aboutsummaryrefslogtreecommitdiffstats
path: root/src/plugins/nat/dslite_in2out.c
blob: 54568914ce06ecdfa5c34856edff7eeabb4a84d8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
/*
 * Copyright (c) 2017 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#include <nat/dslite.h>

vlib_node_registration_t dslite_in2out_node;
vlib_node_registration_t dslite_in2out_slowpath_node;

typedef enum
{
  DSLITE_IN2OUT_NEXT_IP4_LOOKUP,
  DSLITE_IN2OUT_NEXT_IP6_ICMP,
  DSLITE_IN2OUT_NEXT_DROP,
  DSLITE_IN2OUT_NEXT_SLOWPATH,
  DSLITE_IN2OUT_N_NEXT,
} dslite_in2out_next_t;

static char *dslite_in2out_error_strings[] = {
#define _(sym,string) string,
  foreach_dslite_error
#undef _
};

static u32
slow_path (dslite_main_t * dm, dslite_session_key_t * in2out_key,
	   dslite_session_t ** sp, u32 next, u8 * error, u32 thread_index)
{
  dslite_b4_t *b4;
  clib_bihash_kv_16_8_t b4_kv, b4_value;
  clib_bihash_kv_24_8_t in2out_kv;
  clib_bihash_kv_8_8_t out2in_kv;
  dlist_elt_t *head_elt, *oldest_elt, *elt;
  u32 oldest_index;
  dslite_session_t *s;
  snat_session_key_t out2in_key;
  u32 address_index;

  out2in_key.protocol = in2out_key->proto;
  out2in_key.fib_index = 0;

  b4_kv.key[0] = in2out_key->softwire_id.as_u64[0];
  b4_kv.key[1] = in2out_key->softwire_id.as_u64[1];

  if (clib_bihash_search_16_8
      (&dm->per_thread_data[thread_index].b4_hash, &b4_kv, &b4_value))
    {
      pool_get (dm->per_thread_data[thread_index].b4s, b4);
      memset (b4, 0, sizeof (*b4));
      b4->addr.as_u64[0] = in2out_key->softwire_id.as_u64[0];
      b4->addr.as_u64[1] = in2out_key->softwire_id.as_u64[1];

      pool_get (dm->per_thread_data[thread_index].list_pool, head_elt);
      b4->sessions_per_b4_list_head_index =
	head_elt - dm->per_thread_data[thread_index].list_pool;
      clib_dlist_init (dm->per_thread_data[thread_index].list_pool,
		       b4->sessions_per_b4_list_head_index);

      b4_kv.value = b4 - dm->per_thread_data[thread_index].b4s;
      clib_bihash_add_del_16_8 (&dm->per_thread_data[thread_index].b4_hash,
				&b4_kv, 1);
    }
  else
    {
      b4 =
	pool_elt_at_index (dm->per_thread_data[thread_index].b4s,
			   b4_value.value);
    }

  //TODO configurable quota
  if (b4->nsessions >= 1000)
    {
      oldest_index =
	clib_dlist_remove_head (dm->per_thread_data[thread_index].list_pool,
				b4->sessions_per_b4_list_head_index);
      ASSERT (oldest_index != ~0);
      clib_dlist_addtail (dm->per_thread_data[thread_index].list_pool,
			  b4->sessions_per_b4_list_head_index, oldest_index);
      oldest_elt =
	pool_elt_at_index (dm->per_thread_data[thread_index].list_pool,
			   oldest_index);
      s =
	pool_elt_at_index (dm->per_thread_data[thread_index].sessions,
			   oldest_elt->value);

      in2out_kv.key[0] = s->in2out.as_u64[0];
      in2out_kv.key[1] = s->in2out.as_u64[1];
      in2out_kv.key[2] = s->in2out.as_u64[2];
      clib_bihash_add_del_24_8 (&dm->per_thread_data[thread_index].in2out,
				&in2out_kv, 0);
      out2in_kv.key = s->out2in.as_u64;
      clib_bihash_add_del_8_8 (&dm->per_thread_data[thread_index].out2in,
			       &out2in_kv, 0);
      snat_free_outside_address_and_port (dm->addr_pool, thread_index,
					  &s->out2in,
					  s->outside_address_index);
      s->outside_address_index = ~0;

      if (snat_alloc_outside_address_and_port
	  (dm->addr_pool, 0, thread_index, &out2in_key,
	   &s->outside_address_index, 0, dm->port_per_thread, thread_index))
	ASSERT (0);
    }
  else
    {
      if (snat_alloc_outside_address_and_port
	  (dm->addr_pool, 0, thread_index, &out2in_key, &address_index, 0,
	   dm->port_per_thread, thread_index))
	{
	  *error = DSLITE_ERROR_OUT_OF_PORTS;
	  return DSLITE_IN2OUT_NEXT_DROP;
	}
      pool_get (dm->per_thread_data[thread_index].sessions, s);
      memset (s, 0, sizeof (*s));
      s->outside_address_index = address_index;
      b4->nsessions++;

      pool_get (dm->per_thread_data[thread_index].list_pool, elt);
      clib_dlist_init (dm->per_thread_data[thread_index].list_pool,
		       elt - dm->per_thread_data[thread_index].list_pool);
      elt->value = s - dm->per_thread_data[thread_index].sessions;
      s->per_b4_index = elt - dm->per_thread_data[thread_index].list_pool;
      s->per_b4_list_head_index = b4->sessions_per_b4_list_head_index;
      clib_dlist_addtail (dm->per_thread_data[thread_index].list_pool,
			  s->per_b4_list_head_index,
			  elt - dm->per_thread_data[thread_index].list_pool);
    }

  s->in2out = *in2out_key;
  s->out2in = out2in_key;
  *sp = s;
  in2out_kv.key[0] = s->in2out.as_u64[0];
  in2out_kv.key[1] = s->in2out.as_u64[1];
  in2out_kv.key[2] = s->in2out.as_u64[2];
  in2out_kv.value = s - dm->per_thread_data[thread_index].sessions;
  clib_bihash_add_del_24_8 (&dm->per_thread_data[thread_index].in2out,
			    &in2out_kv, 1);
  out2in_kv.key = s->out2in.as_u64;
  out2in_kv.value = s - dm->per_thread_data[thread_index].sessions;
  clib_bihash_add_del_8_8 (&dm->per_thread_data[thread_index].out2in,
			   &out2in_kv, 1);

  return next;
}

static inline u32
dslite_icmp_in2out (dslite_main_t * dm, ip6_header_t * ip6,
		    ip4_header_t * ip4, dslite_session_t ** sp, u32 next,
		    u8 * error, u32 thread_index)
{
  dslite_session_t *s = 0;
  icmp46_header_t *icmp = ip4_next_header (ip4);
  clib_bihash_kv_24_8_t kv, value;
  dslite_session_key_t key;
  u32 n = next;
  icmp_echo_header_t *echo;
  u32 new_addr, old_addr;
  u16 old_id, new_id;
  ip_csum_t sum;

  if (icmp_is_error_message (icmp))
    {
      n = DSLITE_IN2OUT_NEXT_DROP;
      *error = DSLITE_ERROR_BAD_ICMP_TYPE;
      goto done;
    }

  echo = (icmp_echo_header_t *) (icmp + 1);

  key.addr = ip4->src_address;
  key.port = echo->identifier;
  key.proto = SNAT_PROTOCOL_ICMP;
  key.softwire_id.as_u64[0] = ip6->src_address.as_u64[0];
  key.softwire_id.as_u64[1] = ip6->src_address.as_u64[1];
  key.pad = 0;
  kv.key[0] = key.as_u64[0];
  kv.key[1] = key.as_u64[1];
  kv.key[2] = key.as_u64[2];

  if (clib_bihash_search_24_8
      (&dm->per_thread_data[thread_index].in2out, &kv, &value))
    {
      n = slow_path (dm, &key, &s, next, error, thread_index);
      if (PREDICT_FALSE (next == DSLITE_IN2OUT_NEXT_DROP))
	goto done;
    }
  else
    {
      s =
	pool_elt_at_index (dm->per_thread_data[thread_index].sessions,
			   value.value);
    }

  old_addr = ip4->src_address.as_u32;
  ip4->src_address = s->out2in.addr;
  new_addr = ip4->src_address.as_u32;
  sum = ip4->checksum;
  sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, src_address);
  ip4->checksum = ip_csum_fold (sum);

  old_id = echo->identifier;
  echo->identifier = new_id = s->out2in.port;
  sum = icmp->checksum;
  sum = ip_csum_update (sum, old_id, new_id, icmp_echo_header_t, identifier);
  icmp->checksum = ip_csum_fold (sum);

done:
  *sp = s;
  return n;
}

static inline uword
dslite_in2out_node_fn_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
			      vlib_frame_t * frame, u8 is_slow_path)
{
  u32 n_left_from, *from, *to_next;
  dslite_in2out_next_t next_index;
  u32 node_index;
  vlib_node_runtime_t *error_node;
  u32 thread_index = vlib_get_thread_index ();
  f64 now = vlib_time_now (vm);
  dslite_main_t *dm = &dslite_main;

  node_index =
    is_slow_path ? dslite_in2out_slowpath_node.
    index : dslite_in2out_node.index;

  error_node = vlib_node_get_runtime (vm, node_index);

  from = vlib_frame_vector_args (frame);
  n_left_from = frame->n_vectors;
  next_index = node->cached_next_index;

  while (n_left_from > 0)
    {
      u32 n_left_to_next;

      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

      while (n_left_from > 0 && n_left_to_next > 0)
	{
	  u32 bi0;
	  vlib_buffer_t *b0;
	  u32 next0 = DSLITE_IN2OUT_NEXT_IP4_LOOKUP;
	  ip4_header_t *ip40;
	  ip6_header_t *ip60;
	  u8 error0 = DSLITE_ERROR_IN2OUT;
	  u32 proto0;
	  dslite_session_t *s0 = 0;
	  clib_bihash_kv_24_8_t kv0, value0;
	  dslite_session_key_t key0;
	  udp_header_t *udp0;
	  tcp_header_t *tcp0;
	  ip_csum_t sum0;
	  u32 new_addr0, old_addr0;
	  u16 old_port0, new_port0;

	  /* speculatively enqueue b0 to the current next frame */
	  bi0 = from[0];
	  to_next[0] = bi0;
	  from += 1;
	  to_next += 1;
	  n_left_from -= 1;
	  n_left_to_next -= 1;

	  b0 = vlib_get_buffer (vm, bi0);
	  ip60 = vlib_buffer_get_current (b0);

	  if (PREDICT_FALSE (ip60->protocol != IP_PROTOCOL_IP_IN_IP))
	    {
	      if (ip60->protocol == IP_PROTOCOL_ICMP6)
		{
		  next0 = DSLITE_IN2OUT_NEXT_IP6_ICMP;
		  goto trace0;
		}
	      error0 = DSLITE_ERROR_BAD_IP6_PROTOCOL;
	      next0 = DSLITE_IN2OUT_NEXT_DROP;
	      goto trace0;
	    }

	  ip40 = vlib_buffer_get_current (b0) + sizeof (ip6_header_t);
	  proto0 = ip_proto_to_snat_proto (ip40->protocol);

	  if (PREDICT_FALSE (proto0 == ~0))
	    {
	      error0 = DSLITE_ERROR_UNSUPPORTED_PROTOCOL;
	      next0 = DSLITE_IN2OUT_NEXT_DROP;
	      goto trace0;
	    }

	  udp0 = ip4_next_header (ip40);
	  tcp0 = (tcp_header_t *) udp0;

	  if (is_slow_path)
	    {
	      if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
		{
		  next0 =
		    dslite_icmp_in2out (dm, ip60, ip40, &s0, next0, &error0,
					thread_index);
		  if (PREDICT_FALSE (next0 == DSLITE_IN2OUT_NEXT_DROP))
		    goto trace0;

		  goto accounting0;
		}
	    }
	  else
	    {
	      if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
		{
		  next0 = DSLITE_IN2OUT_NEXT_SLOWPATH;
		  goto trace0;
		}
	    }

	  key0.addr = ip40->src_address;
	  key0.port = udp0->src_port;
	  key0.proto = proto0;
	  key0.softwire_id.as_u64[0] = ip60->src_address.as_u64[0];
	  key0.softwire_id.as_u64[1] = ip60->src_address.as_u64[1];
	  key0.pad = 0;
	  kv0.key[0] = key0.as_u64[0];
	  kv0.key[1] = key0.as_u64[1];
	  kv0.key[2] = key0.as_u64[2];

	  if (clib_bihash_search_24_8
	      (&dm->per_thread_data[thread_index].in2out, &kv0, &value0))
	    {
	      if (is_slow_path)
		{
		  next0 =
		    slow_path (dm, &key0, &s0, next0, &error0, thread_index);
		  if (PREDICT_FALSE (next0 == DSLITE_IN2OUT_NEXT_DROP))
		    goto trace0;
		}
	      else
		{
		  next0 = DSLITE_IN2OUT_NEXT_SLOWPATH;
		  goto trace0;
		}
	    }
	  else
	    {
	      s0 =
		pool_elt_at_index (dm->per_thread_data[thread_index].sessions,
				   value0.value);
	    }

	  old_addr0 = ip40->src_address.as_u32;
	  ip40->src_address = s0->out2in.addr;
	  new_addr0 = ip40->src_address.as_u32;
	  sum0 = ip40->checksum;
	  sum0 =
	    ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
			    src_address);
	  ip40->checksum = ip_csum_fold (sum0);
	  if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
	    {
	      old_port0 = tcp0->src_port;
	      tcp0->src_port = s0->out2in.port;
	      new_port0 = tcp0->src_port;

	      sum0 = tcp0->checksum;
	      sum0 =
		ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
				dst_address);
	      sum0 =
		ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
				length);
	      tcp0->checksum = ip_csum_fold (sum0);
	    }
	  else
	    {
	      old_port0 = udp0->src_port;
	      udp0->src_port = s0->out2in.port;
	      udp0->checksum = 0;
	    }

	accounting0:
	  /* Accounting */
	  s0->last_heard = now;
	  s0->total_pkts++;
	  s0->total_bytes += vlib_buffer_length_in_chain (vm, b0);
	  /* Per-B4 LRU list maintenance */
	  clib_dlist_remove (dm->per_thread_data[thread_index].list_pool,
			     s0->per_b4_index);
	  clib_dlist_addtail (dm->per_thread_data[thread_index].list_pool,
			      s0->per_b4_list_head_index, s0->per_b4_index);

	  ip40->tos =
	    (clib_net_to_host_u32
	     (ip60->ip_version_traffic_class_and_flow_label) & 0x0ff00000) >>
	    20;
	  vlib_buffer_advance (b0, sizeof (ip6_header_t));

	trace0:
	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
			     && (b0->flags & VLIB_BUFFER_IS_TRACED)))
	    {
	      dslite_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
	      t->next_index = next0;
	      t->session_index = ~0;
	      if (s0)
		t->session_index =
		  s0 - dm->per_thread_data[thread_index].sessions;
	    }

	  b0->error = error_node->errors[error0];

	  /* verify speculative enqueue, maybe switch current next frame */
	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
					   n_left_to_next, bi0, next0);
	}
      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }

  return frame->n_vectors;
}

static uword
dslite_in2out_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
		       vlib_frame_t * frame)
{
  return dslite_in2out_node_fn_inline (vm, node, frame, 0);
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (dslite_in2out_node) = {
  .function = dslite_in2out_node_fn,
  .name = "dslite-in2out",
  .vector_size = sizeof (u32),
  .format_trace = format_dslite_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,
  .n_errors = ARRAY_LEN (dslite_in2out_error_strings),
  .error_strings = dslite_in2out_error_strings,
  .n_next_nodes = DSLITE_IN2OUT_N_NEXT,
  /* edit / add dispositions here */
  .next_nodes = {
    [DSLITE_IN2OUT_NEXT_DROP] = "error-drop",
    [DSLITE_IN2OUT_NEXT_IP4_LOOKUP] = "ip4-lookup",
    [DSLITE_IN2OUT_NEXT_IP6_ICMP] = "ip6-icmp-input",
    [DSLITE_IN2OUT_NEXT_SLOWPATH] = "dslite-in2out-slowpath",
  },
};
/* *INDENT-ON* */

VLIB_NODE_FUNCTION_MULTIARCH (dslite_in2out_node, dslite_in2out_node_fn);

static uword
dslite_in2out_slowpath_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
				vlib_frame_t * frame)
{
  return dslite_in2out_node_fn_inline (vm, node, frame, 1);
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (dslite_in2out_slowpath_node) = {
  .function = dslite_in2out_slowpath_node_fn,
  .name = "dslite-in2out-slowpath",
  .vector_size = sizeof (u32),
  .format_trace = format_dslite_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,
  .n_errors = ARRAY_LEN (dslite_in2out_error_strings),
  .error_strings = dslite_in2out_error_strings,
  .n_next_nodes = DSLITE_IN2OUT_N_NEXT,
  /* edit / add dispositions here */
  .next_nodes = {
    [DSLITE_IN2OUT_NEXT_DROP] = "error-drop",
    [DSLITE_IN2OUT_NEXT_IP4_LOOKUP] = "ip4-lookup",
    [DSLITE_IN2OUT_NEXT_IP6_ICMP] = "ip6-lookup",
    [DSLITE_IN2OUT_NEXT_SLOWPATH] = "dslite-in2out-slowpath",
  },
};
/* *INDENT-ON* */

VLIB_NODE_FUNCTION_MULTIARCH (dslite_in2out_slowpath_node,
			      dslite_in2out_slowpath_node_fn);

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */