aboutsummaryrefslogtreecommitdiffstats
path: root/src/vnet/sctp/sctp.h
blob: bc974d948de4d4a8cbf139959fd5b5e03ca1acc4 (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
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
/*
 * Copyright (c) 2017 SUSE LLC.
 * 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 included_vnet_sctp_h
#define included_vnet_sctp_h

#include <vnet/vnet.h>
#include <vnet/ip/ip.h>
#include <vnet/sctp/sctp_timer.h>
#include <vnet/sctp/sctp_packet.h>
#include <vnet/session/transport.h>
#include <vnet/session/session.h>

/* SCTP timers */
#define foreach_sctp_timer              	\
  _(T1_INIT, "T1_INIT")           			\
  _(T1_COOKIE, "T1_COOKIE")        			\
  _(T2_SHUTDOWN, "T2_SHUTDOWN")         	\
  _(T3_RXTX, "T3_RXTX")   					\
  _(T4_HEARTBEAT, "T4_HB")					\
  _(T5_SHUTDOWN_GUARD, "T5_SHUTDOWN_GUARD")

typedef enum _sctp_timers
{
#define _(sym, str) SCTP_TIMER_##sym,
  foreach_sctp_timer
#undef _
  SCTP_N_TIMERS
} sctp_timers_e;

#define SCTP_TIMER_HANDLE_INVALID ((u32) ~0)

always_inline char *
sctp_timer_to_string (u8 timer_id)
{
  switch (timer_id)
    {
    case SCTP_TIMER_T1_INIT:
      return "SCTP_TIMER_T1_INIT";
    case SCTP_TIMER_T1_COOKIE:
      return "SCTP_TIMER_T1_COOKIE";
    case SCTP_TIMER_T2_SHUTDOWN:
      return "SCTP_TIMER_T2_SHUTDOWN";
    case SCTP_TIMER_T3_RXTX:
      return "SCTP_TIMER_T3_RXTX";
    case SCTP_TIMER_T4_HEARTBEAT:
      return "SCTP_TIMER_T4_HEARTBEAT";
    case SCTP_TIMER_T5_SHUTDOWN_GUARD:
      return "SCTP_TIMER_T5_SHUTDOWN_GUARD";
    }
  return NULL;
}

typedef enum _sctp_error
{
#define sctp_error(n,s) SCTP_ERROR_##n,
#include <vnet/sctp/sctp_error.def>
#undef sctp_error
  SCTP_N_ERROR,
} sctp_error_t;

#define NO_FLAG 0

#define IS_T_BIT_SET(var) ((var) & (1))
#define IS_E_BIT_SET(var) ((var) & (1))
#define IS_B_BIT_SET(var) ((var) & (1<<1))
#define IS_U_BIT_SET(var) ((var) & (1<<2))

#define MAX_SCTP_CONNECTIONS 32
#define MAIN_SCTP_SUB_CONN_IDX 0

#if (VLIB_BUFFER_TRACE_TRAJECTORY)
#define sctp_trajectory_add_start(b, start)			\
{								\
    (*vlib_buffer_trace_trajectory_cb) (b, start);		\
}
#else
#define sctp_trajectory_add_start(b, start)
#endif

typedef struct _sctp_sub_connection
{
  transport_connection_t connection;	      /**< Common transport data. First! */
  void *parent;								/**< Link to the parent-super connection */

  u32 error_count; /**< The current error count for this destination. */
  u32 error_threshold; /**< Current error threshold for this destination,
				i.e. what value marks the destination down if error count reaches this value. */
  u32 cwnd; /**< The current congestion window. */
  u32 ssthresh;	/**< The current ssthresh value. */

  u32 rtt_ts;	/**< USED to hold the timestamp of when the packet has been sent */

  u32 RTO; /**< The current retransmission timeout value. */
  u32 SRTT; /**< The current smoothed round-trip time. */
  f32 RTTVAR; /**< The current RTT variation. */

  u32 partially_acked_bytes; /**< The tracking method for increase of cwnd when in
  	  	  	  	  congestion avoidance mode (see Section 7.2.2).*/

  u8 state; /**< The current state of this destination, i.e., DOWN, UP, ALLOW-HB, NO-HEARTBEAT, etc. */

  u16 PMTU; /**< The current known path MTU. */

  u32 timers[SCTP_N_TIMERS]; /**< A timer used by each destination. */

  u8 RTO_pending; /**< A flag used to track if one of the DATA chunks sent to
  	  	  	  	  this address is currently being used to compute an RTT.
  	  	  	  	  If this flag is 0, the next DATA chunk sent to this destination
  	  	  	  	  should be used to compute an RTT and this flag should be set.
  	  	  	  	  Every time the RTT calculation completes (i.e., the DATA chunk is SACK'd),
  	  	  	  	  clear this flag. */

  u32 last_time; /**< The time to which this destination was last sent a packet to.
  	  	  	  	  This can be used to determine if a HEARTBEAT is needed. */

  u8 unacknowledged_hb;	/**< Used to track how many unacknowledged heartbeats we had;
  	  	  	  	  If more than Max.Retransmit then connetion is considered unreachable. */

  u8 is_retransmitting;	/**< A flag (0 = no, 1 = yes) indicating whether the connection is retransmitting a previous packet */

} sctp_sub_connection_t;

typedef struct
{
  u32 a_rwnd; /**< Maximum segment size advertised */

} sctp_options_t;

/* Useful macros to deal with the out_of_order_map (array of bit) */
#define SET_BIT(A,k)     ( A[(k/32)] |= (1 << (k%32)) )
#define CLEAR_BIT(A,k)   ( A[(k/32)] &= ~(1 << (k%32)) )
#define TEST_BIT(A,k)    ( A[(k/32)] & (1 << (k%32)) )

always_inline void
_bytes_swap (void *pv, size_t n)
{
  char *p = pv;
  size_t lo, hi;
  for (lo = 0, hi = n - 1; hi > lo; lo++, hi--)
    {
      char tmp = p[lo];
      p[lo] = p[hi];
      p[hi] = tmp;
    }
}

#define ENDIANESS_SWAP(x) _bytes_swap(&x, sizeof(x));

#define MAX_INFLIGHT_PACKETS	128
#define MAX_ENQUEABLE_SACKS 2

/* This parameter indicates to the receiver how much increment in
 * milliseconds the sender wishes the receiver to add to its default
 * cookie life-span.
 */
#define SUGGESTED_COOKIE_LIFE_SPAN_INCREMENT 1000

typedef struct _sctp_connection
{
  sctp_sub_connection_t sub_conn[MAX_SCTP_CONNECTIONS];	/**< Common transport data. First! */

  u8 state;			/**< SCTP state as per sctp_state_t */
  u16 flags;		/**< Chunk flag (see sctp_chunks_common_hdr_t) */

  u32 local_tag;	/**< INIT_TAG generated locally */
  u32 remote_tag;	/**< INIT_TAG generated by the remote peer */

  u32 local_initial_tsn; /**< Initial TSN generated locally */
  u32 remote_initial_tsn; /**< Initial TSN generated by the remote-peer */

  u32 peer_cookie_life_span_increment;

  u32 overall_err_count; /**< The overall association error count. */
  u32 overall_err_treshold; /**< The threshold for this association that if the Overall Error Count
  	  	  	  	  reaches will cause this association to be torn down. */

  u32 peer_rwnd; /**< Current calculated value of the peer's rwnd. */

  u32 next_tsn;	/**< The next TSN number to be assigned to a new DATA chunk.
                 This is sent in the INIT or INIT ACK chunk to the peer
                 and incremented each time a DATA chunk is assigned a
                 TSN (normally just prior to transmit or during
                 fragmentation). */

  u32 next_tsn_expected; /**< The next TSN number expected to be received. */

  u32 last_rcvd_tsn; /**< This is the last TSN received in sequence. This value
     	 	 	 is set initially by taking the peer's initial TSN,
                 received in the INIT or INIT ACK chunk, and
                 subtracting one from it. */

  u32 out_of_order_map[MAX_INFLIGHT_PACKETS]; /**< An array of bits or bytes indicating which out-of-order
				TSNs have been received (relative to the Last Rcvd TSN).
				If no gaps exist, i.e., no out-of-order packets have been received,
				this array will be set to all zero. */

  u8 ack_state;	/**< This flag indicates if the next received packet is set to be responded to with a SACK.
  	  	  	  	This is initialized to 0. When a packet is received it is incremented.
  	  	  	  	If this value reaches 2 or more, a SACK is sent and the value is reset to 0.
  	  	  	  	Note: This is used only when no DATA chunks are received out-of-order.
  	  	  	  	When DATA chunks are out-of-order, SACKs are not delayed (see Section 6). */

  u32 a_rwnd; /** This value represents the dedicated buffer space, in number of bytes,
				the sender of the INIT has reserved in association with this window.
				During the life of the association, this buffer space SHOULD NOT be lessened
				(i.e., dedicated buffers taken away from this association);
				however, an endpoint MAY change the value of a_rwnd it sends in SACK chunks. */

  u32 smallest_PMTU; /** The smallest PMTU discovered for all of the peer's transport addresses. */

  u32 rcv_a_rwnd;		/**< LOCAL max seg size that includes options. To be updated by congestion algos, etc. */
  u32 snd_a_rwnd;		/**< REMOTE max seg size that includes options. To be updated if peer pushes back on window, etc.*/

  u8 overall_sending_status; /**< 0 indicates first fragment of a user message
  	  	  	  	  	  	  	  	  1 indicates normal stream
  	  	  	  	  	  	  	  	  2 indicates last fragment of a user message */

  sctp_options_t rcv_opts;
  sctp_options_t snd_opts;

  u32 snd_hdr_length;	/**< BASE HEADER LENGTH for the DATA chunk when sending */
  u8 next_avail_sub_conn; /**< Represent the index of the next free slot in sub_conn */

} sctp_connection_t;

typedef void (sctp_timer_expiration_handler) (u32 conn_index, u32 timer_id);

sctp_connection_t *sctp_connection_new (u8 thread_index);
void sctp_sub_connection_add_ip4 (u8 thread_index,
				  sctp_ipv4_addr_param_t * ipv4_addr);
void sctp_sub_connection_add_ip6 (u8 thread_index,
				  sctp_ipv6_addr_param_t * ipv6_addr);
void sctp_connection_close (sctp_connection_t * sctp_conn);
void sctp_connection_cleanup (sctp_connection_t * sctp_conn);
void sctp_connection_del (sctp_connection_t * sctp_conn);

u32 sctp_push_header (transport_connection_t * tconn, vlib_buffer_t * b);
void sctp_send_init (sctp_connection_t * sctp_conn);
void sctp_send_shutdown (sctp_connection_t * sctp_conn);
void sctp_send_shutdown_ack (sctp_connection_t * sctp_conn,
			     vlib_buffer_t * b);
void sctp_send_shutdown_complete (sctp_connection_t * sctp_conn);
void sctp_send_heartbeat (sctp_connection_t * sctp_conn);
void sctp_flush_frame_to_output (vlib_main_t * vm, u8 thread_index,
				 u8 is_ip4);
void sctp_flush_frames_to_output (u8 thread_index);
void sctp_punt_unknown (vlib_main_t * vm, u8 is_ip4, u8 is_add);

format_function_t format_sctp_state;

u8 *format_sctp_connection_id (u8 * s, va_list * args);
u8 *format_sctp_connection (u8 * s, va_list * args);
u8 *format_sctp_scoreboard (u8 * s, va_list * args);
u8 *format_sctp_header (u8 * s, va_list * args);
u8 *format_sctp_tx_trace (u8 * s, va_list * args);

clib_error_t *sctp_init (vlib_main_t * vm);
void sctp_connection_timers_init (sctp_connection_t * tc);
void sctp_connection_timers_reset (sctp_connection_t * tc);
void sctp_init_snd_vars (sctp_connection_t * tc);
void sctp_init_mss (sctp_connection_t * tc);

void sctp_prepare_initack_chunk (sctp_connection_t * ts, vlib_buffer_t * b,
				 ip4_address_t * ip4_addr,
				 ip6_address_t * ip6_addr);
void sctp_prepare_cookie_echo_chunk (sctp_connection_t * tc,
				     vlib_buffer_t * b,
				     sctp_state_cookie_param_t * sc);
void sctp_prepare_cookie_ack_chunk (sctp_connection_t * tc,
				    vlib_buffer_t * b);
void sctp_prepare_sack_chunk (sctp_connection_t * tc, vlib_buffer_t * b);
void sctp_prepare_heartbeat_ack_chunk (sctp_connection_t * sctp_conn,
				       vlib_buffer_t * b);

u16 sctp_check_outstanding_data_chunks (sctp_connection_t * tc);

#define IP_PROTOCOL_SCTP	132

/** SSCTP FSM state definitions as per RFC4960. */
#define foreach_sctp_fsm_state                \
  _(CLOSED, "CLOSED")                         \
  _(COOKIE_WAIT, "COOKIE_WAIT")               \
  _(COOKIE_ECHOED, "COOKIE_ECHOED")           \
  _(ESTABLISHED, "ESTABLISHED")               \
  _(SHUTDOWN_PENDING, "SHUTDOWN_PENDING")     \
  _(SHUTDOWN_SENT, "SHUTDOWN_SENT")           \
  _(SHUTDOWN_RECEIVED, "SHUTDOWN_RECEIVED")   \
  _(SHUTDOWN_ACK_SENT, "SHUTDOWN_ACK_SENT")

typedef enum _sctp_state
{
#define _(sym, str) SCTP_STATE_##sym,
  foreach_sctp_fsm_state
#undef _
  SCTP_N_STATES
} sctp_state_t;

always_inline char *
sctp_state_to_string (u8 state)
{
  switch (state)
    {
    case SCTP_STATE_CLOSED:
      return "SCTP_STATE_CLOSED";
    case SCTP_STATE_COOKIE_WAIT:
      return "SCTP_STATE_COOKIE_WAIT";
    case SCTP_STATE_COOKIE_ECHOED:
      return "SCTP_STATE_COOKIE_ECHOED";
    case SCTP_STATE_ESTABLISHED:
      return "SCTP_STATE_ESTABLISHED";
    case SCTP_STATE_SHUTDOWN_PENDING:
      return "SCTP_STATE_SHUTDOWN_PENDING";
    case SCTP_STATE_SHUTDOWN_SENT:
      return "SCTP_STATE_SHUTDOWN_SENT";
    case SCTP_STATE_SHUTDOWN_RECEIVED:
      return "SCTP_STATE_SHUTDOWN_RECEIVED";
    case SCTP_STATE_SHUTDOWN_ACK_SENT:
      return "SCTP_STATE_SHUTDOWN_ACK_SENT";
    }
  return NULL;
}

always_inline char *
sctp_chunk_to_string (u8 type)
{
  switch (type)
    {
    case DATA:
      return "DATA";
    case INIT:
      return "INIT";
    case INIT_ACK:
      return "INIT_ACK";
    case SACK:
      return "SACK";
    case HEARTBEAT:
      return "HEARTBEAT";
    case HEARTBEAT_ACK:
      return "HEARTBEAT_ACK";
    case ABORT:
      return "ABORT";
    case SHUTDOWN:
      return "SHUTDOWN";
    case SHUTDOWN_ACK:
      return "SHUTDOWN_ACK";
    case OPERATION_ERROR:
      return "OPERATION_ERROR";
    case COOKIE_ECHO:
      return "COOKIE_ECHO";
    case COOKIE_ACK:
      return "COOKIE_ACK";
    case ECNE:
      return "ECNE";
    case CWR:
      return "CWR";
    case SHUTDOWN_COMPLETE:
      return "SHUTDOWN_COMPLETE";
    }
  return NULL;
}

always_inline char *
sctp_optparam_type_to_string (u8 type)
{
  switch (type)
    {
    case SCTP_IPV4_ADDRESS_TYPE:
      return "SCTP_IPV4_ADDRESS_TYPE";
    case SCTP_IPV6_ADDRESS_TYPE:
      return "SCTP_IPV6_ADDRESS_TYPE";
    case SCTP_STATE_COOKIE_TYPE:
      return "SCTP_STATE_COOKIE_TYPE";
    case SCTP_UNRECOGNIZED_TYPE:
      return "SCTP_UNRECOGNIZED_TYPE";
    case SCTP_COOKIE_PRESERVATIVE_TYPE:
      return "SCTP_COOKIE_PRESERVATIVE_TYPE";
    case SCTP_HOSTNAME_ADDRESS_TYPE:
      return "SCTP_HOSTNAME_ADDRESS_TYPE";
    case SCTP_SUPPORTED_ADDRESS_TYPES:
      return "SCTP_SUPPORTED_ADDRESS_TYPES";
    }
  return NULL;
}

#define SCTP_TICK 0.001			/**< SCTP tick period (s) */
#define SHZ (u32) (1/SCTP_TICK)		/**< SCTP tick frequency */
#define SCTP_TSTAMP_RESOLUTION SCTP_TICK	/**< Time stamp resolution */

/* As per RFC4960, page 83 */
#define SCTP_RTO_INIT 3 * SHZ	/* 3 seconds */
#define SCTP_RTO_MIN 1 * SHZ	/* 1 second */
#define SCTP_RTO_MAX 60 * SHZ	/* 60 seconds */
#define SCTP_RTO_BURST	4
#define SCTP_RTO_ALPHA 1/8
#define SCTP_RTO_BETA 1/4
#define SCTP_VALID_COOKIE_LIFE 60 * SHZ	/* 60 seconds */
#define SCTP_ASSOCIATION_MAX_RETRANS 10

#define SCTP_TO_TIMER_TICK       SCTP_TICK*10	/* Period for converting from SCTP_TICK */

typedef struct _sctp_lookup_dispatch
{
  u8 next, error;
} sctp_lookup_dispatch_t;

typedef struct _sctp_main
{
  /* Per-worker thread SCTP connection pools */
  sctp_connection_t **connections;

  /* Pool of listeners. */
  sctp_connection_t *listener_pool;

	  /** Dispatch table by state and flags */
  sctp_lookup_dispatch_t dispatch_table[SCTP_N_STATES][64];

  u8 log2_tstamp_clocks_per_tick;
  f64 tstamp_ticks_per_clock;
  u32 *time_now;

	  /** per-worker tx buffer free lists */
  u32 **tx_buffers;
	  /** per-worker tx frames to SCTP 4/6 output nodes */
  vlib_frame_t **tx_frames[2];
	  /** per-worker tx frames to ip 4/6 lookup nodes */
  vlib_frame_t **ip_lookup_tx_frames[2];

  /* Per worker-thread timer wheel for connections timers */
  tw_timer_wheel_16t_2w_512sl_t *timer_wheels;

  /* Pool of half-open connections on which we've sent a SYN */
  sctp_connection_t *half_open_connections;
  clib_spinlock_t half_open_lock;

  /* TODO: Congestion control algorithms registered */
  /* sctp_cc_algorithm_t *cc_algos; */

  /* Flag that indicates if stack is on or off */
  u8 is_enabled;

	  /** Number of preallocated connections */
  u32 preallocated_connections;

	  /** Transport table (preallocation) size parameters */
  u32 local_endpoints_table_memory;
  u32 local_endpoints_table_buckets;

	  /** Vectors of src addresses. Optional unless one needs > 63K active-opens */
  ip4_address_t *ip4_src_addresses;
  u32 last_v4_address_rotor;
  u32 last_v6_address_rotor;
  ip6_address_t *ip6_src_addresses;

	  /** vlib buffer size */
  u32 bytes_per_buffer;

  u8 punt_unknown4;
  u8 punt_unknown6;

} sctp_main_t;

extern sctp_main_t sctp_main;
extern vlib_node_registration_t sctp4_input_node;
extern vlib_node_registration_t sctp6_input_node;
extern vlib_node_registration_t sctp4_output_node;
extern vlib_node_registration_t sctp6_output_node;

always_inline sctp_main_t *
vnet_get_sctp_main ()
{
  return &sctp_main;
}

always_inline sctp_header_t *
sctp_buffer_hdr (vlib_buffer_t * b)
{
  ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
  return (sctp_header_t *) (b->data + b->current_data
			    + vnet_buffer (b)->sctp.hdr_offset);
}

clib_error_t *vnet_sctp_enable_disable (vlib_main_t * vm, u8 is_en);

always_inline sctp_connection_t *
sctp_half_open_connection_get (u32 conn_index)
{
  sctp_connection_t *tc = 0;
  clib_spinlock_lock_if_init (&sctp_main.half_open_lock);
  if (!pool_is_free_index (sctp_main.half_open_connections, conn_index))
    tc = pool_elt_at_index (sctp_main.half_open_connections, conn_index);
  tc->sub_conn[MAIN_SCTP_SUB_CONN_IDX].parent = tc;
  clib_spinlock_unlock_if_init (&sctp_main.half_open_lock);
  return tc;
}

/**
 * Cleanup half-open connection
 *
 */
always_inline void
sctp_half_open_connection_del (sctp_connection_t * tc)
{
  sctp_main_t *tm = vnet_get_sctp_main ();
  clib_spinlock_lock_if_init (&tm->half_open_lock);
  pool_put_index (tm->half_open_connections,
		  tc->sub_conn[MAIN_SCTP_SUB_CONN_IDX].c_c_index);
  if (CLIB_DEBUG)
    memset (tc, 0xFA, sizeof (*tc));
  clib_spinlock_unlock_if_init (&tm->half_open_lock);
}

always_inline u32
sctp_set_time_now (u32 thread_index)
{
  sctp_main.time_now[thread_index] = clib_cpu_time_now ()
    * sctp_main.tstamp_ticks_per_clock;
  return sctp_main.time_now[thread_index];
}

always_inline void
sctp_timer_set (sctp_connection_t * tc, u8 conn_idx, u8 timer_id,
		u32 interval)
{
  ASSERT (tc->sub_conn[conn_idx].connection.thread_index ==
	  vlib_get_thread_index ());
  ASSERT (tc->sub_conn[conn_idx].timers[timer_id] ==
	  SCTP_TIMER_HANDLE_INVALID);

  sctp_sub_connection_t *sub = &tc->sub_conn[conn_idx];
  sub->timers[timer_id] =
    tw_timer_start_16t_2w_512sl (&sctp_main.timer_wheels[sub->c_thread_index],
				 sub->c_c_index, timer_id, interval);
}

always_inline void
sctp_timer_reset (sctp_connection_t * tc, u8 conn_idx, u8 timer_id)
{
  ASSERT (tc->sub_conn[conn_idx].c_thread_index == vlib_get_thread_index ());
  if (tc->sub_conn[conn_idx].timers[timer_id] == SCTP_TIMER_HANDLE_INVALID)
    return;

  sctp_sub_connection_t *sub = &tc->sub_conn[conn_idx];

  tw_timer_stop_16t_2w_512sl (&sctp_main.timer_wheels[sub->c_thread_index],
			      sub->timers[timer_id]);
  sub->timers[timer_id] = SCTP_TIMER_HANDLE_INVALID;
}

/**
 * Try to cleanup half-open connection
 *
 * If called from a thread that doesn't own tc, the call won't have any
 * effect.
 *
 * @param tc - connection to be cleaned up
 * @return non-zero if cleanup failed.
 */
always_inline int
sctp_half_open_connection_cleanup (sctp_connection_t * tc)
{
  /* Make sure this is the owning thread */
  if (tc->sub_conn[MAIN_SCTP_SUB_CONN_IDX].c_thread_index !=
      vlib_get_thread_index ())
    return 1;
  sctp_timer_reset (tc, MAIN_SCTP_SUB_CONN_IDX, SCTP_TIMER_T1_INIT);
  sctp_half_open_connection_del (tc);
  return 0;
}

always_inline u32
sctp_header_bytes ()
{
  return sizeof (sctp_header_t);
}

always_inline sctp_connection_t *
sctp_get_connection_from_transport (transport_connection_t * tconn)
{
  ASSERT (tconn != NULL);

  sctp_sub_connection_t *sub = (sctp_sub_connection_t *) tconn;
#if SCTP_ADV_DEBUG
  if (sub == NULL)
    SCTP_ADV_DBG ("sub == NULL");
  if (sub->parent == NULL)
    SCTP_ADV_DBG ("sub->parent == NULL");
#endif
  return (sctp_connection_t *) sub->parent;
}

always_inline u32
sctp_time_now (void)
{
  return sctp_main.time_now[vlib_get_thread_index ()];
}

#define ABS(x) ((x) > 0) ? (x) : -(x);

always_inline void
sctp_calculate_rto (sctp_connection_t * sctp_conn, u8 conn_idx)
{
  /* See RFC4960, 6.3.1.  RTO Calculation */
  u32 RTO = 0;
  f32 RTTVAR = 0;
  u32 now = sctp_time_now ();
  u32 prev_ts = sctp_conn->sub_conn[conn_idx].rtt_ts;
  u32 R = prev_ts - now;

  if (sctp_conn->sub_conn[conn_idx].RTO == 0)	// C1: Let's initialize our RTO
    {
      sctp_conn->sub_conn[conn_idx].RTO = SCTP_RTO_MIN;
      return;
    }

  if (sctp_conn->sub_conn[conn_idx].RTO == SCTP_RTO_MIN && sctp_conn->sub_conn[conn_idx].SRTT == 0)	// C2: First RTT calculation
    {
      sctp_conn->sub_conn[conn_idx].SRTT = R;
      RTTVAR = R / 2;

      if (RTTVAR == 0)
	RTTVAR = 100e-3;	/* 100 ms */

      sctp_conn->sub_conn[conn_idx].RTTVAR = RTTVAR;
    }
  else				// C3: RTT already exists; let's recalculate
    {
      RTTVAR = (1 - SCTP_RTO_BETA) * sctp_conn->sub_conn[conn_idx].RTTVAR +
	SCTP_RTO_BETA * ABS (sctp_conn->sub_conn[conn_idx].SRTT - R);

      if (RTTVAR == 0)
	RTTVAR = 100e-3;	/* 100 ms */

      sctp_conn->sub_conn[conn_idx].RTTVAR = RTTVAR;

      sctp_conn->sub_conn[conn_idx].SRTT =
	(1 - SCTP_RTO_ALPHA) * sctp_conn->sub_conn[conn_idx].SRTT +
	SCTP_RTO_ALPHA * R;
    }

  RTO =
    sctp_conn->sub_conn[conn_idx].SRTT +
    4 * sctp_conn->sub_conn[conn_idx].RTTVAR;
  if (RTO < SCTP_RTO_MIN)	// C6
    RTO = SCTP_RTO_MIN;

  if (RTO > SCTP_RTO_MAX)	// C7
    RTO = SCTP_RTO_MAX;

  sctp_conn->sub_conn[conn_idx].RTO = RTO;
}

always_inline void
sctp_timer_update (sctp_connection_t * tc, u8 conn_idx, u8 timer_id,
		   u32 interval)
{
  ASSERT (tc->sub_conn[conn_idx].connection.thread_index ==
	  vlib_get_thread_index ());
  sctp_sub_connection_t *sub = &tc->sub_conn[conn_idx];

  if (tc->sub_conn[conn_idx].timers[timer_id] != SCTP_TIMER_HANDLE_INVALID)
    tw_timer_stop_16t_2w_512sl (&sctp_main.timer_wheels[sub->c_thread_index],
				sub->timers[timer_id]);

  tc->sub_conn[conn_idx].timers[timer_id] =
    tw_timer_start_16t_2w_512sl (&sctp_main.timer_wheels[sub->c_thread_index],
				 sub->c_c_index, timer_id, interval);
}

always_inline sctp_connection_t *
sctp_listener_get (u32 tli)
{
  return pool_elt_at_index (sctp_main.listener_pool, tli);
}

#endif

always_inline sctp_connection_t *
sctp_connection_get (u32 conn_index, u32 thread_index)
{
  if (PREDICT_FALSE
      (pool_is_free_index (sctp_main.connections[thread_index], conn_index)))
    return 0;
  return pool_elt_at_index (sctp_main.connections[thread_index], conn_index);
}

always_inline u8
sctp_pick_conn_idx_on_chunk (sctp_chunk_type chunk_type)
{
  u8 idx = MAIN_SCTP_SUB_CONN_IDX;

  switch (chunk_type)
    {
    case DATA:
    case INIT:
    case INIT_ACK:
    case SACK:
    case HEARTBEAT:
    case HEARTBEAT_ACK:
    case ABORT:
    case SHUTDOWN:
    case SHUTDOWN_ACK:
    case OPERATION_ERROR:
    case COOKIE_ECHO:
    case COOKIE_ACK:
    case ECNE:
    case CWR:
    case SHUTDOWN_COMPLETE:
      idx = MAIN_SCTP_SUB_CONN_IDX;
    }
  return idx;
}

always_inline u8
sctp_pick_conn_idx_on_state (sctp_state_t state)
{
  u8 idx = MAIN_SCTP_SUB_CONN_IDX;

  switch (state)
    {
    case SCTP_STATE_CLOSED:
    case SCTP_STATE_COOKIE_WAIT:
    case SCTP_STATE_COOKIE_ECHOED:
    case SCTP_STATE_ESTABLISHED:
    case SCTP_STATE_SHUTDOWN_PENDING:
    case SCTP_STATE_SHUTDOWN_SENT:
    case SCTP_STATE_SHUTDOWN_RECEIVED:
    case SCTP_STATE_SHUTDOWN_ACK_SENT:
      idx = MAIN_SCTP_SUB_CONN_IDX;
    default:
      idx = MAIN_SCTP_SUB_CONN_IDX;
    }
  return idx;
}

/**
 * Push SCTP 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 sctp_hdr_opts_len - header and options length in bytes
 *
 * @return - pointer to start of SCTP header
 */
always_inline void *
vlib_buffer_push_sctp_net_order (vlib_buffer_t * b, u16 sp, u16 dp,
				 u8 sctp_hdr_opts_len)
{
  sctp_full_hdr_t *full_hdr;

  full_hdr = vlib_buffer_push_uninit (b, sctp_hdr_opts_len);

  full_hdr->hdr.src_port = sp;
  full_hdr->hdr.dst_port = dp;
  full_hdr->hdr.checksum = 0;
  return full_hdr;
}

/**
 * Push SCTP 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 sctp_hdr_opts_len - header and options length in bytes
 *
 * @return - pointer to start of SCTP header
 */
always_inline void *
vlib_buffer_push_sctp (vlib_buffer_t * b, u16 sp_net, u16 dp_net,
		       u8 sctp_hdr_opts_len)
{
  return vlib_buffer_push_sctp_net_order (b, sp_net, dp_net,
					  sctp_hdr_opts_len);
}

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