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Vector Packet Processing
tcp.h
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1 /*
2  * Copyright (c) 2016 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 
16 #ifndef _vnet_tcp_h_
17 #define _vnet_tcp_h_
18 
19 #include <vnet/vnet.h>
20 #include <vnet/ip/ip.h>
21 #include <vnet/tcp/tcp_packet.h>
22 #include <vnet/tcp/tcp_timer.h>
23 #include <vnet/session/transport.h>
24 #include <vnet/session/session.h>
25 #include <vnet/tcp/tcp_debug.h>
26 
27 #define TCP_TICK 0.001 /**< TCP tick period (s) */
28 #define THZ (u32) (1/TCP_TICK) /**< TCP tick frequency */
29 #define TCP_TSTAMP_RESOLUTION TCP_TICK /**< Time stamp resolution */
30 #define TCP_PAWS_IDLE 24 * 24 * 60 * 60 * THZ /**< 24 days */
31 #define TCP_FIB_RECHECK_PERIOD 1 * THZ /**< Recheck every 1s */
32 #define TCP_MAX_OPTION_SPACE 40
33 
34 #define TCP_DUPACK_THRESHOLD 3
35 #define TCP_MAX_RX_FIFO_SIZE 4 << 20
36 #define TCP_MIN_RX_FIFO_SIZE 4 << 10
37 #define TCP_IW_N_SEGMENTS 10
38 #define TCP_ALWAYS_ACK 1 /**< On/off delayed acks */
39 #define TCP_USE_SACKS 1 /**< Disable only for testing */
40 
41 /** TCP FSM state definitions as per RFC793. */
42 #define foreach_tcp_fsm_state \
43  _(CLOSED, "CLOSED") \
44  _(LISTEN, "LISTEN") \
45  _(SYN_SENT, "SYN_SENT") \
46  _(SYN_RCVD, "SYN_RCVD") \
47  _(ESTABLISHED, "ESTABLISHED") \
48  _(CLOSE_WAIT, "CLOSE_WAIT") \
49  _(FIN_WAIT_1, "FIN_WAIT_1") \
50  _(LAST_ACK, "LAST_ACK") \
51  _(CLOSING, "CLOSING") \
52  _(FIN_WAIT_2, "FIN_WAIT_2") \
53  _(TIME_WAIT, "TIME_WAIT")
54 
55 typedef enum _tcp_state
56 {
57 #define _(sym, str) TCP_STATE_##sym,
59 #undef _
61 } tcp_state_t;
62 
67 
68 /** TCP timers */
69 #define foreach_tcp_timer \
70  _(RETRANSMIT, "RETRANSMIT") \
71  _(DELACK, "DELAYED ACK") \
72  _(PERSIST, "PERSIST") \
73  _(KEEP, "KEEP") \
74  _(WAITCLOSE, "WAIT CLOSE") \
75  _(RETRANSMIT_SYN, "RETRANSMIT SYN") \
76  _(ESTABLISH, "ESTABLISH")
77 
78 typedef enum _tcp_timers
79 {
80 #define _(sym, str) TCP_TIMER_##sym,
82 #undef _
84 } tcp_timers_e;
85 
86 typedef void (timer_expiration_handler) (u32 index);
87 
92 
93 #define TCP_TIMER_HANDLE_INVALID ((u32) ~0)
94 
95 /* Timer delays as multiples of 100ms */
96 #define TCP_TO_TIMER_TICK TCP_TICK*10 /* Period for converting from TCP
97  * ticks to timer units */
98 #define TCP_DELACK_TIME 1 /* 0.1s */
99 #define TCP_ESTABLISH_TIME 750 /* 75s */
100 #define TCP_SYN_RCVD_TIME 600 /* 60s */
101 #define TCP_2MSL_TIME 300 /* 30s */
102 #define TCP_CLOSEWAIT_TIME 20 /* 2s */
103 #define TCP_TIMEWAIT_TIME 100 /* 10s */
104 #define TCP_CLEANUP_TIME 10 /* 1s Time to wait before cleanup */
105 #define TCP_TIMER_PERSIST_MIN 2 /* 0.2s */
106 
107 #define TCP_RTO_MAX 60 * THZ /* Min max RTO (60s) as per RFC6298 */
108 #define TCP_RTO_MIN 0.2 * THZ /* Min RTO (200ms) - lower than standard */
109 #define TCP_RTT_MAX 30 * THZ /* 30s (probably too much) */
110 #define TCP_RTO_SYN_RETRIES 3 /* SYN retries without doubling RTO */
111 #define TCP_RTO_INIT 1 * THZ /* Initial retransmit timer */
112 
113 /** TCP connection flags */
114 #define foreach_tcp_connection_flag \
115  _(SNDACK, "Send ACK") \
116  _(FINSNT, "FIN sent") \
117  _(SENT_RCV_WND0, "Sent 0 rcv_wnd") \
118  _(RECOVERY, "Recovery") \
119  _(FAST_RECOVERY, "Fast Recovery") \
120  _(FR_1_SMSS, "Sent 1 SMSS") \
121  _(HALF_OPEN_DONE, "Half-open completed") \
122  _(FINPNDG, "FIN pending") \
123 
124 typedef enum _tcp_connection_flag_bits
125 {
126 #define _(sym, str) TCP_CONN_##sym##_BIT,
128 #undef _
131 
132 typedef enum _tcp_connection_flag
133 {
134 #define _(sym, str) TCP_CONN_##sym = 1 << TCP_CONN_##sym##_BIT,
136 #undef _
139 
140 /** TCP buffer flags */
141 #define foreach_tcp_buf_flag \
142  _ (ACK) /**< Sending ACK. */ \
143  _ (DUPACK) /**< Sending DUPACK. */ \
144 
145 enum
146 {
147 #define _(f) TCP_BUF_BIT_##f,
149 #undef _
151 };
152 
153 enum
154 {
155 #define _(f) TCP_BUF_FLAG_##f = 1 << TCP_BUF_BIT_##f,
157 #undef _
158 };
159 
160 #define TCP_SCOREBOARD_TRACE (0)
161 #define TCP_MAX_SACK_BLOCKS 15 /**< Max number of SACK blocks stored */
162 #define TCP_INVALID_SACK_HOLE_INDEX ((u32)~0)
164 typedef struct _scoreboard_trace_elt
165 {
166  u32 start;
167  u32 end;
168  u32 ack;
169  u32 snd_una_max;
170  u32 group;
172 
173 typedef struct _sack_scoreboard_hole
174 {
175  u32 next; /**< Index for next entry in linked list */
176  u32 prev; /**< Index for previous entry in linked list */
177  u32 start; /**< Start sequence number */
178  u32 end; /**< End sequence number */
179  u8 is_lost; /**< Mark hole as lost */
181 
182 typedef struct _sack_scoreboard
183 {
184  sack_scoreboard_hole_t *holes; /**< Pool of holes */
185  u32 head; /**< Index of first entry */
186  u32 tail; /**< Index of last entry */
187  u32 sacked_bytes; /**< Number of bytes sacked in sb */
188  u32 last_sacked_bytes; /**< Number of bytes last sacked */
189  u32 last_bytes_delivered; /**< Number of sack bytes delivered */
190  u32 snd_una_adv; /**< Bytes to add to snd_una */
191  u32 high_sacked; /**< Highest byte sacked (fack) */
192  u32 high_rxt; /**< Highest retransmitted sequence */
193  u32 rescue_rxt; /**< Rescue sequence number */
194  u32 lost_bytes; /**< Bytes lost as per RFC6675 */
195  u32 cur_rxt_hole; /**< Retransmitting from this hole */
196 
197 #if TCP_SCOREBOARD_TRACE
199 #endif
200 
202 
203 #if TCP_SCOREBOARD_TRACE
204 #define tcp_scoreboard_trace_add(_tc, _ack) \
205 { \
206  static u64 _group = 0; \
207  sack_scoreboard_t *_sb = &_tc->sack_sb; \
208  sack_block_t *_sack, *_sacks; \
209  scoreboard_trace_elt_t *_elt; \
210  int i; \
211  _group++; \
212  _sacks = _tc->rcv_opts.sacks; \
213  for (i = 0; i < vec_len (_sacks); i++) \
214  { \
215  _sack = &_sacks[i]; \
216  vec_add2 (_sb->trace, _elt, 1); \
217  _elt->start = _sack->start; \
218  _elt->end = _sack->end; \
219  _elt->ack = _elt->end == _ack ? _ack : 0; \
220  _elt->snd_una_max = _elt->end == _ack ? _tc->snd_una_max : 0; \
221  _elt->group = _group; \
222  } \
223 }
224 #else
225 #define tcp_scoreboard_trace_add(_tc, _ack)
226 #endif
227 
230  start, u8 have_sent_1_smss,
231  u8 * can_rescue,
232  u8 * snd_limited);
234  u32 index);
235 
237  sack_scoreboard_hole_t * hole);
239  sack_scoreboard_hole_t * hole);
244 u8 *format_tcp_scoreboard (u8 * s, va_list * args);
245 
246 typedef enum _tcp_cc_algorithm_type
247 {
250 
251 typedef struct _tcp_cc_algorithm tcp_cc_algorithm_t;
253 typedef enum _tcp_cc_ack_t
254 {
255  TCP_CC_ACK,
259 
260 typedef struct _tcp_connection
261 {
262  transport_connection_t connection; /**< Common transport data. First! */
263 
264  u8 state; /**< TCP state as per tcp_state_t */
265  u16 flags; /**< Connection flags (see tcp_conn_flags_e) */
266  u32 timers[TCP_N_TIMERS]; /**< Timer handles into timer wheel */
267 
268  /* TODO RFC4898 */
269 
270  /** Send sequence variables RFC793 */
271  u32 snd_una; /**< oldest unacknowledged sequence number */
272  u32 snd_una_max; /**< newest unacknowledged sequence number + 1*/
273  u32 snd_wnd; /**< send window */
274  u32 snd_wl1; /**< seq number used for last snd.wnd update */
275  u32 snd_wl2; /**< ack number used for last snd.wnd update */
276  u32 snd_nxt; /**< next seq number to be sent */
277  u16 snd_mss; /**< Effective send max seg (data) size */
278 
279  /** Receive sequence variables RFC793 */
280  u32 rcv_nxt; /**< next sequence number expected */
281  u32 rcv_wnd; /**< receive window we expect */
282 
283  u32 rcv_las; /**< rcv_nxt at last ack sent/rcv_wnd update */
284  u32 iss; /**< initial sent sequence */
285  u32 irs; /**< initial remote sequence */
286 
287  /* Options */
288  u8 snd_opts_len; /**< Tx options len */
289  u8 rcv_wscale; /**< Window scale to advertise to peer */
290  u8 snd_wscale; /**< Window scale to use when sending */
291  u32 tsval_recent; /**< Last timestamp received */
292  u32 tsval_recent_age; /**< When last updated tstamp_recent*/
293  tcp_options_t snd_opts; /**< Tx options for connection */
294  tcp_options_t rcv_opts; /**< Rx options for connection */
295 
296  sack_block_t *snd_sacks; /**< Vector of SACKs to send. XXX Fixed size? */
297  sack_scoreboard_t sack_sb; /**< SACK "scoreboard" that tracks holes */
298 
299  u16 rcv_dupacks; /**< Number of DUPACKs received */
300  u8 snt_dupacks; /**< Number of DUPACKs sent in a burst */
301 
302  /* Congestion control */
303  u32 cwnd; /**< Congestion window */
304  u32 cwnd_acc_bytes; /**< Bytes accumulated for cwnd increment */
305  u32 ssthresh; /**< Slow-start threshold */
306  u32 prev_ssthresh; /**< ssthresh before congestion */
307  u32 prev_cwnd; /**< ssthresh before congestion */
308  u32 bytes_acked; /**< Bytes acknowledged by current segment */
309  u32 snd_rxt_bytes; /**< Retransmitted bytes */
310  u32 snd_rxt_ts; /**< Timestamp when first packet is retransmitted */
311  u32 tsecr_last_ack; /**< Timestamp echoed to us in last healthy ACK */
312  u32 snd_congestion; /**< snd_una_max when congestion is detected */
313  tcp_cc_algorithm_t *cc_algo; /**< Congestion control algorithm */
314 
315  /* RTT and RTO */
316  u32 rto; /**< Retransmission timeout */
317  u32 rto_boff; /**< Index for RTO backoff */
318  u32 srtt; /**< Smoothed RTT */
319  u32 rttvar; /**< Smoothed mean RTT difference. Approximates variance */
320  u32 rtt_ts; /**< Timestamp for tracked ACK */
321  u32 rtt_seq; /**< Sequence number for tracked ACK */
322 
323  u16 mss; /**< Our max seg size that includes options */
324  u32 limited_transmit; /**< snd_nxt when limited transmit starts */
325  u32 last_fib_check; /**< Last time we checked fib route for peer */
326  u32 sw_if_index; /**< Interface for the connection */
328 
329 struct _tcp_cc_algorithm
330 {
331  void (*rcv_ack) (tcp_connection_t * tc);
332  void (*rcv_cong_ack) (tcp_connection_t * tc, tcp_cc_ack_t ack);
333  void (*congestion) (tcp_connection_t * tc);
334  void (*recovered) (tcp_connection_t * tc);
335  void (*init) (tcp_connection_t * tc);
336 };
337 
338 #define tcp_fastrecovery_on(tc) (tc)->flags |= TCP_CONN_FAST_RECOVERY
339 #define tcp_fastrecovery_off(tc) (tc)->flags &= ~TCP_CONN_FAST_RECOVERY
340 #define tcp_recovery_on(tc) (tc)->flags |= TCP_CONN_RECOVERY
341 #define tcp_recovery_off(tc) (tc)->flags &= ~TCP_CONN_RECOVERY
342 #define tcp_in_fastrecovery(tc) ((tc)->flags & TCP_CONN_FAST_RECOVERY)
343 #define tcp_in_recovery(tc) ((tc)->flags & (TCP_CONN_RECOVERY))
344 #define tcp_in_slowstart(tc) (tc->cwnd < tc->ssthresh)
345 #define tcp_fastrecovery_sent_1_smss(tc) ((tc)->flags & TCP_CONN_FR_1_SMSS)
346 #define tcp_fastrecovery_1_smss_on(tc) ((tc)->flags |= TCP_CONN_FR_1_SMSS)
347 #define tcp_fastrecovery_1_smss_off(tc) ((tc)->flags &= ~TCP_CONN_FR_1_SMSS)
349 #define tcp_in_cong_recovery(tc) ((tc)->flags & \
350  (TCP_CONN_FAST_RECOVERY | TCP_CONN_RECOVERY))
351 
352 always_inline void
354 {
355  tc->flags &= ~(TCP_CONN_FAST_RECOVERY | TCP_CONN_RECOVERY);
357 }
358 
359 typedef enum _tcp_error
360 {
361 #define tcp_error(n,s) TCP_ERROR_##n,
363 #undef tcp_error
364  TCP_N_ERROR,
366 
367 typedef struct _tcp_lookup_dispatch
368 {
369  u8 next, error;
371 
372 typedef struct tcp_worker_ctx_
373 {
374  CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
375  u32 time_now; /**< worker time */
376  tw_timer_wheel_16t_2w_512sl_t timer_wheel; /**< worker timer wheel */
377  u32 *tx_buffers; /**< tx buffer free list */
378  vlib_frame_t *tx_frames[2]; /**< tx frames for tcp 4/6
379  output nodes */
380  vlib_frame_t *ip_lookup_tx_frames[2]; /**< tx frames for ip 4/6
381  lookup nodes */
383 
384 typedef struct _tcp_main
385 {
386  /* Per-worker thread tcp connection pools */
387  tcp_connection_t **connections;
388 
389  /* Pool of listeners. */
390  tcp_connection_t *listener_pool;
391 
392  /** Dispatch table by state and flags */
393  tcp_lookup_dispatch_t dispatch_table[TCP_N_STATES][64];
394 
395  u8 log2_tstamp_clocks_per_tick;
396  f64 tstamp_ticks_per_clock;
397 
398  /** per-worker context */
399  tcp_worker_ctx_t *wrk_ctx;
400 
401  /* Pool of half-open connections on which we've sent a SYN */
402  tcp_connection_t *half_open_connections;
403  clib_spinlock_t half_open_lock;
404 
405  /* Congestion control algorithms registered */
406  tcp_cc_algorithm_t *cc_algos;
407 
408  /* Flag that indicates if stack is on or off */
409  u8 is_enabled;
410 
411  /** Number of preallocated connections */
412  u32 preallocated_connections;
413  u32 preallocated_half_open_connections;
414 
415  /** Vectors of src addresses. Optional unless one needs > 63K active-opens */
416  ip4_address_t *ip4_src_addresses;
417  u32 last_v4_address_rotor;
418  u32 last_v6_address_rotor;
419  ip6_address_t *ip6_src_addresses;
420 
421  /** vlib buffer size */
422  u32 bytes_per_buffer;
423 
424  u8 punt_unknown4;
425  u8 punt_unknown6;
426 
427  /** fault-injection */
428  f64 buffer_fail_fraction;
429 } tcp_main_t;
430 
431 extern tcp_main_t tcp_main;
436 
439 {
440  return &tcp_main;
441 }
442 
445 {
446  ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
447  return (tcp_header_t *) (b->data + b->current_data
448  + vnet_buffer (b)->tcp.hdr_offset);
449 }
450 
451 #if (VLIB_BUFFER_TRACE_TRAJECTORY)
452 #define tcp_trajectory_add_start(b, start) \
453 { \
454  (*vlib_buffer_trace_trajectory_cb) (b, start); \
455 }
456 #else
457 #define tcp_trajectory_add_start(b, start)
458 #endif
459 
461 
462 void tcp_punt_unknown (vlib_main_t * vm, u8 is_ip4, u8 is_add);
463 
465 tcp_connection_get (u32 conn_index, u32 thread_index)
466 {
467  if (PREDICT_FALSE
468  (pool_is_free_index (tcp_main.connections[thread_index], conn_index)))
469  return 0;
470  return pool_elt_at_index (tcp_main.connections[thread_index], conn_index);
471 }
472 
474 tcp_connection_get_if_valid (u32 conn_index, u32 thread_index)
475 {
476  if (tcp_main.connections[thread_index] == 0)
477  return 0;
478  if (pool_is_free_index (tcp_main.connections[thread_index], conn_index))
479  return 0;
480  return pool_elt_at_index (tcp_main.connections[thread_index], conn_index);
481 }
482 
485 {
486  return (tcp_connection_t *) tconn;
487 }
488 
493 tcp_connection_t *tcp_connection_new (u8 thread_index);
496  ip4_address_t * start,
497  ip4_address_t * end, u32 table_id);
499  ip6_address_t * start,
500  ip6_address_t * end, u32 table_id);
501 void tcp_api_reference (void);
502 u8 *format_tcp_connection (u8 * s, va_list * args);
503 
505 tcp_listener_get (u32 tli)
506 {
507  return pool_elt_at_index (tcp_main.listener_pool, tli);
508 }
509 
512 {
513  tcp_connection_t *tc = 0;
514  clib_spinlock_lock_if_init (&tcp_main.half_open_lock);
515  if (!pool_is_free_index (tcp_main.half_open_connections, conn_index))
516  tc = pool_elt_at_index (tcp_main.half_open_connections, conn_index);
517  clib_spinlock_unlock_if_init (&tcp_main.half_open_lock);
518  return tc;
519 }
520 
525  u8 is_ip4);
526 void tcp_send_reset (tcp_connection_t * tc);
527 void tcp_send_syn (tcp_connection_t * tc);
528 void tcp_send_fin (tcp_connection_t * tc);
529 void tcp_init_mss (tcp_connection_t * tc);
531 void tcp_update_rto (tcp_connection_t * tc);
532 void tcp_flush_frame_to_output (vlib_main_t * vm, u8 thread_index, u8 is_ip4);
533 void tcp_flush_frames_to_output (u8 thread_index);
534 
536 tcp_end_seq (tcp_header_t * th, u32 len)
537 {
538  return th->seq_number + tcp_is_syn (th) + tcp_is_fin (th) + len;
539 }
540 
541 /* Modulo arithmetic for TCP sequence numbers */
542 #define seq_lt(_s1, _s2) ((i32)((_s1)-(_s2)) < 0)
543 #define seq_leq(_s1, _s2) ((i32)((_s1)-(_s2)) <= 0)
544 #define seq_gt(_s1, _s2) ((i32)((_s1)-(_s2)) > 0)
545 #define seq_geq(_s1, _s2) ((i32)((_s1)-(_s2)) >= 0)
546 #define seq_max(_s1, _s2) (seq_gt((_s1), (_s2)) ? (_s1) : (_s2))
548 /* Modulo arithmetic for timestamps */
549 #define timestamp_lt(_t1, _t2) ((i32)((_t1)-(_t2)) < 0)
550 #define timestamp_leq(_t1, _t2) ((i32)((_t1)-(_t2)) <= 0)
552 /**
553  * Our estimate of the number of bytes that have left the network
554  */
556 tcp_bytes_out (const tcp_connection_t * tc)
557 {
558  if (tcp_opts_sack_permitted (&tc->rcv_opts))
559  return tc->sack_sb.sacked_bytes + tc->sack_sb.lost_bytes;
560  else
561  return tc->rcv_dupacks * tc->snd_mss;
562 }
563 
564 /**
565  * Our estimate of the number of bytes in flight (pipe size)
566  */
569 {
570  int flight_size;
571 
572  flight_size = (int) (tc->snd_una_max - tc->snd_una) - tcp_bytes_out (tc)
573  + tc->snd_rxt_bytes;
574 
575  if (flight_size < 0)
576  {
577  if (0)
579  ("Negative: %u %u %u dupacks %u sacked bytes %u flags %d",
580  tc->snd_una_max - tc->snd_una, tcp_bytes_out (tc),
581  tc->snd_rxt_bytes, tc->rcv_dupacks, tc->sack_sb.sacked_bytes,
582  tc->rcv_opts.flags);
583  return 0;
584  }
585 
586  return flight_size;
587 }
588 
589 /**
590  * Initial cwnd as per RFC5681
591  */
594 {
595  if (tc->snd_mss > 2190)
596  return 2 * tc->snd_mss;
597  else if (tc->snd_mss > 1095)
598  return 3 * tc->snd_mss;
599  else
600  return 4 * tc->snd_mss;
601 }
602 
604 tcp_loss_wnd (const tcp_connection_t * tc)
605 {
606  return tc->snd_mss;
607 }
608 
611 {
612  return clib_min (tc->cwnd, tc->snd_wnd);
613 }
614 
617 {
618  u32 available_wnd = tcp_available_snd_wnd (tc);
619  int flight_size = (int) (tc->snd_nxt - tc->snd_una);
620 
621  if (available_wnd <= flight_size)
622  return 0;
623 
624  return available_wnd - flight_size;
625 }
626 
627 /**
628  * Estimate of how many bytes we can still push into the network
629  */
632 {
633  u32 available_wnd = tcp_available_snd_wnd (tc);
634  u32 flight_size = tcp_flight_size (tc);
635 
636  if (available_wnd <= flight_size)
637  return 0;
638 
639  return available_wnd - flight_size;
640 }
641 
644 {
645  if ((tc->flags & TCP_CONN_FINSNT) && tc->snd_una_max - tc->snd_una == 1)
646  return 1;
647  return 0;
648 }
649 
656 
658 
659 /* Made public for unit testing only */
660 void tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end);
662 
664 tcp_time_now (void)
665 {
666  return tcp_main.wrk_ctx[vlib_get_thread_index ()].time_now;
667 }
668 
670 tcp_set_time_now (u32 thread_index)
671 {
672  tcp_main.wrk_ctx[thread_index].time_now = clib_cpu_time_now ()
673  * tcp_main.tstamp_ticks_per_clock;
674  return tcp_main.wrk_ctx[thread_index].time_now;
675 }
676 
678 
683 
684 always_inline void
686 {
687  /* Reset flags, make sure ack is sent */
688  tc->flags = TCP_CONN_SNDACK;
689  vnet_buffer (b)->tcp.flags &= ~TCP_BUF_FLAG_DUPACK;
690 }
691 
692 always_inline void
693 tcp_timer_set (tcp_connection_t * tc, u8 timer_id, u32 interval)
694 {
695  ASSERT (tc->c_thread_index == vlib_get_thread_index ());
696  ASSERT (tc->timers[timer_id] == TCP_TIMER_HANDLE_INVALID);
697  tc->timers[timer_id] =
698  tw_timer_start_16t_2w_512sl (&tcp_main.
699  wrk_ctx[tc->c_thread_index].timer_wheel,
700  tc->c_c_index, timer_id, interval);
701 }
702 
703 always_inline void
704 tcp_timer_reset (tcp_connection_t * tc, u8 timer_id)
705 {
706  ASSERT (tc->c_thread_index == vlib_get_thread_index ());
707  if (tc->timers[timer_id] == TCP_TIMER_HANDLE_INVALID)
708  return;
709 
710  tw_timer_stop_16t_2w_512sl (&tcp_main.
711  wrk_ctx[tc->c_thread_index].timer_wheel,
712  tc->timers[timer_id]);
713  tc->timers[timer_id] = TCP_TIMER_HANDLE_INVALID;
714 }
715 
716 always_inline void
717 tcp_timer_update (tcp_connection_t * tc, u8 timer_id, u32 interval)
718 {
719  ASSERT (tc->c_thread_index == vlib_get_thread_index ());
720  if (tc->timers[timer_id] != TCP_TIMER_HANDLE_INVALID)
721  tw_timer_update_16t_2w_512sl (&tcp_main.
722  wrk_ctx[tc->c_thread_index].timer_wheel,
723  tc->timers[timer_id], interval);
724  else
725  tc->timers[timer_id] =
726  tw_timer_start_16t_2w_512sl (&tcp_main.
727  wrk_ctx[tc->c_thread_index].timer_wheel,
728  tc->c_c_index, timer_id, interval);
729 }
730 
731 always_inline void
733 {
734  ASSERT (tc->snd_una != tc->snd_una_max);
735  tcp_timer_set (tc, TCP_TIMER_RETRANSMIT,
736  clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
737 }
738 
739 always_inline void
741 {
742  tcp_timer_reset (tc, TCP_TIMER_RETRANSMIT);
743 }
744 
745 always_inline void
747 {
748  tcp_timer_update (tc, TCP_TIMER_RETRANSMIT,
749  clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
750 }
751 
752 always_inline void
754 {
755  /* Reuse RTO. It's backed off in handler */
756  tcp_timer_set (tc, TCP_TIMER_PERSIST,
757  clib_max (tc->rto * TCP_TO_TIMER_TICK,
759 }
760 
761 always_inline void
763 {
764  tcp_timer_update (tc, TCP_TIMER_PERSIST,
765  clib_max (tc->rto * TCP_TO_TIMER_TICK,
767 }
768 
769 always_inline void
771 {
772  tcp_timer_reset (tc, TCP_TIMER_PERSIST);
773 }
774 
775 always_inline void
777 {
778  if (tc->snd_una == tc->snd_una_max)
779  {
781  if (tc->snd_wnd < tc->snd_mss)
783  }
784  else
785  tcp_timer_update (tc, TCP_TIMER_RETRANSMIT,
786  clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
787 }
788 
791 {
792  return tc->timers[timer] != TCP_TIMER_HANDLE_INVALID;
793 }
794 
795 #define tcp_validate_txf_size(_tc, _a) \
796  ASSERT(_tc->state != TCP_STATE_ESTABLISHED \
797  || session_tx_fifo_max_dequeue (&_tc->connection) >= _a)
798 
799 void tcp_rcv_sacks (tcp_connection_t * tc, u32 ack);
800 u8 *tcp_scoreboard_replay (u8 * s, tcp_connection_t * tc, u8 verbose);
801 
803  const tcp_cc_algorithm_t * vft);
804 
806 
807 /**
808  * Push TCP header to buffer
809  *
810  * @param vm - vlib_main
811  * @param b - buffer to write the header to
812  * @param sp_net - source port net order
813  * @param dp_net - destination port net order
814  * @param seq - sequence number net order
815  * @param ack - ack number net order
816  * @param tcp_hdr_opts_len - header and options length in bytes
817  * @param flags - header flags
818  * @param wnd - window size
819  *
820  * @return - pointer to start of TCP header
821  */
822 always_inline void *
824  u32 ack, u8 tcp_hdr_opts_len, u8 flags,
825  u16 wnd)
826 {
827  tcp_header_t *th;
828 
829  th = vlib_buffer_push_uninit (b, tcp_hdr_opts_len);
830 
831  th->src_port = sp;
832  th->dst_port = dp;
833  th->seq_number = seq;
834  th->ack_number = ack;
835  th->data_offset_and_reserved = (tcp_hdr_opts_len >> 2) << 4;
836  th->flags = flags;
837  th->window = wnd;
838  th->checksum = 0;
839  th->urgent_pointer = 0;
840  return th;
841 }
842 
843 /**
844  * Push TCP header to buffer
845  *
846  * @param b - buffer to write the header to
847  * @param sp_net - source port net order
848  * @param dp_net - destination port net order
849  * @param seq - sequence number host order
850  * @param ack - ack number host order
851  * @param tcp_hdr_opts_len - header and options length in bytes
852  * @param flags - header flags
853  * @param wnd - window size
854  *
855  * @return - pointer to start of TCP header
856  */
857 always_inline void *
858 vlib_buffer_push_tcp (vlib_buffer_t * b, u16 sp_net, u16 dp_net, u32 seq,
859  u32 ack, u8 tcp_hdr_opts_len, u8 flags, u16 wnd)
860 {
861  return vlib_buffer_push_tcp_net_order (b, sp_net, dp_net,
862  clib_host_to_net_u32 (seq),
863  clib_host_to_net_u32 (ack),
864  tcp_hdr_opts_len, flags,
865  clib_host_to_net_u16 (wnd));
866 }
867 
868 #endif /* _vnet_tcp_h_ */
869 
870 /*
871  * fd.io coding-style-patch-verification: ON
872  *
873  * Local Variables:
874  * eval: (c-set-style "gnu")
875  * End:
876  */
tcp_main_t tcp_main
Definition: tcp.c:29
static vlib_cli_command_t trace
(constructor) VLIB_CLI_COMMAND (trace)
Definition: vlib_api_cli.c:862
#define CLIB_CACHE_LINE_ALIGN_MARK(mark)
Definition: cache.h:63
#define tcp_fastrecovery_1_smss_off(tc)
Definition: tcp.h:348
#define clib_min(x, y)
Definition: clib.h:289
void scoreboard_clear(sack_scoreboard_t *sb)
Definition: tcp_input.c:783
static void tcp_retransmit_timer_set(tcp_connection_t *tc)
Definition: tcp.h:733
void tcp_make_fin(tcp_connection_t *tc, vlib_buffer_t *b)
Convert buffer to FIN-ACK.
Definition: tcp_output.c:560
struct _sack_block sack_block_t
void tcp_cc_init_congestion(tcp_connection_t *tc)
Init loss recovery/fast recovery.
Definition: tcp_input.c:1029
struct _scoreboard_trace_elt scoreboard_trace_elt_t
void tcp_connection_timers_reset(tcp_connection_t *tc)
Stop all connection timers.
Definition: tcp.c:401
struct _transport_connection transport_connection_t
#define TCP_TO_TIMER_TICK
Definition: tcp.h:96
vlib_node_registration_t tcp4_output_node
(constructor) VLIB_REGISTER_NODE (tcp4_output_node)
Definition: tcp_output.c:2005
void scoreboard_init(sack_scoreboard_t *sb)
Definition: tcp_input.c:775
tcp_connection_t * tcp_connection_new(u8 thread_index)
Definition: tcp.c:248
void tcp_fast_retransmit(tcp_connection_t *tc)
Do fast retransmit.
Definition: tcp_output.c:1772
static u32 tcp_bytes_out(const tcp_connection_t *tc)
Our estimate of the number of bytes that have left the network.
Definition: tcp.h:557
static tcp_connection_t * tcp_connection_get_if_valid(u32 conn_index, u32 thread_index)
Definition: tcp.h:475
void tcp_connection_del(tcp_connection_t *tc)
Connection removal.
Definition: tcp.c:240
struct _sack_scoreboard sack_scoreboard_t
void tcp_update_sack_list(tcp_connection_t *tc, u32 start, u32 end)
Build SACK list as per RFC2018.
Definition: tcp_input.c:1429
static tcp_connection_t * tcp_half_open_connection_get(u32 conn_index)
Definition: tcp.h:512
sack_scoreboard_hole_t * scoreboard_last_hole(sack_scoreboard_t *sb)
Definition: tcp_input.c:583
sack_scoreboard_hole_t * scoreboard_next_hole(sack_scoreboard_t *sb, sack_scoreboard_hole_t *hole)
Definition: tcp_input.c:559
#define VLIB_BUFFER_PRE_DATA_SIZE
Definition: buffer.h:52
static_always_inline void clib_spinlock_unlock_if_init(clib_spinlock_t *p)
Definition: lock.h:98
struct _tcp_main tcp_main_t
vlib_node_registration_t tcp6_output_node
(constructor) VLIB_REGISTER_NODE (tcp6_output_node)
Definition: tcp_output.c:2026
static u64 clib_cpu_time_now(void)
Definition: time.h:73
timer_expiration_handler tcp_timer_retransmit_handler
u8 * format_tcp_scoreboard(u8 *s, va_list *args)
Definition: tcp.c:933
struct _tcp_lookup_dispatch tcp_lookup_dispatch_t
struct _tcp_connection tcp_connection_t
static u32 tcp_available_cc_snd_space(const tcp_connection_t *tc)
Estimate of how many bytes we can still push into the network.
Definition: tcp.h:632
static u32 tcp_available_snd_wnd(const tcp_connection_t *tc)
Definition: tcp.h:611
void tcp_fast_retransmit_sack(tcp_connection_t *tc)
Do fast retransmit with SACKs.
Definition: tcp_output.c:1652
static tcp_connection_t * tcp_get_connection_from_transport(transport_connection_t *tconn)
Definition: tcp.h:485
void tcp_connection_cleanup(tcp_connection_t *tc)
Cleans up connection state.
Definition: tcp.c:199
u8 *( format_function_t)(u8 *s, va_list *args)
Definition: format.h:48
void tcp_send_reset_w_pkt(tcp_connection_t *tc, vlib_buffer_t *pkt, u8 is_ip4)
Send reset without reusing existing buffer.
Definition: tcp_output.c:817
format_function_t format_tcp_flags
Definition: tcp.h:64
struct _tcp_header tcp_header_t
void tcp_connection_reset(tcp_connection_t *tc)
Notify session that connection has been reset.
Definition: tcp.c:265
unsigned char u8
Definition: types.h:56
struct _sack_scoreboard_hole sack_scoreboard_hole_t
double f64
Definition: types.h:142
void tcp_flush_frame_to_output(vlib_main_t *vm, u8 thread_index, u8 is_ip4)
Flush tx frame populated by retransmits and timer pops.
Definition: tcp_output.c:1009
u8 * tcp_scoreboard_replay(u8 *s, tcp_connection_t *tc, u8 verbose)
Definition: tcp.c:1737
i16 current_data
signed offset in data[], pre_data[] that we are currently processing.
Definition: buffer.h:104
#define tcp_is_fin(_th)
Definition: tcp_packet.h:90
sack_scoreboard_hole_t * scoreboard_get_hole(sack_scoreboard_t *sb, u32 index)
Definition: tcp_input.c:551
#define always_inline
Definition: clib.h:92
static u32 tcp_available_output_snd_space(const tcp_connection_t *tc)
Definition: tcp.h:617
static tcp_header_t * tcp_buffer_hdr(vlib_buffer_t *b)
Definition: tcp.h:445
static timer_callback_t * timers
Definition: timer.c:57
enum _tcp_state tcp_state_t
timer_expiration_handler tcp_timer_retransmit_syn_handler
static u32 tcp_time_now(void)
Definition: tcp.h:665
unsigned int u32
Definition: types.h:88
sack_scoreboard_hole_t * scoreboard_next_rxt_hole(sack_scoreboard_t *sb, sack_scoreboard_hole_t *start, u8 have_sent_1_smss, u8 *can_rescue, u8 *snd_limited)
Figure out the next hole to retransmit.
Definition: tcp_input.c:707
void tcp_api_reference(void)
Definition: tcp_api.c:109
static void tcp_timer_set(tcp_connection_t *tc, u8 timer_id, u32 interval)
Definition: tcp.h:694
struct tcp_worker_ctx_ tcp_worker_ctx_t
#define pool_elt_at_index(p, i)
Returns pointer to element at given index.
Definition: pool.h:461
timer_expiration_handler tcp_timer_persist_handler
u32 tcp_push_header(tcp_connection_t *tconn, vlib_buffer_t *b)
Definition: tcp_output.c:1157
u32 tcp_sack_list_bytes(tcp_connection_t *tc)
Definition: tcp_input.c:1483
static 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)
Push TCP header to buffer.
Definition: tcp.h:824
void tcp_retransmit_first_unacked(tcp_connection_t *tc)
Retransmit first unacked segment.
Definition: tcp_output.c:1629
void tcp_rcv_sacks(tcp_connection_t *tc, u32 ack)
Definition: tcp_input.c:817
clib_error_t * vnet_tcp_enable_disable(vlib_main_t *vm, u8 is_en)
Definition: tcp.c:1328
void tcp_send_syn(tcp_connection_t *tc)
Send SYN.
Definition: tcp_output.c:973
unsigned short u16
Definition: types.h:57
sack_scoreboard_hole_t * scoreboard_prev_hole(sack_scoreboard_t *sb, sack_scoreboard_hole_t *hole)
Definition: tcp_input.c:567
#define TCP_TIMER_HANDLE_INVALID
Definition: tcp.h:93
void tcp_fast_retransmit_no_sack(tcp_connection_t *tc)
Fast retransmit without SACK info.
Definition: tcp_output.c:1735
static u32 tcp_flight_size(const tcp_connection_t *tc)
Our estimate of the number of bytes in flight (pipe size)
Definition: tcp.h:569
#define PREDICT_FALSE(x)
Definition: clib.h:105
void tcp_cc_algo_register(tcp_cc_algorithm_type_e type, const tcp_cc_algorithm_t *vft)
Definition: tcp.c:515
void( timer_expiration_handler)(u32 index)
Definition: tcp.h:86
enum _tcp_cc_ack_t tcp_cc_ack_t
static void tcp_timer_reset(tcp_connection_t *tc, u8 timer_id)
Definition: tcp.h:705
enum _tcp_error tcp_error_t
static 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)
Push TCP header to buffer.
Definition: tcp.h:859
int tcp_configure_v4_source_address_range(vlib_main_t *vm, ip4_address_t *start, ip4_address_t *end, u32 table_id)
Configure an ipv4 source address range.
Definition: tcp.c:1421
static_always_inline uword vlib_get_thread_index(void)
Definition: threads.h:221
void tcp_send_reset(tcp_connection_t *tc)
Build and set reset packet for connection.
Definition: tcp_output.c:896
void tcp_punt_unknown(vlib_main_t *vm, u8 is_ip4, u8 is_add)
Definition: tcp.c:1346
format_function_t format_tcp_state
Definition: tcp.h:63
#define clib_warning(format, args...)
Definition: error.h:59
enum _tcp_timers tcp_timers_e
static void tcp_connection_force_ack(tcp_connection_t *tc, vlib_buffer_t *b)
Definition: tcp.h:686
int tcp_half_open_connection_cleanup(tcp_connection_t *tc)
Try to cleanup half-open connection.
Definition: tcp.c:170
u32 fib_node_index_t
A typedef of a node index.
Definition: fib_types.h:30
void tcp_connection_timers_init(tcp_connection_t *tc)
Initialize all connection timers as invalid.
Definition: tcp.c:384
void tcp_make_synack(tcp_connection_t *ts, vlib_buffer_t *b)
Convert buffer to SYN-ACK.
Definition: tcp_output.c:603
void tcp_flush_frames_to_output(u8 thread_index)
Flush v4 and v6 tcp and ip-lookup tx frames for thread index.
Definition: tcp_output.c:1044
#define pool_is_free_index(P, I)
Use free bitmap to query whether given index is free.
Definition: pool.h:270
format_function_t format_tcp_rcv_sacks
Definition: tcp.h:66
vlib_node_registration_t tcp6_input_node
(constructor) VLIB_REGISTER_NODE (tcp6_input_node)
Definition: tcp_input.c:3386
fib_node_index_t tcp_lookup_rmt_in_fib(tcp_connection_t *tc)
void tcp_make_ack(tcp_connection_t *ts, vlib_buffer_t *b)
Convert buffer to ACK.
Definition: tcp_output.c:545
static void tcp_timer_update(tcp_connection_t *tc, u8 timer_id, u32 interval)
Definition: tcp.h:718
#define ASSERT(truth)
enum _tcp_cc_algorithm_type tcp_cc_algorithm_type_e
enum _tcp_connection_flag_bits tcp_connection_flag_bits_e
vhost_vring_state_t state
Definition: vhost-user.h:82
void tcp_connection_init_vars(tcp_connection_t *tc)
Initialize tcp connection variables.
Definition: tcp.c:560
u8 * format_tcp_connection(u8 *s, va_list *args)
Definition: tcp.c:822
static u32 tcp_end_seq(tcp_header_t *th, u32 len)
Definition: tcp.h:537
static void init(void)
Definition: client.c:105
struct _tcp_cc_algorithm tcp_cc_algorithm_t
Definition: tcp.h:252
#define clib_max(x, y)
Definition: clib.h:282
struct _vlib_node_registration vlib_node_registration_t
#define tcp_is_syn(_th)
Definition: tcp_packet.h:89
void tcp_update_snd_mss(tcp_connection_t *tc)
Update snd_mss to reflect the effective segment size that we can send by taking into account all TCP ...
Definition: tcp_output.c:410
static void tcp_persist_timer_update(tcp_connection_t *tc)
Definition: tcp.h:763
static void * vlib_buffer_push_uninit(vlib_buffer_t *b, u8 size)
Prepend uninitialized data to buffer.
Definition: buffer.h:299
vlib_node_registration_t tcp4_input_node
(constructor) VLIB_REGISTER_NODE (tcp4_input_node)
Definition: tcp_input.c:3363
tcp_cc_algorithm_t * tcp_cc_algo_get(tcp_cc_algorithm_type_e type)
Definition: tcp.c:525
static u32 tcp_initial_cwnd(const tcp_connection_t *tc)
Initial cwnd as per RFC5681.
Definition: tcp.h:594
#define foreach_tcp_fsm_state
TCP FSM state definitions as per RFC793.
Definition: tcp.h:42
void tcp_send_fin(tcp_connection_t *tc)
Send FIN.
Definition: tcp_output.c:1057
#define foreach_tcp_connection_flag
TCP connection flags.
Definition: tcp.h:114
#define foreach_tcp_timer
TCP timers.
Definition: tcp.h:69
static u32 tcp_set_time_now(u32 thread_index)
Definition: tcp.h:671
static u8 tcp_is_lost_fin(tcp_connection_t *tc)
Definition: tcp.h:644
sack_scoreboard_hole_t * scoreboard_first_hole(sack_scoreboard_t *sb)
Definition: tcp_input.c:575
static void tcp_retransmit_timer_update(tcp_connection_t *tc)
Definition: tcp.h:777
void tcp_init_snd_vars(tcp_connection_t *tc)
Initialize connection send variables.
Definition: tcp.c:536
void tcp_connection_close(tcp_connection_t *tc)
Begin connection closing procedure.
Definition: tcp.c:314
static void tcp_retransmit_timer_force_update(tcp_connection_t *tc)
Definition: tcp.h:747
#define vnet_buffer(b)
Definition: buffer.h:360
static tcp_connection_t * tcp_connection_get(u32 conn_index, u32 thread_index)
Definition: tcp.h:466
void tcp_update_rto(tcp_connection_t *tc)
Definition: tcp_input.c:431
void tcp_init_mss(tcp_connection_t *tc)
Definition: tcp_output.c:423
u8 data[0]
Packet data.
Definition: buffer.h:172
#define foreach_tcp_buf_flag
TCP buffer flags.
Definition: tcp.h:141
enum _tcp_connection_flag tcp_connection_flags_e
format_function_t format_tcp_sacks
Definition: tcp.h:65
#define TCP_TIMER_PERSIST_MIN
Definition: tcp.h:105
#define tcp_opts_sack_permitted(_to)
Definition: tcp_packet.h:160
static u32 tcp_loss_wnd(const tcp_connection_t *tc)
Definition: tcp.h:605
int tcp_configure_v6_source_address_range(vlib_main_t *vm, ip6_address_t *start, ip6_address_t *end, u32 table_id)
Configure an ipv6 source address range.
Definition: tcp.c:1513
u32 flags
Definition: vhost-user.h:77
static void tcp_persist_timer_set(tcp_connection_t *tc)
Definition: tcp.h:754
static tcp_main_t * vnet_get_tcp_main()
Definition: tcp.h:439
static void tcp_cong_recovery_off(tcp_connection_t *tc)
Definition: tcp.h:354
timer_expiration_handler tcp_timer_delack_handler
static_always_inline void clib_spinlock_lock_if_init(clib_spinlock_t *p)
Definition: lock.h:82
static void tcp_retransmit_timer_reset(tcp_connection_t *tc)
Definition: tcp.h:741
void tcp_cc_fastrecovery_exit(tcp_connection_t *tc)
Definition: tcp_input.c:1050
static u8 tcp_timer_is_active(tcp_connection_t *tc, tcp_timers_e timer)
Definition: tcp.h:791
static tcp_connection_t * tcp_listener_get(u32 tli)
Definition: tcp.h:506
static void tcp_persist_timer_reset(tcp_connection_t *tc)
Definition: tcp.h:771