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.
16 #include <vppinfra/sparse_vec.h>
17 #include <vnet/tcp/tcp_packet.h>
18 #include <vnet/tcp/tcp.h>
19 #include <vnet/session/session.h>
22 static char *tcp_error_strings[] = {
23 #define tcp_error(n,s) s,
24 #include <vnet/tcp/tcp_error.def>
28 /* All TCP nodes have the same outgoing arcs */
29 #define foreach_tcp_state_next \
30 _ (DROP4, "ip4-drop") \
31 _ (DROP6, "ip6-drop") \
32 _ (TCP4_OUTPUT, "tcp4-output") \
33 _ (TCP6_OUTPUT, "tcp6-output")
35 typedef enum _tcp_established_next
37 #define _(s,n) TCP_ESTABLISHED_NEXT_##s,
38 foreach_tcp_state_next
40 TCP_ESTABLISHED_N_NEXT,
41 } tcp_established_next_t;
43 typedef enum _tcp_rcv_process_next
45 #define _(s,n) TCP_RCV_PROCESS_NEXT_##s,
46 foreach_tcp_state_next
48 TCP_RCV_PROCESS_N_NEXT,
49 } tcp_rcv_process_next_t;
51 typedef enum _tcp_syn_sent_next
53 #define _(s,n) TCP_SYN_SENT_NEXT_##s,
54 foreach_tcp_state_next
57 } tcp_syn_sent_next_t;
59 typedef enum _tcp_listen_next
61 #define _(s,n) TCP_LISTEN_NEXT_##s,
62 foreach_tcp_state_next
67 /* Generic, state independent indices */
68 typedef enum _tcp_state_next
70 #define _(s,n) TCP_NEXT_##s,
71 foreach_tcp_state_next
76 #define tcp_next_output(is_ip4) (is_ip4 ? TCP_NEXT_TCP4_OUTPUT \
77 : TCP_NEXT_TCP6_OUTPUT)
79 #define tcp_next_drop(is_ip4) (is_ip4 ? TCP_NEXT_DROP4 \
83 * Validate segment sequence number. As per RFC793:
85 * Segment Receive Test
87 * ------- ------- -------------------------------------------
88 * 0 0 SEG.SEQ = RCV.NXT
89 * 0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
91 * >0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
92 * or RCV.NXT =< SEG.SEQ+SEG.LEN-1 < RCV.NXT+RCV.WND
94 * This ultimately consists in checking if segment falls within the window.
95 * The one important difference compared to RFC793 is that we use rcv_las,
96 * or the rcv_nxt at last ack sent instead of rcv_nxt since that's the
97 * peer's reference when computing our receive window.
100 * seq_leq (end_seq, tc->rcv_las + tc->rcv_wnd) && seq_geq (seq, tc->rcv_las)
101 * however, is too strict when we have retransmits. Instead we just check that
102 * the seq is not beyond the right edge and that the end of the segment is not
103 * less than the left edge.
105 * N.B. rcv_nxt and rcv_wnd are both updated in this node if acks are sent, so
106 * use rcv_nxt in the right edge window test instead of rcv_las.
110 tcp_segment_in_rcv_wnd (tcp_connection_t * tc, u32 seq, u32 end_seq)
112 return (seq_geq (end_seq, tc->rcv_las)
113 && seq_leq (seq, tc->rcv_nxt + tc->rcv_wnd));
117 * Parse TCP header options.
119 * @param th TCP header
120 * @param to TCP options data structure to be populated
121 * @param is_syn set if packet is syn
122 * @return -1 if parsing failed
125 tcp_options_parse (tcp_header_t * th, tcp_options_t * to, u8 is_syn)
128 u8 opt_len, opts_len, kind;
132 opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t);
133 data = (const u8 *) (th + 1);
135 /* Zero out all flags but those set in SYN */
136 to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE
137 | TCP_OPTS_FLAG_TSTAMP | TCP_OPTION_MSS);
139 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
143 /* Get options length */
144 if (kind == TCP_OPTION_EOL)
146 else if (kind == TCP_OPTION_NOOP)
158 /* weird option length */
159 if (opt_len < 2 || opt_len > opts_len)
169 if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
171 to->flags |= TCP_OPTS_FLAG_MSS;
172 to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
175 case TCP_OPTION_WINDOW_SCALE:
178 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
180 to->flags |= TCP_OPTS_FLAG_WSCALE;
181 to->wscale = data[2];
182 if (to->wscale > TCP_MAX_WND_SCALE)
183 to->wscale = TCP_MAX_WND_SCALE;
186 case TCP_OPTION_TIMESTAMP:
188 to->flags |= TCP_OPTS_FLAG_TSTAMP;
189 if ((to->flags & TCP_OPTS_FLAG_TSTAMP)
190 && opt_len == TCP_OPTION_LEN_TIMESTAMP)
192 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
193 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
196 case TCP_OPTION_SACK_PERMITTED:
199 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
200 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
202 case TCP_OPTION_SACK_BLOCK:
203 /* If SACK permitted was not advertised or a SYN, break */
204 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
207 /* If too short or not correctly formatted, break */
208 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
211 to->flags |= TCP_OPTS_FLAG_SACK;
212 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
213 vec_reset_length (to->sacks);
214 for (j = 0; j < to->n_sack_blocks; j++)
216 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 8 * j));
217 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 8 * j));
218 vec_add1 (to->sacks, b);
222 /* Nothing to see here */
230 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
231 * timestamp to echo and it's less than tsval_recent, drop segment
232 * but still send an ACK in order to retain TCP's mechanism for detecting
233 * and recovering from half-open connections
235 * Or at least that's what the theory says. It seems that this might not work
236 * very well with packet reordering and fast retransmit. XXX
239 tcp_segment_check_paws (tcp_connection_t * tc)
241 return tcp_opts_tstamp (&tc->rcv_opts)
242 && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent);
246 * Update tsval recent
249 tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
252 * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
253 * of an incoming segment:
254 * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
255 * then the TSval from the segment is copied to TS.Recent;
256 * otherwise, the TSval is ignored.
258 if (tcp_opts_tstamp (&tc->rcv_opts) && seq_leq (seq, tc->rcv_las)
259 && seq_leq (tc->rcv_las, seq_end))
261 ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval));
262 tc->tsval_recent = tc->rcv_opts.tsval;
263 tc->tsval_recent_age = tcp_time_now_w_thread (tc->c_thread_index);
268 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
270 * It first verifies if segment has a wrapped sequence number (PAWS) and then
271 * does the processing associated to the first four steps (ignoring security
272 * and precedence): sequence number, rst bit and syn bit checks.
274 * @return 0 if segments passes validation.
277 tcp_segment_validate (tcp_worker_ctx_t * wrk, tcp_connection_t * tc0,
278 vlib_buffer_t * b0, tcp_header_t * th0, u32 * error0)
280 /* We could get a burst of RSTs interleaved with acks */
281 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
283 tcp_send_reset (tc0);
284 *error0 = TCP_ERROR_CONNECTION_CLOSED;
288 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
290 *error0 = TCP_ERROR_SEGMENT_INVALID;
294 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts, 0)))
296 *error0 = TCP_ERROR_OPTIONS;
300 if (PREDICT_FALSE (tcp_segment_check_paws (tc0)))
302 *error0 = TCP_ERROR_PAWS;
303 TCP_EVT_DBG (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
304 vnet_buffer (b0)->tcp.seq_end);
306 /* If it just so happens that a segment updates tsval_recent for a
307 * segment over 24 days old, invalidate tsval_recent. */
308 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
309 tcp_time_now_w_thread (tc0->c_thread_index)))
311 tc0->tsval_recent = tc0->rcv_opts.tsval;
312 clib_warning ("paws failed: 24-day old segment");
314 /* Drop after ack if not rst. Resets can fail paws check as per
315 * RFC 7323 sec. 5.2: When an <RST> segment is received, it MUST NOT
316 * be subjected to the PAWS check by verifying an acceptable value in
318 else if (!tcp_rst (th0))
320 tcp_program_ack (wrk, tc0);
321 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
326 /* 1st: check sequence number */
327 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
328 vnet_buffer (b0)->tcp.seq_end))
330 /* SYN/SYN-ACK retransmit */
332 && vnet_buffer (b0)->tcp.seq_number == tc0->rcv_nxt - 1)
334 tcp_options_parse (th0, &tc0->rcv_opts, 1);
335 if (tc0->state == TCP_STATE_SYN_RCVD)
337 tcp_send_synack (tc0);
338 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0, 0);
339 *error0 = TCP_ERROR_SYNS_RCVD;
343 tcp_program_ack (wrk, tc0);
344 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, tc0);
345 *error0 = TCP_ERROR_SYN_ACKS_RCVD;
350 /* If our window is 0 and the packet is in sequence, let it pass
351 * through for ack processing. It should be dropped later. */
352 if (tc0->rcv_wnd < tc0->snd_mss
353 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number)
356 /* If we entered recovery and peer did so as well, there's a chance that
357 * dup acks won't be acceptable on either end because seq_end may be less
358 * than rcv_las. This can happen if acks are lost in both directions. */
359 if (tcp_in_recovery (tc0)
360 && seq_geq (vnet_buffer (b0)->tcp.seq_number,
361 tc0->rcv_las - tc0->rcv_wnd)
362 && seq_leq (vnet_buffer (b0)->tcp.seq_end,
363 tc0->rcv_nxt + tc0->rcv_wnd))
366 *error0 = TCP_ERROR_RCV_WND;
368 /* If not RST, send dup ack */
371 tcp_program_dupack (wrk, tc0);
372 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
380 /* 2nd: check the RST bit */
381 if (PREDICT_FALSE (tcp_rst (th0)))
383 tcp_connection_reset (tc0);
384 *error0 = TCP_ERROR_RST_RCVD;
388 /* 3rd: check security and precedence (skip) */
390 /* 4th: check the SYN bit (in window) */
391 if (PREDICT_FALSE (tcp_syn (th0)))
393 /* As per RFC5961 send challenge ack instead of reset */
394 tcp_program_ack (wrk, tc0);
395 *error0 = TCP_ERROR_SPURIOUS_SYN;
399 /* If segment in window, save timestamp */
400 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
401 vnet_buffer (b0)->tcp.seq_end);
409 tcp_rcv_ack_no_cc (tcp_connection_t * tc, vlib_buffer_t * b, u32 * error)
411 /* SND.UNA =< SEG.ACK =< SND.NXT */
412 if (!(seq_leq (tc->snd_una, vnet_buffer (b)->tcp.ack_number)
413 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
415 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)
416 && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
418 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
421 *error = TCP_ERROR_ACK_INVALID;
426 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
427 tc->snd_una = vnet_buffer (b)->tcp.ack_number;
428 *error = TCP_ERROR_ACK_OK;
433 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
435 * Note that although the original article, srtt and rttvar are scaled
436 * to minimize round-off errors, here we don't. Instead, we rely on
437 * better precision time measurements.
439 * TODO support us rtt resolution
442 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
448 err = mrtt - tc->srtt;
450 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
451 * The increase should be bound */
452 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
453 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
454 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
458 /* First measurement. */
460 tc->rttvar = mrtt >> 1;
464 #ifndef CLIB_MARCH_VARIANT
466 tcp_update_rto (tcp_connection_t * tc)
468 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
469 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
471 #endif /* CLIB_MARCH_VARIANT */
474 * Update RTT estimate and RTO timer
476 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
477 * timing. Middle boxes are known to fiddle with TCP options so we
478 * should give higher priority to ACK timing.
480 * This should be called only if previously sent bytes have been acked.
482 * return 1 if valid rtt 0 otherwise
485 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
489 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
490 * RTT because they're ambiguous. */
491 if (tcp_in_cong_recovery (tc) || tc->sack_sb.sacked_bytes)
493 if (tcp_in_recovery (tc))
498 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
500 f64 sample = tcp_time_now_us (tc->c_thread_index) - tc->rtt_ts;
501 tc->mrtt_us = tc->mrtt_us + (sample - tc->mrtt_us) * 0.125;
502 mrtt = clib_max ((u32) (sample * THZ), 1);
503 /* Allow measuring of a new RTT */
506 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
507 * snd_una, i.e., the left side of the send window:
508 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
509 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
511 u32 now = tcp_tstamp (tc);
512 mrtt = clib_max (now - tc->rcv_opts.tsecr, 1);
515 /* Ignore dubious measurements */
516 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
519 tcp_estimate_rtt (tc, mrtt);
523 /* If we got here something must've been ACKed so make sure boff is 0,
524 * even if mrtt is not valid since we update the rto lower */
532 tcp_estimate_initial_rtt (tcp_connection_t * tc)
534 u8 thread_index = vlib_num_workers ()? 1 : 0;
539 tc->mrtt_us = tcp_time_now_us (thread_index) - tc->rtt_ts;
540 tc->mrtt_us = clib_max (tc->mrtt_us, 0.0001);
541 mrtt = clib_max ((u32) (tc->mrtt_us * THZ), 1);
546 mrtt = tcp_time_now_w_thread (thread_index) - tc->rcv_opts.tsecr;
547 mrtt = clib_max (mrtt, 1);
548 /* Due to retransmits we don't know the initial mrtt */
549 if (tc->rto_boff && mrtt > 1 * THZ)
551 tc->mrtt_us = (f64) mrtt *TCP_TICK;
554 if (mrtt > 0 && mrtt < TCP_RTT_MAX)
555 tcp_estimate_rtt (tc, mrtt);
560 * Dequeue bytes for connections that have received acks in last burst
563 tcp_handle_postponed_dequeues (tcp_worker_ctx_t * wrk)
565 u32 thread_index = wrk->vm->thread_index;
566 u32 *pending_deq_acked;
567 tcp_connection_t *tc;
570 if (!vec_len (wrk->pending_deq_acked))
573 pending_deq_acked = wrk->pending_deq_acked;
574 for (i = 0; i < vec_len (pending_deq_acked); i++)
576 tc = tcp_connection_get (pending_deq_acked[i], thread_index);
577 tc->flags &= ~TCP_CONN_DEQ_PENDING;
579 if (PREDICT_FALSE (!tc->burst_acked))
582 /* Dequeue the newly ACKed bytes */
583 session_tx_fifo_dequeue_drop (&tc->connection, tc->burst_acked);
585 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
587 if (PREDICT_FALSE (tc->flags & TCP_CONN_PSH_PENDING))
589 if (seq_leq (tc->psh_seq, tc->snd_una))
590 tc->flags &= ~TCP_CONN_PSH_PENDING;
593 /* If everything has been acked, stop retransmit timer
594 * otherwise update. */
595 tcp_retransmit_timer_update (tc);
597 /* If not congested, update pacer based on our new
599 if (!tcp_in_fastrecovery (tc))
600 tcp_connection_tx_pacer_update (tc);
602 _vec_len (wrk->pending_deq_acked) = 0;
606 tcp_program_dequeue (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
608 if (!(tc->flags & TCP_CONN_DEQ_PENDING))
610 vec_add1 (wrk->pending_deq_acked, tc->c_c_index);
611 tc->flags |= TCP_CONN_DEQ_PENDING;
613 tc->burst_acked += tc->bytes_acked + tc->sack_sb.snd_una_adv;
617 * Check if duplicate ack as per RFC5681 Sec. 2
620 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
623 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
624 && seq_gt (tc->snd_nxt, tc->snd_una)
625 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
626 && (prev_snd_wnd == tc->snd_wnd));
630 * Checks if ack is a congestion control event.
633 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
634 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
636 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
637 * defined to be 'duplicate' */
638 *is_dack = tc->sack_sb.last_sacked_bytes
639 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
641 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
644 #ifndef CLIB_MARCH_VARIANT
646 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
648 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
649 return hole - sb->holes;
653 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
655 return hole->end - hole->start;
658 sack_scoreboard_hole_t *
659 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
661 if (index != TCP_INVALID_SACK_HOLE_INDEX)
662 return pool_elt_at_index (sb->holes, index);
666 sack_scoreboard_hole_t *
667 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
669 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
670 return pool_elt_at_index (sb->holes, hole->next);
674 sack_scoreboard_hole_t *
675 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
677 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
678 return pool_elt_at_index (sb->holes, hole->prev);
682 sack_scoreboard_hole_t *
683 scoreboard_first_hole (sack_scoreboard_t * sb)
685 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
686 return pool_elt_at_index (sb->holes, sb->head);
690 sack_scoreboard_hole_t *
691 scoreboard_last_hole (sack_scoreboard_t * sb)
693 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
694 return pool_elt_at_index (sb->holes, sb->tail);
699 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
701 sack_scoreboard_hole_t *next, *prev;
703 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
705 next = pool_elt_at_index (sb->holes, hole->next);
706 next->prev = hole->prev;
710 sb->tail = hole->prev;
713 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
715 prev = pool_elt_at_index (sb->holes, hole->prev);
716 prev->next = hole->next;
720 sb->head = hole->next;
723 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
724 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
726 /* Poison the entry */
728 clib_memset (hole, 0xfe, sizeof (*hole));
730 pool_put (sb->holes, hole);
733 static sack_scoreboard_hole_t *
734 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
737 sack_scoreboard_hole_t *hole, *next, *prev;
740 pool_get (sb->holes, hole);
741 clib_memset (hole, 0, sizeof (*hole));
745 hole_index = scoreboard_hole_index (sb, hole);
747 prev = scoreboard_get_hole (sb, prev_index);
750 hole->prev = prev_index;
751 hole->next = prev->next;
753 if ((next = scoreboard_next_hole (sb, hole)))
754 next->prev = hole_index;
756 sb->tail = hole_index;
758 prev->next = hole_index;
762 sb->head = hole_index;
763 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
764 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
769 #endif /* CLIB_MARCH_VARIANT */
771 #ifndef CLIB_MARCH_VARIANT
773 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
775 sack_scoreboard_hole_t *left, *right;
776 u32 bytes = 0, blks = 0;
778 sb->last_lost_bytes = 0;
780 sb->sacked_bytes = 0;
781 left = scoreboard_last_hole (sb);
785 if (seq_gt (sb->high_sacked, left->end))
787 bytes = sb->high_sacked - left->end;
791 while ((right = left)
792 && bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
793 && blks < TCP_DUPACK_THRESHOLD
794 /* left not updated if above conditions fail */
795 && (left = scoreboard_prev_hole (sb, right)))
797 bytes += right->start - left->end;
801 /* left is first lost */
806 sb->lost_bytes += scoreboard_hole_bytes (right);
807 sb->last_lost_bytes += left->is_lost ? 0 : left->end - left->start;
809 left = scoreboard_prev_hole (sb, right);
811 bytes += right->start - left->end;
813 while ((right = left));
816 sb->sacked_bytes = bytes;
820 * Figure out the next hole to retransmit
822 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
824 sack_scoreboard_hole_t *
825 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
826 sack_scoreboard_hole_t * start,
827 u8 have_unsent, u8 * can_rescue, u8 * snd_limited)
829 sack_scoreboard_hole_t *hole = 0;
831 hole = start ? start : scoreboard_first_hole (sb);
832 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
833 hole = scoreboard_next_hole (sb, hole);
835 /* Nothing, return */
838 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
842 /* Rule (1): if higher than rxt, less than high_sacked and lost */
843 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
845 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
849 /* Rule (2): available unsent data */
852 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
855 /* Rule (3): if hole not lost */
856 else if (seq_lt (hole->start, sb->high_sacked))
859 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
861 /* Rule (4): if hole beyond high_sacked */
864 ASSERT (seq_geq (hole->start, sb->high_sacked));
867 /* HighRxt MUST NOT be updated */
872 if (hole && seq_lt (sb->high_rxt, hole->start))
873 sb->high_rxt = hole->start;
877 #endif /* CLIB_MARCH_VARIANT */
880 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 snd_una)
882 sack_scoreboard_hole_t *hole;
883 hole = scoreboard_first_hole (sb);
886 snd_una = seq_gt (snd_una, hole->start) ? snd_una : hole->start;
887 sb->cur_rxt_hole = sb->head;
889 sb->high_rxt = snd_una;
890 sb->rescue_rxt = snd_una - 1;
893 #ifndef CLIB_MARCH_VARIANT
895 scoreboard_init (sack_scoreboard_t * sb)
897 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
898 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
899 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
903 scoreboard_clear (sack_scoreboard_t * sb)
905 sack_scoreboard_hole_t *hole;
906 while ((hole = scoreboard_first_hole (sb)))
908 scoreboard_remove_hole (sb, hole);
910 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
911 ASSERT (pool_elts (sb->holes) == 0);
912 sb->sacked_bytes = 0;
913 sb->last_sacked_bytes = 0;
914 sb->last_bytes_delivered = 0;
919 sb->last_lost_bytes = 0;
920 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
922 #endif /* CLIB_MARCH_VARIANT */
925 * Test that scoreboard is sane after recovery
927 * Returns 1 if scoreboard is empty or if first hole beyond
931 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
933 sack_scoreboard_hole_t *hole;
934 hole = scoreboard_first_hole (&tc->sack_sb);
935 return (!hole || (seq_geq (hole->start, tc->snd_una)
936 && seq_lt (hole->end, tc->snd_nxt)));
939 #ifndef CLIB_MARCH_VARIANT
942 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
944 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
945 u32 blk_index = 0, old_sacked_bytes, hole_index;
946 sack_scoreboard_t *sb = &tc->sack_sb;
947 sack_block_t *blk, tmp;
950 sb->last_sacked_bytes = 0;
951 sb->last_bytes_delivered = 0;
954 if (!tcp_opts_sack (&tc->rcv_opts)
955 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
958 old_sacked_bytes = sb->sacked_bytes;
960 /* Remove invalid blocks */
961 blk = tc->rcv_opts.sacks;
962 while (blk < vec_end (tc->rcv_opts.sacks))
964 if (seq_lt (blk->start, blk->end)
965 && seq_gt (blk->start, tc->snd_una)
966 && seq_gt (blk->start, ack)
967 && seq_lt (blk->start, tc->snd_nxt)
968 && seq_leq (blk->end, tc->snd_nxt))
973 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
976 /* Add block for cumulative ack */
977 if (seq_gt (ack, tc->snd_una))
979 tmp.start = tc->snd_una;
981 vec_add1 (tc->rcv_opts.sacks, tmp);
984 if (vec_len (tc->rcv_opts.sacks) == 0)
987 tcp_scoreboard_trace_add (tc, ack);
989 /* Make sure blocks are ordered */
990 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
991 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
992 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
994 tmp = tc->rcv_opts.sacks[i];
995 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
996 tc->rcv_opts.sacks[j] = tmp;
999 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
1001 /* If no holes, insert the first that covers all outstanding bytes */
1002 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
1003 tc->snd_una, tc->snd_nxt);
1004 sb->tail = scoreboard_hole_index (sb, last_hole);
1005 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
1006 sb->high_sacked = tmp.end;
1010 /* If we have holes but snd_una_max is beyond the last hole, update
1012 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
1013 last_hole = scoreboard_last_hole (sb);
1014 if (seq_gt (tc->snd_nxt, last_hole->end))
1016 if (seq_geq (last_hole->start, sb->high_sacked))
1018 last_hole->end = tc->snd_nxt;
1020 /* New hole after high sacked block */
1021 else if (seq_lt (sb->high_sacked, tc->snd_nxt))
1023 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
1027 /* Keep track of max byte sacked for when the last hole
1029 if (seq_gt (tmp.end, sb->high_sacked))
1030 sb->high_sacked = tmp.end;
1033 /* Walk the holes with the SACK blocks */
1034 hole = pool_elt_at_index (sb->holes, sb->head);
1035 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
1037 blk = &tc->rcv_opts.sacks[blk_index];
1038 if (seq_leq (blk->start, hole->start))
1040 /* Block covers hole. Remove hole */
1041 if (seq_geq (blk->end, hole->end))
1043 next_hole = scoreboard_next_hole (sb, hole);
1045 /* Byte accounting: snd_una needs to be advanced */
1046 if (blk->end == ack)
1050 if (seq_lt (ack, next_hole->start))
1051 sb->snd_una_adv = next_hole->start - ack;
1052 sb->last_bytes_delivered +=
1053 next_hole->start - hole->end;
1057 ASSERT (seq_geq (sb->high_sacked, ack));
1058 sb->snd_una_adv = sb->high_sacked - ack;
1059 sb->last_bytes_delivered += sb->high_sacked - hole->end;
1062 scoreboard_remove_hole (sb, hole);
1065 /* Partial 'head' overlap */
1068 if (seq_gt (blk->end, hole->start))
1070 hole->start = blk->end;
1077 /* Hole must be split */
1078 if (seq_lt (blk->end, hole->end))
1080 hole_index = scoreboard_hole_index (sb, hole);
1081 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
1084 /* Pool might've moved */
1085 hole = scoreboard_get_hole (sb, hole_index);
1086 hole->end = blk->start;
1088 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
1090 else if (seq_lt (blk->start, hole->end))
1092 hole->end = blk->start;
1094 hole = scoreboard_next_hole (sb, hole);
1098 if (pool_elts (sb->holes) == 1)
1100 hole = scoreboard_first_hole (sb);
1101 if (hole->start == ack + sb->snd_una_adv && hole->end == tc->snd_nxt)
1102 scoreboard_remove_hole (sb, hole);
1105 scoreboard_update_bytes (tc, sb);
1106 sb->last_sacked_bytes = sb->sacked_bytes
1107 - (old_sacked_bytes - sb->last_bytes_delivered);
1109 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
1110 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
1111 || sb->sacked_bytes < tc->snd_nxt - seq_max (tc->snd_una, ack));
1112 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_nxt
1113 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1114 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1115 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
1116 ASSERT (sb->last_lost_bytes <= sb->lost_bytes);
1118 TCP_EVT_DBG (TCP_EVT_CC_SCOREBOARD, tc);
1120 #endif /* CLIB_MARCH_VARIANT */
1123 * Try to update snd_wnd based on feedback received from peer.
1125 * If successful, and new window is 'effectively' 0, activate persist
1129 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1131 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1132 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1133 if (seq_lt (tc->snd_wl1, seq)
1134 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1136 tc->snd_wnd = snd_wnd;
1139 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
1141 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
1143 /* Set persist timer if not set and we just got 0 wnd */
1144 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1145 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1146 tcp_persist_timer_set (tc);
1150 tcp_persist_timer_reset (tc);
1151 if (PREDICT_FALSE (!tcp_in_recovery (tc) && tc->rto_boff > 0))
1154 tcp_update_rto (tc);
1160 #ifndef CLIB_MARCH_VARIANT
1162 * Init loss recovery/fast recovery.
1164 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1165 * updated in @ref tcp_cc_handle_event after fast retransmit
1168 tcp_cc_init_congestion (tcp_connection_t * tc)
1170 tcp_fastrecovery_on (tc);
1171 tc->snd_congestion = tc->snd_nxt;
1172 tc->cwnd_acc_bytes = 0;
1173 tc->snd_rxt_bytes = 0;
1174 tc->prev_ssthresh = tc->ssthresh;
1175 tc->prev_cwnd = tc->cwnd;
1176 tc->cc_algo->congestion (tc);
1177 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
1179 #endif /* CLIB_MARCH_VARIANT */
1182 tcp_cc_recovery_exit (tcp_connection_t * tc)
1185 tcp_update_rto (tc);
1188 tcp_recovery_off (tc);
1189 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1192 #ifndef CLIB_MARCH_VARIANT
1194 tcp_cc_fastrecovery_clear (tcp_connection_t * tc)
1196 tc->snd_rxt_bytes = 0;
1197 tc->rcv_dupacks = 0;
1200 tcp_fastrecovery_off (tc);
1201 tcp_fastrecovery_first_off (tc);
1203 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1205 #endif /* CLIB_MARCH_VARIANT */
1208 tcp_cc_congestion_undo (tcp_connection_t * tc)
1210 tc->cwnd = tc->prev_cwnd;
1211 tc->ssthresh = tc->prev_ssthresh;
1212 tc->rcv_dupacks = 0;
1213 if (tcp_in_recovery (tc))
1215 tcp_cc_recovery_exit (tc);
1216 tc->snd_nxt = seq_max (tc->snd_nxt, tc->snd_congestion);
1218 else if (tcp_in_fastrecovery (tc))
1220 tcp_cc_fastrecovery_clear (tc);
1222 tcp_cc_undo_recovery (tc);
1223 ASSERT (tc->rto_boff == 0);
1224 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
1228 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1230 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1232 && tcp_opts_tstamp (&tc->rcv_opts)
1233 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1237 tcp_cc_is_spurious_fast_rxt (tcp_connection_t * tc)
1239 return (tcp_in_fastrecovery (tc)
1240 && tc->cwnd > tc->ssthresh + 3 * tc->snd_mss);
1244 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1246 return (tcp_cc_is_spurious_timeout_rxt (tc)
1247 || tcp_cc_is_spurious_fast_rxt (tc));
1251 tcp_cc_recover (tcp_connection_t * tc)
1253 ASSERT (tcp_in_cong_recovery (tc));
1254 if (tcp_cc_is_spurious_retransmit (tc))
1256 tcp_cc_congestion_undo (tc);
1260 if (tcp_in_recovery (tc))
1261 tcp_cc_recovery_exit (tc);
1262 else if (tcp_in_fastrecovery (tc))
1264 tcp_cc_recovered (tc);
1265 tcp_cc_fastrecovery_clear (tc);
1268 ASSERT (tc->rto_boff == 0);
1269 ASSERT (!tcp_in_cong_recovery (tc));
1270 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1275 tcp_cc_update (tcp_connection_t * tc, tcp_rate_sample_t * rs)
1277 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1279 /* Congestion avoidance */
1280 tcp_cc_rcv_ack (tc, rs);
1282 /* If a cumulative ack, make sure dupacks is 0 */
1283 tc->rcv_dupacks = 0;
1285 /* When dupacks hits the threshold we only enter fast retransmit if
1286 * cumulative ack covers more than snd_congestion. Should snd_una
1287 * wrap this test may fail under otherwise valid circumstances.
1288 * Therefore, proactively update snd_congestion when wrap detected. */
1290 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1291 && seq_gt (tc->snd_congestion, tc->snd_una)))
1292 tc->snd_congestion = tc->snd_una - 1;
1296 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1298 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1302 tcp_should_fastrecover (tcp_connection_t * tc)
1304 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1305 || tcp_should_fastrecover_sack (tc));
1308 #ifndef CLIB_MARCH_VARIANT
1310 tcp_program_fastretransmit (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1312 if (!(tc->flags & TCP_CONN_FRXT_PENDING))
1314 vec_add1 (wrk->pending_fast_rxt, tc->c_c_index);
1315 tc->flags |= TCP_CONN_FRXT_PENDING;
1320 tcp_do_fastretransmits (tcp_worker_ctx_t * wrk)
1322 u32 *ongoing_fast_rxt, burst_bytes, sent_bytes, thread_index;
1323 u32 max_burst_size, burst_size, n_segs = 0, n_segs_now;
1324 tcp_connection_t *tc;
1328 if (vec_len (wrk->pending_fast_rxt) == 0
1329 && vec_len (wrk->postponed_fast_rxt) == 0)
1332 thread_index = wrk->vm->thread_index;
1333 last_cpu_time = wrk->vm->clib_time.last_cpu_time;
1334 ongoing_fast_rxt = wrk->ongoing_fast_rxt;
1335 vec_append (ongoing_fast_rxt, wrk->postponed_fast_rxt);
1336 vec_append (ongoing_fast_rxt, wrk->pending_fast_rxt);
1338 _vec_len (wrk->postponed_fast_rxt) = 0;
1339 _vec_len (wrk->pending_fast_rxt) = 0;
1341 max_burst_size = VLIB_FRAME_SIZE / vec_len (ongoing_fast_rxt);
1342 max_burst_size = clib_max (max_burst_size, 1);
1344 for (i = 0; i < vec_len (ongoing_fast_rxt); i++)
1346 tc = tcp_connection_get (ongoing_fast_rxt[i], thread_index);
1349 if (!tcp_in_fastrecovery (tc))
1351 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1355 if (n_segs >= VLIB_FRAME_SIZE)
1357 vec_add1 (wrk->postponed_fast_rxt, ongoing_fast_rxt[i]);
1361 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1362 burst_size = clib_min (max_burst_size, VLIB_FRAME_SIZE - n_segs);
1363 burst_bytes = transport_connection_tx_pacer_burst (&tc->connection,
1365 burst_size = clib_min (burst_size, burst_bytes / tc->snd_mss);
1368 tcp_program_fastretransmit (wrk, tc);
1372 n_segs_now = tcp_fast_retransmit (wrk, tc, burst_size);
1373 sent_bytes = clib_min (n_segs_now * tc->snd_mss, burst_bytes);
1374 transport_connection_tx_pacer_update_bytes (&tc->connection,
1376 n_segs += n_segs_now;
1378 _vec_len (ongoing_fast_rxt) = 0;
1379 wrk->ongoing_fast_rxt = ongoing_fast_rxt;
1381 #endif /* CLIB_MARCH_VARIANT */
1384 * One function to rule them all ... and in the darkness bind them
1387 tcp_cc_handle_event (tcp_connection_t * tc, tcp_rate_sample_t * rs,
1392 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1394 if (tc->bytes_acked)
1396 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1400 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1401 * it account for the bytes that left the network.
1403 else if (is_dack && !tcp_in_recovery (tc))
1405 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1406 ASSERT (tc->snd_una != tc->snd_nxt || tc->sack_sb.last_sacked_bytes);
1410 /* Pure duplicate ack. If some data got acked, it's handled lower */
1411 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1413 ASSERT (tcp_in_fastrecovery (tc));
1414 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1417 else if (tcp_should_fastrecover (tc))
1421 ASSERT (!tcp_in_fastrecovery (tc));
1423 /* Heuristic to catch potential late dupacks
1424 * after fast retransmit exits */
1425 if (is_dack && tc->snd_una == tc->snd_congestion
1426 && timestamp_leq (tc->rcv_opts.tsecr, tc->tsecr_last_ack))
1428 tc->rcv_dupacks = 0;
1432 tcp_cc_init_congestion (tc);
1433 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1435 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1437 tc->cwnd = tc->ssthresh;
1438 scoreboard_init_high_rxt (&tc->sack_sb, tc->snd_una);
1442 /* Post retransmit update cwnd to ssthresh and account for the
1443 * three segments that have left the network and should've been
1444 * buffered at the receiver XXX */
1445 tc->cwnd = tc->ssthresh + 3 * tc->snd_mss;
1448 /* Constrain rate until we get a partial ack */
1449 pacer_wnd = clib_max (0.1 * tc->cwnd, 2 * tc->snd_mss);
1450 tcp_connection_tx_pacer_reset (tc, pacer_wnd,
1451 0 /* start bucket */ );
1452 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index),
1456 else if (!tc->bytes_acked
1457 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1459 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1465 /* Don't allow entry in fast recovery if still in recovery, for now */
1466 else if (0 && is_dack && tcp_in_recovery (tc))
1468 /* If of of the two conditions lower hold, reset dupacks because
1469 * we're probably after timeout (RFC6582 heuristics).
1470 * If Cumulative ack does not cover more than congestion threshold,
1472 * 1) The following doesn't hold: The congestion window is greater
1473 * than SMSS bytes and the difference between highest_ack
1474 * and prev_highest_ack is at most 4*SMSS bytes
1475 * 2) Echoed timestamp in the last non-dup ack does not equal the
1478 if (seq_leq (tc->snd_una, tc->snd_congestion)
1479 && ((!(tc->cwnd > tc->snd_mss
1480 && tc->bytes_acked <= 4 * tc->snd_mss))
1481 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1483 tc->rcv_dupacks = 0;
1488 if (!tc->bytes_acked)
1492 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1495 * Legitimate ACK. 1) See if we can exit recovery
1498 /* Update the pacing rate. For the first partial ack we move from
1499 * the artificially constrained rate to the one after congestion */
1500 tcp_connection_tx_pacer_update (tc);
1502 if (seq_geq (tc->snd_una, tc->snd_congestion))
1504 tcp_retransmit_timer_update (tc);
1506 /* If spurious return, we've already updated everything */
1507 if (tcp_cc_recover (tc))
1509 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1513 /* Treat as congestion avoidance ack */
1514 tcp_cc_rcv_ack (tc, rs);
1519 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1522 /* XXX limit this only to first partial ack? */
1523 tcp_retransmit_timer_update (tc);
1525 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1526 * reset dupacks to 0. Also needed if in congestion recovery */
1527 tc->rcv_dupacks = 0;
1529 /* Post RTO timeout don't try anything fancy */
1530 if (tcp_in_recovery (tc))
1532 tcp_cc_rcv_ack (tc, rs);
1533 transport_add_tx_event (&tc->connection);
1537 /* Remove retransmitted bytes that have been delivered */
1538 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1540 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1541 >= tc->sack_sb.last_bytes_delivered
1542 || (tc->flags & TCP_CONN_FINSNT));
1544 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1545 * remove sacked bytes delivered */
1546 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1548 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1549 - tc->sack_sb.last_bytes_delivered;
1550 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1551 tc->snd_rxt_bytes -= rxt_delivered;
1555 /* Apparently all retransmitted holes have been acked */
1556 tc->snd_rxt_bytes = 0;
1557 tc->sack_sb.high_rxt = tc->snd_una;
1562 tcp_fastrecovery_first_on (tc);
1563 if (tc->snd_rxt_bytes > tc->bytes_acked)
1564 tc->snd_rxt_bytes -= tc->bytes_acked;
1566 tc->snd_rxt_bytes = 0;
1569 tcp_cc_rcv_cong_ack (tc, TCP_CC_PARTIALACK, rs);
1572 * Since this was a partial ack, try to retransmit some more data
1574 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1578 * Process incoming ACK
1581 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1582 tcp_header_t * th, u32 * error)
1584 u32 prev_snd_wnd, prev_snd_una;
1585 tcp_rate_sample_t rs = { 0 };
1588 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1590 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1591 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1593 /* We've probably entered recovery and the peer still has some
1594 * of the data we've sent. Update snd_nxt and accept the ack */
1595 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)
1596 && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
1598 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1602 *error = TCP_ERROR_ACK_FUTURE;
1603 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1604 vnet_buffer (b)->tcp.ack_number);
1608 /* If old ACK, probably it's an old dupack */
1609 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1611 *error = TCP_ERROR_ACK_OLD;
1612 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1613 vnet_buffer (b)->tcp.ack_number);
1614 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1615 tcp_cc_handle_event (tc, 0, 1);
1616 /* Don't drop yet */
1623 * Looks okay, process feedback
1625 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1626 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1628 prev_snd_wnd = tc->snd_wnd;
1629 prev_snd_una = tc->snd_una;
1630 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1631 vnet_buffer (b)->tcp.ack_number,
1632 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1633 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1634 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1635 tcp_validate_txf_size (tc, tc->bytes_acked);
1637 if (tc->bytes_acked)
1639 tcp_program_dequeue (wrk, tc);
1640 tcp_update_rtt (tc, vnet_buffer (b)->tcp.ack_number);
1643 if (tc->flags & TCP_CONN_RATE_SAMPLE)
1644 tcp_bt_sample_delivery_rate (tc, &rs);
1646 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1649 * Check if we have congestion event
1652 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1654 tcp_cc_handle_event (tc, &rs, is_dack);
1655 if (!tcp_in_cong_recovery (tc))
1657 *error = TCP_ERROR_ACK_OK;
1660 *error = TCP_ERROR_ACK_DUP;
1661 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1667 * Update congestion control (slow start/congestion avoidance)
1669 tcp_cc_update (tc, &rs);
1670 *error = TCP_ERROR_ACK_OK;
1675 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1677 if (!tcp_disconnect_pending (tc))
1679 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1680 tcp_disconnect_pending_on (tc);
1685 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1687 u32 thread_index, *pending_disconnects;
1688 tcp_connection_t *tc;
1691 if (!vec_len (wrk->pending_disconnects))
1694 thread_index = wrk->vm->thread_index;
1695 pending_disconnects = wrk->pending_disconnects;
1696 for (i = 0; i < vec_len (pending_disconnects); i++)
1698 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1699 tcp_disconnect_pending_off (tc);
1700 session_transport_closing_notify (&tc->connection);
1702 _vec_len (wrk->pending_disconnects) = 0;
1706 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1709 /* Reject out-of-order fins */
1710 if (vnet_buffer (b)->tcp.seq_end != tc->rcv_nxt)
1713 /* Account for the FIN and send ack */
1715 tcp_program_ack (wrk, tc);
1716 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1717 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1718 tcp_connection_set_state (tc, TCP_STATE_CLOSE_WAIT);
1719 tcp_program_disconnect (wrk, tc);
1720 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1721 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc);
1722 *error = TCP_ERROR_FIN_RCVD;
1725 #ifndef CLIB_MARCH_VARIANT
1727 tcp_sack_vector_is_sane (sack_block_t * sacks)
1730 for (i = 1; i < vec_len (sacks); i++)
1732 if (sacks[i - 1].end == sacks[i].start)
1739 * Build SACK list as per RFC2018.
1741 * Makes sure the first block contains the segment that generated the current
1742 * ACK and the following ones are the ones most recently reported in SACK
1745 * @param tc TCP connection for which the SACK list is updated
1746 * @param start Start sequence number of the newest SACK block
1747 * @param end End sequence of the newest SACK block
1750 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1752 sack_block_t *new_list = tc->snd_sacks_fl, *block = 0;
1755 /* If the first segment is ooo add it to the list. Last write might've moved
1756 * rcv_nxt over the first segment. */
1757 if (seq_lt (tc->rcv_nxt, start))
1759 vec_add2 (new_list, block, 1);
1760 block->start = start;
1764 /* Find the blocks still worth keeping. */
1765 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1767 /* Discard if rcv_nxt advanced beyond current block */
1768 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1771 /* Merge or drop if segment overlapped by the new segment */
1772 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1773 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1775 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1776 new_list[0].start = tc->snd_sacks[i].start;
1777 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1778 new_list[0].end = tc->snd_sacks[i].end;
1782 /* Save to new SACK list if we have space. */
1783 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1784 vec_add1 (new_list, tc->snd_sacks[i]);
1787 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1789 /* Replace old vector with new one */
1790 vec_reset_length (tc->snd_sacks);
1791 tc->snd_sacks_fl = tc->snd_sacks;
1792 tc->snd_sacks = new_list;
1794 /* Segments should not 'touch' */
1795 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1799 tcp_sack_list_bytes (tcp_connection_t * tc)
1802 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1803 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1806 #endif /* CLIB_MARCH_VARIANT */
1808 /** Enqueue data for delivery to application */
1810 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1813 int written, error = TCP_ERROR_ENQUEUED;
1815 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1817 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1818 1 /* queue event */ , 1);
1820 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1822 /* Update rcv_nxt */
1823 if (PREDICT_TRUE (written == data_len))
1825 tc->rcv_nxt += written;
1827 /* If more data written than expected, account for out-of-order bytes. */
1828 else if (written > data_len)
1830 tc->rcv_nxt += written;
1831 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1833 else if (written > 0)
1835 /* We've written something but FIFO is probably full now */
1836 tc->rcv_nxt += written;
1837 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1841 return TCP_ERROR_FIFO_FULL;
1844 /* Update SACK list if need be */
1845 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1847 /* Remove SACK blocks that have been delivered */
1848 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1854 /** Enqueue out-of-order data */
1856 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1862 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1865 /* Enqueue out-of-order data with relative offset */
1866 rv = session_enqueue_stream_connection (&tc->connection, b,
1867 vnet_buffer (b)->tcp.seq_number -
1868 tc->rcv_nxt, 0 /* queue event */ ,
1871 /* Nothing written */
1874 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1875 return TCP_ERROR_FIFO_FULL;
1878 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1880 /* Update SACK list if in use */
1881 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1883 ooo_segment_t *newest;
1886 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1888 /* Get the newest segment from the fifo */
1889 newest = svm_fifo_newest_ooo_segment (s0->rx_fifo);
1892 offset = ooo_segment_offset_prod (s0->rx_fifo, newest);
1893 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1894 start = tc->rcv_nxt + offset;
1895 end = start + ooo_segment_length (s0->rx_fifo, newest);
1896 tcp_update_sack_list (tc, start, end);
1897 svm_fifo_newest_ooo_segment_reset (s0->rx_fifo);
1898 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1902 return TCP_ERROR_ENQUEUED_OOO;
1906 * Check if ACK could be delayed. If ack can be delayed, it should return
1907 * true for a full frame. If we're always acking return 0.
1910 tcp_can_delack (tcp_connection_t * tc)
1912 /* Send ack if ... */
1914 /* just sent a rcv wnd 0
1915 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0 */
1916 /* constrained to send ack */
1917 || (tc->flags & TCP_CONN_SNDACK) != 0
1918 /* we're almost out of tx wnd */
1919 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1926 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1928 u32 discard, first = b->current_length;
1929 vlib_main_t *vm = vlib_get_main ();
1931 /* Handle multi-buffer segments */
1932 if (n_bytes_to_drop > b->current_length)
1934 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1938 discard = clib_min (n_bytes_to_drop, b->current_length);
1939 vlib_buffer_advance (b, discard);
1940 b = vlib_get_buffer (vm, b->next_buffer);
1941 n_bytes_to_drop -= discard;
1943 while (n_bytes_to_drop);
1944 if (n_bytes_to_drop > first)
1945 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1948 vlib_buffer_advance (b, n_bytes_to_drop);
1949 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1954 * Receive buffer for connection and handle acks
1956 * It handles both in order or out-of-order data.
1959 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1962 u32 error, n_bytes_to_drop, n_data_bytes;
1964 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1965 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1966 ASSERT (n_data_bytes);
1968 /* Handle out-of-order data */
1969 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1971 /* Old sequence numbers allowed through because they overlapped
1973 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1975 /* Completely in the past (possible retransmit). Ack
1976 * retransmissions since we may not have any data to send */
1977 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1979 tcp_program_ack (wrk, tc);
1980 error = TCP_ERROR_SEGMENT_OLD;
1984 /* Chop off the bytes in the past and see if what is left
1985 * can be enqueued in order */
1986 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1987 n_data_bytes -= n_bytes_to_drop;
1988 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1989 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1991 error = TCP_ERROR_SEGMENT_OLD;
1997 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1998 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1999 tcp_program_dupack (wrk, tc);
2000 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
2006 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
2007 * segments can be enqueued after fifo tail offset changes. */
2008 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
2009 if (tcp_can_delack (tc))
2011 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
2012 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
2016 tcp_program_ack (wrk, tc);
2024 tcp_header_t tcp_header;
2025 tcp_connection_t tcp_connection;
2029 format_tcp_rx_trace (u8 * s, va_list * args)
2031 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2032 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2033 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2034 u32 indent = format_get_indent (s);
2036 s = format (s, "%U\n%U%U",
2037 format_tcp_header, &t->tcp_header, 128,
2038 format_white_space, indent,
2039 format_tcp_connection, &t->tcp_connection, 1);
2045 format_tcp_rx_trace_short (u8 * s, va_list * args)
2047 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2048 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2049 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2051 s = format (s, "%d -> %d (%U)",
2052 clib_net_to_host_u16 (t->tcp_header.dst_port),
2053 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
2054 t->tcp_connection.state);
2060 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
2061 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
2065 clib_memcpy_fast (&t0->tcp_connection, tc0,
2066 sizeof (t0->tcp_connection));
2070 th0 = tcp_buffer_hdr (b0);
2072 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2076 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2077 vlib_frame_t * frame, u8 is_ip4)
2081 n_left = frame->n_vectors;
2082 from = vlib_frame_vector_args (frame);
2086 tcp_connection_t *tc0;
2093 b0 = vlib_get_buffer (vm, bi0);
2095 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2097 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2098 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2100 th0 = tcp_buffer_hdr (b0);
2101 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2110 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2111 u8 is_ip4, u32 evt, u32 val)
2114 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2116 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2119 #define tcp_maybe_inc_counter(node_id, err, count) \
2121 if (next0 != tcp_next_drop (is_ip4)) \
2122 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2123 tcp6_##node_id##_node.index, is_ip4, err, \
2126 #define tcp_inc_counter(node_id, err, count) \
2127 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2128 tcp6_##node_id##_node.index, is_ip4, \
2130 #define tcp_maybe_inc_err_counter(cnts, err) \
2132 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2134 #define tcp_inc_err_counter(cnts, err, val) \
2138 #define tcp_store_err_counters(node_id, cnts) \
2141 for (i = 0; i < TCP_N_ERROR; i++) \
2143 tcp_inc_counter(node_id, i, cnts[i]); \
2148 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2149 vlib_frame_t * frame, int is_ip4)
2151 u32 thread_index = vm->thread_index, errors = 0;
2152 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2153 u32 n_left_from, *from, *first_buffer;
2154 u16 err_counters[TCP_N_ERROR] = { 0 };
2156 if (node->flags & VLIB_NODE_FLAG_TRACE)
2157 tcp_established_trace_frame (vm, node, frame, is_ip4);
2159 first_buffer = from = vlib_frame_vector_args (frame);
2160 n_left_from = frame->n_vectors;
2162 while (n_left_from > 0)
2164 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2167 tcp_connection_t *tc0;
2169 if (n_left_from > 1)
2172 pb = vlib_get_buffer (vm, from[1]);
2173 vlib_prefetch_buffer_header (pb, LOAD);
2174 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2181 b0 = vlib_get_buffer (vm, bi0);
2182 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2185 if (PREDICT_FALSE (tc0 == 0))
2187 error0 = TCP_ERROR_INVALID_CONNECTION;
2191 th0 = tcp_buffer_hdr (b0);
2193 /* TODO header prediction fast path */
2195 /* 1-4: check SEQ, RST, SYN */
2196 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2198 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2202 /* 5: check the ACK field */
2203 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2206 /* 6: check the URG bit TODO */
2208 /* 7: process the segment text */
2209 if (vnet_buffer (b0)->tcp.data_len)
2210 error0 = tcp_segment_rcv (wrk, tc0, b0);
2212 /* 8: check the FIN bit */
2213 if (PREDICT_FALSE (tcp_is_fin (th0)))
2214 tcp_rcv_fin (wrk, tc0, b0, &error0);
2217 tcp_inc_err_counter (err_counters, error0, 1);
2220 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2222 err_counters[TCP_ERROR_MSG_QUEUE_FULL] = errors;
2223 tcp_store_err_counters (established, err_counters);
2224 tcp_handle_postponed_dequeues (wrk);
2225 tcp_handle_disconnects (wrk);
2226 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2228 return frame->n_vectors;
2231 VLIB_NODE_FN (tcp4_established_node) (vlib_main_t * vm,
2232 vlib_node_runtime_t * node,
2233 vlib_frame_t * from_frame)
2235 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2238 VLIB_NODE_FN (tcp6_established_node) (vlib_main_t * vm,
2239 vlib_node_runtime_t * node,
2240 vlib_frame_t * from_frame)
2242 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2246 VLIB_REGISTER_NODE (tcp4_established_node) =
2248 .name = "tcp4-established",
2249 /* Takes a vector of packets. */
2250 .vector_size = sizeof (u32),
2251 .n_errors = TCP_N_ERROR,
2252 .error_strings = tcp_error_strings,
2253 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2256 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2257 foreach_tcp_state_next
2260 .format_trace = format_tcp_rx_trace_short,
2265 VLIB_REGISTER_NODE (tcp6_established_node) =
2267 .name = "tcp6-established",
2268 /* Takes a vector of packets. */
2269 .vector_size = sizeof (u32),
2270 .n_errors = TCP_N_ERROR,
2271 .error_strings = tcp_error_strings,
2272 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2275 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2276 foreach_tcp_state_next
2279 .format_trace = format_tcp_rx_trace_short,
2285 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2287 transport_connection_t *tmp = 0;
2294 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2297 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2298 && (tc->state == TCP_STATE_LISTEN
2299 || tc->c_rmt_port == hdr->src_port));
2303 handle = session_lookup_half_open_handle (&tc->connection);
2304 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2305 tc->c_proto, tc->c_is_ip4);
2309 if (tmp->lcl_port == hdr->dst_port
2310 && tmp->rmt_port == hdr->src_port)
2312 TCP_DBG ("half-open is valid!");
2320 * Lookup transport connection
2322 static tcp_connection_t *
2323 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2327 transport_connection_t *tconn;
2328 tcp_connection_t *tc;
2333 ip4 = vlib_buffer_get_current (b);
2334 tcp = ip4_next_header (ip4);
2335 tconn = session_lookup_connection_wt4 (fib_index,
2340 TRANSPORT_PROTO_TCP,
2341 thread_index, &is_filtered);
2342 tc = tcp_get_connection_from_transport (tconn);
2343 ASSERT (tcp_lookup_is_valid (tc, tcp));
2348 ip6 = vlib_buffer_get_current (b);
2349 tcp = ip6_next_header (ip6);
2350 tconn = session_lookup_connection_wt6 (fib_index,
2355 TRANSPORT_PROTO_TCP,
2356 thread_index, &is_filtered);
2357 tc = tcp_get_connection_from_transport (tconn);
2358 ASSERT (tcp_lookup_is_valid (tc, tcp));
2364 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2365 vlib_frame_t * from_frame, int is_ip4)
2367 tcp_main_t *tm = vnet_get_tcp_main ();
2368 u32 n_left_from, *from, *first_buffer, errors = 0;
2369 u32 my_thread_index = vm->thread_index;
2370 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2372 from = first_buffer = vlib_frame_vector_args (from_frame);
2373 n_left_from = from_frame->n_vectors;
2375 while (n_left_from > 0)
2377 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2378 tcp_connection_t *tc0, *new_tc0;
2379 tcp_header_t *tcp0 = 0;
2387 b0 = vlib_get_buffer (vm, bi0);
2389 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2390 if (PREDICT_FALSE (tc0 == 0))
2392 error0 = TCP_ERROR_INVALID_CONNECTION;
2396 /* Half-open completed recently but the connection was't removed
2397 * yet by the owning thread */
2398 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2400 /* Make sure the connection actually exists */
2401 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2402 my_thread_index, is_ip4));
2403 error0 = TCP_ERROR_SPURIOUS_SYN_ACK;
2407 ack0 = vnet_buffer (b0)->tcp.ack_number;
2408 seq0 = vnet_buffer (b0)->tcp.seq_number;
2409 tcp0 = tcp_buffer_hdr (b0);
2411 /* Crude check to see if the connection handle does not match
2412 * the packet. Probably connection just switched to established */
2413 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2414 || tcp0->src_port != tc0->c_rmt_port))
2416 error0 = TCP_ERROR_INVALID_CONNECTION;
2420 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2421 && !tcp_syn (tcp0)))
2423 error0 = TCP_ERROR_SEGMENT_INVALID;
2427 /* SYNs consume sequence numbers */
2428 vnet_buffer (b0)->tcp.seq_end += tcp_is_syn (tcp0);
2431 * 1. check the ACK bit
2435 * If the ACK bit is set
2436 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2437 * the RST bit is set, if so drop the segment and return)
2438 * <SEQ=SEG.ACK><CTL=RST>
2439 * and discard the segment. Return.
2440 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2444 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2446 if (!tcp_rst (tcp0))
2447 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2448 error0 = TCP_ERROR_RCV_WND;
2452 /* Make sure ACK is valid */
2453 if (seq_gt (tc0->snd_una, ack0))
2455 error0 = TCP_ERROR_ACK_INVALID;
2461 * 2. check the RST bit
2466 /* If ACK is acceptable, signal client that peer is not
2467 * willing to accept connection and drop connection*/
2469 tcp_connection_reset (tc0);
2470 error0 = TCP_ERROR_RST_RCVD;
2475 * 3. check the security and precedence (skipped)
2479 * 4. check the SYN bit
2482 /* No SYN flag. Drop. */
2483 if (!tcp_syn (tcp0))
2485 error0 = TCP_ERROR_SEGMENT_INVALID;
2490 if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1))
2492 error0 = TCP_ERROR_OPTIONS;
2496 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2497 * current thread pool. */
2498 pool_get (tm->connections[my_thread_index], new_tc0);
2499 clib_memcpy_fast (new_tc0, tc0, sizeof (*new_tc0));
2500 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2501 new_tc0->c_thread_index = my_thread_index;
2502 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2503 new_tc0->irs = seq0;
2504 new_tc0->timers[TCP_TIMER_ESTABLISH_AO] = TCP_TIMER_HANDLE_INVALID;
2505 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2506 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2508 /* If this is not the owning thread, wait for syn retransmit to
2509 * expire and cleanup then */
2510 if (tcp_half_open_connection_cleanup (tc0))
2511 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2513 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2515 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2516 new_tc0->tsval_recent_age = tcp_time_now ();
2519 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2520 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2522 new_tc0->rcv_wscale = 0;
2524 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2525 << new_tc0->snd_wscale;
2526 new_tc0->snd_wl1 = seq0;
2527 new_tc0->snd_wl2 = ack0;
2529 tcp_connection_init_vars (new_tc0);
2531 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2532 if (PREDICT_TRUE (tcp_ack (tcp0)))
2534 /* Our SYN is ACKed: we have iss < ack = snd_una */
2536 /* TODO Dequeue acknowledged segments if we support Fast Open */
2537 new_tc0->snd_una = ack0;
2538 new_tc0->state = TCP_STATE_ESTABLISHED;
2540 /* Make sure las is initialized for the wnd computation */
2541 new_tc0->rcv_las = new_tc0->rcv_nxt;
2543 /* Notify app that we have connection. If session layer can't
2544 * allocate session send reset */
2545 if (session_stream_connect_notify (&new_tc0->connection, 0))
2547 tcp_send_reset_w_pkt (new_tc0, b0, my_thread_index, is_ip4);
2548 tcp_connection_cleanup (new_tc0);
2549 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2553 new_tc0->tx_fifo_size =
2554 transport_tx_fifo_size (&new_tc0->connection);
2555 /* Update rtt with the syn-ack sample */
2556 tcp_estimate_initial_rtt (new_tc0);
2557 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2558 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2560 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2563 new_tc0->state = TCP_STATE_SYN_RCVD;
2565 /* Notify app that we have connection */
2566 if (session_stream_connect_notify (&new_tc0->connection, 0))
2568 tcp_connection_cleanup (new_tc0);
2569 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2570 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2571 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2575 new_tc0->tx_fifo_size =
2576 transport_tx_fifo_size (&new_tc0->connection);
2577 new_tc0->rtt_ts = 0;
2578 tcp_init_snd_vars (new_tc0);
2579 tcp_send_synack (new_tc0);
2580 error0 = TCP_ERROR_SYNS_RCVD;
2584 /* Read data, if any */
2585 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2587 clib_warning ("rcvd data in syn-sent");
2588 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2589 if (error0 == TCP_ERROR_ACK_OK)
2590 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2594 tcp_program_ack (wrk, new_tc0);
2599 tcp_inc_counter (syn_sent, error0, 1);
2600 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2602 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2603 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2604 clib_memcpy_fast (&t0->tcp_connection, tc0,
2605 sizeof (t0->tcp_connection));
2609 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2611 tcp_inc_counter (syn_sent, TCP_ERROR_MSG_QUEUE_FULL, errors);
2612 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2614 return from_frame->n_vectors;
2617 VLIB_NODE_FN (tcp4_syn_sent_node) (vlib_main_t * vm,
2618 vlib_node_runtime_t * node,
2619 vlib_frame_t * from_frame)
2621 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2624 VLIB_NODE_FN (tcp6_syn_sent_node) (vlib_main_t * vm,
2625 vlib_node_runtime_t * node,
2626 vlib_frame_t * from_frame)
2628 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2632 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2634 .name = "tcp4-syn-sent",
2635 /* Takes a vector of packets. */
2636 .vector_size = sizeof (u32),
2637 .n_errors = TCP_N_ERROR,
2638 .error_strings = tcp_error_strings,
2639 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2642 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2643 foreach_tcp_state_next
2646 .format_trace = format_tcp_rx_trace_short,
2651 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2653 .name = "tcp6-syn-sent",
2654 /* Takes a vector of packets. */
2655 .vector_size = sizeof (u32),
2656 .n_errors = TCP_N_ERROR,
2657 .error_strings = tcp_error_strings,
2658 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2661 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2662 foreach_tcp_state_next
2665 .format_trace = format_tcp_rx_trace_short,
2670 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2671 * as per RFC793 p. 64
2674 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2675 vlib_frame_t * from_frame, int is_ip4)
2677 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2678 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2679 u32 n_left_from, *from, max_dequeue;
2681 from = first_buffer = vlib_frame_vector_args (from_frame);
2682 n_left_from = from_frame->n_vectors;
2684 while (n_left_from > 0)
2686 u32 bi0, error0 = TCP_ERROR_NONE;
2687 tcp_header_t *tcp0 = 0;
2688 tcp_connection_t *tc0;
2696 b0 = vlib_get_buffer (vm, bi0);
2697 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2699 if (PREDICT_FALSE (tc0 == 0))
2701 error0 = TCP_ERROR_INVALID_CONNECTION;
2705 tcp0 = tcp_buffer_hdr (b0);
2706 is_fin0 = tcp_is_fin (tcp0);
2710 tcp_connection_t *tmp;
2711 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2713 if (tmp->state != tc0->state)
2715 if (tc0->state != TCP_STATE_CLOSED)
2716 clib_warning ("state changed");
2722 * Special treatment for CLOSED
2724 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2726 error0 = TCP_ERROR_CONNECTION_CLOSED;
2731 * For all other states (except LISTEN)
2734 /* 1-4: check SEQ, RST, SYN */
2735 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2738 /* 5: check the ACK field */
2741 case TCP_STATE_SYN_RCVD:
2743 /* Make sure the segment is exactly right */
2744 if (tc0->rcv_nxt != vnet_buffer (b0)->tcp.seq_number || is_fin0)
2746 tcp_connection_reset (tc0);
2747 error0 = TCP_ERROR_SEGMENT_INVALID;
2752 * If the segment acknowledgment is not acceptable, form a
2754 * <SEQ=SEG.ACK><CTL=RST>
2757 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2759 tcp_connection_reset (tc0);
2763 /* Update rtt and rto */
2764 tcp_estimate_initial_rtt (tc0);
2766 /* Switch state to ESTABLISHED */
2767 tc0->state = TCP_STATE_ESTABLISHED;
2768 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2770 /* Initialize session variables */
2771 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2772 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2773 << tc0->rcv_opts.wscale;
2774 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2775 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2777 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2778 tcp_retransmit_timer_reset (tc0);
2779 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2780 if (session_stream_accept_notify (&tc0->connection))
2782 error0 = TCP_ERROR_MSG_QUEUE_FULL;
2783 tcp_connection_reset (tc0);
2786 error0 = TCP_ERROR_ACK_OK;
2788 case TCP_STATE_ESTABLISHED:
2789 /* We can get packets in established state here because they
2790 * were enqueued before state change */
2791 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2795 case TCP_STATE_FIN_WAIT_1:
2796 /* In addition to the processing for the ESTABLISHED state, if
2797 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2798 * continue processing in that state. */
2799 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2802 /* Still have to send the FIN */
2803 if (tc0->flags & TCP_CONN_FINPNDG)
2805 /* TX fifo finally drained */
2806 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2807 if (max_dequeue <= tc0->burst_acked)
2809 /* If a fin was received and data was acked extend wait */
2810 else if ((tc0->flags & TCP_CONN_FINRCVD) && tc0->bytes_acked)
2811 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2812 TCP_CLOSEWAIT_TIME);
2814 /* If FIN is ACKed */
2815 else if (tc0->snd_una == tc0->snd_nxt)
2817 /* Stop all retransmit timers because we have nothing more
2819 tcp_connection_timers_reset (tc0);
2821 /* We already have a FIN but didn't transition to CLOSING
2822 * because of outstanding tx data. Close the connection. */
2823 if (tc0->flags & TCP_CONN_FINRCVD)
2825 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2826 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2827 session_transport_closed_notify (&tc0->connection);
2831 tcp_connection_set_state (tc0, TCP_STATE_FIN_WAIT_2);
2832 /* Enable waitclose because we're willing to wait for peer's
2833 * FIN but not indefinitely. */
2834 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2836 /* Don't try to deq the FIN acked */
2837 if (tc0->burst_acked > 1)
2838 session_tx_fifo_dequeue_drop (&tc0->connection,
2839 tc0->burst_acked - 1);
2840 tc0->burst_acked = 0;
2843 case TCP_STATE_FIN_WAIT_2:
2844 /* In addition to the processing for the ESTABLISHED state, if
2845 * the retransmission queue is empty, the user's CLOSE can be
2846 * acknowledged ("ok") but do not delete the TCB. */
2847 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2849 tc0->burst_acked = 0;
2851 case TCP_STATE_CLOSE_WAIT:
2852 /* Do the same processing as for the ESTABLISHED state. */
2853 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2856 if (!(tc0->flags & TCP_CONN_FINPNDG))
2859 /* Still have outstanding tx data */
2860 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2861 if (max_dequeue > tc0->burst_acked)
2865 tcp_connection_timers_reset (tc0);
2866 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2867 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2869 case TCP_STATE_CLOSING:
2870 /* In addition to the processing for the ESTABLISHED state, if
2871 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2872 * otherwise ignore the segment. */
2873 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2876 if (tc0->snd_una != tc0->snd_nxt)
2879 tcp_connection_timers_reset (tc0);
2880 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2881 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2882 session_transport_closed_notify (&tc0->connection);
2886 case TCP_STATE_LAST_ACK:
2887 /* The only thing that [should] arrive in this state is an
2888 * acknowledgment of our FIN. If our FIN is now acknowledged,
2889 * delete the TCB, enter the CLOSED state, and return. */
2891 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2894 /* Apparently our ACK for the peer's FIN was lost */
2895 if (is_fin0 && tc0->snd_una != tc0->snd_nxt)
2901 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2902 session_transport_closed_notify (&tc0->connection);
2904 /* Don't free the connection from the data path since
2905 * we can't ensure that we have no packets already enqueued
2906 * to output. Rely instead on the waitclose timer */
2907 tcp_connection_timers_reset (tc0);
2908 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2913 case TCP_STATE_TIME_WAIT:
2914 /* The only thing that can arrive in this state is a
2915 * retransmission of the remote FIN. Acknowledge it, and restart
2916 * the 2 MSL timeout. */
2918 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2924 tcp_program_ack (wrk, tc0);
2925 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2933 /* 6: check the URG bit TODO */
2935 /* 7: process the segment text */
2938 case TCP_STATE_ESTABLISHED:
2939 case TCP_STATE_FIN_WAIT_1:
2940 case TCP_STATE_FIN_WAIT_2:
2941 if (vnet_buffer (b0)->tcp.data_len)
2942 error0 = tcp_segment_rcv (wrk, tc0, b0);
2944 case TCP_STATE_CLOSE_WAIT:
2945 case TCP_STATE_CLOSING:
2946 case TCP_STATE_LAST_ACK:
2947 case TCP_STATE_TIME_WAIT:
2948 /* This should not occur, since a FIN has been received from the
2949 * remote side. Ignore the segment text. */
2953 /* 8: check the FIN bit */
2957 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2961 case TCP_STATE_ESTABLISHED:
2962 /* Account for the FIN and send ack */
2964 tcp_program_ack (wrk, tc0);
2965 tcp_connection_set_state (tc0, TCP_STATE_CLOSE_WAIT);
2966 tcp_program_disconnect (wrk, tc0);
2967 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
2969 case TCP_STATE_SYN_RCVD:
2970 /* Send FIN-ACK, enter LAST-ACK and because the app was not
2971 * notified yet, set a cleanup timer instead of relying on
2972 * disconnect notify and the implicit close call. */
2973 tcp_connection_timers_reset (tc0);
2976 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2977 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2979 case TCP_STATE_CLOSE_WAIT:
2980 case TCP_STATE_CLOSING:
2981 case TCP_STATE_LAST_ACK:
2984 case TCP_STATE_FIN_WAIT_1:
2987 if (tc0->flags & TCP_CONN_FINPNDG)
2989 /* If data is outstanding, stay in FIN_WAIT_1 and try to finish
2990 * sending it. Since we already received a fin, do not wait
2992 tc0->flags |= TCP_CONN_FINRCVD;
2993 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
2997 tcp_connection_set_state (tc0, TCP_STATE_CLOSING);
2998 tcp_program_ack (wrk, tc0);
2999 /* Wait for ACK for our FIN but not forever */
3000 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
3003 case TCP_STATE_FIN_WAIT_2:
3004 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
3006 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
3007 tcp_connection_timers_reset (tc0);
3008 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
3009 tcp_program_ack (wrk, tc0);
3010 session_transport_closed_notify (&tc0->connection);
3012 case TCP_STATE_TIME_WAIT:
3013 /* Remain in the TIME-WAIT state. Restart the time-wait
3016 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
3019 error0 = TCP_ERROR_FIN_RCVD;
3023 tcp_inc_counter (rcv_process, error0, 1);
3024 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3026 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3027 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
3031 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
3033 tcp_inc_counter (rcv_process, TCP_ERROR_MSG_QUEUE_FULL, errors);
3034 tcp_handle_postponed_dequeues (wrk);
3035 tcp_handle_disconnects (wrk);
3036 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3038 return from_frame->n_vectors;
3041 VLIB_NODE_FN (tcp4_rcv_process_node) (vlib_main_t * vm,
3042 vlib_node_runtime_t * node,
3043 vlib_frame_t * from_frame)
3045 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3048 VLIB_NODE_FN (tcp6_rcv_process_node) (vlib_main_t * vm,
3049 vlib_node_runtime_t * node,
3050 vlib_frame_t * from_frame)
3052 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3056 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
3058 .name = "tcp4-rcv-process",
3059 /* Takes a vector of packets. */
3060 .vector_size = sizeof (u32),
3061 .n_errors = TCP_N_ERROR,
3062 .error_strings = tcp_error_strings,
3063 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3066 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3067 foreach_tcp_state_next
3070 .format_trace = format_tcp_rx_trace_short,
3075 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
3077 .name = "tcp6-rcv-process",
3078 /* Takes a vector of packets. */
3079 .vector_size = sizeof (u32),
3080 .n_errors = TCP_N_ERROR,
3081 .error_strings = tcp_error_strings,
3082 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3085 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3086 foreach_tcp_state_next
3089 .format_trace = format_tcp_rx_trace_short,
3094 * LISTEN state processing as per RFC 793 p. 65
3097 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3098 vlib_frame_t * from_frame, int is_ip4)
3100 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3101 u32 my_thread_index = vm->thread_index;
3103 from = first_buffer = vlib_frame_vector_args (from_frame);
3104 n_left_from = from_frame->n_vectors;
3106 while (n_left_from > 0)
3111 tcp_header_t *th0 = 0;
3112 tcp_connection_t *lc0;
3115 tcp_connection_t *child0;
3116 u32 error0 = TCP_ERROR_NONE;
3122 b0 = vlib_get_buffer (vm, bi0);
3123 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3127 ip40 = vlib_buffer_get_current (b0);
3128 th0 = ip4_next_header (ip40);
3132 ip60 = vlib_buffer_get_current (b0);
3133 th0 = ip6_next_header (ip60);
3136 /* Create child session. For syn-flood protection use filter */
3138 /* 1. first check for an RST: handled in dispatch */
3139 /* if (tcp_rst (th0))
3143 /* 2. second check for an ACK: handled in dispatch */
3144 /* if (tcp_ack (th0))
3146 tcp_send_reset (b0, is_ip4);
3151 /* 3. check for a SYN (did that already) */
3153 /* Make sure connection wasn't just created */
3154 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3156 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3158 error0 = TCP_ERROR_CREATE_EXISTS;
3162 /* Create child session and send SYN-ACK */
3163 child0 = tcp_connection_alloc (my_thread_index);
3164 child0->c_lcl_port = th0->dst_port;
3165 child0->c_rmt_port = th0->src_port;
3166 child0->c_is_ip4 = is_ip4;
3167 child0->state = TCP_STATE_SYN_RCVD;
3168 child0->c_fib_index = lc0->c_fib_index;
3172 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3173 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3177 clib_memcpy_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3178 sizeof (ip6_address_t));
3179 clib_memcpy_fast (&child0->c_rmt_ip6, &ip60->src_address,
3180 sizeof (ip6_address_t));
3183 if (tcp_options_parse (th0, &child0->rcv_opts, 1))
3185 error0 = TCP_ERROR_OPTIONS;
3186 tcp_connection_free (child0);
3190 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3191 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3192 child0->rcv_las = child0->rcv_nxt;
3193 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3195 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3196 * segments are used to initialize PAWS. */
3197 if (tcp_opts_tstamp (&child0->rcv_opts))
3199 child0->tsval_recent = child0->rcv_opts.tsval;
3200 child0->tsval_recent_age = tcp_time_now ();
3203 if (tcp_opts_wscale (&child0->rcv_opts))
3204 child0->snd_wscale = child0->rcv_opts.wscale;
3206 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3207 << child0->snd_wscale;
3208 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3209 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3211 tcp_connection_init_vars (child0);
3212 child0->rto = TCP_RTO_MIN;
3214 if (session_stream_accept (&child0->connection, lc0->c_s_index,
3215 lc0->c_thread_index, 0 /* notify */ ))
3217 tcp_connection_cleanup (child0);
3218 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3222 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
3223 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3224 tcp_send_synack (child0);
3225 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
3229 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3231 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3232 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3233 clib_memcpy_fast (&t0->tcp_connection, lc0,
3234 sizeof (t0->tcp_connection));
3237 n_syns += (error0 == TCP_ERROR_NONE);
3240 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3241 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3243 return from_frame->n_vectors;
3246 VLIB_NODE_FN (tcp4_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3247 vlib_frame_t * from_frame)
3249 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3252 VLIB_NODE_FN (tcp6_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3253 vlib_frame_t * from_frame)
3255 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3259 VLIB_REGISTER_NODE (tcp4_listen_node) =
3261 .name = "tcp4-listen",
3262 /* Takes a vector of packets. */
3263 .vector_size = sizeof (u32),
3264 .n_errors = TCP_N_ERROR,
3265 .error_strings = tcp_error_strings,
3266 .n_next_nodes = TCP_LISTEN_N_NEXT,
3269 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3270 foreach_tcp_state_next
3273 .format_trace = format_tcp_rx_trace_short,
3278 VLIB_REGISTER_NODE (tcp6_listen_node) =
3280 .name = "tcp6-listen",
3281 /* Takes a vector of packets. */
3282 .vector_size = sizeof (u32),
3283 .n_errors = TCP_N_ERROR,
3284 .error_strings = tcp_error_strings,
3285 .n_next_nodes = TCP_LISTEN_N_NEXT,
3288 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3289 foreach_tcp_state_next
3292 .format_trace = format_tcp_rx_trace_short,
3296 typedef enum _tcp_input_next
3298 TCP_INPUT_NEXT_DROP,
3299 TCP_INPUT_NEXT_LISTEN,
3300 TCP_INPUT_NEXT_RCV_PROCESS,
3301 TCP_INPUT_NEXT_SYN_SENT,
3302 TCP_INPUT_NEXT_ESTABLISHED,
3303 TCP_INPUT_NEXT_RESET,
3304 TCP_INPUT_NEXT_PUNT,
3308 #define foreach_tcp4_input_next \
3309 _ (DROP, "ip4-drop") \
3310 _ (LISTEN, "tcp4-listen") \
3311 _ (RCV_PROCESS, "tcp4-rcv-process") \
3312 _ (SYN_SENT, "tcp4-syn-sent") \
3313 _ (ESTABLISHED, "tcp4-established") \
3314 _ (RESET, "tcp4-reset") \
3315 _ (PUNT, "ip4-punt")
3317 #define foreach_tcp6_input_next \
3318 _ (DROP, "ip6-drop") \
3319 _ (LISTEN, "tcp6-listen") \
3320 _ (RCV_PROCESS, "tcp6-rcv-process") \
3321 _ (SYN_SENT, "tcp6-syn-sent") \
3322 _ (ESTABLISHED, "tcp6-established") \
3323 _ (RESET, "tcp6-reset") \
3324 _ (PUNT, "ip6-punt")
3326 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3329 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3330 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3332 tcp_connection_t *tc;
3337 for (i = 0; i < n_bufs; i++)
3339 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3341 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3342 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3344 tcp = vlib_buffer_get_current (bs[i]);
3345 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3351 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3353 if (*error == TCP_ERROR_FILTERED || *error == TCP_ERROR_WRONG_THREAD)
3355 *next = TCP_INPUT_NEXT_DROP;
3357 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3359 *next = TCP_INPUT_NEXT_PUNT;
3360 *error = TCP_ERROR_PUNT;
3364 *next = TCP_INPUT_NEXT_RESET;
3365 *error = TCP_ERROR_NO_LISTENER;
3369 always_inline tcp_connection_t *
3370 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3371 u8 is_ip4, u8 is_nolookup)
3373 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3374 int n_advance_bytes, n_data_bytes;
3375 transport_connection_t *tc;
3381 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3382 int ip_hdr_bytes = ip4_header_bytes (ip4);
3383 if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
3385 *error = TCP_ERROR_LENGTH;
3388 tcp = ip4_next_header (ip4);
3389 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3390 n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
3391 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3393 /* Length check. Checksum computed by ipx_local no need to compute again */
3394 if (PREDICT_FALSE (n_data_bytes < 0))
3396 *error = TCP_ERROR_LENGTH;
3401 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3402 &ip4->src_address, tcp->dst_port,
3404 TRANSPORT_PROTO_TCP, thread_index,
3409 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3410 if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
3412 *error = TCP_ERROR_LENGTH;
3415 tcp = ip6_next_header (ip6);
3416 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3417 n_advance_bytes = tcp_header_bytes (tcp);
3418 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3420 n_advance_bytes += sizeof (ip6[0]);
3422 if (PREDICT_FALSE (n_data_bytes < 0))
3424 *error = TCP_ERROR_LENGTH;
3431 (ip6_address_is_link_local_unicast (&ip6->dst_address)))
3433 ip4_main_t *im = &ip4_main;
3434 fib_index = vec_elt (im->fib_index_by_sw_if_index,
3435 vnet_buffer (b)->sw_if_index[VLIB_RX]);
3438 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3440 tcp->dst_port, tcp->src_port,
3441 TRANSPORT_PROTO_TCP,
3442 thread_index, &result);
3448 (transport_connection_t *) tcp_connection_get (vnet_buffer (b)->
3449 tcp.connection_index,
3452 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3453 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3454 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3455 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3456 vnet_buffer (b)->tcp.seq_end = vnet_buffer (b)->tcp.seq_number
3458 vnet_buffer (b)->tcp.flags = 0;
3460 *error = result ? TCP_ERROR_NONE + result : *error;
3462 return tcp_get_connection_from_transport (tc);
3466 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3467 vlib_buffer_t * b, u16 * next, u32 * error)
3472 tcp = tcp_buffer_hdr (b);
3473 flags = tcp->flags & filter_flags;
3474 *next = tm->dispatch_table[tc->state][flags].next;
3475 *error = tm->dispatch_table[tc->state][flags].error;
3477 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3478 || *next == TCP_INPUT_NEXT_RESET))
3480 /* Overload tcp flags to store state */
3481 tcp_state_t state = tc->state;
3482 vnet_buffer (b)->tcp.flags = tc->state;
3484 if (*error == TCP_ERROR_DISPATCH)
3485 clib_warning ("tcp conn %u disp error state %U flags %U",
3486 tc->c_c_index, format_tcp_state, state,
3487 format_tcp_flags, (int) flags);
3492 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3493 vlib_frame_t * frame, int is_ip4, u8 is_nolookup)
3495 u32 n_left_from, *from, thread_index = vm->thread_index;
3496 tcp_main_t *tm = vnet_get_tcp_main ();
3497 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3498 u16 nexts[VLIB_FRAME_SIZE], *next;
3500 tcp_set_time_now (tcp_get_worker (thread_index));
3502 from = vlib_frame_vector_args (frame);
3503 n_left_from = frame->n_vectors;
3504 vlib_get_buffers (vm, from, bufs, n_left_from);
3509 while (n_left_from >= 4)
3511 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3512 tcp_connection_t *tc0, *tc1;
3515 vlib_prefetch_buffer_header (b[2], STORE);
3516 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3518 vlib_prefetch_buffer_header (b[3], STORE);
3519 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3522 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3524 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3526 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4,
3529 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3531 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3532 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3534 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3535 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3537 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3538 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3542 if (PREDICT_TRUE (tc0 != 0))
3544 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3545 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3546 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3549 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3551 if (PREDICT_TRUE (tc1 != 0))
3553 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3554 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3555 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3558 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3565 while (n_left_from > 0)
3567 tcp_connection_t *tc0;
3568 u32 error0 = TCP_ERROR_NO_LISTENER;
3570 if (n_left_from > 1)
3572 vlib_prefetch_buffer_header (b[1], STORE);
3573 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3576 next[0] = TCP_INPUT_NEXT_DROP;
3577 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3579 if (PREDICT_TRUE (tc0 != 0))
3581 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3582 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3583 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3586 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3593 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3594 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3596 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3597 return frame->n_vectors;
3600 VLIB_NODE_FN (tcp4_input_nolookup_node) (vlib_main_t * vm,
3601 vlib_node_runtime_t * node,
3602 vlib_frame_t * from_frame)
3604 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ,
3605 1 /* is_nolookup */ );
3608 VLIB_NODE_FN (tcp6_input_nolookup_node) (vlib_main_t * vm,
3609 vlib_node_runtime_t * node,
3610 vlib_frame_t * from_frame)
3612 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3613 1 /* is_nolookup */ );
3617 VLIB_REGISTER_NODE (tcp4_input_nolookup_node) =
3619 .name = "tcp4-input-nolookup",
3620 /* Takes a vector of packets. */
3621 .vector_size = sizeof (u32),
3622 .n_errors = TCP_N_ERROR,
3623 .error_strings = tcp_error_strings,
3624 .n_next_nodes = TCP_INPUT_N_NEXT,
3627 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3628 foreach_tcp4_input_next
3631 .format_buffer = format_tcp_header,
3632 .format_trace = format_tcp_rx_trace,
3637 VLIB_REGISTER_NODE (tcp6_input_nolookup_node) =
3639 .name = "tcp6-input-nolookup",
3640 /* Takes a vector of packets. */
3641 .vector_size = sizeof (u32),
3642 .n_errors = TCP_N_ERROR,
3643 .error_strings = tcp_error_strings,
3644 .n_next_nodes = TCP_INPUT_N_NEXT,
3647 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3648 foreach_tcp6_input_next
3651 .format_buffer = format_tcp_header,
3652 .format_trace = format_tcp_rx_trace,
3656 VLIB_NODE_FN (tcp4_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3657 vlib_frame_t * from_frame)
3659 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ,
3660 0 /* is_nolookup */ );
3663 VLIB_NODE_FN (tcp6_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3664 vlib_frame_t * from_frame)
3666 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3667 0 /* is_nolookup */ );
3671 VLIB_REGISTER_NODE (tcp4_input_node) =
3673 .name = "tcp4-input",
3674 /* Takes a vector of packets. */
3675 .vector_size = sizeof (u32),
3676 .n_errors = TCP_N_ERROR,
3677 .error_strings = tcp_error_strings,
3678 .n_next_nodes = TCP_INPUT_N_NEXT,
3681 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3682 foreach_tcp4_input_next
3685 .format_buffer = format_tcp_header,
3686 .format_trace = format_tcp_rx_trace,
3691 VLIB_REGISTER_NODE (tcp6_input_node) =
3693 .name = "tcp6-input",
3694 /* Takes a vector of packets. */
3695 .vector_size = sizeof (u32),
3696 .n_errors = TCP_N_ERROR,
3697 .error_strings = tcp_error_strings,
3698 .n_next_nodes = TCP_INPUT_N_NEXT,
3701 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3702 foreach_tcp6_input_next
3705 .format_buffer = format_tcp_header,
3706 .format_trace = format_tcp_rx_trace,
3710 #ifndef CLIB_MARCH_VARIANT
3712 tcp_dispatch_table_init (tcp_main_t * tm)
3715 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3716 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3718 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3719 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3722 #define _(t,f,n,e) \
3724 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3725 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3728 /* RFC 793: In LISTEN if RST drop and if ACK return RST */
3729 _(LISTEN, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3730 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_ACK_INVALID);
3731 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_INVALID_CONNECTION);
3732 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3733 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3734 TCP_ERROR_ACK_INVALID);
3735 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3736 TCP_ERROR_SEGMENT_INVALID);
3737 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3738 TCP_ERROR_SEGMENT_INVALID);
3739 _(LISTEN, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3740 TCP_ERROR_INVALID_CONNECTION);
3741 _(LISTEN, TCP_FLAG_FIN, TCP_INPUT_NEXT_RESET, TCP_ERROR_SEGMENT_INVALID);
3742 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3743 TCP_ERROR_SEGMENT_INVALID);
3744 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3745 TCP_ERROR_SEGMENT_INVALID);
3746 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3748 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_DROP,
3749 TCP_ERROR_SEGMENT_INVALID);
3750 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3751 TCP_ERROR_SEGMENT_INVALID);
3752 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3753 TCP_ERROR_SEGMENT_INVALID);
3754 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3755 TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3756 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3757 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3758 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3759 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3761 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3762 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3764 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3766 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3767 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3768 _(SYN_RCVD, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3769 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3771 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3773 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3774 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3775 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3777 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3778 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3779 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3780 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3781 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3782 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3783 _(SYN_RCVD, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3784 /* SYN-ACK for a SYN */
3785 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3787 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3788 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3789 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3791 _(SYN_SENT, TCP_FLAG_FIN, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3792 _(SYN_SENT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3794 /* ACK for for established connection -> tcp-established. */
3795 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3796 /* FIN for for established connection -> tcp-established. */
3797 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3798 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3800 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3802 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3803 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3804 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED,
3806 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3807 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3808 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3809 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3810 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3811 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3812 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3813 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3815 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3816 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3818 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3820 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3821 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3822 _(ESTABLISHED, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3823 /* ACK or FIN-ACK to our FIN */
3824 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3825 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3827 /* FIN in reply to our FIN from the other side */
3828 _(FIN_WAIT_1, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3829 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3830 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3832 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3833 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3834 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3835 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3836 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3837 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3838 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3840 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3841 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3842 _(FIN_WAIT_1, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3843 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3845 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3847 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3848 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3849 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3850 _(FIN_WAIT_1, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3852 _(CLOSING, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3853 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3854 _(CLOSING, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3855 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3857 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3859 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3860 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3861 _(CLOSING, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3862 _(CLOSING, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3864 _(CLOSING, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3865 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3867 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3869 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3870 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3871 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3873 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3874 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3875 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3876 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3877 /* FIN confirming that the peer (app) has closed */
3878 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3879 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3880 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3882 _(FIN_WAIT_2, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3883 _(FIN_WAIT_2, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3885 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3886 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3888 _(CLOSE_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3889 _(CLOSE_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3891 _(LAST_ACK, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3892 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3893 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3894 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3896 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3898 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3899 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3900 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3902 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3903 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3904 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3905 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3906 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3907 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3908 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3909 _(LAST_ACK, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3911 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3912 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3914 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3916 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3917 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3918 _(TIME_WAIT, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3919 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3920 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3922 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3923 _(TIME_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3925 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3926 /* RFC793 CLOSED: An incoming segment containing a RST is discarded. An
3927 * incoming segment not containing a RST causes a RST to be sent in
3929 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3930 _(CLOSED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3931 TCP_ERROR_CONNECTION_CLOSED);
3932 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3933 _(CLOSED, TCP_FLAG_SYN, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3934 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3939 static clib_error_t *
3940 tcp_input_init (vlib_main_t * vm)
3942 clib_error_t *error = 0;
3943 tcp_main_t *tm = vnet_get_tcp_main ();
3945 if ((error = vlib_call_init_function (vm, tcp_init)))
3948 /* Initialize dispatch table. */
3949 tcp_dispatch_table_init (tm);
3954 VLIB_INIT_FUNCTION (tcp_input_init);
3956 #endif /* CLIB_MARCH_VARIANT */
3959 * fd.io coding-style-patch-verification: ON
3962 * eval: (c-set-style "gnu")