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 10e-3 /**< TCP tick period (s) */
28 #define THZ 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_MAX_OPTION_SPACE 40
33 #define TCP_DUPACK_THRESHOLD 3
34 #define TCP_MAX_RX_FIFO_SIZE 2 << 20
35 #define TCP_IW_N_SEGMENTS 10
36 #define TCP_ALWAYS_ACK 0 /**< If on, we always ack */
38 /** TCP FSM state definitions as per RFC793. */
39 #define foreach_tcp_fsm_state \
42 _(SYN_SENT, "SYN_SENT") \
43 _(SYN_RCVD, "SYN_RCVD") \
44 _(ESTABLISHED, "ESTABLISHED") \
45 _(CLOSE_WAIT, "CLOSE_WAIT") \
46 _(FIN_WAIT_1, "FIN_WAIT_1") \
47 _(LAST_ACK, "LAST_ACK") \
48 _(CLOSING, "CLOSING") \
49 _(FIN_WAIT_2, "FIN_WAIT_2") \
50 _(TIME_WAIT, "TIME_WAIT")
52 typedef enum _tcp_state
54 #define _(sym, str) TCP_STATE_##sym,
60 format_function_t format_tcp_state;
63 #define foreach_tcp_timer \
64 _(RETRANSMIT, "RETRANSMIT") \
65 _(DELACK, "DELAYED ACK") \
66 _(PERSIST, "PERSIST") \
68 _(WAITCLOSE, "WAIT CLOSE") \
69 _(RETRANSMIT_SYN, "RETRANSMIT SYN") \
70 _(ESTABLISH, "ESTABLISH")
72 typedef enum _tcp_timers
74 #define _(sym, str) TCP_TIMER_##sym,
80 typedef void (timer_expiration_handler) (u32 index);
82 extern timer_expiration_handler tcp_timer_delack_handler;
83 extern timer_expiration_handler tcp_timer_retransmit_handler;
84 extern timer_expiration_handler tcp_timer_persist_handler;
85 extern timer_expiration_handler tcp_timer_retransmit_syn_handler;
87 #define TCP_TIMER_HANDLE_INVALID ((u32) ~0)
89 /* Timer delays as multiples of 100ms */
90 #define TCP_TO_TIMER_TICK TCP_TICK*10 /* Period for converting from TCP
91 * ticks to timer units */
92 #define TCP_DELACK_TIME 1 /* 0.1s */
93 #define TCP_ESTABLISH_TIME 750 /* 75s */
94 #define TCP_2MSL_TIME 300 /* 30s */
95 #define TCP_CLOSEWAIT_TIME 1 /* 0.1s */
96 #define TCP_CLEANUP_TIME 5 /* 0.5s Time to wait before cleanup */
97 #define TCP_TIMER_PERSIST_MIN 2 /* 0.2s */
99 #define TCP_RTO_MAX 60 * THZ /* Min max RTO (60s) as per RFC6298 */
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 */
104 /** TCP connection flags */
105 #define foreach_tcp_connection_flag \
106 _(SNDACK, "Send ACK") \
107 _(FINSNT, "FIN sent") \
108 _(SENT_RCV_WND0, "Sent 0 receive window") \
109 _(RECOVERY, "Recovery on") \
110 _(FAST_RECOVERY, "Fast Recovery on") \
111 _(FR_1_SMSS, "Sent 1 SMSS")
113 typedef enum _tcp_connection_flag_bits
115 #define _(sym, str) TCP_CONN_##sym##_BIT,
116 foreach_tcp_connection_flag
119 } tcp_connection_flag_bits_e;
121 typedef enum _tcp_connection_flag
123 #define _(sym, str) TCP_CONN_##sym = 1 << TCP_CONN_##sym##_BIT,
124 foreach_tcp_connection_flag
127 } tcp_connection_flags_e;
129 /** TCP buffer flags */
130 #define foreach_tcp_buf_flag \
131 _ (ACK) /**< Sending ACK. */ \
132 _ (DUPACK) /**< Sending DUPACK. */ \
136 #define _(f) TCP_BUF_BIT_##f,
144 #define _(f) TCP_BUF_FLAG_##f = 1 << TCP_BUF_BIT_##f,
149 #define TCP_MAX_SACK_BLOCKS 5 /**< Max number of SACK blocks stored */
150 #define TCP_INVALID_SACK_HOLE_INDEX ((u32)~0)
152 typedef struct _sack_scoreboard_hole
154 u32 next; /**< Index for next entry in linked list */
155 u32 prev; /**< Index for previous entry in linked list */
156 u32 start; /**< Start sequence number */
157 u32 end; /**< End sequence number */
158 } sack_scoreboard_hole_t;
160 typedef struct _sack_scoreboard
162 sack_scoreboard_hole_t *holes; /**< Pool of holes */
163 u32 head; /**< Index of first entry */
164 u32 tail; /**< Index of last entry */
165 u32 sacked_bytes; /**< Number of bytes sacked in sb */
166 u32 last_sacked_bytes; /**< Number of bytes last sacked */
167 u32 snd_una_adv; /**< Bytes to add to snd_una */
168 u32 max_byte_sacked; /**< Highest byte acked */
171 typedef enum _tcp_cc_algorithm_type
174 } tcp_cc_algorithm_type_e;
176 typedef struct _tcp_cc_algorithm tcp_cc_algorithm_t;
178 typedef enum _tcp_cc_ack_t
185 typedef struct _tcp_connection
187 transport_connection_t connection; /**< Common transport data. First! */
189 u8 state; /**< TCP state as per tcp_state_t */
190 u16 flags; /**< Connection flags (see tcp_conn_flags_e) */
191 u32 timers[TCP_N_TIMERS]; /**< Timer handles into timer wheel */
195 /** Send sequence variables RFC793 */
196 u32 snd_una; /**< oldest unacknowledged sequence number */
197 u32 snd_una_max; /**< newest unacknowledged sequence number + 1*/
198 u32 snd_wnd; /**< send window */
199 u32 snd_wl1; /**< seq number used for last snd.wnd update */
200 u32 snd_wl2; /**< ack number used for last snd.wnd update */
201 u32 snd_nxt; /**< next seq number to be sent */
203 /** Receive sequence variables RFC793 */
204 u32 rcv_nxt; /**< next sequence number expected */
205 u32 rcv_wnd; /**< receive window we expect */
207 u32 rcv_las; /**< rcv_nxt at last ack sent/rcv_wnd update */
208 u32 iss; /**< initial sent sequence */
209 u32 irs; /**< initial remote sequence */
212 tcp_options_t opt; /**< TCP connection options parsed */
213 u8 rcv_wscale; /**< Window scale to advertise to peer */
214 u8 snd_wscale; /**< Window scale to use when sending */
215 u32 tsval_recent; /**< Last timestamp received */
216 u32 tsval_recent_age; /**< When last updated tstamp_recent*/
218 sack_block_t *snd_sacks; /**< Vector of SACKs to send. XXX Fixed size? */
219 sack_scoreboard_t sack_sb; /**< SACK "scoreboard" that tracks holes */
221 u16 rcv_dupacks; /**< Number of DUPACKs received */
222 u8 snt_dupacks; /**< Number of DUPACKs sent in a burst */
224 /* Congestion control */
225 u32 cwnd; /**< Congestion window */
226 u32 ssthresh; /**< Slow-start threshold */
227 u32 prev_ssthresh; /**< ssthresh before congestion */
228 u32 bytes_acked; /**< Bytes acknowledged by current segment */
229 u32 rtx_bytes; /**< Retransmitted bytes */
230 u32 tsecr_last_ack; /**< Timestamp echoed to us in last healthy ACK */
231 u32 snd_congestion; /**< snd_una_max when congestion is detected */
232 tcp_cc_algorithm_t *cc_algo; /**< Congestion control algorithm */
235 u32 rto; /**< Retransmission timeout */
236 u32 rto_boff; /**< Index for RTO backoff */
237 u32 srtt; /**< Smoothed RTT */
238 u32 rttvar; /**< Smoothed mean RTT difference. Approximates variance */
239 u32 rtt_ts; /**< Timestamp for tracked ACK */
240 u32 rtt_seq; /**< Sequence number for tracked ACK */
242 u16 snd_mss; /**< Send MSS */
245 struct _tcp_cc_algorithm
247 void (*rcv_ack) (tcp_connection_t * tc);
248 void (*rcv_cong_ack) (tcp_connection_t * tc, tcp_cc_ack_t ack);
249 void (*congestion) (tcp_connection_t * tc);
250 void (*recovered) (tcp_connection_t * tc);
251 void (*init) (tcp_connection_t * tc);
254 #define tcp_fastrecovery_on(tc) (tc)->flags |= TCP_CONN_FAST_RECOVERY
255 #define tcp_fastrecovery_off(tc) (tc)->flags &= ~TCP_CONN_FAST_RECOVERY
256 #define tcp_recovery_on(tc) (tc)->flags |= TCP_CONN_RECOVERY
257 #define tcp_recovery_off(tc) (tc)->flags &= ~TCP_CONN_RECOVERY
258 #define tcp_in_fastrecovery(tc) ((tc)->flags & TCP_CONN_FAST_RECOVERY)
259 #define tcp_in_recovery(tc) ((tc)->flags & (TCP_CONN_RECOVERY))
260 #define tcp_in_slowstart(tc) (tc->cwnd < tc->ssthresh)
261 #define tcp_fastrecovery_sent_1_smss(tc) ((tc)->flags & TCP_CONN_FR_1_SMSS)
262 #define tcp_fastrecovery_1_smss_on(tc) ((tc)->flags |= TCP_CONN_FR_1_SMSS)
263 #define tcp_fastrecovery_1_smss_off(tc) ((tc)->flags &= ~TCP_CONN_FR_1_SMSS)
265 #define tcp_in_cong_recovery(tc) ((tc)->flags & \
266 (TCP_CONN_FAST_RECOVERY | TCP_CONN_RECOVERY))
269 tcp_cong_recovery_off (tcp_connection_t * tc)
271 tc->flags &= ~(TCP_CONN_FAST_RECOVERY | TCP_CONN_RECOVERY);
272 tcp_fastrecovery_1_smss_off (tc);
282 typedef enum _tcp_error
284 #define tcp_error(n,s) TCP_ERROR_##n,
285 #include <vnet/tcp/tcp_error.def>
290 typedef struct _tcp_lookup_dispatch
293 } tcp_lookup_dispatch_t;
295 typedef struct _tcp_main
297 /* Per-worker thread tcp connection pools */
298 tcp_connection_t **connections;
300 /* Pool of listeners. */
301 tcp_connection_t *listener_pool;
303 /** Dispatch table by state and flags */
304 tcp_lookup_dispatch_t dispatch_table[TCP_N_STATES][64];
306 u8 log2_tstamp_clocks_per_tick;
307 f64 tstamp_ticks_per_clock;
309 /** per-worker tx buffer free lists */
312 /* Per worker-thread timer wheel for connections timers */
313 tw_timer_wheel_16t_2w_512sl_t *timer_wheels;
315 // /* Convenience per worker-thread vector of connections to DELACK */
316 // u32 **delack_connections;
318 /* Pool of half-open connections on which we've sent a SYN */
319 tcp_connection_t *half_open_connections;
321 /* Pool of local TCP endpoints */
322 transport_endpoint_t *local_endpoints;
324 /* Local endpoints lookup table */
325 transport_endpoint_table_t local_endpoints_table;
327 /* Congestion control algorithms registered */
328 tcp_cc_algorithm_t *cc_algos;
330 /* Flag that indicates if stack is on or off */
334 vlib_main_t *vlib_main;
335 vnet_main_t *vnet_main;
336 ip4_main_t *ip4_main;
337 ip6_main_t *ip6_main;
340 extern tcp_main_t tcp_main;
341 extern vlib_node_registration_t tcp4_input_node;
342 extern vlib_node_registration_t tcp6_input_node;
343 extern vlib_node_registration_t tcp4_output_node;
344 extern vlib_node_registration_t tcp6_output_node;
346 always_inline tcp_main_t *
352 clib_error_t *vnet_tcp_enable_disable (vlib_main_t * vm, u8 is_en);
354 always_inline tcp_connection_t *
355 tcp_connection_get (u32 conn_index, u32 thread_index)
357 if (pool_is_free_index (tcp_main.connections[thread_index], conn_index))
359 return pool_elt_at_index (tcp_main.connections[thread_index], conn_index);
362 always_inline tcp_connection_t *
363 tcp_connection_get_if_valid (u32 conn_index, u32 thread_index)
365 if (tcp_main.connections[thread_index] == 0)
367 if (pool_is_free_index (tcp_main.connections[thread_index], conn_index))
369 return pool_elt_at_index (tcp_main.connections[thread_index], conn_index);
372 void tcp_connection_close (tcp_connection_t * tc);
373 void tcp_connection_cleanup (tcp_connection_t * tc);
374 void tcp_connection_del (tcp_connection_t * tc);
375 void tcp_connection_reset (tcp_connection_t * tc);
377 u8 *format_tcp_connection (u8 * s, va_list * args);
378 u8 *format_tcp_connection_verbose (u8 * s, va_list * args);
380 always_inline tcp_connection_t *
381 tcp_listener_get (u32 tli)
383 return pool_elt_at_index (tcp_main.listener_pool, tli);
386 always_inline tcp_connection_t *
387 tcp_half_open_connection_get (u32 conn_index)
389 return pool_elt_at_index (tcp_main.half_open_connections, conn_index);
392 void tcp_make_ack (tcp_connection_t * ts, vlib_buffer_t * b);
393 void tcp_make_fin (tcp_connection_t * tc, vlib_buffer_t * b);
394 void tcp_make_synack (tcp_connection_t * ts, vlib_buffer_t * b);
395 void tcp_send_reset (vlib_buffer_t * pkt, u8 is_ip4);
396 void tcp_send_syn (tcp_connection_t * tc);
397 void tcp_send_fin (tcp_connection_t * tc);
398 void tcp_set_snd_mss (tcp_connection_t * tc);
401 tcp_end_seq (tcp_header_t * th, u32 len)
403 return th->seq_number + tcp_is_syn (th) + tcp_is_fin (th) + len;
406 /* Modulo arithmetic for TCP sequence numbers */
407 #define seq_lt(_s1, _s2) ((i32)((_s1)-(_s2)) < 0)
408 #define seq_leq(_s1, _s2) ((i32)((_s1)-(_s2)) <= 0)
409 #define seq_gt(_s1, _s2) ((i32)((_s1)-(_s2)) > 0)
410 #define seq_geq(_s1, _s2) ((i32)((_s1)-(_s2)) >= 0)
412 /* Modulo arithmetic for timestamps */
413 #define timestamp_lt(_t1, _t2) ((i32)((_t1)-(_t2)) < 0)
414 #define timestamp_leq(_t1, _t2) ((i32)((_t1)-(_t2)) <= 0)
417 tcp_flight_size (const tcp_connection_t * tc)
421 flight_size = (int) ((tc->snd_una_max - tc->snd_una) + tc->rtx_bytes)
422 - (tc->rcv_dupacks * tc->snd_mss) /* - tc->sack_sb.sacked_bytes */ ;
424 /* Happens if we don't clear sacked bytes */
432 * Initial cwnd as per RFC5681
435 tcp_initial_cwnd (const tcp_connection_t * tc)
437 if (tc->snd_mss > 2190)
438 return 2 * tc->snd_mss;
439 else if (tc->snd_mss > 1095)
440 return 3 * tc->snd_mss;
442 return 4 * tc->snd_mss;
446 tcp_loss_wnd (const tcp_connection_t * tc)
452 tcp_available_wnd (const tcp_connection_t * tc)
454 return clib_min (tc->cwnd, tc->snd_wnd);
458 tcp_available_snd_space (const tcp_connection_t * tc)
460 u32 available_wnd = tcp_available_wnd (tc);
461 u32 flight_size = tcp_flight_size (tc);
463 if (available_wnd <= flight_size)
466 return available_wnd - flight_size;
469 void tcp_update_rcv_wnd (tcp_connection_t * tc);
471 void tcp_retransmit_first_unacked (tcp_connection_t * tc);
473 void tcp_fast_retransmit (tcp_connection_t * tc);
474 void tcp_cc_congestion (tcp_connection_t * tc);
475 void tcp_cc_recover (tcp_connection_t * tc);
480 return clib_cpu_time_now () * tcp_main.tstamp_ticks_per_clock;
484 tcp_update_time (f64 now, u32 thread_index)
486 tw_timer_expire_timers_16t_2w_512sl (&tcp_main.timer_wheels[thread_index],
490 u32 tcp_push_header (transport_connection_t * tconn, vlib_buffer_t * b);
493 tcp_prepare_retransmit_segment (tcp_connection_t * tc, vlib_buffer_t * b,
494 u32 offset, u32 max_bytes);
496 void tcp_connection_timers_init (tcp_connection_t * tc);
497 void tcp_connection_timers_reset (tcp_connection_t * tc);
499 void tcp_connection_init_vars (tcp_connection_t * tc);
502 tcp_connection_force_ack (tcp_connection_t * tc, vlib_buffer_t * b)
504 /* Reset flags, make sure ack is sent */
505 tc->flags = TCP_CONN_SNDACK;
506 vnet_buffer (b)->tcp.flags &= ~TCP_BUF_FLAG_DUPACK;
510 tcp_timer_set (tcp_connection_t * tc, u8 timer_id, u32 interval)
513 = tw_timer_start_16t_2w_512sl (&tcp_main.timer_wheels[tc->c_thread_index],
514 tc->c_c_index, timer_id, interval);
518 tcp_timer_reset (tcp_connection_t * tc, u8 timer_id)
520 if (tc->timers[timer_id] == TCP_TIMER_HANDLE_INVALID)
523 tw_timer_stop_16t_2w_512sl (&tcp_main.timer_wheels[tc->c_thread_index],
524 tc->timers[timer_id]);
525 tc->timers[timer_id] = TCP_TIMER_HANDLE_INVALID;
529 tcp_timer_update (tcp_connection_t * tc, u8 timer_id, u32 interval)
531 if (tc->timers[timer_id] != TCP_TIMER_HANDLE_INVALID)
532 tw_timer_stop_16t_2w_512sl (&tcp_main.timer_wheels[tc->c_thread_index],
533 tc->timers[timer_id]);
534 tc->timers[timer_id] =
535 tw_timer_start_16t_2w_512sl (&tcp_main.timer_wheels[tc->c_thread_index],
536 tc->c_c_index, timer_id, interval);
539 /* XXX Switch retransmit to faster TW */
541 tcp_retransmit_timer_set (tcp_connection_t * tc)
543 tcp_timer_set (tc, TCP_TIMER_RETRANSMIT,
544 clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
548 tcp_retransmit_timer_update (tcp_connection_t * tc)
550 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT,
551 clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
555 tcp_retransmit_timer_reset (tcp_connection_t * tc)
557 tcp_timer_reset (tc, TCP_TIMER_RETRANSMIT);
561 tcp_persist_timer_set (tcp_connection_t * tc)
563 /* Reuse RTO. It's backed off in handler */
564 tcp_timer_set (tc, TCP_TIMER_PERSIST,
565 clib_max (tc->rto * TCP_TO_TIMER_TICK,
566 TCP_TIMER_PERSIST_MIN));
570 tcp_persist_timer_update (tcp_connection_t * tc)
572 tcp_timer_update (tc, TCP_TIMER_PERSIST,
573 clib_max (tc->rto * TCP_TO_TIMER_TICK,
574 TCP_TIMER_PERSIST_MIN));
578 tcp_persist_timer_reset (tcp_connection_t * tc)
580 tcp_timer_reset (tc, TCP_TIMER_PERSIST);
584 tcp_timer_is_active (tcp_connection_t * tc, tcp_timers_e timer)
586 return tc->timers[timer] != TCP_TIMER_HANDLE_INVALID;
590 scoreboard_remove_hole (sack_scoreboard_t * sb,
591 sack_scoreboard_hole_t * hole);
593 always_inline sack_scoreboard_hole_t *
594 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
596 if (index != TCP_INVALID_SACK_HOLE_INDEX)
597 return pool_elt_at_index (sb->holes, index);
601 always_inline sack_scoreboard_hole_t *
602 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
604 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
605 return pool_elt_at_index (sb->holes, hole->next);
609 always_inline sack_scoreboard_hole_t *
610 scoreboard_first_hole (sack_scoreboard_t * sb)
612 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
613 return pool_elt_at_index (sb->holes, sb->head);
617 always_inline sack_scoreboard_hole_t *
618 scoreboard_last_hole (sack_scoreboard_t * sb)
620 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
621 return pool_elt_at_index (sb->holes, sb->tail);
626 scoreboard_clear (sack_scoreboard_t * sb)
628 sack_scoreboard_hole_t *hole = scoreboard_first_hole (sb);
629 while ((hole = scoreboard_first_hole (sb)))
631 scoreboard_remove_hole (sb, hole);
633 sb->sacked_bytes = 0;
634 sb->last_sacked_bytes = 0;
636 sb->max_byte_sacked = 0;
640 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
642 return hole->end - hole->start;
646 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
648 return hole - sb->holes;
652 scoreboard_init (sack_scoreboard_t * sb)
654 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
655 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
658 void tcp_rcv_sacks (tcp_connection_t * tc, u32 ack);
661 tcp_cc_algo_register (tcp_cc_algorithm_type_e type,
662 const tcp_cc_algorithm_t * vft)
664 tcp_main_t *tm = vnet_get_tcp_main ();
665 vec_validate (tm->cc_algos, type);
667 tm->cc_algos[type] = *vft;
670 always_inline tcp_cc_algorithm_t *
671 tcp_cc_algo_get (tcp_cc_algorithm_type_e type)
673 tcp_main_t *tm = vnet_get_tcp_main ();
674 return &tm->cc_algos[type];
677 void tcp_cc_init (tcp_connection_t * tc);
680 * Push TCP header to buffer
682 * @param vm - vlib_main
683 * @param b - buffer to write the header to
684 * @param sp_net - source port net order
685 * @param dp_net - destination port net order
686 * @param seq - sequence number net order
687 * @param ack - ack number net order
688 * @param tcp_hdr_opts_len - header and options length in bytes
689 * @param flags - header flags
690 * @param wnd - window size
692 * @return - pointer to start of TCP header
695 vlib_buffer_push_tcp_net_order (vlib_buffer_t * b, u16 sp, u16 dp, u32 seq,
696 u32 ack, u8 tcp_hdr_opts_len, u8 flags,
701 th = vlib_buffer_push_uninit (b, tcp_hdr_opts_len);
705 th->seq_number = seq;
706 th->ack_number = ack;
707 th->data_offset_and_reserved = (tcp_hdr_opts_len >> 2) << 4;
711 th->urgent_pointer = 0;
716 * Push TCP header to buffer
718 * @param b - buffer to write the header to
719 * @param sp_net - source port net order
720 * @param dp_net - destination port net order
721 * @param seq - sequence number host order
722 * @param ack - ack number host order
723 * @param tcp_hdr_opts_len - header and options length in bytes
724 * @param flags - header flags
725 * @param wnd - window size
727 * @return - pointer to start of TCP header
730 vlib_buffer_push_tcp (vlib_buffer_t * b, u16 sp_net, u16 dp_net, u32 seq,
731 u32 ack, u8 tcp_hdr_opts_len, u8 flags, u16 wnd)
733 return vlib_buffer_push_tcp_net_order (b, sp_net, dp_net,
734 clib_host_to_net_u32 (seq),
735 clib_host_to_net_u32 (ack),
736 tcp_hdr_opts_len, flags,
737 clib_host_to_net_u16 (wnd));
740 #endif /* _vnet_tcp_h_ */
743 * fd.io coding-style-patch-verification: ON
746 * eval: (c-set-style "gnu")