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)
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;
310 TCP_EVT_DBG (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
311 vnet_buffer (b0)->tcp.seq_end);
313 /* If it just so happens that a segment updates tsval_recent for a
314 * segment over 24 days old, invalidate tsval_recent. */
315 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
316 tcp_time_now_w_thread (tc0->c_thread_index)))
318 tc0->tsval_recent = tc0->rcv_opts.tsval;
319 clib_warning ("paws failed - really old segment. REALLY?");
323 /* Drop after ack if not rst */
326 tcp_program_ack (wrk, tc0);
327 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
333 /* 1st: check sequence number */
334 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
335 vnet_buffer (b0)->tcp.seq_end))
337 *error0 = TCP_ERROR_RCV_WND;
338 /* If our window is 0 and the packet is in sequence, let it pass
339 * through for ack processing. It should be dropped later. */
340 if (!(tc0->rcv_wnd == 0
341 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number))
343 /* If not RST, send dup ack */
346 tcp_program_dupack (wrk, tc0);
347 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
353 /* 2nd: check the RST bit */
354 if (PREDICT_FALSE (tcp_rst (th0)))
356 tcp_connection_reset (tc0);
357 *error0 = TCP_ERROR_RST_RCVD;
361 /* 3rd: check security and precedence (skip) */
363 /* 4th: check the SYN bit */
364 if (PREDICT_FALSE (tcp_syn (th0)))
366 /* TODO implement RFC 5961 */
367 if (tc0->state == TCP_STATE_SYN_RCVD)
369 tcp_options_parse (th0, &tc0->rcv_opts, 1);
370 tcp_send_synack (tc0);
371 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0, 0);
375 tcp_program_ack (wrk, tc0);
376 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, tc0);
381 /* If segment in window, save timestamp */
382 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
383 vnet_buffer (b0)->tcp.seq_end);
391 tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0)
393 /* SND.UNA =< SEG.ACK =< SND.NXT */
394 return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number)
395 && seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt));
399 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
401 * Note that although the original article, srtt and rttvar are scaled
402 * to minimize round-off errors, here we don't. Instead, we rely on
403 * better precision time measurements.
405 * TODO support us rtt resolution
408 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
414 err = mrtt - tc->srtt;
416 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
417 * The increase should be bound */
418 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
419 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
420 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
424 /* First measurement. */
426 tc->rttvar = mrtt >> 1;
431 tcp_update_rto (tcp_connection_t * tc)
433 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
434 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
438 * Update RTT estimate and RTO timer
440 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
441 * timing. Middle boxes are known to fiddle with TCP options so we
442 * should give higher priority to ACK timing.
444 * This should be called only if previously sent bytes have been acked.
446 * return 1 if valid rtt 0 otherwise
449 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
453 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
454 * RTT because they're ambiguous. */
455 if (tcp_in_cong_recovery (tc) || tc->sack_sb.sacked_bytes)
457 if (tcp_in_recovery (tc))
462 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
464 f64 sample = tcp_time_now_us (tc->c_thread_index) - tc->rtt_ts;
465 tc->mrtt_us = tc->mrtt_us + (sample - tc->mrtt_us) * 0.125;
466 mrtt = clib_max ((u32) (sample * THZ), 1);
467 /* Allow measuring of a new RTT */
470 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
471 * snd_una, i.e., the left side of the send window:
472 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
473 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
475 u32 now = tcp_time_now_w_thread (tc->c_thread_index);
476 mrtt = clib_max (now - tc->rcv_opts.tsecr, 1);
479 /* Ignore dubious measurements */
480 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
483 tcp_estimate_rtt (tc, mrtt);
487 /* If we got here something must've been ACKed so make sure boff is 0,
488 * even if mrtt is not valid since we update the rto lower */
496 tcp_estimate_initial_rtt (tcp_connection_t * tc)
498 u8 thread_index = vlib_num_workers ()? 1 : 0;
503 tc->mrtt_us = tcp_time_now_us (thread_index) - tc->rtt_ts;
504 mrtt = clib_max ((u32) (tc->mrtt_us * THZ), 1);
509 mrtt = tcp_time_now_w_thread (thread_index) - tc->rcv_opts.tsecr;
510 mrtt = clib_max (mrtt, 1);
511 tc->mrtt_us = (f64) mrtt *TCP_TICK;
514 if (mrtt > 0 && mrtt < TCP_RTT_MAX)
515 tcp_estimate_rtt (tc, mrtt);
519 * Dequeue bytes for connections that have received acks in last burst
522 tcp_handle_postponed_dequeues (tcp_worker_ctx_t * wrk)
524 u32 thread_index = wrk->vm->thread_index;
525 u32 *pending_deq_acked;
526 tcp_connection_t *tc;
529 if (!vec_len (wrk->pending_deq_acked))
532 pending_deq_acked = wrk->pending_deq_acked;
533 for (i = 0; i < vec_len (pending_deq_acked); i++)
535 tc = tcp_connection_get (pending_deq_acked[i], thread_index);
536 tc->flags &= ~TCP_CONN_DEQ_PENDING;
538 if (PREDICT_FALSE (!tc->burst_acked))
541 /* Dequeue the newly ACKed bytes */
542 stream_session_dequeue_drop (&tc->connection, tc->burst_acked);
544 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
546 if (PREDICT_FALSE (tc->flags & TCP_CONN_PSH_PENDING))
548 if (seq_leq (tc->psh_seq, tc->snd_una))
549 tc->flags &= ~TCP_CONN_PSH_PENDING;
552 /* If everything has been acked, stop retransmit timer
553 * otherwise update. */
554 tcp_retransmit_timer_update (tc);
556 /* If not congested, update pacer based on our new
558 if (!tcp_in_fastrecovery (tc))
559 tcp_connection_tx_pacer_update (tc);
561 _vec_len (wrk->pending_deq_acked) = 0;
565 tcp_program_dequeue (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
567 if (!(tc->flags & TCP_CONN_DEQ_PENDING))
569 vec_add1 (wrk->pending_deq_acked, tc->c_c_index);
570 tc->flags |= TCP_CONN_DEQ_PENDING;
572 tc->burst_acked += tc->bytes_acked + tc->sack_sb.snd_una_adv;
576 * Check if duplicate ack as per RFC5681 Sec. 2
579 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
582 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
583 && seq_gt (tc->snd_una_max, tc->snd_una)
584 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
585 && (prev_snd_wnd == tc->snd_wnd));
589 * Checks if ack is a congestion control event.
592 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
593 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
595 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
596 * defined to be 'duplicate' */
597 *is_dack = tc->sack_sb.last_sacked_bytes
598 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
600 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
604 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
606 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
607 return hole - sb->holes;
611 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
613 return hole->end - hole->start;
616 sack_scoreboard_hole_t *
617 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
619 if (index != TCP_INVALID_SACK_HOLE_INDEX)
620 return pool_elt_at_index (sb->holes, index);
624 sack_scoreboard_hole_t *
625 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
627 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
628 return pool_elt_at_index (sb->holes, hole->next);
632 sack_scoreboard_hole_t *
633 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
635 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
636 return pool_elt_at_index (sb->holes, hole->prev);
640 sack_scoreboard_hole_t *
641 scoreboard_first_hole (sack_scoreboard_t * sb)
643 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
644 return pool_elt_at_index (sb->holes, sb->head);
648 sack_scoreboard_hole_t *
649 scoreboard_last_hole (sack_scoreboard_t * sb)
651 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
652 return pool_elt_at_index (sb->holes, sb->tail);
657 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
659 sack_scoreboard_hole_t *next, *prev;
661 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
663 next = pool_elt_at_index (sb->holes, hole->next);
664 next->prev = hole->prev;
668 sb->tail = hole->prev;
671 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
673 prev = pool_elt_at_index (sb->holes, hole->prev);
674 prev->next = hole->next;
678 sb->head = hole->next;
681 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
682 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
684 /* Poison the entry */
686 clib_memset (hole, 0xfe, sizeof (*hole));
688 pool_put (sb->holes, hole);
691 static sack_scoreboard_hole_t *
692 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
695 sack_scoreboard_hole_t *hole, *next, *prev;
698 pool_get (sb->holes, hole);
699 clib_memset (hole, 0, sizeof (*hole));
703 hole_index = scoreboard_hole_index (sb, hole);
705 prev = scoreboard_get_hole (sb, prev_index);
708 hole->prev = prev_index;
709 hole->next = prev->next;
711 if ((next = scoreboard_next_hole (sb, hole)))
712 next->prev = hole_index;
714 sb->tail = hole_index;
716 prev->next = hole_index;
720 sb->head = hole_index;
721 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
722 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
729 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
731 sack_scoreboard_hole_t *left, *right;
732 u32 bytes = 0, blks = 0;
735 sb->sacked_bytes = 0;
736 left = scoreboard_last_hole (sb);
740 if (seq_gt (sb->high_sacked, left->end))
742 bytes = sb->high_sacked - left->end;
746 while ((right = left)
747 && bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
748 && blks < TCP_DUPACK_THRESHOLD
749 /* left not updated if above conditions fail */
750 && (left = scoreboard_prev_hole (sb, right)))
752 bytes += right->start - left->end;
756 /* left is first lost */
761 sb->lost_bytes += scoreboard_hole_bytes (right);
763 left = scoreboard_prev_hole (sb, right);
765 bytes += right->start - left->end;
767 while ((right = left));
770 sb->sacked_bytes = bytes;
774 * Figure out the next hole to retransmit
776 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
778 sack_scoreboard_hole_t *
779 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
780 sack_scoreboard_hole_t * start,
781 u8 have_unsent, u8 * can_rescue, u8 * snd_limited)
783 sack_scoreboard_hole_t *hole = 0;
785 hole = start ? start : scoreboard_first_hole (sb);
786 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
787 hole = scoreboard_next_hole (sb, hole);
789 /* Nothing, return */
792 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
796 /* Rule (1): if higher than rxt, less than high_sacked and lost */
797 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
799 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
803 /* Rule (2): available unsent data */
806 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
809 /* Rule (3): if hole not lost */
810 else if (seq_lt (hole->start, sb->high_sacked))
813 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
815 /* Rule (4): if hole beyond high_sacked */
818 ASSERT (seq_geq (hole->start, sb->high_sacked));
821 /* HighRxt MUST NOT be updated */
826 if (hole && seq_lt (sb->high_rxt, hole->start))
827 sb->high_rxt = hole->start;
833 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 snd_una)
835 sack_scoreboard_hole_t *hole;
836 hole = scoreboard_first_hole (sb);
839 snd_una = seq_gt (snd_una, hole->start) ? snd_una : hole->start;
840 sb->cur_rxt_hole = sb->head;
842 sb->high_rxt = snd_una;
843 sb->rescue_rxt = snd_una - 1;
847 scoreboard_init (sack_scoreboard_t * sb)
849 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
850 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
851 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
855 scoreboard_clear (sack_scoreboard_t * sb)
857 sack_scoreboard_hole_t *hole;
858 while ((hole = scoreboard_first_hole (sb)))
860 scoreboard_remove_hole (sb, hole);
862 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
863 ASSERT (pool_elts (sb->holes) == 0);
864 sb->sacked_bytes = 0;
865 sb->last_sacked_bytes = 0;
866 sb->last_bytes_delivered = 0;
871 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
875 * Test that scoreboard is sane after recovery
877 * Returns 1 if scoreboard is empty or if first hole beyond
881 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
883 sack_scoreboard_hole_t *hole;
884 hole = scoreboard_first_hole (&tc->sack_sb);
885 return (!hole || (seq_geq (hole->start, tc->snd_una)
886 && seq_lt (hole->end, tc->snd_una_max)));
890 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
892 sack_scoreboard_t *sb = &tc->sack_sb;
893 sack_block_t *blk, tmp;
894 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
895 u32 blk_index = 0, old_sacked_bytes, hole_index;
898 sb->last_sacked_bytes = 0;
899 sb->last_bytes_delivered = 0;
902 if (!tcp_opts_sack (&tc->rcv_opts)
903 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
906 old_sacked_bytes = sb->sacked_bytes;
908 /* Remove invalid blocks */
909 blk = tc->rcv_opts.sacks;
910 while (blk < vec_end (tc->rcv_opts.sacks))
912 if (seq_lt (blk->start, blk->end)
913 && seq_gt (blk->start, tc->snd_una)
914 && seq_gt (blk->start, ack)
915 && seq_lt (blk->start, tc->snd_una_max)
916 && seq_leq (blk->end, tc->snd_una_max))
921 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
924 /* Add block for cumulative ack */
925 if (seq_gt (ack, tc->snd_una))
927 tmp.start = tc->snd_una;
929 vec_add1 (tc->rcv_opts.sacks, tmp);
932 if (vec_len (tc->rcv_opts.sacks) == 0)
935 tcp_scoreboard_trace_add (tc, ack);
937 /* Make sure blocks are ordered */
938 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
939 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
940 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
942 tmp = tc->rcv_opts.sacks[i];
943 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
944 tc->rcv_opts.sacks[j] = tmp;
947 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
949 /* If no holes, insert the first that covers all outstanding bytes */
950 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
951 tc->snd_una, tc->snd_una_max);
952 sb->tail = scoreboard_hole_index (sb, last_hole);
953 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
954 sb->high_sacked = tmp.end;
958 /* If we have holes but snd_una_max is beyond the last hole, update
960 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
961 last_hole = scoreboard_last_hole (sb);
962 if (seq_gt (tc->snd_una_max, last_hole->end))
964 if (seq_geq (last_hole->start, sb->high_sacked))
966 last_hole->end = tc->snd_una_max;
968 /* New hole after high sacked block */
969 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
971 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
975 /* Keep track of max byte sacked for when the last hole
977 if (seq_gt (tmp.end, sb->high_sacked))
978 sb->high_sacked = tmp.end;
981 /* Walk the holes with the SACK blocks */
982 hole = pool_elt_at_index (sb->holes, sb->head);
983 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
985 blk = &tc->rcv_opts.sacks[blk_index];
986 if (seq_leq (blk->start, hole->start))
988 /* Block covers hole. Remove hole */
989 if (seq_geq (blk->end, hole->end))
991 next_hole = scoreboard_next_hole (sb, hole);
993 /* Byte accounting: snd_una needs to be advanced */
998 if (seq_lt (ack, next_hole->start))
999 sb->snd_una_adv = next_hole->start - ack;
1000 sb->last_bytes_delivered +=
1001 next_hole->start - hole->end;
1005 ASSERT (seq_geq (sb->high_sacked, ack));
1006 sb->snd_una_adv = sb->high_sacked - ack;
1007 sb->last_bytes_delivered += sb->high_sacked - hole->end;
1011 scoreboard_remove_hole (sb, hole);
1014 /* Partial 'head' overlap */
1017 if (seq_gt (blk->end, hole->start))
1019 hole->start = blk->end;
1026 /* Hole must be split */
1027 if (seq_lt (blk->end, hole->end))
1029 hole_index = scoreboard_hole_index (sb, hole);
1030 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
1033 /* Pool might've moved */
1034 hole = scoreboard_get_hole (sb, hole_index);
1035 hole->end = blk->start;
1037 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
1039 else if (seq_lt (blk->start, hole->end))
1041 hole->end = blk->start;
1043 hole = scoreboard_next_hole (sb, hole);
1047 if (pool_elts (sb->holes) == 1)
1049 hole = scoreboard_first_hole (sb);
1050 if (hole->start == ack + sb->snd_una_adv
1051 && hole->end == tc->snd_una_max)
1052 scoreboard_remove_hole (sb, hole);
1055 scoreboard_update_bytes (tc, sb);
1056 sb->last_sacked_bytes = sb->sacked_bytes
1057 - (old_sacked_bytes - sb->last_bytes_delivered);
1058 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
1059 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
1060 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
1061 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
1062 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1063 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1064 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
1065 TCP_EVT_DBG (TCP_EVT_CC_SCOREBOARD, tc);
1069 * Try to update snd_wnd based on feedback received from peer.
1071 * If successful, and new window is 'effectively' 0, activate persist
1075 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1077 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1078 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1079 if (seq_lt (tc->snd_wl1, seq)
1080 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1082 tc->snd_wnd = snd_wnd;
1085 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
1087 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
1089 /* Set persist timer if not set and we just got 0 wnd */
1090 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1091 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1092 tcp_persist_timer_set (tc);
1096 tcp_persist_timer_reset (tc);
1097 if (PREDICT_FALSE (!tcp_in_recovery (tc) && tc->rto_boff > 0))
1100 tcp_update_rto (tc);
1107 * Init loss recovery/fast recovery.
1109 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1110 * updated in @ref tcp_cc_handle_event after fast retransmit
1113 tcp_cc_init_congestion (tcp_connection_t * tc)
1115 tcp_fastrecovery_on (tc);
1116 tc->snd_congestion = tc->snd_una_max;
1117 tc->cwnd_acc_bytes = 0;
1118 tc->snd_rxt_bytes = 0;
1119 tc->prev_ssthresh = tc->ssthresh;
1120 tc->prev_cwnd = tc->cwnd;
1121 tc->cc_algo->congestion (tc);
1122 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
1126 tcp_cc_recovery_exit (tcp_connection_t * tc)
1129 tcp_update_rto (tc);
1131 tc->snd_nxt = tc->snd_una_max;
1133 tcp_recovery_off (tc);
1134 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1138 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
1140 tc->cc_algo->recovered (tc);
1141 tc->snd_rxt_bytes = 0;
1142 tc->rcv_dupacks = 0;
1143 tc->snd_nxt = tc->snd_una_max;
1144 tc->snd_rxt_bytes = 0;
1147 tcp_fastrecovery_off (tc);
1148 tcp_fastrecovery_first_off (tc);
1150 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1154 tcp_cc_congestion_undo (tcp_connection_t * tc)
1156 tc->cwnd = tc->prev_cwnd;
1157 tc->ssthresh = tc->prev_ssthresh;
1158 tc->snd_nxt = tc->snd_una_max;
1159 tc->rcv_dupacks = 0;
1160 if (tcp_in_recovery (tc))
1161 tcp_cc_recovery_exit (tc);
1162 else if (tcp_in_fastrecovery (tc))
1163 tcp_cc_fastrecovery_exit (tc);
1164 ASSERT (tc->rto_boff == 0);
1165 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
1169 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1171 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1173 && tcp_opts_tstamp (&tc->rcv_opts)
1174 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1178 tcp_cc_is_spurious_fast_rxt (tcp_connection_t * tc)
1180 return (tcp_in_fastrecovery (tc)
1181 && tc->cwnd > tc->ssthresh + 3 * tc->snd_mss);
1185 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1187 return (tcp_cc_is_spurious_timeout_rxt (tc)
1188 || tcp_cc_is_spurious_fast_rxt (tc));
1192 tcp_cc_recover (tcp_connection_t * tc)
1194 ASSERT (tcp_in_cong_recovery (tc));
1195 if (tcp_cc_is_spurious_retransmit (tc))
1197 tcp_cc_congestion_undo (tc);
1201 if (tcp_in_recovery (tc))
1202 tcp_cc_recovery_exit (tc);
1203 else if (tcp_in_fastrecovery (tc))
1204 tcp_cc_fastrecovery_exit (tc);
1206 ASSERT (tc->rto_boff == 0);
1207 ASSERT (!tcp_in_cong_recovery (tc));
1208 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1213 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
1215 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1217 /* Congestion avoidance */
1218 tcp_cc_rcv_ack (tc);
1220 /* If a cumulative ack, make sure dupacks is 0 */
1221 tc->rcv_dupacks = 0;
1223 /* When dupacks hits the threshold we only enter fast retransmit if
1224 * cumulative ack covers more than snd_congestion. Should snd_una
1225 * wrap this test may fail under otherwise valid circumstances.
1226 * Therefore, proactively update snd_congestion when wrap detected. */
1228 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1229 && seq_gt (tc->snd_congestion, tc->snd_una)))
1230 tc->snd_congestion = tc->snd_una - 1;
1234 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1236 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1240 tcp_should_fastrecover (tcp_connection_t * tc)
1242 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1243 || tcp_should_fastrecover_sack (tc));
1247 tcp_program_fastretransmit (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1249 if (!(tc->flags & TCP_CONN_FRXT_PENDING))
1251 vec_add1 (wrk->pending_fast_rxt, tc->c_c_index);
1252 tc->flags |= TCP_CONN_FRXT_PENDING;
1257 tcp_do_fastretransmits (tcp_worker_ctx_t * wrk)
1259 u32 *ongoing_fast_rxt, burst_bytes, sent_bytes, thread_index;
1260 u32 max_burst_size, burst_size, n_segs = 0, n_segs_now;
1261 tcp_connection_t *tc;
1265 if (vec_len (wrk->pending_fast_rxt) == 0
1266 && vec_len (wrk->postponed_fast_rxt) == 0)
1269 thread_index = wrk->vm->thread_index;
1270 last_cpu_time = wrk->vm->clib_time.last_cpu_time;
1271 ongoing_fast_rxt = wrk->ongoing_fast_rxt;
1272 vec_append (ongoing_fast_rxt, wrk->postponed_fast_rxt);
1273 vec_append (ongoing_fast_rxt, wrk->pending_fast_rxt);
1275 _vec_len (wrk->postponed_fast_rxt) = 0;
1276 _vec_len (wrk->pending_fast_rxt) = 0;
1278 max_burst_size = VLIB_FRAME_SIZE / vec_len (ongoing_fast_rxt);
1279 max_burst_size = clib_max (max_burst_size, 1);
1281 for (i = 0; i < vec_len (ongoing_fast_rxt); i++)
1283 if (n_segs >= VLIB_FRAME_SIZE)
1285 vec_add1 (wrk->postponed_fast_rxt, ongoing_fast_rxt[i]);
1289 tc = tcp_connection_get (ongoing_fast_rxt[i], thread_index);
1290 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1292 if (!tcp_in_fastrecovery (tc))
1295 burst_size = clib_min (max_burst_size, VLIB_FRAME_SIZE - n_segs);
1296 burst_bytes = transport_connection_tx_pacer_burst (&tc->connection,
1298 burst_size = clib_min (burst_size, burst_bytes / tc->snd_mss);
1301 tcp_program_fastretransmit (wrk, tc);
1305 n_segs_now = tcp_fast_retransmit (wrk, tc, burst_size);
1306 sent_bytes = clib_min (n_segs_now * tc->snd_mss, burst_bytes);
1307 transport_connection_tx_pacer_update_bytes (&tc->connection,
1309 n_segs += n_segs_now;
1311 _vec_len (ongoing_fast_rxt) = 0;
1312 wrk->ongoing_fast_rxt = ongoing_fast_rxt;
1316 * One function to rule them all ... and in the darkness bind them
1319 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1323 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1325 if (tc->bytes_acked)
1327 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1331 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1332 * it account for the bytes that left the network.
1334 else if (is_dack && !tcp_in_recovery (tc))
1336 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1337 ASSERT (tc->snd_una != tc->snd_una_max
1338 || tc->sack_sb.last_sacked_bytes);
1342 /* Pure duplicate ack. If some data got acked, it's handled lower */
1343 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1345 ASSERT (tcp_in_fastrecovery (tc));
1346 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1349 else if (tcp_should_fastrecover (tc))
1353 ASSERT (!tcp_in_fastrecovery (tc));
1355 /* Heuristic to catch potential late dupacks
1356 * after fast retransmit exits */
1357 if (is_dack && tc->snd_una == tc->snd_congestion
1358 && timestamp_leq (tc->rcv_opts.tsecr, tc->tsecr_last_ack))
1360 tc->rcv_dupacks = 0;
1364 tcp_cc_init_congestion (tc);
1365 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1367 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1369 tc->cwnd = tc->ssthresh;
1370 scoreboard_init_high_rxt (&tc->sack_sb, tc->snd_una);
1374 /* Post retransmit update cwnd to ssthresh and account for the
1375 * three segments that have left the network and should've been
1376 * buffered at the receiver XXX */
1377 tc->cwnd = tc->ssthresh + 3 * tc->snd_mss;
1380 /* Constrain rate until we get a partial ack */
1381 pacer_wnd = clib_max (0.1 * tc->cwnd, 2 * tc->snd_mss);
1382 tcp_connection_tx_pacer_reset (tc, pacer_wnd,
1383 0 /* start bucket */ );
1384 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index),
1388 else if (!tc->bytes_acked
1389 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1391 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1397 /* Don't allow entry in fast recovery if still in recovery, for now */
1398 else if (0 && is_dack && tcp_in_recovery (tc))
1400 /* If of of the two conditions lower hold, reset dupacks because
1401 * we're probably after timeout (RFC6582 heuristics).
1402 * If Cumulative ack does not cover more than congestion threshold,
1404 * 1) The following doesn't hold: The congestion window is greater
1405 * than SMSS bytes and the difference between highest_ack
1406 * and prev_highest_ack is at most 4*SMSS bytes
1407 * 2) Echoed timestamp in the last non-dup ack does not equal the
1410 if (seq_leq (tc->snd_una, tc->snd_congestion)
1411 && ((!(tc->cwnd > tc->snd_mss
1412 && tc->bytes_acked <= 4 * tc->snd_mss))
1413 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1415 tc->rcv_dupacks = 0;
1420 if (!tc->bytes_acked)
1424 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1427 * Legitimate ACK. 1) See if we can exit recovery
1430 /* Update the pacing rate. For the first partial ack we move from
1431 * the artificially constrained rate to the one after congestion */
1432 tcp_connection_tx_pacer_update (tc);
1434 if (seq_geq (tc->snd_una, tc->snd_congestion))
1436 tcp_retransmit_timer_update (tc);
1438 /* If spurious return, we've already updated everything */
1439 if (tcp_cc_recover (tc))
1441 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1445 tc->snd_nxt = tc->snd_una_max;
1447 /* Treat as congestion avoidance ack */
1448 tcp_cc_rcv_ack (tc);
1453 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1456 /* XXX limit this only to first partial ack? */
1457 tcp_retransmit_timer_update (tc);
1459 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1460 * reset dupacks to 0. Also needed if in congestion recovery */
1461 tc->rcv_dupacks = 0;
1463 /* Post RTO timeout don't try anything fancy */
1464 if (tcp_in_recovery (tc))
1466 tcp_cc_rcv_ack (tc);
1467 transport_add_tx_event (&tc->connection);
1471 /* Remove retransmitted bytes that have been delivered */
1472 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1474 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1475 >= tc->sack_sb.last_bytes_delivered
1476 || (tc->flags & TCP_CONN_FINSNT));
1478 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1479 * remove sacked bytes delivered */
1480 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1482 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1483 - tc->sack_sb.last_bytes_delivered;
1484 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1485 tc->snd_rxt_bytes -= rxt_delivered;
1489 /* Apparently all retransmitted holes have been acked */
1490 tc->snd_rxt_bytes = 0;
1491 tc->sack_sb.high_rxt = tc->snd_una;
1496 tcp_fastrecovery_first_on (tc);
1497 /* Reuse last bytes delivered to track total bytes acked */
1498 tc->sack_sb.last_bytes_delivered += tc->bytes_acked;
1499 if (tc->snd_rxt_bytes > tc->bytes_acked)
1500 tc->snd_rxt_bytes -= tc->bytes_acked;
1502 tc->snd_rxt_bytes = 0;
1505 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1508 * Since this was a partial ack, try to retransmit some more data
1510 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1514 * Process incoming ACK
1517 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1518 tcp_header_t * th, u32 * error)
1520 u32 prev_snd_wnd, prev_snd_una;
1523 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1525 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1526 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1528 /* When we entered recovery, we reset snd_nxt to snd_una. Seems peer
1529 * still has the data so accept the ack */
1530 if (tcp_in_recovery (tc)
1531 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_congestion))
1533 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1534 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
1535 tc->snd_una_max = tc->snd_nxt;
1539 /* If we have outstanding data and this is within the window, accept it,
1540 * probably retransmit has timed out. Otherwise ACK segment and then
1542 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1544 tcp_program_ack (wrk, tc);
1545 *error = TCP_ERROR_ACK_FUTURE;
1546 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1547 vnet_buffer (b)->tcp.ack_number);
1551 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1552 vnet_buffer (b)->tcp.ack_number);
1554 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1557 /* If old ACK, probably it's an old dupack */
1558 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1560 *error = TCP_ERROR_ACK_OLD;
1561 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1562 vnet_buffer (b)->tcp.ack_number);
1563 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1564 tcp_cc_handle_event (tc, 1);
1565 /* Don't drop yet */
1570 * Looks okay, process feedback
1573 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1574 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1576 prev_snd_wnd = tc->snd_wnd;
1577 prev_snd_una = tc->snd_una;
1578 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1579 vnet_buffer (b)->tcp.ack_number,
1580 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1581 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1582 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1583 tcp_validate_txf_size (tc, tc->bytes_acked);
1585 if (tc->bytes_acked)
1587 tcp_program_dequeue (wrk, tc);
1588 tcp_update_rtt (tc, vnet_buffer (b)->tcp.ack_number);
1591 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1594 * Check if we have congestion event
1597 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1599 tcp_cc_handle_event (tc, is_dack);
1600 if (!tcp_in_cong_recovery (tc))
1602 *error = TCP_ERROR_ACK_DUP;
1603 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1609 * Update congestion control (slow start/congestion avoidance)
1611 tcp_cc_update (tc, b);
1612 *error = TCP_ERROR_ACK_OK;
1617 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1619 if (!tcp_disconnect_pending (tc))
1621 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1622 tcp_disconnect_pending_on (tc);
1627 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1629 u32 thread_index, *pending_disconnects;
1630 tcp_connection_t *tc;
1633 if (!vec_len (wrk->pending_disconnects))
1636 thread_index = wrk->vm->thread_index;
1637 pending_disconnects = wrk->pending_disconnects;
1638 for (i = 0; i < vec_len (pending_disconnects); i++)
1640 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1641 tcp_disconnect_pending_off (tc);
1642 stream_session_disconnect_notify (&tc->connection);
1644 _vec_len (wrk->pending_disconnects) = 0;
1648 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1651 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1652 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1653 /* Account for the FIN if nothing else was received */
1654 if (vnet_buffer (b)->tcp.data_len == 0)
1656 tcp_program_ack (wrk, tc);
1657 tc->state = TCP_STATE_CLOSE_WAIT;
1658 tcp_program_disconnect (wrk, tc);
1659 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1660 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc);
1661 *error = TCP_ERROR_FIN_RCVD;
1665 tcp_sack_vector_is_sane (sack_block_t * sacks)
1668 for (i = 1; i < vec_len (sacks); i++)
1670 if (sacks[i - 1].end == sacks[i].start)
1677 * Build SACK list as per RFC2018.
1679 * Makes sure the first block contains the segment that generated the current
1680 * ACK and the following ones are the ones most recently reported in SACK
1683 * @param tc TCP connection for which the SACK list is updated
1684 * @param start Start sequence number of the newest SACK block
1685 * @param end End sequence of the newest SACK block
1688 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1690 sack_block_t *new_list = 0, *block = 0;
1693 /* If the first segment is ooo add it to the list. Last write might've moved
1694 * rcv_nxt over the first segment. */
1695 if (seq_lt (tc->rcv_nxt, start))
1697 vec_add2 (new_list, block, 1);
1698 block->start = start;
1702 /* Find the blocks still worth keeping. */
1703 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1705 /* Discard if rcv_nxt advanced beyond current block */
1706 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1709 /* Merge or drop if segment overlapped by the new segment */
1710 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1711 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1713 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1714 new_list[0].start = tc->snd_sacks[i].start;
1715 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1716 new_list[0].end = tc->snd_sacks[i].end;
1720 /* Save to new SACK list if we have space. */
1721 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1723 vec_add1 (new_list, tc->snd_sacks[i]);
1727 clib_warning ("sack discarded");
1731 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1733 /* Replace old vector with new one */
1734 vec_free (tc->snd_sacks);
1735 tc->snd_sacks = new_list;
1737 /* Segments should not 'touch' */
1738 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1742 tcp_sack_list_bytes (tcp_connection_t * tc)
1745 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1746 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1750 /** Enqueue data for delivery to application */
1752 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1755 int written, error = TCP_ERROR_ENQUEUED;
1757 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1759 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1760 1 /* queue event */ , 1);
1762 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1764 /* Update rcv_nxt */
1765 if (PREDICT_TRUE (written == data_len))
1767 tc->rcv_nxt += written;
1769 /* If more data written than expected, account for out-of-order bytes. */
1770 else if (written > data_len)
1772 tc->rcv_nxt += written;
1773 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1775 else if (written > 0)
1777 /* We've written something but FIFO is probably full now */
1778 tc->rcv_nxt += written;
1779 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1783 return TCP_ERROR_FIFO_FULL;
1786 /* Update SACK list if need be */
1787 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1789 /* Remove SACK blocks that have been delivered */
1790 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1796 /** Enqueue out-of-order data */
1798 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1801 stream_session_t *s0;
1804 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1807 /* Enqueue out-of-order data with relative offset */
1808 rv = session_enqueue_stream_connection (&tc->connection, b,
1809 vnet_buffer (b)->tcp.seq_number -
1810 tc->rcv_nxt, 0 /* queue event */ ,
1813 /* Nothing written */
1816 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1817 return TCP_ERROR_FIFO_FULL;
1820 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1822 /* Update SACK list if in use */
1823 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1825 ooo_segment_t *newest;
1828 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1830 /* Get the newest segment from the fifo */
1831 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1834 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1835 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1836 start = tc->rcv_nxt + offset;
1837 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1838 tcp_update_sack_list (tc, start, end);
1839 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1840 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1844 return TCP_ERROR_ENQUEUED_OOO;
1848 * Check if ACK could be delayed. If ack can be delayed, it should return
1849 * true for a full frame. If we're always acking return 0.
1852 tcp_can_delack (tcp_connection_t * tc)
1854 /* Send ack if ... */
1856 /* just sent a rcv wnd 0 */
1857 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1858 /* constrained to send ack */
1859 || (tc->flags & TCP_CONN_SNDACK) != 0
1860 /* we're almost out of tx wnd */
1861 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1868 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1870 u32 discard, first = b->current_length;
1871 vlib_main_t *vm = vlib_get_main ();
1873 /* Handle multi-buffer segments */
1874 if (n_bytes_to_drop > b->current_length)
1876 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1880 discard = clib_min (n_bytes_to_drop, b->current_length);
1881 vlib_buffer_advance (b, discard);
1882 b = vlib_get_buffer (vm, b->next_buffer);
1883 n_bytes_to_drop -= discard;
1885 while (n_bytes_to_drop);
1886 if (n_bytes_to_drop > first)
1887 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1890 vlib_buffer_advance (b, n_bytes_to_drop);
1891 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1896 * Receive buffer for connection and handle acks
1898 * It handles both in order or out-of-order data.
1901 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1904 u32 error, n_bytes_to_drop, n_data_bytes;
1906 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1907 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1908 ASSERT (n_data_bytes);
1910 /* Handle out-of-order data */
1911 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1913 /* Old sequence numbers allowed through because they overlapped
1915 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1917 /* Completely in the past (possible retransmit). Ack
1918 * retransmissions since we may not have any data to send */
1919 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1921 tcp_program_ack (wrk, tc);
1922 error = TCP_ERROR_SEGMENT_OLD;
1926 /* Chop off the bytes in the past and see if what is left
1927 * can be enqueued in order */
1928 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1929 n_data_bytes -= n_bytes_to_drop;
1930 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1931 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1933 error = TCP_ERROR_SEGMENT_OLD;
1939 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1940 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1941 tcp_program_dupack (wrk, tc);
1942 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1948 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1949 * segments can be enqueued after fifo tail offset changes. */
1950 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1951 if (tcp_can_delack (tc))
1953 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1954 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1958 tcp_program_ack (wrk, tc);
1966 tcp_header_t tcp_header;
1967 tcp_connection_t tcp_connection;
1971 format_tcp_rx_trace (u8 * s, va_list * args)
1973 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1974 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1975 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1976 u32 indent = format_get_indent (s);
1978 s = format (s, "%U\n%U%U",
1979 format_tcp_header, &t->tcp_header, 128,
1980 format_white_space, indent,
1981 format_tcp_connection, &t->tcp_connection, 1);
1987 format_tcp_rx_trace_short (u8 * s, va_list * args)
1989 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1990 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1991 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1993 s = format (s, "%d -> %d (%U)",
1994 clib_net_to_host_u16 (t->tcp_header.dst_port),
1995 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
1996 t->tcp_connection.state);
2002 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
2003 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
2007 clib_memcpy_fast (&t0->tcp_connection, tc0,
2008 sizeof (t0->tcp_connection));
2012 th0 = tcp_buffer_hdr (b0);
2014 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2018 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2019 vlib_frame_t * frame, u8 is_ip4)
2023 n_left = frame->n_vectors;
2024 from = vlib_frame_vector_args (frame);
2028 tcp_connection_t *tc0;
2035 b0 = vlib_get_buffer (vm, bi0);
2037 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2039 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2040 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2042 th0 = tcp_buffer_hdr (b0);
2043 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2052 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2053 u8 is_ip4, u32 evt, u32 val)
2056 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2058 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2061 #define tcp_maybe_inc_counter(node_id, err, count) \
2063 if (next0 != tcp_next_drop (is_ip4)) \
2064 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2065 tcp6_##node_id##_node.index, is_ip4, err, \
2068 #define tcp_inc_counter(node_id, err, count) \
2069 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2070 tcp6_##node_id##_node.index, is_ip4, \
2072 #define tcp_maybe_inc_err_counter(cnts, err) \
2074 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2076 #define tcp_inc_err_counter(cnts, err, val) \
2080 #define tcp_store_err_counters(node_id, cnts) \
2083 for (i = 0; i < TCP_N_ERROR; i++) \
2085 tcp_inc_counter(node_id, i, cnts[i]); \
2090 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2091 vlib_frame_t * frame, int is_ip4)
2093 u32 thread_index = vm->thread_index, errors = 0;
2094 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2095 u32 n_left_from, *from, *first_buffer;
2096 u16 err_counters[TCP_N_ERROR] = { 0 };
2099 if (node->flags & VLIB_NODE_FLAG_TRACE)
2100 tcp_established_trace_frame (vm, node, frame, is_ip4);
2102 first_buffer = from = vlib_frame_vector_args (frame);
2103 n_left_from = frame->n_vectors;
2105 while (n_left_from > 0)
2107 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2109 tcp_header_t *th0 = 0;
2110 tcp_connection_t *tc0;
2112 if (n_left_from > 1)
2115 pb = vlib_get_buffer (vm, from[1]);
2116 vlib_prefetch_buffer_header (pb, LOAD);
2117 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2124 b0 = vlib_get_buffer (vm, bi0);
2125 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2128 if (PREDICT_FALSE (tc0 == 0))
2130 error0 = TCP_ERROR_INVALID_CONNECTION;
2134 th0 = tcp_buffer_hdr (b0);
2135 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
2136 * dangling reference. */
2137 is_fin = tcp_is_fin (th0);
2139 /* SYNs, FINs and data consume sequence numbers */
2140 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2141 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
2143 /* TODO header prediction fast path */
2145 /* 1-4: check SEQ, RST, SYN */
2146 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2148 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2152 /* 5: check the ACK field */
2153 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2156 /* 6: check the URG bit TODO */
2158 /* 7: process the segment text */
2159 if (vnet_buffer (b0)->tcp.data_len)
2160 error0 = tcp_segment_rcv (wrk, tc0, b0);
2162 /* 8: check the FIN bit */
2163 if (PREDICT_FALSE (is_fin))
2164 tcp_rcv_fin (wrk, tc0, b0, &error0);
2167 tcp_inc_err_counter (err_counters, error0, 1);
2170 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2172 err_counters[TCP_ERROR_EVENT_FIFO_FULL] = errors;
2173 tcp_store_err_counters (established, err_counters);
2174 tcp_handle_postponed_dequeues (wrk);
2175 tcp_handle_disconnects (wrk);
2176 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2178 return frame->n_vectors;
2182 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2183 vlib_frame_t * from_frame)
2185 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2189 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2190 vlib_frame_t * from_frame)
2192 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2196 VLIB_REGISTER_NODE (tcp4_established_node) =
2198 .function = tcp4_established,
2199 .name = "tcp4-established",
2200 /* Takes a vector of packets. */
2201 .vector_size = sizeof (u32),
2202 .n_errors = TCP_N_ERROR,
2203 .error_strings = tcp_error_strings,
2204 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2207 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2208 foreach_tcp_state_next
2211 .format_trace = format_tcp_rx_trace_short,
2215 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
2218 VLIB_REGISTER_NODE (tcp6_established_node) =
2220 .function = tcp6_established,
2221 .name = "tcp6-established",
2222 /* Takes a vector of packets. */
2223 .vector_size = sizeof (u32),
2224 .n_errors = TCP_N_ERROR,
2225 .error_strings = tcp_error_strings,
2226 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2229 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2230 foreach_tcp_state_next
2233 .format_trace = format_tcp_rx_trace_short,
2238 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
2240 vlib_node_registration_t tcp4_syn_sent_node;
2241 vlib_node_registration_t tcp6_syn_sent_node;
2244 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2246 transport_connection_t *tmp = 0;
2253 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2256 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2257 && (tc->state == TCP_STATE_LISTEN
2258 || tc->c_rmt_port == hdr->src_port));
2262 handle = session_lookup_half_open_handle (&tc->connection);
2263 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2264 tc->c_proto, tc->c_is_ip4);
2268 if (tmp->lcl_port == hdr->dst_port
2269 && tmp->rmt_port == hdr->src_port)
2271 TCP_DBG ("half-open is valid!");
2279 * Lookup transport connection
2281 static tcp_connection_t *
2282 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2286 transport_connection_t *tconn;
2287 tcp_connection_t *tc;
2292 ip4 = vlib_buffer_get_current (b);
2293 tcp = ip4_next_header (ip4);
2294 tconn = session_lookup_connection_wt4 (fib_index,
2299 TRANSPORT_PROTO_TCP,
2300 thread_index, &is_filtered);
2301 tc = tcp_get_connection_from_transport (tconn);
2302 ASSERT (tcp_lookup_is_valid (tc, tcp));
2307 ip6 = vlib_buffer_get_current (b);
2308 tcp = ip6_next_header (ip6);
2309 tconn = session_lookup_connection_wt6 (fib_index,
2314 TRANSPORT_PROTO_TCP,
2315 thread_index, &is_filtered);
2316 tc = tcp_get_connection_from_transport (tconn);
2317 ASSERT (tcp_lookup_is_valid (tc, tcp));
2323 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2324 vlib_frame_t * from_frame, int is_ip4)
2326 tcp_main_t *tm = vnet_get_tcp_main ();
2327 u32 n_left_from, *from, *first_buffer, errors = 0;
2328 u32 my_thread_index = vm->thread_index;
2329 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2331 from = first_buffer = vlib_frame_vector_args (from_frame);
2332 n_left_from = from_frame->n_vectors;
2334 while (n_left_from > 0)
2336 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2337 tcp_connection_t *tc0, *new_tc0;
2338 tcp_header_t *tcp0 = 0;
2346 b0 = vlib_get_buffer (vm, bi0);
2348 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2349 if (PREDICT_FALSE (tc0 == 0))
2351 error0 = TCP_ERROR_INVALID_CONNECTION;
2355 /* Half-open completed recently but the connection was't removed
2356 * yet by the owning thread */
2357 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2359 /* Make sure the connection actually exists */
2360 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2361 my_thread_index, is_ip4));
2365 ack0 = vnet_buffer (b0)->tcp.ack_number;
2366 seq0 = vnet_buffer (b0)->tcp.seq_number;
2367 tcp0 = tcp_buffer_hdr (b0);
2369 /* Crude check to see if the connection handle does not match
2370 * the packet. Probably connection just switched to established */
2371 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2372 || tcp0->src_port != tc0->c_rmt_port))
2374 error0 = TCP_ERROR_INVALID_CONNECTION;
2378 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2379 && !tcp_syn (tcp0)))
2381 error0 = TCP_ERROR_SEGMENT_INVALID;
2385 /* SYNs, FINs and data consume sequence numbers */
2386 vnet_buffer (b0)->tcp.seq_end =
2387 seq0 + tcp_is_syn (tcp0) + tcp_is_fin (tcp0) +
2388 vnet_buffer (b0)->tcp.data_len;
2391 * 1. check the ACK bit
2395 * If the ACK bit is set
2396 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2397 * the RST bit is set, if so drop the segment and return)
2398 * <SEQ=SEG.ACK><CTL=RST>
2399 * and discard the segment. Return.
2400 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2404 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2406 if (!tcp_rst (tcp0))
2407 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2408 error0 = TCP_ERROR_RCV_WND;
2412 /* Make sure ACK is valid */
2413 if (seq_gt (tc0->snd_una, ack0))
2415 error0 = TCP_ERROR_ACK_INVALID;
2421 * 2. check the RST bit
2426 /* If ACK is acceptable, signal client that peer is not
2427 * willing to accept connection and drop connection*/
2429 tcp_connection_reset (tc0);
2430 error0 = TCP_ERROR_RST_RCVD;
2435 * 3. check the security and precedence (skipped)
2439 * 4. check the SYN bit
2442 /* No SYN flag. Drop. */
2443 if (!tcp_syn (tcp0))
2445 clib_warning ("not synack");
2446 error0 = TCP_ERROR_SEGMENT_INVALID;
2451 if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1))
2453 clib_warning ("options parse fail");
2454 error0 = TCP_ERROR_OPTIONS;
2458 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2459 * current thread pool. */
2460 pool_get (tm->connections[my_thread_index], new_tc0);
2461 clib_memcpy_fast (new_tc0, tc0, sizeof (*new_tc0));
2462 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2463 new_tc0->c_thread_index = my_thread_index;
2464 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2465 new_tc0->irs = seq0;
2466 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
2467 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2468 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2470 /* If this is not the owning thread, wait for syn retransmit to
2471 * expire and cleanup then */
2472 if (tcp_half_open_connection_cleanup (tc0))
2473 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2475 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2477 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2478 new_tc0->tsval_recent_age = tcp_time_now ();
2481 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2482 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2484 new_tc0->rcv_wscale = 0;
2486 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2487 << new_tc0->snd_wscale;
2488 new_tc0->snd_wl1 = seq0;
2489 new_tc0->snd_wl2 = ack0;
2491 tcp_connection_init_vars (new_tc0);
2493 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2494 if (PREDICT_TRUE (tcp_ack (tcp0)))
2496 /* Our SYN is ACKed: we have iss < ack = snd_una */
2498 /* TODO Dequeue acknowledged segments if we support Fast Open */
2499 new_tc0->snd_una = ack0;
2500 new_tc0->state = TCP_STATE_ESTABLISHED;
2502 /* Make sure las is initialized for the wnd computation */
2503 new_tc0->rcv_las = new_tc0->rcv_nxt;
2505 /* Notify app that we have connection. If session layer can't
2506 * allocate session send reset */
2507 if (session_stream_connect_notify (&new_tc0->connection, 0))
2509 clib_warning ("connect notify fail");
2510 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2511 tcp_connection_cleanup (new_tc0);
2515 new_tc0->tx_fifo_size =
2516 transport_tx_fifo_size (&new_tc0->connection);
2517 /* Update rtt with the syn-ack sample */
2518 tcp_estimate_initial_rtt (new_tc0);
2519 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2520 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2522 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2525 new_tc0->state = TCP_STATE_SYN_RCVD;
2527 /* Notify app that we have connection */
2528 if (session_stream_connect_notify (&new_tc0->connection, 0))
2530 tcp_connection_cleanup (new_tc0);
2531 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2532 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2536 new_tc0->tx_fifo_size =
2537 transport_tx_fifo_size (&new_tc0->connection);
2538 new_tc0->rtt_ts = 0;
2539 tcp_init_snd_vars (new_tc0);
2540 tcp_send_synack (new_tc0);
2541 error0 = TCP_ERROR_SYNS_RCVD;
2545 /* Read data, if any */
2546 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2548 clib_warning ("rcvd data in syn-sent");
2549 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2550 if (error0 == TCP_ERROR_ACK_OK)
2551 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2555 tcp_program_ack (wrk, new_tc0);
2560 tcp_inc_counter (syn_sent, error0, 1);
2561 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2563 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2564 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2565 clib_memcpy_fast (&t0->tcp_connection, tc0,
2566 sizeof (t0->tcp_connection));
2570 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2572 tcp_inc_counter (syn_sent, TCP_ERROR_EVENT_FIFO_FULL, errors);
2573 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2575 return from_frame->n_vectors;
2579 tcp4_syn_sent (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, 1 /* is_ip4 */ );
2586 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2587 vlib_frame_t * from_frame)
2589 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2593 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2595 .function = tcp4_syn_sent,
2596 .name = "tcp4-syn-sent",
2597 /* Takes a vector of packets. */
2598 .vector_size = sizeof (u32),
2599 .n_errors = TCP_N_ERROR,
2600 .error_strings = tcp_error_strings,
2601 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2604 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2605 foreach_tcp_state_next
2608 .format_trace = format_tcp_rx_trace_short,
2612 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2615 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2617 .function = tcp6_syn_sent_rcv,
2618 .name = "tcp6-syn-sent",
2619 /* Takes a vector of packets. */
2620 .vector_size = sizeof (u32),
2621 .n_errors = TCP_N_ERROR,
2622 .error_strings = tcp_error_strings,
2623 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2626 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2627 foreach_tcp_state_next
2630 .format_trace = format_tcp_rx_trace_short,
2634 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2636 vlib_node_registration_t tcp4_rcv_process_node;
2637 vlib_node_registration_t tcp6_rcv_process_node;
2640 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2641 * as per RFC793 p. 64
2644 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2645 vlib_frame_t * from_frame, int is_ip4)
2647 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2648 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2649 u32 n_left_from, *from;
2651 from = first_buffer = vlib_frame_vector_args (from_frame);
2652 n_left_from = from_frame->n_vectors;
2654 while (n_left_from > 0)
2656 u32 bi0, error0 = TCP_ERROR_NONE;
2657 tcp_header_t *tcp0 = 0;
2658 tcp_connection_t *tc0;
2666 b0 = vlib_get_buffer (vm, bi0);
2667 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2669 if (PREDICT_FALSE (tc0 == 0))
2671 error0 = TCP_ERROR_INVALID_CONNECTION;
2675 tcp0 = tcp_buffer_hdr (b0);
2676 is_fin0 = tcp_is_fin (tcp0);
2678 /* SYNs, FINs and data consume sequence numbers */
2679 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2680 + tcp_is_syn (tcp0) + is_fin0 + vnet_buffer (b0)->tcp.data_len;
2684 tcp_connection_t *tmp;
2685 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2687 if (tmp->state != tc0->state)
2689 clib_warning ("state changed");
2695 * Special treatment for CLOSED
2697 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2699 error0 = TCP_ERROR_CONNECTION_CLOSED;
2704 * For all other states (except LISTEN)
2707 /* 1-4: check SEQ, RST, SYN */
2708 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2711 /* 5: check the ACK field */
2714 case TCP_STATE_SYN_RCVD:
2716 * If the segment acknowledgment is not acceptable, form a
2718 * <SEQ=SEG.ACK><CTL=RST>
2721 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2723 TCP_DBG ("connection not accepted");
2724 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2725 error0 = TCP_ERROR_ACK_INVALID;
2729 /* Make sure the ack is exactly right */
2730 if (tc0->rcv_nxt != vnet_buffer (b0)->tcp.seq_number || is_fin0)
2732 error0 = TCP_ERROR_SEGMENT_INVALID;
2733 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2737 /* Update rtt and rto */
2738 tcp_estimate_initial_rtt (tc0);
2740 /* Switch state to ESTABLISHED */
2741 tc0->state = TCP_STATE_ESTABLISHED;
2742 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2744 /* Initialize session variables */
2745 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2746 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2747 << tc0->rcv_opts.wscale;
2748 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2749 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2751 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2752 tcp_retransmit_timer_reset (tc0);
2753 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2754 stream_session_accept_notify (&tc0->connection);
2755 error0 = TCP_ERROR_ACK_OK;
2757 case TCP_STATE_ESTABLISHED:
2758 /* We can get packets in established state here because they
2759 * were enqueued before state change */
2760 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2764 case TCP_STATE_FIN_WAIT_1:
2765 /* In addition to the processing for the ESTABLISHED state, if
2766 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2767 * continue processing in that state. */
2768 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2771 /* Still have to send the FIN */
2772 if (tc0->flags & TCP_CONN_FINPNDG)
2774 /* TX fifo finally drained */
2775 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2778 /* If FIN is ACKed */
2779 else if (tc0->snd_una == tc0->snd_una_max)
2781 tc0->state = TCP_STATE_FIN_WAIT_2;
2782 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2784 /* Stop all retransmit timers because we have nothing more
2785 * to send. Enable waitclose though because we're willing to
2786 * wait for peer's FIN but not indefinitely. */
2787 tcp_connection_timers_reset (tc0);
2788 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2790 /* Don't try to deq the FIN acked */
2791 if (tc0->burst_acked > 1)
2792 stream_session_dequeue_drop (&tc0->connection,
2793 tc0->burst_acked - 1);
2794 tc0->burst_acked = 0;
2797 case TCP_STATE_FIN_WAIT_2:
2798 /* In addition to the processing for the ESTABLISHED state, if
2799 * the retransmission queue is empty, the user's CLOSE can be
2800 * acknowledged ("ok") but do not delete the TCB. */
2801 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2803 tc0->burst_acked = 0;
2805 case TCP_STATE_CLOSE_WAIT:
2806 /* Do the same processing as for the ESTABLISHED state. */
2807 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2810 if (tc0->flags & TCP_CONN_FINPNDG)
2812 /* TX fifo finally drained */
2813 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2816 tcp_connection_timers_reset (tc0);
2817 tc0->state = TCP_STATE_LAST_ACK;
2818 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2822 case TCP_STATE_CLOSING:
2823 /* In addition to the processing for the ESTABLISHED state, if
2824 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2825 * otherwise ignore the segment. */
2826 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2829 tc0->state = TCP_STATE_TIME_WAIT;
2830 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2831 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2835 case TCP_STATE_LAST_ACK:
2836 /* The only thing that [should] arrive in this state is an
2837 * acknowledgment of our FIN. If our FIN is now acknowledged,
2838 * delete the TCB, enter the CLOSED state, and return. */
2840 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2842 error0 = TCP_ERROR_ACK_INVALID;
2845 error0 = TCP_ERROR_ACK_OK;
2846 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2847 /* Apparently our ACK for the peer's FIN was lost */
2848 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2854 tc0->state = TCP_STATE_CLOSED;
2855 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2857 /* Don't free the connection from the data path since
2858 * we can't ensure that we have no packets already enqueued
2859 * to output. Rely instead on the waitclose timer */
2860 tcp_connection_timers_reset (tc0);
2861 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, 1);
2866 case TCP_STATE_TIME_WAIT:
2867 /* The only thing that can arrive in this state is a
2868 * retransmission of the remote FIN. Acknowledge it, and restart
2869 * the 2 MSL timeout. */
2871 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2874 tcp_program_ack (wrk, tc0);
2875 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2883 /* 6: check the URG bit TODO */
2885 /* 7: process the segment text */
2888 case TCP_STATE_ESTABLISHED:
2889 case TCP_STATE_FIN_WAIT_1:
2890 case TCP_STATE_FIN_WAIT_2:
2891 if (vnet_buffer (b0)->tcp.data_len)
2892 error0 = tcp_segment_rcv (wrk, tc0, b0);
2896 case TCP_STATE_CLOSE_WAIT:
2897 case TCP_STATE_CLOSING:
2898 case TCP_STATE_LAST_ACK:
2899 case TCP_STATE_TIME_WAIT:
2900 /* This should not occur, since a FIN has been received from the
2901 * remote side. Ignore the segment text. */
2905 /* 8: check the FIN bit */
2911 case TCP_STATE_ESTABLISHED:
2912 case TCP_STATE_SYN_RCVD:
2913 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2914 tcp_connection_timers_reset (tc0);
2916 stream_session_disconnect_notify (&tc0->connection);
2917 tc0->state = TCP_STATE_CLOSE_WAIT;
2918 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2920 case TCP_STATE_CLOSE_WAIT:
2921 case TCP_STATE_CLOSING:
2922 case TCP_STATE_LAST_ACK:
2925 case TCP_STATE_FIN_WAIT_1:
2926 tc0->state = TCP_STATE_CLOSING;
2927 tcp_program_ack (wrk, tc0);
2928 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2929 /* Wait for ACK but not forever */
2930 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2932 case TCP_STATE_FIN_WAIT_2:
2933 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2934 tc0->state = TCP_STATE_TIME_WAIT;
2935 tcp_connection_timers_reset (tc0);
2936 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2937 tcp_program_ack (wrk, tc0);
2938 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2940 case TCP_STATE_TIME_WAIT:
2941 /* Remain in the TIME-WAIT state. Restart the time-wait
2944 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2947 error0 = TCP_ERROR_FIN_RCVD;
2948 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2952 tcp_inc_counter (rcv_process, error0, 1);
2953 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2955 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2956 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2960 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2962 tcp_inc_counter (rcv_process, TCP_ERROR_EVENT_FIFO_FULL, errors);
2963 tcp_handle_postponed_dequeues (wrk);
2964 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2966 return from_frame->n_vectors;
2970 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2971 vlib_frame_t * from_frame)
2973 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2977 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2978 vlib_frame_t * from_frame)
2980 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2984 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2986 .function = tcp4_rcv_process,
2987 .name = "tcp4-rcv-process",
2988 /* Takes a vector of packets. */
2989 .vector_size = sizeof (u32),
2990 .n_errors = TCP_N_ERROR,
2991 .error_strings = tcp_error_strings,
2992 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2995 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2996 foreach_tcp_state_next
2999 .format_trace = format_tcp_rx_trace_short,
3003 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
3006 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
3008 .function = tcp6_rcv_process,
3009 .name = "tcp6-rcv-process",
3010 /* Takes a vector of packets. */
3011 .vector_size = sizeof (u32),
3012 .n_errors = TCP_N_ERROR,
3013 .error_strings = tcp_error_strings,
3014 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3017 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3018 foreach_tcp_state_next
3021 .format_trace = format_tcp_rx_trace_short,
3025 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
3027 vlib_node_registration_t tcp4_listen_node;
3028 vlib_node_registration_t tcp6_listen_node;
3031 * LISTEN state processing as per RFC 793 p. 65
3034 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3035 vlib_frame_t * from_frame, int is_ip4)
3037 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3038 u32 my_thread_index = vm->thread_index;
3040 from = first_buffer = vlib_frame_vector_args (from_frame);
3041 n_left_from = from_frame->n_vectors;
3043 while (n_left_from > 0)
3048 tcp_header_t *th0 = 0;
3049 tcp_connection_t *lc0;
3052 tcp_connection_t *child0;
3053 u32 error0 = TCP_ERROR_NONE;
3059 b0 = vlib_get_buffer (vm, bi0);
3060 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3064 ip40 = vlib_buffer_get_current (b0);
3065 th0 = ip4_next_header (ip40);
3069 ip60 = vlib_buffer_get_current (b0);
3070 th0 = ip6_next_header (ip60);
3073 /* Create child session. For syn-flood protection use filter */
3075 /* 1. first check for an RST: handled in dispatch */
3076 /* if (tcp_rst (th0))
3080 /* 2. second check for an ACK: handled in dispatch */
3081 /* if (tcp_ack (th0))
3083 tcp_send_reset (b0, is_ip4);
3088 /* 3. check for a SYN (did that already) */
3090 /* Make sure connection wasn't just created */
3091 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3093 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3095 error0 = TCP_ERROR_CREATE_EXISTS;
3099 /* Create child session and send SYN-ACK */
3100 child0 = tcp_connection_new (my_thread_index);
3101 child0->c_lcl_port = th0->dst_port;
3102 child0->c_rmt_port = th0->src_port;
3103 child0->c_is_ip4 = is_ip4;
3104 child0->state = TCP_STATE_SYN_RCVD;
3105 child0->c_fib_index = lc0->c_fib_index;
3109 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3110 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3114 clib_memcpy_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3115 sizeof (ip6_address_t));
3116 clib_memcpy_fast (&child0->c_rmt_ip6, &ip60->src_address,
3117 sizeof (ip6_address_t));
3120 if (tcp_options_parse (th0, &child0->rcv_opts, 1))
3122 clib_warning ("options parse fail");
3126 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3127 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3128 child0->rcv_las = child0->rcv_nxt;
3129 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3131 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3132 * segments are used to initialize PAWS. */
3133 if (tcp_opts_tstamp (&child0->rcv_opts))
3135 child0->tsval_recent = child0->rcv_opts.tsval;
3136 child0->tsval_recent_age = tcp_time_now ();
3139 if (tcp_opts_wscale (&child0->rcv_opts))
3140 child0->snd_wscale = child0->rcv_opts.wscale;
3142 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3143 << child0->snd_wscale;
3144 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3145 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3147 tcp_connection_init_vars (child0);
3148 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
3150 if (stream_session_accept (&child0->connection, lc0->c_s_index,
3153 clib_warning ("session accept fail");
3154 tcp_connection_cleanup (child0);
3155 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3159 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3160 tcp_send_synack (child0);
3161 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
3165 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3167 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3168 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3169 clib_memcpy_fast (&t0->tcp_connection, lc0,
3170 sizeof (t0->tcp_connection));
3173 n_syns += (error0 == TCP_ERROR_NONE);
3176 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3177 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3179 return from_frame->n_vectors;
3183 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3184 vlib_frame_t * from_frame)
3186 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3190 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3191 vlib_frame_t * from_frame)
3193 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3197 VLIB_REGISTER_NODE (tcp4_listen_node) =
3199 .function = tcp4_listen,
3200 .name = "tcp4-listen",
3201 /* Takes a vector of packets. */
3202 .vector_size = sizeof (u32),
3203 .n_errors = TCP_N_ERROR,
3204 .error_strings = tcp_error_strings,
3205 .n_next_nodes = TCP_LISTEN_N_NEXT,
3208 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3209 foreach_tcp_state_next
3212 .format_trace = format_tcp_rx_trace_short,
3216 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
3219 VLIB_REGISTER_NODE (tcp6_listen_node) =
3221 .function = tcp6_listen,
3222 .name = "tcp6-listen",
3223 /* Takes a vector of packets. */
3224 .vector_size = sizeof (u32),
3225 .n_errors = TCP_N_ERROR,
3226 .error_strings = tcp_error_strings,
3227 .n_next_nodes = TCP_LISTEN_N_NEXT,
3230 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3231 foreach_tcp_state_next
3234 .format_trace = format_tcp_rx_trace_short,
3238 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
3240 vlib_node_registration_t tcp4_input_node;
3241 vlib_node_registration_t tcp6_input_node;
3243 typedef enum _tcp_input_next
3245 TCP_INPUT_NEXT_DROP,
3246 TCP_INPUT_NEXT_LISTEN,
3247 TCP_INPUT_NEXT_RCV_PROCESS,
3248 TCP_INPUT_NEXT_SYN_SENT,
3249 TCP_INPUT_NEXT_ESTABLISHED,
3250 TCP_INPUT_NEXT_RESET,
3251 TCP_INPUT_NEXT_PUNT,
3255 #define foreach_tcp4_input_next \
3256 _ (DROP, "ip4-drop") \
3257 _ (LISTEN, "tcp4-listen") \
3258 _ (RCV_PROCESS, "tcp4-rcv-process") \
3259 _ (SYN_SENT, "tcp4-syn-sent") \
3260 _ (ESTABLISHED, "tcp4-established") \
3261 _ (RESET, "tcp4-reset") \
3262 _ (PUNT, "ip4-punt")
3264 #define foreach_tcp6_input_next \
3265 _ (DROP, "ip6-drop") \
3266 _ (LISTEN, "tcp6-listen") \
3267 _ (RCV_PROCESS, "tcp6-rcv-process") \
3268 _ (SYN_SENT, "tcp6-syn-sent") \
3269 _ (ESTABLISHED, "tcp6-established") \
3270 _ (RESET, "tcp6-reset") \
3271 _ (PUNT, "ip6-punt")
3273 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3276 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3277 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3279 tcp_connection_t *tc;
3284 for (i = 0; i < n_bufs; i++)
3286 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3288 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3289 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3291 tcp = vlib_buffer_get_current (bs[i]);
3292 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3298 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3300 if (*error == TCP_ERROR_FILTERED)
3302 *next = TCP_INPUT_NEXT_DROP;
3304 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3306 *next = TCP_INPUT_NEXT_PUNT;
3307 *error = TCP_ERROR_PUNT;
3311 *next = TCP_INPUT_NEXT_RESET;
3312 *error = TCP_ERROR_NO_LISTENER;
3316 static inline tcp_connection_t *
3317 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3320 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3321 int n_advance_bytes, n_data_bytes;
3322 transport_connection_t *tc;
3328 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3329 int ip_hdr_bytes = ip4_header_bytes (ip4);
3330 if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
3332 *error = TCP_ERROR_LENGTH;
3335 tcp = ip4_next_header (ip4);
3336 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3337 n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
3338 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3340 /* Length check. Checksum computed by ipx_local no need to compute again */
3341 if (PREDICT_FALSE (n_data_bytes < 0))
3343 *error = TCP_ERROR_LENGTH;
3347 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3348 &ip4->src_address, tcp->dst_port,
3349 tcp->src_port, TRANSPORT_PROTO_TCP,
3350 thread_index, &is_filtered);
3354 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3355 if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
3357 *error = TCP_ERROR_LENGTH;
3360 tcp = ip6_next_header (ip6);
3361 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3362 n_advance_bytes = tcp_header_bytes (tcp);
3363 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3365 n_advance_bytes += sizeof (ip6[0]);
3367 if (PREDICT_FALSE (n_data_bytes < 0))
3369 *error = TCP_ERROR_LENGTH;
3373 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3374 &ip6->src_address, tcp->dst_port,
3375 tcp->src_port, TRANSPORT_PROTO_TCP,
3376 thread_index, &is_filtered);
3379 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3380 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3381 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3382 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3383 vnet_buffer (b)->tcp.flags = 0;
3385 *error = is_filtered ? TCP_ERROR_FILTERED : *error;
3387 return tcp_get_connection_from_transport (tc);
3391 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3392 vlib_buffer_t * b, u16 * next, u32 * error)
3397 tcp = tcp_buffer_hdr (b);
3398 flags = tcp->flags & filter_flags;
3399 *next = tm->dispatch_table[tc->state][flags].next;
3400 *error = tm->dispatch_table[tc->state][flags].error;
3402 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3403 || *next == TCP_INPUT_NEXT_RESET))
3405 /* Overload tcp flags to store state */
3406 tcp_state_t state = tc->state;
3407 vnet_buffer (b)->tcp.flags = tc->state;
3409 if (*error == TCP_ERROR_DISPATCH)
3410 clib_warning ("disp error state %U flags %U", format_tcp_state,
3411 state, format_tcp_flags, (int) flags);
3416 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3417 vlib_frame_t * frame, int is_ip4)
3419 u32 n_left_from, *from, thread_index = vm->thread_index;
3420 tcp_main_t *tm = vnet_get_tcp_main ();
3421 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3422 u16 nexts[VLIB_FRAME_SIZE], *next;
3424 tcp_set_time_now (tcp_get_worker (thread_index));
3426 from = vlib_frame_vector_args (frame);
3427 n_left_from = frame->n_vectors;
3428 vlib_get_buffers (vm, from, bufs, n_left_from);
3433 while (n_left_from >= 4)
3435 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3436 tcp_connection_t *tc0, *tc1;
3439 vlib_prefetch_buffer_header (b[2], STORE);
3440 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3442 vlib_prefetch_buffer_header (b[3], STORE);
3443 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3446 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3448 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3449 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4);
3451 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3453 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3454 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3456 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3457 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3459 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3460 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3464 if (PREDICT_TRUE (tc0 != 0))
3466 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3467 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3468 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3471 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3473 if (PREDICT_TRUE (tc1 != 0))
3475 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3476 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3477 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3480 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3487 while (n_left_from > 0)
3489 tcp_connection_t *tc0;
3490 u32 error0 = TCP_ERROR_NO_LISTENER;
3492 if (n_left_from > 1)
3494 vlib_prefetch_buffer_header (b[1], STORE);
3495 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3498 next[0] = TCP_INPUT_NEXT_DROP;
3499 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3500 if (PREDICT_TRUE (tc0 != 0))
3502 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3503 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3504 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3507 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3514 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3515 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3517 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3518 return frame->n_vectors;
3522 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3523 vlib_frame_t * from_frame)
3525 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3529 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3530 vlib_frame_t * from_frame)
3532 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3536 VLIB_REGISTER_NODE (tcp4_input_node) =
3538 .function = tcp4_input,
3539 .name = "tcp4-input",
3540 /* Takes a vector of packets. */
3541 .vector_size = sizeof (u32),
3542 .n_errors = TCP_N_ERROR,
3543 .error_strings = tcp_error_strings,
3544 .n_next_nodes = TCP_INPUT_N_NEXT,
3547 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3548 foreach_tcp4_input_next
3551 .format_buffer = format_tcp_header,
3552 .format_trace = format_tcp_rx_trace,
3556 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3559 VLIB_REGISTER_NODE (tcp6_input_node) =
3561 .function = tcp6_input,
3562 .name = "tcp6-input",
3563 /* Takes a vector of packets. */
3564 .vector_size = sizeof (u32),
3565 .n_errors = TCP_N_ERROR,
3566 .error_strings = tcp_error_strings,
3567 .n_next_nodes = TCP_INPUT_N_NEXT,
3570 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3571 foreach_tcp6_input_next
3574 .format_buffer = format_tcp_header,
3575 .format_trace = format_tcp_rx_trace,
3579 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3582 tcp_dispatch_table_init (tcp_main_t * tm)
3585 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3586 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3588 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3589 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3592 #define _(t,f,n,e) \
3594 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3595 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3598 /* SYNs for new connections -> tcp-listen. */
3599 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3600 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3601 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_RST_RCVD);
3602 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3604 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3605 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3606 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3607 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3609 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3610 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3612 /* SYN-ACK for a SYN */
3613 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3615 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3616 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3617 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3619 /* ACK for for established connection -> tcp-established. */
3620 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3621 /* FIN for for established connection -> tcp-established. */
3622 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3623 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3625 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3626 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3628 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3629 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3631 /* ACK or FIN-ACK to our FIN */
3632 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3633 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3635 /* FIN in reply to our FIN from the other side */
3636 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3637 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3638 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3639 /* FIN confirming that the peer (app) has closed */
3640 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3641 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3642 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3644 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3645 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3647 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3648 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3649 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3651 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3652 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3653 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3654 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3656 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3657 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3658 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3659 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3660 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3661 TCP_ERROR_CONNECTION_CLOSED);
3665 static clib_error_t *
3666 tcp_input_init (vlib_main_t * vm)
3668 clib_error_t *error = 0;
3669 tcp_main_t *tm = vnet_get_tcp_main ();
3671 if ((error = vlib_call_init_function (vm, tcp_init)))
3674 /* Initialize dispatch table. */
3675 tcp_dispatch_table_init (tm);
3680 VLIB_INIT_FUNCTION (tcp_input_init);
3683 * fd.io coding-style-patch-verification: ON
3686 * eval: (c-set-style "gnu")