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 <nat/nat.h>
  28 #include <nat/nat_ipfix_logging.h>
  29 #include <nat/nat_reass.h>
  30 #include <nat/nat_inlines.h>
  31 #include <nat/nat_syslog.h>
  32
  33 #include <vppinfra/hash.h>
  34 #include <vppinfra/error.h>
  35 #include <vppinfra/elog.h>
  36
  37 typedef struct
  38 {
  39   u32 sw_if_index;
  40   u32 next_index;
  41   u32 session_index;
  42   u32 is_slow_path;
  43 } snat_in2out_trace_t;
  44
  45 /* packet trace format function */
  46 static u8 *
  47 format_snat_in2out_trace (u8 * s, va_list * args)
  48 {
  49   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  50   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  51   snat_in2out_trace_t *t = va_arg (*args, snat_in2out_trace_t *);
  52   char *tag;
  53
  54   tag = t->is_slow_path ? "NAT44_IN2OUT_SLOW_PATH" : "NAT44_IN2OUT_FAST_PATH";
  55
  56   s = format (s, "%s: sw_if_index %d, next index %d, session %d", tag,
  57               t->sw_if_index, t->next_index, t->session_index);
  58
  59   return s;
  60 }
  61
  62 static u8 *
  63 format_snat_in2out_fast_trace (u8 * s, va_list * args)
  64 {
  65   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  66   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  67   snat_in2out_trace_t *t = va_arg (*args, snat_in2out_trace_t *);
  68
  69   s = format (s, "NAT44_IN2OUT_FAST: sw_if_index %d, next index %d",
  70               t->sw_if_index, t->next_index);
  71
  72   return s;
  73 }
  74
  75 vlib_node_registration_t snat_in2out_node;
  76 vlib_node_registration_t snat_in2out_slowpath_node;
  77 vlib_node_registration_t snat_in2out_fast_node;
  78 vlib_node_registration_t snat_in2out_output_node;
  79 vlib_node_registration_t snat_in2out_output_slowpath_node;
  80 vlib_node_registration_t nat44_in2out_reass_node;
  81
  82 #define foreach_snat_in2out_error                       \
  83 _(UNSUPPORTED_PROTOCOL, "Unsupported protocol")         \
  84 _(IN2OUT_PACKETS, "Good in2out packets processed")      \
  85 _(OUT_OF_PORTS, "Out of ports")                         \
  86 _(BAD_OUTSIDE_FIB, "Outside VRF ID not found")          \
  87 _(BAD_ICMP_TYPE, "unsupported ICMP type")               \
  88 _(NO_TRANSLATION, "No translation")                     \
  89 _(MAX_SESSIONS_EXCEEDED, "Maximum sessions exceeded")   \
  90 _(DROP_FRAGMENT, "Drop fragment")                       \
  91 _(MAX_REASS, "Maximum reassemblies exceeded")           \
  92 _(MAX_FRAG, "Maximum fragments per reassembly exceeded")
  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_NEXT_REASS,
 115   SNAT_IN2OUT_N_NEXT,
 116 } snat_in2out_next_t;
 117
 118 static inline int
 119 snat_not_translate (snat_main_t * sm, vlib_node_runtime_t * node,
 120                     u32 sw_if_index0, ip4_header_t * ip0, u32 proto0,
 121                     u32 rx_fib_index0, u32 thread_index)
 122 {
 123   udp_header_t *udp0 = ip4_next_header (ip0);
 124   snat_session_key_t key0, sm0;
 125   clib_bihash_kv_8_8_t kv0, value0;
 126
 127   key0.addr = ip0->dst_address;
 128   key0.port = udp0->dst_port;
 129   key0.protocol = proto0;
 130   key0.fib_index = sm->outside_fib_index;
 131   kv0.key = key0.as_u64;
 132
 133   /* NAT packet aimed at external address if */
 134   /* has active sessions */
 135   if (clib_bihash_search_8_8 (&sm->per_thread_data[thread_index].out2in, &kv0,
 136                               &value0))
 137     {
 138       /* or is static mappings */
 139       if (!snat_static_mapping_match (sm, key0, &sm0, 1, 0, 0, 0, 0, 0))
 140         return 0;
 141     }
 142   else
 143     return 0;
 144
 145   if (sm->forwarding_enabled)
 146     return 1;
 147
 148   return snat_not_translate_fast (sm, node, sw_if_index0, ip0, proto0,
 149                                   rx_fib_index0);
 150 }
 151
 152 static inline int
 153 nat_not_translate_output_feature (snat_main_t * sm, ip4_header_t * ip0,
 154                                   u32 proto0, u16 src_port, u16 dst_port,
 155                                   u32 thread_index, u32 sw_if_index)
 156 {
 157   snat_session_key_t key0;
 158   clib_bihash_kv_8_8_t kv0, value0;
 159   snat_interface_t *i;
 160
 161   /* src NAT check */
 162   key0.addr = ip0->src_address;
 163   key0.port = src_port;
 164   key0.protocol = proto0;
 165   key0.fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 166   kv0.key = key0.as_u64;
 167
 168   if (!clib_bihash_search_8_8
 169       (&sm->per_thread_data[thread_index].out2in, &kv0, &value0))
 170     return 1;
 171
 172   /* dst NAT check */
 173   key0.addr = ip0->dst_address;
 174   key0.port = dst_port;
 175   key0.protocol = proto0;
 176   kv0.key = key0.as_u64;
 177   if (!clib_bihash_search_8_8
 178       (&sm->per_thread_data[thread_index].in2out, &kv0, &value0))
 179     {
 180       /* hairpinning */
 181     /* *INDENT-OFF* */
 182     pool_foreach (i, sm->output_feature_interfaces,
 183     ({
 184       if ((nat_interface_is_inside(i)) && (sw_if_index == i->sw_if_index))
 185         return 0;
 186     }));
 187     /* *INDENT-ON* */
 188       return 1;
 189     }
 190
 191   return 0;
 192 }
 193
 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_log_warn ("out2in key del failed");
 212
 213       snat_ipfix_logging_nat44_ses_delete (s->in2out.addr.as_u32,
 214                                            s->out2in.addr.as_u32,
 215                                            s->in2out.protocol,
 216                                            s->in2out.port,
 217                                            s->out2in.port,
 218                                            s->in2out.fib_index);
 219
 220       nat_syslog_nat44_apmdel (s->user_index, s->in2out.fib_index,
 221                                &s->in2out.addr, s->in2out.port,
 222                                &s->out2in.addr, s->out2in.port,
 223                                s->in2out.protocol);
 224
 225       if (!snat_is_session_static (s))
 226         snat_free_outside_address_and_port (sm->addresses, ctx->thread_index,
 227                                             &s->out2in);
 228
 229       nat44_delete_session (sm, s, ctx->thread_index);
 230       return 1;
 231     }
 232
 233   return 0;
 234 }
 235
 236 static u32
 237 slow_path (snat_main_t * sm, vlib_buffer_t * b0,
 238            ip4_header_t * ip0,
 239            u32 rx_fib_index0,
 240            snat_session_key_t * key0,
 241            snat_session_t ** sessionp,
 242            vlib_node_runtime_t * node, u32 next0, u32 thread_index, f64 now)
 243 {
 244   snat_user_t *u;
 245   snat_session_t *s = 0;
 246   clib_bihash_kv_8_8_t kv0;
 247   snat_session_key_t key1;
 248   udp_header_t *udp0 = ip4_next_header (ip0);
 249   u8 is_sm = 0;
 250   nat_outside_fib_t *outside_fib;
 251   fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
 252   u8 identity_nat;
 253   fib_prefix_t pfx = {
 254     .fp_proto = FIB_PROTOCOL_IP4,
 255     .fp_len = 32,
 256     .fp_addr = {
 257                 .ip4.as_u32 = ip0->dst_address.as_u32,
 258                 },
 259   };
 260   nat44_is_idle_session_ctx_t ctx0;
 261
 262   if (PREDICT_FALSE (maximum_sessions_exceeded (sm, thread_index)))
 263     {
 264       b0->error = node->errors[SNAT_IN2OUT_ERROR_MAX_SESSIONS_EXCEEDED];
 265       nat_ipfix_logging_max_sessions (sm->max_translations);
 266       nat_log_notice ("maximum sessions exceeded");
 267       return SNAT_IN2OUT_NEXT_DROP;
 268     }
 269
 270   key1.protocol = key0->protocol;
 271
 272   /* First try to match static mapping by local address and port */
 273   if (snat_static_mapping_match
 274       (sm, *key0, &key1, 0, 0, 0, 0, 0, &identity_nat))
 275     {
 276       /* Try to create dynamic translation */
 277       if (snat_alloc_outside_address_and_port (sm->addresses, rx_fib_index0,
 278                                                thread_index, &key1,
 279                                                sm->port_per_thread,
 280                                                sm->per_thread_data
 281                                                [thread_index].snat_thread_index))
 282         {
 283           b0->error = node->errors[SNAT_IN2OUT_ERROR_OUT_OF_PORTS];
 284           return SNAT_IN2OUT_NEXT_DROP;
 285         }
 286     }
 287   else
 288     {
 289       if (PREDICT_FALSE (identity_nat))
 290         {
 291           *sessionp = s;
 292           return next0;
 293         }
 294
 295       is_sm = 1;
 296     }
 297
 298   u = nat_user_get_or_create (sm, &ip0->src_address, rx_fib_index0,
 299                               thread_index);
 300   if (!u)
 301     {
 302       nat_log_warn ("create NAT user failed");
 303       return SNAT_IN2OUT_NEXT_DROP;
 304     }
 305
 306   s = nat_session_alloc_or_recycle (sm, u, thread_index);
 307   if (!s)
 308     {
 309       nat44_delete_user_with_no_session (sm, u, thread_index);
 310       nat_log_warn ("create NAT session failed");
 311       return SNAT_IN2OUT_NEXT_DROP;
 312     }
 313
 314   if (is_sm)
 315     s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 316   user_session_increment (sm, u, is_sm);
 317   s->in2out = *key0;
 318   s->out2in = key1;
 319   s->out2in.protocol = key0->protocol;
 320   s->out2in.fib_index = sm->outside_fib_index;
 321   switch (vec_len (sm->outside_fibs))
 322     {
 323     case 0:
 324       s->out2in.fib_index = sm->outside_fib_index;
 325       break;
 326     case 1:
 327       s->out2in.fib_index = sm->outside_fibs[0].fib_index;
 328       break;
 329     default:
 330       /* *INDENT-OFF* */
 331       vec_foreach (outside_fib, sm->outside_fibs)
 332         {
 333           fei = fib_table_lookup (outside_fib->fib_index, &pfx);
 334           if (FIB_NODE_INDEX_INVALID != fei)
 335             {
 336               if (fib_entry_get_resolving_interface (fei) != ~0)
 337                 {
 338                   s->out2in.fib_index = outside_fib->fib_index;
 339                   break;
 340                 }
 341             }
 342         }
 343       /* *INDENT-ON* */
 344       break;
 345     }
 346   s->ext_host_addr.as_u32 = ip0->dst_address.as_u32;
 347   s->ext_host_port = udp0->dst_port;
 348   *sessionp = s;
 349
 350   /* Add to translation hashes */
 351   ctx0.now = now;
 352   ctx0.thread_index = thread_index;
 353   kv0.key = s->in2out.as_u64;
 354   kv0.value = s - sm->per_thread_data[thread_index].sessions;
 355   if (clib_bihash_add_or_overwrite_stale_8_8
 356       (&sm->per_thread_data[thread_index].in2out, &kv0,
 357        nat44_i2o_is_idle_session_cb, &ctx0))
 358     nat_log_notice ("in2out key add failed");
 359
 360   kv0.key = s->out2in.as_u64;
 361   kv0.value = s - sm->per_thread_data[thread_index].sessions;
 362
 363   if (clib_bihash_add_or_overwrite_stale_8_8
 364       (&sm->per_thread_data[thread_index].out2in, &kv0,
 365        nat44_o2i_is_idle_session_cb, &ctx0))
 366     nat_log_notice ("out2in key add failed");
 367
 368   /* log NAT event */
 369   snat_ipfix_logging_nat44_ses_create (s->in2out.addr.as_u32,
 370                                        s->out2in.addr.as_u32,
 371                                        s->in2out.protocol,
 372                                        s->in2out.port,
 373                                        s->out2in.port, s->in2out.fib_index);
 374
 375   nat_syslog_nat44_apmadd (s->user_index, s->in2out.fib_index,
 376                            &s->in2out.addr, s->in2out.port, &s->out2in.addr,
 377                            s->out2in.port, s->in2out.protocol);
 378
 379   return next0;
 380 }
 381
 382 static_always_inline
 383   snat_in2out_error_t icmp_get_key (ip4_header_t * ip0,
 384                                     snat_session_key_t * p_key0)
 385 {
 386   icmp46_header_t *icmp0;
 387   snat_session_key_t key0;
 388   icmp_echo_header_t *echo0, *inner_echo0 = 0;
 389   ip4_header_t *inner_ip0 = 0;
 390   void *l4_header = 0;
 391   icmp46_header_t *inner_icmp0;
 392
 393   icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
 394   echo0 = (icmp_echo_header_t *) (icmp0 + 1);
 395
 396   if (!icmp_is_error_message (icmp0))
 397     {
 398       key0.protocol = SNAT_PROTOCOL_ICMP;
 399       key0.addr = ip0->src_address;
 400       key0.port = echo0->identifier;
 401     }
 402   else
 403     {
 404       inner_ip0 = (ip4_header_t *) (echo0 + 1);
 405       l4_header = ip4_next_header (inner_ip0);
 406       key0.protocol = ip_proto_to_snat_proto (inner_ip0->protocol);
 407       key0.addr = inner_ip0->dst_address;
 408       switch (key0.protocol)
 409         {
 410         case SNAT_PROTOCOL_ICMP:
 411           inner_icmp0 = (icmp46_header_t *) l4_header;
 412           inner_echo0 = (icmp_echo_header_t *) (inner_icmp0 + 1);
 413           key0.port = inner_echo0->identifier;
 414           break;
 415         case SNAT_PROTOCOL_UDP:
 416         case SNAT_PROTOCOL_TCP:
 417           key0.port = ((tcp_udp_header_t *) l4_header)->dst_port;
 418           break;
 419         default:
 420           return SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL;
 421         }
 422     }
 423   *p_key0 = key0;
 424   return -1;                    /* success */
 425 }
 426
 427 /**
 428  * Get address and port values to be used for ICMP packet translation
 429  * and create session if needed
 430  *
 431  * @param[in,out] sm             NAT main
 432  * @param[in,out] node           NAT node runtime
 433  * @param[in] thread_index       thread index
 434  * @param[in,out] b0             buffer containing packet to be translated
 435  * @param[out] p_proto           protocol used for matching
 436  * @param[out] p_value           address and port after NAT translation
 437  * @param[out] p_dont_translate  if packet should not be translated
 438  * @param d                      optional parameter
 439  * @param e                      optional parameter
 440  */
 441 u32
 442 icmp_match_in2out_slow (snat_main_t * sm, vlib_node_runtime_t * node,
 443                         u32 thread_index, vlib_buffer_t * b0,
 444                         ip4_header_t * ip0, u8 * p_proto,
 445                         snat_session_key_t * p_value,
 446                         u8 * p_dont_translate, void *d, void *e)
 447 {
 448   icmp46_header_t *icmp0;
 449   u32 sw_if_index0;
 450   u32 rx_fib_index0;
 451   snat_session_key_t key0;
 452   snat_session_t *s0 = 0;
 453   u8 dont_translate = 0;
 454   clib_bihash_kv_8_8_t kv0, value0;
 455   u32 next0 = ~0;
 456   int err;
 457
 458   icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
 459   sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 460   rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
 461
 462   err = icmp_get_key (ip0, &key0);
 463   if (err != -1)
 464     {
 465       b0->error = node->errors[err];
 466       next0 = SNAT_IN2OUT_NEXT_DROP;
 467       goto out;
 468     }
 469   key0.fib_index = rx_fib_index0;
 470
 471   kv0.key = key0.as_u64;
 472
 473   if (clib_bihash_search_8_8 (&sm->per_thread_data[thread_index].in2out, &kv0,
 474                               &value0))
 475     {
 476       if (vnet_buffer (b0)->sw_if_index[VLIB_TX] != ~0)
 477         {
 478           if (PREDICT_FALSE (nat_not_translate_output_feature (sm, ip0,
 479                                                                key0.protocol,
 480                                                                key0.port,
 481                                                                key0.port,
 482                                                                thread_index,
 483                                                                sw_if_index0)))
 484             {
 485               dont_translate = 1;
 486               goto out;
 487             }
 488         }
 489       else
 490         {
 491           if (PREDICT_FALSE (snat_not_translate (sm, node, sw_if_index0,
 492                                                  ip0, SNAT_PROTOCOL_ICMP,
 493                                                  rx_fib_index0,
 494                                                  thread_index)))
 495             {
 496               dont_translate = 1;
 497               goto out;
 498             }
 499         }
 500
 501       if (PREDICT_FALSE (icmp_is_error_message (icmp0)))
 502         {
 503           b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
 504           next0 = SNAT_IN2OUT_NEXT_DROP;
 505           goto out;
 506         }
 507
 508       next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0, &s0, node, next0,
 509                          thread_index, vlib_time_now (sm->vlib_main));
 510
 511       if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
 512         goto out;
 513
 514       if (!s0)
 515         {
 516           dont_translate = 1;
 517           goto out;
 518         }
 519     }
 520   else
 521     {
 522       if (PREDICT_FALSE (icmp0->type != ICMP4_echo_request &&
 523                          icmp0->type != ICMP4_echo_reply &&
 524                          !icmp_is_error_message (icmp0)))
 525         {
 526           b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
 527           next0 = SNAT_IN2OUT_NEXT_DROP;
 528           goto out;
 529         }
 530
 531       s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
 532                               value0.value);
 533     }
 534
 535 out:
 536   *p_proto = key0.protocol;
 537   if (s0)
 538     *p_value = s0->out2in;
 539   *p_dont_translate = dont_translate;
 540   if (d)
 541     *(snat_session_t **) d = s0;
 542   return next0;
 543 }
 544
 545 /**
 546  * Get address and port values to be used for ICMP packet translation
 547  *
 548  * @param[in] sm                 NAT main
 549  * @param[in,out] node           NAT node runtime
 550  * @param[in] thread_index       thread index
 551  * @param[in,out] b0             buffer containing packet to be translated
 552  * @param[out] p_proto           protocol used for matching
 553  * @param[out] p_value           address and port after NAT translation
 554  * @param[out] p_dont_translate  if packet should not be translated
 555  * @param d                      optional parameter
 556  * @param e                      optional parameter
 557  */
 558 u32
 559 icmp_match_in2out_fast (snat_main_t * sm, vlib_node_runtime_t * node,
 560                         u32 thread_index, vlib_buffer_t * b0,
 561                         ip4_header_t * ip0, u8 * p_proto,
 562                         snat_session_key_t * p_value,
 563                         u8 * p_dont_translate, void *d, void *e)
 564 {
 565   icmp46_header_t *icmp0;
 566   u32 sw_if_index0;
 567   u32 rx_fib_index0;
 568   snat_session_key_t key0;
 569   snat_session_key_t sm0;
 570   u8 dont_translate = 0;
 571   u8 is_addr_only;
 572   u32 next0 = ~0;
 573   int err;
 574
 575   icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
 576   sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 577   rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
 578
 579   err = icmp_get_key (ip0, &key0);
 580   if (err != -1)
 581     {
 582       b0->error = node->errors[err];
 583       next0 = SNAT_IN2OUT_NEXT_DROP;
 584       goto out2;
 585     }
 586   key0.fib_index = rx_fib_index0;
 587
 588   if (snat_static_mapping_match
 589       (sm, key0, &sm0, 0, &is_addr_only, 0, 0, 0, 0))
 590     {
 591       if (PREDICT_FALSE (snat_not_translate_fast (sm, node, sw_if_index0, ip0,
 592                                                   IP_PROTOCOL_ICMP,
 593                                                   rx_fib_index0)))
 594         {
 595           dont_translate = 1;
 596           goto out;
 597         }
 598
 599       if (icmp_is_error_message (icmp0))
 600         {
 601           next0 = SNAT_IN2OUT_NEXT_DROP;
 602           goto out;
 603         }
 604
 605       b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
 606       next0 = SNAT_IN2OUT_NEXT_DROP;
 607       goto out;
 608     }
 609
 610   if (PREDICT_FALSE (icmp0->type != ICMP4_echo_request &&
 611                      (icmp0->type != ICMP4_echo_reply || !is_addr_only) &&
 612                      !icmp_is_error_message (icmp0)))
 613     {
 614       b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
 615       next0 = SNAT_IN2OUT_NEXT_DROP;
 616       goto out;
 617     }
 618
 619 out:
 620   *p_value = sm0;
 621 out2:
 622   *p_proto = key0.protocol;
 623   *p_dont_translate = dont_translate;
 624   return next0;
 625 }
 626
 627 u32
 628 icmp_in2out (snat_main_t * sm,
 629              vlib_buffer_t * b0,
 630              ip4_header_t * ip0,
 631              icmp46_header_t * icmp0,
 632              u32 sw_if_index0,
 633              u32 rx_fib_index0,
 634              vlib_node_runtime_t * node,
 635              u32 next0, u32 thread_index, void *d, void *e)
 636 {
 637   snat_session_key_t sm0;
 638   u8 protocol;
 639   icmp_echo_header_t *echo0, *inner_echo0 = 0;
 640   ip4_header_t *inner_ip0;
 641   void *l4_header = 0;
 642   icmp46_header_t *inner_icmp0;
 643   u8 dont_translate;
 644   u32 new_addr0, old_addr0;
 645   u16 old_id0, new_id0;
 646   u16 old_checksum0, new_checksum0;
 647   ip_csum_t sum0;
 648   u16 checksum0;
 649   u32 next0_tmp;
 650
 651   echo0 = (icmp_echo_header_t *) (icmp0 + 1);
 652
 653   next0_tmp = sm->icmp_match_in2out_cb (sm, node, thread_index, b0, ip0,
 654                                         &protocol, &sm0, &dont_translate, d,
 655                                         e);
 656   if (next0_tmp != ~0)
 657     next0 = next0_tmp;
 658   if (next0 == SNAT_IN2OUT_NEXT_DROP || dont_translate)
 659     goto out;
 660
 661   if (PREDICT_TRUE (!ip4_is_fragment (ip0)))
 662     {
 663       sum0 = ip_incremental_checksum_buffer (sm->vlib_main, b0, (u8 *) icmp0 -
 664                                              (u8 *)
 665                                              vlib_buffer_get_current (b0),
 666                                              ntohs (ip0->length) -
 667                                              ip4_header_bytes (ip0), 0);
 668       checksum0 = ~ip_csum_fold (sum0);
 669       if (PREDICT_FALSE (checksum0 != 0 && checksum0 != 0xffff))
 670         {
 671           next0 = SNAT_IN2OUT_NEXT_DROP;
 672           goto out;
 673         }
 674     }
 675
 676   old_addr0 = ip0->src_address.as_u32;
 677   new_addr0 = ip0->src_address.as_u32 = sm0.addr.as_u32;
 678
 679   sum0 = ip0->checksum;
 680   sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 681                          src_address /* changed member */ );
 682   ip0->checksum = ip_csum_fold (sum0);
 683
 684   if (icmp0->checksum == 0)
 685     icmp0->checksum = 0xffff;
 686
 687   if (!icmp_is_error_message (icmp0))
 688     {
 689       new_id0 = sm0.port;
 690       if (PREDICT_FALSE (new_id0 != echo0->identifier))
 691         {
 692           old_id0 = echo0->identifier;
 693           new_id0 = sm0.port;
 694           echo0->identifier = new_id0;
 695
 696           sum0 = icmp0->checksum;
 697           sum0 = ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
 698                                  identifier);
 699           icmp0->checksum = ip_csum_fold (sum0);
 700         }
 701     }
 702   else
 703     {
 704       inner_ip0 = (ip4_header_t *) (echo0 + 1);
 705       l4_header = ip4_next_header (inner_ip0);
 706
 707       if (!ip4_header_checksum_is_valid (inner_ip0))
 708         {
 709           next0 = SNAT_IN2OUT_NEXT_DROP;
 710           goto out;
 711         }
 712
 713       /* update inner destination IP address */
 714       old_addr0 = inner_ip0->dst_address.as_u32;
 715       inner_ip0->dst_address = sm0.addr;
 716       new_addr0 = inner_ip0->dst_address.as_u32;
 717       sum0 = icmp0->checksum;
 718       sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 719                              dst_address /* changed member */ );
 720       icmp0->checksum = ip_csum_fold (sum0);
 721
 722       /* update inner IP header checksum */
 723       old_checksum0 = inner_ip0->checksum;
 724       sum0 = inner_ip0->checksum;
 725       sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 726                              dst_address /* changed member */ );
 727       inner_ip0->checksum = ip_csum_fold (sum0);
 728       new_checksum0 = inner_ip0->checksum;
 729       sum0 = icmp0->checksum;
 730       sum0 = ip_csum_update (sum0, old_checksum0, new_checksum0, ip4_header_t,
 731                              checksum);
 732       icmp0->checksum = ip_csum_fold (sum0);
 733
 734       switch (protocol)
 735         {
 736         case SNAT_PROTOCOL_ICMP:
 737           inner_icmp0 = (icmp46_header_t *) l4_header;
 738           inner_echo0 = (icmp_echo_header_t *) (inner_icmp0 + 1);
 739
 740           old_id0 = inner_echo0->identifier;
 741           new_id0 = sm0.port;
 742           inner_echo0->identifier = new_id0;
 743
 744           sum0 = icmp0->checksum;
 745           sum0 = ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
 746                                  identifier);
 747           icmp0->checksum = ip_csum_fold (sum0);
 748           break;
 749         case SNAT_PROTOCOL_UDP:
 750         case SNAT_PROTOCOL_TCP:
 751           old_id0 = ((tcp_udp_header_t *) l4_header)->dst_port;
 752           new_id0 = sm0.port;
 753           ((tcp_udp_header_t *) l4_header)->dst_port = new_id0;
 754
 755           sum0 = icmp0->checksum;
 756           sum0 = ip_csum_update (sum0, old_id0, new_id0, tcp_udp_header_t,
 757                                  dst_port);
 758           icmp0->checksum = ip_csum_fold (sum0);
 759           break;
 760         default:
 761           ASSERT (0);
 762         }
 763     }
 764
 765   if (vnet_buffer (b0)->sw_if_index[VLIB_TX] == ~0)
 766     {
 767       if (sm->deterministic ||
 768           0 != snat_icmp_hairpinning (sm, b0, ip0, icmp0,
 769                                       sm->endpoint_dependent))
 770         vnet_buffer (b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
 771     }
 772
 773 out:
 774   return next0;
 775 }
 776
 777 static inline u32
 778 icmp_in2out_slow_path (snat_main_t * sm,
 779                        vlib_buffer_t * b0,
 780                        ip4_header_t * ip0,
 781                        icmp46_header_t * icmp0,
 782                        u32 sw_if_index0,
 783                        u32 rx_fib_index0,
 784                        vlib_node_runtime_t * node,
 785                        u32 next0,
 786                        f64 now, u32 thread_index, snat_session_t ** p_s0)
 787 {
 788   next0 = icmp_in2out (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
 789                        next0, thread_index, p_s0, 0);
 790   snat_session_t *s0 = *p_s0;
 791   if (PREDICT_TRUE (next0 != SNAT_IN2OUT_NEXT_DROP && s0))
 792     {
 793       /* Accounting */
 794       nat44_session_update_counters (s0, now,
 795                                      vlib_buffer_length_in_chain
 796                                      (sm->vlib_main, b0));
 797       /* Per-user LRU list maintenance */
 798       nat44_session_update_lru (sm, s0, thread_index);
 799     }
 800   return next0;
 801 }
 802
 803 static int
 804 nat_in2out_sm_unknown_proto (snat_main_t * sm,
 805                              vlib_buffer_t * b,
 806                              ip4_header_t * ip, u32 rx_fib_index)
 807 {
 808   clib_bihash_kv_8_8_t kv, value;
 809   snat_static_mapping_t *m;
 810   snat_session_key_t m_key;
 811   u32 old_addr, new_addr;
 812   ip_csum_t sum;
 813
 814   m_key.addr = ip->src_address;
 815   m_key.port = 0;
 816   m_key.protocol = 0;
 817   m_key.fib_index = rx_fib_index;
 818   kv.key = m_key.as_u64;
 819   if (clib_bihash_search_8_8 (&sm->static_mapping_by_local, &kv, &value))
 820     return 1;
 821
 822   m = pool_elt_at_index (sm->static_mappings, value.value);
 823
 824   old_addr = ip->src_address.as_u32;
 825   new_addr = ip->src_address.as_u32 = m->external_addr.as_u32;
 826   sum = ip->checksum;
 827   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, src_address);
 828   ip->checksum = ip_csum_fold (sum);
 829
 830
 831   /* Hairpinning */
 832   if (vnet_buffer (b)->sw_if_index[VLIB_TX] == ~0)
 833     {
 834       vnet_buffer (b)->sw_if_index[VLIB_TX] = m->fib_index;
 835       nat_hairpinning_sm_unknown_proto (sm, b, ip);
 836     }
 837
 838   return 0;
 839 }
 840
 841 static inline uword
 842 snat_in2out_node_fn_inline (vlib_main_t * vm,
 843                             vlib_node_runtime_t * node,
 844                             vlib_frame_t * frame, int is_slow_path,
 845                             int is_output_feature)
 846 {
 847   u32 n_left_from, *from, *to_next;
 848   snat_in2out_next_t next_index;
 849   u32 pkts_processed = 0;
 850   snat_main_t *sm = &snat_main;
 851   f64 now = vlib_time_now (vm);
 852   u32 stats_node_index;
 853   u32 thread_index = vm->thread_index;
 854
 855   stats_node_index = is_slow_path ? snat_in2out_slowpath_node.index :
 856     snat_in2out_node.index;
 857
 858   from = vlib_frame_vector_args (frame);
 859   n_left_from = frame->n_vectors;
 860   next_index = node->cached_next_index;
 861
 862   while (n_left_from > 0)
 863     {
 864       u32 n_left_to_next;
 865
 866       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 867
 868       while (n_left_from >= 4 && n_left_to_next >= 2)
 869         {
 870           u32 bi0, bi1;
 871           vlib_buffer_t *b0, *b1;
 872           u32 next0, next1;
 873           u32 sw_if_index0, sw_if_index1;
 874           ip4_header_t *ip0, *ip1;
 875           ip_csum_t sum0, sum1;
 876           u32 new_addr0, old_addr0, new_addr1, old_addr1;
 877           u16 old_port0, new_port0, old_port1, new_port1;
 878           udp_header_t *udp0, *udp1;
 879           tcp_header_t *tcp0, *tcp1;
 880           icmp46_header_t *icmp0, *icmp1;
 881           snat_session_key_t key0, key1;
 882           u32 rx_fib_index0, rx_fib_index1;
 883           u32 proto0, proto1;
 884           snat_session_t *s0 = 0, *s1 = 0;
 885           clib_bihash_kv_8_8_t kv0, value0, kv1, value1;
 886           u32 iph_offset0 = 0, iph_offset1 = 0;
 887
 888           /* Prefetch next iteration. */
 889           {
 890             vlib_buffer_t *p2, *p3;
 891
 892             p2 = vlib_get_buffer (vm, from[2]);
 893             p3 = vlib_get_buffer (vm, from[3]);
 894
 895             vlib_prefetch_buffer_header (p2, LOAD);
 896             vlib_prefetch_buffer_header (p3, LOAD);
 897
 898             CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE);
 899             CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE);
 900           }
 901
 902           /* speculatively enqueue b0 and b1 to the current next frame */
 903           to_next[0] = bi0 = from[0];
 904           to_next[1] = bi1 = from[1];
 905           from += 2;
 906           to_next += 2;
 907           n_left_from -= 2;
 908           n_left_to_next -= 2;
 909
 910           b0 = vlib_get_buffer (vm, bi0);
 911           b1 = vlib_get_buffer (vm, bi1);
 912
 913           if (is_output_feature)
 914             iph_offset0 = vnet_buffer (b0)->ip.save_rewrite_length;
 915
 916           ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
 917                                   iph_offset0);
 918
 919           udp0 = ip4_next_header (ip0);
 920           tcp0 = (tcp_header_t *) udp0;
 921           icmp0 = (icmp46_header_t *) udp0;
 922
 923           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 924           rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
 925                                    sw_if_index0);
 926
 927           next0 = next1 = SNAT_IN2OUT_NEXT_LOOKUP;
 928
 929           if (PREDICT_FALSE (ip0->ttl == 1))
 930             {
 931               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 932               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
 933                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
 934                                            0);
 935               next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
 936               goto trace00;
 937             }
 938
 939           proto0 = ip_proto_to_snat_proto (ip0->protocol);
 940
 941           /* Next configured feature, probably ip4-lookup */
 942           if (is_slow_path)
 943             {
 944               if (PREDICT_FALSE (proto0 == ~0))
 945                 {
 946                   if (nat_in2out_sm_unknown_proto
 947                       (sm, b0, ip0, rx_fib_index0))
 948                     {
 949                       next0 = SNAT_IN2OUT_NEXT_DROP;
 950                       b0->error =
 951                         node->errors[SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL];
 952                     }
 953                   goto trace00;
 954                 }
 955
 956               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
 957                 {
 958                   next0 = icmp_in2out_slow_path
 959                     (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0,
 960                      node, next0, now, thread_index, &s0);
 961                   goto trace00;
 962                 }
 963             }
 964           else
 965             {
 966               if (PREDICT_FALSE (proto0 == ~0))
 967                 {
 968                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
 969                   goto trace00;
 970                 }
 971
 972               if (ip4_is_fragment (ip0))
 973                 {
 974                   next0 = SNAT_IN2OUT_NEXT_REASS;
 975                   goto trace00;
 976                 }
 977
 978               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
 979                 {
 980                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
 981                   goto trace00;
 982                 }
 983             }
 984
 985           key0.addr = ip0->src_address;
 986           key0.port = udp0->src_port;
 987           key0.protocol = proto0;
 988           key0.fib_index = rx_fib_index0;
 989
 990           kv0.key = key0.as_u64;
 991
 992           if (PREDICT_FALSE
 993               (clib_bihash_search_8_8
 994                (&sm->per_thread_data[thread_index].in2out, &kv0,
 995                 &value0) != 0))
 996             {
 997               if (is_slow_path)
 998                 {
 999                   if (is_output_feature)
1000                     {
1001                       if (PREDICT_FALSE (nat_not_translate_output_feature (sm,
1002                                                                            ip0,
1003                                                                            proto0,
1004                                                                            udp0->src_port,
1005                                                                            udp0->dst_port,
1006                                                                            thread_index,
1007                                                                            sw_if_index0)))
1008                         goto trace00;
1009                     }
1010                   else
1011                     {
1012                       if (PREDICT_FALSE
1013                           (snat_not_translate
1014                            (sm, node, sw_if_index0, ip0, proto0,
1015                             rx_fib_index0, thread_index)))
1016                         goto trace00;
1017                     }
1018
1019                   next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0,
1020                                      &s0, node, next0, thread_index, now);
1021                   if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
1022                     goto trace00;
1023
1024                   if (PREDICT_FALSE (!s0))
1025                     goto trace00;
1026                 }
1027               else
1028                 {
1029                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1030                   goto trace00;
1031                 }
1032             }
1033           else
1034             s0 =
1035               pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
1036                                  value0.value);
1037
1038           b0->flags |= VNET_BUFFER_F_IS_NATED;
1039
1040           old_addr0 = ip0->src_address.as_u32;
1041           ip0->src_address = s0->out2in.addr;
1042           new_addr0 = ip0->src_address.as_u32;
1043           if (!is_output_feature)
1044             vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
1045
1046           sum0 = ip0->checksum;
1047           sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1048                                  ip4_header_t,
1049                                  src_address /* changed member */ );
1050           ip0->checksum = ip_csum_fold (sum0);
1051
1052           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
1053             {
1054               old_port0 = tcp0->src_port;
1055               tcp0->src_port = s0->out2in.port;
1056               new_port0 = tcp0->src_port;
1057
1058               sum0 = tcp0->checksum;
1059               sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1060                                      ip4_header_t,
1061                                      dst_address /* changed member */ );
1062               sum0 = ip_csum_update (sum0, old_port0, new_port0,
1063                                      ip4_header_t /* cheat */ ,
1064                                      length /* changed member */ );
1065               mss_clamping (sm, tcp0, &sum0);
1066               tcp0->checksum = ip_csum_fold (sum0);
1067             }
1068           else
1069             {
1070               old_port0 = udp0->src_port;
1071               udp0->src_port = s0->out2in.port;
1072               udp0->checksum = 0;
1073             }
1074
1075           /* Accounting */
1076           nat44_session_update_counters (s0, now,
1077                                          vlib_buffer_length_in_chain (vm,
1078                                                                       b0));
1079           /* Per-user LRU list maintenance */
1080           nat44_session_update_lru (sm, s0, thread_index);
1081         trace00:
1082
1083           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1084                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1085             {
1086               snat_in2out_trace_t *t =
1087                 vlib_add_trace (vm, node, b0, sizeof (*t));
1088               t->is_slow_path = is_slow_path;
1089               t->sw_if_index = sw_if_index0;
1090               t->next_index = next0;
1091               t->session_index = ~0;
1092               if (s0)
1093                 t->session_index =
1094                   s0 - sm->per_thread_data[thread_index].sessions;
1095             }
1096
1097           pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
1098
1099           if (is_output_feature)
1100             iph_offset1 = vnet_buffer (b1)->ip.save_rewrite_length;
1101
1102           ip1 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b1) +
1103                                   iph_offset1);
1104
1105           udp1 = ip4_next_header (ip1);
1106           tcp1 = (tcp_header_t *) udp1;
1107           icmp1 = (icmp46_header_t *) udp1;
1108
1109           sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];
1110           rx_fib_index1 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
1111                                    sw_if_index1);
1112
1113           if (PREDICT_FALSE (ip1->ttl == 1))
1114             {
1115               vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1116               icmp4_error_set_vnet_buffer (b1, ICMP4_time_exceeded,
1117                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1118                                            0);
1119               next1 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
1120               goto trace01;
1121             }
1122
1123           proto1 = ip_proto_to_snat_proto (ip1->protocol);
1124
1125           /* Next configured feature, probably ip4-lookup */
1126           if (is_slow_path)
1127             {
1128               if (PREDICT_FALSE (proto1 == ~0))
1129                 {
1130                   if (nat_in2out_sm_unknown_proto
1131                       (sm, b1, ip1, rx_fib_index1))
1132                     {
1133                       next1 = SNAT_IN2OUT_NEXT_DROP;
1134                       b1->error =
1135                         node->errors[SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL];
1136                     }
1137                   goto trace01;
1138                 }
1139
1140               if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP))
1141                 {
1142                   next1 = icmp_in2out_slow_path
1143                     (sm, b1, ip1, icmp1, sw_if_index1, rx_fib_index1, node,
1144                      next1, now, thread_index, &s1);
1145                   goto trace01;
1146                 }
1147             }
1148           else
1149             {
1150               if (PREDICT_FALSE (proto1 == ~0))
1151                 {
1152                   next1 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1153                   goto trace01;
1154                 }
1155
1156               if (ip4_is_fragment (ip1))
1157                 {
1158                   next1 = SNAT_IN2OUT_NEXT_REASS;
1159                   goto trace01;
1160                 }
1161
1162               if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP))
1163                 {
1164                   next1 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1165                   goto trace01;
1166                 }
1167             }
1168
1169           key1.addr = ip1->src_address;
1170           key1.port = udp1->src_port;
1171           key1.protocol = proto1;
1172           key1.fib_index = rx_fib_index1;
1173
1174           kv1.key = key1.as_u64;
1175
1176           if (PREDICT_FALSE
1177               (clib_bihash_search_8_8
1178                (&sm->per_thread_data[thread_index].in2out, &kv1,
1179                 &value1) != 0))
1180             {
1181               if (is_slow_path)
1182                 {
1183                   if (is_output_feature)
1184                     {
1185                       if (PREDICT_FALSE (nat_not_translate_output_feature (sm,
1186                                                                            ip1,
1187                                                                            proto1,
1188                                                                            udp1->src_port,
1189                                                                            udp1->dst_port,
1190                                                                            thread_index,
1191                                                                            sw_if_index1)))
1192                         goto trace01;
1193                     }
1194                   else
1195                     {
1196                       if (PREDICT_FALSE
1197                           (snat_not_translate
1198                            (sm, node, sw_if_index1, ip1, proto1,
1199                             rx_fib_index1, thread_index)))
1200                         goto trace01;
1201                     }
1202
1203                   next1 = slow_path (sm, b1, ip1, rx_fib_index1, &key1,
1204                                      &s1, node, next1, thread_index, now);
1205                   if (PREDICT_FALSE (next1 == SNAT_IN2OUT_NEXT_DROP))
1206                     goto trace01;
1207
1208                   if (PREDICT_FALSE (!s1))
1209                     goto trace01;
1210                 }
1211               else
1212                 {
1213                   next1 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1214                   goto trace01;
1215                 }
1216             }
1217           else
1218             s1 =
1219               pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
1220                                  value1.value);
1221
1222           b1->flags |= VNET_BUFFER_F_IS_NATED;
1223
1224           old_addr1 = ip1->src_address.as_u32;
1225           ip1->src_address = s1->out2in.addr;
1226           new_addr1 = ip1->src_address.as_u32;
1227           if (!is_output_feature)
1228             vnet_buffer (b1)->sw_if_index[VLIB_TX] = s1->out2in.fib_index;
1229
1230           sum1 = ip1->checksum;
1231           sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
1232                                  ip4_header_t,
1233                                  src_address /* changed member */ );
1234           ip1->checksum = ip_csum_fold (sum1);
1235
1236           if (PREDICT_TRUE (proto1 == SNAT_PROTOCOL_TCP))
1237             {
1238               old_port1 = tcp1->src_port;
1239               tcp1->src_port = s1->out2in.port;
1240               new_port1 = tcp1->src_port;
1241
1242               sum1 = tcp1->checksum;
1243               sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
1244                                      ip4_header_t,
1245                                      dst_address /* changed member */ );
1246               sum1 = ip_csum_update (sum1, old_port1, new_port1,
1247                                      ip4_header_t /* cheat */ ,
1248                                      length /* changed member */ );
1249               mss_clamping (sm, tcp1, &sum1);
1250               tcp1->checksum = ip_csum_fold (sum1);
1251             }
1252           else
1253             {
1254               old_port1 = udp1->src_port;
1255               udp1->src_port = s1->out2in.port;
1256               udp1->checksum = 0;
1257             }
1258
1259           /* Accounting */
1260           nat44_session_update_counters (s1, now,
1261                                          vlib_buffer_length_in_chain (vm,
1262                                                                       b1));
1263           /* Per-user LRU list maintenance */
1264           nat44_session_update_lru (sm, s1, thread_index);
1265         trace01:
1266
1267           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1268                              && (b1->flags & VLIB_BUFFER_IS_TRACED)))
1269             {
1270               snat_in2out_trace_t *t =
1271                 vlib_add_trace (vm, node, b1, sizeof (*t));
1272               t->sw_if_index = sw_if_index1;
1273               t->next_index = next1;
1274               t->session_index = ~0;
1275               if (s1)
1276                 t->session_index =
1277                   s1 - sm->per_thread_data[thread_index].sessions;
1278             }
1279
1280           pkts_processed += next1 != SNAT_IN2OUT_NEXT_DROP;
1281
1282           /* verify speculative enqueues, maybe switch current next frame */
1283           vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
1284                                            to_next, n_left_to_next,
1285                                            bi0, bi1, next0, next1);
1286         }
1287
1288       while (n_left_from > 0 && n_left_to_next > 0)
1289         {
1290           u32 bi0;
1291           vlib_buffer_t *b0;
1292           u32 next0;
1293           u32 sw_if_index0;
1294           ip4_header_t *ip0;
1295           ip_csum_t sum0;
1296           u32 new_addr0, old_addr0;
1297           u16 old_port0, new_port0;
1298           udp_header_t *udp0;
1299           tcp_header_t *tcp0;
1300           icmp46_header_t *icmp0;
1301           snat_session_key_t key0;
1302           u32 rx_fib_index0;
1303           u32 proto0;
1304           snat_session_t *s0 = 0;
1305           clib_bihash_kv_8_8_t kv0, value0;
1306           u32 iph_offset0 = 0;
1307
1308           /* speculatively enqueue b0 to the current next frame */
1309           bi0 = from[0];
1310           to_next[0] = bi0;
1311           from += 1;
1312           to_next += 1;
1313           n_left_from -= 1;
1314           n_left_to_next -= 1;
1315
1316           b0 = vlib_get_buffer (vm, bi0);
1317           next0 = SNAT_IN2OUT_NEXT_LOOKUP;
1318
1319           if (is_output_feature)
1320             iph_offset0 = vnet_buffer (b0)->ip.save_rewrite_length;
1321
1322           ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
1323                                   iph_offset0);
1324
1325           udp0 = ip4_next_header (ip0);
1326           tcp0 = (tcp_header_t *) udp0;
1327           icmp0 = (icmp46_header_t *) udp0;
1328
1329           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1330           rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
1331                                    sw_if_index0);
1332
1333           if (PREDICT_FALSE (ip0->ttl == 1))
1334             {
1335               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1336               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
1337                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
1338                                            0);
1339               next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
1340               goto trace0;
1341             }
1342
1343           proto0 = ip_proto_to_snat_proto (ip0->protocol);
1344
1345           /* Next configured feature, probably ip4-lookup */
1346           if (is_slow_path)
1347             {
1348               if (PREDICT_FALSE (proto0 == ~0))
1349                 {
1350                   if (nat_in2out_sm_unknown_proto
1351                       (sm, b0, ip0, rx_fib_index0))
1352                     {
1353                       next0 = SNAT_IN2OUT_NEXT_DROP;
1354                       b0->error =
1355                         node->errors[SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL];
1356                     }
1357                   goto trace0;
1358                 }
1359
1360               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1361                 {
1362                   next0 = icmp_in2out_slow_path
1363                     (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1364                      next0, now, thread_index, &s0);
1365                   goto trace0;
1366                 }
1367             }
1368           else
1369             {
1370               if (PREDICT_FALSE (proto0 == ~0))
1371                 {
1372                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1373                   goto trace0;
1374                 }
1375
1376               if (ip4_is_fragment (ip0))
1377                 {
1378                   next0 = SNAT_IN2OUT_NEXT_REASS;
1379                   goto trace0;
1380                 }
1381
1382               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1383                 {
1384                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1385                   goto trace0;
1386                 }
1387             }
1388
1389           key0.addr = ip0->src_address;
1390           key0.port = udp0->src_port;
1391           key0.protocol = proto0;
1392           key0.fib_index = rx_fib_index0;
1393
1394           kv0.key = key0.as_u64;
1395
1396           if (clib_bihash_search_8_8
1397               (&sm->per_thread_data[thread_index].in2out, &kv0, &value0))
1398             {
1399               if (is_slow_path)
1400                 {
1401                   if (is_output_feature)
1402                     {
1403                       if (PREDICT_FALSE (nat_not_translate_output_feature (sm,
1404                                                                            ip0,
1405                                                                            proto0,
1406                                                                            udp0->src_port,
1407                                                                            udp0->dst_port,
1408                                                                            thread_index,
1409                                                                            sw_if_index0)))
1410                         goto trace0;
1411                     }
1412                   else
1413                     {
1414                       if (PREDICT_FALSE
1415                           (snat_not_translate
1416                            (sm, node, sw_if_index0, ip0, proto0,
1417                             rx_fib_index0, thread_index)))
1418                         goto trace0;
1419                     }
1420
1421                   next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0,
1422                                      &s0, node, next0, thread_index, now);
1423
1424                   if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
1425                     goto trace0;
1426
1427                   if (PREDICT_FALSE (!s0))
1428                     goto trace0;
1429                 }
1430               else
1431                 {
1432                   next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
1433                   goto trace0;
1434                 }
1435             }
1436           else
1437             s0 =
1438               pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
1439                                  value0.value);
1440
1441           b0->flags |= VNET_BUFFER_F_IS_NATED;
1442
1443           old_addr0 = ip0->src_address.as_u32;
1444           ip0->src_address = s0->out2in.addr;
1445           new_addr0 = ip0->src_address.as_u32;
1446           if (!is_output_feature)
1447             vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
1448
1449           sum0 = ip0->checksum;
1450           sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1451                                  ip4_header_t,
1452                                  src_address /* changed member */ );
1453           ip0->checksum = ip_csum_fold (sum0);
1454
1455           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
1456             {
1457               old_port0 = tcp0->src_port;
1458               tcp0->src_port = s0->out2in.port;
1459               new_port0 = tcp0->src_port;
1460
1461               sum0 = tcp0->checksum;
1462               sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1463                                      ip4_header_t,
1464                                      dst_address /* changed member */ );
1465               sum0 = ip_csum_update (sum0, old_port0, new_port0,
1466                                      ip4_header_t /* cheat */ ,
1467                                      length /* changed member */ );
1468               mss_clamping (sm, tcp0, &sum0);
1469               tcp0->checksum = ip_csum_fold (sum0);
1470             }
1471           else
1472             {
1473               old_port0 = udp0->src_port;
1474               udp0->src_port = s0->out2in.port;
1475               udp0->checksum = 0;
1476             }
1477
1478           /* Accounting */
1479           nat44_session_update_counters (s0, now,
1480                                          vlib_buffer_length_in_chain (vm,
1481                                                                       b0));
1482           /* Per-user LRU list maintenance */
1483           nat44_session_update_lru (sm, s0, thread_index);
1484
1485         trace0:
1486           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1487                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1488             {
1489               snat_in2out_trace_t *t =
1490                 vlib_add_trace (vm, node, b0, sizeof (*t));
1491               t->is_slow_path = is_slow_path;
1492               t->sw_if_index = sw_if_index0;
1493               t->next_index = next0;
1494               t->session_index = ~0;
1495               if (s0)
1496                 t->session_index =
1497                   s0 - sm->per_thread_data[thread_index].sessions;
1498             }
1499
1500           pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
1501
1502           /* verify speculative enqueue, maybe switch current next frame */
1503           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1504                                            to_next, n_left_to_next,
1505                                            bi0, next0);
1506         }
1507
1508       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1509     }
1510
1511   vlib_node_increment_counter (vm, stats_node_index,
1512                                SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
1513                                pkts_processed);
1514   return frame->n_vectors;
1515 }
1516
1517 static uword
1518 snat_in2out_fast_path_fn (vlib_main_t * vm,
1519                           vlib_node_runtime_t * node, vlib_frame_t * frame)
1520 {
1521   return snat_in2out_node_fn_inline (vm, node, frame, 0 /* is_slow_path */ ,
1522                                      0);
1523 }
1524
1525 /* *INDENT-OFF* */
1526 VLIB_REGISTER_NODE (snat_in2out_node) = {
1527   .function = snat_in2out_fast_path_fn,
1528   .name = "nat44-in2out",
1529   .vector_size = sizeof (u32),
1530   .format_trace = format_snat_in2out_trace,
1531   .type = VLIB_NODE_TYPE_INTERNAL,
1532
1533   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
1534   .error_strings = snat_in2out_error_strings,
1535
1536   .runtime_data_bytes = sizeof (snat_runtime_t),
1537
1538   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
1539
1540   /* edit / add dispositions here */
1541   .next_nodes = {
1542     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
1543     [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
1544     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
1545     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1546     [SNAT_IN2OUT_NEXT_REASS] = "nat44-in2out-reass",
1547   },
1548 };
1549 /* *INDENT-ON* */
1550
1551 VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_node, snat_in2out_fast_path_fn);
1552
1553 static uword
1554 snat_in2out_output_fast_path_fn (vlib_main_t * vm,
1555                                  vlib_node_runtime_t * node,
1556                                  vlib_frame_t * frame)
1557 {
1558   return snat_in2out_node_fn_inline (vm, node, frame, 0 /* is_slow_path */ ,
1559                                      1);
1560 }
1561
1562 /* *INDENT-OFF* */
1563 VLIB_REGISTER_NODE (snat_in2out_output_node) = {
1564   .function = snat_in2out_output_fast_path_fn,
1565   .name = "nat44-in2out-output",
1566   .vector_size = sizeof (u32),
1567   .format_trace = format_snat_in2out_trace,
1568   .type = VLIB_NODE_TYPE_INTERNAL,
1569
1570   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
1571   .error_strings = snat_in2out_error_strings,
1572
1573   .runtime_data_bytes = sizeof (snat_runtime_t),
1574
1575   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
1576
1577   /* edit / add dispositions here */
1578   .next_nodes = {
1579     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
1580     [SNAT_IN2OUT_NEXT_LOOKUP] = "interface-output",
1581     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-output-slowpath",
1582     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1583     [SNAT_IN2OUT_NEXT_REASS] = "nat44-in2out-reass",
1584   },
1585 };
1586 /* *INDENT-ON* */
1587
1588 VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_output_node,
1589                               snat_in2out_output_fast_path_fn);
1590
1591 static uword
1592 snat_in2out_slow_path_fn (vlib_main_t * vm,
1593                           vlib_node_runtime_t * node, vlib_frame_t * frame)
1594 {
1595   return snat_in2out_node_fn_inline (vm, node, frame, 1 /* is_slow_path */ ,
1596                                      0);
1597 }
1598
1599 /* *INDENT-OFF* */
1600 VLIB_REGISTER_NODE (snat_in2out_slowpath_node) = {
1601   .function = snat_in2out_slow_path_fn,
1602   .name = "nat44-in2out-slowpath",
1603   .vector_size = sizeof (u32),
1604   .format_trace = format_snat_in2out_trace,
1605   .type = VLIB_NODE_TYPE_INTERNAL,
1606
1607   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
1608   .error_strings = snat_in2out_error_strings,
1609
1610   .runtime_data_bytes = sizeof (snat_runtime_t),
1611
1612   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
1613
1614   /* edit / add dispositions here */
1615   .next_nodes = {
1616     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
1617     [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
1618     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
1619     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1620     [SNAT_IN2OUT_NEXT_REASS] = "nat44-in2out-reass",
1621   },
1622 };
1623 /* *INDENT-ON* */
1624
1625 VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_slowpath_node,
1626                               snat_in2out_slow_path_fn);
1627
1628 static uword
1629 snat_in2out_output_slow_path_fn (vlib_main_t * vm,
1630                                  vlib_node_runtime_t * node,
1631                                  vlib_frame_t * frame)
1632 {
1633   return snat_in2out_node_fn_inline (vm, node, frame, 1 /* is_slow_path */ ,
1634                                      1);
1635 }
1636
1637 /* *INDENT-OFF* */
1638 VLIB_REGISTER_NODE (snat_in2out_output_slowpath_node) = {
1639   .function = snat_in2out_output_slow_path_fn,
1640   .name = "nat44-in2out-output-slowpath",
1641   .vector_size = sizeof (u32),
1642   .format_trace = format_snat_in2out_trace,
1643   .type = VLIB_NODE_TYPE_INTERNAL,
1644
1645   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
1646   .error_strings = snat_in2out_error_strings,
1647
1648   .runtime_data_bytes = sizeof (snat_runtime_t),
1649
1650   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
1651
1652   /* edit / add dispositions here */
1653   .next_nodes = {
1654     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
1655     [SNAT_IN2OUT_NEXT_LOOKUP] = "interface-output",
1656     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-output-slowpath",
1657     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1658     [SNAT_IN2OUT_NEXT_REASS] = "nat44-in2out-reass",
1659   },
1660 };
1661 /* *INDENT-ON* */
1662
1663 VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_output_slowpath_node,
1664                               snat_in2out_output_slow_path_fn);
1665
1666 static uword
1667 nat44_in2out_reass_node_fn (vlib_main_t * vm,
1668                             vlib_node_runtime_t * node, vlib_frame_t * frame)
1669 {
1670   u32 n_left_from, *from, *to_next;
1671   snat_in2out_next_t next_index;
1672   u32 pkts_processed = 0;
1673   snat_main_t *sm = &snat_main;
1674   f64 now = vlib_time_now (vm);
1675   u32 thread_index = vm->thread_index;
1676   snat_main_per_thread_data_t *per_thread_data =
1677     &sm->per_thread_data[thread_index];
1678   u32 *fragments_to_drop = 0;
1679   u32 *fragments_to_loopback = 0;
1680
1681   from = vlib_frame_vector_args (frame);
1682   n_left_from = frame->n_vectors;
1683   next_index = node->cached_next_index;
1684
1685   while (n_left_from > 0)
1686     {
1687       u32 n_left_to_next;
1688
1689       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1690
1691       while (n_left_from > 0 && n_left_to_next > 0)
1692         {
1693           u32 bi0, sw_if_index0, proto0, rx_fib_index0, new_addr0, old_addr0;
1694           vlib_buffer_t *b0;
1695           u32 next0;
1696           u8 cached0 = 0;
1697           ip4_header_t *ip0;
1698           nat_reass_ip4_t *reass0;
1699           udp_header_t *udp0;
1700           tcp_header_t *tcp0;
1701           icmp46_header_t *icmp0;
1702           snat_session_key_t key0;
1703           clib_bihash_kv_8_8_t kv0, value0;
1704           snat_session_t *s0 = 0;
1705           u16 old_port0, new_port0;
1706           ip_csum_t sum0;
1707
1708           /* speculatively enqueue b0 to the current next frame */
1709           bi0 = from[0];
1710           to_next[0] = bi0;
1711           from += 1;
1712           to_next += 1;
1713           n_left_from -= 1;
1714           n_left_to_next -= 1;
1715
1716           b0 = vlib_get_buffer (vm, bi0);
1717           next0 = SNAT_IN2OUT_NEXT_LOOKUP;
1718
1719           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
1720           rx_fib_index0 =
1721             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
1722                                                  sw_if_index0);
1723
1724           if (PREDICT_FALSE (nat_reass_is_drop_frag (0)))
1725             {
1726               next0 = SNAT_IN2OUT_NEXT_DROP;
1727               b0->error = node->errors[SNAT_IN2OUT_ERROR_DROP_FRAGMENT];
1728               goto trace0;
1729             }
1730
1731           ip0 = (ip4_header_t *) vlib_buffer_get_current (b0);
1732           udp0 = ip4_next_header (ip0);
1733           tcp0 = (tcp_header_t *) udp0;
1734           icmp0 = (icmp46_header_t *) udp0;
1735           proto0 = ip_proto_to_snat_proto (ip0->protocol);
1736
1737           reass0 = nat_ip4_reass_find_or_create (ip0->src_address,
1738                                                  ip0->dst_address,
1739                                                  ip0->fragment_id,
1740                                                  ip0->protocol,
1741                                                  1, &fragments_to_drop);
1742
1743           if (PREDICT_FALSE (!reass0))
1744             {
1745               next0 = SNAT_IN2OUT_NEXT_DROP;
1746               b0->error = node->errors[SNAT_IN2OUT_ERROR_MAX_REASS];
1747               nat_log_notice ("maximum reassemblies exceeded");
1748               goto trace0;
1749             }
1750
1751           if (PREDICT_FALSE (ip4_is_first_fragment (ip0)))
1752             {
1753               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
1754                 {
1755                   next0 = icmp_in2out_slow_path
1756                     (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
1757                      next0, now, thread_index, &s0);
1758
1759                   if (PREDICT_TRUE (next0 != SNAT_IN2OUT_NEXT_DROP))
1760                     {
1761                       if (s0)
1762                         reass0->sess_index = s0 - per_thread_data->sessions;
1763                       else
1764                         reass0->flags |= NAT_REASS_FLAG_ED_DONT_TRANSLATE;
1765                       nat_ip4_reass_get_frags (reass0,
1766                                                &fragments_to_loopback);
1767                     }
1768
1769                   goto trace0;
1770                 }
1771
1772               key0.addr = ip0->src_address;
1773               key0.port = udp0->src_port;
1774               key0.protocol = proto0;
1775               key0.fib_index = rx_fib_index0;
1776               kv0.key = key0.as_u64;
1777
1778               if (clib_bihash_search_8_8
1779                   (&per_thread_data->in2out, &kv0, &value0))
1780                 {
1781                   if (PREDICT_FALSE
1782                       (snat_not_translate
1783                        (sm, node, sw_if_index0, ip0, proto0, rx_fib_index0,
1784                         thread_index)))
1785                     goto trace0;
1786
1787                   next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0,
1788                                      &s0, node, next0, thread_index, now);
1789
1790                   if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
1791                     goto trace0;
1792
1793                   if (PREDICT_FALSE (!s0))
1794                     goto trace0;
1795
1796                   reass0->sess_index = s0 - per_thread_data->sessions;
1797                 }
1798               else
1799                 {
1800                   s0 = pool_elt_at_index (per_thread_data->sessions,
1801                                           value0.value);
1802                   reass0->sess_index = value0.value;
1803                 }
1804               nat_ip4_reass_get_frags (reass0, &fragments_to_loopback);
1805             }
1806           else
1807             {
1808               if (PREDICT_FALSE (reass0->sess_index == (u32) ~ 0))
1809                 {
1810                   if (nat_ip4_reass_add_fragment
1811                       (reass0, bi0, &fragments_to_drop))
1812                     {
1813                       b0->error = node->errors[SNAT_IN2OUT_ERROR_MAX_FRAG];
1814                       nat_log_notice
1815                         ("maximum fragments per reassembly exceeded");
1816                       next0 = SNAT_IN2OUT_NEXT_DROP;
1817                       goto trace0;
1818                     }
1819                   cached0 = 1;
1820                   goto trace0;
1821                 }
1822               s0 = pool_elt_at_index (per_thread_data->sessions,
1823                                       reass0->sess_index);
1824             }
1825
1826           old_addr0 = ip0->src_address.as_u32;
1827           ip0->src_address = s0->out2in.addr;
1828           new_addr0 = ip0->src_address.as_u32;
1829           vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
1830
1831           sum0 = ip0->checksum;
1832           sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1833                                  ip4_header_t,
1834                                  src_address /* changed member */ );
1835           ip0->checksum = ip_csum_fold (sum0);
1836
1837           if (PREDICT_FALSE (ip4_is_first_fragment (ip0)))
1838             {
1839               if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
1840                 {
1841                   old_port0 = tcp0->src_port;
1842                   tcp0->src_port = s0->out2in.port;
1843                   new_port0 = tcp0->src_port;
1844
1845                   sum0 = tcp0->checksum;
1846                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
1847                                          ip4_header_t,
1848                                          dst_address /* changed member */ );
1849                   sum0 = ip_csum_update (sum0, old_port0, new_port0,
1850                                          ip4_header_t /* cheat */ ,
1851                                          length /* changed member */ );
1852                   tcp0->checksum = ip_csum_fold (sum0);
1853                 }
1854               else
1855                 {
1856                   old_port0 = udp0->src_port;
1857                   udp0->src_port = s0->out2in.port;
1858                   udp0->checksum = 0;
1859                 }
1860             }
1861
1862           /* Hairpinning */
1863           nat44_reass_hairpinning (sm, b0, ip0, s0->out2in.port,
1864                                    s0->ext_host_port, proto0, 0);
1865
1866           /* Accounting */
1867           nat44_session_update_counters (s0, now,
1868                                          vlib_buffer_length_in_chain (vm,
1869                                                                       b0));
1870           /* Per-user LRU list maintenance */
1871           nat44_session_update_lru (sm, s0, thread_index);
1872
1873         trace0:
1874           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
1875                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1876             {
1877               nat44_reass_trace_t *t =
1878                 vlib_add_trace (vm, node, b0, sizeof (*t));
1879               t->cached = cached0;
1880               t->sw_if_index = sw_if_index0;
1881               t->next_index = next0;
1882             }
1883
1884           if (cached0)
1885             {
1886               n_left_to_next++;
1887               to_next--;
1888             }
1889           else
1890             {
1891               pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
1892
1893               /* verify speculative enqueue, maybe switch current next frame */
1894               vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1895                                                to_next, n_left_to_next,
1896                                                bi0, next0);
1897             }
1898
1899           if (n_left_from == 0 && vec_len (fragments_to_loopback))
1900             {
1901               from = vlib_frame_vector_args (frame);
1902               u32 len = vec_len (fragments_to_loopback);
1903               if (len <= VLIB_FRAME_SIZE)
1904                 {
1905                   clib_memcpy_fast (from, fragments_to_loopback,
1906                                     sizeof (u32) * len);
1907                   n_left_from = len;
1908                   vec_reset_length (fragments_to_loopback);
1909                 }
1910               else
1911                 {
1912                   clib_memcpy_fast (from, fragments_to_loopback +
1913                                     (len - VLIB_FRAME_SIZE),
1914                                     sizeof (u32) * VLIB_FRAME_SIZE);
1915                   n_left_from = VLIB_FRAME_SIZE;
1916                   _vec_len (fragments_to_loopback) = len - VLIB_FRAME_SIZE;
1917                 }
1918             }
1919         }
1920
1921       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1922     }
1923
1924   vlib_node_increment_counter (vm, nat44_in2out_reass_node.index,
1925                                SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
1926                                pkts_processed);
1927
1928   nat_send_all_to_node (vm, fragments_to_drop, node,
1929                         &node->errors[SNAT_IN2OUT_ERROR_DROP_FRAGMENT],
1930                         SNAT_IN2OUT_NEXT_DROP);
1931
1932   vec_free (fragments_to_drop);
1933   vec_free (fragments_to_loopback);
1934   return frame->n_vectors;
1935 }
1936
1937 /* *INDENT-OFF* */
1938 VLIB_REGISTER_NODE (nat44_in2out_reass_node) = {
1939   .function = nat44_in2out_reass_node_fn,
1940   .name = "nat44-in2out-reass",
1941   .vector_size = sizeof (u32),
1942   .format_trace = format_nat44_reass_trace,
1943   .type = VLIB_NODE_TYPE_INTERNAL,
1944
1945   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
1946   .error_strings = snat_in2out_error_strings,
1947
1948   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
1949   .next_nodes = {
1950     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
1951     [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
1952     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
1953     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
1954     [SNAT_IN2OUT_NEXT_REASS] = "nat44-in2out-reass",
1955   },
1956 };
1957 /* *INDENT-ON* */
1958
1959 VLIB_NODE_FUNCTION_MULTIARCH (nat44_in2out_reass_node,
1960                               nat44_in2out_reass_node_fn);
1961
1962 static uword
1963 snat_in2out_fast_static_map_fn (vlib_main_t * vm,
1964                                 vlib_node_runtime_t * node,
1965                                 vlib_frame_t * frame)
1966 {
1967   u32 n_left_from, *from, *to_next;
1968   snat_in2out_next_t next_index;
1969   u32 pkts_processed = 0;
1970   snat_main_t *sm = &snat_main;
1971   u32 stats_node_index;
1972
1973   stats_node_index = snat_in2out_fast_node.index;
1974
1975   from = vlib_frame_vector_args (frame);
1976   n_left_from = frame->n_vectors;
1977   next_index = node->cached_next_index;
1978
1979   while (n_left_from > 0)
1980     {
1981       u32 n_left_to_next;
1982
1983       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1984
1985       while (n_left_from > 0 && n_left_to_next > 0)
1986         {
1987           u32 bi0;
1988           vlib_buffer_t *b0;
1989           u32 next0;
1990           u32 sw_if_index0;
1991           ip4_header_t *ip0;
1992           ip_csum_t sum0;
1993           u32 new_addr0, old_addr0;
1994           u16 old_port0, new_port0;
1995           udp_header_t *udp0;
1996           tcp_header_t *tcp0;
1997           icmp46_header_t *icmp0;
1998           snat_session_key_t key0, sm0;
1999           u32 proto0;
2000           u32 rx_fib_index0;
2001
2002           /* speculatively enqueue b0 to the current next frame */
2003           bi0 = from[0];
2004           to_next[0] = bi0;
2005           from += 1;
2006           to_next += 1;
2007           n_left_from -= 1;
2008           n_left_to_next -= 1;
2009
2010           b0 = vlib_get_buffer (vm, bi0);
2011           next0 = SNAT_IN2OUT_NEXT_LOOKUP;
2012
2013           ip0 = vlib_buffer_get_current (b0);
2014           udp0 = ip4_next_header (ip0);
2015           tcp0 = (tcp_header_t *) udp0;
2016           icmp0 = (icmp46_header_t *) udp0;
2017
2018           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2019           rx_fib_index0 =
2020             ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
2021
2022           if (PREDICT_FALSE (ip0->ttl == 1))
2023             {
2024               vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
2025               icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
2026                                            ICMP4_time_exceeded_ttl_exceeded_in_transit,
2027                                            0);
2028               next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
2029               goto trace0;
2030             }
2031
2032           proto0 = ip_proto_to_snat_proto (ip0->protocol);
2033
2034           if (PREDICT_FALSE (proto0 == ~0))
2035             goto trace0;
2036
2037           if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
2038             {
2039               next0 = icmp_in2out (sm, b0, ip0, icmp0, sw_if_index0,
2040                                    rx_fib_index0, node, next0, ~0, 0, 0);
2041               goto trace0;
2042             }
2043
2044           key0.addr = ip0->src_address;
2045           key0.protocol = proto0;
2046           key0.port = udp0->src_port;
2047           key0.fib_index = rx_fib_index0;
2048
2049           if (snat_static_mapping_match (sm, key0, &sm0, 0, 0, 0, 0, 0, 0))
2050             {
2051               b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
2052               next0 = SNAT_IN2OUT_NEXT_DROP;
2053               goto trace0;
2054             }
2055
2056           new_addr0 = sm0.addr.as_u32;
2057           new_port0 = sm0.port;
2058           vnet_buffer (b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
2059           old_addr0 = ip0->src_address.as_u32;
2060           ip0->src_address.as_u32 = new_addr0;
2061
2062           sum0 = ip0->checksum;
2063           sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
2064                                  ip4_header_t,
2065                                  src_address /* changed member */ );
2066           ip0->checksum = ip_csum_fold (sum0);
2067
2068           if (PREDICT_FALSE (new_port0 != udp0->dst_port))
2069             {
2070               if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
2071                 {
2072                   old_port0 = tcp0->src_port;
2073                   tcp0->src_port = new_port0;
2074
2075                   sum0 = tcp0->checksum;
2076                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
2077                                          ip4_header_t,
2078                                          dst_address /* changed member */ );
2079                   sum0 = ip_csum_update (sum0, old_port0, new_port0,
2080                                          ip4_header_t /* cheat */ ,
2081                                          length /* changed member */ );
2082                   mss_clamping (sm, tcp0, &sum0);
2083                   tcp0->checksum = ip_csum_fold (sum0);
2084                 }
2085               else
2086                 {
2087                   old_port0 = udp0->src_port;
2088                   udp0->src_port = new_port0;
2089                   udp0->checksum = 0;
2090                 }
2091             }
2092           else
2093             {
2094               if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
2095                 {
2096                   sum0 = tcp0->checksum;
2097                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
2098                                          ip4_header_t,
2099                                          dst_address /* changed member */ );
2100                   mss_clamping (sm, tcp0, &sum0);
2101                   tcp0->checksum = ip_csum_fold (sum0);
2102                 }
2103             }
2104
2105           /* Hairpinning */
2106           snat_hairpinning (sm, b0, ip0, udp0, tcp0, proto0, 0);
2107
2108         trace0:
2109           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
2110                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
2111             {
2112               snat_in2out_trace_t *t =
2113                 vlib_add_trace (vm, node, b0, sizeof (*t));
2114               t->sw_if_index = sw_if_index0;
2115               t->next_index = next0;
2116             }
2117
2118           pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
2119
2120           /* verify speculative enqueue, maybe switch current next frame */
2121           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
2122                                            to_next, n_left_to_next,
2123                                            bi0, next0);
2124         }
2125
2126       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2127     }
2128
2129   vlib_node_increment_counter (vm, stats_node_index,
2130                                SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
2131                                pkts_processed);
2132   return frame->n_vectors;
2133 }
2134
2135
2136 /* *INDENT-OFF* */
2137 VLIB_REGISTER_NODE (snat_in2out_fast_node) = {
2138   .function = snat_in2out_fast_static_map_fn,
2139   .name = "nat44-in2out-fast",
2140   .vector_size = sizeof (u32),
2141   .format_trace = format_snat_in2out_fast_trace,
2142   .type = VLIB_NODE_TYPE_INTERNAL,
2143
2144   .n_errors = ARRAY_LEN(snat_in2out_error_strings),
2145   .error_strings = snat_in2out_error_strings,
2146
2147   .runtime_data_bytes = sizeof (snat_runtime_t),
2148
2149   .n_next_nodes = SNAT_IN2OUT_N_NEXT,
2150
2151   /* edit / add dispositions here */
2152   .next_nodes = {
2153     [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
2154     [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
2155     [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
2156     [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
2157     [SNAT_IN2OUT_NEXT_REASS] = "nat44-in2out-reass",
2158   },
2159 };
2160 /* *INDENT-ON* */
2161
2162 VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_fast_node,
2163                               snat_in2out_fast_static_map_fn);
2164
2165 /*
2166  * fd.io coding-style-patch-verification: ON
2167  *
2168  * Local Variables:
2169  * eval: (c-set-style "gnu")
2170  * End:
2171  */