2 * Copyright (c) 2016-2019 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
33 #define TCP_CC_DATA_SZ 24
35 #define TCP_DUPACK_THRESHOLD 3
36 #define TCP_MAX_RX_FIFO_SIZE 32 << 20
37 #define TCP_MIN_RX_FIFO_SIZE 4 << 10
38 #define TCP_IW_N_SEGMENTS 10
39 #define TCP_ALWAYS_ACK 1 /**< On/off delayed acks */
40 #define TCP_USE_SACKS 1 /**< Disable only for testing */
42 /** TCP FSM state definitions as per RFC793. */
43 #define foreach_tcp_fsm_state \
46 _(SYN_SENT, "SYN_SENT") \
47 _(SYN_RCVD, "SYN_RCVD") \
48 _(ESTABLISHED, "ESTABLISHED") \
49 _(CLOSE_WAIT, "CLOSE_WAIT") \
50 _(FIN_WAIT_1, "FIN_WAIT_1") \
51 _(LAST_ACK, "LAST_ACK") \
52 _(CLOSING, "CLOSING") \
53 _(FIN_WAIT_2, "FIN_WAIT_2") \
54 _(TIME_WAIT, "TIME_WAIT")
56 typedef enum _tcp_state
58 #define _(sym, str) TCP_STATE_##sym,
64 format_function_t format_tcp_state;
65 format_function_t format_tcp_flags;
66 format_function_t format_tcp_sacks;
67 format_function_t format_tcp_rcv_sacks;
70 #define foreach_tcp_timer \
71 _(RETRANSMIT, "RETRANSMIT") \
72 _(DELACK, "DELAYED ACK") \
73 _(PERSIST, "PERSIST") \
75 _(WAITCLOSE, "WAIT CLOSE") \
76 _(RETRANSMIT_SYN, "RETRANSMIT SYN") \
77 _(ESTABLISH, "ESTABLISH") \
78 _(ESTABLISH_AO, "ESTABLISH_AO") \
80 typedef enum _tcp_timers
82 #define _(sym, str) TCP_TIMER_##sym,
88 typedef void (timer_expiration_handler) (u32 index);
90 extern timer_expiration_handler tcp_timer_delack_handler;
91 extern timer_expiration_handler tcp_timer_retransmit_handler;
92 extern timer_expiration_handler tcp_timer_persist_handler;
93 extern timer_expiration_handler tcp_timer_retransmit_syn_handler;
95 #define TCP_TIMER_HANDLE_INVALID ((u32) ~0)
97 /* Timer delays as multiples of 100ms */
98 #define TCP_TO_TIMER_TICK TCP_TICK*10 /* Period for converting from TCP
99 * ticks to timer units */
100 #define TCP_DELACK_TIME 1 /* 0.1s */
101 #define TCP_ESTABLISH_TIME 750 /* 75s */
102 #define TCP_SYN_RCVD_TIME 600 /* 60s */
103 #define TCP_2MSL_TIME 300 /* 30s */
104 #define TCP_CLOSEWAIT_TIME 20 /* 2s */
105 #define TCP_TIMEWAIT_TIME 100 /* 10s */
106 #define TCP_FINWAIT1_TIME 600 /* 60s */
107 #define TCP_CLEANUP_TIME 1 /* 0.1s */
108 #define TCP_TIMER_PERSIST_MIN 2 /* 0.2s */
110 #define TCP_RTO_MAX 60 * THZ /* Min max RTO (60s) as per RFC6298 */
111 #define TCP_RTO_MIN 0.2 * THZ /* Min RTO (200ms) - lower than standard */
112 #define TCP_RTT_MAX 30 * THZ /* 30s (probably too much) */
113 #define TCP_RTO_SYN_RETRIES 3 /* SYN retries without doubling RTO */
114 #define TCP_RTO_INIT 1 * THZ /* Initial retransmit timer */
116 /** TCP connection flags */
117 #define foreach_tcp_connection_flag \
118 _(SNDACK, "Send ACK") \
119 _(FINSNT, "FIN sent") \
120 _(RECOVERY, "Recovery") \
121 _(FAST_RECOVERY, "Fast Recovery") \
122 _(DCNT_PENDING, "Disconnect pending") \
123 _(HALF_OPEN_DONE, "Half-open completed") \
124 _(FINPNDG, "FIN pending") \
125 _(FRXT_PENDING, "Fast-retransmit pending") \
126 _(FRXT_FIRST, "Fast-retransmit first again") \
127 _(DEQ_PENDING, "Pending dequeue acked") \
128 _(PSH_PENDING, "PSH pending") \
130 typedef enum _tcp_connection_flag_bits
132 #define _(sym, str) TCP_CONN_##sym##_BIT,
133 foreach_tcp_connection_flag
136 } tcp_connection_flag_bits_e;
138 typedef enum _tcp_connection_flag
140 #define _(sym, str) TCP_CONN_##sym = 1 << TCP_CONN_##sym##_BIT,
141 foreach_tcp_connection_flag
144 } tcp_connection_flags_e;
146 #define TCP_SCOREBOARD_TRACE (0)
147 #define TCP_MAX_SACK_BLOCKS 256 /**< Max number of SACK blocks stored */
148 #define TCP_INVALID_SACK_HOLE_INDEX ((u32)~0)
150 typedef struct _scoreboard_trace_elt
157 } scoreboard_trace_elt_t;
159 typedef struct _sack_scoreboard_hole
161 u32 next; /**< Index for next entry in linked list */
162 u32 prev; /**< Index for previous entry in linked list */
163 u32 start; /**< Start sequence number */
164 u32 end; /**< End sequence number */
165 u8 is_lost; /**< Mark hole as lost */
166 } sack_scoreboard_hole_t;
168 typedef struct _sack_scoreboard
170 sack_scoreboard_hole_t *holes; /**< Pool of holes */
171 u32 head; /**< Index of first entry */
172 u32 tail; /**< Index of last entry */
173 u32 sacked_bytes; /**< Number of bytes sacked in sb */
174 u32 last_sacked_bytes; /**< Number of bytes last sacked */
175 u32 last_bytes_delivered; /**< Number of sack bytes delivered */
176 u32 snd_una_adv; /**< Bytes to add to snd_una */
177 u32 high_sacked; /**< Highest byte sacked (fack) */
178 u32 high_rxt; /**< Highest retransmitted sequence */
179 u32 rescue_rxt; /**< Rescue sequence number */
180 u32 lost_bytes; /**< Bytes lost as per RFC6675 */
181 u32 cur_rxt_hole; /**< Retransmitting from this hole */
183 #if TCP_SCOREBOARD_TRACE
184 scoreboard_trace_elt_t *trace;
189 #if TCP_SCOREBOARD_TRACE
190 #define tcp_scoreboard_trace_add(_tc, _ack) \
192 static u64 _group = 0; \
193 sack_scoreboard_t *_sb = &_tc->sack_sb; \
194 sack_block_t *_sack, *_sacks; \
195 scoreboard_trace_elt_t *_elt; \
198 _sacks = _tc->rcv_opts.sacks; \
199 for (i = 0; i < vec_len (_sacks); i++) \
201 _sack = &_sacks[i]; \
202 vec_add2 (_sb->trace, _elt, 1); \
203 _elt->start = _sack->start; \
204 _elt->end = _sack->end; \
205 _elt->ack = _elt->end == _ack ? _ack : 0; \
206 _elt->snd_una_max = _elt->end == _ack ? _tc->snd_una_max : 0; \
207 _elt->group = _group; \
211 #define tcp_scoreboard_trace_add(_tc, _ack)
214 sack_scoreboard_hole_t *scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
215 sack_scoreboard_hole_t *
216 start, u8 have_sent_1_smss,
219 sack_scoreboard_hole_t *scoreboard_get_hole (sack_scoreboard_t * sb,
222 sack_scoreboard_hole_t *scoreboard_next_hole (sack_scoreboard_t * sb,
223 sack_scoreboard_hole_t * hole);
224 sack_scoreboard_hole_t *scoreboard_prev_hole (sack_scoreboard_t * sb,
225 sack_scoreboard_hole_t * hole);
226 sack_scoreboard_hole_t *scoreboard_first_hole (sack_scoreboard_t * sb);
227 sack_scoreboard_hole_t *scoreboard_last_hole (sack_scoreboard_t * sb);
228 void scoreboard_clear (sack_scoreboard_t * sb);
229 void scoreboard_init (sack_scoreboard_t * sb);
230 u8 *format_tcp_scoreboard (u8 * s, va_list * args);
232 typedef enum _tcp_cc_algorithm_type
236 } tcp_cc_algorithm_type_e;
238 typedef struct _tcp_cc_algorithm tcp_cc_algorithm_t;
240 typedef enum _tcp_cc_ack_t
247 typedef struct _tcp_connection
249 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
250 transport_connection_t connection; /**< Common transport data. First! */
252 u8 state; /**< TCP state as per tcp_state_t */
253 u16 flags; /**< Connection flags (see tcp_conn_flags_e) */
254 u32 timers[TCP_N_TIMERS]; /**< Timer handles into timer wheel */
258 /** Send sequence variables RFC793 */
259 u32 snd_una; /**< oldest unacknowledged sequence number */
260 u32 snd_una_max; /**< newest unacknowledged sequence number + 1*/
261 u32 snd_wnd; /**< send window */
262 u32 snd_wl1; /**< seq number used for last snd.wnd update */
263 u32 snd_wl2; /**< ack number used for last snd.wnd update */
264 u32 snd_nxt; /**< next seq number to be sent */
265 u16 snd_mss; /**< Effective send max seg (data) size */
267 /** Receive sequence variables RFC793 */
268 u32 rcv_nxt; /**< next sequence number expected */
269 u32 rcv_wnd; /**< receive window we expect */
271 u32 rcv_las; /**< rcv_nxt at last ack sent/rcv_wnd update */
272 u32 iss; /**< initial sent sequence */
273 u32 irs; /**< initial remote sequence */
276 u8 snd_opts_len; /**< Tx options len */
277 u8 rcv_wscale; /**< Window scale to advertise to peer */
278 u8 snd_wscale; /**< Window scale to use when sending */
279 u32 tsval_recent; /**< Last timestamp received */
280 u32 tsval_recent_age; /**< When last updated tstamp_recent*/
281 tcp_options_t snd_opts; /**< Tx options for connection */
282 tcp_options_t rcv_opts; /**< Rx options for connection */
284 sack_block_t *snd_sacks; /**< Vector of SACKs to send. XXX Fixed size? */
285 u8 snd_sack_pos; /**< Position in vec of first block to send */
286 sack_block_t *snd_sacks_fl; /**< Vector for building new list */
287 sack_scoreboard_t sack_sb; /**< SACK "scoreboard" that tracks holes */
289 u16 rcv_dupacks; /**< Number of DUPACKs received */
290 u8 pending_dupacks; /**< Number of DUPACKs to be sent */
292 /* Congestion control */
293 u32 cwnd; /**< Congestion window */
294 u32 cwnd_acc_bytes; /**< Bytes accumulated for cwnd increment */
295 u32 ssthresh; /**< Slow-start threshold */
296 u32 prev_ssthresh; /**< ssthresh before congestion */
297 u32 prev_cwnd; /**< ssthresh before congestion */
298 u32 bytes_acked; /**< Bytes acknowledged by current segment */
299 u32 burst_acked; /**< Bytes acknowledged in current burst */
300 u32 snd_rxt_bytes; /**< Retransmitted bytes */
301 u32 snd_rxt_ts; /**< Timestamp when first packet is retransmitted */
302 u32 tsecr_last_ack; /**< Timestamp echoed to us in last healthy ACK */
303 u32 snd_congestion; /**< snd_una_max when congestion is detected */
304 tcp_cc_algorithm_t *cc_algo; /**< Congestion control algorithm */
305 u8 cc_data[TCP_CC_DATA_SZ]; /**< Congestion control algo private data */
308 u32 rto; /**< Retransmission timeout */
309 u32 rto_boff; /**< Index for RTO backoff */
310 u32 srtt; /**< Smoothed RTT */
311 u32 rttvar; /**< Smoothed mean RTT difference. Approximates variance */
312 u32 rtt_seq; /**< Sequence number for tracked ACK */
313 f64 rtt_ts; /**< Timestamp for tracked ACK */
314 f64 mrtt_us; /**< High precision mrtt from tracked acks */
316 u16 mss; /**< Our max seg size that includes options */
317 u32 limited_transmit; /**< snd_nxt when limited transmit starts */
318 u32 last_fib_check; /**< Last time we checked fib route for peer */
319 u32 sw_if_index; /**< Interface for the connection */
320 u32 tx_fifo_size; /**< Tx fifo size. Used to constrain cwnd */
322 u32 psh_seq; /**< Add psh header for seg that includes this */
326 struct _tcp_cc_algorithm
329 uword (*unformat_cfg) (unformat_input_t * input);
330 void (*rcv_ack) (tcp_connection_t * tc);
331 void (*rcv_cong_ack) (tcp_connection_t * tc, tcp_cc_ack_t ack);
332 void (*congestion) (tcp_connection_t * tc);
333 void (*recovered) (tcp_connection_t * tc);
334 void (*init) (tcp_connection_t * tc);
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_disconnect_pending(tc) ((tc)->flags & TCP_CONN_DCNT_PENDING)
346 #define tcp_disconnect_pending_on(tc) ((tc)->flags |= TCP_CONN_DCNT_PENDING)
347 #define tcp_disconnect_pending_off(tc) ((tc)->flags &= ~TCP_CONN_DCNT_PENDING)
348 #define tcp_fastrecovery_first(tc) ((tc)->flags & TCP_CONN_FRXT_FIRST)
349 #define tcp_fastrecovery_first_on(tc) ((tc)->flags |= TCP_CONN_FRXT_FIRST)
350 #define tcp_fastrecovery_first_off(tc) ((tc)->flags &= ~TCP_CONN_FRXT_FIRST)
352 #define tcp_in_cong_recovery(tc) ((tc)->flags & \
353 (TCP_CONN_FAST_RECOVERY | TCP_CONN_RECOVERY))
356 tcp_cong_recovery_off (tcp_connection_t * tc)
358 tc->flags &= ~(TCP_CONN_FAST_RECOVERY | TCP_CONN_RECOVERY);
359 tcp_fastrecovery_first_off (tc);
362 typedef enum _tcp_error
364 #define tcp_error(n,s) TCP_ERROR_##n,
365 #include <vnet/tcp/tcp_error.def>
370 typedef struct _tcp_lookup_dispatch
373 } tcp_lookup_dispatch_t;
375 typedef struct tcp_worker_ctx_
377 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
381 /** worker timer wheel */
382 tw_timer_wheel_16t_2w_512sl_t timer_wheel;
384 /** tx buffer free list */
387 /** tx frames for tcp 4/6 output nodes */
388 vlib_frame_t *tx_frames[2];
390 /** tx frames for ip 4/6 lookup nodes */
391 vlib_frame_t *ip_lookup_tx_frames[2];
393 /** vector of connections needing fast rxt */
394 u32 *pending_fast_rxt;
396 /** vector of connections now doing fast rxt */
397 u32 *ongoing_fast_rxt;
399 /** vector of connections that will do fast rxt */
400 u32 *postponed_fast_rxt;
402 /** vector of pending ack dequeues */
403 u32 *pending_deq_acked;
405 /** vector of pending acks */
408 /** vector of pending disconnect notifications */
409 u32 *pending_disconnects;
411 /** convenience pointer to this thread's vlib main */
414 CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
416 /** cached 'on the wire' options for bursts */
421 typedef struct tcp_iss_seed_
427 typedef struct _tcp_main
429 /* Per-worker thread tcp connection pools */
430 tcp_connection_t **connections;
432 /* Pool of listeners. */
433 tcp_connection_t *listener_pool;
435 /** Dispatch table by state and flags */
436 tcp_lookup_dispatch_t dispatch_table[TCP_N_STATES][64];
438 u8 log2_tstamp_clocks_per_tick;
439 f64 tstamp_ticks_per_clock;
441 /** per-worker context */
442 tcp_worker_ctx_t *wrk_ctx;
444 /* Pool of half-open connections on which we've sent a SYN */
445 tcp_connection_t *half_open_connections;
446 clib_spinlock_t half_open_lock;
448 /* Congestion control algorithms registered */
449 tcp_cc_algorithm_t *cc_algos;
451 /** vlib buffer size */
452 u32 bytes_per_buffer;
454 /* Seed used to generate random iss */
455 tcp_iss_seed_t iss_seed;
457 /** Hash table of cc algorithms by name */
458 uword *cc_algo_by_name;
464 /* Flag that indicates if stack is on or off */
467 /** Max rx fifo size for a session. It is used in to compute the
468 * rfc 7323 window scaling factor */
471 /** Default MTU to be used when establishing connections */
474 /** Number of preallocated connections */
475 u32 preallocated_connections;
476 u32 preallocated_half_open_connections;
478 /** Vectors of src addresses. Optional unless one needs > 63K active-opens */
479 ip4_address_t *ip4_src_addresses;
480 u32 last_v4_address_rotor;
481 u32 last_v6_address_rotor;
482 ip6_address_t *ip6_src_addresses;
484 /** Enable tx pacing for new connections */
490 /** fault-injection */
491 f64 buffer_fail_fraction;
493 /** Default congestion control algorithm type */
494 tcp_cc_algorithm_type_e cc_algo;
498 extern tcp_main_t tcp_main;
499 extern vlib_node_registration_t tcp4_input_node;
500 extern vlib_node_registration_t tcp6_input_node;
501 extern vlib_node_registration_t tcp4_output_node;
502 extern vlib_node_registration_t tcp6_output_node;
503 extern vlib_node_registration_t tcp4_established_node;
504 extern vlib_node_registration_t tcp6_established_node;
505 extern vlib_node_registration_t tcp4_syn_sent_node;
506 extern vlib_node_registration_t tcp6_syn_sent_node;
507 extern vlib_node_registration_t tcp4_rcv_process_node;
508 extern vlib_node_registration_t tcp6_rcv_process_node;
509 extern vlib_node_registration_t tcp4_listen_node;
510 extern vlib_node_registration_t tcp6_listen_node;
512 always_inline tcp_main_t *
518 always_inline tcp_worker_ctx_t *
519 tcp_get_worker (u32 thread_index)
521 return &tcp_main.wrk_ctx[thread_index];
524 always_inline tcp_header_t *
525 tcp_buffer_hdr (vlib_buffer_t * b)
527 ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
528 return (tcp_header_t *) (b->data + b->current_data
529 + vnet_buffer (b)->tcp.hdr_offset);
532 #if (VLIB_BUFFER_TRACE_TRAJECTORY)
533 #define tcp_trajectory_add_start(b, start) \
535 (*vlib_buffer_trace_trajectory_cb) (b, start); \
538 #define tcp_trajectory_add_start(b, start)
541 clib_error_t *vnet_tcp_enable_disable (vlib_main_t * vm, u8 is_en);
543 void tcp_punt_unknown (vlib_main_t * vm, u8 is_ip4, u8 is_add);
545 always_inline tcp_connection_t *
546 tcp_connection_get (u32 conn_index, u32 thread_index)
549 (pool_is_free_index (tcp_main.connections[thread_index], conn_index)))
551 return pool_elt_at_index (tcp_main.connections[thread_index], conn_index);
554 always_inline tcp_connection_t *
555 tcp_connection_get_if_valid (u32 conn_index, u32 thread_index)
557 if (tcp_main.connections[thread_index] == 0)
559 if (pool_is_free_index (tcp_main.connections[thread_index], conn_index))
561 return pool_elt_at_index (tcp_main.connections[thread_index], conn_index);
564 always_inline tcp_connection_t *
565 tcp_get_connection_from_transport (transport_connection_t * tconn)
567 return (tcp_connection_t *) tconn;
571 tcp_connection_set_state (tcp_connection_t * tc, tcp_state_t state)
574 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc);
577 void tcp_connection_close (tcp_connection_t * tc);
578 void tcp_connection_cleanup (tcp_connection_t * tc);
579 void tcp_connection_del (tcp_connection_t * tc);
580 int tcp_half_open_connection_cleanup (tcp_connection_t * tc);
581 tcp_connection_t *tcp_connection_alloc (u8 thread_index);
582 void tcp_connection_free (tcp_connection_t * tc);
583 void tcp_connection_reset (tcp_connection_t * tc);
584 int tcp_configure_v4_source_address_range (vlib_main_t * vm,
585 ip4_address_t * start,
586 ip4_address_t * end, u32 table_id);
587 int tcp_configure_v6_source_address_range (vlib_main_t * vm,
588 ip6_address_t * start,
589 ip6_address_t * end, u32 table_id);
590 void tcp_api_reference (void);
591 u8 *format_tcp_connection (u8 * s, va_list * args);
593 always_inline tcp_connection_t *
594 tcp_listener_get (u32 tli)
596 return pool_elt_at_index (tcp_main.listener_pool, tli);
599 always_inline tcp_connection_t *
600 tcp_half_open_connection_get (u32 conn_index)
602 tcp_connection_t *tc = 0;
603 clib_spinlock_lock_if_init (&tcp_main.half_open_lock);
604 if (!pool_is_free_index (tcp_main.half_open_connections, conn_index))
605 tc = pool_elt_at_index (tcp_main.half_open_connections, conn_index);
606 clib_spinlock_unlock_if_init (&tcp_main.half_open_lock);
610 void tcp_make_fin (tcp_connection_t * tc, vlib_buffer_t * b);
611 void tcp_make_synack (tcp_connection_t * ts, vlib_buffer_t * b);
612 void tcp_send_reset_w_pkt (tcp_connection_t * tc, vlib_buffer_t * pkt,
613 u32 thread_index, u8 is_ip4);
614 void tcp_send_reset (tcp_connection_t * tc);
615 void tcp_send_syn (tcp_connection_t * tc);
616 void tcp_send_synack (tcp_connection_t * tc);
617 void tcp_send_fin (tcp_connection_t * tc);
618 void tcp_init_mss (tcp_connection_t * tc);
619 void tcp_update_burst_snd_vars (tcp_connection_t * tc);
620 void tcp_update_rto (tcp_connection_t * tc);
621 void tcp_flush_frame_to_output (tcp_worker_ctx_t * wrk, u8 is_ip4);
622 void tcp_flush_frames_to_output (tcp_worker_ctx_t * wrk);
623 void tcp_program_fastretransmit (tcp_worker_ctx_t * wrk,
624 tcp_connection_t * tc);
625 void tcp_do_fastretransmits (tcp_worker_ctx_t * wrk);
627 void tcp_program_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc);
628 void tcp_program_dupack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc);
629 void tcp_send_acks (tcp_worker_ctx_t * wrk);
632 tcp_end_seq (tcp_header_t * th, u32 len)
634 return th->seq_number + tcp_is_syn (th) + tcp_is_fin (th) + len;
637 /* Modulo arithmetic for TCP sequence numbers */
638 #define seq_lt(_s1, _s2) ((i32)((_s1)-(_s2)) < 0)
639 #define seq_leq(_s1, _s2) ((i32)((_s1)-(_s2)) <= 0)
640 #define seq_gt(_s1, _s2) ((i32)((_s1)-(_s2)) > 0)
641 #define seq_geq(_s1, _s2) ((i32)((_s1)-(_s2)) >= 0)
642 #define seq_max(_s1, _s2) (seq_gt((_s1), (_s2)) ? (_s1) : (_s2))
644 /* Modulo arithmetic for timestamps */
645 #define timestamp_lt(_t1, _t2) ((i32)((_t1)-(_t2)) < 0)
646 #define timestamp_leq(_t1, _t2) ((i32)((_t1)-(_t2)) <= 0)
649 * Our estimate of the number of bytes that have left the network
652 tcp_bytes_out (const tcp_connection_t * tc)
654 if (tcp_opts_sack_permitted (&tc->rcv_opts))
655 return tc->sack_sb.sacked_bytes + tc->sack_sb.lost_bytes;
657 return tc->rcv_dupacks * tc->snd_mss;
661 * Our estimate of the number of bytes in flight (pipe size)
664 tcp_flight_size (const tcp_connection_t * tc)
668 flight_size = (int) (tc->snd_nxt - tc->snd_una) - tcp_bytes_out (tc)
675 ("Negative: %u %u %u dupacks %u sacked bytes %u flags %d",
676 tc->snd_una_max - tc->snd_una, tcp_bytes_out (tc),
677 tc->snd_rxt_bytes, tc->rcv_dupacks, tc->sack_sb.sacked_bytes,
686 * Initial cwnd as per RFC5681
689 tcp_initial_cwnd (const tcp_connection_t * tc)
691 if (tc->snd_mss > 2190)
692 return 2 * tc->snd_mss;
693 else if (tc->snd_mss > 1095)
694 return 3 * tc->snd_mss;
696 return 4 * tc->snd_mss;
700 * Accumulate acked bytes for cwnd increase
702 * Once threshold bytes are accumulated, snd_mss bytes are added
706 tcp_cwnd_accumulate (tcp_connection_t * tc, u32 thresh, u32 bytes)
708 tc->cwnd_acc_bytes += bytes;
709 if (tc->cwnd_acc_bytes >= thresh)
711 u32 inc = tc->cwnd_acc_bytes / thresh;
712 tc->cwnd_acc_bytes -= inc * thresh;
713 tc->cwnd += inc * tc->snd_mss;
714 tc->cwnd = clib_min (tc->cwnd, tc->tx_fifo_size);
719 tcp_loss_wnd (const tcp_connection_t * tc)
725 tcp_available_snd_wnd (const tcp_connection_t * tc)
727 return clib_min (tc->cwnd, tc->snd_wnd);
731 tcp_available_output_snd_space (const tcp_connection_t * tc)
733 u32 available_wnd = tcp_available_snd_wnd (tc);
734 int flight_size = (int) (tc->snd_nxt - tc->snd_una);
736 if (available_wnd <= flight_size)
739 return available_wnd - flight_size;
743 * Estimate of how many bytes we can still push into the network
746 tcp_available_cc_snd_space (const tcp_connection_t * tc)
748 u32 available_wnd = tcp_available_snd_wnd (tc);
749 u32 flight_size = tcp_flight_size (tc);
751 if (available_wnd <= flight_size)
754 return available_wnd - flight_size;
758 tcp_is_lost_fin (tcp_connection_t * tc)
760 if ((tc->flags & TCP_CONN_FINSNT) && tc->snd_una_max - tc->snd_una == 1)
765 u32 tcp_snd_space (tcp_connection_t * tc);
766 int tcp_retransmit_first_unacked (tcp_worker_ctx_t * wrk,
767 tcp_connection_t * tc);
768 int tcp_fast_retransmit_no_sack (tcp_worker_ctx_t * wrk,
769 tcp_connection_t * tc, u32 burst_size);
770 int tcp_fast_retransmit_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
772 int tcp_fast_retransmit (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
774 void tcp_cc_init_congestion (tcp_connection_t * tc);
775 void tcp_cc_fastrecovery_exit (tcp_connection_t * tc);
777 fib_node_index_t tcp_lookup_rmt_in_fib (tcp_connection_t * tc);
779 /* Made public for unit testing only */
780 void tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end);
781 u32 tcp_sack_list_bytes (tcp_connection_t * tc);
786 return tcp_main.wrk_ctx[vlib_get_thread_index ()].time_now;
790 tcp_time_now_w_thread (u32 thread_index)
792 return tcp_main.wrk_ctx[thread_index].time_now;
796 tcp_time_now_us (u32 thread_index)
798 return transport_time_now (thread_index);
802 tcp_set_time_now (tcp_worker_ctx_t * wrk)
804 wrk->time_now = clib_cpu_time_now () * tcp_main.tstamp_ticks_per_clock;
805 return wrk->time_now;
808 u32 tcp_session_push_header (transport_connection_t * tconn,
811 void tcp_connection_timers_init (tcp_connection_t * tc);
812 void tcp_connection_timers_reset (tcp_connection_t * tc);
813 void tcp_init_snd_vars (tcp_connection_t * tc);
814 void tcp_connection_init_vars (tcp_connection_t * tc);
815 void tcp_connection_tx_pacer_update (tcp_connection_t * tc);
816 void tcp_connection_tx_pacer_reset (tcp_connection_t * tc, u32 window,
820 tcp_cc_rcv_ack (tcp_connection_t * tc)
822 tc->cc_algo->rcv_ack (tc);
823 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
827 tcp_timer_set (tcp_connection_t * tc, u8 timer_id, u32 interval)
829 ASSERT (tc->c_thread_index == vlib_get_thread_index ());
830 ASSERT (tc->timers[timer_id] == TCP_TIMER_HANDLE_INVALID);
831 tc->timers[timer_id] =
832 tw_timer_start_16t_2w_512sl (&tcp_main.
833 wrk_ctx[tc->c_thread_index].timer_wheel,
834 tc->c_c_index, timer_id, interval);
838 tcp_timer_reset (tcp_connection_t * tc, u8 timer_id)
840 ASSERT (tc->c_thread_index == vlib_get_thread_index ());
841 if (tc->timers[timer_id] == TCP_TIMER_HANDLE_INVALID)
844 tw_timer_stop_16t_2w_512sl (&tcp_main.
845 wrk_ctx[tc->c_thread_index].timer_wheel,
846 tc->timers[timer_id]);
847 tc->timers[timer_id] = TCP_TIMER_HANDLE_INVALID;
851 tcp_timer_update (tcp_connection_t * tc, u8 timer_id, u32 interval)
853 ASSERT (tc->c_thread_index == vlib_get_thread_index ());
854 if (tc->timers[timer_id] != TCP_TIMER_HANDLE_INVALID)
855 tw_timer_update_16t_2w_512sl (&tcp_main.
856 wrk_ctx[tc->c_thread_index].timer_wheel,
857 tc->timers[timer_id], interval);
859 tc->timers[timer_id] =
860 tw_timer_start_16t_2w_512sl (&tcp_main.
861 wrk_ctx[tc->c_thread_index].timer_wheel,
862 tc->c_c_index, timer_id, interval);
866 tcp_retransmit_timer_set (tcp_connection_t * tc)
868 ASSERT (tc->snd_una != tc->snd_una_max);
869 tcp_timer_set (tc, TCP_TIMER_RETRANSMIT,
870 clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
874 tcp_retransmit_timer_reset (tcp_connection_t * tc)
876 tcp_timer_reset (tc, TCP_TIMER_RETRANSMIT);
880 tcp_retransmit_timer_force_update (tcp_connection_t * tc)
882 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT,
883 clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
887 tcp_persist_timer_set (tcp_connection_t * tc)
889 /* Reuse RTO. It's backed off in handler */
890 tcp_timer_set (tc, TCP_TIMER_PERSIST,
891 clib_max (tc->rto * TCP_TO_TIMER_TICK,
892 TCP_TIMER_PERSIST_MIN));
896 tcp_persist_timer_update (tcp_connection_t * tc)
898 tcp_timer_update (tc, TCP_TIMER_PERSIST,
899 clib_max (tc->rto * TCP_TO_TIMER_TICK,
900 TCP_TIMER_PERSIST_MIN));
904 tcp_persist_timer_reset (tcp_connection_t * tc)
906 tcp_timer_reset (tc, TCP_TIMER_PERSIST);
910 tcp_retransmit_timer_update (tcp_connection_t * tc)
912 if (tc->snd_una == tc->snd_nxt)
914 tcp_retransmit_timer_reset (tc);
915 if (tc->snd_wnd < tc->snd_mss)
916 tcp_persist_timer_update (tc);
919 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT,
920 clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
924 tcp_timer_is_active (tcp_connection_t * tc, tcp_timers_e timer)
926 return tc->timers[timer] != TCP_TIMER_HANDLE_INVALID;
929 #define tcp_validate_txf_size(_tc, _a) \
930 ASSERT(_tc->state != TCP_STATE_ESTABLISHED \
931 || transport_max_tx_dequeue (&_tc->connection) >= _a)
933 void tcp_rcv_sacks (tcp_connection_t * tc, u32 ack);
934 u8 *tcp_scoreboard_replay (u8 * s, tcp_connection_t * tc, u8 verbose);
936 void tcp_cc_algo_register (tcp_cc_algorithm_type_e type,
937 const tcp_cc_algorithm_t * vft);
939 tcp_cc_algorithm_t *tcp_cc_algo_get (tcp_cc_algorithm_type_e type);
942 tcp_cc_data (tcp_connection_t * tc)
944 return (void *) tc->cc_data;
947 void newreno_rcv_cong_ack (tcp_connection_t * tc, tcp_cc_ack_t ack_type);
950 * Push TCP header to buffer
952 * @param vm - vlib_main
953 * @param b - buffer to write the header to
954 * @param sp_net - source port net order
955 * @param dp_net - destination port net order
956 * @param seq - sequence number net order
957 * @param ack - ack number net order
958 * @param tcp_hdr_opts_len - header and options length in bytes
959 * @param flags - header flags
960 * @param wnd - window size
962 * @return - pointer to start of TCP header
965 vlib_buffer_push_tcp_net_order (vlib_buffer_t * b, u16 sp, u16 dp, u32 seq,
966 u32 ack, u8 tcp_hdr_opts_len, u8 flags,
971 th = vlib_buffer_push_uninit (b, tcp_hdr_opts_len);
975 th->seq_number = seq;
976 th->ack_number = ack;
977 th->data_offset_and_reserved = (tcp_hdr_opts_len >> 2) << 4;
981 th->urgent_pointer = 0;
986 * Push TCP header to buffer
988 * @param b - buffer to write the header to
989 * @param sp_net - source port net order
990 * @param dp_net - destination port net order
991 * @param seq - sequence number host order
992 * @param ack - ack number host order
993 * @param tcp_hdr_opts_len - header and options length in bytes
994 * @param flags - header flags
995 * @param wnd - window size
997 * @return - pointer to start of TCP header
1000 vlib_buffer_push_tcp (vlib_buffer_t * b, u16 sp_net, u16 dp_net, u32 seq,
1001 u32 ack, u8 tcp_hdr_opts_len, u8 flags, u16 wnd)
1003 return vlib_buffer_push_tcp_net_order (b, sp_net, dp_net,
1004 clib_host_to_net_u32 (seq),
1005 clib_host_to_net_u32 (ack),
1006 tcp_hdr_opts_len, flags,
1007 clib_host_to_net_u16 (wnd));
1010 #endif /* _vnet_tcp_h_ */
1013 * fd.io coding-style-patch-verification: ON
1016 * eval: (c-set-style "gnu")