src/plugins/nat/nat44_classify.c

   1 /*
   2  * Copyright (c) 2018 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 Classify for one armed NAT44 (in+out interface)
  18  */
  19
  20 #include <vlib/vlib.h>
  21 #include <vnet/vnet.h>
  22 #include <vnet/fib/ip4_fib.h>
  23 #include <nat/nat.h>
  24 #include <nat/nat_inlines.h>
  25
  26 #define foreach_nat44_classify_error                      \
  27 _(NEXT_IN2OUT, "next in2out")                             \
  28 _(NEXT_OUT2IN, "next out2in")                             \
  29 _(FRAG_CACHED, "fragment cached")
  30
  31 typedef enum
  32 {
  33 #define _(sym,str) NAT44_CLASSIFY_ERROR_##sym,
  34   foreach_nat44_classify_error
  35 #undef _
  36     NAT44_CLASSIFY_N_ERROR,
  37 } nat44_classify_error_t;
  38
  39 static char *nat44_classify_error_strings[] = {
  40 #define _(sym,string) string,
  41   foreach_nat44_classify_error
  42 #undef _
  43 };
  44
  45 typedef enum
  46 {
  47   NAT44_CLASSIFY_NEXT_IN2OUT,
  48   NAT44_CLASSIFY_NEXT_OUT2IN,
  49   NAT44_CLASSIFY_NEXT_DROP,
  50   NAT44_CLASSIFY_N_NEXT,
  51 } nat44_classify_next_t;
  52
  53 typedef struct
  54 {
  55   u8 next_in2out;
  56   u8 cached;
  57 } nat44_classify_trace_t;
  58
  59 static u8 *
  60 format_nat44_classify_trace (u8 * s, va_list * args)
  61 {
  62   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  63   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  64   nat44_classify_trace_t *t = va_arg (*args, nat44_classify_trace_t *);
  65   char *next;
  66
  67   if (t->cached)
  68     s = format (s, "nat44-classify: fragment cached");
  69   else
  70     {
  71       next = t->next_in2out ? "nat44-in2out" : "nat44-out2in";
  72       s = format (s, "nat44-classify: next %s", next);
  73     }
  74
  75   return s;
  76 }
  77
  78 static inline uword
  79 nat44_classify_node_fn_inline (vlib_main_t * vm,
  80                                vlib_node_runtime_t * node,
  81                                vlib_frame_t * frame)
  82 {
  83   u32 n_left_from, *from, *to_next;
  84   nat44_classify_next_t next_index;
  85   snat_main_t *sm = &snat_main;
  86   snat_static_mapping_t *m;
  87   u32 *fragments_to_drop = 0;
  88   u32 next_in2out = 0, next_out2in = 0;
  89
  90   from = vlib_frame_vector_args (frame);
  91   n_left_from = frame->n_vectors;
  92   next_index = node->cached_next_index;
  93
  94   while (n_left_from > 0)
  95     {
  96       u32 n_left_to_next;
  97
  98       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
  99
 100       while (n_left_from > 0 && n_left_to_next > 0)
 101         {
 102           u32 bi0;
 103           vlib_buffer_t *b0;
 104           u32 next0 = NAT44_CLASSIFY_NEXT_IN2OUT;
 105           ip4_header_t *ip0;
 106           snat_address_t *ap;
 107           snat_session_key_t m_key0;
 108           clib_bihash_kv_8_8_t kv0, value0;
 109
 110           /* speculatively enqueue b0 to the current next frame */
 111           bi0 = from[0];
 112           to_next[0] = bi0;
 113           from += 1;
 114           to_next += 1;
 115           n_left_from -= 1;
 116           n_left_to_next -= 1;
 117
 118           b0 = vlib_get_buffer (vm, bi0);
 119           ip0 = vlib_buffer_get_current (b0);
 120
 121           /* *INDENT-OFF* */
 122           vec_foreach (ap, sm->addresses)
 123             {
 124               if (ip0->dst_address.as_u32 == ap->addr.as_u32)
 125                 {
 126                   next0 = NAT44_CLASSIFY_NEXT_OUT2IN;
 127                   goto enqueue0;
 128                 }
 129             }
 130           /* *INDENT-ON* */
 131
 132           if (PREDICT_FALSE (pool_elts (sm->static_mappings)))
 133             {
 134               m_key0.addr = ip0->dst_address;
 135               m_key0.port = 0;
 136               m_key0.protocol = 0;
 137               m_key0.fib_index = 0;
 138               kv0.key = m_key0.as_u64;
 139               /* try to classify the fragment based on IP header alone */
 140               if (!clib_bihash_search_8_8 (&sm->static_mapping_by_external,
 141                                            &kv0, &value0))
 142                 {
 143                   m = pool_elt_at_index (sm->static_mappings, value0.value);
 144                   if (m->local_addr.as_u32 != m->external_addr.as_u32)
 145                     next0 = NAT44_CLASSIFY_NEXT_OUT2IN;
 146                   goto enqueue0;
 147                 }
 148               m_key0.port =
 149                 clib_net_to_host_u16 (vnet_buffer (b0)->ip.reass.l4_dst_port);
 150               m_key0.protocol = ip_proto_to_snat_proto (ip0->protocol);
 151               kv0.key = m_key0.as_u64;
 152               if (!clib_bihash_search_8_8
 153                   (&sm->static_mapping_by_external, &kv0, &value0))
 154                 {
 155                   m = pool_elt_at_index (sm->static_mappings, value0.value);
 156                   if (m->local_addr.as_u32 != m->external_addr.as_u32)
 157                     next0 = NAT44_CLASSIFY_NEXT_OUT2IN;
 158                 }
 159             }
 160
 161         enqueue0:
 162           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 163                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 164             {
 165               nat44_classify_trace_t *t =
 166                 vlib_add_trace (vm, node, b0, sizeof (*t));
 167               t->cached = 0;
 168               t->next_in2out = next0 == NAT44_CLASSIFY_NEXT_IN2OUT ? 1 : 0;
 169             }
 170
 171           next_in2out += next0 == NAT44_CLASSIFY_NEXT_IN2OUT;
 172           next_out2in += next0 == NAT44_CLASSIFY_NEXT_OUT2IN;
 173
 174           /* verify speculative enqueue, maybe switch current next frame */
 175           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 176                                            to_next, n_left_to_next,
 177                                            bi0, next0);
 178         }
 179
 180       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 181     }
 182
 183   nat_send_all_to_node (vm, fragments_to_drop, node, 0,
 184                         NAT44_CLASSIFY_NEXT_DROP);
 185
 186   vec_free (fragments_to_drop);
 187
 188   vlib_node_increment_counter (vm, node->node_index,
 189                                NAT44_CLASSIFY_ERROR_NEXT_IN2OUT, next_in2out);
 190   vlib_node_increment_counter (vm, node->node_index,
 191                                NAT44_CLASSIFY_ERROR_NEXT_OUT2IN, next_out2in);
 192   return frame->n_vectors;
 193 }
 194
 195 static inline uword
 196 nat44_handoff_classify_node_fn_inline (vlib_main_t * vm,
 197                                        vlib_node_runtime_t * node,
 198                                        vlib_frame_t * frame)
 199 {
 200   u32 n_left_from, *from, *to_next;
 201   nat44_classify_next_t next_index;
 202   snat_main_t *sm = &snat_main;
 203   snat_static_mapping_t *m;
 204   u32 *fragments_to_drop = 0;
 205   u32 next_in2out = 0, next_out2in = 0;
 206
 207   from = vlib_frame_vector_args (frame);
 208   n_left_from = frame->n_vectors;
 209   next_index = node->cached_next_index;
 210
 211   while (n_left_from > 0)
 212     {
 213       u32 n_left_to_next;
 214
 215       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 216
 217       while (n_left_from > 0 && n_left_to_next > 0)
 218         {
 219           u32 bi0;
 220           vlib_buffer_t *b0;
 221           u32 next0 = NAT_NEXT_IN2OUT_CLASSIFY;
 222           ip4_header_t *ip0;
 223           snat_address_t *ap;
 224           snat_session_key_t m_key0;
 225           clib_bihash_kv_8_8_t kv0, value0;
 226
 227           /* speculatively enqueue b0 to the current next frame */
 228           bi0 = from[0];
 229           to_next[0] = bi0;
 230           from += 1;
 231           to_next += 1;
 232           n_left_from -= 1;
 233           n_left_to_next -= 1;
 234
 235           b0 = vlib_get_buffer (vm, bi0);
 236           ip0 = vlib_buffer_get_current (b0);
 237
 238           /* *INDENT-OFF* */
 239           vec_foreach (ap, sm->addresses)
 240             {
 241               if (ip0->dst_address.as_u32 == ap->addr.as_u32)
 242                 {
 243                   next0 = NAT_NEXT_OUT2IN_CLASSIFY;
 244                   goto enqueue0;
 245                 }
 246             }
 247           /* *INDENT-ON* */
 248
 249           if (PREDICT_FALSE (pool_elts (sm->static_mappings)))
 250             {
 251               m_key0.addr = ip0->dst_address;
 252               m_key0.port = 0;
 253               m_key0.protocol = 0;
 254               m_key0.fib_index = 0;
 255               kv0.key = m_key0.as_u64;
 256               /* try to classify the fragment based on IP header alone */
 257               if (!clib_bihash_search_8_8 (&sm->static_mapping_by_external,
 258                                            &kv0, &value0))
 259                 {
 260                   m = pool_elt_at_index (sm->static_mappings, value0.value);
 261                   if (m->local_addr.as_u32 != m->external_addr.as_u32)
 262                     next0 = NAT_NEXT_OUT2IN_CLASSIFY;
 263                   goto enqueue0;
 264                 }
 265               m_key0.port =
 266                 clib_net_to_host_u16 (vnet_buffer (b0)->ip.reass.l4_dst_port);
 267               m_key0.protocol = ip_proto_to_snat_proto (ip0->protocol);
 268               kv0.key = m_key0.as_u64;
 269               if (!clib_bihash_search_8_8
 270                   (&sm->static_mapping_by_external, &kv0, &value0))
 271                 {
 272                   m = pool_elt_at_index (sm->static_mappings, value0.value);
 273                   if (m->local_addr.as_u32 != m->external_addr.as_u32)
 274                     next0 = NAT_NEXT_OUT2IN_CLASSIFY;
 275                 }
 276             }
 277
 278         enqueue0:
 279           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 280                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 281             {
 282               nat44_classify_trace_t *t =
 283                 vlib_add_trace (vm, node, b0, sizeof (*t));
 284               t->cached = 0;
 285               t->next_in2out = next0 == NAT_NEXT_IN2OUT_CLASSIFY ? 1 : 0;
 286             }
 287
 288           next_in2out += next0 == NAT_NEXT_IN2OUT_CLASSIFY;
 289           next_out2in += next0 == NAT_NEXT_OUT2IN_CLASSIFY;
 290
 291           /* verify speculative enqueue, maybe switch current next frame */
 292           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 293                                            to_next, n_left_to_next,
 294                                            bi0, next0);
 295         }
 296
 297       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 298     }
 299
 300   nat_send_all_to_node (vm, fragments_to_drop, node, 0, NAT_NEXT_DROP);
 301
 302   vec_free (fragments_to_drop);
 303
 304   vlib_node_increment_counter (vm, node->node_index,
 305                                NAT44_CLASSIFY_ERROR_NEXT_IN2OUT, next_in2out);
 306   vlib_node_increment_counter (vm, node->node_index,
 307                                NAT44_CLASSIFY_ERROR_NEXT_OUT2IN, next_out2in);
 308   return frame->n_vectors;
 309 }
 310
 311 static inline uword
 312 nat44_ed_classify_node_fn_inline (vlib_main_t * vm,
 313                                   vlib_node_runtime_t * node,
 314                                   vlib_frame_t * frame)
 315 {
 316   u32 n_left_from, *from, *to_next;
 317   nat44_classify_next_t next_index;
 318   snat_main_t *sm = &snat_main;
 319   snat_static_mapping_t *m;
 320   u32 thread_index = vm->thread_index;
 321   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 322   u32 *fragments_to_drop = 0;
 323   u32 next_in2out = 0, next_out2in = 0;
 324
 325   from = vlib_frame_vector_args (frame);
 326   n_left_from = frame->n_vectors;
 327   next_index = node->cached_next_index;
 328
 329   while (n_left_from > 0)
 330     {
 331       u32 n_left_to_next;
 332
 333       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 334
 335       while (n_left_from > 0 && n_left_to_next > 0)
 336         {
 337           u32 bi0;
 338           vlib_buffer_t *b0;
 339           u32 next0 = NAT_NEXT_IN2OUT_ED_FAST_PATH;
 340           u32 sw_if_index0, rx_fib_index0;
 341           ip4_header_t *ip0;
 342           snat_address_t *ap;
 343           snat_session_key_t m_key0;
 344           clib_bihash_kv_8_8_t kv0, value0;
 345           clib_bihash_kv_16_8_t ed_kv0, ed_value0;
 346
 347           /* speculatively enqueue b0 to the current next frame */
 348           bi0 = from[0];
 349           to_next[0] = bi0;
 350           from += 1;
 351           to_next += 1;
 352           n_left_from -= 1;
 353           n_left_to_next -= 1;
 354
 355           b0 = vlib_get_buffer (vm, bi0);
 356           ip0 = vlib_buffer_get_current (b0);
 357
 358           u32 arc_next;
 359           vnet_feature_next (&arc_next, b0);
 360           vnet_buffer2 (b0)->nat.arc_next = arc_next;
 361
 362           if (ip0->protocol != IP_PROTOCOL_ICMP)
 363             {
 364               /* process leading fragment/whole packet (with L4 header) */
 365               sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 366               rx_fib_index0 =
 367                 fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 368                                                      sw_if_index0);
 369               make_ed_kv (&ip0->src_address, &ip0->dst_address,
 370                           ip0->protocol, rx_fib_index0,
 371                           vnet_buffer (b0)->ip.reass.l4_src_port,
 372                           vnet_buffer (b0)->ip.reass.l4_dst_port, ~0ULL,
 373                           &ed_kv0);
 374               /* process whole packet */
 375               if (!clib_bihash_search_16_8
 376                   (&tsm->in2out_ed, &ed_kv0, &ed_value0))
 377                 goto enqueue0;
 378               /* session doesn't exist so continue in code */
 379             }
 380
 381           /* *INDENT-OFF* */
 382           vec_foreach (ap, sm->addresses)
 383             {
 384               if (ip0->dst_address.as_u32 == ap->addr.as_u32)
 385                 {
 386                   next0 = NAT_NEXT_OUT2IN_ED_FAST_PATH;
 387                   goto enqueue0;
 388                 }
 389             }
 390           /* *INDENT-ON* */
 391
 392           if (PREDICT_FALSE (pool_elts (sm->static_mappings)))
 393             {
 394               m_key0.addr = ip0->dst_address;
 395               m_key0.port = 0;
 396               m_key0.protocol = 0;
 397               m_key0.fib_index = 0;
 398               kv0.key = m_key0.as_u64;
 399               /* try to classify the fragment based on IP header alone */
 400               if (!clib_bihash_search_8_8 (&sm->static_mapping_by_external,
 401                                            &kv0, &value0))
 402                 {
 403                   m = pool_elt_at_index (sm->static_mappings, value0.value);
 404                   if (m->local_addr.as_u32 != m->external_addr.as_u32)
 405                     next0 = NAT_NEXT_OUT2IN_ED_FAST_PATH;
 406                   goto enqueue0;
 407                 }
 408               m_key0.port =
 409                 clib_net_to_host_u16 (vnet_buffer (b0)->ip.reass.l4_dst_port);
 410               m_key0.protocol = ip_proto_to_snat_proto (ip0->protocol);
 411               kv0.key = m_key0.as_u64;
 412               if (!clib_bihash_search_8_8
 413                   (&sm->static_mapping_by_external, &kv0, &value0))
 414                 {
 415                   m = pool_elt_at_index (sm->static_mappings, value0.value);
 416                   if (m->local_addr.as_u32 != m->external_addr.as_u32)
 417                     next0 = NAT_NEXT_OUT2IN_ED_FAST_PATH;
 418                 }
 419             }
 420
 421         enqueue0:
 422           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 423                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 424             {
 425               nat44_classify_trace_t *t =
 426                 vlib_add_trace (vm, node, b0, sizeof (*t));
 427               t->cached = 0;
 428               t->next_in2out = next0 == NAT_NEXT_IN2OUT_ED_FAST_PATH ? 1 : 0;
 429             }
 430
 431           next_in2out += next0 == NAT_NEXT_IN2OUT_ED_FAST_PATH;
 432           next_out2in += next0 == NAT_NEXT_OUT2IN_ED_FAST_PATH;
 433
 434           /* verify speculative enqueue, maybe switch current next frame */
 435           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 436                                            to_next, n_left_to_next,
 437                                            bi0, next0);
 438         }
 439
 440       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 441     }
 442
 443   nat_send_all_to_node (vm, fragments_to_drop, node, 0,
 444                         NAT44_CLASSIFY_NEXT_DROP);
 445
 446   vec_free (fragments_to_drop);
 447
 448   vlib_node_increment_counter (vm, node->node_index,
 449                                NAT44_CLASSIFY_ERROR_NEXT_IN2OUT, next_in2out);
 450   vlib_node_increment_counter (vm, node->node_index,
 451                                NAT44_CLASSIFY_ERROR_NEXT_OUT2IN, next_out2in);
 452   return frame->n_vectors;
 453 }
 454
 455 VLIB_NODE_FN (nat44_classify_node) (vlib_main_t * vm,
 456                                     vlib_node_runtime_t * node,
 457                                     vlib_frame_t * frame)
 458 {
 459   return nat44_classify_node_fn_inline (vm, node, frame);
 460 }
 461
 462 /* *INDENT-OFF* */
 463 VLIB_REGISTER_NODE (nat44_classify_node) = {
 464   .name = "nat44-classify",
 465   .vector_size = sizeof (u32),
 466   .format_trace = format_nat44_classify_trace,
 467   .type = VLIB_NODE_TYPE_INTERNAL,
 468   .n_errors = ARRAY_LEN(nat44_classify_error_strings),
 469   .error_strings = nat44_classify_error_strings,
 470   .n_next_nodes = NAT44_CLASSIFY_N_NEXT,
 471   .next_nodes = {
 472     [NAT44_CLASSIFY_NEXT_IN2OUT] = "nat44-in2out",
 473     [NAT44_CLASSIFY_NEXT_OUT2IN] = "nat44-out2in",
 474     [NAT44_CLASSIFY_NEXT_DROP] = "error-drop",
 475   },
 476 };
 477 /* *INDENT-ON* */
 478
 479 VLIB_NODE_FN (nat44_ed_classify_node) (vlib_main_t * vm,
 480                                        vlib_node_runtime_t * node,
 481                                        vlib_frame_t * frame)
 482 {
 483   return nat44_ed_classify_node_fn_inline (vm, node, frame);
 484 }
 485
 486 /* *INDENT-OFF* */
 487 VLIB_REGISTER_NODE (nat44_ed_classify_node) = {
 488   .name = "nat44-ed-classify",
 489   .vector_size = sizeof (u32),
 490   .sibling_of = "nat-default",
 491   .format_trace = format_nat44_classify_trace,
 492   .type = VLIB_NODE_TYPE_INTERNAL,
 493 };
 494 /* *INDENT-ON* */
 495
 496 VLIB_NODE_FN (nat44_det_classify_node) (vlib_main_t * vm,
 497                                         vlib_node_runtime_t * node,
 498                                         vlib_frame_t * frame)
 499 {
 500   return nat44_classify_node_fn_inline (vm, node, frame);
 501 }
 502
 503 /* *INDENT-OFF* */
 504 VLIB_REGISTER_NODE (nat44_det_classify_node) = {
 505   .name = "nat44-det-classify",
 506   .vector_size = sizeof (u32),
 507   .format_trace = format_nat44_classify_trace,
 508   .type = VLIB_NODE_TYPE_INTERNAL,
 509   .n_next_nodes = NAT44_CLASSIFY_N_NEXT,
 510   .next_nodes = {
 511     [NAT44_CLASSIFY_NEXT_IN2OUT] = "nat44-det-in2out",
 512     [NAT44_CLASSIFY_NEXT_OUT2IN] = "nat44-det-out2in",
 513     [NAT44_CLASSIFY_NEXT_DROP] = "error-drop",
 514   },
 515 };
 516 /* *INDENT-ON* */
 517
 518 VLIB_NODE_FN (nat44_handoff_classify_node) (vlib_main_t * vm,
 519                                             vlib_node_runtime_t * node,
 520                                             vlib_frame_t * frame)
 521 {
 522   return nat44_handoff_classify_node_fn_inline (vm, node, frame);
 523 }
 524
 525 /* *INDENT-OFF* */
 526 VLIB_REGISTER_NODE (nat44_handoff_classify_node) = {
 527   .name = "nat44-handoff-classify",
 528   .vector_size = sizeof (u32),
 529   .sibling_of = "nat-default",
 530   .format_trace = format_nat44_classify_trace,
 531   .type = VLIB_NODE_TYPE_INTERNAL,
 532 };
 533
 534 /* *INDENT-ON* */
 535
 536 /*
 537  * fd.io coding-style-patch-verification: ON
 538  *
 539  * Local Variables:
 540  * eval: (c-set-style "gnu")
 541  * End:
 542  */