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 * @return -1 if parsing failed
127 tcp_options_parse (tcp_header_t * th, tcp_options_t * to)
130 u8 opt_len, opts_len, kind;
134 opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t);
135 data = (const u8 *) (th + 1);
137 /* Zero out all flags but those set in SYN */
138 to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE
139 | TCP_OPTS_FLAG_SACK);
141 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
145 /* Get options length */
146 if (kind == TCP_OPTION_EOL)
148 else if (kind == TCP_OPTION_NOOP)
160 /* weird option length */
161 if (opt_len < 2 || opt_len > opts_len)
169 if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
171 to->flags |= TCP_OPTS_FLAG_MSS;
172 to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
175 case TCP_OPTION_WINDOW_SCALE:
176 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
178 to->flags |= TCP_OPTS_FLAG_WSCALE;
179 to->wscale = data[2];
180 if (to->wscale > TCP_MAX_WND_SCALE)
182 clib_warning ("Illegal window scaling value: %d",
184 to->wscale = TCP_MAX_WND_SCALE;
188 case TCP_OPTION_TIMESTAMP:
189 if (opt_len == TCP_OPTION_LEN_TIMESTAMP)
191 to->flags |= TCP_OPTS_FLAG_TSTAMP;
192 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
193 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
196 case TCP_OPTION_SACK_PERMITTED:
197 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
198 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
200 case TCP_OPTION_SACK_BLOCK:
201 /* If SACK permitted was not advertised or a SYN, break */
202 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
205 /* If too short or not correctly formatted, break */
206 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
209 to->flags |= TCP_OPTS_FLAG_SACK;
210 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
211 vec_reset_length (to->sacks);
212 for (j = 0; j < to->n_sack_blocks; j++)
214 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 8 * j));
215 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 8 * j));
216 vec_add1 (to->sacks, b);
220 /* Nothing to see here */
228 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
229 * timestamp to echo and it's less than tsval_recent, drop segment
230 * but still send an ACK in order to retain TCP's mechanism for detecting
231 * and recovering from half-open connections
233 * Or at least that's what the theory says. It seems that this might not work
234 * very well with packet reordering and fast retransmit. XXX
237 tcp_segment_check_paws (tcp_connection_t * tc)
239 return tcp_opts_tstamp (&tc->rcv_opts) && tc->tsval_recent
240 && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent);
244 * Update tsval recent
247 tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
250 * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
251 * of an incoming segment:
252 * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
253 * then the TSval from the segment is copied to TS.Recent;
254 * otherwise, the TSval is ignored.
256 if (tcp_opts_tstamp (&tc->rcv_opts) && seq_leq (seq, tc->rcv_las)
257 && seq_leq (tc->rcv_las, seq_end))
259 ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval));
260 tc->tsval_recent = tc->rcv_opts.tsval;
261 tc->tsval_recent_age = tcp_time_now ();
266 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
268 * It first verifies if segment has a wrapped sequence number (PAWS) and then
269 * does the processing associated to the first four steps (ignoring security
270 * and precedence): sequence number, rst bit and syn bit checks.
272 * @return 0 if segments passes validation.
275 tcp_segment_validate (vlib_main_t * vm, tcp_connection_t * tc0,
276 vlib_buffer_t * b0, tcp_header_t * th0,
277 u32 * next0, u32 * error0)
279 /* We could get a burst of RSTs interleaved with acks */
280 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
282 tcp_send_reset (tc0);
283 *error0 = TCP_ERROR_CONNECTION_CLOSED;
287 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
289 *error0 = TCP_ERROR_SEGMENT_INVALID;
293 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts)))
295 clib_warning ("options parse error");
296 *error0 = TCP_ERROR_OPTIONS;
300 if (PREDICT_FALSE (tcp_segment_check_paws (tc0)))
302 *error0 = TCP_ERROR_PAWS;
304 clib_warning ("paws failed\n%U", format_tcp_connection, tc0, 2);
305 TCP_EVT_DBG (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
306 vnet_buffer (b0)->tcp.seq_end);
308 /* If it just so happens that a segment updates tsval_recent for a
309 * segment over 24 days old, invalidate tsval_recent. */
310 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
313 /* Age isn't reset until we get a valid tsval (bsd inspired) */
314 tc0->tsval_recent = 0;
315 clib_warning ("paws failed - really old segment. REALLY?");
319 /* Drop after ack if not rst */
322 tcp_make_ack (tc0, b0);
323 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
330 /* 1st: check sequence number */
331 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
332 vnet_buffer (b0)->tcp.seq_end))
334 *error0 = TCP_ERROR_RCV_WND;
335 /* If our window is 0 and the packet is in sequence, let it pass
336 * through for ack processing. It should be dropped later. */
337 if (!(tc0->rcv_wnd == 0
338 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number))
340 /* If not RST, send dup ack */
343 tcp_make_ack (tc0, b0);
344 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
351 /* 2nd: check the RST bit */
352 if (PREDICT_FALSE (tcp_rst (th0)))
354 tcp_connection_reset (tc0);
355 *error0 = TCP_ERROR_RST_RCVD;
359 /* 3rd: check security and precedence (skip) */
361 /* 4th: check the SYN bit */
362 if (PREDICT_FALSE (tcp_syn (th0)))
364 /* TODO implement RFC 5961 */
365 if (tc0->state == TCP_STATE_SYN_RCVD)
367 tcp_make_synack (tc0, b0);
368 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0, 0);
372 tcp_make_ack (tc0, b0);
373 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, tc0);
378 /* If segment in window, save timestamp */
379 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
380 vnet_buffer (b0)->tcp.seq_end);
384 *next0 = tcp_next_drop (tc0->c_is_ip4);
387 *next0 = tcp_next_output (tc0->c_is_ip4);
392 tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0)
394 /* SND.UNA =< SEG.ACK =< SND.NXT */
395 return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number)
396 && seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt));
400 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
402 * Note that although the original article, srtt and rttvar are scaled
403 * to minimize round-off errors, here we don't. Instead, we rely on
404 * better precision time measurements.
406 * TODO support us rtt resolution
409 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
415 err = mrtt - tc->srtt;
417 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
418 * The increase should be bound */
419 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
420 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
421 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
425 /* First measurement. */
427 tc->rttvar = mrtt >> 1;
432 tcp_update_rto (tcp_connection_t * tc)
434 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
435 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
439 * Update RTT estimate and RTO timer
441 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
442 * timing. Middle boxes are known to fiddle with TCP options so we
443 * should give higher priority to ACK timing.
445 * This should be called only if previously sent bytes have been acked.
447 * return 1 if valid rtt 0 otherwise
450 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
454 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
455 * RTT because they're ambiguous. */
456 if (tcp_in_cong_recovery (tc) || tc->sack_sb.sacked_bytes)
458 if (tcp_in_recovery (tc))
463 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
465 tc->mrtt_us = tcp_time_now_us (tc->c_thread_index) - tc->rtt_ts;
466 mrtt = clib_max ((u32) (tc->mrtt_us * THZ), 1);
468 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
469 * snd_una, i.e., the left side of the send window:
470 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
471 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
473 mrtt = clib_max (tcp_time_now () - tc->rcv_opts.tsecr, 1);
476 /* Ignore dubious measurements */
477 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
480 tcp_estimate_rtt (tc, mrtt);
484 /* Allow measuring of a new RTT */
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 * Dequeue bytes that have been acked and while at it update RTT estimates.
499 tcp_dequeue_acked (tcp_connection_t * tc, u32 ack)
501 /* Dequeue the newly ACKed add SACKed bytes */
502 stream_session_dequeue_drop (&tc->connection,
503 tc->bytes_acked + tc->sack_sb.snd_una_adv);
505 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
507 /* Update rtt and rto */
508 tcp_update_rtt (tc, ack);
510 /* If everything has been acked, stop retransmit timer
511 * otherwise update. */
512 tcp_retransmit_timer_update (tc);
516 * Check if duplicate ack as per RFC5681 Sec. 2
519 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
522 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
523 && seq_gt (tc->snd_una_max, tc->snd_una)
524 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
525 && (prev_snd_wnd == tc->snd_wnd));
529 * Checks if ack is a congestion control event.
532 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
533 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
535 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
536 * defined to be 'duplicate' */
537 *is_dack = tc->sack_sb.last_sacked_bytes
538 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
540 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
544 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
546 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
547 return hole - sb->holes;
551 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
553 return hole->end - hole->start;
556 sack_scoreboard_hole_t *
557 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
559 if (index != TCP_INVALID_SACK_HOLE_INDEX)
560 return pool_elt_at_index (sb->holes, index);
564 sack_scoreboard_hole_t *
565 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
567 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
568 return pool_elt_at_index (sb->holes, hole->next);
572 sack_scoreboard_hole_t *
573 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
575 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
576 return pool_elt_at_index (sb->holes, hole->prev);
580 sack_scoreboard_hole_t *
581 scoreboard_first_hole (sack_scoreboard_t * sb)
583 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
584 return pool_elt_at_index (sb->holes, sb->head);
588 sack_scoreboard_hole_t *
589 scoreboard_last_hole (sack_scoreboard_t * sb)
591 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
592 return pool_elt_at_index (sb->holes, sb->tail);
597 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
599 sack_scoreboard_hole_t *next, *prev;
601 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
603 next = pool_elt_at_index (sb->holes, hole->next);
604 next->prev = hole->prev;
608 sb->tail = hole->prev;
611 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
613 prev = pool_elt_at_index (sb->holes, hole->prev);
614 prev->next = hole->next;
618 sb->head = hole->next;
621 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
622 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
624 /* Poison the entry */
626 clib_memset (hole, 0xfe, sizeof (*hole));
628 pool_put (sb->holes, hole);
631 static sack_scoreboard_hole_t *
632 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
635 sack_scoreboard_hole_t *hole, *next, *prev;
638 pool_get (sb->holes, hole);
639 clib_memset (hole, 0, sizeof (*hole));
643 hole_index = scoreboard_hole_index (sb, hole);
645 prev = scoreboard_get_hole (sb, prev_index);
648 hole->prev = prev_index;
649 hole->next = prev->next;
651 if ((next = scoreboard_next_hole (sb, hole)))
652 next->prev = hole_index;
654 sb->tail = hole_index;
656 prev->next = hole_index;
660 sb->head = hole_index;
661 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
662 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
669 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
671 sack_scoreboard_hole_t *left, *right;
672 u32 bytes = 0, blks = 0;
675 sb->sacked_bytes = 0;
676 left = scoreboard_last_hole (sb);
680 if (seq_gt (sb->high_sacked, left->end))
682 bytes = sb->high_sacked - left->end;
686 while ((right = left)
687 && bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
688 && blks < TCP_DUPACK_THRESHOLD
689 /* left not updated if above conditions fail */
690 && (left = scoreboard_prev_hole (sb, right)))
692 bytes += right->start - left->end;
696 /* left is first lost */
701 sb->lost_bytes += scoreboard_hole_bytes (right);
703 left = scoreboard_prev_hole (sb, right);
705 bytes += right->start - left->end;
707 while ((right = left));
710 sb->sacked_bytes = bytes;
714 * Figure out the next hole to retransmit
716 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
718 sack_scoreboard_hole_t *
719 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
720 sack_scoreboard_hole_t * start,
722 u8 * can_rescue, u8 * snd_limited)
724 sack_scoreboard_hole_t *hole = 0;
726 hole = start ? start : scoreboard_first_hole (sb);
727 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
728 hole = scoreboard_next_hole (sb, hole);
730 /* Nothing, return */
733 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
737 /* Rule (1): if higher than rxt, less than high_sacked and lost */
738 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
740 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
744 /* Rule (2): output takes care of transmitting new data */
745 if (!have_sent_1_smss)
748 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
750 /* Rule (3): if hole not lost */
751 else if (seq_lt (hole->start, sb->high_sacked))
754 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
756 /* Rule (4): if hole beyond high_sacked */
759 ASSERT (seq_geq (hole->start, sb->high_sacked));
762 /* HighRxt MUST NOT be updated */
767 if (hole && seq_lt (sb->high_rxt, hole->start))
768 sb->high_rxt = hole->start;
774 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 seq)
776 sack_scoreboard_hole_t *hole;
777 hole = scoreboard_first_hole (sb);
780 seq = seq_gt (seq, hole->start) ? seq : hole->start;
781 sb->cur_rxt_hole = sb->head;
787 scoreboard_init (sack_scoreboard_t * sb)
789 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
790 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
791 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
795 scoreboard_clear (sack_scoreboard_t * sb)
797 sack_scoreboard_hole_t *hole;
798 while ((hole = scoreboard_first_hole (sb)))
800 scoreboard_remove_hole (sb, hole);
802 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
803 ASSERT (pool_elts (sb->holes) == 0);
804 sb->sacked_bytes = 0;
805 sb->last_sacked_bytes = 0;
806 sb->last_bytes_delivered = 0;
811 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
815 * Test that scoreboard is sane after recovery
817 * Returns 1 if scoreboard is empty or if first hole beyond
821 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
823 sack_scoreboard_hole_t *hole;
824 hole = scoreboard_first_hole (&tc->sack_sb);
825 return (!hole || (seq_geq (hole->start, tc->snd_una)
826 && seq_lt (hole->end, tc->snd_una_max)));
830 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
832 sack_scoreboard_t *sb = &tc->sack_sb;
833 sack_block_t *blk, tmp;
834 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
835 u32 blk_index = 0, old_sacked_bytes, hole_index;
838 sb->last_sacked_bytes = 0;
839 sb->last_bytes_delivered = 0;
842 if (!tcp_opts_sack (&tc->rcv_opts)
843 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
846 old_sacked_bytes = sb->sacked_bytes;
848 /* Remove invalid blocks */
849 blk = tc->rcv_opts.sacks;
850 while (blk < vec_end (tc->rcv_opts.sacks))
852 if (seq_lt (blk->start, blk->end)
853 && seq_gt (blk->start, tc->snd_una)
854 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_una_max))
859 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
862 /* Add block for cumulative ack */
863 if (seq_gt (ack, tc->snd_una))
865 tmp.start = tc->snd_una;
867 vec_add1 (tc->rcv_opts.sacks, tmp);
870 if (vec_len (tc->rcv_opts.sacks) == 0)
873 tcp_scoreboard_trace_add (tc, ack);
875 /* Make sure blocks are ordered */
876 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
877 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
878 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
880 tmp = tc->rcv_opts.sacks[i];
881 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
882 tc->rcv_opts.sacks[j] = tmp;
885 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
887 /* If no holes, insert the first that covers all outstanding bytes */
888 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
889 tc->snd_una, tc->snd_una_max);
890 sb->tail = scoreboard_hole_index (sb, last_hole);
891 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
892 sb->high_sacked = tmp.end;
896 /* If we have holes but snd_una_max is beyond the last hole, update
898 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
899 last_hole = scoreboard_last_hole (sb);
900 if (seq_gt (tc->snd_una_max, last_hole->end))
902 if (seq_geq (last_hole->start, sb->high_sacked))
904 last_hole->end = tc->snd_una_max;
906 /* New hole after high sacked block */
907 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
909 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
913 /* Keep track of max byte sacked for when the last hole
915 if (seq_gt (tmp.end, sb->high_sacked))
916 sb->high_sacked = tmp.end;
919 /* Walk the holes with the SACK blocks */
920 hole = pool_elt_at_index (sb->holes, sb->head);
921 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
923 blk = &tc->rcv_opts.sacks[blk_index];
924 if (seq_leq (blk->start, hole->start))
926 /* Block covers hole. Remove hole */
927 if (seq_geq (blk->end, hole->end))
929 next_hole = scoreboard_next_hole (sb, hole);
931 /* Byte accounting: snd_una needs to be advanced */
936 if (seq_lt (ack, next_hole->start))
937 sb->snd_una_adv = next_hole->start - ack;
938 sb->last_bytes_delivered +=
939 next_hole->start - hole->end;
943 ASSERT (seq_geq (sb->high_sacked, ack));
944 sb->snd_una_adv = sb->high_sacked - ack;
945 sb->last_bytes_delivered += sb->high_sacked - hole->end;
949 scoreboard_remove_hole (sb, hole);
952 /* Partial 'head' overlap */
955 if (seq_gt (blk->end, hole->start))
957 hole->start = blk->end;
964 /* Hole must be split */
965 if (seq_lt (blk->end, hole->end))
967 hole_index = scoreboard_hole_index (sb, hole);
968 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
971 /* Pool might've moved */
972 hole = scoreboard_get_hole (sb, hole_index);
973 hole->end = blk->start;
975 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
977 else if (seq_lt (blk->start, hole->end))
979 hole->end = blk->start;
981 hole = scoreboard_next_hole (sb, hole);
985 if (pool_elts (sb->holes) == 1)
987 hole = scoreboard_first_hole (sb);
988 if (hole->start == ack + sb->snd_una_adv
989 && hole->end == tc->snd_una_max)
990 scoreboard_remove_hole (sb, hole);
993 scoreboard_update_bytes (tc, sb);
994 sb->last_sacked_bytes = sb->sacked_bytes
995 - (old_sacked_bytes - sb->last_bytes_delivered);
996 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
997 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
998 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
999 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
1000 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1001 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1002 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
1003 TCP_EVT_DBG (TCP_EVT_CC_SCOREBOARD, tc);
1007 * Try to update snd_wnd based on feedback received from peer.
1009 * If successful, and new window is 'effectively' 0, activate persist
1013 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1015 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1016 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1017 if (seq_lt (tc->snd_wl1, seq)
1018 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1020 tc->snd_wnd = snd_wnd;
1023 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
1025 if (tc->snd_wnd < tc->snd_mss)
1027 /* Set persist timer if not set and we just got 0 wnd */
1028 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1029 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1030 tcp_persist_timer_set (tc);
1034 tcp_persist_timer_reset (tc);
1035 if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
1038 tcp_update_rto (tc);
1045 * Init loss recovery/fast recovery.
1047 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1048 * updated in @ref tcp_cc_handle_event after fast retransmit
1051 tcp_cc_init_congestion (tcp_connection_t * tc)
1053 tcp_fastrecovery_on (tc);
1054 tc->snd_congestion = tc->snd_una_max;
1055 tc->cwnd_acc_bytes = 0;
1056 tc->snd_rxt_bytes = 0;
1057 tc->prev_ssthresh = tc->ssthresh;
1058 tc->prev_cwnd = tc->cwnd;
1059 tc->cc_algo->congestion (tc);
1060 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
1064 tcp_cc_recovery_exit (tcp_connection_t * tc)
1067 tcp_update_rto (tc);
1069 tc->snd_nxt = tc->snd_una_max;
1070 tcp_recovery_off (tc);
1071 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1075 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
1077 tc->cc_algo->recovered (tc);
1078 tc->snd_rxt_bytes = 0;
1079 tc->rcv_dupacks = 0;
1080 tc->snd_nxt = tc->snd_una_max;
1081 tc->snd_rxt_bytes = 0;
1083 tcp_fastrecovery_off (tc);
1084 tcp_fastrecovery_1_smss_off (tc);
1085 tcp_fastrecovery_first_off (tc);
1087 /* Update pacer because our cwnd changed. Also makes sure
1088 * that we recompute the max burst size */
1089 tcp_update_pacer (tc);
1091 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1095 tcp_cc_congestion_undo (tcp_connection_t * tc)
1097 tc->cwnd = tc->prev_cwnd;
1098 tc->ssthresh = tc->prev_ssthresh;
1099 tc->snd_nxt = tc->snd_una_max;
1100 tc->rcv_dupacks = 0;
1101 if (tcp_in_recovery (tc))
1102 tcp_cc_recovery_exit (tc);
1103 else if (tcp_in_fastrecovery (tc))
1104 tcp_cc_fastrecovery_exit (tc);
1105 ASSERT (tc->rto_boff == 0);
1106 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
1110 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1112 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1114 && tcp_opts_tstamp (&tc->rcv_opts)
1115 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1119 tcp_cc_is_spurious_fast_rxt (tcp_connection_t * tc)
1121 return (tcp_in_fastrecovery (tc)
1122 && tc->cwnd > tc->ssthresh + 3 * tc->snd_mss);
1126 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1128 return (tcp_cc_is_spurious_timeout_rxt (tc)
1129 || tcp_cc_is_spurious_fast_rxt (tc));
1133 tcp_cc_recover (tcp_connection_t * tc)
1135 ASSERT (tcp_in_cong_recovery (tc));
1136 if (tcp_cc_is_spurious_retransmit (tc))
1138 tcp_cc_congestion_undo (tc);
1142 if (tcp_in_recovery (tc))
1143 tcp_cc_recovery_exit (tc);
1144 else if (tcp_in_fastrecovery (tc))
1145 tcp_cc_fastrecovery_exit (tc);
1147 ASSERT (tc->rto_boff == 0);
1148 ASSERT (!tcp_in_cong_recovery (tc));
1149 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1154 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
1156 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1158 /* Congestion avoidance */
1159 tcp_cc_rcv_ack (tc);
1161 /* If a cumulative ack, make sure dupacks is 0 */
1162 tc->rcv_dupacks = 0;
1164 /* When dupacks hits the threshold we only enter fast retransmit if
1165 * cumulative ack covers more than snd_congestion. Should snd_una
1166 * wrap this test may fail under otherwise valid circumstances.
1167 * Therefore, proactively update snd_congestion when wrap detected. */
1169 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1170 && seq_gt (tc->snd_congestion, tc->snd_una)))
1171 tc->snd_congestion = tc->snd_una - 1;
1175 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1177 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1181 tcp_should_fastrecover (tcp_connection_t * tc)
1183 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1184 || tcp_should_fastrecover_sack (tc));
1188 tcp_program_fastretransmit (tcp_connection_t * tc)
1190 tcp_worker_ctx_t *wrk = &tcp_main.wrk_ctx[tc->c_thread_index];
1191 if (!(tc->flags & TCP_CONN_FRXT_PENDING))
1193 vec_add1 (wrk->pending_fast_rxt, tc->c_c_index);
1194 tc->flags |= TCP_CONN_FRXT_PENDING;
1199 tcp_do_fastretransmits (u32 thread_index)
1201 tcp_worker_ctx_t *wrk = &tcp_main.wrk_ctx[thread_index];
1202 u32 max_burst_size, burst_size, n_segs = 0;
1203 tcp_connection_t *tc;
1206 if (vec_len (wrk->pending_fast_rxt) == 0)
1209 vec_append (wrk->ongoing_fast_rxt, wrk->pending_fast_rxt);
1210 vec_reset_length (wrk->pending_fast_rxt);
1212 max_burst_size = VLIB_FRAME_SIZE / vec_len (wrk->ongoing_fast_rxt);
1213 max_burst_size = clib_max (max_burst_size, 1);
1215 for (i = 0; i < vec_len (wrk->ongoing_fast_rxt); i++)
1217 tc = tcp_connection_get (wrk->ongoing_fast_rxt[i], thread_index);
1218 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1220 if (!tcp_in_fastrecovery (tc))
1223 /* TODO tx pacer instead of this */
1224 if (n_segs >= VLIB_FRAME_SIZE)
1226 tcp_program_fastretransmit (tc);
1230 burst_size = clib_min (max_burst_size, VLIB_FRAME_SIZE - n_segs);
1232 if (tc->cwnd > tc->ssthresh + 3 * tc->snd_mss)
1234 /* The first segment MUST be retransmitted */
1235 if (tcp_retransmit_first_unacked (tc))
1237 tcp_program_fastretransmit (tc);
1241 /* Post retransmit update cwnd to ssthresh and account for the
1242 * three segments that have left the network and should've been
1243 * buffered at the receiver XXX */
1244 tc->cwnd = tc->ssthresh + 3 * tc->snd_mss;
1246 /* If cwnd allows, send more data */
1247 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1249 scoreboard_init_high_rxt (&tc->sack_sb,
1250 tc->snd_una + tc->snd_mss);
1251 tc->sack_sb.rescue_rxt = tc->snd_una - 1;
1252 n_segs += tcp_fast_retransmit_sack (tc, burst_size);
1256 n_segs += tcp_fast_retransmit_no_sack (tc, burst_size);
1260 n_segs += tcp_fast_retransmit (tc, burst_size);
1262 vec_reset_length (wrk->ongoing_fast_rxt);
1266 * One function to rule them all ... and in the darkness bind them
1269 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1273 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1275 if (tc->bytes_acked)
1277 tcp_program_fastretransmit (tc);
1281 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1282 * it account for the bytes that left the network.
1284 else if (is_dack && !tcp_in_recovery (tc))
1286 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1287 ASSERT (tc->snd_una != tc->snd_una_max
1288 || tc->sack_sb.last_sacked_bytes);
1292 /* Pure duplicate ack. If some data got acked, it's handled lower */
1293 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1295 ASSERT (tcp_in_fastrecovery (tc));
1296 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1299 else if (tcp_should_fastrecover (tc))
1301 ASSERT (!tcp_in_fastrecovery (tc));
1303 /* Heuristic to catch potential late dupacks
1304 * after fast retransmit exits */
1305 if (is_dack && tc->snd_una == tc->snd_congestion
1306 && timestamp_leq (tc->rcv_opts.tsecr, tc->tsecr_last_ack))
1308 tc->rcv_dupacks = 0;
1312 tcp_cc_init_congestion (tc);
1313 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1315 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1316 tc->sack_sb.high_rxt = tc->snd_una;
1318 tcp_program_fastretransmit (tc);
1321 else if (!tc->bytes_acked
1322 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1324 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1330 /* Don't allow entry in fast recovery if still in recovery, for now */
1331 else if (0 && is_dack && tcp_in_recovery (tc))
1333 /* If of of the two conditions lower hold, reset dupacks because
1334 * we're probably after timeout (RFC6582 heuristics).
1335 * If Cumulative ack does not cover more than congestion threshold,
1337 * 1) The following doesn't hold: The congestion window is greater
1338 * than SMSS bytes and the difference between highest_ack
1339 * and prev_highest_ack is at most 4*SMSS bytes
1340 * 2) Echoed timestamp in the last non-dup ack does not equal the
1343 if (seq_leq (tc->snd_una, tc->snd_congestion)
1344 && ((!(tc->cwnd > tc->snd_mss
1345 && tc->bytes_acked <= 4 * tc->snd_mss))
1346 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1348 tc->rcv_dupacks = 0;
1353 if (!tc->bytes_acked)
1357 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1360 * Legitimate ACK. 1) See if we can exit recovery
1363 if (seq_geq (tc->snd_una, tc->snd_congestion))
1365 tcp_retransmit_timer_update (tc);
1367 /* If spurious return, we've already updated everything */
1368 if (tcp_cc_recover (tc))
1370 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1374 tc->snd_nxt = tc->snd_una_max;
1376 /* Treat as congestion avoidance ack */
1377 tcp_cc_rcv_ack (tc);
1382 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1385 /* XXX limit this only to first partial ack? */
1386 tcp_retransmit_timer_force_update (tc);
1388 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1389 * reset dupacks to 0. Also needed if in congestion recovery */
1390 tc->rcv_dupacks = 0;
1392 /* Post RTO timeout don't try anything fancy */
1393 if (tcp_in_recovery (tc))
1395 tcp_cc_rcv_ack (tc);
1396 transport_add_tx_event (&tc->connection);
1400 /* Remove retransmitted bytes that have been delivered */
1401 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1403 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1404 >= tc->sack_sb.last_bytes_delivered
1405 || (tc->flags & TCP_CONN_FINSNT));
1407 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1408 * remove sacked bytes delivered */
1409 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1411 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1412 - tc->sack_sb.last_bytes_delivered;
1413 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1414 tc->snd_rxt_bytes -= rxt_delivered;
1418 /* Apparently all retransmitted holes have been acked */
1419 tc->snd_rxt_bytes = 0;
1424 if (tc->snd_rxt_bytes > tc->bytes_acked)
1425 tc->snd_rxt_bytes -= tc->bytes_acked;
1427 tc->snd_rxt_bytes = 0;
1430 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1433 * Since this was a partial ack, try to retransmit some more data
1435 tcp_program_fastretransmit (tc);
1439 * Process incoming ACK
1442 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
1443 tcp_header_t * th, u32 * next, u32 * error)
1445 u32 prev_snd_wnd, prev_snd_una;
1448 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1450 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1451 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1453 /* When we entered recovery, we reset snd_nxt to snd_una. Seems peer
1454 * still has the data so accept the ack */
1455 if (tcp_in_recovery (tc)
1456 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_congestion))
1458 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1459 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
1460 tc->snd_una_max = tc->snd_nxt;
1464 /* If we have outstanding data and this is within the window, accept it,
1465 * probably retransmit has timed out. Otherwise ACK segment and then
1467 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1469 tcp_make_ack (tc, b);
1470 *next = tcp_next_output (tc->c_is_ip4);
1471 *error = TCP_ERROR_ACK_INVALID;
1472 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1473 vnet_buffer (b)->tcp.ack_number);
1477 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1478 vnet_buffer (b)->tcp.ack_number);
1480 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1481 *error = TCP_ERROR_ACK_FUTURE;
1484 /* If old ACK, probably it's an old dupack */
1485 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1487 *error = TCP_ERROR_ACK_OLD;
1488 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1489 vnet_buffer (b)->tcp.ack_number);
1490 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1491 tcp_cc_handle_event (tc, 1);
1492 /* Don't drop yet */
1497 * Looks okay, process feedback
1500 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1501 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1503 prev_snd_wnd = tc->snd_wnd;
1504 prev_snd_una = tc->snd_una;
1505 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1506 vnet_buffer (b)->tcp.ack_number,
1507 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1508 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1509 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1510 tcp_validate_txf_size (tc, tc->bytes_acked);
1512 if (tc->bytes_acked)
1513 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
1515 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1518 * Check if we have congestion event
1521 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1523 tcp_cc_handle_event (tc, is_dack);
1524 if (!tcp_in_cong_recovery (tc))
1526 *error = TCP_ERROR_ACK_DUP;
1527 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1533 * Update congestion control (slow start/congestion avoidance)
1535 tcp_cc_update (tc, b);
1536 *error = TCP_ERROR_ACK_OK;
1541 tcp_sack_vector_is_sane (sack_block_t * sacks)
1544 for (i = 1; i < vec_len (sacks); i++)
1546 if (sacks[i - 1].end == sacks[i].start)
1553 * Build SACK list as per RFC2018.
1555 * Makes sure the first block contains the segment that generated the current
1556 * ACK and the following ones are the ones most recently reported in SACK
1559 * @param tc TCP connection for which the SACK list is updated
1560 * @param start Start sequence number of the newest SACK block
1561 * @param end End sequence of the newest SACK block
1564 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1566 sack_block_t *new_list = 0, *block = 0;
1569 /* If the first segment is ooo add it to the list. Last write might've moved
1570 * rcv_nxt over the first segment. */
1571 if (seq_lt (tc->rcv_nxt, start))
1573 vec_add2 (new_list, block, 1);
1574 block->start = start;
1578 /* Find the blocks still worth keeping. */
1579 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1581 /* Discard if rcv_nxt advanced beyond current block */
1582 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1585 /* Merge or drop if segment overlapped by the new segment */
1586 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1587 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1589 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1590 new_list[0].start = tc->snd_sacks[i].start;
1591 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1592 new_list[0].end = tc->snd_sacks[i].end;
1596 /* Save to new SACK list if we have space. */
1597 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1599 vec_add1 (new_list, tc->snd_sacks[i]);
1603 clib_warning ("sack discarded");
1607 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1609 /* Replace old vector with new one */
1610 vec_free (tc->snd_sacks);
1611 tc->snd_sacks = new_list;
1613 /* Segments should not 'touch' */
1614 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1618 tcp_sack_list_bytes (tcp_connection_t * tc)
1621 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1622 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1626 /** Enqueue data for delivery to application */
1628 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1631 int written, error = TCP_ERROR_ENQUEUED;
1633 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1635 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1636 1 /* queue event */ , 1);
1638 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1640 /* Update rcv_nxt */
1641 if (PREDICT_TRUE (written == data_len))
1643 tc->rcv_nxt += written;
1645 /* If more data written than expected, account for out-of-order bytes. */
1646 else if (written > data_len)
1648 tc->rcv_nxt += written;
1650 /* Send ACK confirming the update */
1651 tc->flags |= TCP_CONN_SNDACK;
1652 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1654 else if (written > 0)
1656 /* We've written something but FIFO is probably full now */
1657 tc->rcv_nxt += written;
1659 /* Depending on how fast the app is, all remaining buffers in burst will
1660 * not be enqueued. Inform peer */
1661 tc->flags |= TCP_CONN_SNDACK;
1663 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1667 tc->flags |= TCP_CONN_SNDACK;
1668 return TCP_ERROR_FIFO_FULL;
1671 /* Update SACK list if need be */
1672 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1674 /* Remove SACK blocks that have been delivered */
1675 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1681 /** Enqueue out-of-order data */
1683 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1686 stream_session_t *s0;
1689 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1692 /* Enqueue out-of-order data with relative offset */
1693 rv = session_enqueue_stream_connection (&tc->connection, b,
1694 vnet_buffer (b)->tcp.seq_number -
1695 tc->rcv_nxt, 0 /* queue event */ ,
1698 /* Nothing written */
1701 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1702 return TCP_ERROR_FIFO_FULL;
1705 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1707 /* Update SACK list if in use */
1708 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1710 ooo_segment_t *newest;
1713 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1715 /* Get the newest segment from the fifo */
1716 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1719 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1720 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1721 start = tc->rcv_nxt + offset;
1722 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1723 tcp_update_sack_list (tc, start, end);
1724 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1725 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1729 return TCP_ERROR_ENQUEUED_OOO;
1733 * Check if ACK could be delayed. If ack can be delayed, it should return
1734 * true for a full frame. If we're always acking return 0.
1737 tcp_can_delack (tcp_connection_t * tc)
1739 /* Send ack if ... */
1741 /* just sent a rcv wnd 0 */
1742 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1743 /* constrained to send ack */
1744 || (tc->flags & TCP_CONN_SNDACK) != 0
1745 /* we're almost out of tx wnd */
1746 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1753 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1755 u32 discard, first = b->current_length;
1756 vlib_main_t *vm = vlib_get_main ();
1758 /* Handle multi-buffer segments */
1759 if (n_bytes_to_drop > b->current_length)
1761 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1765 discard = clib_min (n_bytes_to_drop, b->current_length);
1766 vlib_buffer_advance (b, discard);
1767 b = vlib_get_buffer (vm, b->next_buffer);
1768 n_bytes_to_drop -= discard;
1770 while (n_bytes_to_drop);
1771 if (n_bytes_to_drop > first)
1772 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1775 vlib_buffer_advance (b, n_bytes_to_drop);
1776 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1781 * Receive buffer for connection and handle acks
1783 * It handles both in order or out-of-order data.
1786 tcp_segment_rcv (tcp_connection_t * tc, vlib_buffer_t * b, u32 * next0)
1788 u32 error, n_bytes_to_drop, n_data_bytes;
1790 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1791 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1792 ASSERT (n_data_bytes);
1794 /* Handle out-of-order data */
1795 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1797 /* Old sequence numbers allowed through because they overlapped
1799 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1801 /* Completely in the past (possible retransmit). Ack
1802 * retransmissions since we may not have any data to send */
1803 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1805 tcp_make_ack (tc, b);
1806 error = TCP_ERROR_SEGMENT_OLD;
1807 *next0 = tcp_next_output (tc->c_is_ip4);
1811 /* Chop off the bytes in the past and see if what is left
1812 * can be enqueued in order */
1813 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1814 n_data_bytes -= n_bytes_to_drop;
1815 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1816 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1818 error = TCP_ERROR_SEGMENT_OLD;
1819 *next0 = tcp_next_drop (tc->c_is_ip4);
1825 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1826 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1827 *next0 = tcp_next_output (tc->c_is_ip4);
1828 tcp_make_ack (tc, b);
1829 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1830 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1836 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1837 * segments can be enqueued after fifo tail offset changes. */
1838 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1839 if (tcp_can_delack (tc))
1841 *next0 = tcp_next_drop (tc->c_is_ip4);
1842 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1843 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1847 *next0 = tcp_next_output (tc->c_is_ip4);
1848 tcp_make_ack (tc, b);
1856 tcp_header_t tcp_header;
1857 tcp_connection_t tcp_connection;
1861 format_tcp_rx_trace (u8 * s, va_list * args)
1863 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1864 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1865 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1866 u32 indent = format_get_indent (s);
1868 s = format (s, "%U\n%U%U",
1869 format_tcp_header, &t->tcp_header, 128,
1870 format_white_space, indent,
1871 format_tcp_connection, &t->tcp_connection, 1);
1877 format_tcp_rx_trace_short (u8 * s, va_list * args)
1879 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1880 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1881 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1883 s = format (s, "%d -> %d (%U)",
1884 clib_net_to_host_u16 (t->tcp_header.dst_port),
1885 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
1886 t->tcp_connection.state);
1892 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1893 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1897 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1901 th0 = tcp_buffer_hdr (b0);
1903 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1907 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
1908 vlib_frame_t * frame, u8 is_ip4)
1912 n_left = frame->n_vectors;
1913 from = vlib_frame_vector_args (frame);
1917 tcp_connection_t *tc0;
1924 b0 = vlib_get_buffer (vm, bi0);
1926 if (b0->flags & VLIB_BUFFER_IS_TRACED)
1928 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1929 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1931 th0 = tcp_buffer_hdr (b0);
1932 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1941 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
1942 u8 is_ip4, u32 evt, u32 val)
1945 vlib_node_increment_counter (vm, tcp4_node, evt, val);
1947 vlib_node_increment_counter (vm, tcp6_node, evt, val);
1950 #define tcp_maybe_inc_counter(node_id, err, count) \
1952 if (next0 != tcp_next_drop (is_ip4)) \
1953 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1954 tcp6_##node_id##_node.index, is_ip4, err, \
1957 #define tcp_inc_counter(node_id, err, count) \
1958 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1959 tcp6_##node_id##_node.index, is_ip4, \
1961 #define tcp_maybe_inc_err_counter(cnts, err) \
1963 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
1965 #define tcp_inc_err_counter(cnts, err, val) \
1969 #define tcp_store_err_counters(node_id, cnts) \
1972 for (i = 0; i < TCP_N_ERROR; i++) \
1974 tcp_inc_counter(node_id, i, cnts[i]); \
1979 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1980 vlib_frame_t * frame, int is_ip4)
1982 u32 thread_index = vm->thread_index, errors = 0;
1983 u32 n_left_from, next_index, *from, *to_next;
1984 u16 err_counters[TCP_N_ERROR] = { 0 };
1987 if (node->flags & VLIB_NODE_FLAG_TRACE)
1988 tcp_established_trace_frame (vm, node, frame, is_ip4);
1990 from = vlib_frame_vector_args (frame);
1991 n_left_from = frame->n_vectors;
1992 next_index = node->cached_next_index;
1994 while (n_left_from > 0)
1998 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1999 while (n_left_from > 0 && n_left_to_next > 0)
2003 tcp_header_t *th0 = 0;
2004 tcp_connection_t *tc0;
2005 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ACK_OK;
2007 if (n_left_from > 1)
2010 pb = vlib_get_buffer (vm, from[1]);
2011 vlib_prefetch_buffer_header (pb, LOAD);
2012 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2020 n_left_to_next -= 1;
2022 b0 = vlib_get_buffer (vm, bi0);
2023 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2026 if (PREDICT_FALSE (tc0 == 0))
2028 error0 = TCP_ERROR_INVALID_CONNECTION;
2032 th0 = tcp_buffer_hdr (b0);
2033 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
2034 * dangling reference. */
2035 is_fin = tcp_is_fin (th0);
2037 /* SYNs, FINs and data consume sequence numbers */
2038 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2039 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
2041 /* TODO header prediction fast path */
2043 /* 1-4: check SEQ, RST, SYN */
2044 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0,
2047 tcp_maybe_inc_err_counter (err_counters, error0);
2048 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2052 /* 5: check the ACK field */
2053 if (PREDICT_FALSE (tcp_rcv_ack (tc0, b0, th0, &next0, &error0)))
2055 tcp_maybe_inc_err_counter (err_counters, error0);
2059 /* 6: check the URG bit TODO */
2061 /* 7: process the segment text */
2062 if (vnet_buffer (b0)->tcp.data_len)
2064 error0 = tcp_segment_rcv (tc0, b0, &next0);
2065 tcp_maybe_inc_err_counter (err_counters, error0);
2068 /* 8: check the FIN bit */
2069 if (PREDICT_FALSE (is_fin))
2071 /* Enter CLOSE-WAIT and notify session. To avoid lingering
2072 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
2073 /* Account for the FIN if nothing else was received */
2074 if (vnet_buffer (b0)->tcp.data_len == 0)
2076 tcp_make_ack (tc0, b0);
2077 next0 = tcp_next_output (tc0->c_is_ip4);
2078 tc0->state = TCP_STATE_CLOSE_WAIT;
2079 stream_session_disconnect_notify (&tc0->connection);
2080 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
2081 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2082 tcp_inc_err_counter (err_counters, TCP_ERROR_FIN_RCVD, 1);
2086 b0->error = node->errors[error0];
2087 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2088 n_left_to_next, bi0, next0);
2091 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2094 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2096 err_counters[TCP_ERROR_EVENT_FIFO_FULL] = errors;
2097 tcp_store_err_counters (established, err_counters);
2098 tcp_flush_frame_to_output (vm, thread_index, is_ip4);
2100 return frame->n_vectors;
2104 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2105 vlib_frame_t * from_frame)
2107 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2111 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2112 vlib_frame_t * from_frame)
2114 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2118 VLIB_REGISTER_NODE (tcp4_established_node) =
2120 .function = tcp4_established,
2121 .name = "tcp4-established",
2122 /* Takes a vector of packets. */
2123 .vector_size = sizeof (u32),
2124 .n_errors = TCP_N_ERROR,
2125 .error_strings = tcp_error_strings,
2126 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2129 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2130 foreach_tcp_state_next
2133 .format_trace = format_tcp_rx_trace_short,
2137 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
2140 VLIB_REGISTER_NODE (tcp6_established_node) =
2142 .function = tcp6_established,
2143 .name = "tcp6-established",
2144 /* Takes a vector of packets. */
2145 .vector_size = sizeof (u32),
2146 .n_errors = TCP_N_ERROR,
2147 .error_strings = tcp_error_strings,
2148 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2151 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2152 foreach_tcp_state_next
2155 .format_trace = format_tcp_rx_trace_short,
2160 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
2162 vlib_node_registration_t tcp4_syn_sent_node;
2163 vlib_node_registration_t tcp6_syn_sent_node;
2166 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2168 transport_connection_t *tmp = 0;
2175 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2178 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2179 && (tc->state == TCP_STATE_LISTEN
2180 || tc->c_rmt_port == hdr->src_port));
2184 handle = session_lookup_half_open_handle (&tc->connection);
2185 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2186 tc->c_proto, tc->c_is_ip4);
2190 if (tmp->lcl_port == hdr->dst_port
2191 && tmp->rmt_port == hdr->src_port)
2193 TCP_DBG ("half-open is valid!");
2201 * Lookup transport connection
2203 static tcp_connection_t *
2204 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2208 transport_connection_t *tconn;
2209 tcp_connection_t *tc;
2214 ip4 = vlib_buffer_get_current (b);
2215 tcp = ip4_next_header (ip4);
2216 tconn = session_lookup_connection_wt4 (fib_index,
2221 TRANSPORT_PROTO_TCP,
2222 thread_index, &is_filtered);
2223 tc = tcp_get_connection_from_transport (tconn);
2224 ASSERT (tcp_lookup_is_valid (tc, tcp));
2229 ip6 = vlib_buffer_get_current (b);
2230 tcp = ip6_next_header (ip6);
2231 tconn = session_lookup_connection_wt6 (fib_index,
2236 TRANSPORT_PROTO_TCP,
2237 thread_index, &is_filtered);
2238 tc = tcp_get_connection_from_transport (tconn);
2239 ASSERT (tcp_lookup_is_valid (tc, tcp));
2245 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2246 vlib_frame_t * from_frame, int is_ip4)
2248 tcp_main_t *tm = vnet_get_tcp_main ();
2249 u32 n_left_from, next_index, *from, *to_next;
2250 u32 my_thread_index = vm->thread_index, errors = 0;
2252 from = vlib_frame_vector_args (from_frame);
2253 n_left_from = from_frame->n_vectors;
2255 next_index = node->cached_next_index;
2257 while (n_left_from > 0)
2261 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2263 while (n_left_from > 0 && n_left_to_next > 0)
2265 u32 bi0, ack0, seq0;
2268 tcp_header_t *tcp0 = 0;
2269 tcp_connection_t *tc0;
2270 tcp_connection_t *new_tc0;
2271 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ENQUEUED;
2278 n_left_to_next -= 1;
2280 b0 = vlib_get_buffer (vm, bi0);
2282 tcp_half_open_connection_get (vnet_buffer (b0)->
2283 tcp.connection_index);
2284 if (PREDICT_FALSE (tc0 == 0))
2286 error0 = TCP_ERROR_INVALID_CONNECTION;
2290 /* Half-open completed recently but the connection was't removed
2291 * yet by the owning thread */
2292 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2294 /* Make sure the connection actually exists */
2295 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2296 my_thread_index, is_ip4));
2300 ack0 = vnet_buffer (b0)->tcp.ack_number;
2301 seq0 = vnet_buffer (b0)->tcp.seq_number;
2302 tcp0 = tcp_buffer_hdr (b0);
2304 /* Crude check to see if the connection handle does not match
2305 * the packet. Probably connection just switched to established */
2306 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2307 || tcp0->src_port != tc0->c_rmt_port))
2311 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
2314 /* SYNs, FINs and data consume sequence numbers */
2315 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
2316 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
2319 * 1. check the ACK bit
2323 * If the ACK bit is set
2324 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2325 * the RST bit is set, if so drop the segment and return)
2326 * <SEQ=SEG.ACK><CTL=RST>
2327 * and discard the segment. Return.
2328 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2332 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2334 clib_warning ("ack not in rcv wnd");
2335 if (!tcp_rst (tcp0))
2336 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2340 /* Make sure ACK is valid */
2341 if (seq_gt (tc0->snd_una, ack0))
2343 clib_warning ("ack invalid");
2349 * 2. check the RST bit
2354 /* If ACK is acceptable, signal client that peer is not
2355 * willing to accept connection and drop connection*/
2357 tcp_connection_reset (tc0);
2362 * 3. check the security and precedence (skipped)
2366 * 4. check the SYN bit
2369 /* No SYN flag. Drop. */
2370 if (!tcp_syn (tcp0))
2372 clib_warning ("not synack");
2377 if (tcp_options_parse (tcp0, &tc0->rcv_opts))
2379 clib_warning ("options parse fail");
2383 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2384 * current thread pool. */
2385 pool_get (tm->connections[my_thread_index], new_tc0);
2386 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
2387 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2388 new_tc0->c_thread_index = my_thread_index;
2389 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2390 new_tc0->irs = seq0;
2391 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
2392 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] =
2393 TCP_TIMER_HANDLE_INVALID;
2394 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2396 /* If this is not the owning thread, wait for syn retransmit to
2397 * expire and cleanup then */
2398 if (tcp_half_open_connection_cleanup (tc0))
2399 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2401 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2403 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2404 new_tc0->tsval_recent_age = tcp_time_now ();
2407 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2408 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2410 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2411 << new_tc0->snd_wscale;
2412 new_tc0->snd_wl1 = seq0;
2413 new_tc0->snd_wl2 = ack0;
2415 tcp_connection_init_vars (new_tc0);
2417 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2418 if (PREDICT_TRUE (tcp_ack (tcp0)))
2420 /* Our SYN is ACKed: we have iss < ack = snd_una */
2422 /* TODO Dequeue acknowledged segments if we support Fast Open */
2423 new_tc0->snd_una = ack0;
2424 new_tc0->state = TCP_STATE_ESTABLISHED;
2426 /* Make sure las is initialized for the wnd computation */
2427 new_tc0->rcv_las = new_tc0->rcv_nxt;
2429 /* Notify app that we have connection. If session layer can't
2430 * allocate session send reset */
2431 if (session_stream_connect_notify (&new_tc0->connection, 0))
2433 clib_warning ("connect notify fail");
2434 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2435 tcp_connection_cleanup (new_tc0);
2439 /* Make sure after data segment processing ACK is sent */
2440 new_tc0->flags |= TCP_CONN_SNDACK;
2442 /* Update rtt with the syn-ack sample */
2443 tcp_update_rtt (new_tc0, vnet_buffer (b0)->tcp.ack_number);
2444 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2446 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2449 new_tc0->state = TCP_STATE_SYN_RCVD;
2451 /* Notify app that we have connection */
2452 if (session_stream_connect_notify (&new_tc0->connection, 0))
2454 tcp_connection_cleanup (new_tc0);
2455 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2456 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2461 tcp_init_snd_vars (tc0);
2462 tcp_make_synack (new_tc0, b0);
2463 next0 = tcp_next_output (is_ip4);
2468 /* Read data, if any */
2469 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2471 clib_warning ("rcvd data in syn-sent");
2472 error0 = tcp_segment_rcv (new_tc0, b0, &next0);
2473 if (error0 == TCP_ERROR_ACK_OK)
2474 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2475 tcp_maybe_inc_counter (syn_sent, error0, 1);
2479 tcp_make_ack (new_tc0, b0);
2480 next0 = tcp_next_output (new_tc0->c_is_ip4);
2485 b0->error = error0 ? node->errors[error0] : 0;
2487 ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2489 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2490 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2491 clib_memcpy (&t0->tcp_connection, tc0,
2492 sizeof (t0->tcp_connection));
2495 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2496 n_left_to_next, bi0, next0);
2499 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2502 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2504 tcp_inc_counter (syn_sent, TCP_ERROR_EVENT_FIFO_FULL, errors);
2505 return from_frame->n_vectors;
2509 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2510 vlib_frame_t * from_frame)
2512 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2516 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2517 vlib_frame_t * from_frame)
2519 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2523 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2525 .function = tcp4_syn_sent,
2526 .name = "tcp4-syn-sent",
2527 /* Takes a vector of packets. */
2528 .vector_size = sizeof (u32),
2529 .n_errors = TCP_N_ERROR,
2530 .error_strings = tcp_error_strings,
2531 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2534 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2535 foreach_tcp_state_next
2538 .format_trace = format_tcp_rx_trace_short,
2542 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2545 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2547 .function = tcp6_syn_sent_rcv,
2548 .name = "tcp6-syn-sent",
2549 /* Takes a vector of packets. */
2550 .vector_size = sizeof (u32),
2551 .n_errors = TCP_N_ERROR,
2552 .error_strings = tcp_error_strings,
2553 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2556 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2557 foreach_tcp_state_next
2560 .format_trace = format_tcp_rx_trace_short,
2564 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2566 vlib_node_registration_t tcp4_rcv_process_node;
2567 vlib_node_registration_t tcp6_rcv_process_node;
2570 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2571 * as per RFC793 p. 64
2574 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2575 vlib_frame_t * from_frame, int is_ip4)
2577 u32 n_left_from, next_index, *from, *to_next, n_fins = 0;
2578 u32 my_thread_index = vm->thread_index, errors = 0;
2580 from = vlib_frame_vector_args (from_frame);
2581 n_left_from = from_frame->n_vectors;
2582 next_index = node->cached_next_index;
2584 while (n_left_from > 0)
2588 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2590 while (n_left_from > 0 && n_left_to_next > 0)
2594 tcp_header_t *tcp0 = 0;
2595 tcp_connection_t *tc0;
2596 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_NONE;
2604 n_left_to_next -= 1;
2606 b0 = vlib_get_buffer (vm, bi0);
2607 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2609 if (PREDICT_FALSE (tc0 == 0))
2611 error0 = TCP_ERROR_INVALID_CONNECTION;
2615 tcp0 = tcp_buffer_hdr (b0);
2616 is_fin0 = tcp_is_fin (tcp0);
2618 /* SYNs, FINs and data consume sequence numbers */
2619 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2620 + tcp_is_syn (tcp0) + is_fin0 + vnet_buffer (b0)->tcp.data_len;
2624 tcp_connection_t *tmp;
2625 tmp = tcp_lookup_connection (tc0->c_fib_index, b0,
2626 my_thread_index, is_ip4);
2627 if (tmp->state != tc0->state)
2629 clib_warning ("state changed");
2635 * Special treatment for CLOSED
2637 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2639 error0 = TCP_ERROR_CONNECTION_CLOSED;
2644 * For all other states (except LISTEN)
2647 /* 1-4: check SEQ, RST, SYN */
2648 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, tcp0,
2651 tcp_maybe_inc_counter (rcv_process, error0, 1);
2655 /* 5: check the ACK field */
2658 case TCP_STATE_SYN_RCVD:
2660 * If the segment acknowledgment is not acceptable, form a
2662 * <SEQ=SEG.ACK><CTL=RST>
2665 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2667 TCP_DBG ("connection not accepted");
2668 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2669 error0 = TCP_ERROR_ACK_INVALID;
2673 /* Update rtt and rto */
2674 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
2676 /* Switch state to ESTABLISHED */
2677 tc0->state = TCP_STATE_ESTABLISHED;
2678 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2680 /* Initialize session variables */
2681 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2682 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2683 << tc0->rcv_opts.wscale;
2684 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2685 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2687 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2688 tcp_retransmit_timer_reset (tc0);
2689 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2690 stream_session_accept_notify (&tc0->connection);
2691 error0 = TCP_ERROR_ACK_OK;
2693 case TCP_STATE_ESTABLISHED:
2694 /* We can get packets in established state here because they
2695 * were enqueued before state change */
2696 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2698 tcp_maybe_inc_counter (rcv_process, error0, 1);
2703 case TCP_STATE_FIN_WAIT_1:
2704 /* In addition to the processing for the ESTABLISHED state, if
2705 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2706 * continue processing in that state. */
2707 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2709 tcp_maybe_inc_counter (rcv_process, error0, 1);
2713 /* Still have to send the FIN */
2714 if (tc0->flags & TCP_CONN_FINPNDG)
2716 /* TX fifo finally drained */
2717 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2720 /* If FIN is ACKed */
2721 else if (tc0->snd_una == tc0->snd_una_max)
2723 tc0->state = TCP_STATE_FIN_WAIT_2;
2724 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2726 /* Stop all retransmit timers because we have nothing more
2727 * to send. Enable waitclose though because we're willing to
2728 * wait for peer's FIN but not indefinitely. */
2729 tcp_connection_timers_reset (tc0);
2730 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2733 case TCP_STATE_FIN_WAIT_2:
2734 /* In addition to the processing for the ESTABLISHED state, if
2735 * the retransmission queue is empty, the user's CLOSE can be
2736 * acknowledged ("ok") but do not delete the TCB. */
2737 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2739 tcp_maybe_inc_counter (rcv_process, error0, 1);
2743 case TCP_STATE_CLOSE_WAIT:
2744 /* Do the same processing as for the ESTABLISHED state. */
2745 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2747 tcp_maybe_inc_counter (rcv_process, error0, 1);
2750 if (tc0->flags & TCP_CONN_FINPNDG)
2752 /* TX fifo finally drained */
2753 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2756 tcp_connection_timers_reset (tc0);
2757 tc0->state = TCP_STATE_LAST_ACK;
2758 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2763 case TCP_STATE_CLOSING:
2764 /* In addition to the processing for the ESTABLISHED state, if
2765 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2766 * otherwise ignore the segment. */
2767 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2769 tcp_maybe_inc_counter (rcv_process, error0, 1);
2773 tc0->state = TCP_STATE_TIME_WAIT;
2774 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2775 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2779 case TCP_STATE_LAST_ACK:
2780 /* The only thing that [should] arrive in this state is an
2781 * acknowledgment of our FIN. If our FIN is now acknowledged,
2782 * delete the TCB, enter the CLOSED state, and return. */
2784 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2786 error0 = TCP_ERROR_ACK_INVALID;
2789 error0 = TCP_ERROR_ACK_OK;
2790 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2791 /* Apparently our ACK for the peer's FIN was lost */
2792 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2798 tc0->state = TCP_STATE_CLOSED;
2799 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2801 /* Don't free the connection from the data path since
2802 * we can't ensure that we have no packets already enqueued
2803 * to output. Rely instead on the waitclose timer */
2804 tcp_connection_timers_reset (tc0);
2805 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, 1);
2810 case TCP_STATE_TIME_WAIT:
2811 /* The only thing that can arrive in this state is a
2812 * retransmission of the remote FIN. Acknowledge it, and restart
2813 * the 2 MSL timeout. */
2815 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2817 tcp_maybe_inc_counter (rcv_process, error0, 1);
2821 tcp_make_ack (tc0, b0);
2822 next0 = tcp_next_output (is_ip4);
2823 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2831 /* 6: check the URG bit TODO */
2833 /* 7: process the segment text */
2836 case TCP_STATE_ESTABLISHED:
2837 case TCP_STATE_FIN_WAIT_1:
2838 case TCP_STATE_FIN_WAIT_2:
2839 if (vnet_buffer (b0)->tcp.data_len)
2841 error0 = tcp_segment_rcv (tc0, b0, &next0);
2842 tcp_maybe_inc_counter (rcv_process, error0, 1);
2847 case TCP_STATE_CLOSE_WAIT:
2848 case TCP_STATE_CLOSING:
2849 case TCP_STATE_LAST_ACK:
2850 case TCP_STATE_TIME_WAIT:
2851 /* This should not occur, since a FIN has been received from the
2852 * remote side. Ignore the segment text. */
2856 /* 8: check the FIN bit */
2862 case TCP_STATE_ESTABLISHED:
2863 case TCP_STATE_SYN_RCVD:
2864 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2865 tcp_connection_timers_reset (tc0);
2866 tcp_make_fin (tc0, b0);
2868 tc0->snd_una_max = tc0->snd_nxt;
2869 tcp_retransmit_timer_set (tc0);
2870 next0 = tcp_next_output (tc0->c_is_ip4);
2871 stream_session_disconnect_notify (&tc0->connection);
2872 tc0->state = TCP_STATE_CLOSE_WAIT;
2873 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2875 case TCP_STATE_CLOSE_WAIT:
2876 case TCP_STATE_CLOSING:
2877 case TCP_STATE_LAST_ACK:
2880 case TCP_STATE_FIN_WAIT_1:
2881 tc0->state = TCP_STATE_CLOSING;
2882 tcp_make_ack (tc0, b0);
2883 next0 = tcp_next_output (is_ip4);
2884 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2885 /* Wait for ACK but not forever */
2886 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2888 case TCP_STATE_FIN_WAIT_2:
2889 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2890 tc0->state = TCP_STATE_TIME_WAIT;
2891 tcp_connection_timers_reset (tc0);
2892 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2893 tcp_make_ack (tc0, b0);
2894 next0 = tcp_next_output (is_ip4);
2895 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2897 case TCP_STATE_TIME_WAIT:
2898 /* Remain in the TIME-WAIT state. Restart the time-wait
2901 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2904 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2908 b0->error = error0 ? node->errors[error0] : 0;
2910 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2912 tcp_rx_trace_t *t0 =
2913 vlib_add_trace (vm, node, b0, sizeof (*t0));
2914 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2917 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2918 n_left_to_next, bi0, next0);
2921 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2924 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2926 tcp_inc_counter (rcv_process, TCP_ERROR_EVENT_FIFO_FULL, errors);
2927 tcp_inc_counter (rcv_process, TCP_ERROR_FIN_RCVD, n_fins);
2928 return from_frame->n_vectors;
2932 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2933 vlib_frame_t * from_frame)
2935 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2939 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2940 vlib_frame_t * from_frame)
2942 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2946 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2948 .function = tcp4_rcv_process,
2949 .name = "tcp4-rcv-process",
2950 /* Takes a vector of packets. */
2951 .vector_size = sizeof (u32),
2952 .n_errors = TCP_N_ERROR,
2953 .error_strings = tcp_error_strings,
2954 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2957 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2958 foreach_tcp_state_next
2961 .format_trace = format_tcp_rx_trace_short,
2965 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2968 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2970 .function = tcp6_rcv_process,
2971 .name = "tcp6-rcv-process",
2972 /* Takes a vector of packets. */
2973 .vector_size = sizeof (u32),
2974 .n_errors = TCP_N_ERROR,
2975 .error_strings = tcp_error_strings,
2976 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2979 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2980 foreach_tcp_state_next
2983 .format_trace = format_tcp_rx_trace_short,
2987 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2989 vlib_node_registration_t tcp4_listen_node;
2990 vlib_node_registration_t tcp6_listen_node;
2993 * LISTEN state processing as per RFC 793 p. 65
2996 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2997 vlib_frame_t * from_frame, int is_ip4)
2999 u32 n_left_from, next_index, *from, *to_next, n_syns = 0;
3000 u32 my_thread_index = vm->thread_index;
3002 from = vlib_frame_vector_args (from_frame);
3003 n_left_from = from_frame->n_vectors;
3005 next_index = node->cached_next_index;
3007 while (n_left_from > 0)
3011 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
3013 while (n_left_from > 0 && n_left_to_next > 0)
3018 tcp_header_t *th0 = 0;
3019 tcp_connection_t *lc0;
3022 tcp_connection_t *child0;
3023 u32 error0 = TCP_ERROR_NONE, next0 = tcp_next_drop (is_ip4);
3030 n_left_to_next -= 1;
3032 b0 = vlib_get_buffer (vm, bi0);
3033 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3037 ip40 = vlib_buffer_get_current (b0);
3038 th0 = ip4_next_header (ip40);
3042 ip60 = vlib_buffer_get_current (b0);
3043 th0 = ip6_next_header (ip60);
3046 /* Create child session. For syn-flood protection use filter */
3048 /* 1. first check for an RST: handled in dispatch */
3049 /* if (tcp_rst (th0))
3052 /* 2. second check for an ACK: handled in dispatch */
3053 /* if (tcp_ack (th0))
3055 tcp_send_reset (b0, is_ip4);
3059 /* 3. check for a SYN (did that already) */
3061 /* Make sure connection wasn't just created */
3062 child0 = tcp_lookup_connection (lc0->c_fib_index, b0,
3063 my_thread_index, is_ip4);
3064 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3066 error0 = TCP_ERROR_CREATE_EXISTS;
3070 /* Create child session and send SYN-ACK */
3071 child0 = tcp_connection_new (my_thread_index);
3072 child0->c_lcl_port = th0->dst_port;
3073 child0->c_rmt_port = th0->src_port;
3074 child0->c_is_ip4 = is_ip4;
3075 child0->state = TCP_STATE_SYN_RCVD;
3076 child0->c_fib_index = lc0->c_fib_index;
3080 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3081 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3085 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
3086 sizeof (ip6_address_t));
3087 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
3088 sizeof (ip6_address_t));
3091 if (tcp_options_parse (th0, &child0->rcv_opts))
3093 clib_warning ("options parse fail");
3097 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3098 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3099 child0->rcv_las = child0->rcv_nxt;
3100 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3102 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3103 * segments are used to initialize PAWS. */
3104 if (tcp_opts_tstamp (&child0->rcv_opts))
3106 child0->tsval_recent = child0->rcv_opts.tsval;
3107 child0->tsval_recent_age = tcp_time_now ();
3110 if (tcp_opts_wscale (&child0->rcv_opts))
3111 child0->snd_wscale = child0->rcv_opts.wscale;
3113 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3114 << child0->snd_wscale;
3115 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3116 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3118 tcp_connection_init_vars (child0);
3119 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
3121 if (stream_session_accept (&child0->connection, lc0->c_s_index,
3124 clib_warning ("session accept fail");
3125 tcp_connection_cleanup (child0);
3126 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3130 /* Reuse buffer to make syn-ack and send */
3131 tcp_make_synack (child0, b0);
3132 next0 = tcp_next_output (is_ip4);
3133 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
3136 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3138 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3139 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3140 clib_memcpy (&t0->tcp_connection, lc0,
3141 sizeof (t0->tcp_connection));
3144 n_syns += (error0 == TCP_ERROR_NONE);
3145 b0->error = node->errors[error0];
3147 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
3148 n_left_to_next, bi0, next0);
3151 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
3154 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3155 return from_frame->n_vectors;
3159 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3160 vlib_frame_t * from_frame)
3162 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3166 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3167 vlib_frame_t * from_frame)
3169 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3173 VLIB_REGISTER_NODE (tcp4_listen_node) =
3175 .function = tcp4_listen,
3176 .name = "tcp4-listen",
3177 /* Takes a vector of packets. */
3178 .vector_size = sizeof (u32),
3179 .n_errors = TCP_N_ERROR,
3180 .error_strings = tcp_error_strings,
3181 .n_next_nodes = TCP_LISTEN_N_NEXT,
3184 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3185 foreach_tcp_state_next
3188 .format_trace = format_tcp_rx_trace_short,
3192 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
3195 VLIB_REGISTER_NODE (tcp6_listen_node) =
3197 .function = tcp6_listen,
3198 .name = "tcp6-listen",
3199 /* Takes a vector of packets. */
3200 .vector_size = sizeof (u32),
3201 .n_errors = TCP_N_ERROR,
3202 .error_strings = tcp_error_strings,
3203 .n_next_nodes = TCP_LISTEN_N_NEXT,
3206 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3207 foreach_tcp_state_next
3210 .format_trace = format_tcp_rx_trace_short,
3214 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
3216 vlib_node_registration_t tcp4_input_node;
3217 vlib_node_registration_t tcp6_input_node;
3219 typedef enum _tcp_input_next
3221 TCP_INPUT_NEXT_DROP,
3222 TCP_INPUT_NEXT_LISTEN,
3223 TCP_INPUT_NEXT_RCV_PROCESS,
3224 TCP_INPUT_NEXT_SYN_SENT,
3225 TCP_INPUT_NEXT_ESTABLISHED,
3226 TCP_INPUT_NEXT_RESET,
3227 TCP_INPUT_NEXT_PUNT,
3231 #define foreach_tcp4_input_next \
3232 _ (DROP, "ip4-drop") \
3233 _ (LISTEN, "tcp4-listen") \
3234 _ (RCV_PROCESS, "tcp4-rcv-process") \
3235 _ (SYN_SENT, "tcp4-syn-sent") \
3236 _ (ESTABLISHED, "tcp4-established") \
3237 _ (RESET, "tcp4-reset") \
3238 _ (PUNT, "ip4-punt")
3240 #define foreach_tcp6_input_next \
3241 _ (DROP, "ip6-drop") \
3242 _ (LISTEN, "tcp6-listen") \
3243 _ (RCV_PROCESS, "tcp6-rcv-process") \
3244 _ (SYN_SENT, "tcp6-syn-sent") \
3245 _ (ESTABLISHED, "tcp6-established") \
3246 _ (RESET, "tcp6-reset") \
3247 _ (PUNT, "ip6-punt")
3249 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3252 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3253 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3255 tcp_connection_t *tc;
3260 for (i = 0; i < n_bufs; i++)
3262 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3264 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3265 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3267 tcp = vlib_buffer_get_current (bs[i]);
3268 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3274 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3276 if (*error == TCP_ERROR_FILTERED)
3278 *next = TCP_INPUT_NEXT_DROP;
3280 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3282 *next = TCP_INPUT_NEXT_PUNT;
3283 *error = TCP_ERROR_PUNT;
3287 *next = TCP_INPUT_NEXT_RESET;
3288 *error = TCP_ERROR_NO_LISTENER;
3292 static inline tcp_connection_t *
3293 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3296 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3297 int n_advance_bytes, n_data_bytes;
3298 transport_connection_t *tc;
3304 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3305 tcp = ip4_next_header (ip4);
3306 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3307 n_advance_bytes = (ip4_header_bytes (ip4) + tcp_header_bytes (tcp));
3308 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3310 /* Length check. Checksum computed by ipx_local no need to compute again */
3311 if (PREDICT_FALSE (n_advance_bytes < 0))
3313 *error = TCP_ERROR_LENGTH;
3317 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3318 &ip4->src_address, tcp->dst_port,
3319 tcp->src_port, TRANSPORT_PROTO_TCP,
3320 thread_index, &is_filtered);
3324 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3325 tcp = ip6_next_header (ip6);
3326 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3327 n_advance_bytes = tcp_header_bytes (tcp);
3328 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3330 n_advance_bytes += sizeof (ip6[0]);
3332 if (PREDICT_FALSE (n_advance_bytes < 0))
3334 *error = TCP_ERROR_LENGTH;
3338 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3339 &ip6->src_address, tcp->dst_port,
3340 tcp->src_port, TRANSPORT_PROTO_TCP,
3341 thread_index, &is_filtered);
3344 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3345 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3346 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3347 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3348 vnet_buffer (b)->tcp.flags = 0;
3350 *error = is_filtered ? TCP_ERROR_FILTERED : *error;
3352 return tcp_get_connection_from_transport (tc);
3356 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3357 vlib_buffer_t * b, u16 * next, u32 * error)
3362 tcp = tcp_buffer_hdr (b);
3363 flags = tcp->flags & filter_flags;
3364 *next = tm->dispatch_table[tc->state][flags].next;
3365 *error = tm->dispatch_table[tc->state][flags].error;
3367 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3368 || *next == TCP_INPUT_NEXT_RESET))
3370 /* Overload tcp flags to store state */
3371 tcp_state_t state = tc->state;
3372 vnet_buffer (b)->tcp.flags = tc->state;
3374 if (*error == TCP_ERROR_DISPATCH)
3375 clib_warning ("disp error state %U flags %U", format_tcp_state,
3376 state, format_tcp_flags, (int) flags);
3381 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3382 vlib_frame_t * frame, int is_ip4)
3384 u32 n_left_from, *from, thread_index = vm->thread_index;
3385 tcp_main_t *tm = vnet_get_tcp_main ();
3386 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3387 u16 nexts[VLIB_FRAME_SIZE], *next;
3389 tcp_set_time_now (thread_index);
3391 from = vlib_frame_vector_args (frame);
3392 n_left_from = frame->n_vectors;
3393 vlib_get_buffers (vm, from, bufs, n_left_from);
3398 while (n_left_from >= 4)
3400 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3401 tcp_connection_t *tc0, *tc1;
3404 vlib_prefetch_buffer_header (b[2], STORE);
3405 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3407 vlib_prefetch_buffer_header (b[3], STORE);
3408 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3411 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3413 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3414 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4);
3416 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3418 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3419 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3421 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3422 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3424 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3425 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3429 if (PREDICT_TRUE (tc0 != 0))
3431 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3432 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3433 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3436 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3438 if (PREDICT_TRUE (tc1 != 0))
3440 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3441 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3442 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3445 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3452 while (n_left_from > 0)
3454 tcp_connection_t *tc0;
3455 u32 error0 = TCP_ERROR_NO_LISTENER;
3457 if (n_left_from > 1)
3459 vlib_prefetch_buffer_header (b[1], STORE);
3460 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3463 next[0] = TCP_INPUT_NEXT_DROP;
3464 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3465 if (PREDICT_TRUE (tc0 != 0))
3467 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3468 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3469 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3472 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3479 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3480 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3482 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3483 return frame->n_vectors;
3487 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3488 vlib_frame_t * from_frame)
3490 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3494 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3495 vlib_frame_t * from_frame)
3497 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3501 VLIB_REGISTER_NODE (tcp4_input_node) =
3503 .function = tcp4_input,
3504 .name = "tcp4-input",
3505 /* Takes a vector of packets. */
3506 .vector_size = sizeof (u32),
3507 .n_errors = TCP_N_ERROR,
3508 .error_strings = tcp_error_strings,
3509 .n_next_nodes = TCP_INPUT_N_NEXT,
3512 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3513 foreach_tcp4_input_next
3516 .format_buffer = format_tcp_header,
3517 .format_trace = format_tcp_rx_trace,
3521 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3524 VLIB_REGISTER_NODE (tcp6_input_node) =
3526 .function = tcp6_input,
3527 .name = "tcp6-input",
3528 /* Takes a vector of packets. */
3529 .vector_size = sizeof (u32),
3530 .n_errors = TCP_N_ERROR,
3531 .error_strings = tcp_error_strings,
3532 .n_next_nodes = TCP_INPUT_N_NEXT,
3535 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3536 foreach_tcp6_input_next
3539 .format_buffer = format_tcp_header,
3540 .format_trace = format_tcp_rx_trace,
3544 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3547 tcp_dispatch_table_init (tcp_main_t * tm)
3550 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3551 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3553 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3554 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3557 #define _(t,f,n,e) \
3559 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3560 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3563 /* SYNs for new connections -> tcp-listen. */
3564 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3565 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3566 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_RST_RCVD);
3567 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3569 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3570 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3571 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3572 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3574 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3575 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3577 /* SYN-ACK for a SYN */
3578 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3580 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3581 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3582 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3584 /* ACK for for established connection -> tcp-established. */
3585 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3586 /* FIN for for established connection -> tcp-established. */
3587 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3588 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3590 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3591 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3593 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3594 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3596 /* ACK or FIN-ACK to our FIN */
3597 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3598 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3600 /* FIN in reply to our FIN from the other side */
3601 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3602 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3603 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3604 /* FIN confirming that the peer (app) has closed */
3605 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3606 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3607 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3609 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3610 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3612 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3613 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3614 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3616 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3617 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3618 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3619 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3621 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3622 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3623 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3624 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3625 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3626 TCP_ERROR_CONNECTION_CLOSED);
3630 static clib_error_t *
3631 tcp_input_init (vlib_main_t * vm)
3633 clib_error_t *error = 0;
3634 tcp_main_t *tm = vnet_get_tcp_main ();
3636 if ((error = vlib_call_init_function (vm, tcp_init)))
3639 /* Initialize dispatch table. */
3640 tcp_dispatch_table_init (tm);
3645 VLIB_INIT_FUNCTION (tcp_input_init);
3648 * fd.io coding-style-patch-verification: ON
3651 * eval: (c-set-style "gnu")