summaryrefslogtreecommitdiffstats
path: root/src/vnet/tcp/tcp_inlines.h
blob: a01213080084ef208b74e6693ca77c7e54dc2229 (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
/*
 * Copyright (c) 2020 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.
 */

#ifndef SRC_VNET_TCP_TCP_INLINES_H_
#define SRC_VNET_TCP_TCP_INLINES_H_

#include <vnet/tcp/tcp.h>

always_inline tcp_header_t *
tcp_buffer_hdr (vlib_buffer_t * b)
{
  ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
  return (tcp_header_t *) (b->data + b->current_data
			   + vnet_buffer (b)->tcp.hdr_offset);
}

always_inline tcp_connection_t *
tcp_connection_get (u32 conn_index, u32 thread_index)
{
  tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
  if (PREDICT_FALSE (pool_is_free_index (wrk->connections, conn_index)))
    return 0;
  return pool_elt_at_index (wrk->connections, conn_index);
}

always_inline tcp_connection_t *
tcp_connection_get_if_valid (u32 conn_index, u32 thread_index)
{
  tcp_worker_ctx_t *wrk;
  if (thread_index >= vec_len (tcp_main.wrk_ctx))
    return 0;
  wrk = tcp_get_worker (thread_index);
  if (pool_is_free_index (wrk->connections, conn_index))
    return 0;
  return pool_elt_at_index (wrk->connections, conn_index);
}

always_inline void
tcp_connection_set_state (tcp_connection_t * tc, tcp_state_t state)
{
  tc->state = state;
  TCP_EVT (TCP_EVT_STATE_CHANGE, tc);
}

always_inline tcp_connection_t *
tcp_listener_get (u32 tli)
{
  tcp_connection_t *tc = 0;
  if (!pool_is_free_index (tcp_main.listener_pool, tli))
    tc = pool_elt_at_index (tcp_main.listener_pool, tli);
  return tc;
}

always_inline tcp_connection_t *
tcp_half_open_connection_get (u32 conn_index)
{
  tcp_connection_t *tc = 0;
  clib_spinlock_lock_if_init (&tcp_main.half_open_lock);
  if (!pool_is_free_index (tcp_main.half_open_connections, conn_index))
    tc = pool_elt_at_index (tcp_main.half_open_connections, conn_index);
  clib_spinlock_unlock_if_init (&tcp_main.half_open_lock);
  return tc;
}

/**
 * Our estimate of the number of bytes that have left the network
 */
always_inline u32
tcp_bytes_out (const tcp_connection_t * tc)
{
  if (tcp_opts_sack_permitted (&tc->rcv_opts))
    return tc->sack_sb.sacked_bytes + tc->sack_sb.lost_bytes;
  else
    return clib_min (tc->rcv_dupacks * tc->snd_mss,
		     tc->snd_nxt - tc->snd_una);
}

/**
 * Our estimate of the number of bytes in flight (pipe size)
 */
always_inline u32
tcp_flight_size (const tcp_connection_t * tc)
{
  int flight_size;

  flight_size = (int) (tc->snd_nxt - tc->snd_una) - tcp_bytes_out (tc)
    + tc->snd_rxt_bytes - tc->rxt_delivered;

  ASSERT (flight_size >= 0);

  return flight_size;
}

/**
 * Initial cwnd as per RFC5681
 */
always_inline u32
tcp_initial_cwnd (const tcp_connection_t * tc)
{
  if (tcp_cfg.initial_cwnd_multiplier > 0)
    return tcp_cfg.initial_cwnd_multiplier * tc->snd_mss;

  if (tc->snd_mss > 2190)
    return 2 * tc->snd_mss;
  else if (tc->snd_mss > 1095)
    return 3 * tc->snd_mss;
  else
    return 4 * tc->snd_mss;
}

/*
 * Accumulate acked bytes for cwnd increase
 *
 * Once threshold bytes are accumulated, snd_mss bytes are added
 * to the cwnd.
 */
always_inline void
tcp_cwnd_accumulate (tcp_connection_t * tc, u32 thresh, u32 bytes)
{
  tc->cwnd_acc_bytes += bytes;
  if (tc->cwnd_acc_bytes >= thresh)
    {
      u32 inc = tc->cwnd_acc_bytes / thresh;
      tc->cwnd_acc_bytes -= inc * thresh;
      tc->cwnd += inc * tc->snd_mss;
      tc->cwnd = clib_min (tc->cwnd, tc->tx_fifo_size);
    }
}

always_inline u32
tcp_loss_wnd (const tcp_connection_t * tc)
{
  /* Whatever we have in flight + the packet we're about to send */
  return tcp_flight_size (tc) + tc->snd_mss;
}

always_inline u32
tcp_available_snd_wnd (const tcp_connection_t * tc)
{
  return clib_min (tc->cwnd, tc->snd_wnd);
}

always_inline u32
tcp_available_output_snd_space (const tcp_connection_t * tc)
{
  u32 available_wnd = tcp_available_snd_wnd (tc);
  int flight_size = (int) (tc->snd_nxt - tc->snd_una);

  if (available_wnd <= flight_size)
    return 0;

  return available_wnd - flight_size;
}

/**
 * Estimate of how many bytes we can still push into the network
 */
always_inline u32
tcp_available_cc_snd_space (const tcp_connection_t * tc)
{
  u32 available_wnd = tcp_available_snd_wnd (tc);
  u32 flight_size = tcp_flight_size (tc);

  if (available_wnd <= flight_size)
    return 0;

  return available_wnd - flight_size;
}

always_inline u8
tcp_is_lost_fin (tcp_connection_t * tc)
{
  if ((tc->flags & TCP_CONN_FINSNT) && (tc->snd_nxt - tc->snd_una == 1))
    return 1;
  return 0;
}

/**
 * Time used to generate timestamps, not the timestamp
 */
always_inline u32
tcp_time_tstamp (u32 thread_index)
{
  return tcp_main.wrk_ctx[thread_index].time_tstamp;
}

/**
 * Generate timestamp for tcp connection
 */
always_inline u32
tcp_tstamp (tcp_connection_t * tc)
{
  return (tcp_main.wrk_ctx[tc->c_thread_index].time_tstamp -
	  tc->timestamp_delta);
}

always_inline f64
tcp_time_now_us (u32 thread_index)
{
  return tcp_main.wrk_ctx[thread_index].time_us;
}

always_inline void
tcp_set_time_now (tcp_worker_ctx_t *wrk, f64 now)
{
  /* TCP internal cache of time reference. Could use @ref transport_time_now
   * but because @ref tcp_time_now_us is used per packet, caching might
   * slightly improve efficiency. */
  wrk->time_us = now;
  wrk->time_tstamp = (u64) (now * TCP_TSTP_HZ);
}

always_inline void
tcp_update_time_now (tcp_worker_ctx_t *wrk)
{
  f64 now = vlib_time_now (wrk->vm);

  /* Both pacer and tcp us time need to be updated */
  transport_update_pacer_time (wrk->vm->thread_index, now);
  tcp_set_time_now (wrk, now);
}

always_inline tcp_connection_t *
tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
			 u8 is_ip4, u8 is_nolookup)
{
  u32 fib_index = vnet_buffer (b)->ip.fib_index;
  int n_advance_bytes, n_data_bytes;
  transport_connection_t *tc;
  tcp_header_t *tcp;
  u8 result = 0;

  if (is_ip4)
    {
      ip4_header_t *ip4 = vlib_buffer_get_current (b);
      int ip_hdr_bytes = ip4_header_bytes (ip4);
      if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
	{
	  *error = TCP_ERROR_LENGTH;
	  return 0;
	}
      tcp = ip4_next_header (ip4);
      vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
      n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
      n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;

      /* Length check. Checksum computed by ipx_local no need to compute again */
      if (PREDICT_FALSE (n_data_bytes < 0))
	{
	  *error = TCP_ERROR_LENGTH;
	  return 0;
	}

      if (!is_nolookup)
	tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
					    &ip4->src_address, tcp->dst_port,
					    tcp->src_port,
					    TRANSPORT_PROTO_TCP, thread_index,
					    &result);
    }
  else
    {
      ip6_header_t *ip6 = vlib_buffer_get_current (b);
      if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
	{
	  *error = TCP_ERROR_LENGTH;
	  return 0;
	}
      tcp = ip6_next_header (ip6);
      vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
      n_advance_bytes = tcp_header_bytes (tcp);
      n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
	- n_advance_bytes;
      n_advance_bytes += sizeof (ip6[0]);

      if (PREDICT_FALSE (n_data_bytes < 0))
	{
	  *error = TCP_ERROR_LENGTH;
	  return 0;
	}

      if (!is_nolookup)
	{
	  if (PREDICT_FALSE
	      (ip6_address_is_link_local_unicast (&ip6->dst_address)))
	    {
	      ip6_main_t *im = &ip6_main;
	      fib_index = vec_elt (im->fib_index_by_sw_if_index,
				   vnet_buffer (b)->sw_if_index[VLIB_RX]);
	    }

	  tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
					      &ip6->src_address,
					      tcp->dst_port, tcp->src_port,
					      TRANSPORT_PROTO_TCP,
					      thread_index, &result);
	}
    }

  if (is_nolookup)
    tc =
      (transport_connection_t *) tcp_connection_get (vnet_buffer (b)->
						     tcp.connection_index,
						     thread_index);

  vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
  vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
  vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
  vnet_buffer (b)->tcp.data_len = n_data_bytes;
  vnet_buffer (b)->tcp.seq_end = vnet_buffer (b)->tcp.seq_number
    + n_data_bytes;

  *error = result ? TCP_ERROR_NONE + result : *error;

  return tcp_get_connection_from_transport (tc);
}

/**
 * Initialize connection by gleaning network and rcv params from buffer
 *
 * @param tc		connection to initialize
 * @param b		buffer whose current data is pointing at ip
 * @param is_ip4	flag set to 1 if using ip4
 */
always_inline void
tcp_init_w_buffer (tcp_connection_t * tc, vlib_buffer_t * b, u8 is_ip4)
{
  tcp_header_t *th = tcp_buffer_hdr (b);

  tc->c_lcl_port = th->dst_port;
  tc->c_rmt_port = th->src_port;
  tc->c_is_ip4 = is_ip4;

  if (is_ip4)
    {
      ip4_header_t *ip4 = vlib_buffer_get_current (b);
      tc->c_lcl_ip4.as_u32 = ip4->dst_address.as_u32;
      tc->c_rmt_ip4.as_u32 = ip4->src_address.as_u32;
    }
  else
    {
      ip6_header_t *ip6 = vlib_buffer_get_current (b);
      clib_memcpy_fast (&tc->c_lcl_ip6, &ip6->dst_address,
			sizeof (ip6_address_t));
      clib_memcpy_fast (&tc->c_rmt_ip6, &ip6->src_address,
			sizeof (ip6_address_t));
    }

  tc->irs = vnet_buffer (b)->tcp.seq_number;
  tc->rcv_nxt = vnet_buffer (b)->tcp.seq_number + 1;
  tc->rcv_las = tc->rcv_nxt;
  tc->sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
  tc->snd_wl1 = vnet_buffer (b)->tcp.seq_number;
  tc->snd_wl2 = vnet_buffer (b)->tcp.ack_number;

  /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
   * segments are used to initialize PAWS. */
  if (tcp_opts_tstamp (&tc->rcv_opts))
    {
      tc->tsval_recent = tc->rcv_opts.tsval;
      tc->tsval_recent_age = tcp_time_tstamp (tc->c_thread_index);
    }

  if (tcp_opts_wscale (&tc->rcv_opts))
    tc->snd_wscale = tc->rcv_opts.wscale;

  tc->snd_wnd = clib_net_to_host_u16 (th->window) << tc->snd_wscale;
}

always_inline void
tcp_update_rto (tcp_connection_t * tc)
{
  tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
  tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
}

always_inline u8
tcp_is_descheduled (tcp_connection_t * tc)
{
  return (transport_connection_is_descheduled (&tc->connection) ? 1 : 0);
}

/**
 * Push TCP header to buffer
 *
 * @param vm - vlib_main
 * @param b - buffer to write the header to
 * @param sp_net - source port net order
 * @param dp_net - destination port net order
 * @param seq - sequence number net order
 * @param ack - ack number net order
 * @param tcp_hdr_opts_len - header and options length in bytes
 * @param flags - header flags
 * @param wnd - window size
 *
 * @return - pointer to start of TCP header
 */
always_inline void *
vlib_buffer_push_tcp_net_order (vlib_buffer_t * b, u16 sp, u16 dp, u32 seq,
				u32 ack, u8 tcp_hdr_opts_len, u8 flags,
				u16 wnd)
{
  tcp_header_t *th;

  th = vlib_buffer_push_uninit (b, tcp_hdr_opts_len);

  th->src_port = sp;
  th->dst_port = dp;
  th->seq_number = seq;
  th->ack_number = ack;
  th->data_offset_and_reserved = (tcp_hdr_opts_len >> 2) << 4;
  th->flags = flags;
  th->window = wnd;
  th->checksum = 0;
  th->urgent_pointer = 0;
  vnet_buffer (b)->l4_hdr_offset = (u8 *) th - b->data;
  b->flags |= VNET_BUFFER_F_L4_HDR_OFFSET_VALID;
  return th;
}

/**
 * Push TCP header to buffer
 *
 * @param b - buffer to write the header to
 * @param sp_net - source port net order
 * @param dp_net - destination port net order
 * @param seq - sequence number host order
 * @param ack - ack number host order
 * @param tcp_hdr_opts_len - header and options length in bytes
 * @param flags - header flags
 * @param wnd - window size
 *
 * @return - pointer to start of TCP header
 */
always_inline void *
vlib_buffer_push_tcp (vlib_buffer_t * b, u16 sp_net, u16 dp_net, u32 seq,
		      u32 ack, u8 tcp_hdr_opts_len, u8 flags, u16 wnd)
{
  return vlib_buffer_push_tcp_net_order (b, sp_net, dp_net,
					 clib_host_to_net_u32 (seq),
					 clib_host_to_net_u32 (ack),
					 tcp_hdr_opts_len, flags,
					 clib_host_to_net_u16 (wnd));
}

#endif /* SRC_VNET_TCP_TCP_INLINES_H_ */

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