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
34 #define TCP_MAX_GSO_SZ 65536
35 #define TCP_RXT_MAX_BURST 10
37 #define TCP_DUPACK_THRESHOLD 3
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") \
74 _(WAITCLOSE, "WAIT CLOSE") \
75 _(RETRANSMIT_SYN, "RETRANSMIT SYN") \
77 typedef enum _tcp_timers
79 #define _(sym, str) TCP_TIMER_##sym,
85 typedef void (timer_expiration_handler) (u32 index);
87 extern timer_expiration_handler tcp_timer_delack_handler;
88 extern timer_expiration_handler tcp_timer_retransmit_handler;
89 extern timer_expiration_handler tcp_timer_persist_handler;
90 extern timer_expiration_handler tcp_timer_retransmit_syn_handler;
92 #define TCP_TIMER_HANDLE_INVALID ((u32) ~0)
94 #define TCP_TIMER_TICK 0.1 /**< Timer tick in seconds */
95 #define TCP_TO_TIMER_TICK TCP_TICK*10 /**< Factor for converting
96 ticks to timer ticks */
98 #define TCP_RTO_MAX 60 * THZ /* Min max RTO (60s) as per RFC6298 */
99 #define TCP_RTO_MIN 0.2 * THZ /* Min RTO (200ms) - lower than standard */
100 #define TCP_RTT_MAX 30 * THZ /* 30s (probably too much) */
101 #define TCP_RTO_SYN_RETRIES 3 /* SYN retries without doubling RTO */
102 #define TCP_RTO_INIT 1 * THZ /* Initial retransmit timer */
103 #define TCP_RTO_BOFF_MAX 8 /* Max number of retries before reset */
104 #define TCP_ESTABLISH_TIME (60 * THZ) /* Connection establish timeout */
106 /** Connection configuration flags */
107 #define foreach_tcp_cfg_flag \
108 _(RATE_SAMPLE, "Rate sampling") \
109 _(NO_CSUM_OFFLOAD, "No csum offload") \
110 _(NO_TSO, "TSO off") \
113 typedef enum tcp_cfg_flag_bits_
115 #define _(sym, str) TCP_CFG_F_##sym##_BIT,
119 } tcp_cfg_flag_bits_e;
121 typedef enum tcp_cfg_flag_
123 #define _(sym, str) TCP_CFG_F_##sym = 1 << TCP_CFG_F_##sym##_BIT,
129 /** TCP connection flags */
130 #define foreach_tcp_connection_flag \
131 _(SNDACK, "Send ACK") \
132 _(FINSNT, "FIN sent") \
133 _(RECOVERY, "Recovery") \
134 _(FAST_RECOVERY, "Fast Recovery") \
135 _(DCNT_PENDING, "Disconnect pending") \
136 _(HALF_OPEN_DONE, "Half-open completed") \
137 _(FINPNDG, "FIN pending") \
138 _(RXT_PENDING, "Retransmit pending") \
139 _(FRXT_FIRST, "Retransmit first") \
140 _(DEQ_PENDING, "Dequeue pending ") \
141 _(PSH_PENDING, "PSH pending") \
142 _(FINRCVD, "FIN received") \
143 _(ZERO_RWND_SENT, "Zero RWND sent") \
145 typedef enum tcp_connection_flag_bits_
147 #define _(sym, str) TCP_CONN_##sym##_BIT,
148 foreach_tcp_connection_flag
151 } tcp_connection_flag_bits_e;
153 typedef enum tcp_connection_flag_
155 #define _(sym, str) TCP_CONN_##sym = 1 << TCP_CONN_##sym##_BIT,
156 foreach_tcp_connection_flag
159 } tcp_connection_flags_e;
161 #define TCP_SCOREBOARD_TRACE (0)
162 #define TCP_MAX_SACK_BLOCKS 256 /**< Max number of SACK blocks stored */
163 #define TCP_INVALID_SACK_HOLE_INDEX ((u32)~0)
165 typedef struct _scoreboard_trace_elt
172 } scoreboard_trace_elt_t;
174 typedef struct _sack_scoreboard_hole
176 u32 next; /**< Index for next entry in linked list */
177 u32 prev; /**< Index for previous entry in linked list */
178 u32 start; /**< Start sequence number */
179 u32 end; /**< End sequence number */
180 u8 is_lost; /**< Mark hole as lost */
181 } sack_scoreboard_hole_t;
183 typedef struct _sack_scoreboard
185 sack_scoreboard_hole_t *holes; /**< Pool of holes */
186 u32 head; /**< Index of first entry */
187 u32 tail; /**< Index of last entry */
188 u32 sacked_bytes; /**< Number of bytes sacked in sb */
189 u32 last_sacked_bytes; /**< Number of bytes last sacked */
190 u32 last_bytes_delivered; /**< Sack bytes delivered to app */
191 u32 rxt_sacked; /**< Rxt bytes last delivered */
192 u32 high_sacked; /**< Highest byte sacked (fack) */
193 u32 high_rxt; /**< Highest retransmitted sequence */
194 u32 rescue_rxt; /**< Rescue sequence number */
195 u32 lost_bytes; /**< Bytes lost as per RFC6675 */
196 u32 last_lost_bytes; /**< Number of bytes last lost */
197 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);
246 void scoreboard_clear (sack_scoreboard_t * sb);
247 void scoreboard_clear_reneging (sack_scoreboard_t * sb, u32 start, u32 end);
248 void scoreboard_init (sack_scoreboard_t * sb);
249 void scoreboard_init_rxt (sack_scoreboard_t * sb, u32 snd_una);
250 u8 *format_tcp_scoreboard (u8 * s, va_list * args);
252 #define TCP_BTS_INVALID_INDEX ((u32)~0)
254 typedef enum tcp_bts_flags_
257 TCP_BTS_IS_APP_LIMITED = 1 << 1,
258 TCP_BTS_IS_SACKED = 1 << 2,
259 TCP_BTS_IS_RXT_LOST = 1 << 3,
260 } __clib_packed tcp_bts_flags_t;
262 typedef struct tcp_bt_sample_
264 u32 next; /**< Next sample index in list */
265 u32 prev; /**< Previous sample index in list */
266 u32 min_seq; /**< Min seq number in sample */
267 u32 max_seq; /**< Max seq number. Set for rxt samples */
268 u64 delivered; /**< Total delivered bytes for sample */
269 f64 delivered_time; /**< Delivered time when sample taken */
270 f64 tx_time; /**< Transmit time for the burst */
271 f64 first_tx_time; /**< Connection first tx time at tx */
272 tcp_bts_flags_t flags; /**< Sample flag */
275 typedef struct tcp_rate_sample_
277 u64 prior_delivered; /**< Delivered of sample used for rate, i.e.,
278 total bytes delivered at prior_time */
279 f64 prior_time; /**< Delivered time of sample used for rate */
280 f64 interval_time; /**< Time to ack the bytes delivered */
281 f64 rtt_time; /**< RTT for sample */
282 u32 delivered; /**< Bytes delivered in interval_time */
283 u32 acked_and_sacked; /**< Bytes acked + sacked now */
284 u32 lost; /**< Bytes lost now */
285 tcp_bts_flags_t flags; /**< Rate sample flags from bt sample */
288 typedef struct tcp_byte_tracker_
290 tcp_bt_sample_t *samples; /**< Pool of samples */
291 rb_tree_t sample_lookup; /**< Rbtree for sample lookup by min_seq */
292 u32 head; /**< Head of samples linked list */
293 u32 tail; /**< Tail of samples linked list */
294 u32 last_ooo; /**< Cached last ooo sample */
295 } tcp_byte_tracker_t;
297 typedef enum _tcp_cc_algorithm_type
301 TCP_CC_LAST = TCP_CC_CUBIC
302 } tcp_cc_algorithm_type_e;
304 typedef struct _tcp_cc_algorithm tcp_cc_algorithm_t;
306 typedef enum _tcp_cc_ack_t
313 typedef enum tcp_cc_event_
319 * As per RFC4898 tcpEStatsStackSoftErrors
321 typedef struct tcp_errors_
323 u32 below_data_wnd; /**< All data in seg is below snd_una */
324 u32 above_data_wnd; /**< Some data in segment is above snd_wnd */
325 u32 below_ack_wnd; /**< Acks for data below snd_una */
326 u32 above_ack_wnd; /**< Acks for data not sent */
329 typedef struct _tcp_connection
331 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
332 transport_connection_t connection; /**< Common transport data. First! */
334 u8 state; /**< TCP state as per tcp_state_t */
335 u8 cfg_flags; /**< Connection configuration flags */
336 u16 flags; /**< Connection flags (see tcp_conn_flags_e) */
337 u32 timers[TCP_N_TIMERS]; /**< Timer handles into timer wheel */
339 u64 segs_in; /** RFC4022/4898 tcpHCInSegs/tcpEStatsPerfSegsIn */
340 u64 bytes_in; /** RFC4898 tcpEStatsPerfHCDataOctetsIn */
341 u64 segs_out; /** RFC4898 tcpEStatsPerfSegsOut */
342 u64 bytes_out; /** RFC4898 tcpEStatsPerfHCDataOctetsOut */
344 /** Send sequence variables RFC793 */
345 u32 snd_una; /**< oldest unacknowledged sequence number */
346 u32 snd_una_max; /**< newest unacknowledged sequence number + 1*/
347 u32 snd_wnd; /**< send window */
348 u32 snd_wl1; /**< seq number used for last snd.wnd update */
349 u32 snd_wl2; /**< ack number used for last snd.wnd update */
350 u32 snd_nxt; /**< next seq number to be sent */
351 u16 snd_mss; /**< Effective send max seg (data) size */
353 u64 data_segs_in; /** RFC4898 tcpEStatsPerfDataSegsIn */
354 u64 data_segs_out; /** RFC4898 tcpEStatsPerfDataSegsOut */
356 /** Receive sequence variables RFC793 */
357 u32 rcv_nxt; /**< next sequence number expected */
358 u32 rcv_wnd; /**< receive window we expect */
360 u32 rcv_las; /**< rcv_nxt at last ack sent/rcv_wnd update */
361 u32 iss; /**< initial sent sequence */
362 u32 irs; /**< initial remote sequence */
365 u8 snd_opts_len; /**< Tx options len */
366 u8 rcv_wscale; /**< Window scale to advertise to peer */
367 u8 snd_wscale; /**< Window scale to use when sending */
368 u32 tsval_recent; /**< Last timestamp received */
369 u32 tsval_recent_age; /**< When last updated tstamp_recent*/
370 tcp_options_t snd_opts; /**< Tx options for connection */
371 tcp_options_t rcv_opts; /**< Rx options for connection */
373 sack_block_t *snd_sacks; /**< Vector of SACKs to send. XXX Fixed size? */
374 u8 snd_sack_pos; /**< Position in vec of first block to send */
375 sack_block_t *snd_sacks_fl; /**< Vector for building new list */
376 sack_scoreboard_t sack_sb; /**< SACK "scoreboard" that tracks holes */
378 u16 rcv_dupacks; /**< Number of recent DUPACKs received */
379 u32 dupacks_in; /**< RFC4898 tcpEStatsStackDupAcksIn*/
380 u8 pending_dupacks; /**< Number of DUPACKs to be sent */
381 u32 dupacks_out; /**< RFC4898 tcpEStatsPathDupAcksOut */
383 /* Congestion control */
384 u32 cwnd; /**< Congestion window */
385 u32 cwnd_acc_bytes; /**< Bytes accumulated for cwnd increment */
386 u32 ssthresh; /**< Slow-start threshold */
387 u32 prev_ssthresh; /**< ssthresh before congestion */
388 u32 prev_cwnd; /**< ssthresh before congestion */
389 u32 bytes_acked; /**< Bytes acknowledged by current segment */
390 u32 burst_acked; /**< Bytes acknowledged in current burst */
391 u32 snd_rxt_bytes; /**< Retransmitted bytes during current cc event */
392 u32 snd_rxt_ts; /**< Timestamp when first packet is retransmitted */
393 u32 prr_delivered; /**< RFC6937 bytes delivered during current event */
394 u32 prr_start; /**< snd_una when prr starts */
395 u32 rxt_delivered; /**< Rxt bytes delivered during current cc event */
396 u32 rxt_head; /**< snd_una last time we re rxted the head */
397 u32 prev_dsegs_out; /**< Number of dsegs after last ack */
398 u32 tsecr_last_ack; /**< Timestamp echoed to us in last healthy ACK */
399 u32 snd_congestion; /**< snd_una_max when congestion is detected */
400 u32 tx_fifo_size; /**< Tx fifo size. Used to constrain cwnd */
401 tcp_cc_algorithm_t *cc_algo; /**< Congestion control algorithm */
402 u8 cc_data[TCP_CC_DATA_SZ]; /**< Congestion control algo private data */
404 u32 fr_occurences; /**< fast-retransmit occurrences RFC4898
405 tcpEStatsStackFastRetran */
406 u32 tr_occurences; /**< timer-retransmit occurrences */
407 u64 bytes_retrans; /**< RFC4898 tcpEStatsPerfOctetsRetrans */
408 u64 segs_retrans; /**< RFC4898 tcpEStatsPerfSegsRetrans*/
411 u32 rto; /**< Retransmission timeout */
412 u32 rto_boff; /**< Index for RTO backoff */
413 u32 srtt; /**< Smoothed RTT */
414 u32 rttvar; /**< Smoothed mean RTT difference. Approximates variance */
415 u32 rtt_seq; /**< Sequence number for tracked ACK */
416 f64 rtt_ts; /**< Timestamp for tracked ACK */
417 f64 mrtt_us; /**< High precision mrtt from tracked acks */
419 u32 psh_seq; /**< Add psh header for seg that includes this */
420 u32 next_node_index; /**< Can be used to control next node in output */
421 u32 next_node_opaque; /**< Opaque to pass to next node */
422 u32 limited_transmit; /**< snd_nxt when limited transmit starts */
423 u32 sw_if_index; /**< Interface for the connection */
425 /* Delivery rate estimation */
426 u64 delivered; /**< Total bytes delivered to peer */
427 u64 app_limited; /**< Delivered when app-limited detected */
428 f64 delivered_time; /**< Time last bytes were acked */
429 f64 first_tx_time; /**< Send time for recently delivered/sent */
430 tcp_byte_tracker_t *bt; /**< Tx byte tracker */
432 tcp_errors_t errors; /**< Soft connection errors */
434 f64 start_ts; /**< Timestamp when connection initialized */
435 u32 last_fib_check; /**< Last time we checked fib route for peer */
436 u16 mss; /**< Our max seg size that includes options */
437 u32 timestamp_delta; /**< Offset for timestamp */
438 u32 ipv6_flow_label; /**< flow label for ipv6 header */
442 struct _tcp_cc_algorithm
445 uword (*unformat_cfg) (unformat_input_t * input);
446 void (*init) (tcp_connection_t * tc);
447 void (*cleanup) (tcp_connection_t * tc);
448 void (*rcv_ack) (tcp_connection_t * tc, tcp_rate_sample_t *rs);
449 void (*rcv_cong_ack) (tcp_connection_t * tc, tcp_cc_ack_t ack,
450 tcp_rate_sample_t *rs);
451 void (*congestion) (tcp_connection_t * tc);
452 void (*loss) (tcp_connection_t * tc);
453 void (*recovered) (tcp_connection_t * tc);
454 void (*undo_recovery) (tcp_connection_t * tc);
455 void (*event) (tcp_connection_t *tc, tcp_cc_event_t evt);
456 u64 (*get_pacing_rate) (tcp_connection_t *tc);
460 #define tcp_fastrecovery_on(tc) (tc)->flags |= TCP_CONN_FAST_RECOVERY
461 #define tcp_fastrecovery_off(tc) (tc)->flags &= ~TCP_CONN_FAST_RECOVERY
462 #define tcp_recovery_on(tc) (tc)->flags |= TCP_CONN_RECOVERY
463 #define tcp_recovery_off(tc) (tc)->flags &= ~TCP_CONN_RECOVERY
464 #define tcp_in_fastrecovery(tc) ((tc)->flags & TCP_CONN_FAST_RECOVERY)
465 #define tcp_in_recovery(tc) ((tc)->flags & (TCP_CONN_RECOVERY))
466 #define tcp_in_slowstart(tc) (tc->cwnd < tc->ssthresh)
467 #define tcp_disconnect_pending(tc) ((tc)->flags & TCP_CONN_DCNT_PENDING)
468 #define tcp_disconnect_pending_on(tc) ((tc)->flags |= TCP_CONN_DCNT_PENDING)
469 #define tcp_disconnect_pending_off(tc) ((tc)->flags &= ~TCP_CONN_DCNT_PENDING)
470 #define tcp_fastrecovery_first(tc) ((tc)->flags & TCP_CONN_FRXT_FIRST)
471 #define tcp_fastrecovery_first_on(tc) ((tc)->flags |= TCP_CONN_FRXT_FIRST)
472 #define tcp_fastrecovery_first_off(tc) ((tc)->flags &= ~TCP_CONN_FRXT_FIRST)
474 #define tcp_in_cong_recovery(tc) ((tc)->flags & \
475 (TCP_CONN_FAST_RECOVERY | TCP_CONN_RECOVERY))
477 #define tcp_csum_offload(tc) (!((tc)->cfg_flags & TCP_CFG_F_NO_CSUM_OFFLOAD))
480 tcp_cong_recovery_off (tcp_connection_t * tc)
482 tc->flags &= ~(TCP_CONN_FAST_RECOVERY | TCP_CONN_RECOVERY);
483 tcp_fastrecovery_first_off (tc);
486 #define tcp_zero_rwnd_sent(tc) ((tc)->flags & TCP_CONN_ZERO_RWND_SENT)
487 #define tcp_zero_rwnd_sent_on(tc) (tc)->flags |= TCP_CONN_ZERO_RWND_SENT
488 #define tcp_zero_rwnd_sent_off(tc) (tc)->flags &= ~TCP_CONN_ZERO_RWND_SENT
490 typedef enum _tcp_error
492 #define tcp_error(n,s) TCP_ERROR_##n,
493 #include <vnet/tcp/tcp_error.def>
498 typedef struct _tcp_lookup_dispatch
501 } tcp_lookup_dispatch_t;
503 typedef struct tcp_worker_ctx_
505 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
509 /** worker timer wheel */
510 tw_timer_wheel_16t_2w_512sl_t timer_wheel;
512 /** tx buffer free list */
515 /** tx frames for ip 4/6 lookup nodes */
516 vlib_frame_t *ip_lookup_tx_frames[2];
518 /** vector of pending ack dequeues */
519 u32 *pending_deq_acked;
521 /** vector of pending disconnect notifications */
522 u32 *pending_disconnects;
524 /** convenience pointer to this thread's vlib main */
527 CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
529 /** cached 'on the wire' options for bursts */
534 typedef struct tcp_iss_seed_
540 typedef struct tcp_configuration_
542 /** Max rx fifo size for a session (in bytes). It is used in to compute the
543 * rfc 7323 window scaling factor */
546 /** Min rx fifo for a session (in bytes) */
549 /** Default MTU to be used when establishing connections */
552 /** Initial CWND multiplier, which multiplies MSS to determine initial CWND.
553 * Set 0 to determine the initial CWND by another way */
554 u16 initial_cwnd_multiplier;
556 /** Enable tx pacing for new connections */
559 /** Allow use of TSO whenever available */
562 /** Default congestion control algorithm type */
563 tcp_cc_algorithm_type_e cc_algo;
565 /** Min rwnd, as number of snd_mss segments, for update ack to be sent after
566 * a zero rwnd advertisement */
567 u32 rwnd_min_update_ack;
569 /** Delayed ack time (disabled) */
572 /** Timer ticks to wait for close from app */
575 /** Timer ticks to wait in time-wait. Also known as 2MSL */
578 /** Timer ticks to wait in fin-wait1 to send fin and rcv fin-ack */
581 /** Timer ticks to wait in last ack for ack */
584 /** Timer ticks to wait in fin-wait2 for fin */
587 /** Timer ticks to wait in closing for fin ack */
590 /** Timer ticks to wait before cleaning up the connection */
593 /** Number of preallocated connections */
594 u32 preallocated_connections;
596 /** Number of preallocated half-open connections */
597 u32 preallocated_half_open_connections;
599 /** Vectors of src addresses. Optional unless one needs > 63K active-opens */
600 ip4_address_t *ip4_src_addrs;
601 ip6_address_t *ip6_src_addrs;
603 /** Fault-injection. Debug only */
604 f64 buffer_fail_fraction;
605 } tcp_configuration_t;
607 typedef struct _tcp_main
609 /* Per-worker thread tcp connection pools */
610 tcp_connection_t **connections;
612 /* Pool of listeners. */
613 tcp_connection_t *listener_pool;
615 /** Dispatch table by state and flags */
616 tcp_lookup_dispatch_t dispatch_table[TCP_N_STATES][64];
618 u8 log2_tstamp_clocks_per_tick;
619 f64 tstamp_ticks_per_clock;
621 /** per-worker context */
622 tcp_worker_ctx_t *wrk_ctx;
624 /** Pool of half-open connections on which we've sent a SYN */
625 tcp_connection_t *half_open_connections;
626 clib_spinlock_t half_open_lock;
628 /** vlib buffer size */
629 u32 bytes_per_buffer;
631 /** Seed used to generate random iss */
632 tcp_iss_seed_t iss_seed;
634 /** Congestion control algorithms registered */
635 tcp_cc_algorithm_t *cc_algos;
637 /** Hash table of cc algorithms by name */
638 uword *cc_algo_by_name;
640 /** Last cc algo registered */
641 tcp_cc_algorithm_type_e cc_last_type;
643 /** Flag that indicates if stack is on or off */
646 /** Flag that indicates if v4 punting is enabled */
649 /** Flag that indicates if v6 punting is enabled */
652 /** Rotor for v4 source addresses */
653 u32 last_v4_addr_rotor;
655 /** Rotor for v6 source addresses */
656 u32 last_v6_addr_rotor;
658 /** Protocol configuration */
659 tcp_configuration_t cfg;
662 extern tcp_main_t tcp_main;
663 extern vlib_node_registration_t tcp4_input_node;
664 extern vlib_node_registration_t tcp6_input_node;
665 extern vlib_node_registration_t tcp4_output_node;
666 extern vlib_node_registration_t tcp6_output_node;
667 extern vlib_node_registration_t tcp4_established_node;
668 extern vlib_node_registration_t tcp6_established_node;
669 extern vlib_node_registration_t tcp4_syn_sent_node;
670 extern vlib_node_registration_t tcp6_syn_sent_node;
671 extern vlib_node_registration_t tcp4_rcv_process_node;
672 extern vlib_node_registration_t tcp6_rcv_process_node;
673 extern vlib_node_registration_t tcp4_listen_node;
674 extern vlib_node_registration_t tcp6_listen_node;
676 #define tcp_cfg tcp_main.cfg
677 #define tcp_node_index(node_id, is_ip4) \
678 ((is_ip4) ? tcp4_##node_id##_node.index : tcp6_##node_id##_node.index)
680 always_inline tcp_main_t *
686 always_inline tcp_worker_ctx_t *
687 tcp_get_worker (u32 thread_index)
689 return &tcp_main.wrk_ctx[thread_index];
692 always_inline tcp_header_t *
693 tcp_buffer_hdr (vlib_buffer_t * b)
695 ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
696 return (tcp_header_t *) (b->data + b->current_data
697 + vnet_buffer (b)->tcp.hdr_offset);
700 #if (VLIB_BUFFER_TRACE_TRAJECTORY)
701 #define tcp_trajectory_add_start(b, start) \
703 (*vlib_buffer_trace_trajectory_cb) (b, start); \
706 #define tcp_trajectory_add_start(b, start)
709 clib_error_t *vnet_tcp_enable_disable (vlib_main_t * vm, u8 is_en);
711 void tcp_punt_unknown (vlib_main_t * vm, u8 is_ip4, u8 is_add);
713 always_inline tcp_connection_t *
714 tcp_connection_get (u32 conn_index, u32 thread_index)
717 (pool_is_free_index (tcp_main.connections[thread_index], conn_index)))
719 return pool_elt_at_index (tcp_main.connections[thread_index], conn_index);
722 always_inline tcp_connection_t *
723 tcp_connection_get_if_valid (u32 conn_index, u32 thread_index)
725 if (tcp_main.connections[thread_index] == 0)
727 if (pool_is_free_index (tcp_main.connections[thread_index], conn_index))
729 return pool_elt_at_index (tcp_main.connections[thread_index], conn_index);
732 always_inline tcp_connection_t *
733 tcp_get_connection_from_transport (transport_connection_t * tconn)
735 return (tcp_connection_t *) tconn;
739 tcp_connection_set_state (tcp_connection_t * tc, tcp_state_t state)
742 TCP_EVT (TCP_EVT_STATE_CHANGE, tc);
745 void tcp_connection_close (tcp_connection_t * tc);
746 void tcp_connection_cleanup (tcp_connection_t * tc);
747 void tcp_connection_del (tcp_connection_t * tc);
748 int tcp_half_open_connection_cleanup (tcp_connection_t * tc);
749 tcp_connection_t *tcp_connection_alloc (u8 thread_index);
750 tcp_connection_t *tcp_connection_alloc_w_base (u8 thread_index,
751 tcp_connection_t * base);
752 void tcp_connection_free (tcp_connection_t * tc);
753 void tcp_connection_reset (tcp_connection_t * tc);
754 int tcp_configure_v4_source_address_range (vlib_main_t * vm,
755 ip4_address_t * start,
756 ip4_address_t * end, u32 table_id);
757 int tcp_configure_v6_source_address_range (vlib_main_t * vm,
758 ip6_address_t * start,
759 ip6_address_t * end, u32 table_id);
760 void tcp_api_reference (void);
761 u8 *format_tcp_connection (u8 * s, va_list * args);
763 always_inline tcp_connection_t *
764 tcp_listener_get (u32 tli)
766 return pool_elt_at_index (tcp_main.listener_pool, tli);
769 always_inline tcp_connection_t *
770 tcp_half_open_connection_get (u32 conn_index)
772 tcp_connection_t *tc = 0;
773 clib_spinlock_lock_if_init (&tcp_main.half_open_lock);
774 if (!pool_is_free_index (tcp_main.half_open_connections, conn_index))
775 tc = pool_elt_at_index (tcp_main.half_open_connections, conn_index);
776 clib_spinlock_unlock_if_init (&tcp_main.half_open_lock);
780 void tcp_make_fin (tcp_connection_t * tc, vlib_buffer_t * b);
781 void tcp_make_synack (tcp_connection_t * ts, vlib_buffer_t * b);
782 void tcp_send_reset_w_pkt (tcp_connection_t * tc, vlib_buffer_t * pkt,
783 u32 thread_index, u8 is_ip4);
784 void tcp_send_reset (tcp_connection_t * tc);
785 void tcp_send_syn (tcp_connection_t * tc);
786 void tcp_send_synack (tcp_connection_t * tc);
787 void tcp_send_fin (tcp_connection_t * tc);
788 void tcp_send_ack (tcp_connection_t * tc);
789 void tcp_update_burst_snd_vars (tcp_connection_t * tc);
790 void tcp_update_rto (tcp_connection_t * tc);
791 void tcp_flush_frames_to_output (tcp_worker_ctx_t * wrk);
792 void tcp_send_window_update_ack (tcp_connection_t * tc);
794 void tcp_program_ack (tcp_connection_t * tc);
795 void tcp_program_dupack (tcp_connection_t * tc);
796 void tcp_program_retransmit (tcp_connection_t * tc);
803 * Byte tracker initialize
805 * @param tc connection for which the byte tracker should be allocated and
808 void tcp_bt_init (tcp_connection_t * tc);
810 * Byte tracker cleanup
812 * @param tc connection for which the byte tracker should be cleaned up
814 void tcp_bt_cleanup (tcp_connection_t * tc);
816 * Flush byte tracker samples
818 * @param tc tcp connection for which samples should be flushed
820 void tcp_bt_flush_samples (tcp_connection_t * tc);
822 * Track a tcp tx burst
824 * @param tc tcp connection
826 void tcp_bt_track_tx (tcp_connection_t * tc, u32 len);
828 * Track a tcp retransmission
830 * @param tc tcp connection
831 * @param start start sequence number
832 * @param end end sequence number
834 void tcp_bt_track_rxt (tcp_connection_t * tc, u32 start, u32 end);
836 * Generate a delivery rate sample from recently acked bytes
838 * @param tc tcp connection
839 * @param rs resulting rate sample
841 void tcp_bt_sample_delivery_rate (tcp_connection_t * tc,
842 tcp_rate_sample_t * rs);
844 * Check if sample to be generated is app limited
846 * @param tc tcp connection
848 void tcp_bt_check_app_limited (tcp_connection_t * tc);
850 * Check if the byte tracker is in sane state
852 * Should be used only for testing
854 * @param bt byte tracker
856 int tcp_bt_is_sane (tcp_byte_tracker_t * bt);
857 u8 *format_tcp_bt (u8 * s, va_list * args);
860 tcp_end_seq (tcp_header_t * th, u32 len)
862 return th->seq_number + tcp_is_syn (th) + tcp_is_fin (th) + len;
865 /* Modulo arithmetic for TCP sequence numbers */
866 #define seq_lt(_s1, _s2) ((i32)((_s1)-(_s2)) < 0)
867 #define seq_leq(_s1, _s2) ((i32)((_s1)-(_s2)) <= 0)
868 #define seq_gt(_s1, _s2) ((i32)((_s1)-(_s2)) > 0)
869 #define seq_geq(_s1, _s2) ((i32)((_s1)-(_s2)) >= 0)
870 #define seq_max(_s1, _s2) (seq_gt((_s1), (_s2)) ? (_s1) : (_s2))
872 /* Modulo arithmetic for timestamps */
873 #define timestamp_lt(_t1, _t2) ((i32)((_t1)-(_t2)) < 0)
874 #define timestamp_leq(_t1, _t2) ((i32)((_t1)-(_t2)) <= 0)
877 * Our estimate of the number of bytes that have left the network
880 tcp_bytes_out (const tcp_connection_t * tc)
882 if (tcp_opts_sack_permitted (&tc->rcv_opts))
883 return tc->sack_sb.sacked_bytes + tc->sack_sb.lost_bytes;
885 return tc->rcv_dupacks * tc->snd_mss;
889 * Our estimate of the number of bytes in flight (pipe size)
892 tcp_flight_size (const tcp_connection_t * tc)
896 flight_size = (int) (tc->snd_nxt - tc->snd_una) - tcp_bytes_out (tc)
897 + tc->snd_rxt_bytes - tc->rxt_delivered;
899 ASSERT (flight_size >= 0);
905 * Initial cwnd as per RFC5681
908 tcp_initial_cwnd (const tcp_connection_t * tc)
910 if (tcp_cfg.initial_cwnd_multiplier > 0)
911 return tcp_cfg.initial_cwnd_multiplier * tc->snd_mss;
913 if (tc->snd_mss > 2190)
914 return 2 * tc->snd_mss;
915 else if (tc->snd_mss > 1095)
916 return 3 * tc->snd_mss;
918 return 4 * tc->snd_mss;
922 * Accumulate acked bytes for cwnd increase
924 * Once threshold bytes are accumulated, snd_mss bytes are added
928 tcp_cwnd_accumulate (tcp_connection_t * tc, u32 thresh, u32 bytes)
930 tc->cwnd_acc_bytes += bytes;
931 if (tc->cwnd_acc_bytes >= thresh)
933 u32 inc = tc->cwnd_acc_bytes / thresh;
934 tc->cwnd_acc_bytes -= inc * thresh;
935 tc->cwnd += inc * tc->snd_mss;
936 tc->cwnd = clib_min (tc->cwnd, tc->tx_fifo_size);
941 tcp_loss_wnd (const tcp_connection_t * tc)
943 /* Whatever we have in flight + the packet we're about to send */
944 return tcp_flight_size (tc) + tc->snd_mss;
948 tcp_available_snd_wnd (const tcp_connection_t * tc)
950 return clib_min (tc->cwnd, tc->snd_wnd);
954 tcp_available_output_snd_space (const tcp_connection_t * tc)
956 u32 available_wnd = tcp_available_snd_wnd (tc);
957 int flight_size = (int) (tc->snd_nxt - tc->snd_una);
959 if (available_wnd <= flight_size)
962 return available_wnd - flight_size;
966 * Estimate of how many bytes we can still push into the network
969 tcp_available_cc_snd_space (const tcp_connection_t * tc)
971 u32 available_wnd = tcp_available_snd_wnd (tc);
972 u32 flight_size = tcp_flight_size (tc);
974 if (available_wnd <= flight_size)
977 return available_wnd - flight_size;
981 tcp_is_lost_fin (tcp_connection_t * tc)
983 if ((tc->flags & TCP_CONN_FINSNT) && (tc->snd_una_max - tc->snd_una == 1))
988 u32 tcp_snd_space (tcp_connection_t * tc);
989 int tcp_fastrecovery_prr_snd_space (tcp_connection_t * tc);
991 fib_node_index_t tcp_lookup_rmt_in_fib (tcp_connection_t * tc);
993 /* Made public for unit testing only */
994 void tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end);
995 u32 tcp_sack_list_bytes (tcp_connection_t * tc);
1000 return tcp_main.wrk_ctx[vlib_get_thread_index ()].time_now;
1004 tcp_time_now_w_thread (u32 thread_index)
1006 return tcp_main.wrk_ctx[thread_index].time_now;
1010 * Generate timestamp for tcp connection
1013 tcp_tstamp (tcp_connection_t * tc)
1015 return (tcp_main.wrk_ctx[tc->c_thread_index].time_now -
1016 tc->timestamp_delta);
1020 tcp_time_now_us (u32 thread_index)
1022 return transport_time_now (thread_index);
1026 tcp_set_time_now (tcp_worker_ctx_t * wrk)
1028 wrk->time_now = clib_cpu_time_now () * tcp_main.tstamp_ticks_per_clock;
1029 return wrk->time_now;
1032 u32 tcp_session_push_header (transport_connection_t * tconn,
1034 int tcp_session_custom_tx (void *conn, u32 max_burst_size);
1036 void tcp_connection_timers_init (tcp_connection_t * tc);
1037 void tcp_connection_timers_reset (tcp_connection_t * tc);
1038 void tcp_init_snd_vars (tcp_connection_t * tc);
1039 void tcp_connection_init_vars (tcp_connection_t * tc);
1040 void tcp_connection_tx_pacer_update (tcp_connection_t * tc);
1041 void tcp_connection_tx_pacer_reset (tcp_connection_t * tc, u32 window,
1045 tcp_cc_rcv_ack (tcp_connection_t * tc, tcp_rate_sample_t * rs)
1047 tc->cc_algo->rcv_ack (tc, rs);
1048 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1052 tcp_cc_rcv_cong_ack (tcp_connection_t * tc, tcp_cc_ack_t ack_type,
1053 tcp_rate_sample_t * rs)
1055 tc->cc_algo->rcv_cong_ack (tc, ack_type, rs);
1059 tcp_cc_congestion (tcp_connection_t * tc)
1061 tc->cc_algo->congestion (tc);
1065 tcp_cc_loss (tcp_connection_t * tc)
1067 tc->cc_algo->loss (tc);
1071 tcp_cc_recovered (tcp_connection_t * tc)
1073 tc->cc_algo->recovered (tc);
1077 tcp_cc_undo_recovery (tcp_connection_t * tc)
1079 if (tc->cc_algo->undo_recovery)
1080 tc->cc_algo->undo_recovery (tc);
1084 tcp_cc_event (tcp_connection_t * tc, tcp_cc_event_t evt)
1086 if (tc->cc_algo->event)
1087 tc->cc_algo->event (tc, evt);
1091 tcp_cc_get_pacing_rate (tcp_connection_t * tc)
1093 if (tc->cc_algo->get_pacing_rate)
1094 return tc->cc_algo->get_pacing_rate (tc);
1096 f64 srtt = clib_min ((f64) tc->srtt * TCP_TICK, tc->mrtt_us);
1098 /* TODO should constrain to interface's max throughput but
1099 * we don't have link speeds for sw ifs ..*/
1100 return ((f64) tc->cwnd / srtt);
1104 tcp_timer_set (tcp_connection_t * tc, u8 timer_id, u32 interval)
1106 ASSERT (tc->c_thread_index == vlib_get_thread_index ());
1107 ASSERT (tc->timers[timer_id] == TCP_TIMER_HANDLE_INVALID);
1108 tc->timers[timer_id] =
1109 tw_timer_start_16t_2w_512sl (&tcp_main.
1110 wrk_ctx[tc->c_thread_index].timer_wheel,
1111 tc->c_c_index, timer_id, interval);
1115 tcp_timer_reset (tcp_connection_t * tc, u8 timer_id)
1117 ASSERT (tc->c_thread_index == vlib_get_thread_index ());
1118 if (tc->timers[timer_id] == TCP_TIMER_HANDLE_INVALID)
1121 tw_timer_stop_16t_2w_512sl (&tcp_main.
1122 wrk_ctx[tc->c_thread_index].timer_wheel,
1123 tc->timers[timer_id]);
1124 tc->timers[timer_id] = TCP_TIMER_HANDLE_INVALID;
1128 tcp_timer_update (tcp_connection_t * tc, u8 timer_id, u32 interval)
1130 ASSERT (tc->c_thread_index == vlib_get_thread_index ());
1131 if (tc->timers[timer_id] != TCP_TIMER_HANDLE_INVALID)
1132 tw_timer_update_16t_2w_512sl (&tcp_main.
1133 wrk_ctx[tc->c_thread_index].timer_wheel,
1134 tc->timers[timer_id], interval);
1136 tc->timers[timer_id] =
1137 tw_timer_start_16t_2w_512sl (&tcp_main.
1138 wrk_ctx[tc->c_thread_index].timer_wheel,
1139 tc->c_c_index, timer_id, interval);
1143 tcp_retransmit_timer_set (tcp_connection_t * tc)
1145 ASSERT (tc->snd_una != tc->snd_una_max);
1146 tcp_timer_set (tc, TCP_TIMER_RETRANSMIT,
1147 clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
1151 tcp_retransmit_timer_reset (tcp_connection_t * tc)
1153 tcp_timer_reset (tc, TCP_TIMER_RETRANSMIT);
1157 tcp_retransmit_timer_force_update (tcp_connection_t * tc)
1159 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT,
1160 clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
1164 tcp_persist_timer_set (tcp_connection_t * tc)
1166 /* Reuse RTO. It's backed off in handler */
1167 tcp_timer_set (tc, TCP_TIMER_PERSIST,
1168 clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
1172 tcp_persist_timer_update (tcp_connection_t * tc)
1174 tcp_timer_update (tc, TCP_TIMER_PERSIST,
1175 clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
1179 tcp_persist_timer_reset (tcp_connection_t * tc)
1181 tcp_timer_reset (tc, TCP_TIMER_PERSIST);
1185 tcp_retransmit_timer_update (tcp_connection_t * tc)
1187 if (tc->snd_una == tc->snd_nxt)
1189 tcp_retransmit_timer_reset (tc);
1190 if (tc->snd_wnd < tc->snd_mss)
1191 tcp_persist_timer_update (tc);
1194 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT,
1195 clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
1199 tcp_timer_is_active (tcp_connection_t * tc, tcp_timers_e timer)
1201 return tc->timers[timer] != TCP_TIMER_HANDLE_INVALID;
1204 #define tcp_validate_txf_size(_tc, _a) \
1205 ASSERT(_tc->state != TCP_STATE_ESTABLISHED \
1206 || transport_max_tx_dequeue (&_tc->connection) >= _a)
1208 void tcp_rcv_sacks (tcp_connection_t * tc, u32 ack);
1209 u8 *tcp_scoreboard_replay (u8 * s, tcp_connection_t * tc, u8 verbose);
1212 * Register exiting cc algo type
1214 void tcp_cc_algo_register (tcp_cc_algorithm_type_e type,
1215 const tcp_cc_algorithm_t * vft);
1218 * Register new cc algo type
1220 tcp_cc_algorithm_type_e tcp_cc_algo_new_type (const tcp_cc_algorithm_t * vft);
1221 tcp_cc_algorithm_t *tcp_cc_algo_get (tcp_cc_algorithm_type_e type);
1223 static inline void *
1224 tcp_cc_data (tcp_connection_t * tc)
1226 return (void *) tc->cc_data;
1229 void newreno_rcv_cong_ack (tcp_connection_t * tc, tcp_cc_ack_t ack_type,
1230 tcp_rate_sample_t * rs);
1233 * Push TCP header to buffer
1235 * @param vm - vlib_main
1236 * @param b - buffer to write the header to
1237 * @param sp_net - source port net order
1238 * @param dp_net - destination port net order
1239 * @param seq - sequence number net order
1240 * @param ack - ack number net order
1241 * @param tcp_hdr_opts_len - header and options length in bytes
1242 * @param flags - header flags
1243 * @param wnd - window size
1245 * @return - pointer to start of TCP header
1247 always_inline void *
1248 vlib_buffer_push_tcp_net_order (vlib_buffer_t * b, u16 sp, u16 dp, u32 seq,
1249 u32 ack, u8 tcp_hdr_opts_len, u8 flags,
1254 th = vlib_buffer_push_uninit (b, tcp_hdr_opts_len);
1258 th->seq_number = seq;
1259 th->ack_number = ack;
1260 th->data_offset_and_reserved = (tcp_hdr_opts_len >> 2) << 4;
1264 th->urgent_pointer = 0;
1265 vnet_buffer (b)->l4_hdr_offset = (u8 *) th - b->data;
1266 b->flags |= VNET_BUFFER_F_L4_HDR_OFFSET_VALID;
1271 * Push TCP header to buffer
1273 * @param b - buffer to write the header to
1274 * @param sp_net - source port net order
1275 * @param dp_net - destination port net order
1276 * @param seq - sequence number host order
1277 * @param ack - ack number host order
1278 * @param tcp_hdr_opts_len - header and options length in bytes
1279 * @param flags - header flags
1280 * @param wnd - window size
1282 * @return - pointer to start of TCP header
1284 always_inline void *
1285 vlib_buffer_push_tcp (vlib_buffer_t * b, u16 sp_net, u16 dp_net, u32 seq,
1286 u32 ack, u8 tcp_hdr_opts_len, u8 flags, u16 wnd)
1288 return vlib_buffer_push_tcp_net_order (b, sp_net, dp_net,
1289 clib_host_to_net_u32 (seq),
1290 clib_host_to_net_u32 (ack),
1291 tcp_hdr_opts_len, flags,
1292 clib_host_to_net_u16 (wnd));
1295 #endif /* _vnet_tcp_h_ */
1298 * fd.io coding-style-patch-verification: ON
1301 * eval: (c-set-style "gnu")