2 * Copyright (c) 2016 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
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 \
82 vlib_node_registration_t tcp4_established_node;
83 vlib_node_registration_t tcp6_established_node;
86 * Validate segment sequence number. As per RFC793:
88 * Segment Receive Test
90 * ------- ------- -------------------------------------------
91 * 0 0 SEG.SEQ = RCV.NXT
92 * 0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
94 * >0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
95 * or RCV.NXT =< SEG.SEQ+SEG.LEN-1 < RCV.NXT+RCV.WND
97 * This ultimately consists in checking if segment falls within the window.
98 * The one important difference compared to RFC793 is that we use rcv_las,
99 * or the rcv_nxt at last ack sent instead of rcv_nxt since that's the
100 * peer's reference when computing our receive window.
103 * seq_leq (end_seq, tc->rcv_las + tc->rcv_wnd) && seq_geq (seq, tc->rcv_las)
104 * however, is too strict when we have retransmits. Instead we just check that
105 * the seq is not beyond the right edge and that the end of the segment is not
106 * less than the left edge.
108 * N.B. rcv_nxt and rcv_wnd are both updated in this node if acks are sent, so
109 * use rcv_nxt in the right edge window test instead of rcv_las.
113 tcp_segment_in_rcv_wnd (tcp_connection_t * tc, u32 seq, u32 end_seq)
115 return (seq_geq (end_seq, tc->rcv_las)
116 && seq_leq (seq, tc->rcv_nxt + tc->rcv_wnd));
120 * Parse TCP header options.
122 * @param th TCP header
123 * @param to TCP options data structure to be populated
124 * @param is_syn set if packet is syn
125 * @return -1 if parsing failed
128 tcp_options_parse (tcp_header_t * th, tcp_options_t * to, u8 is_syn)
131 u8 opt_len, opts_len, kind;
135 opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t);
136 data = (const u8 *) (th + 1);
138 /* Zero out all flags but those set in SYN */
139 to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE
140 | TCP_OPTS_FLAG_TSTAMP | TCP_OPTION_MSS);
142 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
146 /* Get options length */
147 if (kind == TCP_OPTION_EOL)
149 else if (kind == TCP_OPTION_NOOP)
161 /* weird option length */
162 if (opt_len < 2 || opt_len > opts_len)
172 if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
174 to->flags |= TCP_OPTS_FLAG_MSS;
175 to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
178 case TCP_OPTION_WINDOW_SCALE:
181 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
183 to->flags |= TCP_OPTS_FLAG_WSCALE;
184 to->wscale = data[2];
185 if (to->wscale > TCP_MAX_WND_SCALE)
187 clib_warning ("Illegal window scaling value: %d",
189 to->wscale = TCP_MAX_WND_SCALE;
193 case TCP_OPTION_TIMESTAMP:
195 to->flags |= TCP_OPTS_FLAG_TSTAMP;
196 if ((to->flags & TCP_OPTS_FLAG_TSTAMP)
197 && opt_len == TCP_OPTION_LEN_TIMESTAMP)
199 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
200 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
203 case TCP_OPTION_SACK_PERMITTED:
206 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
207 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
209 case TCP_OPTION_SACK_BLOCK:
210 /* If SACK permitted was not advertised or a SYN, break */
211 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
214 /* If too short or not correctly formatted, break */
215 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
218 to->flags |= TCP_OPTS_FLAG_SACK;
219 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
220 vec_reset_length (to->sacks);
221 for (j = 0; j < to->n_sack_blocks; j++)
223 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 8 * j));
224 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 8 * j));
225 vec_add1 (to->sacks, b);
229 /* Nothing to see here */
237 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
238 * timestamp to echo and it's less than tsval_recent, drop segment
239 * but still send an ACK in order to retain TCP's mechanism for detecting
240 * and recovering from half-open connections
242 * Or at least that's what the theory says. It seems that this might not work
243 * very well with packet reordering and fast retransmit. XXX
246 tcp_segment_check_paws (tcp_connection_t * tc)
248 return tcp_opts_tstamp (&tc->rcv_opts) && tc->tsval_recent
249 && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent);
253 * Update tsval recent
256 tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
259 * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
260 * of an incoming segment:
261 * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
262 * then the TSval from the segment is copied to TS.Recent;
263 * otherwise, the TSval is ignored.
265 if (tcp_opts_tstamp (&tc->rcv_opts) && seq_leq (seq, tc->rcv_las)
266 && seq_leq (tc->rcv_las, seq_end))
268 ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval));
269 tc->tsval_recent = tc->rcv_opts.tsval;
270 tc->tsval_recent_age = tcp_time_now_w_thread (tc->c_thread_index);
275 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
277 * It first verifies if segment has a wrapped sequence number (PAWS) and then
278 * does the processing associated to the first four steps (ignoring security
279 * and precedence): sequence number, rst bit and syn bit checks.
281 * @return 0 if segments passes validation.
284 tcp_segment_validate (tcp_worker_ctx_t * wrk, tcp_connection_t * tc0,
285 vlib_buffer_t * b0, tcp_header_t * th0, u32 * error0)
287 /* We could get a burst of RSTs interleaved with acks */
288 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
290 tcp_send_reset (tc0);
291 *error0 = TCP_ERROR_CONNECTION_CLOSED;
295 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
297 *error0 = TCP_ERROR_SEGMENT_INVALID;
301 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts, 0)))
303 *error0 = TCP_ERROR_OPTIONS;
307 if (PREDICT_FALSE (tcp_segment_check_paws (tc0)))
309 *error0 = TCP_ERROR_PAWS;
311 clib_warning ("paws failed\n%U", format_tcp_connection, tc0, 2);
312 TCP_EVT_DBG (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
313 vnet_buffer (b0)->tcp.seq_end);
315 /* If it just so happens that a segment updates tsval_recent for a
316 * segment over 24 days old, invalidate tsval_recent. */
317 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
318 tcp_time_now_w_thread (tc0->c_thread_index)))
320 /* Age isn't reset until we get a valid tsval (bsd inspired) */
321 tc0->tsval_recent = 0;
322 clib_warning ("paws failed - really old segment. REALLY?");
326 /* Drop after ack if not rst */
329 tcp_program_ack (wrk, tc0);
330 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
336 /* 1st: check sequence number */
337 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
338 vnet_buffer (b0)->tcp.seq_end))
340 *error0 = TCP_ERROR_RCV_WND;
341 /* If our window is 0 and the packet is in sequence, let it pass
342 * through for ack processing. It should be dropped later. */
343 if (!(tc0->rcv_wnd == 0
344 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number))
346 /* If not RST, send dup ack */
349 tcp_program_dupack (wrk, tc0);
350 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
356 /* 2nd: check the RST bit */
357 if (PREDICT_FALSE (tcp_rst (th0)))
359 tcp_connection_reset (tc0);
360 *error0 = TCP_ERROR_RST_RCVD;
364 /* 3rd: check security and precedence (skip) */
366 /* 4th: check the SYN bit */
367 if (PREDICT_FALSE (tcp_syn (th0)))
369 /* TODO implement RFC 5961 */
370 if (tc0->state == TCP_STATE_SYN_RCVD)
372 tcp_options_parse (th0, &tc0->rcv_opts, 1);
373 tcp_send_synack (tc0);
374 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0, 0);
378 tcp_program_ack (wrk, tc0);
379 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, tc0);
384 /* If segment in window, save timestamp */
385 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
386 vnet_buffer (b0)->tcp.seq_end);
394 tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0)
396 /* SND.UNA =< SEG.ACK =< SND.NXT */
397 return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number)
398 && seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt));
402 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
404 * Note that although the original article, srtt and rttvar are scaled
405 * to minimize round-off errors, here we don't. Instead, we rely on
406 * better precision time measurements.
408 * TODO support us rtt resolution
411 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
417 err = mrtt - tc->srtt;
419 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
420 * The increase should be bound */
421 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
422 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
423 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
427 /* First measurement. */
429 tc->rttvar = mrtt >> 1;
434 tcp_update_rto (tcp_connection_t * tc)
436 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
437 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
441 * Update RTT estimate and RTO timer
443 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
444 * timing. Middle boxes are known to fiddle with TCP options so we
445 * should give higher priority to ACK timing.
447 * This should be called only if previously sent bytes have been acked.
449 * return 1 if valid rtt 0 otherwise
452 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
456 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
457 * RTT because they're ambiguous. */
458 if (tcp_in_cong_recovery (tc) || tc->sack_sb.sacked_bytes)
460 if (tcp_in_recovery (tc))
465 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
467 f64 sample = tcp_time_now_us (tc->c_thread_index) - tc->rtt_ts;
468 tc->mrtt_us = tc->mrtt_us + (sample - tc->mrtt_us) * 0.125;
469 mrtt = clib_max ((u32) (sample * THZ), 1);
470 /* Allow measuring of a new RTT */
473 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
474 * snd_una, i.e., the left side of the send window:
475 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
476 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
478 u32 now = tcp_time_now_w_thread (tc->c_thread_index);
479 mrtt = clib_max (now - tc->rcv_opts.tsecr, 1);
482 /* Ignore dubious measurements */
483 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
486 tcp_estimate_rtt (tc, mrtt);
490 /* If we got here something must've been ACKed so make sure boff is 0,
491 * even if mrtt is not valid since we update the rto lower */
499 tcp_estimate_initial_rtt (tcp_connection_t * tc)
501 u8 thread_index = vlib_num_workers ()? 1 : 0;
506 tc->mrtt_us = tcp_time_now_us (thread_index) - tc->rtt_ts;
507 mrtt = clib_max ((u32) (tc->mrtt_us * THZ), 1);
512 mrtt = tcp_time_now_w_thread (thread_index) - tc->rcv_opts.tsecr;
513 mrtt = clib_max (mrtt, 1);
514 tc->mrtt_us = (f64) mrtt *TCP_TICK;
517 if (mrtt > 0 && mrtt < TCP_RTT_MAX)
518 tcp_estimate_rtt (tc, mrtt);
522 * Dequeue bytes for connections that have received acks in last burst
525 tcp_handle_postponed_dequeues (tcp_worker_ctx_t * wrk)
527 u32 thread_index = wrk->vm->thread_index;
528 u32 *pending_deq_acked;
529 tcp_connection_t *tc;
532 if (!vec_len (wrk->pending_deq_acked))
535 pending_deq_acked = wrk->pending_deq_acked;
536 for (i = 0; i < vec_len (pending_deq_acked); i++)
538 tc = tcp_connection_get (pending_deq_acked[i], thread_index);
539 tc->flags &= ~TCP_CONN_DEQ_PENDING;
541 if (PREDICT_FALSE (!tc->burst_acked))
544 /* Dequeue the newly ACKed bytes */
545 stream_session_dequeue_drop (&tc->connection, tc->burst_acked);
547 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
549 /* If everything has been acked, stop retransmit timer
550 * otherwise update. */
551 tcp_retransmit_timer_update (tc);
553 /* If not congested, update pacer based on our new
555 if (!tcp_in_fastrecovery (tc))
556 tcp_connection_tx_pacer_update (tc);
558 _vec_len (wrk->pending_deq_acked) = 0;
562 tcp_program_dequeue (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
564 if (!(tc->flags & TCP_CONN_DEQ_PENDING))
566 vec_add1 (wrk->pending_deq_acked, tc->c_c_index);
567 tc->flags |= TCP_CONN_DEQ_PENDING;
569 tc->burst_acked += tc->bytes_acked + tc->sack_sb.snd_una_adv;
573 * Check if duplicate ack as per RFC5681 Sec. 2
576 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
579 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
580 && seq_gt (tc->snd_una_max, tc->snd_una)
581 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
582 && (prev_snd_wnd == tc->snd_wnd));
586 * Checks if ack is a congestion control event.
589 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
590 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
592 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
593 * defined to be 'duplicate' */
594 *is_dack = tc->sack_sb.last_sacked_bytes
595 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
597 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
601 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
603 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
604 return hole - sb->holes;
608 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
610 return hole->end - hole->start;
613 sack_scoreboard_hole_t *
614 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
616 if (index != TCP_INVALID_SACK_HOLE_INDEX)
617 return pool_elt_at_index (sb->holes, index);
621 sack_scoreboard_hole_t *
622 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
624 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
625 return pool_elt_at_index (sb->holes, hole->next);
629 sack_scoreboard_hole_t *
630 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
632 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
633 return pool_elt_at_index (sb->holes, hole->prev);
637 sack_scoreboard_hole_t *
638 scoreboard_first_hole (sack_scoreboard_t * sb)
640 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
641 return pool_elt_at_index (sb->holes, sb->head);
645 sack_scoreboard_hole_t *
646 scoreboard_last_hole (sack_scoreboard_t * sb)
648 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
649 return pool_elt_at_index (sb->holes, sb->tail);
654 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
656 sack_scoreboard_hole_t *next, *prev;
658 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
660 next = pool_elt_at_index (sb->holes, hole->next);
661 next->prev = hole->prev;
665 sb->tail = hole->prev;
668 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
670 prev = pool_elt_at_index (sb->holes, hole->prev);
671 prev->next = hole->next;
675 sb->head = hole->next;
678 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
679 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
681 /* Poison the entry */
683 clib_memset (hole, 0xfe, sizeof (*hole));
685 pool_put (sb->holes, hole);
688 static sack_scoreboard_hole_t *
689 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
692 sack_scoreboard_hole_t *hole, *next, *prev;
695 pool_get (sb->holes, hole);
696 clib_memset (hole, 0, sizeof (*hole));
700 hole_index = scoreboard_hole_index (sb, hole);
702 prev = scoreboard_get_hole (sb, prev_index);
705 hole->prev = prev_index;
706 hole->next = prev->next;
708 if ((next = scoreboard_next_hole (sb, hole)))
709 next->prev = hole_index;
711 sb->tail = hole_index;
713 prev->next = hole_index;
717 sb->head = hole_index;
718 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
719 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
726 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
728 sack_scoreboard_hole_t *left, *right;
729 u32 bytes = 0, blks = 0;
732 sb->sacked_bytes = 0;
733 left = scoreboard_last_hole (sb);
737 if (seq_gt (sb->high_sacked, left->end))
739 bytes = sb->high_sacked - left->end;
743 while ((right = left)
744 && bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
745 && blks < TCP_DUPACK_THRESHOLD
746 /* left not updated if above conditions fail */
747 && (left = scoreboard_prev_hole (sb, right)))
749 bytes += right->start - left->end;
753 /* left is first lost */
758 sb->lost_bytes += scoreboard_hole_bytes (right);
760 left = scoreboard_prev_hole (sb, right);
762 bytes += right->start - left->end;
764 while ((right = left));
767 sb->sacked_bytes = bytes;
771 * Figure out the next hole to retransmit
773 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
775 sack_scoreboard_hole_t *
776 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
777 sack_scoreboard_hole_t * start,
778 u8 have_unsent, u8 * can_rescue, u8 * snd_limited)
780 sack_scoreboard_hole_t *hole = 0;
782 hole = start ? start : scoreboard_first_hole (sb);
783 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
784 hole = scoreboard_next_hole (sb, hole);
786 /* Nothing, return */
789 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
793 /* Rule (1): if higher than rxt, less than high_sacked and lost */
794 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
796 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
800 /* Rule (2): available unsent data */
803 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
806 /* Rule (3): if hole not lost */
807 else if (seq_lt (hole->start, sb->high_sacked))
810 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
812 /* Rule (4): if hole beyond high_sacked */
815 ASSERT (seq_geq (hole->start, sb->high_sacked));
818 /* HighRxt MUST NOT be updated */
823 if (hole && seq_lt (sb->high_rxt, hole->start))
824 sb->high_rxt = hole->start;
830 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 snd_una)
832 sack_scoreboard_hole_t *hole;
833 hole = scoreboard_first_hole (sb);
836 snd_una = seq_gt (snd_una, hole->start) ? snd_una : hole->start;
837 sb->cur_rxt_hole = sb->head;
839 sb->high_rxt = snd_una;
840 sb->rescue_rxt = snd_una - 1;
844 scoreboard_init (sack_scoreboard_t * sb)
846 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
847 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
848 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
852 scoreboard_clear (sack_scoreboard_t * sb)
854 sack_scoreboard_hole_t *hole;
855 while ((hole = scoreboard_first_hole (sb)))
857 scoreboard_remove_hole (sb, hole);
859 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
860 ASSERT (pool_elts (sb->holes) == 0);
861 sb->sacked_bytes = 0;
862 sb->last_sacked_bytes = 0;
863 sb->last_bytes_delivered = 0;
868 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
872 * Test that scoreboard is sane after recovery
874 * Returns 1 if scoreboard is empty or if first hole beyond
878 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
880 sack_scoreboard_hole_t *hole;
881 hole = scoreboard_first_hole (&tc->sack_sb);
882 return (!hole || (seq_geq (hole->start, tc->snd_una)
883 && seq_lt (hole->end, tc->snd_una_max)));
887 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
889 sack_scoreboard_t *sb = &tc->sack_sb;
890 sack_block_t *blk, tmp;
891 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
892 u32 blk_index = 0, old_sacked_bytes, hole_index;
895 sb->last_sacked_bytes = 0;
896 sb->last_bytes_delivered = 0;
899 if (!tcp_opts_sack (&tc->rcv_opts)
900 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
903 old_sacked_bytes = sb->sacked_bytes;
905 /* Remove invalid blocks */
906 blk = tc->rcv_opts.sacks;
907 while (blk < vec_end (tc->rcv_opts.sacks))
909 if (seq_lt (blk->start, blk->end)
910 && seq_gt (blk->start, tc->snd_una)
911 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_una_max))
916 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
919 /* Add block for cumulative ack */
920 if (seq_gt (ack, tc->snd_una))
922 tmp.start = tc->snd_una;
924 vec_add1 (tc->rcv_opts.sacks, tmp);
927 if (vec_len (tc->rcv_opts.sacks) == 0)
930 tcp_scoreboard_trace_add (tc, ack);
932 /* Make sure blocks are ordered */
933 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
934 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
935 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
937 tmp = tc->rcv_opts.sacks[i];
938 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
939 tc->rcv_opts.sacks[j] = tmp;
942 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
944 /* If no holes, insert the first that covers all outstanding bytes */
945 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
946 tc->snd_una, tc->snd_una_max);
947 sb->tail = scoreboard_hole_index (sb, last_hole);
948 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
949 sb->high_sacked = tmp.end;
953 /* If we have holes but snd_una_max is beyond the last hole, update
955 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
956 last_hole = scoreboard_last_hole (sb);
957 if (seq_gt (tc->snd_una_max, last_hole->end))
959 if (seq_geq (last_hole->start, sb->high_sacked))
961 last_hole->end = tc->snd_una_max;
963 /* New hole after high sacked block */
964 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
966 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
970 /* Keep track of max byte sacked for when the last hole
972 if (seq_gt (tmp.end, sb->high_sacked))
973 sb->high_sacked = tmp.end;
976 /* Walk the holes with the SACK blocks */
977 hole = pool_elt_at_index (sb->holes, sb->head);
978 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
980 blk = &tc->rcv_opts.sacks[blk_index];
981 if (seq_leq (blk->start, hole->start))
983 /* Block covers hole. Remove hole */
984 if (seq_geq (blk->end, hole->end))
986 next_hole = scoreboard_next_hole (sb, hole);
988 /* Byte accounting: snd_una needs to be advanced */
993 if (seq_lt (ack, next_hole->start))
994 sb->snd_una_adv = next_hole->start - ack;
995 sb->last_bytes_delivered +=
996 next_hole->start - hole->end;
1000 ASSERT (seq_geq (sb->high_sacked, ack));
1001 sb->snd_una_adv = sb->high_sacked - ack;
1002 sb->last_bytes_delivered += sb->high_sacked - hole->end;
1006 scoreboard_remove_hole (sb, hole);
1009 /* Partial 'head' overlap */
1012 if (seq_gt (blk->end, hole->start))
1014 hole->start = blk->end;
1021 /* Hole must be split */
1022 if (seq_lt (blk->end, hole->end))
1024 hole_index = scoreboard_hole_index (sb, hole);
1025 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
1028 /* Pool might've moved */
1029 hole = scoreboard_get_hole (sb, hole_index);
1030 hole->end = blk->start;
1032 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
1034 else if (seq_lt (blk->start, hole->end))
1036 hole->end = blk->start;
1038 hole = scoreboard_next_hole (sb, hole);
1042 if (pool_elts (sb->holes) == 1)
1044 hole = scoreboard_first_hole (sb);
1045 if (hole->start == ack + sb->snd_una_adv
1046 && hole->end == tc->snd_una_max)
1047 scoreboard_remove_hole (sb, hole);
1050 scoreboard_update_bytes (tc, sb);
1051 sb->last_sacked_bytes = sb->sacked_bytes
1052 - (old_sacked_bytes - sb->last_bytes_delivered);
1053 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
1054 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
1055 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
1056 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
1057 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1058 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1059 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
1060 TCP_EVT_DBG (TCP_EVT_CC_SCOREBOARD, tc);
1064 * Try to update snd_wnd based on feedback received from peer.
1066 * If successful, and new window is 'effectively' 0, activate persist
1070 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1072 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1073 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1074 if (seq_lt (tc->snd_wl1, seq)
1075 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1077 tc->snd_wnd = snd_wnd;
1080 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
1082 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
1084 /* Set persist timer if not set and we just got 0 wnd */
1085 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1086 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1087 tcp_persist_timer_set (tc);
1091 tcp_persist_timer_reset (tc);
1092 if (PREDICT_FALSE (!tcp_in_recovery (tc) && tc->rto_boff > 0))
1095 tcp_update_rto (tc);
1102 * Init loss recovery/fast recovery.
1104 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1105 * updated in @ref tcp_cc_handle_event after fast retransmit
1108 tcp_cc_init_congestion (tcp_connection_t * tc)
1110 tcp_fastrecovery_on (tc);
1111 tc->snd_congestion = tc->snd_una_max;
1112 tc->cwnd_acc_bytes = 0;
1113 tc->snd_rxt_bytes = 0;
1114 tc->prev_ssthresh = tc->ssthresh;
1115 tc->prev_cwnd = tc->cwnd;
1116 tc->cc_algo->congestion (tc);
1117 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
1121 tcp_cc_recovery_exit (tcp_connection_t * tc)
1124 tcp_update_rto (tc);
1126 tc->snd_nxt = tc->snd_una_max;
1128 tcp_recovery_off (tc);
1129 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1133 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
1135 tc->cc_algo->recovered (tc);
1136 tc->snd_rxt_bytes = 0;
1137 tc->rcv_dupacks = 0;
1138 tc->snd_nxt = tc->snd_una_max;
1139 tc->snd_rxt_bytes = 0;
1142 tcp_fastrecovery_off (tc);
1143 tcp_fastrecovery_first_off (tc);
1145 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1149 tcp_cc_congestion_undo (tcp_connection_t * tc)
1151 tc->cwnd = tc->prev_cwnd;
1152 tc->ssthresh = tc->prev_ssthresh;
1153 tc->snd_nxt = tc->snd_una_max;
1154 tc->rcv_dupacks = 0;
1155 if (tcp_in_recovery (tc))
1156 tcp_cc_recovery_exit (tc);
1157 else if (tcp_in_fastrecovery (tc))
1158 tcp_cc_fastrecovery_exit (tc);
1159 ASSERT (tc->rto_boff == 0);
1160 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
1164 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1166 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1168 && tcp_opts_tstamp (&tc->rcv_opts)
1169 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1173 tcp_cc_is_spurious_fast_rxt (tcp_connection_t * tc)
1175 return (tcp_in_fastrecovery (tc)
1176 && tc->cwnd > tc->ssthresh + 3 * tc->snd_mss);
1180 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1182 return (tcp_cc_is_spurious_timeout_rxt (tc)
1183 || tcp_cc_is_spurious_fast_rxt (tc));
1187 tcp_cc_recover (tcp_connection_t * tc)
1189 ASSERT (tcp_in_cong_recovery (tc));
1190 if (tcp_cc_is_spurious_retransmit (tc))
1192 tcp_cc_congestion_undo (tc);
1196 if (tcp_in_recovery (tc))
1197 tcp_cc_recovery_exit (tc);
1198 else if (tcp_in_fastrecovery (tc))
1199 tcp_cc_fastrecovery_exit (tc);
1201 ASSERT (tc->rto_boff == 0);
1202 ASSERT (!tcp_in_cong_recovery (tc));
1203 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1208 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
1210 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1212 /* Congestion avoidance */
1213 tcp_cc_rcv_ack (tc);
1215 /* If a cumulative ack, make sure dupacks is 0 */
1216 tc->rcv_dupacks = 0;
1218 /* When dupacks hits the threshold we only enter fast retransmit if
1219 * cumulative ack covers more than snd_congestion. Should snd_una
1220 * wrap this test may fail under otherwise valid circumstances.
1221 * Therefore, proactively update snd_congestion when wrap detected. */
1223 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1224 && seq_gt (tc->snd_congestion, tc->snd_una)))
1225 tc->snd_congestion = tc->snd_una - 1;
1229 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1231 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1235 tcp_should_fastrecover (tcp_connection_t * tc)
1237 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1238 || tcp_should_fastrecover_sack (tc));
1242 tcp_program_fastretransmit (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1244 if (!(tc->flags & TCP_CONN_FRXT_PENDING))
1246 vec_add1 (wrk->pending_fast_rxt, tc->c_c_index);
1247 tc->flags |= TCP_CONN_FRXT_PENDING;
1252 tcp_do_fastretransmits (tcp_worker_ctx_t * wrk)
1254 u32 *ongoing_fast_rxt, burst_bytes, sent_bytes, thread_index;
1255 u32 max_burst_size, burst_size, n_segs = 0, n_segs_now;
1256 tcp_connection_t *tc;
1260 if (vec_len (wrk->pending_fast_rxt) == 0
1261 && vec_len (wrk->postponed_fast_rxt) == 0)
1264 thread_index = wrk->vm->thread_index;
1265 last_cpu_time = wrk->vm->clib_time.last_cpu_time;
1266 ongoing_fast_rxt = wrk->ongoing_fast_rxt;
1267 vec_append (ongoing_fast_rxt, wrk->postponed_fast_rxt);
1268 vec_append (ongoing_fast_rxt, wrk->pending_fast_rxt);
1270 _vec_len (wrk->postponed_fast_rxt) = 0;
1271 _vec_len (wrk->pending_fast_rxt) = 0;
1273 max_burst_size = VLIB_FRAME_SIZE / vec_len (ongoing_fast_rxt);
1274 max_burst_size = clib_max (max_burst_size, 1);
1276 for (i = 0; i < vec_len (ongoing_fast_rxt); i++)
1278 if (n_segs >= VLIB_FRAME_SIZE)
1280 vec_add1 (wrk->postponed_fast_rxt, ongoing_fast_rxt[i]);
1284 tc = tcp_connection_get (ongoing_fast_rxt[i], thread_index);
1285 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1287 if (!tcp_in_fastrecovery (tc))
1290 burst_size = clib_min (max_burst_size, VLIB_FRAME_SIZE - n_segs);
1291 burst_bytes = transport_connection_tx_pacer_burst (&tc->connection,
1293 burst_size = clib_min (burst_size, burst_bytes / tc->snd_mss);
1296 tcp_program_fastretransmit (wrk, tc);
1300 n_segs_now = tcp_fast_retransmit (wrk, tc, burst_size);
1301 sent_bytes = clib_min (n_segs_now * tc->snd_mss, burst_bytes);
1302 transport_connection_tx_pacer_update_bytes (&tc->connection,
1304 n_segs += n_segs_now;
1306 _vec_len (ongoing_fast_rxt) = 0;
1307 wrk->ongoing_fast_rxt = ongoing_fast_rxt;
1311 * One function to rule them all ... and in the darkness bind them
1314 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1318 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1320 if (tc->bytes_acked)
1322 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1326 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1327 * it account for the bytes that left the network.
1329 else if (is_dack && !tcp_in_recovery (tc))
1331 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1332 ASSERT (tc->snd_una != tc->snd_una_max
1333 || tc->sack_sb.last_sacked_bytes);
1337 /* Pure duplicate ack. If some data got acked, it's handled lower */
1338 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1340 ASSERT (tcp_in_fastrecovery (tc));
1341 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1344 else if (tcp_should_fastrecover (tc))
1348 ASSERT (!tcp_in_fastrecovery (tc));
1350 /* Heuristic to catch potential late dupacks
1351 * after fast retransmit exits */
1352 if (is_dack && tc->snd_una == tc->snd_congestion
1353 && timestamp_leq (tc->rcv_opts.tsecr, tc->tsecr_last_ack))
1355 tc->rcv_dupacks = 0;
1359 tcp_cc_init_congestion (tc);
1360 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1362 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1364 tc->cwnd = tc->ssthresh;
1365 scoreboard_init_high_rxt (&tc->sack_sb, tc->snd_una);
1369 /* Post retransmit update cwnd to ssthresh and account for the
1370 * three segments that have left the network and should've been
1371 * buffered at the receiver XXX */
1372 tc->cwnd = tc->ssthresh + 3 * tc->snd_mss;
1375 /* Constrain rate until we get a partial ack */
1376 pacer_wnd = clib_max (0.1 * tc->cwnd, 2 * tc->snd_mss);
1377 tcp_connection_tx_pacer_reset (tc, pacer_wnd,
1378 0 /* start bucket */ );
1379 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index),
1383 else if (!tc->bytes_acked
1384 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1386 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1392 /* Don't allow entry in fast recovery if still in recovery, for now */
1393 else if (0 && is_dack && tcp_in_recovery (tc))
1395 /* If of of the two conditions lower hold, reset dupacks because
1396 * we're probably after timeout (RFC6582 heuristics).
1397 * If Cumulative ack does not cover more than congestion threshold,
1399 * 1) The following doesn't hold: The congestion window is greater
1400 * than SMSS bytes and the difference between highest_ack
1401 * and prev_highest_ack is at most 4*SMSS bytes
1402 * 2) Echoed timestamp in the last non-dup ack does not equal the
1405 if (seq_leq (tc->snd_una, tc->snd_congestion)
1406 && ((!(tc->cwnd > tc->snd_mss
1407 && tc->bytes_acked <= 4 * tc->snd_mss))
1408 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1410 tc->rcv_dupacks = 0;
1415 if (!tc->bytes_acked)
1419 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1422 * Legitimate ACK. 1) See if we can exit recovery
1425 /* Update the pacing rate. For the first partial ack we move from
1426 * the artificially constrained rate to the one after congestion */
1427 tcp_connection_tx_pacer_update (tc);
1429 if (seq_geq (tc->snd_una, tc->snd_congestion))
1431 tcp_retransmit_timer_update (tc);
1433 /* If spurious return, we've already updated everything */
1434 if (tcp_cc_recover (tc))
1436 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1440 tc->snd_nxt = tc->snd_una_max;
1442 /* Treat as congestion avoidance ack */
1443 tcp_cc_rcv_ack (tc);
1448 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1451 /* XXX limit this only to first partial ack? */
1452 tcp_retransmit_timer_update (tc);
1454 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1455 * reset dupacks to 0. Also needed if in congestion recovery */
1456 tc->rcv_dupacks = 0;
1458 /* Post RTO timeout don't try anything fancy */
1459 if (tcp_in_recovery (tc))
1461 tcp_cc_rcv_ack (tc);
1462 transport_add_tx_event (&tc->connection);
1466 /* Remove retransmitted bytes that have been delivered */
1467 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1469 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1470 >= tc->sack_sb.last_bytes_delivered
1471 || (tc->flags & TCP_CONN_FINSNT));
1473 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1474 * remove sacked bytes delivered */
1475 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1477 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1478 - tc->sack_sb.last_bytes_delivered;
1479 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1480 tc->snd_rxt_bytes -= rxt_delivered;
1484 /* Apparently all retransmitted holes have been acked */
1485 tc->snd_rxt_bytes = 0;
1486 tc->sack_sb.high_rxt = tc->snd_una;
1491 tcp_fastrecovery_first_on (tc);
1492 /* Reuse last bytes delivered to track total bytes acked */
1493 tc->sack_sb.last_bytes_delivered += tc->bytes_acked;
1494 if (tc->snd_rxt_bytes > tc->bytes_acked)
1495 tc->snd_rxt_bytes -= tc->bytes_acked;
1497 tc->snd_rxt_bytes = 0;
1500 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1503 * Since this was a partial ack, try to retransmit some more data
1505 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1509 * Process incoming ACK
1512 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1513 tcp_header_t * th, u32 * error)
1515 u32 prev_snd_wnd, prev_snd_una;
1518 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1520 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1521 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1523 /* When we entered recovery, we reset snd_nxt to snd_una. Seems peer
1524 * still has the data so accept the ack */
1525 if (tcp_in_recovery (tc)
1526 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_congestion))
1528 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1529 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
1530 tc->snd_una_max = tc->snd_nxt;
1534 /* If we have outstanding data and this is within the window, accept it,
1535 * probably retransmit has timed out. Otherwise ACK segment and then
1537 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1539 tcp_program_ack (wrk, tc);
1540 *error = TCP_ERROR_ACK_FUTURE;
1541 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1542 vnet_buffer (b)->tcp.ack_number);
1546 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1547 vnet_buffer (b)->tcp.ack_number);
1549 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1552 /* If old ACK, probably it's an old dupack */
1553 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1555 *error = TCP_ERROR_ACK_OLD;
1556 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1557 vnet_buffer (b)->tcp.ack_number);
1558 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1559 tcp_cc_handle_event (tc, 1);
1560 /* Don't drop yet */
1565 * Looks okay, process feedback
1568 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1569 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1571 prev_snd_wnd = tc->snd_wnd;
1572 prev_snd_una = tc->snd_una;
1573 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1574 vnet_buffer (b)->tcp.ack_number,
1575 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1576 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1577 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1578 tcp_validate_txf_size (tc, tc->bytes_acked);
1580 if (tc->bytes_acked)
1582 tcp_program_dequeue (wrk, tc);
1583 tcp_update_rtt (tc, vnet_buffer (b)->tcp.ack_number);
1586 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1589 * Check if we have congestion event
1592 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1594 tcp_cc_handle_event (tc, is_dack);
1595 if (!tcp_in_cong_recovery (tc))
1597 *error = TCP_ERROR_ACK_DUP;
1598 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1604 * Update congestion control (slow start/congestion avoidance)
1606 tcp_cc_update (tc, b);
1607 *error = TCP_ERROR_ACK_OK;
1612 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1614 if (!tcp_disconnect_pending (tc))
1616 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1617 tcp_disconnect_pending_on (tc);
1622 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1624 u32 thread_index, *pending_disconnects;
1625 tcp_connection_t *tc;
1628 if (!vec_len (wrk->pending_disconnects))
1631 thread_index = wrk->vm->thread_index;
1632 pending_disconnects = wrk->pending_disconnects;
1633 for (i = 0; i < vec_len (pending_disconnects); i++)
1635 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1636 tcp_disconnect_pending_off (tc);
1637 stream_session_disconnect_notify (&tc->connection);
1639 _vec_len (wrk->pending_disconnects) = 0;
1643 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1646 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1647 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1648 /* Account for the FIN if nothing else was received */
1649 if (vnet_buffer (b)->tcp.data_len == 0)
1651 tcp_program_ack (wrk, tc);
1652 tc->state = TCP_STATE_CLOSE_WAIT;
1653 tcp_program_disconnect (wrk, tc);
1654 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1655 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc);
1656 *error = TCP_ERROR_FIN_RCVD;
1660 tcp_sack_vector_is_sane (sack_block_t * sacks)
1663 for (i = 1; i < vec_len (sacks); i++)
1665 if (sacks[i - 1].end == sacks[i].start)
1672 * Build SACK list as per RFC2018.
1674 * Makes sure the first block contains the segment that generated the current
1675 * ACK and the following ones are the ones most recently reported in SACK
1678 * @param tc TCP connection for which the SACK list is updated
1679 * @param start Start sequence number of the newest SACK block
1680 * @param end End sequence of the newest SACK block
1683 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1685 sack_block_t *new_list = 0, *block = 0;
1688 /* If the first segment is ooo add it to the list. Last write might've moved
1689 * rcv_nxt over the first segment. */
1690 if (seq_lt (tc->rcv_nxt, start))
1692 vec_add2 (new_list, block, 1);
1693 block->start = start;
1697 /* Find the blocks still worth keeping. */
1698 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1700 /* Discard if rcv_nxt advanced beyond current block */
1701 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1704 /* Merge or drop if segment overlapped by the new segment */
1705 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1706 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1708 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1709 new_list[0].start = tc->snd_sacks[i].start;
1710 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1711 new_list[0].end = tc->snd_sacks[i].end;
1715 /* Save to new SACK list if we have space. */
1716 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1718 vec_add1 (new_list, tc->snd_sacks[i]);
1722 clib_warning ("sack discarded");
1726 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1728 /* Replace old vector with new one */
1729 vec_free (tc->snd_sacks);
1730 tc->snd_sacks = new_list;
1732 /* Segments should not 'touch' */
1733 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1737 tcp_sack_list_bytes (tcp_connection_t * tc)
1740 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1741 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1745 /** Enqueue data for delivery to application */
1747 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1750 int written, error = TCP_ERROR_ENQUEUED;
1752 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1754 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1755 1 /* queue event */ , 1);
1757 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1759 /* Update rcv_nxt */
1760 if (PREDICT_TRUE (written == data_len))
1762 tc->rcv_nxt += written;
1764 /* If more data written than expected, account for out-of-order bytes. */
1765 else if (written > data_len)
1767 tc->rcv_nxt += written;
1768 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1770 else if (written > 0)
1772 /* We've written something but FIFO is probably full now */
1773 tc->rcv_nxt += written;
1774 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1778 return TCP_ERROR_FIFO_FULL;
1781 /* Update SACK list if need be */
1782 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1784 /* Remove SACK blocks that have been delivered */
1785 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1791 /** Enqueue out-of-order data */
1793 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1796 stream_session_t *s0;
1799 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1802 /* Enqueue out-of-order data with relative offset */
1803 rv = session_enqueue_stream_connection (&tc->connection, b,
1804 vnet_buffer (b)->tcp.seq_number -
1805 tc->rcv_nxt, 0 /* queue event */ ,
1808 /* Nothing written */
1811 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1812 return TCP_ERROR_FIFO_FULL;
1815 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1817 /* Update SACK list if in use */
1818 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1820 ooo_segment_t *newest;
1823 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1825 /* Get the newest segment from the fifo */
1826 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1829 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1830 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1831 start = tc->rcv_nxt + offset;
1832 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1833 tcp_update_sack_list (tc, start, end);
1834 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1835 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1839 return TCP_ERROR_ENQUEUED_OOO;
1843 * Check if ACK could be delayed. If ack can be delayed, it should return
1844 * true for a full frame. If we're always acking return 0.
1847 tcp_can_delack (tcp_connection_t * tc)
1849 /* Send ack if ... */
1851 /* just sent a rcv wnd 0 */
1852 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1853 /* constrained to send ack */
1854 || (tc->flags & TCP_CONN_SNDACK) != 0
1855 /* we're almost out of tx wnd */
1856 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1863 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1865 u32 discard, first = b->current_length;
1866 vlib_main_t *vm = vlib_get_main ();
1868 /* Handle multi-buffer segments */
1869 if (n_bytes_to_drop > b->current_length)
1871 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1875 discard = clib_min (n_bytes_to_drop, b->current_length);
1876 vlib_buffer_advance (b, discard);
1877 b = vlib_get_buffer (vm, b->next_buffer);
1878 n_bytes_to_drop -= discard;
1880 while (n_bytes_to_drop);
1881 if (n_bytes_to_drop > first)
1882 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1885 vlib_buffer_advance (b, n_bytes_to_drop);
1886 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1891 * Receive buffer for connection and handle acks
1893 * It handles both in order or out-of-order data.
1896 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1899 u32 error, n_bytes_to_drop, n_data_bytes;
1901 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1902 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1903 ASSERT (n_data_bytes);
1905 /* Handle out-of-order data */
1906 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1908 /* Old sequence numbers allowed through because they overlapped
1910 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1912 /* Completely in the past (possible retransmit). Ack
1913 * retransmissions since we may not have any data to send */
1914 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1916 tcp_program_ack (wrk, tc);
1917 error = TCP_ERROR_SEGMENT_OLD;
1921 /* Chop off the bytes in the past and see if what is left
1922 * can be enqueued in order */
1923 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1924 n_data_bytes -= n_bytes_to_drop;
1925 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1926 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1928 error = TCP_ERROR_SEGMENT_OLD;
1934 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1935 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1936 tcp_program_dupack (wrk, tc);
1937 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1943 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1944 * segments can be enqueued after fifo tail offset changes. */
1945 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1946 if (tcp_can_delack (tc))
1948 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1949 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1953 tcp_program_ack (wrk, tc);
1961 tcp_header_t tcp_header;
1962 tcp_connection_t tcp_connection;
1966 format_tcp_rx_trace (u8 * s, va_list * args)
1968 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1969 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1970 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1971 u32 indent = format_get_indent (s);
1973 s = format (s, "%U\n%U%U",
1974 format_tcp_header, &t->tcp_header, 128,
1975 format_white_space, indent,
1976 format_tcp_connection, &t->tcp_connection, 1);
1982 format_tcp_rx_trace_short (u8 * s, va_list * args)
1984 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1985 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1986 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1988 s = format (s, "%d -> %d (%U)",
1989 clib_net_to_host_u16 (t->tcp_header.dst_port),
1990 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
1991 t->tcp_connection.state);
1997 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1998 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
2002 clib_memcpy_fast (&t0->tcp_connection, tc0,
2003 sizeof (t0->tcp_connection));
2007 th0 = tcp_buffer_hdr (b0);
2009 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2013 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2014 vlib_frame_t * frame, u8 is_ip4)
2018 n_left = frame->n_vectors;
2019 from = vlib_frame_vector_args (frame);
2023 tcp_connection_t *tc0;
2030 b0 = vlib_get_buffer (vm, bi0);
2032 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2034 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2035 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2037 th0 = tcp_buffer_hdr (b0);
2038 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2047 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2048 u8 is_ip4, u32 evt, u32 val)
2051 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2053 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2056 #define tcp_maybe_inc_counter(node_id, err, count) \
2058 if (next0 != tcp_next_drop (is_ip4)) \
2059 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2060 tcp6_##node_id##_node.index, is_ip4, err, \
2063 #define tcp_inc_counter(node_id, err, count) \
2064 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2065 tcp6_##node_id##_node.index, is_ip4, \
2067 #define tcp_maybe_inc_err_counter(cnts, err) \
2069 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2071 #define tcp_inc_err_counter(cnts, err, val) \
2075 #define tcp_store_err_counters(node_id, cnts) \
2078 for (i = 0; i < TCP_N_ERROR; i++) \
2080 tcp_inc_counter(node_id, i, cnts[i]); \
2085 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2086 vlib_frame_t * frame, int is_ip4)
2088 u32 thread_index = vm->thread_index, errors = 0;
2089 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2090 u32 n_left_from, *from, *first_buffer;
2091 u16 err_counters[TCP_N_ERROR] = { 0 };
2094 if (node->flags & VLIB_NODE_FLAG_TRACE)
2095 tcp_established_trace_frame (vm, node, frame, is_ip4);
2097 first_buffer = from = vlib_frame_vector_args (frame);
2098 n_left_from = frame->n_vectors;
2100 while (n_left_from > 0)
2102 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2104 tcp_header_t *th0 = 0;
2105 tcp_connection_t *tc0;
2107 if (n_left_from > 1)
2110 pb = vlib_get_buffer (vm, from[1]);
2111 vlib_prefetch_buffer_header (pb, LOAD);
2112 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2119 b0 = vlib_get_buffer (vm, bi0);
2120 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2123 if (PREDICT_FALSE (tc0 == 0))
2125 error0 = TCP_ERROR_INVALID_CONNECTION;
2129 th0 = tcp_buffer_hdr (b0);
2130 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
2131 * dangling reference. */
2132 is_fin = tcp_is_fin (th0);
2134 /* SYNs, FINs and data consume sequence numbers */
2135 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2136 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
2138 /* TODO header prediction fast path */
2140 /* 1-4: check SEQ, RST, SYN */
2141 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2143 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2147 /* 5: check the ACK field */
2148 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2151 /* 6: check the URG bit TODO */
2153 /* 7: process the segment text */
2154 if (vnet_buffer (b0)->tcp.data_len)
2155 error0 = tcp_segment_rcv (wrk, tc0, b0);
2157 /* 8: check the FIN bit */
2158 if (PREDICT_FALSE (is_fin))
2159 tcp_rcv_fin (wrk, tc0, b0, &error0);
2162 tcp_inc_err_counter (err_counters, error0, 1);
2165 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2167 err_counters[TCP_ERROR_EVENT_FIFO_FULL] = errors;
2168 tcp_store_err_counters (established, err_counters);
2169 tcp_handle_postponed_dequeues (wrk);
2170 tcp_handle_disconnects (wrk);
2171 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2173 return frame->n_vectors;
2177 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2178 vlib_frame_t * from_frame)
2180 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2184 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2185 vlib_frame_t * from_frame)
2187 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2191 VLIB_REGISTER_NODE (tcp4_established_node) =
2193 .function = tcp4_established,
2194 .name = "tcp4-established",
2195 /* Takes a vector of packets. */
2196 .vector_size = sizeof (u32),
2197 .n_errors = TCP_N_ERROR,
2198 .error_strings = tcp_error_strings,
2199 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2202 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2203 foreach_tcp_state_next
2206 .format_trace = format_tcp_rx_trace_short,
2210 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
2213 VLIB_REGISTER_NODE (tcp6_established_node) =
2215 .function = tcp6_established,
2216 .name = "tcp6-established",
2217 /* Takes a vector of packets. */
2218 .vector_size = sizeof (u32),
2219 .n_errors = TCP_N_ERROR,
2220 .error_strings = tcp_error_strings,
2221 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2224 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2225 foreach_tcp_state_next
2228 .format_trace = format_tcp_rx_trace_short,
2233 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
2235 vlib_node_registration_t tcp4_syn_sent_node;
2236 vlib_node_registration_t tcp6_syn_sent_node;
2239 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2241 transport_connection_t *tmp = 0;
2248 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2251 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2252 && (tc->state == TCP_STATE_LISTEN
2253 || tc->c_rmt_port == hdr->src_port));
2257 handle = session_lookup_half_open_handle (&tc->connection);
2258 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2259 tc->c_proto, tc->c_is_ip4);
2263 if (tmp->lcl_port == hdr->dst_port
2264 && tmp->rmt_port == hdr->src_port)
2266 TCP_DBG ("half-open is valid!");
2274 * Lookup transport connection
2276 static tcp_connection_t *
2277 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2281 transport_connection_t *tconn;
2282 tcp_connection_t *tc;
2287 ip4 = vlib_buffer_get_current (b);
2288 tcp = ip4_next_header (ip4);
2289 tconn = session_lookup_connection_wt4 (fib_index,
2294 TRANSPORT_PROTO_TCP,
2295 thread_index, &is_filtered);
2296 tc = tcp_get_connection_from_transport (tconn);
2297 ASSERT (tcp_lookup_is_valid (tc, tcp));
2302 ip6 = vlib_buffer_get_current (b);
2303 tcp = ip6_next_header (ip6);
2304 tconn = session_lookup_connection_wt6 (fib_index,
2309 TRANSPORT_PROTO_TCP,
2310 thread_index, &is_filtered);
2311 tc = tcp_get_connection_from_transport (tconn);
2312 ASSERT (tcp_lookup_is_valid (tc, tcp));
2318 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2319 vlib_frame_t * from_frame, int is_ip4)
2321 tcp_main_t *tm = vnet_get_tcp_main ();
2322 u32 n_left_from, *from, *first_buffer, errors = 0;
2323 u32 my_thread_index = vm->thread_index;
2324 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2326 from = first_buffer = vlib_frame_vector_args (from_frame);
2327 n_left_from = from_frame->n_vectors;
2329 while (n_left_from > 0)
2331 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2332 tcp_connection_t *tc0, *new_tc0;
2333 tcp_header_t *tcp0 = 0;
2341 b0 = vlib_get_buffer (vm, bi0);
2343 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2344 if (PREDICT_FALSE (tc0 == 0))
2346 error0 = TCP_ERROR_INVALID_CONNECTION;
2350 /* Half-open completed recently but the connection was't removed
2351 * yet by the owning thread */
2352 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2354 /* Make sure the connection actually exists */
2355 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2356 my_thread_index, is_ip4));
2360 ack0 = vnet_buffer (b0)->tcp.ack_number;
2361 seq0 = vnet_buffer (b0)->tcp.seq_number;
2362 tcp0 = tcp_buffer_hdr (b0);
2364 /* Crude check to see if the connection handle does not match
2365 * the packet. Probably connection just switched to established */
2366 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2367 || tcp0->src_port != tc0->c_rmt_port))
2369 error0 = TCP_ERROR_INVALID_CONNECTION;
2373 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2374 && !tcp_syn (tcp0)))
2376 error0 = TCP_ERROR_SEGMENT_INVALID;
2380 /* SYNs, FINs and data consume sequence numbers */
2381 vnet_buffer (b0)->tcp.seq_end =
2382 seq0 + tcp_is_syn (tcp0) + tcp_is_fin (tcp0) +
2383 vnet_buffer (b0)->tcp.data_len;
2386 * 1. check the ACK bit
2390 * If the ACK bit is set
2391 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2392 * the RST bit is set, if so drop the segment and return)
2393 * <SEQ=SEG.ACK><CTL=RST>
2394 * and discard the segment. Return.
2395 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2399 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2401 if (!tcp_rst (tcp0))
2402 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2403 error0 = TCP_ERROR_RCV_WND;
2407 /* Make sure ACK is valid */
2408 if (seq_gt (tc0->snd_una, ack0))
2410 error0 = TCP_ERROR_ACK_INVALID;
2416 * 2. check the RST bit
2421 /* If ACK is acceptable, signal client that peer is not
2422 * willing to accept connection and drop connection*/
2424 tcp_connection_reset (tc0);
2425 error0 = TCP_ERROR_RST_RCVD;
2430 * 3. check the security and precedence (skipped)
2434 * 4. check the SYN bit
2437 /* No SYN flag. Drop. */
2438 if (!tcp_syn (tcp0))
2440 clib_warning ("not synack");
2441 error0 = TCP_ERROR_SEGMENT_INVALID;
2446 if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1))
2448 clib_warning ("options parse fail");
2449 error0 = TCP_ERROR_OPTIONS;
2453 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2454 * current thread pool. */
2455 pool_get (tm->connections[my_thread_index], new_tc0);
2456 clib_memcpy_fast (new_tc0, tc0, sizeof (*new_tc0));
2457 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2458 new_tc0->c_thread_index = my_thread_index;
2459 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2460 new_tc0->irs = seq0;
2461 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
2462 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2463 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2465 /* If this is not the owning thread, wait for syn retransmit to
2466 * expire and cleanup then */
2467 if (tcp_half_open_connection_cleanup (tc0))
2468 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2470 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2472 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2473 new_tc0->tsval_recent_age = tcp_time_now ();
2476 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2477 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2479 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2480 << new_tc0->snd_wscale;
2481 new_tc0->snd_wl1 = seq0;
2482 new_tc0->snd_wl2 = ack0;
2484 tcp_connection_init_vars (new_tc0);
2486 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2487 if (PREDICT_TRUE (tcp_ack (tcp0)))
2489 /* Our SYN is ACKed: we have iss < ack = snd_una */
2491 /* TODO Dequeue acknowledged segments if we support Fast Open */
2492 new_tc0->snd_una = ack0;
2493 new_tc0->state = TCP_STATE_ESTABLISHED;
2495 /* Make sure las is initialized for the wnd computation */
2496 new_tc0->rcv_las = new_tc0->rcv_nxt;
2498 /* Notify app that we have connection. If session layer can't
2499 * allocate session send reset */
2500 if (session_stream_connect_notify (&new_tc0->connection, 0))
2502 clib_warning ("connect notify fail");
2503 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2504 tcp_connection_cleanup (new_tc0);
2508 new_tc0->tx_fifo_size =
2509 transport_tx_fifo_size (&new_tc0->connection);
2510 /* Update rtt with the syn-ack sample */
2511 tcp_estimate_initial_rtt (new_tc0);
2512 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2513 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2515 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2518 new_tc0->state = TCP_STATE_SYN_RCVD;
2520 /* Notify app that we have connection */
2521 if (session_stream_connect_notify (&new_tc0->connection, 0))
2523 tcp_connection_cleanup (new_tc0);
2524 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2525 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2529 new_tc0->tx_fifo_size =
2530 transport_tx_fifo_size (&new_tc0->connection);
2531 new_tc0->rtt_ts = 0;
2532 tcp_init_snd_vars (new_tc0);
2533 tcp_send_synack (new_tc0);
2534 error0 = TCP_ERROR_SYNS_RCVD;
2538 /* Read data, if any */
2539 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2541 clib_warning ("rcvd data in syn-sent");
2542 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2543 if (error0 == TCP_ERROR_ACK_OK)
2544 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2548 tcp_program_ack (wrk, new_tc0);
2553 tcp_inc_counter (syn_sent, error0, 1);
2554 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2556 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2557 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2558 clib_memcpy_fast (&t0->tcp_connection, tc0,
2559 sizeof (t0->tcp_connection));
2563 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2565 tcp_inc_counter (syn_sent, TCP_ERROR_EVENT_FIFO_FULL, errors);
2566 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2568 return from_frame->n_vectors;
2572 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2573 vlib_frame_t * from_frame)
2575 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2579 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2580 vlib_frame_t * from_frame)
2582 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2586 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2588 .function = tcp4_syn_sent,
2589 .name = "tcp4-syn-sent",
2590 /* Takes a vector of packets. */
2591 .vector_size = sizeof (u32),
2592 .n_errors = TCP_N_ERROR,
2593 .error_strings = tcp_error_strings,
2594 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2597 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2598 foreach_tcp_state_next
2601 .format_trace = format_tcp_rx_trace_short,
2605 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2608 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2610 .function = tcp6_syn_sent_rcv,
2611 .name = "tcp6-syn-sent",
2612 /* Takes a vector of packets. */
2613 .vector_size = sizeof (u32),
2614 .n_errors = TCP_N_ERROR,
2615 .error_strings = tcp_error_strings,
2616 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2619 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2620 foreach_tcp_state_next
2623 .format_trace = format_tcp_rx_trace_short,
2627 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2629 vlib_node_registration_t tcp4_rcv_process_node;
2630 vlib_node_registration_t tcp6_rcv_process_node;
2633 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2634 * as per RFC793 p. 64
2637 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2638 vlib_frame_t * from_frame, int is_ip4)
2640 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2641 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2642 u32 n_left_from, *from;
2644 from = first_buffer = vlib_frame_vector_args (from_frame);
2645 n_left_from = from_frame->n_vectors;
2647 while (n_left_from > 0)
2649 u32 bi0, error0 = TCP_ERROR_NONE;
2650 tcp_header_t *tcp0 = 0;
2651 tcp_connection_t *tc0;
2659 b0 = vlib_get_buffer (vm, bi0);
2660 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2662 if (PREDICT_FALSE (tc0 == 0))
2664 error0 = TCP_ERROR_INVALID_CONNECTION;
2668 tcp0 = tcp_buffer_hdr (b0);
2669 is_fin0 = tcp_is_fin (tcp0);
2671 /* SYNs, FINs and data consume sequence numbers */
2672 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2673 + tcp_is_syn (tcp0) + is_fin0 + vnet_buffer (b0)->tcp.data_len;
2677 tcp_connection_t *tmp;
2678 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2680 if (tmp->state != tc0->state)
2682 clib_warning ("state changed");
2688 * Special treatment for CLOSED
2690 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2692 error0 = TCP_ERROR_CONNECTION_CLOSED;
2697 * For all other states (except LISTEN)
2700 /* 1-4: check SEQ, RST, SYN */
2701 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2704 /* 5: check the ACK field */
2707 case TCP_STATE_SYN_RCVD:
2709 * If the segment acknowledgment is not acceptable, form a
2711 * <SEQ=SEG.ACK><CTL=RST>
2714 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2716 TCP_DBG ("connection not accepted");
2717 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2718 error0 = TCP_ERROR_ACK_INVALID;
2722 /* Update rtt and rto */
2723 tcp_estimate_initial_rtt (tc0);
2725 /* Switch state to ESTABLISHED */
2726 tc0->state = TCP_STATE_ESTABLISHED;
2727 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2729 /* Initialize session variables */
2730 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2731 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2732 << tc0->rcv_opts.wscale;
2733 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2734 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2736 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2737 tcp_retransmit_timer_reset (tc0);
2738 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2739 stream_session_accept_notify (&tc0->connection);
2740 error0 = TCP_ERROR_ACK_OK;
2742 case TCP_STATE_ESTABLISHED:
2743 /* We can get packets in established state here because they
2744 * were enqueued before state change */
2745 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2749 case TCP_STATE_FIN_WAIT_1:
2750 /* In addition to the processing for the ESTABLISHED state, if
2751 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2752 * continue processing in that state. */
2753 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2756 /* Still have to send the FIN */
2757 if (tc0->flags & TCP_CONN_FINPNDG)
2759 /* TX fifo finally drained */
2760 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2763 /* If FIN is ACKed */
2764 else if (tc0->snd_una == tc0->snd_una_max)
2766 tc0->state = TCP_STATE_FIN_WAIT_2;
2767 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2769 /* Stop all retransmit timers because we have nothing more
2770 * to send. Enable waitclose though because we're willing to
2771 * wait for peer's FIN but not indefinitely. */
2772 tcp_connection_timers_reset (tc0);
2773 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2775 /* Don't try to deq the FIN acked */
2776 if (tc0->burst_acked > 1)
2777 stream_session_dequeue_drop (&tc0->connection,
2778 tc0->burst_acked - 1);
2779 tc0->burst_acked = 0;
2782 case TCP_STATE_FIN_WAIT_2:
2783 /* In addition to the processing for the ESTABLISHED state, if
2784 * the retransmission queue is empty, the user's CLOSE can be
2785 * acknowledged ("ok") but do not delete the TCB. */
2786 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2788 tc0->burst_acked = 0;
2790 case TCP_STATE_CLOSE_WAIT:
2791 /* Do the same processing as for the ESTABLISHED state. */
2792 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2795 if (tc0->flags & TCP_CONN_FINPNDG)
2797 /* TX fifo finally drained */
2798 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2801 tcp_connection_timers_reset (tc0);
2802 tc0->state = TCP_STATE_LAST_ACK;
2803 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2807 case TCP_STATE_CLOSING:
2808 /* In addition to the processing for the ESTABLISHED state, if
2809 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2810 * otherwise ignore the segment. */
2811 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2814 tc0->state = TCP_STATE_TIME_WAIT;
2815 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2816 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2820 case TCP_STATE_LAST_ACK:
2821 /* The only thing that [should] arrive in this state is an
2822 * acknowledgment of our FIN. If our FIN is now acknowledged,
2823 * delete the TCB, enter the CLOSED state, and return. */
2825 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2827 error0 = TCP_ERROR_ACK_INVALID;
2830 error0 = TCP_ERROR_ACK_OK;
2831 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2832 /* Apparently our ACK for the peer's FIN was lost */
2833 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2839 tc0->state = TCP_STATE_CLOSED;
2840 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2842 /* Don't free the connection from the data path since
2843 * we can't ensure that we have no packets already enqueued
2844 * to output. Rely instead on the waitclose timer */
2845 tcp_connection_timers_reset (tc0);
2846 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, 1);
2851 case TCP_STATE_TIME_WAIT:
2852 /* The only thing that can arrive in this state is a
2853 * retransmission of the remote FIN. Acknowledge it, and restart
2854 * the 2 MSL timeout. */
2856 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2859 tcp_program_ack (wrk, tc0);
2860 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2868 /* 6: check the URG bit TODO */
2870 /* 7: process the segment text */
2873 case TCP_STATE_ESTABLISHED:
2874 case TCP_STATE_FIN_WAIT_1:
2875 case TCP_STATE_FIN_WAIT_2:
2876 if (vnet_buffer (b0)->tcp.data_len)
2877 error0 = tcp_segment_rcv (wrk, tc0, b0);
2881 case TCP_STATE_CLOSE_WAIT:
2882 case TCP_STATE_CLOSING:
2883 case TCP_STATE_LAST_ACK:
2884 case TCP_STATE_TIME_WAIT:
2885 /* This should not occur, since a FIN has been received from the
2886 * remote side. Ignore the segment text. */
2890 /* 8: check the FIN bit */
2896 case TCP_STATE_ESTABLISHED:
2897 case TCP_STATE_SYN_RCVD:
2898 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2899 tcp_connection_timers_reset (tc0);
2901 stream_session_disconnect_notify (&tc0->connection);
2902 tc0->state = TCP_STATE_CLOSE_WAIT;
2903 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2905 case TCP_STATE_CLOSE_WAIT:
2906 case TCP_STATE_CLOSING:
2907 case TCP_STATE_LAST_ACK:
2910 case TCP_STATE_FIN_WAIT_1:
2911 tc0->state = TCP_STATE_CLOSING;
2912 tcp_program_ack (wrk, tc0);
2913 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2914 /* Wait for ACK but not forever */
2915 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2917 case TCP_STATE_FIN_WAIT_2:
2918 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2919 tc0->state = TCP_STATE_TIME_WAIT;
2920 tcp_connection_timers_reset (tc0);
2921 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2922 tcp_program_ack (wrk, tc0);
2923 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2925 case TCP_STATE_TIME_WAIT:
2926 /* Remain in the TIME-WAIT state. Restart the time-wait
2929 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2932 error0 = TCP_ERROR_FIN_RCVD;
2933 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2937 tcp_inc_counter (rcv_process, error0, 1);
2938 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2940 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2941 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2945 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2947 tcp_inc_counter (rcv_process, TCP_ERROR_EVENT_FIFO_FULL, errors);
2948 tcp_handle_postponed_dequeues (wrk);
2949 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2951 return from_frame->n_vectors;
2955 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2956 vlib_frame_t * from_frame)
2958 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2962 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2963 vlib_frame_t * from_frame)
2965 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2969 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2971 .function = tcp4_rcv_process,
2972 .name = "tcp4-rcv-process",
2973 /* Takes a vector of packets. */
2974 .vector_size = sizeof (u32),
2975 .n_errors = TCP_N_ERROR,
2976 .error_strings = tcp_error_strings,
2977 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2980 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2981 foreach_tcp_state_next
2984 .format_trace = format_tcp_rx_trace_short,
2988 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2991 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2993 .function = tcp6_rcv_process,
2994 .name = "tcp6-rcv-process",
2995 /* Takes a vector of packets. */
2996 .vector_size = sizeof (u32),
2997 .n_errors = TCP_N_ERROR,
2998 .error_strings = tcp_error_strings,
2999 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3002 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3003 foreach_tcp_state_next
3006 .format_trace = format_tcp_rx_trace_short,
3010 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
3012 vlib_node_registration_t tcp4_listen_node;
3013 vlib_node_registration_t tcp6_listen_node;
3016 * LISTEN state processing as per RFC 793 p. 65
3019 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3020 vlib_frame_t * from_frame, int is_ip4)
3022 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3023 u32 my_thread_index = vm->thread_index;
3025 from = first_buffer = vlib_frame_vector_args (from_frame);
3026 n_left_from = from_frame->n_vectors;
3028 while (n_left_from > 0)
3033 tcp_header_t *th0 = 0;
3034 tcp_connection_t *lc0;
3037 tcp_connection_t *child0;
3038 u32 error0 = TCP_ERROR_NONE;
3044 b0 = vlib_get_buffer (vm, bi0);
3045 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3049 ip40 = vlib_buffer_get_current (b0);
3050 th0 = ip4_next_header (ip40);
3054 ip60 = vlib_buffer_get_current (b0);
3055 th0 = ip6_next_header (ip60);
3058 /* Create child session. For syn-flood protection use filter */
3060 /* 1. first check for an RST: handled in dispatch */
3061 /* if (tcp_rst (th0))
3065 /* 2. second check for an ACK: handled in dispatch */
3066 /* if (tcp_ack (th0))
3068 tcp_send_reset (b0, is_ip4);
3073 /* 3. check for a SYN (did that already) */
3075 /* Make sure connection wasn't just created */
3076 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3078 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3080 error0 = TCP_ERROR_CREATE_EXISTS;
3084 /* Create child session and send SYN-ACK */
3085 child0 = tcp_connection_new (my_thread_index);
3086 child0->c_lcl_port = th0->dst_port;
3087 child0->c_rmt_port = th0->src_port;
3088 child0->c_is_ip4 = is_ip4;
3089 child0->state = TCP_STATE_SYN_RCVD;
3090 child0->c_fib_index = lc0->c_fib_index;
3094 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3095 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3099 clib_memcpy_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3100 sizeof (ip6_address_t));
3101 clib_memcpy_fast (&child0->c_rmt_ip6, &ip60->src_address,
3102 sizeof (ip6_address_t));
3105 if (tcp_options_parse (th0, &child0->rcv_opts, 1))
3107 clib_warning ("options parse fail");
3111 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3112 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3113 child0->rcv_las = child0->rcv_nxt;
3114 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3116 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3117 * segments are used to initialize PAWS. */
3118 if (tcp_opts_tstamp (&child0->rcv_opts))
3120 child0->tsval_recent = child0->rcv_opts.tsval;
3121 child0->tsval_recent_age = tcp_time_now ();
3124 if (tcp_opts_wscale (&child0->rcv_opts))
3125 child0->snd_wscale = child0->rcv_opts.wscale;
3127 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3128 << child0->snd_wscale;
3129 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3130 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3132 tcp_connection_init_vars (child0);
3133 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
3135 if (stream_session_accept (&child0->connection, lc0->c_s_index,
3138 clib_warning ("session accept fail");
3139 tcp_connection_cleanup (child0);
3140 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3144 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3145 tcp_send_synack (child0);
3146 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
3150 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3152 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3153 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3154 clib_memcpy_fast (&t0->tcp_connection, lc0,
3155 sizeof (t0->tcp_connection));
3158 n_syns += (error0 == TCP_ERROR_NONE);
3161 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3162 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3164 return from_frame->n_vectors;
3168 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3169 vlib_frame_t * from_frame)
3171 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3175 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3176 vlib_frame_t * from_frame)
3178 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3182 VLIB_REGISTER_NODE (tcp4_listen_node) =
3184 .function = tcp4_listen,
3185 .name = "tcp4-listen",
3186 /* Takes a vector of packets. */
3187 .vector_size = sizeof (u32),
3188 .n_errors = TCP_N_ERROR,
3189 .error_strings = tcp_error_strings,
3190 .n_next_nodes = TCP_LISTEN_N_NEXT,
3193 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3194 foreach_tcp_state_next
3197 .format_trace = format_tcp_rx_trace_short,
3201 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
3204 VLIB_REGISTER_NODE (tcp6_listen_node) =
3206 .function = tcp6_listen,
3207 .name = "tcp6-listen",
3208 /* Takes a vector of packets. */
3209 .vector_size = sizeof (u32),
3210 .n_errors = TCP_N_ERROR,
3211 .error_strings = tcp_error_strings,
3212 .n_next_nodes = TCP_LISTEN_N_NEXT,
3215 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3216 foreach_tcp_state_next
3219 .format_trace = format_tcp_rx_trace_short,
3223 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
3225 vlib_node_registration_t tcp4_input_node;
3226 vlib_node_registration_t tcp6_input_node;
3228 typedef enum _tcp_input_next
3230 TCP_INPUT_NEXT_DROP,
3231 TCP_INPUT_NEXT_LISTEN,
3232 TCP_INPUT_NEXT_RCV_PROCESS,
3233 TCP_INPUT_NEXT_SYN_SENT,
3234 TCP_INPUT_NEXT_ESTABLISHED,
3235 TCP_INPUT_NEXT_RESET,
3236 TCP_INPUT_NEXT_PUNT,
3240 #define foreach_tcp4_input_next \
3241 _ (DROP, "ip4-drop") \
3242 _ (LISTEN, "tcp4-listen") \
3243 _ (RCV_PROCESS, "tcp4-rcv-process") \
3244 _ (SYN_SENT, "tcp4-syn-sent") \
3245 _ (ESTABLISHED, "tcp4-established") \
3246 _ (RESET, "tcp4-reset") \
3247 _ (PUNT, "ip4-punt")
3249 #define foreach_tcp6_input_next \
3250 _ (DROP, "ip6-drop") \
3251 _ (LISTEN, "tcp6-listen") \
3252 _ (RCV_PROCESS, "tcp6-rcv-process") \
3253 _ (SYN_SENT, "tcp6-syn-sent") \
3254 _ (ESTABLISHED, "tcp6-established") \
3255 _ (RESET, "tcp6-reset") \
3256 _ (PUNT, "ip6-punt")
3258 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3261 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3262 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3264 tcp_connection_t *tc;
3269 for (i = 0; i < n_bufs; i++)
3271 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3273 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3274 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3276 tcp = vlib_buffer_get_current (bs[i]);
3277 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3283 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3285 if (*error == TCP_ERROR_FILTERED)
3287 *next = TCP_INPUT_NEXT_DROP;
3289 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3291 *next = TCP_INPUT_NEXT_PUNT;
3292 *error = TCP_ERROR_PUNT;
3296 *next = TCP_INPUT_NEXT_RESET;
3297 *error = TCP_ERROR_NO_LISTENER;
3301 static inline tcp_connection_t *
3302 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3305 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3306 int n_advance_bytes, n_data_bytes;
3307 transport_connection_t *tc;
3313 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3314 int ip_hdr_bytes = ip4_header_bytes (ip4);
3315 if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
3317 *error = TCP_ERROR_LENGTH;
3320 tcp = ip4_next_header (ip4);
3321 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3322 n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
3323 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3325 /* Length check. Checksum computed by ipx_local no need to compute again */
3326 if (PREDICT_FALSE (n_data_bytes < 0))
3328 *error = TCP_ERROR_LENGTH;
3332 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3333 &ip4->src_address, tcp->dst_port,
3334 tcp->src_port, TRANSPORT_PROTO_TCP,
3335 thread_index, &is_filtered);
3339 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3340 if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
3342 *error = TCP_ERROR_LENGTH;
3345 tcp = ip6_next_header (ip6);
3346 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3347 n_advance_bytes = tcp_header_bytes (tcp);
3348 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3350 n_advance_bytes += sizeof (ip6[0]);
3352 if (PREDICT_FALSE (n_data_bytes < 0))
3354 *error = TCP_ERROR_LENGTH;
3358 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3359 &ip6->src_address, tcp->dst_port,
3360 tcp->src_port, TRANSPORT_PROTO_TCP,
3361 thread_index, &is_filtered);
3364 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3365 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3366 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3367 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3368 vnet_buffer (b)->tcp.flags = 0;
3370 *error = is_filtered ? TCP_ERROR_FILTERED : *error;
3372 return tcp_get_connection_from_transport (tc);
3376 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3377 vlib_buffer_t * b, u16 * next, u32 * error)
3382 tcp = tcp_buffer_hdr (b);
3383 flags = tcp->flags & filter_flags;
3384 *next = tm->dispatch_table[tc->state][flags].next;
3385 *error = tm->dispatch_table[tc->state][flags].error;
3387 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3388 || *next == TCP_INPUT_NEXT_RESET))
3390 /* Overload tcp flags to store state */
3391 tcp_state_t state = tc->state;
3392 vnet_buffer (b)->tcp.flags = tc->state;
3394 if (*error == TCP_ERROR_DISPATCH)
3395 clib_warning ("disp error state %U flags %U", format_tcp_state,
3396 state, format_tcp_flags, (int) flags);
3401 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3402 vlib_frame_t * frame, int is_ip4)
3404 u32 n_left_from, *from, thread_index = vm->thread_index;
3405 tcp_main_t *tm = vnet_get_tcp_main ();
3406 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3407 u16 nexts[VLIB_FRAME_SIZE], *next;
3409 tcp_set_time_now (tcp_get_worker (thread_index));
3411 from = vlib_frame_vector_args (frame);
3412 n_left_from = frame->n_vectors;
3413 vlib_get_buffers (vm, from, bufs, n_left_from);
3418 while (n_left_from >= 4)
3420 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3421 tcp_connection_t *tc0, *tc1;
3424 vlib_prefetch_buffer_header (b[2], STORE);
3425 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3427 vlib_prefetch_buffer_header (b[3], STORE);
3428 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3431 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3433 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3434 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4);
3436 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3438 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3439 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3441 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3442 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3444 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3445 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3449 if (PREDICT_TRUE (tc0 != 0))
3451 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3452 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3453 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3456 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3458 if (PREDICT_TRUE (tc1 != 0))
3460 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3461 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3462 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3465 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3472 while (n_left_from > 0)
3474 tcp_connection_t *tc0;
3475 u32 error0 = TCP_ERROR_NO_LISTENER;
3477 if (n_left_from > 1)
3479 vlib_prefetch_buffer_header (b[1], STORE);
3480 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3483 next[0] = TCP_INPUT_NEXT_DROP;
3484 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3485 if (PREDICT_TRUE (tc0 != 0))
3487 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3488 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3489 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3492 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3499 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3500 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3502 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3503 return frame->n_vectors;
3507 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3508 vlib_frame_t * from_frame)
3510 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3514 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3515 vlib_frame_t * from_frame)
3517 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3521 VLIB_REGISTER_NODE (tcp4_input_node) =
3523 .function = tcp4_input,
3524 .name = "tcp4-input",
3525 /* Takes a vector of packets. */
3526 .vector_size = sizeof (u32),
3527 .n_errors = TCP_N_ERROR,
3528 .error_strings = tcp_error_strings,
3529 .n_next_nodes = TCP_INPUT_N_NEXT,
3532 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3533 foreach_tcp4_input_next
3536 .format_buffer = format_tcp_header,
3537 .format_trace = format_tcp_rx_trace,
3541 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3544 VLIB_REGISTER_NODE (tcp6_input_node) =
3546 .function = tcp6_input,
3547 .name = "tcp6-input",
3548 /* Takes a vector of packets. */
3549 .vector_size = sizeof (u32),
3550 .n_errors = TCP_N_ERROR,
3551 .error_strings = tcp_error_strings,
3552 .n_next_nodes = TCP_INPUT_N_NEXT,
3555 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3556 foreach_tcp6_input_next
3559 .format_buffer = format_tcp_header,
3560 .format_trace = format_tcp_rx_trace,
3564 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3567 tcp_dispatch_table_init (tcp_main_t * tm)
3570 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3571 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3573 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3574 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3577 #define _(t,f,n,e) \
3579 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3580 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3583 /* SYNs for new connections -> tcp-listen. */
3584 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3585 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3586 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_RST_RCVD);
3587 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3589 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3590 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3591 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3592 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3594 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3595 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3597 /* SYN-ACK for a SYN */
3598 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3600 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3601 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3602 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3604 /* ACK for for established connection -> tcp-established. */
3605 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3606 /* FIN for for established connection -> tcp-established. */
3607 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3608 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3610 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3611 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3613 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3614 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3616 /* ACK or FIN-ACK to our FIN */
3617 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3618 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3620 /* FIN in reply to our FIN from the other side */
3621 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3622 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3623 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3624 /* FIN confirming that the peer (app) has closed */
3625 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3626 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3627 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3629 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3630 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3632 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3633 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3634 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3636 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3637 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3638 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3639 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3641 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3642 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3643 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3644 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3645 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3646 TCP_ERROR_CONNECTION_CLOSED);
3650 static clib_error_t *
3651 tcp_input_init (vlib_main_t * vm)
3653 clib_error_t *error = 0;
3654 tcp_main_t *tm = vnet_get_tcp_main ();
3656 if ((error = vlib_call_init_function (vm, tcp_init)))
3659 /* Initialize dispatch table. */
3660 tcp_dispatch_table_init (tm);
3665 VLIB_INIT_FUNCTION (tcp_input_init);
3668 * fd.io coding-style-patch-verification: ON
3671 * eval: (c-set-style "gnu")