fib_index0;
1800
1801           /* speculatively enqueue b0 to the current next frame */
1802           bi0 = from[0];
1803           to_next[0] = bi0;
1804           from += 1;
1805           to_next += 1;
1806           n_left_from -= 1;
1807           n_left_to_next -= 1;
1808
1809           b0 = vlib_get_buffer (vm, bi0);
1810           next0 = SNAT_IN2OUT_NEXT_LOOKUP;
1811
1812           ip0 = vlib_buffer_get_current (b0);
1813           udp0 = ip4_next_header (ip0);
1814           tcp0 = (tcp_header_t *) udp0;
1815           icmp0 = (icmp46_header_t *) udp0;
1816
1817           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1818           rx_fib_index0 =
1819             ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
1820
1821           if (PREDICT_FALSE (ip0->ttl == 1))
1822             {
1823               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1824               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1825                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1826                                            0);
1827               next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
1828               goto trace0;
1829             }
1830
1831           proto0 = ip_proto_to_snat_proto (ip0->protocol);
1832
1833           if (PREDICT_FALSE (proto0 == ~0))
1834             goto trace0;
1835
1836           if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1837             {
1838               next0 = icmp_in2out (sm, b0, ip0, icmp0, sw_if_index0,
1839                                    rx_fib_index0, node, next0, ~0, 0, 0);
1840               goto trace0;
1841             }
1842
1843           key0.addr = ip0->src_address;
1844           key0.protocol = proto0;
1845           key0.port = udp0->src_port;
1846           key0.fib_index = rx_fib_index0;
1847
1848           if (snat_static_mapping_match (sm, key0, &sm0, 0, 0, 0, 0, 0, 0))
1849             {
1850               b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
1851               next0 = SNAT_IN2OUT_NEXT_DROP;
1852               goto trace0;
1853             }
1854
1855           new_addr0 = sm0.addr.as_u32;
1856           new_port0 = sm0.port;
1857           vnet_buffer (b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
1858           old_addr0 = ip0->src_address.as_u32;
1859           ip0->src_address.as_u32 = new_addr0;
1860
1861           sum0 = ip0->checksum;
1862           sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1863                                  ip4_header_t,
1864                                  src_address /* changed member */ );
1865           ip0->checksum = ip_csum_fold (sum0);
1866
1867           if (PREDICT_FALSE (new_port0 != udp0->dst_port))
1868             {
1869               old_port0 = udp0->src_port;
1870               udp0->src_port = new_port0;
1871
1872               if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
1873                 {
1874                   sum0 = tcp0->checksum;
1875                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1876                                          ip4_header_t,
1877                                          dst_address /* changed member */ );
1878                   sum0 = ip_csum_update (sum0, old_port0, new_port0,
1879                                          ip4_header_t /* cheat */ ,
1880                                          length /* changed member */ );
1881                   mss_clamping (sm, tcp0, &sum0);
1882                   tcp0->checksum = ip_csum_fold (sum0);
1883                 }
1884               else if (udp0->checksum)
1885                 {
1886                   sum0 = udp0->checksum;
1887                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1888                                          ip4_header_t,
1889                                          dst_address /* changed member */ );
1890                   sum0 = ip_csum_update (sum0, old_port0, new_port0,
1891                                          ip4_header_t /* cheat */ ,
1892                                          length /* changed member */ );
1893                   udp0->checksum = ip_csum_fold (sum0);
1894                 }
1895             }
1896           else
1897             {
1898               if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
1899                 {
1900                   sum0 = tcp0->checksum;
1901                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1902                                          ip4_header_t,
1903                                          dst_address /* changed member */ );
1904                   mss_clamping (sm, tcp0, &sum0);
1905                   tcp0->checksum = ip_csum_fold (sum0);
1906                 }
1907               else if (udp0->checksum)
1908                 {
1909                   sum0 = udp0->checksum;
1910                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1911                                          ip4_header_t,
1912                                          dst_address /* changed member */ );
1913                   udp0->checksum = ip_csum_fold (sum0);
1914                 }
1915             }
1916
1917           /* Hairpinning */
1918           snat_hairpinning (sm, b0, ip0, udp0, tcp0, proto0, 0);
1919
1920         trace0:
1921           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1922                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1923             {
1924               snat_in2out_trace_t *t =
1925                 vlib_add_trace (vm, node, b0, sizeof (*t));
1926               t->sw_if_index = sw_if_index0;
1927               t->next_index = next0;
1928             }
1929
1930           pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
1931
1932           /* verify speculative enqueue, maybe switch current next frame */
1933           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1934                                            to_next, n_left_to_next,
1935                                            bi0, next0);
1936         }
1937
1938       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1939     }
1940
1941   vlib_node_increment_counter (vm, stats_node_index,
1942                                SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
1943                                pkts_processed);
1944   return frame->n_vectors;
1945 }
1946
1947
1948 /* *INDENT-OFF* */
1949 VLIB_REGISTER_NODE (snat_in2out_fast_node) = {
1950   .name = "nat44-in2out-fast",
1951   .vector_size = sizeof (u32),
1952   .format_trace = format_snat_in2out_fast_trace,
1953   .type = VLIB_NODE_TYPE_INTERNAL,
1954
1955   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
1956   .error_strings = snat_in2out_error_strings,
1957
1958   .runtime_data_bytes = sizeof (snat_runtime_t),
1959
1960   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
1961
1962   /* edit / add dispositions here */
1963   .next_nodes = {
1964     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
1965     [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
1966     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
1967     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1968   },
1969 };
1970 /* *INDENT-ON* */
1971
1972 /*
1973  * fd.io coding-style-patch-verification: ON
1974  *
1975  * Local Variables:
1976  * eval: (c-set-style "gnu")
1977  * End:
1978  */