src/plugins/nat/dslite_in2out.c

   1 /*
   2  * Copyright (c) 2017 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 #include <nat/dslite.h>
  16 #include <nat/nat_inlines.h>
  17 #include <nat/nat_syslog.h>
  18
  19 typedef enum
  20 {
  21   DSLITE_IN2OUT_NEXT_IP4_LOOKUP,
  22   DSLITE_IN2OUT_NEXT_IP6_ICMP,
  23   DSLITE_IN2OUT_NEXT_DROP,
  24   DSLITE_IN2OUT_NEXT_SLOWPATH,
  25   DSLITE_IN2OUT_N_NEXT,
  26 } dslite_in2out_next_t;
  27
  28 static char *dslite_in2out_error_strings[] = {
  29 #define _(sym,string) string,
  30   foreach_dslite_error
  31 #undef _
  32 };
  33
  34 static u32
  35 slow_path (dslite_main_t * dm, dslite_session_key_t * in2out_key,
  36            dslite_session_t ** sp, u32 next, u8 * error, u32 thread_index)
  37 {
  38   dslite_b4_t *b4;
  39   clib_bihash_kv_16_8_t b4_kv, b4_value;
  40   clib_bihash_kv_24_8_t in2out_kv;
  41   clib_bihash_kv_8_8_t out2in_kv;
  42   dlist_elt_t *head_elt, *oldest_elt, *elt;
  43   u32 oldest_index;
  44   dslite_session_t *s;
  45   snat_session_key_t out2in_key;
  46   u32 b4_index;
  47
  48   out2in_key.protocol = in2out_key->proto;
  49   out2in_key.fib_index = 0;
  50
  51   b4_kv.key[0] = in2out_key->softwire_id.as_u64[0];
  52   b4_kv.key[1] = in2out_key->softwire_id.as_u64[1];
  53
  54   if (clib_bihash_search_16_8
  55       (&dm->per_thread_data[thread_index].b4_hash, &b4_kv, &b4_value))
  56     {
  57       pool_get (dm->per_thread_data[thread_index].b4s, b4);
  58       clib_memset (b4, 0, sizeof (*b4));
  59       b4->addr.as_u64[0] = in2out_key->softwire_id.as_u64[0];
  60       b4->addr.as_u64[1] = in2out_key->softwire_id.as_u64[1];
  61
  62       pool_get (dm->per_thread_data[thread_index].list_pool, head_elt);
  63       b4->sessions_per_b4_list_head_index =
  64         head_elt - dm->per_thread_data[thread_index].list_pool;
  65       clib_dlist_init (dm->per_thread_data[thread_index].list_pool,
  66                        b4->sessions_per_b4_list_head_index);
  67
  68       b4_index = b4_kv.value = b4 - dm->per_thread_data[thread_index].b4s;
  69       clib_bihash_add_del_16_8 (&dm->per_thread_data[thread_index].b4_hash,
  70                                 &b4_kv, 1);
  71
  72       vlib_set_simple_counter (&dm->total_b4s, thread_index, 0,
  73                                pool_elts (dm->
  74                                           per_thread_data[thread_index].b4s));
  75     }
  76   else
  77     {
  78       b4_index = b4_value.value;
  79       b4 =
  80         pool_elt_at_index (dm->per_thread_data[thread_index].b4s,
  81                            b4_value.value);
  82     }
  83
  84   //TODO configurable quota
  85   if (b4->nsessions >= 1000)
  86     {
  87       oldest_index =
  88         clib_dlist_remove_head (dm->per_thread_data[thread_index].list_pool,
  89                                 b4->sessions_per_b4_list_head_index);
  90       ASSERT (oldest_index != ~0);
  91       clib_dlist_addtail (dm->per_thread_data[thread_index].list_pool,
  92                           b4->sessions_per_b4_list_head_index, oldest_index);
  93       oldest_elt =
  94         pool_elt_at_index (dm->per_thread_data[thread_index].list_pool,
  95                            oldest_index);
  96       s =
  97         pool_elt_at_index (dm->per_thread_data[thread_index].sessions,
  98                            oldest_elt->value);
  99
 100       in2out_kv.key[0] = s->in2out.as_u64[0];
 101       in2out_kv.key[1] = s->in2out.as_u64[1];
 102       in2out_kv.key[2] = s->in2out.as_u64[2];
 103       clib_bihash_add_del_24_8 (&dm->per_thread_data[thread_index].in2out,
 104                                 &in2out_kv, 0);
 105       out2in_kv.key = s->out2in.as_u64;
 106       clib_bihash_add_del_8_8 (&dm->per_thread_data[thread_index].out2in,
 107                                &out2in_kv, 0);
 108       snat_free_outside_address_and_port (dm->addr_pool, thread_index,
 109                                           &s->out2in);
 110
 111       nat_syslog_dslite_apmdel (b4_index, &s->in2out.softwire_id,
 112                                 &s->in2out.addr, s->in2out.port,
 113                                 &s->out2in.addr, s->out2in.port,
 114                                 s->in2out.proto);
 115
 116       if (snat_alloc_outside_address_and_port
 117           (dm->addr_pool, 0, thread_index, &out2in_key,
 118            dm->port_per_thread, thread_index))
 119         ASSERT (0);
 120     }
 121   else
 122     {
 123       if (snat_alloc_outside_address_and_port
 124           (dm->addr_pool, 0, thread_index, &out2in_key,
 125            dm->port_per_thread, thread_index))
 126         {
 127           *error = DSLITE_ERROR_OUT_OF_PORTS;
 128           return DSLITE_IN2OUT_NEXT_DROP;
 129         }
 130       pool_get (dm->per_thread_data[thread_index].sessions, s);
 131       clib_memset (s, 0, sizeof (*s));
 132       b4->nsessions++;
 133
 134       pool_get (dm->per_thread_data[thread_index].list_pool, elt);
 135       clib_dlist_init (dm->per_thread_data[thread_index].list_pool,
 136                        elt - dm->per_thread_data[thread_index].list_pool);
 137       elt->value = s - dm->per_thread_data[thread_index].sessions;
 138       s->per_b4_index = elt - dm->per_thread_data[thread_index].list_pool;
 139       s->per_b4_list_head_index = b4->sessions_per_b4_list_head_index;
 140       clib_dlist_addtail (dm->per_thread_data[thread_index].list_pool,
 141                           s->per_b4_list_head_index,
 142                           elt - dm->per_thread_data[thread_index].list_pool);
 143
 144       vlib_set_simple_counter (&dm->total_sessions, thread_index, 0,
 145                                pool_elts (dm->per_thread_data
 146                                           [thread_index].sessions));
 147     }
 148
 149   s->in2out = *in2out_key;
 150   s->out2in = out2in_key;
 151   *sp = s;
 152   in2out_kv.key[0] = s->in2out.as_u64[0];
 153   in2out_kv.key[1] = s->in2out.as_u64[1];
 154   in2out_kv.key[2] = s->in2out.as_u64[2];
 155   in2out_kv.value = s - dm->per_thread_data[thread_index].sessions;
 156   clib_bihash_add_del_24_8 (&dm->per_thread_data[thread_index].in2out,
 157                             &in2out_kv, 1);
 158   out2in_kv.key = s->out2in.as_u64;
 159   out2in_kv.value = s - dm->per_thread_data[thread_index].sessions;
 160   clib_bihash_add_del_8_8 (&dm->per_thread_data[thread_index].out2in,
 161                            &out2in_kv, 1);
 162
 163   nat_syslog_dslite_apmadd (b4_index, &s->in2out.softwire_id, &s->in2out.addr,
 164                             s->in2out.port, &s->out2in.addr, s->out2in.port,
 165                             s->in2out.proto);
 166
 167   return next;
 168 }
 169
 170 static inline u32
 171 dslite_icmp_in2out (dslite_main_t * dm, ip6_header_t * ip6,
 172                     ip4_header_t * ip4, dslite_session_t ** sp, u32 next,
 173                     u8 * error, u32 thread_index)
 174 {
 175   dslite_session_t *s = 0;
 176   icmp46_header_t *icmp = ip4_next_header (ip4);
 177   clib_bihash_kv_24_8_t kv, value;
 178   dslite_session_key_t key;
 179   u32 n = next;
 180   icmp_echo_header_t *echo;
 181   u32 new_addr, old_addr;
 182   u16 old_id, new_id;
 183   ip_csum_t sum;
 184
 185   if (icmp_type_is_error_message (icmp->type))
 186     {
 187       n = DSLITE_IN2OUT_NEXT_DROP;
 188       *error = DSLITE_ERROR_BAD_ICMP_TYPE;
 189       goto done;
 190     }
 191
 192   echo = (icmp_echo_header_t *) (icmp + 1);
 193
 194   key.addr = ip4->src_address;
 195   key.port = echo->identifier;
 196   key.proto = SNAT_PROTOCOL_ICMP;
 197   key.softwire_id.as_u64[0] = ip6->src_address.as_u64[0];
 198   key.softwire_id.as_u64[1] = ip6->src_address.as_u64[1];
 199   key.pad = 0;
 200   kv.key[0] = key.as_u64[0];
 201   kv.key[1] = key.as_u64[1];
 202   kv.key[2] = key.as_u64[2];
 203
 204   if (clib_bihash_search_24_8
 205       (&dm->per_thread_data[thread_index].in2out, &kv, &value))
 206     {
 207       n = slow_path (dm, &key, &s, next, error, thread_index);
 208       if (PREDICT_FALSE (next == DSLITE_IN2OUT_NEXT_DROP))
 209         goto done;
 210     }
 211   else
 212     {
 213       s =
 214         pool_elt_at_index (dm->per_thread_data[thread_index].sessions,
 215                            value.value);
 216     }
 217
 218   old_addr = ip4->src_address.as_u32;
 219   ip4->src_address = s->out2in.addr;
 220   new_addr = ip4->src_address.as_u32;
 221   sum = ip4->checksum;
 222   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, src_address);
 223   ip4->checksum = ip_csum_fold (sum);
 224
 225   old_id = echo->identifier;
 226   echo->identifier = new_id = s->out2in.port;
 227   sum = icmp->checksum;
 228   sum = ip_csum_update (sum, old_id, new_id, icmp_echo_header_t, identifier);
 229   icmp->checksum = ip_csum_fold (sum);
 230
 231 done:
 232   *sp = s;
 233   return n;
 234 }
 235
 236 static inline uword
 237 dslite_in2out_node_fn_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 238                               vlib_frame_t * frame, u8 is_slow_path)
 239 {
 240   u32 n_left_from, *from, *to_next;
 241   dslite_in2out_next_t next_index;
 242   u32 node_index;
 243   vlib_node_runtime_t *error_node;
 244   u32 thread_index = vm->thread_index;
 245   f64 now = vlib_time_now (vm);
 246   dslite_main_t *dm = &dslite_main;
 247
 248   node_index =
 249     is_slow_path ? dm->dslite_in2out_slowpath_node_index :
 250     dm->dslite_in2out_node_index;
 251
 252   error_node = vlib_node_get_runtime (vm, node_index);
 253
 254   from = vlib_frame_vector_args (frame);
 255   n_left_from = frame->n_vectors;
 256   next_index = node->cached_next_index;
 257
 258   while (n_left_from > 0)
 259     {
 260       u32 n_left_to_next;
 261
 262       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 263
 264       while (n_left_from > 0 && n_left_to_next > 0)
 265         {
 266           u32 bi0;
 267           vlib_buffer_t *b0;
 268           u32 next0 = DSLITE_IN2OUT_NEXT_IP4_LOOKUP;
 269           ip4_header_t *ip40;
 270           ip6_header_t *ip60;
 271           u8 error0 = DSLITE_ERROR_IN2OUT;
 272           u32 proto0;
 273           dslite_session_t *s0 = 0;
 274           clib_bihash_kv_24_8_t kv0, value0;
 275           dslite_session_key_t key0;
 276           udp_header_t *udp0;
 277           tcp_header_t *tcp0;
 278           ip_csum_t sum0;
 279           u32 new_addr0, old_addr0;
 280           u16 old_port0, new_port0;
 281
 282           /* speculatively enqueue b0 to the current next frame */
 283           bi0 = from[0];
 284           to_next[0] = bi0;
 285           from += 1;
 286           to_next += 1;
 287           n_left_from -= 1;
 288           n_left_to_next -= 1;
 289
 290           b0 = vlib_get_buffer (vm, bi0);
 291           ip60 = vlib_buffer_get_current (b0);
 292
 293           if (PREDICT_FALSE (ip60->protocol != IP_PROTOCOL_IP_IN_IP))
 294             {
 295               if (ip60->protocol == IP_PROTOCOL_ICMP6)
 296                 {
 297                   next0 = DSLITE_IN2OUT_NEXT_IP6_ICMP;
 298                   goto trace0;
 299                 }
 300               error0 = DSLITE_ERROR_BAD_IP6_PROTOCOL;
 301               next0 = DSLITE_IN2OUT_NEXT_DROP;
 302               goto trace0;
 303             }
 304
 305           ip40 = vlib_buffer_get_current (b0) + sizeof (ip6_header_t);
 306           proto0 = ip_proto_to_snat_proto (ip40->protocol);
 307
 308           if (PREDICT_FALSE (proto0 == ~0))
 309             {
 310               error0 = DSLITE_ERROR_UNSUPPORTED_PROTOCOL;
 311               next0 = DSLITE_IN2OUT_NEXT_DROP;
 312               goto trace0;
 313             }
 314
 315           udp0 = ip4_next_header (ip40);
 316           tcp0 = (tcp_header_t *) udp0;
 317
 318           if (is_slow_path)
 319             {
 320               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
 321                 {
 322                   next0 =
 323                     dslite_icmp_in2out (dm, ip60, ip40, &s0, next0, &error0,
 324                                         thread_index);
 325                   if (PREDICT_FALSE (next0 == DSLITE_IN2OUT_NEXT_DROP))
 326                     goto trace0;
 327
 328                   goto accounting0;
 329                 }
 330             }
 331           else
 332             {
 333               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
 334                 {
 335                   next0 = DSLITE_IN2OUT_NEXT_SLOWPATH;
 336                   goto trace0;
 337                 }
 338             }
 339
 340           key0.addr = ip40->src_address;
 341           key0.port = udp0->src_port;
 342           key0.proto = proto0;
 343           key0.softwire_id.as_u64[0] = ip60->src_address.as_u64[0];
 344           key0.softwire_id.as_u64[1] = ip60->src_address.as_u64[1];
 345           key0.pad = 0;
 346           kv0.key[0] = key0.as_u64[0];
 347           kv0.key[1] = key0.as_u64[1];
 348           kv0.key[2] = key0.as_u64[2];
 349
 350           if (clib_bihash_search_24_8
 351               (&dm->per_thread_data[thread_index].in2out, &kv0, &value0))
 352             {
 353               if (is_slow_path)
 354                 {
 355                   next0 =
 356                     slow_path (dm, &key0, &s0, next0, &error0, thread_index);
 357                   if (PREDICT_FALSE (next0 == DSLITE_IN2OUT_NEXT_DROP))
 358                     goto trace0;
 359                 }
 360               else
 361                 {
 362                   next0 = DSLITE_IN2OUT_NEXT_SLOWPATH;
 363                   goto trace0;
 364                 }
 365             }
 366           else
 367             {
 368               s0 =
 369                 pool_elt_at_index (dm->per_thread_data[thread_index].sessions,
 370                                    value0.value);
 371             }
 372
 373           old_addr0 = ip40->src_address.as_u32;
 374           ip40->src_address = s0->out2in.addr;
 375           new_addr0 = ip40->src_address.as_u32;
 376           sum0 = ip40->checksum;
 377           sum0 =
 378             ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 379                             src_address);
 380           ip40->checksum = ip_csum_fold (sum0);
 381           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
 382             {
 383               old_port0 = tcp0->src_port;
 384               tcp0->src_port = s0->out2in.port;
 385               new_port0 = tcp0->src_port;
 386
 387               sum0 = tcp0->checksum;
 388               sum0 =
 389                 ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 390                                 dst_address);
 391               sum0 =
 392                 ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 393                                 length);
 394               mss_clamping (&snat_main, tcp0, &sum0);
 395               tcp0->checksum = ip_csum_fold (sum0);
 396             }
 397           else
 398             {
 399               old_port0 = udp0->src_port;
 400               udp0->src_port = s0->out2in.port;
 401               udp0->checksum = 0;
 402             }
 403
 404         accounting0:
 405           /* Accounting */
 406           s0->last_heard = now;
 407           s0->total_pkts++;
 408           s0->total_bytes += vlib_buffer_length_in_chain (vm, b0);
 409           /* Per-B4 LRU list maintenance */
 410           clib_dlist_remove (dm->per_thread_data[thread_index].list_pool,
 411                              s0->per_b4_index);
 412           clib_dlist_addtail (dm->per_thread_data[thread_index].list_pool,
 413                               s0->per_b4_list_head_index, s0->per_b4_index);
 414
 415           ip40->tos =
 416             (clib_net_to_host_u32
 417              (ip60->ip_version_traffic_class_and_flow_label) & 0x0ff00000) >>
 418             20;
 419           vlib_buffer_advance (b0, sizeof (ip6_header_t));
 420
 421         trace0:
 422           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 423                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 424             {
 425               dslite_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
 426               t->next_index = next0;
 427               t->session_index = ~0;
 428               if (s0)
 429                 t->session_index =
 430                   s0 - dm->per_thread_data[thread_index].sessions;
 431             }
 432
 433           b0->error = error_node->errors[error0];
 434
 435           /* verify speculative enqueue, maybe switch current next frame */
 436           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 437                                            n_left_to_next, bi0, next0);
 438         }
 439       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 440     }
 441
 442   return frame->n_vectors;
 443 }
 444
 445 VLIB_NODE_FN (dslite_in2out_node) (vlib_main_t * vm,
 446                                    vlib_node_runtime_t * node,
 447                                    vlib_frame_t * frame)
 448 {
 449   return dslite_in2out_node_fn_inline (vm, node, frame, 0);
 450 }
 451
 452 /* *INDENT-OFF* */
 453 VLIB_REGISTER_NODE (dslite_in2out_node) = {
 454   .name = "dslite-in2out",
 455   .vector_size = sizeof (u32),
 456   .format_trace = format_dslite_trace,
 457   .type = VLIB_NODE_TYPE_INTERNAL,
 458   .n_errors = ARRAY_LEN (dslite_in2out_error_strings),
 459   .error_strings = dslite_in2out_error_strings,
 460   .n_next_nodes = DSLITE_IN2OUT_N_NEXT,
 461   /* edit / add dispositions here */
 462   .next_nodes = {
 463     [DSLITE_IN2OUT_NEXT_DROP] = "error-drop",
 464     [DSLITE_IN2OUT_NEXT_IP4_LOOKUP] = "ip4-lookup",
 465     [DSLITE_IN2OUT_NEXT_IP6_ICMP] = "ip6-icmp-input",
 466     [DSLITE_IN2OUT_NEXT_SLOWPATH] = "dslite-in2out-slowpath",
 467   },
 468 };
 469 /* *INDENT-ON* */
 470
 471 VLIB_NODE_FN (dslite_in2out_slowpath_node) (vlib_main_t * vm,
 472                                             vlib_node_runtime_t * node,
 473                                             vlib_frame_t * frame)
 474 {
 475   return dslite_in2out_node_fn_inline (vm, node, frame, 1);
 476 }
 477
 478 /* *INDENT-OFF* */
 479 VLIB_REGISTER_NODE (dslite_in2out_slowpath_node) = {
 480   .name = "dslite-in2out-slowpath",
 481   .vector_size = sizeof (u32),
 482   .format_trace = format_dslite_trace,
 483   .type = VLIB_NODE_TYPE_INTERNAL,
 484   .n_errors = ARRAY_LEN (dslite_in2out_error_strings),
 485   .error_strings = dslite_in2out_error_strings,
 486   .n_next_nodes = DSLITE_IN2OUT_N_NEXT,
 487   /* edit / add dispositions here */
 488   .next_nodes = {
 489     [DSLITE_IN2OUT_NEXT_DROP] = "error-drop",
 490     [DSLITE_IN2OUT_NEXT_IP4_LOOKUP] = "ip4-lookup",
 491     [DSLITE_IN2OUT_NEXT_IP6_ICMP] = "ip6-lookup",
 492     [DSLITE_IN2OUT_NEXT_SLOWPATH] = "dslite-in2out-slowpath",
 493   },
 494 };
 495 /* *INDENT-ON* */
 496
 497 /*
 498  * fd.io coding-style-patch-verification: ON
 499  *
 500  * Local Variables:
 501  * eval: (c-set-style "gnu")
 502  * End:
 503  */