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 */
98 #define TCP_RTO_MAX 60 * THZ /* Min max RTO (60s) as per RFC6298 */
99 #define TCP_RTT_MAX 30 * THZ /* 30s (probably too much) */
100 #define TCP_RTO_SYN_RETRIES 3 /* SYN retries without doubling RTO */
101 #define TCP_RTO_INIT 1 * THZ /* Initial retransmit timer */
103 void tcp_update_time (f64 now, u32 thread_index);
105 /** TCP connection flags */
106 #define foreach_tcp_connection_flag \
107 _(SNDACK, "Send ACK") \
108 _(FINSNT, "FIN sent") \
109 _(SENT_RCV_WND0, "Sent 0 receive window") \
110 _(RECOVERY, "Recovery on") \
111 _(FAST_RECOVERY, "Fast Recovery on") \
112 _(FR_1_SMSS, "Sent 1 SMSS")
114 typedef enum _tcp_connection_flag_bits
116 #define _(sym, str) TCP_CONN_##sym##_BIT,
117 foreach_tcp_connection_flag
120 } tcp_connection_flag_bits_e;
122 typedef enum _tcp_connection_flag
124 #define _(sym, str) TCP_CONN_##sym = 1 << TCP_CONN_##sym##_BIT,
125 foreach_tcp_connection_flag
128 } tcp_connection_flags_e;
130 /** TCP buffer flags */
131 #define foreach_tcp_buf_flag \
132 _ (ACK) /**< Sending ACK. */ \
133 _ (DUPACK) /**< Sending DUPACK. */ \
137 #define _(f) TCP_BUF_BIT_##f,
145 #define _(f) TCP_BUF_FLAG_##f = 1 << TCP_BUF_BIT_##f,
150 #define TCP_MAX_SACK_BLOCKS 5 /**< Max number of SACK blocks stored */
151 #define TCP_INVALID_SACK_HOLE_INDEX ((u32)~0)
153 typedef struct _sack_scoreboard_hole
155 u32 next; /**< Index for next entry in linked list */
156 u32 prev; /**< Index for previous entry in linked list */
157 u32 start; /**< Start sequence number */
158 u32 end; /**< End sequence number */
159 } sack_scoreboard_hole_t;
161 typedef struct _sack_scoreboard
163 sack_scoreboard_hole_t *holes; /**< Pool of holes */
164 u32 head; /**< Index of first entry */
165 u32 tail; /**< Index of last entry */
166 u32 sacked_bytes; /**< Number of bytes sacked in sb */
167 u32 last_sacked_bytes; /**< Number of bytes last sacked */
168 u32 snd_una_adv; /**< Bytes to add to snd_una */
169 u32 max_byte_sacked; /**< Highest byte acked */
172 typedef enum _tcp_cc_algorithm_type
175 } tcp_cc_algorithm_type_e;
177 typedef struct _tcp_cc_algorithm tcp_cc_algorithm_t;
179 typedef enum _tcp_cc_ack_t
186 typedef struct _tcp_connection
188 transport_connection_t connection; /**< Common transport data. First! */
190 u8 state; /**< TCP state as per tcp_state_t */
191 u16 flags; /**< Connection flags (see tcp_conn_flags_e) */
192 u32 timers[TCP_N_TIMERS]; /**< Timer handles into timer wheel */
196 /** Send sequence variables RFC793 */
197 u32 snd_una; /**< oldest unacknowledged sequence number */
198 u32 snd_una_max; /**< newest unacknowledged sequence number + 1*/
199 u32 snd_wnd; /**< send window */
200 u32 snd_wl1; /**< seq number used for last snd.wnd update */
201 u32 snd_wl2; /**< ack number used for last snd.wnd update */
202 u32 snd_nxt; /**< next seq number to be sent */
204 /** Receive sequence variables RFC793 */
205 u32 rcv_nxt; /**< next sequence number expected */
206 u32 rcv_wnd; /**< receive window we expect */
208 u32 rcv_las; /**< rcv_nxt at last ack sent/rcv_wnd update */
209 u32 iss; /**< initial sent sequence */
210 u32 irs; /**< initial remote sequence */
213 tcp_options_t opt; /**< TCP connection options parsed */
214 u8 rcv_wscale; /**< Window scale to advertise to peer */
215 u8 snd_wscale; /**< Window scale to use when sending */
216 u32 tsval_recent; /**< Last timestamp received */
217 u32 tsval_recent_age; /**< When last updated tstamp_recent*/
219 sack_block_t *snd_sacks; /**< Vector of SACKs to send. XXX Fixed size? */
220 sack_scoreboard_t sack_sb; /**< SACK "scoreboard" that tracks holes */
222 u16 rcv_dupacks; /**< Number of DUPACKs received */
223 u8 snt_dupacks; /**< Number of DUPACKs sent in a burst */
225 /* Congestion control */
226 u32 cwnd; /**< Congestion window */
227 u32 ssthresh; /**< Slow-start threshold */
228 u32 prev_ssthresh; /**< ssthresh before congestion */
229 u32 bytes_acked; /**< Bytes acknowledged by current segment */
230 u32 rtx_bytes; /**< Retransmitted bytes */
231 u32 tsecr_last_ack; /**< Timestamp echoed to us in last healthy ACK */
232 u32 snd_congestion; /**< snd_una_max when congestion is detected */
233 tcp_cc_algorithm_t *cc_algo; /**< Congestion control algorithm */
236 u32 rto; /**< Retransmission timeout */
237 u32 rto_boff; /**< Index for RTO backoff */
238 u32 srtt; /**< Smoothed RTT */
239 u32 rttvar; /**< Smoothed mean RTT difference. Approximates variance */
240 u32 rtt_ts; /**< Timestamp for tracked ACK */
241 u32 rtt_seq; /**< Sequence number for tracked ACK */
243 u16 snd_mss; /**< Send MSS */
246 struct _tcp_cc_algorithm
248 void (*rcv_ack) (tcp_connection_t * tc);
249 void (*rcv_cong_ack) (tcp_connection_t * tc, tcp_cc_ack_t ack);
250 void (*congestion) (tcp_connection_t * tc);
251 void (*recovered) (tcp_connection_t * tc);
252 void (*init) (tcp_connection_t * tc);
255 #define tcp_fastrecovery_on(tc) (tc)->flags |= TCP_CONN_FAST_RECOVERY
256 #define tcp_fastrecovery_off(tc) (tc)->flags &= ~TCP_CONN_FAST_RECOVERY
257 #define tcp_recovery_on(tc) (tc)->flags |= TCP_CONN_RECOVERY
258 #define tcp_recovery_off(tc) (tc)->flags &= ~TCP_CONN_RECOVERY
259 #define tcp_in_fastrecovery(tc) ((tc)->flags & TCP_CONN_FAST_RECOVERY)
260 #define tcp_in_recovery(tc) ((tc)->flags & (TCP_CONN_RECOVERY))
261 #define tcp_in_slowstart(tc) (tc->cwnd < tc->ssthresh)
262 #define tcp_fastrecovery_sent_1_smss(tc) ((tc)->flags & TCP_CONN_FR_1_SMSS)
263 #define tcp_fastrecovery_1_smss_on(tc) ((tc)->flags |= TCP_CONN_FR_1_SMSS)
264 #define tcp_fastrecovery_1_smss_off(tc) ((tc)->flags &= ~TCP_CONN_FR_1_SMSS)
266 #define tcp_in_cong_recovery(tc) ((tc)->flags & \
267 (TCP_CONN_FAST_RECOVERY | TCP_CONN_RECOVERY))
270 tcp_cong_recovery_off (tcp_connection_t * tc)
272 tc->flags &= ~(TCP_CONN_FAST_RECOVERY | TCP_CONN_RECOVERY);
273 tcp_fastrecovery_1_smss_off (tc);
283 typedef enum _tcp_error
285 #define tcp_error(n,s) TCP_ERROR_##n,
286 #include <vnet/tcp/tcp_error.def>
291 typedef struct _tcp_lookup_dispatch
294 } tcp_lookup_dispatch_t;
296 typedef struct _tcp_main
298 /* Per-worker thread tcp connection pools */
299 tcp_connection_t **connections;
301 /* Pool of listeners. */
302 tcp_connection_t *listener_pool;
304 /** Dispatch table by state and flags */
305 tcp_lookup_dispatch_t dispatch_table[TCP_N_STATES][64];
307 u8 log2_tstamp_clocks_per_tick;
308 f64 tstamp_ticks_per_clock;
310 /** per-worker tx buffer free lists */
313 /* Per worker-thread timer wheel for connections timers */
314 tw_timer_wheel_16t_2w_512sl_t *timer_wheels;
316 // /* Convenience per worker-thread vector of connections to DELACK */
317 // u32 **delack_connections;
319 /* Pool of half-open connections on which we've sent a SYN */
320 tcp_connection_t *half_open_connections;
322 /* Pool of local TCP endpoints */
323 transport_endpoint_t *local_endpoints;
325 /* Local endpoints lookup table */
326 transport_endpoint_table_t local_endpoints_table;
328 /* Congestion control algorithms registered */
329 tcp_cc_algorithm_t *cc_algos;
331 /* Flag that indicates if stack is on or off */
335 vlib_main_t *vlib_main;
336 vnet_main_t *vnet_main;
337 ip4_main_t *ip4_main;
338 ip6_main_t *ip6_main;
341 extern tcp_main_t tcp_main;
342 extern vlib_node_registration_t tcp4_input_node;
343 extern vlib_node_registration_t tcp6_input_node;
344 extern vlib_node_registration_t tcp4_output_node;
345 extern vlib_node_registration_t tcp6_output_node;
347 always_inline tcp_main_t *
353 clib_error_t *vnet_tcp_enable_disable (vlib_main_t * vm, u8 is_en);
355 always_inline tcp_connection_t *
356 tcp_connection_get (u32 conn_index, u32 thread_index)
358 if (pool_is_free_index (tcp_main.connections[thread_index], conn_index))
360 return pool_elt_at_index (tcp_main.connections[thread_index], conn_index);
363 always_inline tcp_connection_t *
364 tcp_connection_get_if_valid (u32 conn_index, u32 thread_index)
366 if (tcp_main.connections[thread_index] == 0)
368 if (pool_is_free_index (tcp_main.connections[thread_index], conn_index))
370 return pool_elt_at_index (tcp_main.connections[thread_index], conn_index);
373 void tcp_connection_close (tcp_connection_t * tc);
374 void tcp_connection_cleanup (tcp_connection_t * tc);
375 void tcp_connection_del (tcp_connection_t * tc);
376 void tcp_connection_reset (tcp_connection_t * tc);
378 u8 *format_tcp_connection (u8 * s, va_list * args);
379 u8 *format_tcp_connection_verbose (u8 * s, va_list * args);
381 always_inline tcp_connection_t *
382 tcp_listener_get (u32 tli)
384 return pool_elt_at_index (tcp_main.listener_pool, tli);
387 always_inline tcp_connection_t *
388 tcp_half_open_connection_get (u32 conn_index)
390 return pool_elt_at_index (tcp_main.half_open_connections, conn_index);
393 void tcp_make_ack (tcp_connection_t * ts, vlib_buffer_t * b);
394 void tcp_make_fin (tcp_connection_t * tc, vlib_buffer_t * b);
395 void tcp_make_synack (tcp_connection_t * ts, vlib_buffer_t * b);
396 void tcp_send_reset (vlib_buffer_t * pkt, u8 is_ip4);
397 void tcp_send_syn (tcp_connection_t * tc);
398 void tcp_send_fin (tcp_connection_t * tc);
399 void tcp_set_snd_mss (tcp_connection_t * tc);
402 tcp_end_seq (tcp_header_t * th, u32 len)
404 return th->seq_number + tcp_is_syn (th) + tcp_is_fin (th) + len;
407 /* Modulo arithmetic for TCP sequence numbers */
408 #define seq_lt(_s1, _s2) ((i32)((_s1)-(_s2)) < 0)
409 #define seq_leq(_s1, _s2) ((i32)((_s1)-(_s2)) <= 0)
410 #define seq_gt(_s1, _s2) ((i32)((_s1)-(_s2)) > 0)
411 #define seq_geq(_s1, _s2) ((i32)((_s1)-(_s2)) >= 0)
413 /* Modulo arithmetic for timestamps */
414 #define timestamp_lt(_t1, _t2) ((i32)((_t1)-(_t2)) < 0)
415 #define timestamp_leq(_t1, _t2) ((i32)((_t1)-(_t2)) <= 0)
418 tcp_flight_size (const tcp_connection_t * tc)
422 flight_size = (int) ((tc->snd_una_max - tc->snd_una) + tc->rtx_bytes)
423 - (tc->rcv_dupacks * tc->snd_mss) /* - tc->sack_sb.sacked_bytes */ ;
425 /* Happens if we don't clear sacked bytes */
433 * Initial cwnd as per RFC5681
436 tcp_initial_cwnd (const tcp_connection_t * tc)
438 if (tc->snd_mss > 2190)
439 return 2 * tc->snd_mss;
440 else if (tc->snd_mss > 1095)
441 return 3 * tc->snd_mss;
443 return 4 * tc->snd_mss;
447 tcp_loss_wnd (const tcp_connection_t * tc)
453 tcp_available_wnd (const tcp_connection_t * tc)
455 return clib_min (tc->cwnd, tc->snd_wnd);
459 tcp_available_snd_space (const tcp_connection_t * tc)
461 u32 available_wnd = tcp_available_wnd (tc);
462 u32 flight_size = tcp_flight_size (tc);
464 if (available_wnd <= flight_size)
467 return available_wnd - flight_size;
470 void tcp_update_rcv_wnd (tcp_connection_t * tc);
472 void tcp_retransmit_first_unacked (tcp_connection_t * tc);
474 void tcp_fast_retransmit (tcp_connection_t * tc);
475 void tcp_cc_congestion (tcp_connection_t * tc);
476 void tcp_cc_recover (tcp_connection_t * tc);
481 return clib_cpu_time_now () * tcp_main.tstamp_ticks_per_clock;
484 u32 tcp_push_header (transport_connection_t * tconn, vlib_buffer_t * b);
487 tcp_prepare_retransmit_segment (tcp_connection_t * tc, vlib_buffer_t * b,
488 u32 offset, u32 max_bytes);
490 void tcp_connection_timers_init (tcp_connection_t * tc);
491 void tcp_connection_timers_reset (tcp_connection_t * tc);
493 void tcp_connection_init_vars (tcp_connection_t * tc);
496 tcp_connection_force_ack (tcp_connection_t * tc, vlib_buffer_t * b)
498 /* Reset flags, make sure ack is sent */
499 tc->flags = TCP_CONN_SNDACK;
500 vnet_buffer (b)->tcp.flags &= ~TCP_BUF_FLAG_DUPACK;
504 tcp_timer_set (tcp_connection_t * tc, u8 timer_id, u32 interval)
507 = tw_timer_start_16t_2w_512sl (&tcp_main.timer_wheels[tc->c_thread_index],
508 tc->c_c_index, timer_id, interval);
512 tcp_timer_reset (tcp_connection_t * tc, u8 timer_id)
514 if (tc->timers[timer_id] == TCP_TIMER_HANDLE_INVALID)
517 tw_timer_stop_16t_2w_512sl (&tcp_main.timer_wheels[tc->c_thread_index],
518 tc->timers[timer_id]);
519 tc->timers[timer_id] = TCP_TIMER_HANDLE_INVALID;
523 tcp_timer_update (tcp_connection_t * tc, u8 timer_id, u32 interval)
525 if (tc->timers[timer_id] != TCP_TIMER_HANDLE_INVALID)
526 tw_timer_stop_16t_2w_512sl (&tcp_main.timer_wheels[tc->c_thread_index],
527 tc->timers[timer_id]);
528 tc->timers[timer_id] =
529 tw_timer_start_16t_2w_512sl (&tcp_main.timer_wheels[tc->c_thread_index],
530 tc->c_c_index, timer_id, interval);
533 /* XXX Switch retransmit to faster TW */
535 tcp_retransmit_timer_set (tcp_connection_t * tc)
537 tcp_timer_set (tc, TCP_TIMER_RETRANSMIT,
538 clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
542 tcp_retransmit_timer_update (tcp_connection_t * tc)
544 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT,
545 clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
549 tcp_retransmit_timer_reset (tcp_connection_t * tc)
551 tcp_timer_reset (tc, TCP_TIMER_RETRANSMIT);
555 tcp_persist_timer_set (tcp_connection_t * tc)
557 /* Reuse RTO. It's backed off in handler */
558 tcp_timer_set (tc, TCP_TIMER_PERSIST,
559 clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
563 tcp_persist_timer_update (tcp_connection_t * tc)
565 tcp_timer_update (tc, TCP_TIMER_PERSIST,
566 clib_max (tc->rto * TCP_TO_TIMER_TICK, 1));
570 tcp_persist_timer_reset (tcp_connection_t * tc)
572 tcp_timer_reset (tc, TCP_TIMER_PERSIST);
576 tcp_timer_is_active (tcp_connection_t * tc, tcp_timers_e timer)
578 return tc->timers[timer] != TCP_TIMER_HANDLE_INVALID;
582 scoreboard_remove_hole (sack_scoreboard_t * sb,
583 sack_scoreboard_hole_t * hole);
585 always_inline sack_scoreboard_hole_t *
586 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
588 if (index != TCP_INVALID_SACK_HOLE_INDEX)
589 return pool_elt_at_index (sb->holes, index);
593 always_inline sack_scoreboard_hole_t *
594 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
596 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
597 return pool_elt_at_index (sb->holes, hole->next);
601 always_inline sack_scoreboard_hole_t *
602 scoreboard_first_hole (sack_scoreboard_t * sb)
604 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
605 return pool_elt_at_index (sb->holes, sb->head);
609 always_inline sack_scoreboard_hole_t *
610 scoreboard_last_hole (sack_scoreboard_t * sb)
612 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
613 return pool_elt_at_index (sb->holes, sb->tail);
618 scoreboard_clear (sack_scoreboard_t * sb)
620 sack_scoreboard_hole_t *hole = scoreboard_first_hole (sb);
621 while ((hole = scoreboard_first_hole (sb)))
623 scoreboard_remove_hole (sb, hole);
625 sb->sacked_bytes = 0;
626 sb->last_sacked_bytes = 0;
628 sb->max_byte_sacked = 0;
632 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
634 return hole->end - hole->start;
638 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
640 return hole - sb->holes;
644 scoreboard_init (sack_scoreboard_t * sb)
646 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
647 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
650 void tcp_rcv_sacks (tcp_connection_t * tc, u32 ack);
653 tcp_cc_algo_register (tcp_cc_algorithm_type_e type,
654 const tcp_cc_algorithm_t * vft)
656 tcp_main_t *tm = vnet_get_tcp_main ();
657 vec_validate (tm->cc_algos, type);
659 tm->cc_algos[type] = *vft;
662 always_inline tcp_cc_algorithm_t *
663 tcp_cc_algo_get (tcp_cc_algorithm_type_e type)
665 tcp_main_t *tm = vnet_get_tcp_main ();
666 return &tm->cc_algos[type];
669 void tcp_cc_init (tcp_connection_t * tc);
672 * Push TCP header to buffer
674 * @param vm - vlib_main
675 * @param b - buffer to write the header to
676 * @param sp_net - source port net order
677 * @param dp_net - destination port net order
678 * @param seq - sequence number net order
679 * @param ack - ack number net order
680 * @param tcp_hdr_opts_len - header and options length in bytes
681 * @param flags - header flags
682 * @param wnd - window size
684 * @return - pointer to start of TCP header
687 vlib_buffer_push_tcp_net_order (vlib_buffer_t * b, u16 sp, u16 dp, u32 seq,
688 u32 ack, u8 tcp_hdr_opts_len, u8 flags,
693 th = vlib_buffer_push_uninit (b, tcp_hdr_opts_len);
697 th->seq_number = seq;
698 th->ack_number = ack;
699 th->data_offset_and_reserved = (tcp_hdr_opts_len >> 2) << 4;
703 th->urgent_pointer = 0;
708 * Push TCP header to buffer
710 * @param b - buffer to write the header to
711 * @param sp_net - source port net order
712 * @param dp_net - destination port net order
713 * @param seq - sequence number host order
714 * @param ack - ack number host order
715 * @param tcp_hdr_opts_len - header and options length in bytes
716 * @param flags - header flags
717 * @param wnd - window size
719 * @return - pointer to start of TCP header
722 vlib_buffer_push_tcp (vlib_buffer_t * b, u16 sp_net, u16 dp_net, u32 seq,
723 u32 ack, u8 tcp_hdr_opts_len, u8 flags, u16 wnd)
725 return vlib_buffer_push_tcp_net_order (b, sp_net, dp_net,
726 clib_host_to_net_u32 (seq),
727 clib_host_to_net_u32 (ack),
728 tcp_hdr_opts_len, flags,
729 clib_host_to_net_u16 (wnd));
732 #endif /* _vnet_tcp_h_ */
735 * fd.io coding-style-patch-verification: ON
738 * eval: (c-set-style "gnu")