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:
7 * http://www.apache.org/licenses/LICENSE-2.0
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.
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>
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
34 #define TCP_DUPACK_THRESHOLD 3
35 #define TCP_MAX_RX_FIFO_SIZE 32 << 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 */
41 /** TCP FSM state definitions as per RFC793. */
42 #define foreach_tcp_fsm_state \
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")
55 typedef enum _tcp_state
57 #define _(sym, str) TCP_STATE_##sym,
63 format_function_t format_tcp_state;
64 format_function_t format_tcp_flags;
65 format_function_t format_tcp_sacks;
66 format_function_t format_tcp_rcv_sacks;
69 #define foreach_tcp_timer \
70 _(RETRANSMIT, "RETRANSMIT") \
71 _(DELACK, "DELAYED ACK") \
72 _(PERSIST, "PERSIST") \
74 _(WAITCLOSE, "WAIT CLOSE") \
75 _(RETRANSMIT_SYN, "RETRANSMIT SYN") \
76 _(ESTABLISH, "ESTABLISH")
78 typedef enum _tcp_timers
80 #define _(sym, str) TCP_TIMER_##sym,
86 typedef void (timer_expiration_handler) (u32 index);
88 extern timer_expiration_handler tcp_timer_delack_handler;
89 extern timer_expiration_handler tcp_timer_retransmit_handler;
90 extern timer_expiration_handler tcp_timer_persist_handler;
91 extern timer_expiration_handler tcp_timer_retransmit_syn_handler;
93 #define TCP_TIMER_HANDLE_INVALID ((u32) ~0)
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 */
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 */
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 _(FRXT_PENDING, "Fast-retransmit pending") \
124 _(FRXT_FIRST, "Fast-retransmit first again") \
125 _(DEQ_PENDING, "Pending dequeue acked") \
127 typedef enum _tcp_connection_flag_bits
129 #define _(sym, str) TCP_CONN_##sym##_BIT,
130 foreach_tcp_connection_flag
133 } tcp_connection_flag_bits_e;
135 typedef enum _tcp_connection_flag
137 #define _(sym, str) TCP_CONN_##sym = 1 << TCP_CONN_##sym##_BIT,
138 foreach_tcp_connection_flag
141 } tcp_connection_flags_e;
143 /** TCP buffer flags */
144 #define foreach_tcp_buf_flag \
145 _ (ACK) /**< Sending ACK. */ \
146 _ (DUPACK) /**< Sending DUPACK. */ \
150 #define _(f) TCP_BUF_BIT_##f,
158 #define _(f) TCP_BUF_FLAG_##f = 1 << TCP_BUF_BIT_##f,
163 #define TCP_SCOREBOARD_TRACE (0)
164 #define TCP_MAX_SACK_BLOCKS 256 /**< Max number of SACK blocks stored */
165 #define TCP_INVALID_SACK_HOLE_INDEX ((u32)~0)
167 typedef struct _scoreboard_trace_elt
174 } scoreboard_trace_elt_t;
176 typedef struct _sack_scoreboard_hole
178 u32 next; /**< Index for next entry in linked list */
179 u32 prev; /**< Index for previous entry in linked list */
180 u32 start; /**< Start sequence number */
181 u32 end; /**< End sequence number */
182 u8 is_lost; /**< Mark hole as lost */
183 } sack_scoreboard_hole_t;
185 typedef struct _sack_scoreboard
187 sack_scoreboard_hole_t *holes; /**< Pool of holes */
188 u32 head; /**< Index of first entry */
189 u32 tail; /**< Index of last entry */
190 u32 sacked_bytes; /**< Number of bytes sacked in sb */
191 u32 last_sacked_bytes; /**< Number of bytes last sacked */
192 u32 last_bytes_delivered; /**< Number of sack bytes delivered */
193 u32 snd_una_adv; /**< Bytes to add to snd_una */
194 u32 high_sacked; /**< Highest byte sacked (fack) */
195 u32 high_rxt; /**< Highest retransmitted sequence */
196 u32 rescue_rxt; /**< Rescue sequence number */
197 u32 lost_bytes; /**< Bytes lost as per RFC6675 */
198 u32 cur_rxt_hole; /**< Retransmitting from this hole */
200 #if TCP_SCOREBOARD_TRACE
201 scoreboard_trace_elt_t *trace;
206 #if TCP_SCOREBOARD_TRACE
207 #define tcp_scoreboard_trace_add(_tc, _ack) \
209 static u64 _group = 0; \
210 sack_scoreboard_t *_sb = &_tc->sack_sb; \
211 sack_block_t *_sack, *_sacks; \
212 scoreboard_trace_elt_t *_elt; \
215 _sacks = _tc->rcv_opts.sacks; \
216 for (i = 0; i < vec_len (_sacks); i++) \
218 _sack = &_sacks[i]; \
219 vec_add2 (_sb->trace, _elt, 1); \
220 _elt->start = _sack->start; \
221 _elt->end = _sack->end; \
222 _elt->ack = _elt->end == _ack ? _ack : 0; \
223 _elt->snd_una_max = _elt->end == _ack ? _tc->snd_una_max : 0; \
224 _elt->group = _group; \
228 #define tcp_scoreboard_trace_add(_tc, _ack)
231 sack_scoreboard_hole_t *scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
232 sack_scoreboard_hole_t *
233 start, u8 have_sent_1_smss,
236 sack_scoreboard_hole_t *scoreboard_get_hole (sack_scoreboard_t * sb,
239 sack_scoreboard_hole_t *scoreboard_next_hole (sack_scoreboard_t * sb,
240 sack_scoreboard_hole_t * hole);
241 sack_scoreboard_hole_t *scoreboard_prev_hole (sack_scoreboard_t * sb,
242 sack_scoreboard_hole_t * hole);
243 sack_scoreboard_hole_t *scoreboard_first_hole (sack_scoreboard_t * sb);
244 sack_scoreboard_hole_t *scoreboard_last_hole (sack_scoreboard_t * sb);
245 void scoreboard_clear (sack_scoreboard_t * sb);
246 void scoreboard_init (sack_scoreboard_t * sb);
247 u8 *format_tcp_scoreboard (u8 * s, va_list * args);
249 typedef enum _tcp_cc_algorithm_type
252 } tcp_cc_algorithm_type_e;
254 typedef struct _tcp_cc_algorithm tcp_cc_algorithm_t;
256 typedef enum _tcp_cc_ack_t
263 typedef struct _tcp_connection
265 transport_connection_t connection; /**< Common transport data. First! */
267 u8 state; /**< TCP state as per tcp_state_t */
268 u16 flags; /**< Connection flags (see tcp_conn_flags_e) */
269 u32 timers[TCP_N_TIMERS]; /**< Timer handles into timer wheel */
273 /** Send sequence variables RFC793 */
274 u32 snd_una; /**< oldest unacknowledged sequence number */
275 u32 snd_una_max; /**< newest unacknowledged sequence number + 1*/
276 u32 snd_wnd; /**< send window */
277 u32 snd_wl1; /**< seq number used for last snd.wnd update */
278 u32 snd_wl2; /**< ack number used for last snd.wnd update */
279 u32 snd_nxt; /**< next seq number to be sent */
280 u16 snd_mss; /**< Effective send max seg (data) size */
282 /** Receive sequence variables RFC793 */
283 u32 rcv_nxt; /**< next sequence number expected */
284 u32 rcv_wnd; /**< receive window we expect */
286 u32 rcv_las; /**< rcv_nxt at last ack sent/rcv_wnd update */
287 u32 iss; /**< initial sent sequence */
288 u32 irs; /**< initial remote sequence */
291 u8 snd_opts_len; /**< Tx options len */
292 u8 rcv_wscale; /**< Window scale to advertise to peer */
293 u8 snd_wscale; /**< Window scale to use when sending */
294 u32 tsval_recent; /**< Last timestamp received */
295 u32 tsval_recent_age; /**< When last updated tstamp_recent*/
296 tcp_options_t snd_opts; /**< Tx options for connection */
297 tcp_options_t rcv_opts; /**< Rx options for connection */
299 sack_block_t *snd_sacks; /**< Vector of SACKs to send. XXX Fixed size? */
300 sack_scoreboard_t sack_sb; /**< SACK "scoreboard" that tracks holes */
302 u16 rcv_dupacks; /**< Number of DUPACKs received */
303 u8 snt_dupacks; /**< Number of DUPACKs sent in a burst */
305 /* Congestion control */
306 u32 cwnd; /**< Congestion window */
307 u32 cwnd_acc_bytes; /**< Bytes accumulated for cwnd increment */
308 u32 ssthresh; /**< Slow-start threshold */
309 u32 prev_ssthresh; /**< ssthresh before congestion */
310 u32 prev_cwnd; /**< ssthresh before congestion */
311 u32 bytes_acked; /**< Bytes acknowledged by current segment */
312 u32 burst_acked; /**< Bytes acknowledged in current burst */
313 u32 snd_rxt_bytes; /**< Retransmitted bytes */
314 u32 snd_rxt_ts; /**< Timestamp when first packet is retransmitted */
315 u32 tsecr_last_ack; /**< Timestamp echoed to us in last healthy ACK */
316 u32 snd_congestion; /**< snd_una_max when congestion is detected */
317 tcp_cc_algorithm_t *cc_algo; /**< Congestion control algorithm */
320 u32 rto; /**< Retransmission timeout */
321 u32 rto_boff; /**< Index for RTO backoff */
322 u32 srtt; /**< Smoothed RTT */
323 u32 rttvar; /**< Smoothed mean RTT difference. Approximates variance */
324 u32 rtt_seq; /**< Sequence number for tracked ACK */
325 f64 rtt_ts; /**< Timestamp for tracked ACK */
326 f64 mrtt_us; /**< High precision mrtt from tracked acks */
328 u16 mss; /**< Our max seg size that includes options */
329 u32 limited_transmit; /**< snd_nxt when limited transmit starts */
330 u32 last_fib_check; /**< Last time we checked fib route for peer */
331 u32 sw_if_index; /**< Interface for the connection */
334 struct _tcp_cc_algorithm
336 void (*rcv_ack) (tcp_connection_t * tc);
337 void (*rcv_cong_ack) (tcp_connection_t * tc, tcp_cc_ack_t ack);
338 void (*congestion) (tcp_connection_t * tc);
339 void (*recovered) (tcp_connection_t * tc);
340 void (*init) (tcp_connection_t * tc);
343 #define tcp_fastrecovery_on(tc) (tc)->flags |= TCP_CONN_FAST_RECOVERY
344 #define tcp_fastrecovery_off(tc) (tc)->flags &= ~TCP_CONN_FAST_RECOVERY
345 #define tcp_recovery_on(tc) (tc)->flags |= TCP_CONN_RECOVERY
346 #define tcp_recovery_off(tc) (tc)->flags &= ~TCP_CONN_RECOVERY
347 #define tcp_in_fastrecovery(tc) ((tc)->flags & TCP_CONN_FAST_RECOVERY)
348 #define tcp_in_recovery(tc) ((tc)->flags & (TCP_CONN_RECOVERY))
349 #define tcp_in_slowstart(tc) (tc->cwnd < tc->ssthresh)
350 #define tcp_fastrecovery_sent_1_smss(tc) ((tc)->flags & TCP_CONN_FR_1_SMSS)
351 #define tcp_fastrecovery_1_smss_on(tc) ((tc)->flags |= TCP_CONN_FR_1_SMSS)
352 #define tcp_fastrecovery_1_smss_off(tc) ((tc)->flags &= ~TCP_CONN_FR_1_SMSS)
353 #define tcp_fastrecovery_first(tc) ((tc)->flags & TCP_CONN_FRXT_FIRST)
354 #define tcp_fastrecovery_first_on(tc) ((tc)->flags |= TCP_CONN_FRXT_FIRST)
355 #define tcp_fastrecovery_first_off(tc) ((tc)->flags &= ~TCP_CONN_FRXT_FIRST)
357 #define tcp_in_cong_recovery(tc) ((tc)->flags & \
358 (TCP_CONN_FAST_RECOVERY | TCP_CONN_RECOVERY))
361 tcp_cong_recovery_off (tcp_connection_t * tc)
363 tc->flags &= ~(TCP_CONN_FAST_RECOVERY | TCP_CONN_RECOVERY);
364 tcp_fastrecovery_1_smss_off (tc);
365 tcp_fastrecovery_first_off (tc);
368 typedef enum _tcp_error
370 #define tcp_error(n,s) TCP_ERROR_##n,
371 #include <vnet/tcp/tcp_error.def>
376 typedef struct _tcp_lookup_dispatch
379 } tcp_lookup_dispatch_t;
381 typedef struct tcp_worker_ctx_
383 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
384 u32 time_now; /**< worker time */
385 tw_timer_wheel_16t_2w_512sl_t timer_wheel; /**< worker timer wheel */
386 u32 *tx_buffers; /**< tx buffer free list */
387 vlib_frame_t *tx_frames[2]; /**< tx frames for tcp 4/6
389 vlib_frame_t *ip_lookup_tx_frames[2]; /**< tx frames for ip 4/6
391 u32 *pending_fast_rxt; /**< vector of connections
393 u32 *ongoing_fast_rxt; /**< vector of connections
394 now doing fast rxt */
395 u32 *postponed_fast_rxt; /**< vector of connections
396 that will do fast rxt */
397 u32 *pending_deq_acked;
398 vlib_main_t *vm; /**< pointer to vm */
400 CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
401 u8 cached_opts[40]; /**< cached 'on the wire'
402 options for bursts */
406 typedef struct _tcp_main
408 /* Per-worker thread tcp connection pools */
409 tcp_connection_t **connections;
411 /* Pool of listeners. */
412 tcp_connection_t *listener_pool;
414 /** Dispatch table by state and flags */
415 tcp_lookup_dispatch_t dispatch_table[TCP_N_STATES][64];
417 u8 log2_tstamp_clocks_per_tick;
418 f64 tstamp_ticks_per_clock;
420 /** per-worker context */
421 tcp_worker_ctx_t *wrk_ctx;
423 /* Pool of half-open connections on which we've sent a SYN */
424 tcp_connection_t *half_open_connections;
425 clib_spinlock_t half_open_lock;
427 /* Congestion control algorithms registered */
428 tcp_cc_algorithm_t *cc_algos;
430 /** vlib buffer size */
431 u32 bytes_per_buffer;
437 /* Flag that indicates if stack is on or off */
440 /** Max rx fifo size for a session. It is used in to compute the
441 * rfc 7323 window scaling factor */
444 /** Number of preallocated connections */
445 u32 preallocated_connections;
446 u32 preallocated_half_open_connections;
448 /** Vectors of src addresses. Optional unless one needs > 63K active-opens */
449 ip4_address_t *ip4_src_addresses;
450 u32 last_v4_address_rotor;
451 u32 last_v6_address_rotor;
452 ip6_address_t *ip6_src_addresses;
454 /** Enable tx pacing for new connections */
460 /** fault-injection */
461 f64 buffer_fail_fraction;
464 extern tcp_main_t tcp_main;
465 extern vlib_node_registration_t tcp4_input_node;
466 extern vlib_node_registration_t tcp6_input_node;
467 extern vlib_node_registration_t tcp4_output_node;
468 extern vlib_node_registration_t tcp6_output_node;
470 always_inline tcp_main_t *
476 always_inline tcp_worker_ctx_t *
477 tcp_get_worker (u32 thread_index)
479 return &tcp_main.wrk_ctx[thread_index];
482 always_inline tcp_header_t *
483 tcp_buffer_hdr (vlib_buffer_t * b)
485 ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
486 return (tcp_header_t *) (b->data + b->current_data
487 + vnet_buffer (b)->tcp.hdr_offset);
490 #if (VLIB_BUFFER_TRACE_TRAJECTORY)
491 #define tcp_trajectory_add_start(b, start) \
493 (*vlib_buffer_trace_trajectory_cb) (b, start); \
496 #define tcp_trajectory_add_start(b, start)
499 clib_error_t *vnet_tcp_enable_disable (vlib_main_t * vm, u8 is_en);
501 void tcp_punt_unknown (vlib_main_t * vm, u8 is_ip4, u8 is_add);
503 always_inline tcp_connection_t *
504 tcp_connection_get (u32 conn_index, u32 thread_index)
507 (pool_is_free_index (tcp_main.connections[thread_index], conn_index)))
509 return pool_elt_at_index (tcp_main.connections[thread_index], conn_index);
512 always_inline tcp_connection_t *
513 tcp_connection_get_if_valid (u32 conn_index, u32 thread_index)
515 if (tcp_main.connections[thread_index] == 0)
517 if (pool_is_free_index (tcp_main.connections[thread_index], conn_index))
519 return pool_elt_at_index (tcp_main.connections[thread_index], conn_index);
522 always_inline tcp_connection_t *
523 tcp_get_connection_from_transport (transport_connection_t * tconn)
525 return (tcp_connection_t *) tconn;
528 void tcp_connection_close (tcp_connection_t * tc);
529 void tcp_connection_cleanup (tcp_connection_t * tc);
530 void tcp_connection_del (tcp_connection_t * tc);
531 int tcp_half_open_connection_cleanup (tcp_connection_t * tc);
532 tcp_connection_t *tcp_connection_new (u8 thread_index);
533 void tcp_connection_reset (tcp_connection_t * tc);
534 int tcp_configure_v4_source_address_range (vlib_main_t * vm,
535 ip4_address_t * start,
536 ip4_address_t * end, u32 table_id);
537 int tcp_configure_v6_source_address_range (vlib_main_t * vm,
538 ip6_address_t * start,
539 ip6_address_t * end, u32 table_id);
540 void tcp_api_reference (void);
541 u8 *format_tcp_connection (u8 * s, va_list * args);
543 always_inline tcp_connection_t *
544 tcp_listener_get (u32 tli)
546 return pool_elt_at_index (tcp_main.listener_pool, tli);
549 always_inline tcp_connection_t *
550 tcp_half_open_connection_get (u32 conn_index)
552 tcp_connection_t *tc = 0;
553 clib_spinlock_lock_if_init (&tcp_main.half_open_lock);
554 if (!pool_is_free_index (tcp_main.half_open_connections, conn_index))
555 tc = pool_elt_at_index (tcp_main.half_open_connections, conn_index);
556 clib_spinlock_unlock_if_init (&tcp_main.half_open_lock);
560 void tcp_make_ack (tcp_connection_t * ts, vlib_buffer_t * b);
561 void tcp_make_fin (tcp_connection_t * tc, vlib_buffer_t * b);
562 void tcp_make_synack (tcp_connection_t * ts, vlib_buffer_t * b);
563 void tcp_send_reset_w_pkt (tcp_connection_t * tc, vlib_buffer_t * pkt,
565 void tcp_send_reset (tcp_connection_t * tc);
566 void tcp_send_syn (tcp_connection_t * tc);
567 void tcp_send_fin (tcp_connection_t * tc);
568 void tcp_init_mss (tcp_connection_t * tc);
569 void tcp_update_burst_snd_vars (tcp_connection_t * tc);
570 void tcp_update_rto (tcp_connection_t * tc);
571 void tcp_flush_frame_to_output (tcp_worker_ctx_t * wrk, u8 is_ip4);
572 void tcp_flush_frames_to_output (tcp_worker_ctx_t * wrk);
573 void tcp_program_fastretransmit (tcp_worker_ctx_t * wrk,
574 tcp_connection_t * tc);
575 void tcp_do_fastretransmits (tcp_worker_ctx_t * wrk);
578 tcp_end_seq (tcp_header_t * th, u32 len)
580 return th->seq_number + tcp_is_syn (th) + tcp_is_fin (th) + len;
583 /* Modulo arithmetic for TCP sequence numbers */
584 #define seq_lt(_s1, _s2) ((i32)((_s1)-(_s2)) < 0)
585 #define seq_leq(_s1, _s2) ((i32)((_s1)-(_s2)) <= 0)
586 #define seq_gt(_s1, _s2) ((i32)((_s1)-(_s2)) > 0)
587 #define seq_geq(_s1, _s2) ((i32)((_s1)-(_s2)) >= 0)
588 #define seq_max(_s1, _s2) (seq_gt((_s1), (_s2)) ? (_s1) : (_s2))
590 /* Modulo arithmetic for timestamps */
591 #define timestamp_lt(_t1, _t2) ((i32)((_t1)-(_t2)) < 0)
592 #define timestamp_leq(_t1, _t2) ((i32)((_t1)-(_t2)) <= 0)
595 * Our estimate of the number of bytes that have left the network
598 tcp_bytes_out (const tcp_connection_t * tc)
600 if (tcp_opts_sack_permitted (&tc->rcv_opts))
601 return tc->sack_sb.sacked_bytes + tc->sack_sb.lost_bytes;
603 return tc->rcv_dupacks * tc->snd_mss;
607 * Our estimate of the number of bytes in flight (pipe size)
610 tcp_flight_size (const tcp_connection_t * tc)
614 flight_size = (int) (tc->snd_una_max - tc->snd_una) - tcp_bytes_out (tc)
621 ("Negative: %u %u %u dupacks %u sacked bytes %u flags %d",
622 tc->snd_una_max - tc->snd_una, tcp_bytes_out (tc),
623 tc->snd_rxt_bytes, tc->rcv_dupacks, tc->sack_sb.sacked_bytes,
632 * Initial cwnd as per RFC5681
635 tcp_initial_cwnd (const tcp_connection_t * tc)
637 if (tc->snd_mss > 2190)
638 return 2 * tc->snd_mss;
639 else if (tc->snd_mss > 1095)
640 return 3 * tc->snd_mss;
642 return 4 * tc->snd_mss;
646 tcp_loss_wnd (const tcp_connection_t * tc)
652 tcp_available_snd_wnd (const tcp_connection_t * tc)
654 return clib_min (tc->cwnd, tc->snd_wnd);
658 tcp_available_output_snd_space (const tcp_connection_t * tc)
660 u32 available_wnd = tcp_available_snd_wnd (tc);
661 int flight_size = (int) (tc->snd_nxt - tc->snd_una);
663 if (available_wnd <= flight_size)
666 return available_wnd - flight_size;
670 * Estimate of how many bytes we can still push into the network
673 tcp_available_cc_snd_space (const tcp_connection_t * tc)
675 u32 available_wnd = tcp_available_snd_wnd (tc);
676 u32 flight_size = tcp_flight_size (tc);
678 if (available_wnd <= flight_size)
681 return available_wnd - flight_size;
685 tcp_is_lost_fin (tcp_connection_t * tc)
687 if ((tc->flags & TCP_CONN_FINSNT) && tc->snd_una_max - tc->snd_una == 1)
692 u32 tcp_snd_space (tcp_connection_t * tc);
693 int tcp_retransmit_first_unacked (tcp_worker_ctx_t * wrk,
694 tcp_connection_t * tc);
695 int tcp_fast_retransmit_no_sack (tcp_worker_ctx_t * wrk,
696 tcp_connection_t * tc, u32 burst_size);
697 int tcp_fast_retransmit_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
699 int tcp_fast_retransmit (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
701 void tcp_cc_init_congestion (tcp_connection_t * tc);
702 void tcp_cc_fastrecovery_exit (tcp_connection_t * tc);
704 fib_node_index_t tcp_lookup_rmt_in_fib (tcp_connection_t * tc);
706 /* Made public for unit testing only */
707 void tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end);
708 u32 tcp_sack_list_bytes (tcp_connection_t * tc);
713 return tcp_main.wrk_ctx[vlib_get_thread_index ()].time_now;
717 tcp_time_now_w_thread (u32 thread_index)
719 return tcp_main.wrk_ctx[thread_index].time_now;
723 tcp_time_now_us (u32 thread_index)
725 return transport_time_now (thread_index);
729 tcp_set_time_now (tcp_worker_ctx_t * wrk)
731 wrk->time_now = clib_cpu_time_now () * tcp_main.tstamp_ticks_per_clock;
732 return wrk->time_now;
735 u32 tcp_push_header (tcp_connection_t * tconn, vlib_buffer_t * b);
737 void tcp_connection_timers_init (tcp_connection_t * tc);
738 void tcp_connection_timers_reset (tcp_connection_t * tc);
739 void tcp_init_snd_vars (tcp_connection_t * tc);
740 void tcp_connection_init_vars (tcp_connection_t * tc);
741 void tcp_connection_tx_pacer_update (tcp_connection_t * tc);
742 void tcp_connection_tx_pacer_reset (tcp_connection_t * tc, u32 window,
746 tcp_cc_rcv_ack (tcp_connection_t * tc)
748 tc->cc_algo->rcv_ack (tc);
749 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
750 tcp_connection_tx_pacer_update (tc);
754 tcp_connection_force_ack (tcp_connection_t * tc, vlib_buffer_t * b)
756 /* Reset flags, make sure ack is sent */
757 tc->flags = TCP_CONN_SNDACK;
758 vnet_buffer (b)->tcp.flags &= ~TCP_BUF_FLAG_DUPACK;
762 tcp_timer_set (tcp_connection_t * tc, u8 timer_id, u32 interval)
764 ASSERT (tc->c_thread_index == vlib_get_thread_index ());
765 ASSERT (tc->timers[timer_id] == TCP_TIMER_HANDLE_INVALID);
766 tc->timers[timer_id] =
767 tw_timer_start_16t_2w_512sl (&tcp_main.
768 wrk_ctx[tc->c_thread_index].timer_wheel,
769 tc->c_c_index, timer_id, interval);
773 tcp_timer_reset (tcp_connection_t * tc, u8 timer_id)
775 ASSERT (tc->c_thread_index == vlib_get_thread_index ());
776 if (tc->timers[timer_id] == TCP_TIMER_HANDLE_INVALID)
779 tw_timer_stop_16t_2w_512sl (&tcp_main.
780 wrk_ctx[tc->c_thread_index].timer_wheel,
781 tc->timers[timer_id]);
782 tc->timers[timer_id] = TCP_TIMER_HANDLE_INVALID;
786 tcp_timer_update (tcp_connection_t * tc, u8 timer_id, u32 interval)
788 ASSERT (tc->c_thread_index == vlib_get_thread_index ());
789 if (tc->timers[timer_id] != TCP_TIMER_HANDLE_INVALID)
790 tw_timer_update_16t_2w_512sl (&tcp_main.
791 wrk_ctx[tc->c_thread_index].timer_wheel,
792 tc->timers[timer_id], interval);
794 tc->timers[timer_id] =
795 tw_timer_start_16t_2w_512sl (&tcp_main.
796 wrk_ctx[tc->c_thread_index].timer_wheel,
797 tc->c_c_index, timer_id, interval);
801 tcp_retransmit_timer_set (tcp_connection_t * tc)
803 ASSERT (tc->snd_una != tc->snd_una_max);
804 tcp_timer_set (tc, TCP_TIMER_RETRANSMIT,
805 clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
809 tcp_retransmit_timer_reset (tcp_connection_t * tc)
811 tcp_timer_reset (tc, TCP_TIMER_RETRANSMIT);
815 tcp_retransmit_timer_force_update (tcp_connection_t * tc)
817 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT,
818 clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
822 tcp_persist_timer_set (tcp_connection_t * tc)
824 /* Reuse RTO. It's backed off in handler */
825 tcp_timer_set (tc, TCP_TIMER_PERSIST,
826 clib_max (tc->rto * TCP_TO_TIMER_TICK,
827 TCP_TIMER_PERSIST_MIN));
831 tcp_persist_timer_update (tcp_connection_t * tc)
833 tcp_timer_update (tc, TCP_TIMER_PERSIST,
834 clib_max (tc->rto * TCP_TO_TIMER_TICK,
835 TCP_TIMER_PERSIST_MIN));
839 tcp_persist_timer_reset (tcp_connection_t * tc)
841 tcp_timer_reset (tc, TCP_TIMER_PERSIST);
845 tcp_retransmit_timer_update (tcp_connection_t * tc)
847 if (tc->snd_una == tc->snd_una_max)
849 tcp_retransmit_timer_reset (tc);
850 if (tc->snd_wnd < tc->snd_mss)
851 tcp_persist_timer_update (tc);
854 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT,
855 clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
859 tcp_timer_is_active (tcp_connection_t * tc, tcp_timers_e timer)
861 return tc->timers[timer] != TCP_TIMER_HANDLE_INVALID;
864 #define tcp_validate_txf_size(_tc, _a) \
865 ASSERT(_tc->state != TCP_STATE_ESTABLISHED \
866 || session_tx_fifo_max_dequeue (&_tc->connection) >= _a)
868 void tcp_rcv_sacks (tcp_connection_t * tc, u32 ack);
869 u8 *tcp_scoreboard_replay (u8 * s, tcp_connection_t * tc, u8 verbose);
871 void tcp_cc_algo_register (tcp_cc_algorithm_type_e type,
872 const tcp_cc_algorithm_t * vft);
874 tcp_cc_algorithm_t *tcp_cc_algo_get (tcp_cc_algorithm_type_e type);
877 * Push TCP header to buffer
879 * @param vm - vlib_main
880 * @param b - buffer to write the header to
881 * @param sp_net - source port net order
882 * @param dp_net - destination port net order
883 * @param seq - sequence number net order
884 * @param ack - ack number net order
885 * @param tcp_hdr_opts_len - header and options length in bytes
886 * @param flags - header flags
887 * @param wnd - window size
889 * @return - pointer to start of TCP header
892 vlib_buffer_push_tcp_net_order (vlib_buffer_t * b, u16 sp, u16 dp, u32 seq,
893 u32 ack, u8 tcp_hdr_opts_len, u8 flags,
898 th = vlib_buffer_push_uninit (b, tcp_hdr_opts_len);
902 th->seq_number = seq;
903 th->ack_number = ack;
904 th->data_offset_and_reserved = (tcp_hdr_opts_len >> 2) << 4;
908 th->urgent_pointer = 0;
913 * Push TCP header to buffer
915 * @param b - buffer to write the header to
916 * @param sp_net - source port net order
917 * @param dp_net - destination port net order
918 * @param seq - sequence number host order
919 * @param ack - ack number host order
920 * @param tcp_hdr_opts_len - header and options length in bytes
921 * @param flags - header flags
922 * @param wnd - window size
924 * @return - pointer to start of TCP header
927 vlib_buffer_push_tcp (vlib_buffer_t * b, u16 sp_net, u16 dp_net, u32 seq,
928 u32 ack, u8 tcp_hdr_opts_len, u8 flags, u16 wnd)
930 return vlib_buffer_push_tcp_net_order (b, sp_net, dp_net,
931 clib_host_to_net_u32 (seq),
932 clib_host_to_net_u32 (ack),
933 tcp_hdr_opts_len, flags,
934 clib_host_to_net_u16 (wnd));
937 #endif /* _vnet_tcp_h_ */
940 * fd.io coding-style-patch-verification: ON
943 * eval: (c-set-style "gnu")