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
  17 vlib_node_registration_t dslite_in2out_node;
  18 vlib_node_registration_t dslite_in2out_slowpath_node;
  19
  20 typedef enum
  21 {
  22   DSLITE_IN2OUT_NEXT_IP4_LOOKUP,
  23   DSLITE_IN2OUT_NEXT_IP6_LOOKUP,
  24   DSLITE_IN2OUT_NEXT_DROP,
  25   DSLITE_IN2OUT_NEXT_SLOWPATH,
  26   DSLITE_IN2OUT_N_NEXT,
  27 } dslite_in2out_next_t;
  28
  29 static char *dslite_in2out_error_strings[] = {
  30 #define _(sym,string) string,
  31   foreach_dslite_error
  32 #undef _
  33 };
  34
  35 static u32
  36 slow_path (dslite_main_t * dm, dslite_session_key_t * in2out_key,
  37            dslite_session_t ** sp, u32 next, u8 * error, u32 thread_index)
  38 {
  39   dslite_b4_t *b4;
  40   clib_bihash_kv_16_8_t b4_kv, b4_value;
  41   clib_bihash_kv_24_8_t in2out_kv;
  42   clib_bihash_kv_8_8_t out2in_kv;
  43   dlist_elt_t *head_elt, *oldest_elt, *elt;
  44   u32 oldest_index;
  45   dslite_session_t *s;
  46   snat_session_key_t out2in_key;
  47   u32 address_index;
  48
  49   out2in_key.protocol = in2out_key->proto;
  50   out2in_key.fib_index = 0;
  51
  52   b4_kv.key[0] = in2out_key->softwire_id.as_u64[0];
  53   b4_kv.key[1] = in2out_key->softwire_id.as_u64[1];
  54
  55   if (clib_bihash_search_16_8
  56       (&dm->per_thread_data[thread_index].b4_hash, &b4_kv, &b4_value))
  57     {
  58       pool_get (dm->per_thread_data[thread_index].b4s, b4);
  59       memset (b4, 0, sizeof (*b4));
  60       b4->addr.as_u64[0] = in2out_key->softwire_id.as_u64[0];
  61       b4->addr.as_u64[1] = in2out_key->softwire_id.as_u64[1];
  62
  63       pool_get (dm->per_thread_data[thread_index].list_pool, head_elt);
  64       b4->sessions_per_b4_list_head_index =
  65         head_elt - dm->per_thread_data[thread_index].list_pool;
  66       clib_dlist_init (dm->per_thread_data[thread_index].list_pool,
  67                        b4->sessions_per_b4_list_head_index);
  68
  69       b4_kv.value = b4 - dm->per_thread_data[thread_index].b4s;
  70       clib_bihash_add_del_16_8 (&dm->per_thread_data[thread_index].b4_hash,
  71                                 &b4_kv, 1);
  72     }
  73   else
  74     {
  75       b4 =
  76         pool_elt_at_index (dm->per_thread_data[thread_index].b4s,
  77                            b4_value.value);
  78     }
  79
  80   //TODO configurable quota
  81   if (b4->nsessions >= 1000)
  82     {
  83       oldest_index =
  84         clib_dlist_remove_head (dm->per_thread_data[thread_index].list_pool,
  85                                 b4->sessions_per_b4_list_head_index);
  86       ASSERT (oldest_index != ~0);
  87       clib_dlist_addtail (dm->per_thread_data[thread_index].list_pool,
  88                           b4->sessions_per_b4_list_head_index, oldest_index);
  89       oldest_elt =
  90         pool_elt_at_index (dm->per_thread_data[thread_index].list_pool,
  91                            oldest_index);
  92       s =
  93         pool_elt_at_index (dm->per_thread_data[thread_index].sessions,
  94                            oldest_elt->value);
  95
  96       in2out_kv.key[0] = s->in2out.as_u64[0];
  97       in2out_kv.key[1] = s->in2out.as_u64[1];
  98       in2out_kv.key[2] = s->in2out.as_u64[2];
  99       clib_bihash_add_del_24_8 (&dm->per_thread_data[thread_index].in2out,
 100                                 &in2out_kv, 0);
 101       out2in_kv.key = s->out2in.as_u64;
 102       clib_bihash_add_del_8_8 (&dm->per_thread_data[thread_index].out2in,
 103                                &out2in_kv, 0);
 104       snat_free_outside_address_and_port (dm->addr_pool, thread_index,
 105                                           &s->out2in,
 106                                           s->outside_address_index);
 107       s->outside_address_index = ~0;
 108
 109       if (snat_alloc_outside_address_and_port
 110           (dm->addr_pool, 0, thread_index, &out2in_key,
 111            &s->outside_address_index, 0, dm->port_per_thread, thread_index))
 112         ASSERT (0);
 113     }
 114   else
 115     {
 116       if (snat_alloc_outside_address_and_port
 117           (dm->addr_pool, 0, thread_index, &out2in_key, &address_index, 0,
 118            dm->port_per_thread, thread_index))
 119         {
 120           *error = DSLITE_ERROR_OUT_OF_PORTS;
 121           return DSLITE_IN2OUT_NEXT_DROP;
 122         }
 123       pool_get (dm->per_thread_data[thread_index].sessions, s);
 124       memset (s, 0, sizeof (*s));
 125       s->outside_address_index = address_index;
 126       b4->nsessions++;
 127
 128       pool_get (dm->per_thread_data[thread_index].list_pool, elt);
 129       clib_dlist_init (dm->per_thread_data[thread_index].list_pool,
 130                        elt - dm->per_thread_data[thread_index].list_pool);
 131       elt->value = s - dm->per_thread_data[thread_index].sessions;
 132       s->per_b4_index = elt - dm->per_thread_data[thread_index].list_pool;
 133       s->per_b4_list_head_index = b4->sessions_per_b4_list_head_index;
 134       clib_dlist_addtail (dm->per_thread_data[thread_index].list_pool,
 135                           s->per_b4_list_head_index,
 136                           elt - dm->per_thread_data[thread_index].list_pool);
 137     }
 138
 139   s->in2out = *in2out_key;
 140   s->out2in = out2in_key;
 141   *sp = s;
 142   in2out_kv.key[0] = s->in2out.as_u64[0];
 143   in2out_kv.key[1] = s->in2out.as_u64[1];
 144   in2out_kv.key[2] = s->in2out.as_u64[2];
 145   in2out_kv.value = s - dm->per_thread_data[thread_index].sessions;
 146   clib_bihash_add_del_24_8 (&dm->per_thread_data[thread_index].in2out,
 147                             &in2out_kv, 1);
 148   out2in_kv.key = s->out2in.as_u64;
 149   out2in_kv.value = s - dm->per_thread_data[thread_index].sessions;
 150   clib_bihash_add_del_8_8 (&dm->per_thread_data[thread_index].out2in,
 151                            &out2in_kv, 1);
 152
 153   return next;
 154 }
 155
 156 static inline u32
 157 dslite_icmp_in2out (dslite_main_t * dm, ip6_header_t * ip6,
 158                     ip4_header_t * ip4, dslite_session_t ** sp, u32 next,
 159                     u8 * error, u32 thread_index)
 160 {
 161   dslite_session_t *s = 0;
 162   icmp46_header_t *icmp = ip4_next_header (ip4);
 163   clib_bihash_kv_24_8_t kv, value;
 164   dslite_session_key_t key;
 165   u32 n = next;
 166   icmp_echo_header_t *echo;
 167   u32 new_addr, old_addr;
 168   u16 old_id, new_id;
 169   ip_csum_t sum;
 170
 171   if (icmp_is_error_message (icmp))
 172     {
 173       n = DSLITE_IN2OUT_NEXT_DROP;
 174       *error = DSLITE_ERROR_BAD_ICMP_TYPE;
 175       goto done;
 176     }
 177
 178   echo = (icmp_echo_header_t *) (icmp + 1);
 179
 180   key.addr = ip4->src_address;
 181   key.port = echo->identifier;
 182   key.proto = SNAT_PROTOCOL_ICMP;
 183   key.softwire_id.as_u64[0] = ip6->src_address.as_u64[0];
 184   key.softwire_id.as_u64[1] = ip6->src_address.as_u64[1];
 185   key.pad = 0;
 186   kv.key[0] = key.as_u64[0];
 187   kv.key[1] = key.as_u64[1];
 188   kv.key[2] = key.as_u64[2];
 189
 190   if (clib_bihash_search_24_8
 191       (&dm->per_thread_data[thread_index].in2out, &kv, &value))
 192     {
 193       n = slow_path (dm, &key, &s, next, error, thread_index);
 194       if (PREDICT_FALSE (next == DSLITE_IN2OUT_NEXT_DROP))
 195         goto done;
 196     }
 197   else
 198     {
 199       s =
 200         pool_elt_at_index (dm->per_thread_data[thread_index].sessions,
 201                            value.value);
 202     }
 203
 204   old_addr = ip4->src_address.as_u32;
 205   ip4->src_address = s->out2in.addr;
 206   new_addr = ip4->src_address.as_u32;
 207   sum = ip4->checksum;
 208   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, src_address);
 209   ip4->checksum = ip_csum_fold (sum);
 210
 211   old_id = echo->identifier;
 212   echo->identifier = new_id = s->out2in.port;
 213   sum = icmp->checksum;
 214   sum = ip_csum_update (sum, old_id, new_id, icmp_echo_header_t, identifier);
 215   icmp->checksum = ip_csum_fold (sum);
 216
 217 done:
 218   *sp = s;
 219   return n;
 220 }
 221
 222 static inline uword
 223 dslite_in2out_node_fn_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 224                               vlib_frame_t * frame, u8 is_slow_path)
 225 {
 226   u32 n_left_from, *from, *to_next;
 227   dslite_in2out_next_t next_index;
 228   u32 node_index;
 229   vlib_node_runtime_t *error_node;
 230   u32 thread_index = vlib_get_thread_index ();
 231   f64 now = vlib_time_now (vm);
 232   dslite_main_t *dm = &dslite_main;
 233
 234   node_index =
 235     is_slow_path ? dslite_in2out_slowpath_node.
 236     index : dslite_in2out_node.index;
 237
 238   error_node = vlib_node_get_runtime (vm, node_index);
 239
 240   from = vlib_frame_vector_args (frame);
 241   n_left_from = frame->n_vectors;
 242   next_index = node->cached_next_index;
 243
 244   while (n_left_from > 0)
 245     {
 246       u32 n_left_to_next;
 247
 248       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 249
 250       while (n_left_from > 0 && n_left_to_next > 0)
 251         {
 252           u32 bi0;
 253           vlib_buffer_t *b0;
 254           u32 next0 = DSLITE_IN2OUT_NEXT_IP4_LOOKUP;
 255           ip4_header_t *ip40;
 256           ip6_header_t *ip60;
 257           u8 error0 = DSLITE_ERROR_IN2OUT;
 258           u32 proto0;
 259           dslite_session_t *s0 = 0;
 260           clib_bihash_kv_24_8_t kv0, value0;
 261           dslite_session_key_t key0;
 262           udp_header_t *udp0;
 263           tcp_header_t *tcp0;
 264           ip_csum_t sum0;
 265           u32 new_addr0, old_addr0;
 266           u16 old_port0, new_port0;
 267
 268           /* speculatively enqueue b0 to the current next frame */
 269           bi0 = from[0];
 270           to_next[0] = bi0;
 271           from += 1;
 272           to_next += 1;
 273           n_left_from -= 1;
 274           n_left_to_next -= 1;
 275
 276           b0 = vlib_get_buffer (vm, bi0);
 277           ip60 = vlib_buffer_get_current (b0);
 278
 279           if (PREDICT_FALSE (ip60->protocol != IP_PROTOCOL_IP_IN_IP))
 280             {
 281               error0 = DSLITE_ERROR_BAD_IP6_PROTOCOL;
 282               next0 = DSLITE_IN2OUT_NEXT_DROP;
 283               goto trace0;
 284             }
 285
 286           ip40 = vlib_buffer_get_current (b0) + sizeof (ip6_header_t);
 287           proto0 = ip_proto_to_snat_proto (ip40->protocol);
 288
 289           if (PREDICT_FALSE (proto0 == ~0))
 290             {
 291               error0 = DSLITE_ERROR_UNSUPPORTED_PROTOCOL;
 292               next0 = DSLITE_IN2OUT_NEXT_DROP;
 293               goto trace0;
 294             }
 295
 296           udp0 = ip4_next_header (ip40);
 297           tcp0 = (tcp_header_t *) udp0;
 298
 299           if (is_slow_path)
 300             {
 301               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
 302                 {
 303                   next0 =
 304                     dslite_icmp_in2out (dm, ip60, ip40, &s0, next0, &error0,
 305                                         thread_index);
 306                   if (PREDICT_FALSE (next0 == DSLITE_IN2OUT_NEXT_DROP))
 307                     goto trace0;
 308
 309                   goto accounting0;
 310                 }
 311             }
 312           else
 313             {
 314               if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
 315                 {
 316                   next0 = DSLITE_IN2OUT_NEXT_SLOWPATH;
 317                   goto trace0;
 318                 }
 319             }
 320
 321           key0.addr = ip40->src_address;
 322           key0.port = udp0->src_port;
 323           key0.proto = proto0;
 324           key0.softwire_id.as_u64[0] = ip60->src_address.as_u64[0];
 325           key0.softwire_id.as_u64[1] = ip60->src_address.as_u64[1];
 326           key0.pad = 0;
 327           kv0.key[0] = key0.as_u64[0];
 328           kv0.key[1] = key0.as_u64[1];
 329           kv0.key[2] = key0.as_u64[2];
 330
 331           if (clib_bihash_search_24_8
 332               (&dm->per_thread_data[thread_index].in2out, &kv0, &value0))
 333             {
 334               if (is_slow_path)
 335                 {
 336                   next0 =
 337                     slow_path (dm, &key0, &s0, next0, &error0, thread_index);
 338                   if (PREDICT_FALSE (next0 == DSLITE_IN2OUT_NEXT_DROP))
 339                     goto trace0;
 340                 }
 341               else
 342                 {
 343                   next0 = DSLITE_IN2OUT_NEXT_SLOWPATH;
 344                   goto trace0;
 345                 }
 346             }
 347           else
 348             {
 349               s0 =
 350                 pool_elt_at_index (dm->per_thread_data[thread_index].sessions,
 351                                    value0.value);
 352             }
 353
 354           old_addr0 = ip40->src_address.as_u32;
 355           ip40->src_address = s0->out2in.addr;
 356           new_addr0 = ip40->src_address.as_u32;
 357           sum0 = ip40->checksum;
 358           sum0 =
 359             ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 360                             src_address);
 361           ip40->checksum = ip_csum_fold (sum0);
 362           if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
 363             {
 364               old_port0 = tcp0->src_port;
 365               tcp0->src_port = s0->out2in.port;
 366               new_port0 = tcp0->src_port;
 367
 368               sum0 = tcp0->checksum;
 369               sum0 =
 370                 ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 371                                 dst_address);
 372               sum0 =
 373                 ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 374                                 length);
 375               tcp0->checksum = ip_csum_fold (sum0);
 376             }
 377           else
 378             {
 379               old_port0 = udp0->src_port;
 380               udp0->src_port = s0->out2in.port;
 381               udp0->checksum = 0;
 382             }
 383
 384         accounting0:
 385           /* Accounting */
 386           s0->last_heard = now;
 387           s0->total_pkts++;
 388           s0->total_bytes += vlib_buffer_length_in_chain (vm, b0);
 389           /* Per-B4 LRU list maintenance */
 390           clib_dlist_remove (dm->per_thread_data[thread_index].list_pool,
 391                              s0->per_b4_index);
 392           clib_dlist_addtail (dm->per_thread_data[thread_index].list_pool,
 393                               s0->per_b4_list_head_index, s0->per_b4_index);
 394
 395           ip40->tos =
 396             (clib_net_to_host_u32
 397              (ip60->ip_version_traffic_class_and_flow_label) & 0x0ff00000) >>
 398             20;
 399           vlib_buffer_advance (b0, sizeof (ip6_header_t));
 400
 401         trace0:
 402           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 403                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 404             {
 405               dslite_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
 406               t->next_index = next0;
 407               t->session_index = ~0;
 408               if (s0)
 409                 t->session_index =
 410                   s0 - dm->per_thread_data[thread_index].sessions;
 411             }
 412
 413           b0->error = error_node->errors[error0];
 414
 415           /* verify speculative enqueue, maybe switch current next frame */
 416           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 417                                            n_left_to_next, bi0, next0);
 418         }
 419       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 420     }
 421
 422   return frame->n_vectors;
 423 }
 424
 425 static uword
 426 dslite_in2out_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 427                        vlib_frame_t * frame)
 428 {
 429   return dslite_in2out_node_fn_inline (vm, node, frame, 0);
 430 }
 431
 432 /* *INDENT-OFF* */
 433 VLIB_REGISTER_NODE (dslite_in2out_node) = {
 434   .function = dslite_in2out_node_fn,
 435   .name = "dslite-in2out",
 436   .vector_size = sizeof (u32),
 437   .format_trace = format_dslite_trace,
 438   .type = VLIB_NODE_TYPE_INTERNAL,
 439   .n_errors = ARRAY_LEN (dslite_in2out_error_strings),
 440   .error_strings = dslite_in2out_error_strings,
 441   .n_next_nodes = DSLITE_IN2OUT_N_NEXT,
 442   /* edit / add dispositions here */
 443   .next_nodes = {
 444     [DSLITE_IN2OUT_NEXT_DROP] = "error-drop",
 445     [DSLITE_IN2OUT_NEXT_IP4_LOOKUP] = "ip4-lookup",
 446     [DSLITE_IN2OUT_NEXT_IP6_LOOKUP] = "ip6-lookup",
 447     [DSLITE_IN2OUT_NEXT_SLOWPATH] = "dslite-in2out-slowpath",
 448   },
 449 };
 450 /* *INDENT-ON* */
 451
 452 VLIB_NODE_FUNCTION_MULTIARCH (dslite_in2out_node, dslite_in2out_node_fn);
 453
 454 static uword
 455 dslite_in2out_slowpath_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 456                                 vlib_frame_t * frame)
 457 {
 458   return dslite_in2out_node_fn_inline (vm, node, frame, 1);
 459 }
 460
 461 /* *INDENT-OFF* */
 462 VLIB_REGISTER_NODE (dslite_in2out_slowpath_node) = {
 463   .function = dslite_in2out_slowpath_node_fn,
 464   .name = "dslite-in2out-slowpath",
 465   .vector_size = sizeof (u32),
 466   .format_trace = format_dslite_trace,
 467   .type = VLIB_NODE_TYPE_INTERNAL,
 468   .n_errors = ARRAY_LEN (dslite_in2out_error_strings),
 469   .error_strings = dslite_in2out_error_strings,
 470   .n_next_nodes = DSLITE_IN2OUT_N_NEXT,
 471   /* edit / add dispositions here */
 472   .next_nodes = {
 473     [DSLITE_IN2OUT_NEXT_DROP] = "error-drop",
 474     [DSLITE_IN2OUT_NEXT_IP4_LOOKUP] = "ip4-lookup",
 475     [DSLITE_IN2OUT_NEXT_IP6_LOOKUP] = "ip6-lookup",
 476     [DSLITE_IN2OUT_NEXT_SLOWPATH] = "dslite-in2out-slowpath",
 477   },
 478 };
 479 /* *INDENT-ON* */
 480
 481 VLIB_NODE_FUNCTION_MULTIARCH (dslite_in2out_slowpath_node,
 482                               dslite_in2out_slowpath_node_fn);
 483
 484 /*
 485  * fd.io coding-style-patch-verification: ON
 486  *
 487  * Local Variables:
 488  * eval: (c-set-style "gnu")
 489  * End:
 490  */