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 } __clib_packed tcp_bts_flags_t;
261 typedef struct tcp_bt_sample_
263 u32 next; /**< Next sample index in list */
264 u32 prev; /**< Previous sample index in list */
265 u32 min_seq; /**< Min seq number in sample */
266 u32 max_seq; /**< Max seq number. Set for rxt samples */
267 u64 delivered; /**< Total delivered bytes for sample */
268 f64 delivered_time; /**< Delivered time when sample taken */
269 f64 tx_time; /**< Transmit time for the burst */
270 f64 first_tx_time; /**< Connection first tx time at tx */
271 tcp_bts_flags_t flags; /**< Sample flag */
274 typedef struct tcp_rate_sample_
276 u64 prior_delivered; /**< Delivered of sample used for rate, i.e.,
277 total bytes delivered at prior_time */
278 f64 prior_time; /**< Delivered time of sample used for rate */
279 f64 interval_time; /**< Time to ack the bytes delivered */
280 f64 rtt_time; /**< RTT for sample */
281 u32 delivered; /**< Bytes delivered in interval_time */
282 u32 acked_and_sacked; /**< Bytes acked + sacked now */
283 u32 lost; /**< Bytes lost now */
284 tcp_bts_flags_t flags; /**< Rate sample flags from bt sample */
287 typedef struct tcp_byte_tracker_
289 tcp_bt_sample_t *samples; /**< Pool of samples */
290 rb_tree_t sample_lookup; /**< Rbtree for sample lookup by min_seq */
291 u32 head; /**< Head of samples linked list */
292 u32 tail; /**< Tail of samples linked list */
293 u32 last_ooo; /**< Cached last ooo sample */
294 } tcp_byte_tracker_t;
296 typedef enum _tcp_cc_algorithm_type
300 TCP_CC_LAST = TCP_CC_CUBIC
301 } tcp_cc_algorithm_type_e;
303 typedef struct _tcp_cc_algorithm tcp_cc_algorithm_t;
305 typedef enum _tcp_cc_ack_t
312 typedef enum tcp_cc_event_
318 * As per RFC4898 tcpEStatsStackSoftErrors
320 typedef struct tcp_errors_
322 u32 below_data_wnd; /**< All data in seg is below snd_una */
323 u32 above_data_wnd; /**< Some data in segment is above snd_wnd */
324 u32 below_ack_wnd; /**< Acks for data below snd_una */
325 u32 above_ack_wnd; /**< Acks for data not sent */
328 typedef struct _tcp_connection
330 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
331 transport_connection_t connection; /**< Common transport data. First! */
333 u8 state; /**< TCP state as per tcp_state_t */
334 u8 cfg_flags; /**< Connection configuration flags */
335 u16 flags; /**< Connection flags (see tcp_conn_flags_e) */
336 u32 timers[TCP_N_TIMERS]; /**< Timer handles into timer wheel */
338 u64 segs_in; /** RFC4022/4898 tcpHCInSegs/tcpEStatsPerfSegsIn */
339 u64 bytes_in; /** RFC4898 tcpEStatsPerfHCDataOctetsIn */
340 u64 segs_out; /** RFC4898 tcpEStatsPerfSegsOut */
341 u64 bytes_out; /** RFC4898 tcpEStatsPerfHCDataOctetsOut */
343 /** Send sequence variables RFC793 */
344 u32 snd_una; /**< oldest unacknowledged sequence number */
345 u32 snd_una_max; /**< newest unacknowledged sequence number + 1*/
346 u32 snd_wnd; /**< send window */
347 u32 snd_wl1; /**< seq number used for last snd.wnd update */
348 u32 snd_wl2; /**< ack number used for last snd.wnd update */
349 u32 snd_nxt; /**< next seq number to be sent */
350 u16 snd_mss; /**< Effective send max seg (data) size */
352 u64 data_segs_in; /** RFC4898 tcpEStatsPerfDataSegsIn */
353 u64 data_segs_out; /** RFC4898 tcpEStatsPerfDataSegsOut */
355 /** Receive sequence variables RFC793 */
356 u32 rcv_nxt; /**< next sequence number expected */
357 u32 rcv_wnd; /**< receive window we expect */
359 u32 rcv_las; /**< rcv_nxt at last ack sent/rcv_wnd update */
360 u32 iss; /**< initial sent sequence */
361 u32 irs; /**< initial remote sequence */
364 u8 snd_opts_len; /**< Tx options len */
365 u8 rcv_wscale; /**< Window scale to advertise to peer */
366 u8 snd_wscale; /**< Window scale to use when sending */
367 u32 tsval_recent; /**< Last timestamp received */
368 u32 tsval_recent_age; /**< When last updated tstamp_recent*/
369 tcp_options_t snd_opts; /**< Tx options for connection */
370 tcp_options_t rcv_opts; /**< Rx options for connection */
372 sack_block_t *snd_sacks; /**< Vector of SACKs to send. XXX Fixed size? */
373 u8 snd_sack_pos; /**< Position in vec of first block to send */
374 sack_block_t *snd_sacks_fl; /**< Vector for building new list */
375 sack_scoreboard_t sack_sb; /**< SACK "scoreboard" that tracks holes */
377 u16 rcv_dupacks; /**< Number of recent DUPACKs received */
378 u32 dupacks_in; /**< RFC4898 tcpEStatsStackDupAcksIn*/
379 u8 pending_dupacks; /**< Number of DUPACKs to be sent */
380 u32 dupacks_out; /**< RFC4898 tcpEStatsPathDupAcksOut */
382 /* Congestion control */
383 u32 cwnd; /**< Congestion window */
384 u32 cwnd_acc_bytes; /**< Bytes accumulated for cwnd increment */
385 u32 ssthresh; /**< Slow-start threshold */
386 u32 prev_ssthresh; /**< ssthresh before congestion */
387 u32 prev_cwnd; /**< ssthresh before congestion */
388 u32 bytes_acked; /**< Bytes acknowledged by current segment */
389 u32 burst_acked; /**< Bytes acknowledged in current burst */
390 u32 snd_rxt_bytes; /**< Retransmitted bytes during current cc event */
391 u32 snd_rxt_ts; /**< Timestamp when first packet is retransmitted */
392 u32 prr_delivered; /**< RFC6937 bytes delivered during current event */
393 u32 prr_start; /**< snd_una when prr starts */
394 u32 rxt_delivered; /**< Rxt bytes delivered during current cc event */
395 u32 rxt_head; /**< snd_una last time we re rxted the head */
396 u32 prev_dsegs_out; /**< Number of dsegs after last ack */
397 u32 tsecr_last_ack; /**< Timestamp echoed to us in last healthy ACK */
398 u32 snd_congestion; /**< snd_una_max when congestion is detected */
399 u32 tx_fifo_size; /**< Tx fifo size. Used to constrain cwnd */
400 tcp_cc_algorithm_t *cc_algo; /**< Congestion control algorithm */
401 u8 cc_data[TCP_CC_DATA_SZ]; /**< Congestion control algo private data */
403 u32 fr_occurences; /**< fast-retransmit occurrences RFC4898
404 tcpEStatsStackFastRetran */
405 u32 tr_occurences; /**< timer-retransmit occurrences */
406 u64 bytes_retrans; /**< RFC4898 tcpEStatsPerfOctetsRetrans */
407 u64 segs_retrans; /**< RFC4898 tcpEStatsPerfSegsRetrans*/
410 u32 rto; /**< Retransmission timeout */
411 u32 rto_boff; /**< Index for RTO backoff */
412 u32 srtt; /**< Smoothed RTT */
413 u32 rttvar; /**< Smoothed mean RTT difference. Approximates variance */
414 u32 rtt_seq; /**< Sequence number for tracked ACK */
415 f64 rtt_ts; /**< Timestamp for tracked ACK */
416 f64 mrtt_us; /**< High precision mrtt from tracked acks */
418 u32 psh_seq; /**< Add psh header for seg that includes this */
419 u32 next_node_index; /**< Can be used to control next node in output */
420 u32 next_node_opaque; /**< Opaque to pass to next node */
421 u32 limited_transmit; /**< snd_nxt when limited transmit starts */
422 u32 sw_if_index; /**< Interface for the connection */
424 /* Delivery rate estimation */
425 u64 delivered; /**< Total bytes delivered to peer */
426 u64 app_limited; /**< Delivered when app-limited detected */
427 f64 delivered_time; /**< Time last bytes were acked */
428 f64 first_tx_time; /**< Send time for recently delivered/sent */
429 tcp_byte_tracker_t *bt; /**< Tx byte tracker */
431 tcp_errors_t errors; /**< Soft connection errors */
433 f64 start_ts; /**< Timestamp when connection initialized */
434 u32 last_fib_check; /**< Last time we checked fib route for peer */
435 u16 mss; /**< Our max seg size that includes options */
436 u32 timestamp_delta; /**< Offset for timestamp */
440 struct _tcp_cc_algorithm
443 uword (*unformat_cfg) (unformat_input_t * input);
444 void (*init) (tcp_connection_t * tc);
445 void (*cleanup) (tcp_connection_t * tc);
446 void (*rcv_ack) (tcp_connection_t * tc, tcp_rate_sample_t *rs);
447 void (*rcv_cong_ack) (tcp_connection_t * tc, tcp_cc_ack_t ack,
448 tcp_rate_sample_t *rs);
449 void (*congestion) (tcp_connection_t * tc);
450 void (*loss) (tcp_connection_t * tc);
451 void (*recovered) (tcp_connection_t * tc);
452 void (*undo_recovery) (tcp_connection_t * tc);
453 void (*event) (tcp_connection_t *tc, tcp_cc_event_t evt);
454 u64 (*get_pacing_rate) (tcp_connection_t *tc);
458 #define tcp_fastrecovery_on(tc) (tc)->flags |= TCP_CONN_FAST_RECOVERY
459 #define tcp_fastrecovery_off(tc) (tc)->flags &= ~TCP_CONN_FAST_RECOVERY
460 #define tcp_recovery_on(tc) (tc)->flags |= TCP_CONN_RECOVERY
461 #define tcp_recovery_off(tc) (tc)->flags &= ~TCP_CONN_RECOVERY
462 #define tcp_in_fastrecovery(tc) ((tc)->flags & TCP_CONN_FAST_RECOVERY)
463 #define tcp_in_recovery(tc) ((tc)->flags & (TCP_CONN_RECOVERY))
464 #define tcp_in_slowstart(tc) (tc->cwnd < tc->ssthresh)
465 #define tcp_disconnect_pending(tc) ((tc)->flags & TCP_CONN_DCNT_PENDING)
466 #define tcp_disconnect_pending_on(tc) ((tc)->flags |= TCP_CONN_DCNT_PENDING)
467 #define tcp_disconnect_pending_off(tc) ((tc)->flags &= ~TCP_CONN_DCNT_PENDING)
468 #define tcp_fastrecovery_first(tc) ((tc)->flags & TCP_CONN_FRXT_FIRST)
469 #define tcp_fastrecovery_first_on(tc) ((tc)->flags |= TCP_CONN_FRXT_FIRST)
470 #define tcp_fastrecovery_first_off(tc) ((tc)->flags &= ~TCP_CONN_FRXT_FIRST)
472 #define tcp_in_cong_recovery(tc) ((tc)->flags & \
473 (TCP_CONN_FAST_RECOVERY | TCP_CONN_RECOVERY))
475 #define tcp_csum_offload(tc) (!((tc)->cfg_flags & TCP_CFG_F_NO_CSUM_OFFLOAD))
478 tcp_cong_recovery_off (tcp_connection_t * tc)
480 tc->flags &= ~(TCP_CONN_FAST_RECOVERY | TCP_CONN_RECOVERY);
481 tcp_fastrecovery_first_off (tc);
484 #define tcp_zero_rwnd_sent(tc) ((tc)->flags & TCP_CONN_ZERO_RWND_SENT)
485 #define tcp_zero_rwnd_sent_on(tc) (tc)->flags |= TCP_CONN_ZERO_RWND_SENT
486 #define tcp_zero_rwnd_sent_off(tc) (tc)->flags &= ~TCP_CONN_ZERO_RWND_SENT
488 typedef enum _tcp_error
490 #define tcp_error(n,s) TCP_ERROR_##n,
491 #include <vnet/tcp/tcp_error.def>
496 typedef struct _tcp_lookup_dispatch
499 } tcp_lookup_dispatch_t;
501 typedef struct tcp_worker_ctx_
503 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
507 /** worker timer wheel */
508 tw_timer_wheel_16t_2w_512sl_t timer_wheel;
510 /** tx buffer free list */
513 /** tx frames for ip 4/6 lookup nodes */
514 vlib_frame_t *ip_lookup_tx_frames[2];
516 /** vector of pending ack dequeues */
517 u32 *pending_deq_acked;
519 /** vector of pending disconnect notifications */
520 u32 *pending_disconnects;
522 /** convenience pointer to this thread's vlib main */
525 CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
527 /** cached 'on the wire' options for bursts */
532 typedef struct tcp_iss_seed_
538 typedef struct tcp_configuration_
540 /** Max rx fifo size for a session (in bytes). It is used in to compute the
541 * rfc 7323 window scaling factor */
544 /** Min rx fifo for a session (in bytes) */
547 /** Default MTU to be used when establishing connections */
550 /** Initial CWND multiplier, which multiplies MSS to determine initial CWND.
551 * Set 0 to determine the initial CWND by another way */
552 u16 initial_cwnd_multiplier;
554 /** Enable tx pacing for new connections */
557 /** Allow use of TSO whenever available */
560 /** Default congestion control algorithm type */
561 tcp_cc_algorithm_type_e cc_algo;
563 /** Min rwnd, as number of snd_mss segments, for update ack to be sent after
564 * a zero rwnd advertisement */
565 u32 rwnd_min_update_ack;
567 /** Delayed ack time (disabled) */
570 /** Timer ticks to wait for close from app */
573 /** Timer ticks to wait in time-wait. Also known as 2MSL */
576 /** Timer ticks to wait in fin-wait1 to send fin and rcv fin-ack */
579 /** Timer ticks to wait in last ack for ack */
582 /** Timer ticks to wait in fin-wait2 for fin */
585 /** Timer ticks to wait in closing for fin ack */
588 /** Timer ticks to wait before cleaning up the connection */
591 /** Number of preallocated connections */
592 u32 preallocated_connections;
594 /** Number of preallocated half-open connections */
595 u32 preallocated_half_open_connections;
597 /** Vectors of src addresses. Optional unless one needs > 63K active-opens */
598 ip4_address_t *ip4_src_addrs;
599 ip6_address_t *ip6_src_addrs;
601 /** Fault-injection. Debug only */
602 f64 buffer_fail_fraction;
603 } tcp_configuration_t;
605 typedef struct _tcp_main
607 /* Per-worker thread tcp connection pools */
608 tcp_connection_t **connections;
610 /* Pool of listeners. */
611 tcp_connection_t *listener_pool;
613 /** Dispatch table by state and flags */
614 tcp_lookup_dispatch_t dispatch_table[TCP_N_STATES][64];
616 u8 log2_tstamp_clocks_per_tick;
617 f64 tstamp_ticks_per_clock;
619 /** per-worker context */
620 tcp_worker_ctx_t *wrk_ctx;
622 /** Pool of half-open connections on which we've sent a SYN */
623 tcp_connection_t *half_open_connections;
624 clib_spinlock_t half_open_lock;
626 /** vlib buffer size */
627 u32 bytes_per_buffer;
629 /** Seed used to generate random iss */
630 tcp_iss_seed_t iss_seed;
632 /** Congestion control algorithms registered */
633 tcp_cc_algorithm_t *cc_algos;
635 /** Hash table of cc algorithms by name */
636 uword *cc_algo_by_name;
638 /** Last cc algo registered */
639 tcp_cc_algorithm_type_e cc_last_type;
641 /** Flag that indicates if stack is on or off */
644 /** Flag that indicates if v4 punting is enabled */
647 /** Flag that indicates if v6 punting is enabled */
650 /** Rotor for v4 source addresses */
651 u32 last_v4_addr_rotor;
653 /** Rotor for v6 source addresses */
654 u32 last_v6_addr_rotor;
656 /** Protocol configuration */
657 tcp_configuration_t cfg;
660 extern tcp_main_t tcp_main;
661 extern vlib_node_registration_t tcp4_input_node;
662 extern vlib_node_registration_t tcp6_input_node;
663 extern vlib_node_registration_t tcp4_output_node;
664 extern vlib_node_registration_t tcp6_output_node;
665 extern vlib_node_registration_t tcp4_established_node;
666 extern vlib_node_registration_t tcp6_established_node;
667 extern vlib_node_registration_t tcp4_syn_sent_node;
668 extern vlib_node_registration_t tcp6_syn_sent_node;
669 extern vlib_node_registration_t tcp4_rcv_process_node;
670 extern vlib_node_registration_t tcp6_rcv_process_node;
671 extern vlib_node_registration_t tcp4_listen_node;
672 extern vlib_node_registration_t tcp6_listen_node;
674 #define tcp_cfg tcp_main.cfg
675 #define tcp_node_index(node_id, is_ip4) \
676 ((is_ip4) ? tcp4_##node_id##_node.index : tcp6_##node_id##_node.index)
678 always_inline tcp_main_t *
684 always_inline tcp_worker_ctx_t *
685 tcp_get_worker (u32 thread_index)
687 return &tcp_main.wrk_ctx[thread_index];
690 always_inline tcp_header_t *
691 tcp_buffer_hdr (vlib_buffer_t * b)
693 ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
694 return (tcp_header_t *) (b->data + b->current_data
695 + vnet_buffer (b)->tcp.hdr_offset);
698 #if (VLIB_BUFFER_TRACE_TRAJECTORY)
699 #define tcp_trajectory_add_start(b, start) \
701 (*vlib_buffer_trace_trajectory_cb) (b, start); \
704 #define tcp_trajectory_add_start(b, start)
707 clib_error_t *vnet_tcp_enable_disable (vlib_main_t * vm, u8 is_en);
709 void tcp_punt_unknown (vlib_main_t * vm, u8 is_ip4, u8 is_add);
711 always_inline tcp_connection_t *
712 tcp_connection_get (u32 conn_index, u32 thread_index)
715 (pool_is_free_index (tcp_main.connections[thread_index], conn_index)))
717 return pool_elt_at_index (tcp_main.connections[thread_index], conn_index);
720 always_inline tcp_connection_t *
721 tcp_connection_get_if_valid (u32 conn_index, u32 thread_index)
723 if (tcp_main.connections[thread_index] == 0)
725 if (pool_is_free_index (tcp_main.connections[thread_index], conn_index))
727 return pool_elt_at_index (tcp_main.connections[thread_index], conn_index);
730 always_inline tcp_connection_t *
731 tcp_get_connection_from_transport (transport_connection_t * tconn)
733 return (tcp_connection_t *) tconn;
737 tcp_connection_set_state (tcp_connection_t * tc, tcp_state_t state)
740 TCP_EVT (TCP_EVT_STATE_CHANGE, tc);
743 void tcp_connection_close (tcp_connection_t * tc);
744 void tcp_connection_cleanup (tcp_connection_t * tc);
745 void tcp_connection_del (tcp_connection_t * tc);
746 int tcp_half_open_connection_cleanup (tcp_connection_t * tc);
747 tcp_connection_t *tcp_connection_alloc (u8 thread_index);
748 tcp_connection_t *tcp_connection_alloc_w_base (u8 thread_index,
749 tcp_connection_t * base);
750 void tcp_connection_free (tcp_connection_t * tc);
751 void tcp_connection_reset (tcp_connection_t * tc);
752 int tcp_configure_v4_source_address_range (vlib_main_t * vm,
753 ip4_address_t * start,
754 ip4_address_t * end, u32 table_id);
755 int tcp_configure_v6_source_address_range (vlib_main_t * vm,
756 ip6_address_t * start,
757 ip6_address_t * end, u32 table_id);
758 void tcp_api_reference (void);
759 u8 *format_tcp_connection (u8 * s, va_list * args);
761 always_inline tcp_connection_t *
762 tcp_listener_get (u32 tli)
764 return pool_elt_at_index (tcp_main.listener_pool, tli);
767 always_inline tcp_connection_t *
768 tcp_half_open_connection_get (u32 conn_index)
770 tcp_connection_t *tc = 0;
771 clib_spinlock_lock_if_init (&tcp_main.half_open_lock);
772 if (!pool_is_free_index (tcp_main.half_open_connections, conn_index))
773 tc = pool_elt_at_index (tcp_main.half_open_connections, conn_index);
774 clib_spinlock_unlock_if_init (&tcp_main.half_open_lock);
778 void tcp_make_fin (tcp_connection_t * tc, vlib_buffer_t * b);
779 void tcp_make_synack (tcp_connection_t * ts, vlib_buffer_t * b);
780 void tcp_send_reset_w_pkt (tcp_connection_t * tc, vlib_buffer_t * pkt,
781 u32 thread_index, u8 is_ip4);
782 void tcp_send_reset (tcp_connection_t * tc);
783 void tcp_send_syn (tcp_connection_t * tc);
784 void tcp_send_synack (tcp_connection_t * tc);
785 void tcp_send_fin (tcp_connection_t * tc);
786 void tcp_send_ack (tcp_connection_t * tc);
787 void tcp_update_burst_snd_vars (tcp_connection_t * tc);
788 void tcp_update_rto (tcp_connection_t * tc);
789 void tcp_flush_frames_to_output (tcp_worker_ctx_t * wrk);
790 void tcp_send_window_update_ack (tcp_connection_t * tc);
792 void tcp_program_ack (tcp_connection_t * tc);
793 void tcp_program_dupack (tcp_connection_t * tc);
794 void tcp_program_retransmit (tcp_connection_t * tc);
801 * Byte tracker initialize
803 * @param tc connection for which the byte tracker should be allocated and
806 void tcp_bt_init (tcp_connection_t * tc);
808 * Byte tracker cleanup
810 * @param tc connection for which the byte tracker should be cleaned up
812 void tcp_bt_cleanup (tcp_connection_t * tc);
814 * Flush byte tracker samples
816 * @param tc tcp connection for which samples should be flushed
818 void tcp_bt_flush_samples (tcp_connection_t * tc);
820 * Track a tcp tx burst
822 * @param tc tcp connection
824 void tcp_bt_track_tx (tcp_connection_t * tc, u32 len);
826 * Track a tcp retransmission
828 * @param tc tcp connection
829 * @param start start sequence number
830 * @param end end sequence number
832 void tcp_bt_track_rxt (tcp_connection_t * tc, u32 start, u32 end);
834 * Generate a delivery rate sample from recently acked bytes
836 * @param tc tcp connection
837 * @param rs resulting rate sample
839 void tcp_bt_sample_delivery_rate (tcp_connection_t * tc,
840 tcp_rate_sample_t * rs);
842 * Check if sample to be generated is app limited
844 * @param tc tcp connection
846 void tcp_bt_check_app_limited (tcp_connection_t * tc);
848 * Check if the byte tracker is in sane state
850 * Should be used only for testing
852 * @param bt byte tracker
854 int tcp_bt_is_sane (tcp_byte_tracker_t * bt);
855 u8 *format_tcp_bt (u8 * s, va_list * args);
858 tcp_end_seq (tcp_header_t * th, u32 len)
860 return th->seq_number + tcp_is_syn (th) + tcp_is_fin (th) + len;
863 /* Modulo arithmetic for TCP sequence numbers */
864 #define seq_lt(_s1, _s2) ((i32)((_s1)-(_s2)) < 0)
865 #define seq_leq(_s1, _s2) ((i32)((_s1)-(_s2)) <= 0)
866 #define seq_gt(_s1, _s2) ((i32)((_s1)-(_s2)) > 0)
867 #define seq_geq(_s1, _s2) ((i32)((_s1)-(_s2)) >= 0)
868 #define seq_max(_s1, _s2) (seq_gt((_s1), (_s2)) ? (_s1) : (_s2))
870 /* Modulo arithmetic for timestamps */
871 #define timestamp_lt(_t1, _t2) ((i32)((_t1)-(_t2)) < 0)
872 #define timestamp_leq(_t1, _t2) ((i32)((_t1)-(_t2)) <= 0)
875 * Our estimate of the number of bytes that have left the network
878 tcp_bytes_out (const tcp_connection_t * tc)
880 if (tcp_opts_sack_permitted (&tc->rcv_opts))
881 return tc->sack_sb.sacked_bytes + tc->sack_sb.lost_bytes;
883 return tc->rcv_dupacks * tc->snd_mss;
887 * Our estimate of the number of bytes in flight (pipe size)
890 tcp_flight_size (const tcp_connection_t * tc)
894 flight_size = (int) (tc->snd_nxt - tc->snd_una) - tcp_bytes_out (tc)
895 + tc->snd_rxt_bytes - tc->rxt_delivered;
897 ASSERT (flight_size >= 0);
903 * Initial cwnd as per RFC5681
906 tcp_initial_cwnd (const tcp_connection_t * tc)
908 if (tcp_cfg.initial_cwnd_multiplier > 0)
909 return tcp_cfg.initial_cwnd_multiplier * tc->snd_mss;
911 if (tc->snd_mss > 2190)
912 return 2 * tc->snd_mss;
913 else if (tc->snd_mss > 1095)
914 return 3 * tc->snd_mss;
916 return 4 * tc->snd_mss;
920 * Accumulate acked bytes for cwnd increase
922 * Once threshold bytes are accumulated, snd_mss bytes are added
926 tcp_cwnd_accumulate (tcp_connection_t * tc, u32 thresh, u32 bytes)
928 tc->cwnd_acc_bytes += bytes;
929 if (tc->cwnd_acc_bytes >= thresh)
931 u32 inc = tc->cwnd_acc_bytes / thresh;
932 tc->cwnd_acc_bytes -= inc * thresh;
933 tc->cwnd += inc * tc->snd_mss;
934 tc->cwnd = clib_min (tc->cwnd, tc->tx_fifo_size);
939 tcp_loss_wnd (const tcp_connection_t * tc)
941 /* Whatever we have in flight + the packet we're about to send */
942 return tcp_flight_size (tc) + tc->snd_mss;
946 tcp_available_snd_wnd (const tcp_connection_t * tc)
948 return clib_min (tc->cwnd, tc->snd_wnd);
952 tcp_available_output_snd_space (const tcp_connection_t * tc)
954 u32 available_wnd = tcp_available_snd_wnd (tc);
955 int flight_size = (int) (tc->snd_nxt - tc->snd_una);
957 if (available_wnd <= flight_size)
960 return available_wnd - flight_size;
964 * Estimate of how many bytes we can still push into the network
967 tcp_available_cc_snd_space (const tcp_connection_t * tc)
969 u32 available_wnd = tcp_available_snd_wnd (tc);
970 u32 flight_size = tcp_flight_size (tc);
972 if (available_wnd <= flight_size)
975 return available_wnd - flight_size;
979 tcp_is_lost_fin (tcp_connection_t * tc)
981 if ((tc->flags & TCP_CONN_FINSNT) && (tc->snd_una_max - tc->snd_una == 1))
986 u32 tcp_snd_space (tcp_connection_t * tc);
987 int tcp_fastrecovery_prr_snd_space (tcp_connection_t * tc);
989 fib_node_index_t tcp_lookup_rmt_in_fib (tcp_connection_t * tc);
991 /* Made public for unit testing only */
992 void tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end);
993 u32 tcp_sack_list_bytes (tcp_connection_t * tc);
998 return tcp_main.wrk_ctx[vlib_get_thread_index ()].time_now;
1002 tcp_time_now_w_thread (u32 thread_index)
1004 return tcp_main.wrk_ctx[thread_index].time_now;
1008 * Generate timestamp for tcp connection
1011 tcp_tstamp (tcp_connection_t * tc)
1013 return (tcp_main.wrk_ctx[tc->c_thread_index].time_now -
1014 tc->timestamp_delta);
1018 tcp_time_now_us (u32 thread_index)
1020 return transport_time_now (thread_index);
1024 tcp_set_time_now (tcp_worker_ctx_t * wrk)
1026 wrk->time_now = clib_cpu_time_now () * tcp_main.tstamp_ticks_per_clock;
1027 return wrk->time_now;
1030 u32 tcp_session_push_header (transport_connection_t * tconn,
1032 int tcp_session_custom_tx (void *conn, u32 max_burst_size);
1034 void tcp_connection_timers_init (tcp_connection_t * tc);
1035 void tcp_connection_timers_reset (tcp_connection_t * tc);
1036 void tcp_init_snd_vars (tcp_connection_t * tc);
1037 void tcp_connection_init_vars (tcp_connection_t * tc);
1038 void tcp_connection_tx_pacer_update (tcp_connection_t * tc);
1039 void tcp_connection_tx_pacer_reset (tcp_connection_t * tc, u32 window,
1043 tcp_cc_rcv_ack (tcp_connection_t * tc, tcp_rate_sample_t * rs)
1045 tc->cc_algo->rcv_ack (tc, rs);
1046 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1050 tcp_cc_rcv_cong_ack (tcp_connection_t * tc, tcp_cc_ack_t ack_type,
1051 tcp_rate_sample_t * rs)
1053 tc->cc_algo->rcv_cong_ack (tc, ack_type, rs);
1057 tcp_cc_congestion (tcp_connection_t * tc)
1059 tc->cc_algo->congestion (tc);
1063 tcp_cc_loss (tcp_connection_t * tc)
1065 tc->cc_algo->loss (tc);
1069 tcp_cc_recovered (tcp_connection_t * tc)
1071 tc->cc_algo->recovered (tc);
1075 tcp_cc_undo_recovery (tcp_connection_t * tc)
1077 if (tc->cc_algo->undo_recovery)
1078 tc->cc_algo->undo_recovery (tc);
1082 tcp_cc_event (tcp_connection_t * tc, tcp_cc_event_t evt)
1084 if (tc->cc_algo->event)
1085 tc->cc_algo->event (tc, evt);
1089 tcp_cc_get_pacing_rate (tcp_connection_t * tc)
1091 if (tc->cc_algo->get_pacing_rate)
1092 return tc->cc_algo->get_pacing_rate (tc);
1094 f64 srtt = clib_min ((f64) tc->srtt * TCP_TICK, tc->mrtt_us);
1096 /* TODO should constrain to interface's max throughput but
1097 * we don't have link speeds for sw ifs ..*/
1098 return ((f64) tc->cwnd / srtt);
1102 tcp_timer_set (tcp_connection_t * tc, u8 timer_id, u32 interval)
1104 ASSERT (tc->c_thread_index == vlib_get_thread_index ());
1105 ASSERT (tc->timers[timer_id] == TCP_TIMER_HANDLE_INVALID);
1106 tc->timers[timer_id] =
1107 tw_timer_start_16t_2w_512sl (&tcp_main.
1108 wrk_ctx[tc->c_thread_index].timer_wheel,
1109 tc->c_c_index, timer_id, interval);
1113 tcp_timer_reset (tcp_connection_t * tc, u8 timer_id)
1115 ASSERT (tc->c_thread_index == vlib_get_thread_index ());
1116 if (tc->timers[timer_id] == TCP_TIMER_HANDLE_INVALID)
1119 tw_timer_stop_16t_2w_512sl (&tcp_main.
1120 wrk_ctx[tc->c_thread_index].timer_wheel,
1121 tc->timers[timer_id]);
1122 tc->timers[timer_id] = TCP_TIMER_HANDLE_INVALID;
1126 tcp_timer_update (tcp_connection_t * tc, u8 timer_id, u32 interval)
1128 ASSERT (tc->c_thread_index == vlib_get_thread_index ());
1129 if (tc->timers[timer_id] != TCP_TIMER_HANDLE_INVALID)
1130 tw_timer_update_16t_2w_512sl (&tcp_main.
1131 wrk_ctx[tc->c_thread_index].timer_wheel,
1132 tc->timers[timer_id], interval);
1134 tc->timers[timer_id] =
1135 tw_timer_start_16t_2w_512sl (&tcp_main.
1136 wrk_ctx[tc->c_thread_index].timer_wheel,
1137 tc->c_c_index, timer_id, interval);
1141 tcp_retransmit_timer_set (tcp_connection_t * tc)
1143 ASSERT (tc->snd_una != tc->snd_una_max);
1144 tcp_timer_set (tc, TCP_TIMER_RETRANSMIT,
1145 clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
1149 tcp_retransmit_timer_reset (tcp_connection_t * tc)
1151 tcp_timer_reset (tc, TCP_TIMER_RETRANSMIT);
1155 tcp_retransmit_timer_force_update (tcp_connection_t * tc)
1157 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT,
1158 clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
1162 tcp_persist_timer_set (tcp_connection_t * tc)
1164 /* Reuse RTO. It's backed off in handler */
1165 tcp_timer_set (tc, TCP_TIMER_PERSIST,
1166 clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
1170 tcp_persist_timer_update (tcp_connection_t * tc)
1172 tcp_timer_update (tc, TCP_TIMER_PERSIST,
1173 clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
1177 tcp_persist_timer_reset (tcp_connection_t * tc)
1179 tcp_timer_reset (tc, TCP_TIMER_PERSIST);
1183 tcp_retransmit_timer_update (tcp_connection_t * tc)
1185 if (tc->snd_una == tc->snd_nxt)
1187 tcp_retransmit_timer_reset (tc);
1188 if (tc->snd_wnd < tc->snd_mss)
1189 tcp_persist_timer_update (tc);
1192 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT,
1193 clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
1197 tcp_timer_is_active (tcp_connection_t * tc, tcp_timers_e timer)
1199 return tc->timers[timer] != TCP_TIMER_HANDLE_INVALID;
1202 #define tcp_validate_txf_size(_tc, _a) \
1203 ASSERT(_tc->state != TCP_STATE_ESTABLISHED \
1204 || transport_max_tx_dequeue (&_tc->connection) >= _a)
1206 void tcp_rcv_sacks (tcp_connection_t * tc, u32 ack);
1207 u8 *tcp_scoreboard_replay (u8 * s, tcp_connection_t * tc, u8 verbose);
1210 * Register exiting cc algo type
1212 void tcp_cc_algo_register (tcp_cc_algorithm_type_e type,
1213 const tcp_cc_algorithm_t * vft);
1216 * Register new cc algo type
1218 tcp_cc_algorithm_type_e tcp_cc_algo_new_type (const tcp_cc_algorithm_t * vft);
1219 tcp_cc_algorithm_t *tcp_cc_algo_get (tcp_cc_algorithm_type_e type);
1221 static inline void *
1222 tcp_cc_data (tcp_connection_t * tc)
1224 return (void *) tc->cc_data;
1227 void newreno_rcv_cong_ack (tcp_connection_t * tc, tcp_cc_ack_t ack_type,
1228 tcp_rate_sample_t * rs);
1231 * Push TCP header to buffer
1233 * @param vm - vlib_main
1234 * @param b - buffer to write the header to
1235 * @param sp_net - source port net order
1236 * @param dp_net - destination port net order
1237 * @param seq - sequence number net order
1238 * @param ack - ack number net order
1239 * @param tcp_hdr_opts_len - header and options length in bytes
1240 * @param flags - header flags
1241 * @param wnd - window size
1243 * @return - pointer to start of TCP header
1245 always_inline void *
1246 vlib_buffer_push_tcp_net_order (vlib_buffer_t * b, u16 sp, u16 dp, u32 seq,
1247 u32 ack, u8 tcp_hdr_opts_len, u8 flags,
1252 th = vlib_buffer_push_uninit (b, tcp_hdr_opts_len);
1256 th->seq_number = seq;
1257 th->ack_number = ack;
1258 th->data_offset_and_reserved = (tcp_hdr_opts_len >> 2) << 4;
1262 th->urgent_pointer = 0;
1263 vnet_buffer (b)->l4_hdr_offset = (u8 *) th - b->data;
1264 b->flags |= VNET_BUFFER_F_L4_HDR_OFFSET_VALID;
1269 * Push TCP header to buffer
1271 * @param b - buffer to write the header to
1272 * @param sp_net - source port net order
1273 * @param dp_net - destination port net order
1274 * @param seq - sequence number host order
1275 * @param ack - ack number host order
1276 * @param tcp_hdr_opts_len - header and options length in bytes
1277 * @param flags - header flags
1278 * @param wnd - window size
1280 * @return - pointer to start of TCP header
1282 always_inline void *
1283 vlib_buffer_push_tcp (vlib_buffer_t * b, u16 sp_net, u16 dp_net, u32 seq,
1284 u32 ack, u8 tcp_hdr_opts_len, u8 flags, u16 wnd)
1286 return vlib_buffer_push_tcp_net_order (b, sp_net, dp_net,
1287 clib_host_to_net_u32 (seq),
1288 clib_host_to_net_u32 (ack),
1289 tcp_hdr_opts_len, flags,
1290 clib_host_to_net_u16 (wnd));
1293 #endif /* _vnet_tcp_h_ */
1296 * fd.io coding-style-patch-verification: ON
1299 * eval: (c-set-style "gnu")