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
33 #define TCP_CC_DATA_SZ 20
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")
79 typedef enum _tcp_timers
81 #define _(sym, str) TCP_TIMER_##sym,
87 typedef void (timer_expiration_handler) (u32 index);
89 extern timer_expiration_handler tcp_timer_delack_handler;
90 extern timer_expiration_handler tcp_timer_retransmit_handler;
91 extern timer_expiration_handler tcp_timer_persist_handler;
92 extern timer_expiration_handler tcp_timer_retransmit_syn_handler;
94 #define TCP_TIMER_HANDLE_INVALID ((u32) ~0)
96 /* Timer delays as multiples of 100ms */
97 #define TCP_TO_TIMER_TICK TCP_TICK*10 /* Period for converting from TCP
98 * ticks to timer units */
99 #define TCP_DELACK_TIME 1 /* 0.1s */
100 #define TCP_ESTABLISH_TIME 750 /* 75s */
101 #define TCP_SYN_RCVD_TIME 600 /* 60s */
102 #define TCP_2MSL_TIME 300 /* 30s */
103 #define TCP_CLOSEWAIT_TIME 20 /* 2s */
104 #define TCP_TIMEWAIT_TIME 100 /* 10s */
105 #define TCP_CLEANUP_TIME 10 /* 1s Time to wait before cleanup */
106 #define TCP_TIMER_PERSIST_MIN 2 /* 0.2s */
108 #define TCP_RTO_MAX 60 * THZ /* Min max RTO (60s) as per RFC6298 */
109 #define TCP_RTO_MIN 0.2 * THZ /* Min RTO (200ms) - lower than standard */
110 #define TCP_RTT_MAX 30 * THZ /* 30s (probably too much) */
111 #define TCP_RTO_SYN_RETRIES 3 /* SYN retries without doubling RTO */
112 #define TCP_RTO_INIT 1 * THZ /* Initial retransmit timer */
114 /** TCP connection flags */
115 #define foreach_tcp_connection_flag \
116 _(SNDACK, "Send ACK") \
117 _(FINSNT, "FIN sent") \
118 _(SENT_RCV_WND0, "Sent 0 rcv_wnd") \
119 _(RECOVERY, "Recovery") \
120 _(FAST_RECOVERY, "Fast Recovery") \
121 _(DCNT_PENDING, "Disconnect pending") \
122 _(HALF_OPEN_DONE, "Half-open completed") \
123 _(FINPNDG, "FIN pending") \
124 _(FRXT_PENDING, "Fast-retransmit pending") \
125 _(FRXT_FIRST, "Fast-retransmit first again") \
126 _(DEQ_PENDING, "Pending dequeue acked") \
128 typedef enum _tcp_connection_flag_bits
130 #define _(sym, str) TCP_CONN_##sym##_BIT,
131 foreach_tcp_connection_flag
134 } tcp_connection_flag_bits_e;
136 typedef enum _tcp_connection_flag
138 #define _(sym, str) TCP_CONN_##sym = 1 << TCP_CONN_##sym##_BIT,
139 foreach_tcp_connection_flag
142 } tcp_connection_flags_e;
144 /** TCP buffer flags */
145 #define foreach_tcp_buf_flag \
146 _ (ACK) /**< Sending ACK. */ \
147 _ (DUPACK) /**< Sending DUPACK. */ \
151 #define _(f) TCP_BUF_BIT_##f,
159 #define _(f) TCP_BUF_FLAG_##f = 1 << TCP_BUF_BIT_##f,
164 #define TCP_SCOREBOARD_TRACE (0)
165 #define TCP_MAX_SACK_BLOCKS 256 /**< Max number of SACK blocks stored */
166 #define TCP_INVALID_SACK_HOLE_INDEX ((u32)~0)
168 typedef struct _scoreboard_trace_elt
175 } scoreboard_trace_elt_t;
177 typedef struct _sack_scoreboard_hole
179 u32 next; /**< Index for next entry in linked list */
180 u32 prev; /**< Index for previous entry in linked list */
181 u32 start; /**< Start sequence number */
182 u32 end; /**< End sequence number */
183 u8 is_lost; /**< Mark hole as lost */
184 } sack_scoreboard_hole_t;
186 typedef struct _sack_scoreboard
188 sack_scoreboard_hole_t *holes; /**< Pool of holes */
189 u32 head; /**< Index of first entry */
190 u32 tail; /**< Index of last entry */
191 u32 sacked_bytes; /**< Number of bytes sacked in sb */
192 u32 last_sacked_bytes; /**< Number of bytes last sacked */
193 u32 last_bytes_delivered; /**< Number of sack bytes delivered */
194 u32 snd_una_adv; /**< Bytes to add to snd_una */
195 u32 high_sacked; /**< Highest byte sacked (fack) */
196 u32 high_rxt; /**< Highest retransmitted sequence */
197 u32 rescue_rxt; /**< Rescue sequence number */
198 u32 lost_bytes; /**< Bytes lost as per RFC6675 */
199 u32 cur_rxt_hole; /**< Retransmitting from this hole */
201 #if TCP_SCOREBOARD_TRACE
202 scoreboard_trace_elt_t *trace;
207 #if TCP_SCOREBOARD_TRACE
208 #define tcp_scoreboard_trace_add(_tc, _ack) \
210 static u64 _group = 0; \
211 sack_scoreboard_t *_sb = &_tc->sack_sb; \
212 sack_block_t *_sack, *_sacks; \
213 scoreboard_trace_elt_t *_elt; \
216 _sacks = _tc->rcv_opts.sacks; \
217 for (i = 0; i < vec_len (_sacks); i++) \
219 _sack = &_sacks[i]; \
220 vec_add2 (_sb->trace, _elt, 1); \
221 _elt->start = _sack->start; \
222 _elt->end = _sack->end; \
223 _elt->ack = _elt->end == _ack ? _ack : 0; \
224 _elt->snd_una_max = _elt->end == _ack ? _tc->snd_una_max : 0; \
225 _elt->group = _group; \
229 #define tcp_scoreboard_trace_add(_tc, _ack)
232 sack_scoreboard_hole_t *scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
233 sack_scoreboard_hole_t *
234 start, u8 have_sent_1_smss,
237 sack_scoreboard_hole_t *scoreboard_get_hole (sack_scoreboard_t * sb,
240 sack_scoreboard_hole_t *scoreboard_next_hole (sack_scoreboard_t * sb,
241 sack_scoreboard_hole_t * hole);
242 sack_scoreboard_hole_t *scoreboard_prev_hole (sack_scoreboard_t * sb,
243 sack_scoreboard_hole_t * hole);
244 sack_scoreboard_hole_t *scoreboard_first_hole (sack_scoreboard_t * sb);
245 sack_scoreboard_hole_t *scoreboard_last_hole (sack_scoreboard_t * sb);
246 void scoreboard_clear (sack_scoreboard_t * sb);
247 void scoreboard_init (sack_scoreboard_t * sb);
248 u8 *format_tcp_scoreboard (u8 * s, va_list * args);
250 typedef enum _tcp_cc_algorithm_type
254 } tcp_cc_algorithm_type_e;
256 typedef struct _tcp_cc_algorithm tcp_cc_algorithm_t;
258 typedef enum _tcp_cc_ack_t
265 typedef struct _tcp_connection
267 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
268 transport_connection_t connection; /**< Common transport data. First! */
270 u8 state; /**< TCP state as per tcp_state_t */
271 u16 flags; /**< Connection flags (see tcp_conn_flags_e) */
272 u32 timers[TCP_N_TIMERS]; /**< Timer handles into timer wheel */
276 /** Send sequence variables RFC793 */
277 u32 snd_una; /**< oldest unacknowledged sequence number */
278 u32 snd_una_max; /**< newest unacknowledged sequence number + 1*/
279 u32 snd_wnd; /**< send window */
280 u32 snd_wl1; /**< seq number used for last snd.wnd update */
281 u32 snd_wl2; /**< ack number used for last snd.wnd update */
282 u32 snd_nxt; /**< next seq number to be sent */
283 u16 snd_mss; /**< Effective send max seg (data) size */
285 /** Receive sequence variables RFC793 */
286 u32 rcv_nxt; /**< next sequence number expected */
287 u32 rcv_wnd; /**< receive window we expect */
289 u32 rcv_las; /**< rcv_nxt at last ack sent/rcv_wnd update */
290 u32 iss; /**< initial sent sequence */
291 u32 irs; /**< initial remote sequence */
294 u8 snd_opts_len; /**< Tx options len */
295 u8 rcv_wscale; /**< Window scale to advertise to peer */
296 u8 snd_wscale; /**< Window scale to use when sending */
297 u32 tsval_recent; /**< Last timestamp received */
298 u32 tsval_recent_age; /**< When last updated tstamp_recent*/
299 tcp_options_t snd_opts; /**< Tx options for connection */
300 tcp_options_t rcv_opts; /**< Rx options for connection */
302 sack_block_t *snd_sacks; /**< Vector of SACKs to send. XXX Fixed size? */
303 sack_scoreboard_t sack_sb; /**< SACK "scoreboard" that tracks holes */
305 u16 rcv_dupacks; /**< Number of DUPACKs received */
306 u8 pending_dupacks; /**< Number of DUPACKs to be sent */
308 /* Congestion control */
309 u32 cwnd; /**< Congestion window */
310 u32 cwnd_acc_bytes; /**< Bytes accumulated for cwnd increment */
311 u32 ssthresh; /**< Slow-start threshold */
312 u32 prev_ssthresh; /**< ssthresh before congestion */
313 u32 prev_cwnd; /**< ssthresh before congestion */
314 u32 bytes_acked; /**< Bytes acknowledged by current segment */
315 u32 burst_acked; /**< Bytes acknowledged in current burst */
316 u32 snd_rxt_bytes; /**< Retransmitted bytes */
317 u32 snd_rxt_ts; /**< Timestamp when first packet is retransmitted */
318 u32 tsecr_last_ack; /**< Timestamp echoed to us in last healthy ACK */
319 u32 snd_congestion; /**< snd_una_max when congestion is detected */
320 tcp_cc_algorithm_t *cc_algo; /**< Congestion control algorithm */
321 u8 cc_data[TCP_CC_DATA_SZ]; /**< Congestion control algo private data */
324 u32 rto; /**< Retransmission timeout */
325 u32 rto_boff; /**< Index for RTO backoff */
326 u32 srtt; /**< Smoothed RTT */
327 u32 rttvar; /**< Smoothed mean RTT difference. Approximates variance */
328 u32 rtt_seq; /**< Sequence number for tracked ACK */
329 f64 rtt_ts; /**< Timestamp for tracked ACK */
330 f64 mrtt_us; /**< High precision mrtt from tracked acks */
332 u16 mss; /**< Our max seg size that includes options */
333 u32 limited_transmit; /**< snd_nxt when limited transmit starts */
334 u32 last_fib_check; /**< Last time we checked fib route for peer */
335 u32 sw_if_index; /**< Interface for the connection */
336 u32 tx_fifo_size; /**< Tx fifo size. Used to constrain cwnd */
339 struct _tcp_cc_algorithm
341 void (*rcv_ack) (tcp_connection_t * tc);
342 void (*rcv_cong_ack) (tcp_connection_t * tc, tcp_cc_ack_t ack);
343 void (*congestion) (tcp_connection_t * tc);
344 void (*recovered) (tcp_connection_t * tc);
345 void (*init) (tcp_connection_t * tc);
348 #define tcp_fastrecovery_on(tc) (tc)->flags |= TCP_CONN_FAST_RECOVERY
349 #define tcp_fastrecovery_off(tc) (tc)->flags &= ~TCP_CONN_FAST_RECOVERY
350 #define tcp_recovery_on(tc) (tc)->flags |= TCP_CONN_RECOVERY
351 #define tcp_recovery_off(tc) (tc)->flags &= ~TCP_CONN_RECOVERY
352 #define tcp_in_fastrecovery(tc) ((tc)->flags & TCP_CONN_FAST_RECOVERY)
353 #define tcp_in_recovery(tc) ((tc)->flags & (TCP_CONN_RECOVERY))
354 #define tcp_in_slowstart(tc) (tc->cwnd < tc->ssthresh)
355 #define tcp_disconnect_pending(tc) ((tc)->flags & TCP_CONN_DCNT_PENDING)
356 #define tcp_disconnect_pending_on(tc) ((tc)->flags |= TCP_CONN_DCNT_PENDING)
357 #define tcp_disconnect_pending_off(tc) ((tc)->flags &= ~TCP_CONN_DCNT_PENDING)
358 #define tcp_fastrecovery_first(tc) ((tc)->flags & TCP_CONN_FRXT_FIRST)
359 #define tcp_fastrecovery_first_on(tc) ((tc)->flags |= TCP_CONN_FRXT_FIRST)
360 #define tcp_fastrecovery_first_off(tc) ((tc)->flags &= ~TCP_CONN_FRXT_FIRST)
362 #define tcp_in_cong_recovery(tc) ((tc)->flags & \
363 (TCP_CONN_FAST_RECOVERY | TCP_CONN_RECOVERY))
366 tcp_cong_recovery_off (tcp_connection_t * tc)
368 tc->flags &= ~(TCP_CONN_FAST_RECOVERY | TCP_CONN_RECOVERY);
369 tcp_fastrecovery_first_off (tc);
372 typedef enum _tcp_error
374 #define tcp_error(n,s) TCP_ERROR_##n,
375 #include <vnet/tcp/tcp_error.def>
380 typedef struct _tcp_lookup_dispatch
383 } tcp_lookup_dispatch_t;
385 typedef struct tcp_worker_ctx_
387 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
391 /** worker timer wheel */
392 tw_timer_wheel_16t_2w_512sl_t timer_wheel;
394 /** tx buffer free list */
397 /** tx frames for tcp 4/6 output nodes */
398 vlib_frame_t *tx_frames[2];
400 /** tx frames for ip 4/6 lookup nodes */
401 vlib_frame_t *ip_lookup_tx_frames[2];
403 /** vector of connections needing fast rxt */
404 u32 *pending_fast_rxt;
406 /** vector of connections now doing fast rxt */
407 u32 *ongoing_fast_rxt;
409 /** vector of connections that will do fast rxt */
410 u32 *postponed_fast_rxt;
412 /** vector of pending ack dequeues */
413 u32 *pending_deq_acked;
415 /** vector of pending acks */
418 /** vector of pending disconnect notifications */
419 u32 *pending_disconnects;
421 /** convenience pointer to this thread's vlib main */
424 CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
426 /** cached 'on the wire' options for bursts */
431 typedef struct _tcp_main
433 /* Per-worker thread tcp connection pools */
434 tcp_connection_t **connections;
436 /* Pool of listeners. */
437 tcp_connection_t *listener_pool;
439 /** Dispatch table by state and flags */
440 tcp_lookup_dispatch_t dispatch_table[TCP_N_STATES][64];
442 u8 log2_tstamp_clocks_per_tick;
443 f64 tstamp_ticks_per_clock;
445 /** per-worker context */
446 tcp_worker_ctx_t *wrk_ctx;
448 /* Pool of half-open connections on which we've sent a SYN */
449 tcp_connection_t *half_open_connections;
450 clib_spinlock_t half_open_lock;
452 /* Congestion control algorithms registered */
453 tcp_cc_algorithm_t *cc_algos;
455 /** vlib buffer size */
456 u32 bytes_per_buffer;
462 /* Flag that indicates if stack is on or off */
465 /** Max rx fifo size for a session. It is used in to compute the
466 * rfc 7323 window scaling factor */
469 /** Number of preallocated connections */
470 u32 preallocated_connections;
471 u32 preallocated_half_open_connections;
473 /** Vectors of src addresses. Optional unless one needs > 63K active-opens */
474 ip4_address_t *ip4_src_addresses;
475 u32 last_v4_address_rotor;
476 u32 last_v6_address_rotor;
477 ip6_address_t *ip6_src_addresses;
479 /** Enable tx pacing for new connections */
485 /** fault-injection */
486 f64 buffer_fail_fraction;
491 extern tcp_main_t tcp_main;
492 extern vlib_node_registration_t tcp4_input_node;
493 extern vlib_node_registration_t tcp6_input_node;
494 extern vlib_node_registration_t tcp4_output_node;
495 extern vlib_node_registration_t tcp6_output_node;
497 always_inline tcp_main_t *
503 always_inline tcp_worker_ctx_t *
504 tcp_get_worker (u32 thread_index)
506 return &tcp_main.wrk_ctx[thread_index];
509 always_inline tcp_header_t *
510 tcp_buffer_hdr (vlib_buffer_t * b)
512 ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
513 return (tcp_header_t *) (b->data + b->current_data
514 + vnet_buffer (b)->tcp.hdr_offset);
517 #if (VLIB_BUFFER_TRACE_TRAJECTORY)
518 #define tcp_trajectory_add_start(b, start) \
520 (*vlib_buffer_trace_trajectory_cb) (b, start); \
523 #define tcp_trajectory_add_start(b, start)
526 clib_error_t *vnet_tcp_enable_disable (vlib_main_t * vm, u8 is_en);
528 void tcp_punt_unknown (vlib_main_t * vm, u8 is_ip4, u8 is_add);
530 always_inline tcp_connection_t *
531 tcp_connection_get (u32 conn_index, u32 thread_index)
534 (pool_is_free_index (tcp_main.connections[thread_index], conn_index)))
536 return pool_elt_at_index (tcp_main.connections[thread_index], conn_index);
539 always_inline tcp_connection_t *
540 tcp_connection_get_if_valid (u32 conn_index, u32 thread_index)
542 if (tcp_main.connections[thread_index] == 0)
544 if (pool_is_free_index (tcp_main.connections[thread_index], conn_index))
546 return pool_elt_at_index (tcp_main.connections[thread_index], conn_index);
549 always_inline tcp_connection_t *
550 tcp_get_connection_from_transport (transport_connection_t * tconn)
552 return (tcp_connection_t *) tconn;
555 void tcp_connection_close (tcp_connection_t * tc);
556 void tcp_connection_cleanup (tcp_connection_t * tc);
557 void tcp_connection_del (tcp_connection_t * tc);
558 int tcp_half_open_connection_cleanup (tcp_connection_t * tc);
559 tcp_connection_t *tcp_connection_new (u8 thread_index);
560 void tcp_connection_reset (tcp_connection_t * tc);
561 int tcp_configure_v4_source_address_range (vlib_main_t * vm,
562 ip4_address_t * start,
563 ip4_address_t * end, u32 table_id);
564 int tcp_configure_v6_source_address_range (vlib_main_t * vm,
565 ip6_address_t * start,
566 ip6_address_t * end, u32 table_id);
567 void tcp_api_reference (void);
568 u8 *format_tcp_connection (u8 * s, va_list * args);
570 always_inline tcp_connection_t *
571 tcp_listener_get (u32 tli)
573 return pool_elt_at_index (tcp_main.listener_pool, tli);
576 always_inline tcp_connection_t *
577 tcp_half_open_connection_get (u32 conn_index)
579 tcp_connection_t *tc = 0;
580 clib_spinlock_lock_if_init (&tcp_main.half_open_lock);
581 if (!pool_is_free_index (tcp_main.half_open_connections, conn_index))
582 tc = pool_elt_at_index (tcp_main.half_open_connections, conn_index);
583 clib_spinlock_unlock_if_init (&tcp_main.half_open_lock);
587 void tcp_make_ack (tcp_connection_t * ts, vlib_buffer_t * b);
588 void tcp_make_fin (tcp_connection_t * tc, vlib_buffer_t * b);
589 void tcp_make_synack (tcp_connection_t * ts, vlib_buffer_t * b);
590 void tcp_send_reset_w_pkt (tcp_connection_t * tc, vlib_buffer_t * pkt,
592 void tcp_send_reset (tcp_connection_t * tc);
593 void tcp_send_syn (tcp_connection_t * tc);
594 void tcp_send_synack (tcp_connection_t * tc);
595 void tcp_send_fin (tcp_connection_t * tc);
596 void tcp_init_mss (tcp_connection_t * tc);
597 void tcp_update_burst_snd_vars (tcp_connection_t * tc);
598 void tcp_update_rto (tcp_connection_t * tc);
599 void tcp_flush_frame_to_output (tcp_worker_ctx_t * wrk, u8 is_ip4);
600 void tcp_flush_frames_to_output (tcp_worker_ctx_t * wrk);
601 void tcp_program_fastretransmit (tcp_worker_ctx_t * wrk,
602 tcp_connection_t * tc);
603 void tcp_do_fastretransmits (tcp_worker_ctx_t * wrk);
605 void tcp_program_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc);
606 void tcp_program_dupack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc);
607 void tcp_send_acks (tcp_worker_ctx_t * wrk);
610 tcp_end_seq (tcp_header_t * th, u32 len)
612 return th->seq_number + tcp_is_syn (th) + tcp_is_fin (th) + len;
615 /* Modulo arithmetic for TCP sequence numbers */
616 #define seq_lt(_s1, _s2) ((i32)((_s1)-(_s2)) < 0)
617 #define seq_leq(_s1, _s2) ((i32)((_s1)-(_s2)) <= 0)
618 #define seq_gt(_s1, _s2) ((i32)((_s1)-(_s2)) > 0)
619 #define seq_geq(_s1, _s2) ((i32)((_s1)-(_s2)) >= 0)
620 #define seq_max(_s1, _s2) (seq_gt((_s1), (_s2)) ? (_s1) : (_s2))
622 /* Modulo arithmetic for timestamps */
623 #define timestamp_lt(_t1, _t2) ((i32)((_t1)-(_t2)) < 0)
624 #define timestamp_leq(_t1, _t2) ((i32)((_t1)-(_t2)) <= 0)
627 * Our estimate of the number of bytes that have left the network
630 tcp_bytes_out (const tcp_connection_t * tc)
632 if (tcp_opts_sack_permitted (&tc->rcv_opts))
633 return tc->sack_sb.sacked_bytes + tc->sack_sb.lost_bytes;
635 return tc->rcv_dupacks * tc->snd_mss;
639 * Our estimate of the number of bytes in flight (pipe size)
642 tcp_flight_size (const tcp_connection_t * tc)
646 flight_size = (int) (tc->snd_una_max - tc->snd_una) - tcp_bytes_out (tc)
653 ("Negative: %u %u %u dupacks %u sacked bytes %u flags %d",
654 tc->snd_una_max - tc->snd_una, tcp_bytes_out (tc),
655 tc->snd_rxt_bytes, tc->rcv_dupacks, tc->sack_sb.sacked_bytes,
664 * Initial cwnd as per RFC5681
667 tcp_initial_cwnd (const tcp_connection_t * tc)
669 if (tc->snd_mss > 2190)
670 return 2 * tc->snd_mss;
671 else if (tc->snd_mss > 1095)
672 return 3 * tc->snd_mss;
674 return 4 * tc->snd_mss;
678 * Accumulate acked bytes for cwnd increase
680 * Once threshold bytes are accumulated, snd_mss bytes are added
684 tcp_cwnd_accumulate (tcp_connection_t * tc, u32 thresh, u32 bytes)
686 tc->cwnd_acc_bytes += bytes;
687 if (tc->cwnd_acc_bytes >= thresh)
689 u32 inc = tc->cwnd_acc_bytes / thresh;
690 tc->cwnd_acc_bytes -= inc * thresh;
691 tc->cwnd += inc * tc->snd_mss;
692 tc->cwnd = clib_min (tc->cwnd, tc->tx_fifo_size);
697 tcp_loss_wnd (const tcp_connection_t * tc)
703 tcp_available_snd_wnd (const tcp_connection_t * tc)
705 return clib_min (tc->cwnd, tc->snd_wnd);
709 tcp_available_output_snd_space (const tcp_connection_t * tc)
711 u32 available_wnd = tcp_available_snd_wnd (tc);
712 int flight_size = (int) (tc->snd_nxt - tc->snd_una);
714 if (available_wnd <= flight_size)
717 return available_wnd - flight_size;
721 * Estimate of how many bytes we can still push into the network
724 tcp_available_cc_snd_space (const tcp_connection_t * tc)
726 u32 available_wnd = tcp_available_snd_wnd (tc);
727 u32 flight_size = tcp_flight_size (tc);
729 if (available_wnd <= flight_size)
732 return available_wnd - flight_size;
736 tcp_is_lost_fin (tcp_connection_t * tc)
738 if ((tc->flags & TCP_CONN_FINSNT) && tc->snd_una_max - tc->snd_una == 1)
743 u32 tcp_snd_space (tcp_connection_t * tc);
744 int tcp_retransmit_first_unacked (tcp_worker_ctx_t * wrk,
745 tcp_connection_t * tc);
746 int tcp_fast_retransmit_no_sack (tcp_worker_ctx_t * wrk,
747 tcp_connection_t * tc, u32 burst_size);
748 int tcp_fast_retransmit_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
750 int tcp_fast_retransmit (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
752 void tcp_cc_init_congestion (tcp_connection_t * tc);
753 void tcp_cc_fastrecovery_exit (tcp_connection_t * tc);
755 fib_node_index_t tcp_lookup_rmt_in_fib (tcp_connection_t * tc);
757 /* Made public for unit testing only */
758 void tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end);
759 u32 tcp_sack_list_bytes (tcp_connection_t * tc);
764 return tcp_main.wrk_ctx[vlib_get_thread_index ()].time_now;
768 tcp_time_now_w_thread (u32 thread_index)
770 return tcp_main.wrk_ctx[thread_index].time_now;
774 tcp_time_now_us (u32 thread_index)
776 return transport_time_now (thread_index);
780 tcp_set_time_now (tcp_worker_ctx_t * wrk)
782 wrk->time_now = clib_cpu_time_now () * tcp_main.tstamp_ticks_per_clock;
783 return wrk->time_now;
786 u32 tcp_push_header (tcp_connection_t * tconn, vlib_buffer_t * b);
788 void tcp_connection_timers_init (tcp_connection_t * tc);
789 void tcp_connection_timers_reset (tcp_connection_t * tc);
790 void tcp_init_snd_vars (tcp_connection_t * tc);
791 void tcp_connection_init_vars (tcp_connection_t * tc);
792 void tcp_connection_tx_pacer_update (tcp_connection_t * tc);
793 void tcp_connection_tx_pacer_reset (tcp_connection_t * tc, u32 window,
797 tcp_cc_rcv_ack (tcp_connection_t * tc)
799 tc->cc_algo->rcv_ack (tc);
800 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
804 tcp_timer_set (tcp_connection_t * tc, u8 timer_id, u32 interval)
806 ASSERT (tc->c_thread_index == vlib_get_thread_index ());
807 ASSERT (tc->timers[timer_id] == TCP_TIMER_HANDLE_INVALID);
808 tc->timers[timer_id] =
809 tw_timer_start_16t_2w_512sl (&tcp_main.
810 wrk_ctx[tc->c_thread_index].timer_wheel,
811 tc->c_c_index, timer_id, interval);
815 tcp_timer_reset (tcp_connection_t * tc, u8 timer_id)
817 ASSERT (tc->c_thread_index == vlib_get_thread_index ());
818 if (tc->timers[timer_id] == TCP_TIMER_HANDLE_INVALID)
821 tw_timer_stop_16t_2w_512sl (&tcp_main.
822 wrk_ctx[tc->c_thread_index].timer_wheel,
823 tc->timers[timer_id]);
824 tc->timers[timer_id] = TCP_TIMER_HANDLE_INVALID;
828 tcp_timer_update (tcp_connection_t * tc, u8 timer_id, u32 interval)
830 ASSERT (tc->c_thread_index == vlib_get_thread_index ());
831 if (tc->timers[timer_id] != TCP_TIMER_HANDLE_INVALID)
832 tw_timer_update_16t_2w_512sl (&tcp_main.
833 wrk_ctx[tc->c_thread_index].timer_wheel,
834 tc->timers[timer_id], interval);
836 tc->timers[timer_id] =
837 tw_timer_start_16t_2w_512sl (&tcp_main.
838 wrk_ctx[tc->c_thread_index].timer_wheel,
839 tc->c_c_index, timer_id, interval);
843 tcp_retransmit_timer_set (tcp_connection_t * tc)
845 ASSERT (tc->snd_una != tc->snd_una_max);
846 tcp_timer_set (tc, TCP_TIMER_RETRANSMIT,
847 clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
851 tcp_retransmit_timer_reset (tcp_connection_t * tc)
853 tcp_timer_reset (tc, TCP_TIMER_RETRANSMIT);
857 tcp_retransmit_timer_force_update (tcp_connection_t * tc)
859 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT,
860 clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
864 tcp_persist_timer_set (tcp_connection_t * tc)
866 /* Reuse RTO. It's backed off in handler */
867 tcp_timer_set (tc, TCP_TIMER_PERSIST,
868 clib_max (tc->rto * TCP_TO_TIMER_TICK,
869 TCP_TIMER_PERSIST_MIN));
873 tcp_persist_timer_update (tcp_connection_t * tc)
875 tcp_timer_update (tc, TCP_TIMER_PERSIST,
876 clib_max (tc->rto * TCP_TO_TIMER_TICK,
877 TCP_TIMER_PERSIST_MIN));
881 tcp_persist_timer_reset (tcp_connection_t * tc)
883 tcp_timer_reset (tc, TCP_TIMER_PERSIST);
887 tcp_retransmit_timer_update (tcp_connection_t * tc)
889 if (tc->snd_una == tc->snd_una_max)
891 tcp_retransmit_timer_reset (tc);
892 if (tc->snd_wnd < tc->snd_mss)
893 tcp_persist_timer_update (tc);
896 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT,
897 clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
901 tcp_timer_is_active (tcp_connection_t * tc, tcp_timers_e timer)
903 return tc->timers[timer] != TCP_TIMER_HANDLE_INVALID;
906 #define tcp_validate_txf_size(_tc, _a) \
907 ASSERT(_tc->state != TCP_STATE_ESTABLISHED \
908 || session_tx_fifo_max_dequeue (&_tc->connection) >= _a)
910 void tcp_rcv_sacks (tcp_connection_t * tc, u32 ack);
911 u8 *tcp_scoreboard_replay (u8 * s, tcp_connection_t * tc, u8 verbose);
913 void tcp_cc_algo_register (tcp_cc_algorithm_type_e type,
914 const tcp_cc_algorithm_t * vft);
916 tcp_cc_algorithm_t *tcp_cc_algo_get (tcp_cc_algorithm_type_e type);
919 tcp_cc_data (tcp_connection_t * tc)
921 return (void *) tc->cc_data;
924 void newreno_rcv_cong_ack (tcp_connection_t * tc, tcp_cc_ack_t ack_type);
927 * Push TCP header to buffer
929 * @param vm - vlib_main
930 * @param b - buffer to write the header to
931 * @param sp_net - source port net order
932 * @param dp_net - destination port net order
933 * @param seq - sequence number net order
934 * @param ack - ack number net order
935 * @param tcp_hdr_opts_len - header and options length in bytes
936 * @param flags - header flags
937 * @param wnd - window size
939 * @return - pointer to start of TCP header
942 vlib_buffer_push_tcp_net_order (vlib_buffer_t * b, u16 sp, u16 dp, u32 seq,
943 u32 ack, u8 tcp_hdr_opts_len, u8 flags,
948 th = vlib_buffer_push_uninit (b, tcp_hdr_opts_len);
952 th->seq_number = seq;
953 th->ack_number = ack;
954 th->data_offset_and_reserved = (tcp_hdr_opts_len >> 2) << 4;
958 th->urgent_pointer = 0;
963 * Push TCP header to buffer
965 * @param b - buffer to write the header to
966 * @param sp_net - source port net order
967 * @param dp_net - destination port net order
968 * @param seq - sequence number host order
969 * @param ack - ack number host order
970 * @param tcp_hdr_opts_len - header and options length in bytes
971 * @param flags - header flags
972 * @param wnd - window size
974 * @return - pointer to start of TCP header
977 vlib_buffer_push_tcp (vlib_buffer_t * b, u16 sp_net, u16 dp_net, u32 seq,
978 u32 ack, u8 tcp_hdr_opts_len, u8 flags, u16 wnd)
980 return vlib_buffer_push_tcp_net_order (b, sp_net, dp_net,
981 clib_host_to_net_u32 (seq),
982 clib_host_to_net_u32 (ack),
983 tcp_hdr_opts_len, flags,
984 clib_host_to_net_u16 (wnd));
987 #endif /* _vnet_tcp_h_ */
990 * fd.io coding-style-patch-verification: ON
993 * eval: (c-set-style "gnu")