src/plugins/nat/dslite/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/dslite.h>
  16 #include <nat/lib/nat_syslog.h>
  17
  18 typedef enum
  19 {
  20   DSLITE_IN2OUT_NEXT_IP4_LOOKUP,
  21   DSLITE_IN2OUT_NEXT_IP6_ICMP,
  22   DSLITE_IN2OUT_NEXT_DROP,
  23   DSLITE_IN2OUT_NEXT_SLOWPATH,
  24   DSLITE_IN2OUT_N_NEXT,
  25 } dslite_in2out_next_t;
  26
  27 static char *dslite_in2out_error_strings[] = {
  28 #define _(sym,string) string,
  29   foreach_dslite_error
  30 #undef _
  31 };
  32
  33 static u32
  34 slow_path (dslite_main_t * dm, dslite_session_key_t * in2out_key,
  35            dslite_session_t ** sp, u32 next, u8 * error, u32 thread_index)
  36 {
  37   dslite_b4_t *b4;
  38   clib_bihash_kv_16_8_t b4_kv, b4_value;
  39   clib_bihash_kv_24_8_t in2out_kv;
  40   clib_bihash_kv_8_8_t out2in_kv;
  41   dlist_elt_t *head_elt, *oldest_elt, *elt;
  42   u32 oldest_index;
  43   dslite_session_t *s;
  44   nat_session_key_t out2in_key;
  45   nat_ip4_addr_port_t addr_port;
  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
 109       addr_port.addr.as_u32 = s->out2in.addr.as_u32;
 110       addr_port.port = s->out2in.port;
 111
 112       nat_free_ip4_addr_and_port (&dm->pool, thread_index,
 113                                   s->out2in.protocol, &addr_port);
 114
 115       nat_syslog_dslite_apmdel (b4_index, &s->in2out.softwire_id,
 116                                 &s->in2out.addr, s->in2out.port,
 117                                 &s->out2in.addr, s->out2in.port,
 118                                 s->in2out.proto);
 119
 120       if (nat_alloc_ip4_addr_and_port
 121           (&dm->pool, 0, thread_index, thread_index,
 122            dm->port_per_thread, out2in_key.protocol, &addr_port))
 123         ASSERT (0);
 124
 125       out2in_key.addr.as_u32 = addr_port.addr.as_u32;
 126       out2in_key.port = addr_port.port;
 127     }
 128   else
 129     {
 130       if (nat_alloc_ip4_addr_and_port
 131           (&dm->pool, 0, thread_index, thread_index,
 132            dm->port_per_thread, out2in_key.protocol, &addr_port))
 133         {
 134           *error = DSLITE_ERROR_OUT_OF_PORTS;
 135           return DSLITE_IN2OUT_NEXT_DROP;
 136         }
 137
 138       out2in_key.addr.as_u32 = addr_port.addr.as_u32;
 139       out2in_key.port = addr_port.port;
 140
 141       pool_get (dm->per_thread_data[thread_index].sessions, s);
 142       clib_memset (s, 0, sizeof (*s));
 143       b4->nsessions++;
 144
 145       pool_get (dm->per_thread_data[thread_index].list_pool, elt);
 146       clib_dlist_init (dm->per_thread_data[thread_index].list_pool,
 147                        elt - dm->per_thread_data[thread_index].list_pool);
 148       elt->value = s - dm->per_thread_data[thread_index].sessions;
 149       s->per_b4_index = elt - dm->per_thread_data[thread_index].list_pool;
 150       s->per_b4_list_head_index = b4->sessions_per_b4_list_head_index;
 151       clib_dlist_addtail (dm->per_thread_data[thread_index].list_pool,
 152                           s->per_b4_list_head_index,
 153                           elt - dm->per_thread_data[thread_index].list_pool);
 154
 155       vlib_set_simple_counter (&dm->total_sessions, thread_index, 0,
 156                                pool_elts (dm->per_thread_data
 157                                           [thread_index].sessions));
 158     }
 159
 160   s->in2out = *in2out_key;
 161   s->out2in = out2in_key;
 162   *sp = s;
 163   in2out_kv.key[0] = s->in2out.as_u64[0];
 164   in2out_kv.key[1] = s->in2out.as_u64[1];
 165   in2out_kv.key[2] = s->in2out.as_u64[2];
 166   in2out_kv.value = s - dm->per_thread_data[thread_index].sessions;
 167   clib_bihash_add_del_24_8 (&dm->per_thread_data[thread_index].in2out,
 168                             &in2out_kv, 1);
 169   out2in_kv.key = s->out2in.as_u64;
 170   out2in_kv.value = s - dm->per_thread_data[thread_index].sessions;
 171   clib_bihash_add_del_8_8 (&dm->per_thread_data[thread_index].out2in,
 172                            &out2in_kv, 1);
 173
 174   nat_syslog_dslite_apmadd (b4_index, &s->in2out.softwire_id, &s->in2out.addr,
 175                             s->in2out.port, &s->out2in.addr, s->out2in.port,
 176                             s->in2out.proto);
 177
 178   return next;
 179 }
 180
 181 static inline u32
 182 dslite_icmp_in2out (dslite_main_t * dm, ip6_header_t * ip6,
 183                     ip4_header_t * ip4, dslite_session_t ** sp, u32 next,
 184                     u8 * error, u32 thread_index)
 185 {
 186   dslite_session_t *s = 0;
 187   icmp46_header_t *icmp = ip4_next_header (ip4);
 188   clib_bihash_kv_24_8_t kv, value;
 189   dslite_session_key_t key;
 190   u32 n = next;
 191   echo_header_t *echo;
 192   u32 new_addr, old_addr;
 193   u16 old_id, new_id;
 194   ip_csum_t sum;
 195
 196   if (icmp_type_is_error_message (icmp->type))
 197     {
 198       n = DSLITE_IN2OUT_NEXT_DROP;
 199       *error = DSLITE_ERROR_BAD_ICMP_TYPE;
 200       goto done;
 201     }
 202
 203   echo = (echo_header_t *) (icmp + 1);
 204
 205   key.addr = ip4->src_address;
 206   key.port = echo->identifier;
 207   key.proto = NAT_PROTOCOL_ICMP;
 208   key.softwire_id.as_u64[0] = ip6->src_address.as_u64[0];
 209   key.softwire_id.as_u64[1] = ip6->src_address.as_u64[1];
 210   key.pad = 0;
 211   kv.key[0] = key.as_u64[0];
 212   kv.key[1] = key.as_u64[1];
 213   kv.key[2] = key.as_u64[2];
 214
 215   if (clib_bihash_search_24_8
 216       (&dm->per_thread_data[thread_index].in2out, &kv, &value))
 217     {
 218       n = slow_path (dm, &key, &s, next, error, thread_index);
 219       if (PREDICT_FALSE (next == DSLITE_IN2OUT_NEXT_DROP))
 220         goto done;
 221     }
 222   else
 223     {
 224       s =
 225         pool_elt_at_index (dm->per_thread_data[thread_index].sessions,
 226                            value.value);
 227     }
 228
 229   old_addr = ip4->src_address.as_u32;
 230   ip4->src_address = s->out2in.addr;
 231   new_addr = ip4->src_address.as_u32;
 232   sum = ip4->checksum;
 233   sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, src_address);
 234   ip4->checksum = ip_csum_fold (sum);
 235
 236   old_id = echo->identifier;
 237   echo->identifier = new_id = s->out2in.port;
 238   sum = icmp->checksum;
 239   sum = ip_csum_update (sum, old_id, new_id, echo_header_t, identifier);
 240   icmp->checksum = ip_csum_fold (sum);
 241
 242 done:
 243   *sp = s;
 244   return n;
 245 }
 246
 247 static inline uword
 248 dslite_in2out_node_fn_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 249                               vlib_frame_t * frame, u8 is_slow_path)
 250 {
 251   u32 n_left_from, *from, *to_next;
 252   dslite_in2out_next_t next_index;
 253   u32 node_index;
 254   vlib_node_runtime_t *error_node;
 255   u32 thread_index = vm->thread_index;
 256   f64 now = vlib_time_now (vm);
 257   dslite_main_t *dm = &dslite_main;
 258
 259   node_index =
 260     is_slow_path ? dm->dslite_in2out_slowpath_node_index :
 261     dm->dslite_in2out_node_index;
 262
 263   error_node = vlib_node_get_runtime (vm, node_index);
 264
 265   from = vlib_frame_vector_args (frame);
 266   n_left_from = frame->n_vectors;
 267   next_index = node->cached_next_index;
 268
 269   while (n_left_from > 0)
 270     {
 271       u32 n_left_to_next;
 272
 273       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 274
 275       while (n_left_from > 0 && n_left_to_next > 0)
 276         {
 277           u32 bi0;
 278           vlib_buffer_t *b0;
 279           u32 next0 = DSLITE_IN2OUT_NEXT_IP4_LOOKUP;
 280           ip4_header_t *ip40;
 281           ip6_header_t *ip60;
 282           u8 error0 = DSLITE_ERROR_IN2OUT;
 283           u32 proto0;
 284           dslite_session_t *s0 = 0;
 285           clib_bihash_kv_24_8_t kv0, value0;
 286           dslite_session_key_t key0;
 287           udp_header_t *udp0;
 288           tcp_header_t *tcp0;
 289           ip_csum_t sum0;
 290           u32 new_addr0, old_addr0;
 291           u16 old_port0, new_port0;
 292
 293           /* speculatively enqueue b0 to the current next frame */
 294           bi0 = from[0];
 295           to_next[0] = bi0;
 296           from += 1;
 297           to_next += 1;
 298           n_left_from -= 1;
 299           n_left_to_next -= 1;
 300
 301           b0 = vlib_get_buffer (vm, bi0);
 302           ip60 = vlib_buffer_get_current (b0);
 303
 304           if (PREDICT_FALSE (ip60->protocol != IP_PROTOCOL_IP_IN_IP))
 305             {
 306               if (ip60->protocol == IP_PROTOCOL_ICMP6)
 307                 {
 308                   next0 = DSLITE_IN2OUT_NEXT_IP6_ICMP;
 309                   goto trace0;
 310                 }
 311               error0 = DSLITE_ERROR_BAD_IP6_PROTOCOL;
 312               next0 = DSLITE_IN2OUT_NEXT_DROP;
 313               goto trace0;
 314             }
 315
 316           ip40 = vlib_buffer_get_current (b0) + sizeof (ip6_header_t);
 317           proto0 = ip_proto_to_nat_proto (ip40->protocol);
 318
 319           if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
 320             {
 321               error0 = DSLITE_ERROR_UNSUPPORTED_PROTOCOL;
 322               next0 = DSLITE_IN2OUT_NEXT_DROP;
 323               goto trace0;
 324             }
 325
 326           udp0 = ip4_next_header (ip40);
 327           tcp0 = (tcp_header_t *) udp0;
 328
 329           if (is_slow_path)
 330             {
 331               if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
 332                 {
 333                   next0 =
 334                     dslite_icmp_in2out (dm, ip60, ip40, &s0, next0, &error0,
 335                                         thread_index);
 336                   if (PREDICT_FALSE (next0 == DSLITE_IN2OUT_NEXT_DROP))
 337                     goto trace0;
 338
 339                   goto accounting0;
 340                 }
 341             }
 342           else
 343             {
 344               if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
 345                 {
 346                   next0 = DSLITE_IN2OUT_NEXT_SLOWPATH;
 347                   goto trace0;
 348                 }
 349             }
 350
 351           key0.addr = ip40->src_address;
 352           key0.port = udp0->src_port;
 353           key0.proto = proto0;
 354           key0.softwire_id.as_u64[0] = ip60->src_address.as_u64[0];
 355           key0.softwire_id.as_u64[1] = ip60->src_address.as_u64[1];
 356           key0.pad = 0;
 357           kv0.key[0] = key0.as_u64[0];
 358           kv0.key[1] = key0.as_u64[1];
 359           kv0.key[2] = key0.as_u64[2];
 360
 361           if (clib_bihash_search_24_8
 362               (&dm->per_thread_data[thread_index].in2out, &kv0, &value0))
 363             {
 364               if (is_slow_path)
 365                 {
 366                   next0 =
 367                     slow_path (dm, &key0, &s0, next0, &error0, thread_index);
 368                   if (PREDICT_FALSE (next0 == DSLITE_IN2OUT_NEXT_DROP))
 369                     goto trace0;
 370                 }
 371               else
 372                 {
 373                   next0 = DSLITE_IN2OUT_NEXT_SLOWPATH;
 374                   goto trace0;
 375                 }
 376             }
 377           else
 378             {
 379               s0 =
 380                 pool_elt_at_index (dm->per_thread_data[thread_index].sessions,
 381                                    value0.value);
 382             }
 383
 384           old_addr0 = ip40->src_address.as_u32;
 385           ip40->src_address = s0->out2in.addr;
 386           new_addr0 = ip40->src_address.as_u32;
 387           sum0 = ip40->checksum;
 388           sum0 =
 389             ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 390                             src_address);
 391           ip40->checksum = ip_csum_fold (sum0);
 392           if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
 393             {
 394               old_port0 = tcp0->src_port;
 395               tcp0->src_port = s0->out2in.port;
 396               new_port0 = tcp0->src_port;
 397
 398               sum0 = tcp0->checksum;
 399               sum0 =
 400                 ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
 401                                 dst_address);
 402               sum0 =
 403                 ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
 404                                 length);
 405               //mss_clamping (&dslite_main, tcp0, &sum0);
 406               tcp0->checksum = ip_csum_fold (sum0);
 407             }
 408           else
 409             {
 410               old_port0 = udp0->src_port;
 411               udp0->src_port = s0->out2in.port;
 412               udp0->checksum = 0;
 413             }
 414
 415         accounting0:
 416           /* Accounting */
 417           s0->last_heard = now;
 418           s0->total_pkts++;
 419           s0->total_bytes += vlib_buffer_length_in_chain (vm, b0);
 420           /* Per-B4 LRU list maintenance */
 421           clib_dlist_remove (dm->per_thread_data[thread_index].list_pool,
 422                              s0->per_b4_index);
 423           clib_dlist_addtail (dm->per_thread_data[thread_index].list_pool,
 424                               s0->per_b4_list_head_index, s0->per_b4_index);
 425
 426           ip40->tos =
 427             (clib_net_to_host_u32
 428              (ip60->ip_version_traffic_class_and_flow_label) & 0x0ff00000) >>
 429             20;
 430           vlib_buffer_advance (b0, sizeof (ip6_header_t));
 431
 432         trace0:
 433           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 434                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 435             {
 436               dslite_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
 437               t->next_index = next0;
 438               t->session_index = ~0;
 439               if (s0)
 440                 t->session_index =
 441                   s0 - dm->per_thread_data[thread_index].sessions;
 442             }
 443
 444           b0->error = error_node->errors[error0];
 445
 446           /* verify speculative enqueue, maybe switch current next frame */
 447           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 448                                            n_left_to_next, bi0, next0);
 449         }
 450       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 451     }
 452
 453   return frame->n_vectors;
 454 }
 455
 456 VLIB_NODE_FN (dslite_in2out_node) (vlib_main_t * vm,
 457                                    vlib_node_runtime_t * node,
 458                                    vlib_frame_t * frame)
 459 {
 460   return dslite_in2out_node_fn_inline (vm, node, frame, 0);
 461 }
 462
 463 /* *INDENT-OFF* */
 464 VLIB_REGISTER_NODE (dslite_in2out_node) = {
 465   .name = "dslite-in2out",
 466   .vector_size = sizeof (u32),
 467   .format_trace = format_dslite_trace,
 468   .type = VLIB_NODE_TYPE_INTERNAL,
 469   .n_errors = ARRAY_LEN (dslite_in2out_error_strings),
 470   .error_strings = dslite_in2out_error_strings,
 471   .n_next_nodes = DSLITE_IN2OUT_N_NEXT,
 472   /* edit / add dispositions here */
 473   .next_nodes = {
 474     [DSLITE_IN2OUT_NEXT_DROP] = "error-drop",
 475     [DSLITE_IN2OUT_NEXT_IP4_LOOKUP] = "ip4-lookup",
 476     [DSLITE_IN2OUT_NEXT_IP6_ICMP] = "ip6-icmp-input",
 477     [DSLITE_IN2OUT_NEXT_SLOWPATH] = "dslite-in2out-slowpath",
 478   },
 479 };
 480 /* *INDENT-ON* */
 481
 482 VLIB_NODE_FN (dslite_in2out_slowpath_node) (vlib_main_t * vm,
 483                                             vlib_node_runtime_t * node,
 484                                             vlib_frame_t * frame)
 485 {
 486   return dslite_in2out_node_fn_inline (vm, node, frame, 1);
 487 }
 488
 489 /* *INDENT-OFF* */
 490 VLIB_REGISTER_NODE (dslite_in2out_slowpath_node) = {
 491   .name = "dslite-in2out-slowpath",
 492   .vector_size = sizeof (u32),
 493   .format_trace = format_dslite_trace,
 494   .type = VLIB_NODE_TYPE_INTERNAL,
 495   .n_errors = ARRAY_LEN (dslite_in2out_error_strings),
 496   .error_strings = dslite_in2out_error_strings,
 497   .n_next_nodes = DSLITE_IN2OUT_N_NEXT,
 498   /* edit / add dispositions here */
 499   .next_nodes = {
 500     [DSLITE_IN2OUT_NEXT_DROP] = "error-drop",
 501     [DSLITE_IN2OUT_NEXT_IP4_LOOKUP] = "ip4-lookup",
 502     [DSLITE_IN2OUT_NEXT_IP6_ICMP] = "ip6-lookup",
 503     [DSLITE_IN2OUT_NEXT_SLOWPATH] = "dslite-in2out-slowpath",
 504   },
 505 };
 506 /* *INDENT-ON* */
 507
 508 /*
 509  * fd.io coding-style-patch-verification: ON
 510  *
 511  * Local Variables:
 512  * eval: (c-set-style "gnu")
 513  * End:
 514  */