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_w_thread (tc->c_thread_index);
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,
311 tcp_time_now_w_thread (tc0->c_thread_index)))
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 u32 now = tcp_time_now_w_thread (tc->c_thread_index);
474 mrtt = clib_max (now - tc->rcv_opts.tsecr, 1);
477 /* Ignore dubious measurements */
478 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
481 tcp_estimate_rtt (tc, mrtt);
485 /* Allow measuring of a new RTT */
488 /* If we got here something must've been ACKed so make sure boff is 0,
489 * even if mrtt is not valid since we update the rto lower */
497 * Dequeue bytes that have been acked and while at it update RTT estimates.
500 tcp_dequeue_acked (tcp_connection_t * tc, u32 ack)
502 /* Dequeue the newly ACKed add SACKed bytes */
503 stream_session_dequeue_drop (&tc->connection,
504 tc->bytes_acked + tc->sack_sb.snd_una_adv);
506 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
508 /* Update rtt and rto */
509 tcp_update_rtt (tc, ack);
511 /* If everything has been acked, stop retransmit timer
512 * otherwise update. */
513 tcp_retransmit_timer_update (tc);
517 * Check if duplicate ack as per RFC5681 Sec. 2
520 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
523 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
524 && seq_gt (tc->snd_una_max, tc->snd_una)
525 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
526 && (prev_snd_wnd == tc->snd_wnd));
530 * Checks if ack is a congestion control event.
533 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
534 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
536 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
537 * defined to be 'duplicate' */
538 *is_dack = tc->sack_sb.last_sacked_bytes
539 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
541 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
545 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
547 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
548 return hole - sb->holes;
552 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
554 return hole->end - hole->start;
557 sack_scoreboard_hole_t *
558 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
560 if (index != TCP_INVALID_SACK_HOLE_INDEX)
561 return pool_elt_at_index (sb->holes, index);
565 sack_scoreboard_hole_t *
566 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
568 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
569 return pool_elt_at_index (sb->holes, hole->next);
573 sack_scoreboard_hole_t *
574 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
576 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
577 return pool_elt_at_index (sb->holes, hole->prev);
581 sack_scoreboard_hole_t *
582 scoreboard_first_hole (sack_scoreboard_t * sb)
584 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
585 return pool_elt_at_index (sb->holes, sb->head);
589 sack_scoreboard_hole_t *
590 scoreboard_last_hole (sack_scoreboard_t * sb)
592 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
593 return pool_elt_at_index (sb->holes, sb->tail);
598 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
600 sack_scoreboard_hole_t *next, *prev;
602 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
604 next = pool_elt_at_index (sb->holes, hole->next);
605 next->prev = hole->prev;
609 sb->tail = hole->prev;
612 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
614 prev = pool_elt_at_index (sb->holes, hole->prev);
615 prev->next = hole->next;
619 sb->head = hole->next;
622 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
623 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
625 /* Poison the entry */
627 clib_memset (hole, 0xfe, sizeof (*hole));
629 pool_put (sb->holes, hole);
632 static sack_scoreboard_hole_t *
633 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
636 sack_scoreboard_hole_t *hole, *next, *prev;
639 pool_get (sb->holes, hole);
640 clib_memset (hole, 0, sizeof (*hole));
644 hole_index = scoreboard_hole_index (sb, hole);
646 prev = scoreboard_get_hole (sb, prev_index);
649 hole->prev = prev_index;
650 hole->next = prev->next;
652 if ((next = scoreboard_next_hole (sb, hole)))
653 next->prev = hole_index;
655 sb->tail = hole_index;
657 prev->next = hole_index;
661 sb->head = hole_index;
662 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
663 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
670 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
672 sack_scoreboard_hole_t *left, *right;
673 u32 bytes = 0, blks = 0;
676 sb->sacked_bytes = 0;
677 left = scoreboard_last_hole (sb);
681 if (seq_gt (sb->high_sacked, left->end))
683 bytes = sb->high_sacked - left->end;
687 while ((right = left)
688 && bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
689 && blks < TCP_DUPACK_THRESHOLD
690 /* left not updated if above conditions fail */
691 && (left = scoreboard_prev_hole (sb, right)))
693 bytes += right->start - left->end;
697 /* left is first lost */
702 sb->lost_bytes += scoreboard_hole_bytes (right);
704 left = scoreboard_prev_hole (sb, right);
706 bytes += right->start - left->end;
708 while ((right = left));
711 sb->sacked_bytes = bytes;
715 * Figure out the next hole to retransmit
717 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
719 sack_scoreboard_hole_t *
720 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
721 sack_scoreboard_hole_t * start,
722 u8 have_unsent, 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): available unsent data */
747 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 snd_una)
776 sack_scoreboard_hole_t *hole;
777 hole = scoreboard_first_hole (sb);
780 snd_una = seq_gt (snd_una, hole->start) ? snd_una : hole->start;
781 sb->cur_rxt_hole = sb->head;
783 sb->high_rxt = snd_una;
784 sb->rescue_rxt = snd_una - 1;
788 scoreboard_init (sack_scoreboard_t * sb)
790 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
791 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
792 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
796 scoreboard_clear (sack_scoreboard_t * sb)
798 sack_scoreboard_hole_t *hole;
799 while ((hole = scoreboard_first_hole (sb)))
801 scoreboard_remove_hole (sb, hole);
803 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
804 ASSERT (pool_elts (sb->holes) == 0);
805 sb->sacked_bytes = 0;
806 sb->last_sacked_bytes = 0;
807 sb->last_bytes_delivered = 0;
812 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
816 * Test that scoreboard is sane after recovery
818 * Returns 1 if scoreboard is empty or if first hole beyond
822 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
824 sack_scoreboard_hole_t *hole;
825 hole = scoreboard_first_hole (&tc->sack_sb);
826 return (!hole || (seq_geq (hole->start, tc->snd_una)
827 && seq_lt (hole->end, tc->snd_una_max)));
831 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
833 sack_scoreboard_t *sb = &tc->sack_sb;
834 sack_block_t *blk, tmp;
835 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
836 u32 blk_index = 0, old_sacked_bytes, hole_index;
839 sb->last_sacked_bytes = 0;
840 sb->last_bytes_delivered = 0;
843 if (!tcp_opts_sack (&tc->rcv_opts)
844 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
847 old_sacked_bytes = sb->sacked_bytes;
849 /* Remove invalid blocks */
850 blk = tc->rcv_opts.sacks;
851 while (blk < vec_end (tc->rcv_opts.sacks))
853 if (seq_lt (blk->start, blk->end)
854 && seq_gt (blk->start, tc->snd_una)
855 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_una_max))
860 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
863 /* Add block for cumulative ack */
864 if (seq_gt (ack, tc->snd_una))
866 tmp.start = tc->snd_una;
868 vec_add1 (tc->rcv_opts.sacks, tmp);
871 if (vec_len (tc->rcv_opts.sacks) == 0)
874 tcp_scoreboard_trace_add (tc, ack);
876 /* Make sure blocks are ordered */
877 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
878 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
879 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
881 tmp = tc->rcv_opts.sacks[i];
882 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
883 tc->rcv_opts.sacks[j] = tmp;
886 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
888 /* If no holes, insert the first that covers all outstanding bytes */
889 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
890 tc->snd_una, tc->snd_una_max);
891 sb->tail = scoreboard_hole_index (sb, last_hole);
892 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
893 sb->high_sacked = tmp.end;
897 /* If we have holes but snd_una_max is beyond the last hole, update
899 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
900 last_hole = scoreboard_last_hole (sb);
901 if (seq_gt (tc->snd_una_max, last_hole->end))
903 if (seq_geq (last_hole->start, sb->high_sacked))
905 last_hole->end = tc->snd_una_max;
907 /* New hole after high sacked block */
908 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
910 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
914 /* Keep track of max byte sacked for when the last hole
916 if (seq_gt (tmp.end, sb->high_sacked))
917 sb->high_sacked = tmp.end;
920 /* Walk the holes with the SACK blocks */
921 hole = pool_elt_at_index (sb->holes, sb->head);
922 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
924 blk = &tc->rcv_opts.sacks[blk_index];
925 if (seq_leq (blk->start, hole->start))
927 /* Block covers hole. Remove hole */
928 if (seq_geq (blk->end, hole->end))
930 next_hole = scoreboard_next_hole (sb, hole);
932 /* Byte accounting: snd_una needs to be advanced */
937 if (seq_lt (ack, next_hole->start))
938 sb->snd_una_adv = next_hole->start - ack;
939 sb->last_bytes_delivered +=
940 next_hole->start - hole->end;
944 ASSERT (seq_geq (sb->high_sacked, ack));
945 sb->snd_una_adv = sb->high_sacked - ack;
946 sb->last_bytes_delivered += sb->high_sacked - hole->end;
950 scoreboard_remove_hole (sb, hole);
953 /* Partial 'head' overlap */
956 if (seq_gt (blk->end, hole->start))
958 hole->start = blk->end;
965 /* Hole must be split */
966 if (seq_lt (blk->end, hole->end))
968 hole_index = scoreboard_hole_index (sb, hole);
969 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
972 /* Pool might've moved */
973 hole = scoreboard_get_hole (sb, hole_index);
974 hole->end = blk->start;
976 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
978 else if (seq_lt (blk->start, hole->end))
980 hole->end = blk->start;
982 hole = scoreboard_next_hole (sb, hole);
986 if (pool_elts (sb->holes) == 1)
988 hole = scoreboard_first_hole (sb);
989 if (hole->start == ack + sb->snd_una_adv
990 && hole->end == tc->snd_una_max)
991 scoreboard_remove_hole (sb, hole);
994 scoreboard_update_bytes (tc, sb);
995 sb->last_sacked_bytes = sb->sacked_bytes
996 - (old_sacked_bytes - sb->last_bytes_delivered);
997 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
998 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
999 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
1000 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
1001 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1002 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1003 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
1004 TCP_EVT_DBG (TCP_EVT_CC_SCOREBOARD, tc);
1008 * Try to update snd_wnd based on feedback received from peer.
1010 * If successful, and new window is 'effectively' 0, activate persist
1014 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1016 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1017 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1018 if (seq_lt (tc->snd_wl1, seq)
1019 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1021 tc->snd_wnd = snd_wnd;
1024 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
1026 if (tc->snd_wnd < tc->snd_mss)
1028 /* Set persist timer if not set and we just got 0 wnd */
1029 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1030 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1031 tcp_persist_timer_set (tc);
1035 tcp_persist_timer_reset (tc);
1036 if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
1039 tcp_update_rto (tc);
1046 * Init loss recovery/fast recovery.
1048 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1049 * updated in @ref tcp_cc_handle_event after fast retransmit
1052 tcp_cc_init_congestion (tcp_connection_t * tc)
1054 tcp_fastrecovery_on (tc);
1055 tc->snd_congestion = tc->snd_una_max;
1056 tc->cwnd_acc_bytes = 0;
1057 tc->snd_rxt_bytes = 0;
1058 tc->prev_ssthresh = tc->ssthresh;
1059 tc->prev_cwnd = tc->cwnd;
1060 tc->cc_algo->congestion (tc);
1061 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
1065 tcp_cc_recovery_exit (tcp_connection_t * tc)
1068 tcp_update_rto (tc);
1070 tc->snd_nxt = tc->snd_una_max;
1071 tcp_recovery_off (tc);
1072 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1076 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
1078 tc->cc_algo->recovered (tc);
1079 tc->snd_rxt_bytes = 0;
1080 tc->rcv_dupacks = 0;
1081 tc->snd_nxt = tc->snd_una_max;
1082 tc->snd_rxt_bytes = 0;
1084 tcp_fastrecovery_off (tc);
1085 tcp_fastrecovery_1_smss_off (tc);
1086 tcp_fastrecovery_first_off (tc);
1088 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1092 tcp_cc_congestion_undo (tcp_connection_t * tc)
1094 tc->cwnd = tc->prev_cwnd;
1095 tc->ssthresh = tc->prev_ssthresh;
1096 tc->snd_nxt = tc->snd_una_max;
1097 tc->rcv_dupacks = 0;
1098 if (tcp_in_recovery (tc))
1099 tcp_cc_recovery_exit (tc);
1100 else if (tcp_in_fastrecovery (tc))
1101 tcp_cc_fastrecovery_exit (tc);
1102 ASSERT (tc->rto_boff == 0);
1103 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
1107 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1109 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1111 && tcp_opts_tstamp (&tc->rcv_opts)
1112 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1116 tcp_cc_is_spurious_fast_rxt (tcp_connection_t * tc)
1118 return (tcp_in_fastrecovery (tc)
1119 && tc->cwnd > tc->ssthresh + 3 * tc->snd_mss);
1123 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1125 return (tcp_cc_is_spurious_timeout_rxt (tc)
1126 || tcp_cc_is_spurious_fast_rxt (tc));
1130 tcp_cc_recover (tcp_connection_t * tc)
1132 ASSERT (tcp_in_cong_recovery (tc));
1133 if (tcp_cc_is_spurious_retransmit (tc))
1135 tcp_cc_congestion_undo (tc);
1139 if (tcp_in_recovery (tc))
1140 tcp_cc_recovery_exit (tc);
1141 else if (tcp_in_fastrecovery (tc))
1142 tcp_cc_fastrecovery_exit (tc);
1144 ASSERT (tc->rto_boff == 0);
1145 ASSERT (!tcp_in_cong_recovery (tc));
1146 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1151 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
1153 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1155 /* Congestion avoidance */
1156 tcp_cc_rcv_ack (tc);
1158 /* If a cumulative ack, make sure dupacks is 0 */
1159 tc->rcv_dupacks = 0;
1161 /* When dupacks hits the threshold we only enter fast retransmit if
1162 * cumulative ack covers more than snd_congestion. Should snd_una
1163 * wrap this test may fail under otherwise valid circumstances.
1164 * Therefore, proactively update snd_congestion when wrap detected. */
1166 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1167 && seq_gt (tc->snd_congestion, tc->snd_una)))
1168 tc->snd_congestion = tc->snd_una - 1;
1172 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1174 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1178 tcp_should_fastrecover (tcp_connection_t * tc)
1180 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1181 || tcp_should_fastrecover_sack (tc));
1185 tcp_program_fastretransmit (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1187 if (!(tc->flags & TCP_CONN_FRXT_PENDING))
1189 vec_add1 (wrk->pending_fast_rxt, tc->c_c_index);
1190 tc->flags |= TCP_CONN_FRXT_PENDING;
1195 tcp_do_fastretransmits (tcp_worker_ctx_t * wrk)
1197 u32 *ongoing_fast_rxt, burst_bytes, sent_bytes, thread_index;
1198 u32 max_burst_size, burst_size, n_segs = 0, n_segs_now;
1199 tcp_connection_t *tc;
1203 if (vec_len (wrk->pending_fast_rxt) == 0
1204 && vec_len (wrk->postponed_fast_rxt) == 0)
1207 thread_index = wrk->vm->thread_index;
1208 last_cpu_time = wrk->vm->clib_time.last_cpu_time;
1209 ongoing_fast_rxt = wrk->ongoing_fast_rxt;
1210 vec_append (ongoing_fast_rxt, wrk->postponed_fast_rxt);
1211 vec_append (ongoing_fast_rxt, wrk->pending_fast_rxt);
1213 _vec_len (wrk->postponed_fast_rxt) = 0;
1214 _vec_len (wrk->pending_fast_rxt) = 0;
1216 max_burst_size = VLIB_FRAME_SIZE / vec_len (ongoing_fast_rxt);
1217 max_burst_size = clib_max (max_burst_size, 1);
1219 for (i = 0; i < vec_len (ongoing_fast_rxt); i++)
1221 if (n_segs >= VLIB_FRAME_SIZE)
1223 vec_add1 (wrk->postponed_fast_rxt, ongoing_fast_rxt[i]);
1227 tc = tcp_connection_get (ongoing_fast_rxt[i], thread_index);
1228 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1230 if (!tcp_in_fastrecovery (tc))
1233 burst_size = clib_min (max_burst_size, VLIB_FRAME_SIZE - n_segs);
1234 burst_bytes = transport_connection_tx_pacer_burst (&tc->connection,
1236 burst_size = clib_min (burst_size, burst_bytes / tc->snd_mss);
1239 tcp_program_fastretransmit (wrk, tc);
1243 n_segs_now = tcp_fast_retransmit (wrk, tc, burst_size);
1244 sent_bytes = clib_min (n_segs_now * tc->snd_mss, burst_bytes);
1245 transport_connection_tx_pacer_update_bytes (&tc->connection,
1247 n_segs += n_segs_now;
1249 _vec_len (ongoing_fast_rxt) = 0;
1250 wrk->ongoing_fast_rxt = ongoing_fast_rxt;
1254 * One function to rule them all ... and in the darkness bind them
1257 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1261 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1263 if (tc->bytes_acked)
1265 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1269 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1270 * it account for the bytes that left the network.
1272 else if (is_dack && !tcp_in_recovery (tc))
1274 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1275 ASSERT (tc->snd_una != tc->snd_una_max
1276 || tc->sack_sb.last_sacked_bytes);
1280 /* Pure duplicate ack. If some data got acked, it's handled lower */
1281 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1283 ASSERT (tcp_in_fastrecovery (tc));
1284 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1287 else if (tcp_should_fastrecover (tc))
1291 ASSERT (!tcp_in_fastrecovery (tc));
1293 /* Heuristic to catch potential late dupacks
1294 * after fast retransmit exits */
1295 if (is_dack && tc->snd_una == tc->snd_congestion
1296 && timestamp_leq (tc->rcv_opts.tsecr, tc->tsecr_last_ack))
1298 tc->rcv_dupacks = 0;
1302 tcp_cc_init_congestion (tc);
1303 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1305 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1307 tc->cwnd = tc->ssthresh;
1308 scoreboard_init_high_rxt (&tc->sack_sb, tc->snd_una);
1312 /* Post retransmit update cwnd to ssthresh and account for the
1313 * three segments that have left the network and should've been
1314 * buffered at the receiver XXX */
1315 tc->cwnd = tc->ssthresh + 3 * tc->snd_mss;
1318 /* Constrain rate until we get a partial ack */
1319 pacer_wnd = clib_max (0.1 * tc->cwnd, 2 * tc->snd_mss);
1320 tcp_connection_tx_pacer_reset (tc, pacer_wnd,
1321 0 /* start bucket */ );
1322 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index),
1326 else if (!tc->bytes_acked
1327 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1329 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1335 /* Don't allow entry in fast recovery if still in recovery, for now */
1336 else if (0 && is_dack && tcp_in_recovery (tc))
1338 /* If of of the two conditions lower hold, reset dupacks because
1339 * we're probably after timeout (RFC6582 heuristics).
1340 * If Cumulative ack does not cover more than congestion threshold,
1342 * 1) The following doesn't hold: The congestion window is greater
1343 * than SMSS bytes and the difference between highest_ack
1344 * and prev_highest_ack is at most 4*SMSS bytes
1345 * 2) Echoed timestamp in the last non-dup ack does not equal the
1348 if (seq_leq (tc->snd_una, tc->snd_congestion)
1349 && ((!(tc->cwnd > tc->snd_mss
1350 && tc->bytes_acked <= 4 * tc->snd_mss))
1351 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1353 tc->rcv_dupacks = 0;
1358 if (!tc->bytes_acked)
1362 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1365 * Legitimate ACK. 1) See if we can exit recovery
1368 if (seq_geq (tc->snd_una, tc->snd_congestion))
1370 tcp_retransmit_timer_update (tc);
1372 /* If spurious return, we've already updated everything */
1373 if (tcp_cc_recover (tc))
1375 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1379 tc->snd_nxt = tc->snd_una_max;
1381 /* Treat as congestion avoidance ack */
1382 tcp_cc_rcv_ack (tc);
1387 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1390 /* Update the pacing rate. For the first partial ack we move from
1391 * the artificially constrained rate to the one after congestion */
1392 tcp_connection_tx_pacer_update (tc);
1394 /* XXX limit this only to first partial ack? */
1395 tcp_retransmit_timer_force_update (tc);
1397 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1398 * reset dupacks to 0. Also needed if in congestion recovery */
1399 tc->rcv_dupacks = 0;
1401 /* Post RTO timeout don't try anything fancy */
1402 if (tcp_in_recovery (tc))
1404 tcp_cc_rcv_ack (tc);
1405 transport_add_tx_event (&tc->connection);
1409 /* Remove retransmitted bytes that have been delivered */
1410 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1412 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1413 >= tc->sack_sb.last_bytes_delivered
1414 || (tc->flags & TCP_CONN_FINSNT));
1416 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1417 * remove sacked bytes delivered */
1418 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1420 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1421 - tc->sack_sb.last_bytes_delivered;
1422 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1423 tc->snd_rxt_bytes -= rxt_delivered;
1427 /* Apparently all retransmitted holes have been acked */
1428 tc->snd_rxt_bytes = 0;
1429 tc->sack_sb.high_rxt = tc->snd_una;
1434 tcp_fastrecovery_first_on (tc);
1435 /* Reuse last bytes delivered to track total bytes acked */
1436 tc->sack_sb.last_bytes_delivered += tc->bytes_acked;
1437 if (tc->snd_rxt_bytes > tc->bytes_acked)
1438 tc->snd_rxt_bytes -= tc->bytes_acked;
1440 tc->snd_rxt_bytes = 0;
1443 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1446 * Since this was a partial ack, try to retransmit some more data
1448 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1452 * Process incoming ACK
1455 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
1456 tcp_header_t * th, u32 * next, u32 * error)
1458 u32 prev_snd_wnd, prev_snd_una;
1461 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1463 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1464 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1466 /* When we entered recovery, we reset snd_nxt to snd_una. Seems peer
1467 * still has the data so accept the ack */
1468 if (tcp_in_recovery (tc)
1469 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_congestion))
1471 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1472 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
1473 tc->snd_una_max = tc->snd_nxt;
1477 /* If we have outstanding data and this is within the window, accept it,
1478 * probably retransmit has timed out. Otherwise ACK segment and then
1480 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1482 tcp_make_ack (tc, b);
1483 *next = tcp_next_output (tc->c_is_ip4);
1484 *error = TCP_ERROR_ACK_FUTURE;
1485 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1486 vnet_buffer (b)->tcp.ack_number);
1490 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1491 vnet_buffer (b)->tcp.ack_number);
1493 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1496 /* If old ACK, probably it's an old dupack */
1497 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1499 *error = TCP_ERROR_ACK_OLD;
1500 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1501 vnet_buffer (b)->tcp.ack_number);
1502 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1503 tcp_cc_handle_event (tc, 1);
1504 /* Don't drop yet */
1509 * Looks okay, process feedback
1512 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1513 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1515 prev_snd_wnd = tc->snd_wnd;
1516 prev_snd_una = tc->snd_una;
1517 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1518 vnet_buffer (b)->tcp.ack_number,
1519 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1520 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1521 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1522 tcp_validate_txf_size (tc, tc->bytes_acked);
1524 if (tc->bytes_acked)
1525 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
1527 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1530 * Check if we have congestion event
1533 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1535 tcp_cc_handle_event (tc, is_dack);
1536 if (!tcp_in_cong_recovery (tc))
1538 *error = TCP_ERROR_ACK_DUP;
1539 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1545 * Update congestion control (slow start/congestion avoidance)
1547 tcp_cc_update (tc, b);
1548 *error = TCP_ERROR_ACK_OK;
1553 tcp_sack_vector_is_sane (sack_block_t * sacks)
1556 for (i = 1; i < vec_len (sacks); i++)
1558 if (sacks[i - 1].end == sacks[i].start)
1565 * Build SACK list as per RFC2018.
1567 * Makes sure the first block contains the segment that generated the current
1568 * ACK and the following ones are the ones most recently reported in SACK
1571 * @param tc TCP connection for which the SACK list is updated
1572 * @param start Start sequence number of the newest SACK block
1573 * @param end End sequence of the newest SACK block
1576 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1578 sack_block_t *new_list = 0, *block = 0;
1581 /* If the first segment is ooo add it to the list. Last write might've moved
1582 * rcv_nxt over the first segment. */
1583 if (seq_lt (tc->rcv_nxt, start))
1585 vec_add2 (new_list, block, 1);
1586 block->start = start;
1590 /* Find the blocks still worth keeping. */
1591 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1593 /* Discard if rcv_nxt advanced beyond current block */
1594 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1597 /* Merge or drop if segment overlapped by the new segment */
1598 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1599 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1601 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1602 new_list[0].start = tc->snd_sacks[i].start;
1603 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1604 new_list[0].end = tc->snd_sacks[i].end;
1608 /* Save to new SACK list if we have space. */
1609 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1611 vec_add1 (new_list, tc->snd_sacks[i]);
1615 clib_warning ("sack discarded");
1619 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1621 /* Replace old vector with new one */
1622 vec_free (tc->snd_sacks);
1623 tc->snd_sacks = new_list;
1625 /* Segments should not 'touch' */
1626 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1630 tcp_sack_list_bytes (tcp_connection_t * tc)
1633 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1634 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1638 /** Enqueue data for delivery to application */
1640 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1643 int written, error = TCP_ERROR_ENQUEUED;
1645 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1647 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1648 1 /* queue event */ , 1);
1650 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1652 /* Update rcv_nxt */
1653 if (PREDICT_TRUE (written == data_len))
1655 tc->rcv_nxt += written;
1657 /* If more data written than expected, account for out-of-order bytes. */
1658 else if (written > data_len)
1660 tc->rcv_nxt += written;
1662 /* Send ACK confirming the update */
1663 tc->flags |= TCP_CONN_SNDACK;
1664 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1666 else if (written > 0)
1668 /* We've written something but FIFO is probably full now */
1669 tc->rcv_nxt += written;
1671 /* Depending on how fast the app is, all remaining buffers in burst will
1672 * not be enqueued. Inform peer */
1673 tc->flags |= TCP_CONN_SNDACK;
1675 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1679 tc->flags |= TCP_CONN_SNDACK;
1680 return TCP_ERROR_FIFO_FULL;
1683 /* Update SACK list if need be */
1684 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1686 /* Remove SACK blocks that have been delivered */
1687 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1693 /** Enqueue out-of-order data */
1695 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1698 stream_session_t *s0;
1701 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1704 /* Enqueue out-of-order data with relative offset */
1705 rv = session_enqueue_stream_connection (&tc->connection, b,
1706 vnet_buffer (b)->tcp.seq_number -
1707 tc->rcv_nxt, 0 /* queue event */ ,
1710 /* Nothing written */
1713 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1714 return TCP_ERROR_FIFO_FULL;
1717 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1719 /* Update SACK list if in use */
1720 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1722 ooo_segment_t *newest;
1725 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1727 /* Get the newest segment from the fifo */
1728 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1731 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1732 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1733 start = tc->rcv_nxt + offset;
1734 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1735 tcp_update_sack_list (tc, start, end);
1736 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1737 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1741 return TCP_ERROR_ENQUEUED_OOO;
1745 * Check if ACK could be delayed. If ack can be delayed, it should return
1746 * true for a full frame. If we're always acking return 0.
1749 tcp_can_delack (tcp_connection_t * tc)
1751 /* Send ack if ... */
1753 /* just sent a rcv wnd 0 */
1754 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1755 /* constrained to send ack */
1756 || (tc->flags & TCP_CONN_SNDACK) != 0
1757 /* we're almost out of tx wnd */
1758 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1765 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1767 u32 discard, first = b->current_length;
1768 vlib_main_t *vm = vlib_get_main ();
1770 /* Handle multi-buffer segments */
1771 if (n_bytes_to_drop > b->current_length)
1773 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1777 discard = clib_min (n_bytes_to_drop, b->current_length);
1778 vlib_buffer_advance (b, discard);
1779 b = vlib_get_buffer (vm, b->next_buffer);
1780 n_bytes_to_drop -= discard;
1782 while (n_bytes_to_drop);
1783 if (n_bytes_to_drop > first)
1784 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1787 vlib_buffer_advance (b, n_bytes_to_drop);
1788 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1793 * Receive buffer for connection and handle acks
1795 * It handles both in order or out-of-order data.
1798 tcp_segment_rcv (tcp_connection_t * tc, vlib_buffer_t * b, u32 * next0)
1800 u32 error, n_bytes_to_drop, n_data_bytes;
1802 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1803 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1804 ASSERT (n_data_bytes);
1806 /* Handle out-of-order data */
1807 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1809 /* Old sequence numbers allowed through because they overlapped
1811 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1813 /* Completely in the past (possible retransmit). Ack
1814 * retransmissions since we may not have any data to send */
1815 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1817 tcp_make_ack (tc, b);
1818 error = TCP_ERROR_SEGMENT_OLD;
1819 *next0 = tcp_next_output (tc->c_is_ip4);
1823 /* Chop off the bytes in the past and see if what is left
1824 * can be enqueued in order */
1825 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1826 n_data_bytes -= n_bytes_to_drop;
1827 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1828 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1830 error = TCP_ERROR_SEGMENT_OLD;
1831 *next0 = tcp_next_drop (tc->c_is_ip4);
1837 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1838 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1839 *next0 = tcp_next_output (tc->c_is_ip4);
1840 tcp_make_ack (tc, b);
1841 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1842 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1848 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1849 * segments can be enqueued after fifo tail offset changes. */
1850 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1851 if (tcp_can_delack (tc))
1853 *next0 = tcp_next_drop (tc->c_is_ip4);
1854 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1855 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1859 *next0 = tcp_next_output (tc->c_is_ip4);
1860 tcp_make_ack (tc, b);
1868 tcp_header_t tcp_header;
1869 tcp_connection_t tcp_connection;
1873 format_tcp_rx_trace (u8 * s, va_list * args)
1875 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1876 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1877 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1878 u32 indent = format_get_indent (s);
1880 s = format (s, "%U\n%U%U",
1881 format_tcp_header, &t->tcp_header, 128,
1882 format_white_space, indent,
1883 format_tcp_connection, &t->tcp_connection, 1);
1889 format_tcp_rx_trace_short (u8 * s, va_list * args)
1891 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1892 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1893 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1895 s = format (s, "%d -> %d (%U)",
1896 clib_net_to_host_u16 (t->tcp_header.dst_port),
1897 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
1898 t->tcp_connection.state);
1904 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1905 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1909 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1913 th0 = tcp_buffer_hdr (b0);
1915 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1919 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
1920 vlib_frame_t * frame, u8 is_ip4)
1924 n_left = frame->n_vectors;
1925 from = vlib_frame_vector_args (frame);
1929 tcp_connection_t *tc0;
1936 b0 = vlib_get_buffer (vm, bi0);
1938 if (b0->flags & VLIB_BUFFER_IS_TRACED)
1940 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1941 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1943 th0 = tcp_buffer_hdr (b0);
1944 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1953 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
1954 u8 is_ip4, u32 evt, u32 val)
1957 vlib_node_increment_counter (vm, tcp4_node, evt, val);
1959 vlib_node_increment_counter (vm, tcp6_node, evt, val);
1962 #define tcp_maybe_inc_counter(node_id, err, count) \
1964 if (next0 != tcp_next_drop (is_ip4)) \
1965 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1966 tcp6_##node_id##_node.index, is_ip4, err, \
1969 #define tcp_inc_counter(node_id, err, count) \
1970 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1971 tcp6_##node_id##_node.index, is_ip4, \
1973 #define tcp_maybe_inc_err_counter(cnts, err) \
1975 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
1977 #define tcp_inc_err_counter(cnts, err, val) \
1981 #define tcp_store_err_counters(node_id, cnts) \
1984 for (i = 0; i < TCP_N_ERROR; i++) \
1986 tcp_inc_counter(node_id, i, cnts[i]); \
1991 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1992 vlib_frame_t * frame, int is_ip4)
1994 u32 thread_index = vm->thread_index, errors = 0;
1995 u32 n_left_from, next_index, *from, *to_next;
1996 u16 err_counters[TCP_N_ERROR] = { 0 };
1999 if (node->flags & VLIB_NODE_FLAG_TRACE)
2000 tcp_established_trace_frame (vm, node, frame, is_ip4);
2002 from = vlib_frame_vector_args (frame);
2003 n_left_from = frame->n_vectors;
2004 next_index = node->cached_next_index;
2006 while (n_left_from > 0)
2010 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2011 while (n_left_from > 0 && n_left_to_next > 0)
2015 tcp_header_t *th0 = 0;
2016 tcp_connection_t *tc0;
2017 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ACK_OK;
2019 if (n_left_from > 1)
2022 pb = vlib_get_buffer (vm, from[1]);
2023 vlib_prefetch_buffer_header (pb, LOAD);
2024 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2032 n_left_to_next -= 1;
2034 b0 = vlib_get_buffer (vm, bi0);
2035 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2038 if (PREDICT_FALSE (tc0 == 0))
2040 error0 = TCP_ERROR_INVALID_CONNECTION;
2044 th0 = tcp_buffer_hdr (b0);
2045 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
2046 * dangling reference. */
2047 is_fin = tcp_is_fin (th0);
2049 /* SYNs, FINs and data consume sequence numbers */
2050 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2051 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
2053 /* TODO header prediction fast path */
2055 /* 1-4: check SEQ, RST, SYN */
2056 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0,
2059 tcp_maybe_inc_err_counter (err_counters, error0);
2060 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2064 /* 5: check the ACK field */
2065 if (PREDICT_FALSE (tcp_rcv_ack (tc0, b0, th0, &next0, &error0)))
2067 tcp_maybe_inc_err_counter (err_counters, error0);
2071 /* 6: check the URG bit TODO */
2073 /* 7: process the segment text */
2074 if (vnet_buffer (b0)->tcp.data_len)
2076 error0 = tcp_segment_rcv (tc0, b0, &next0);
2077 tcp_maybe_inc_err_counter (err_counters, error0);
2080 /* 8: check the FIN bit */
2081 if (PREDICT_FALSE (is_fin))
2083 /* Enter CLOSE-WAIT and notify session. To avoid lingering
2084 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
2085 /* Account for the FIN if nothing else was received */
2086 if (vnet_buffer (b0)->tcp.data_len == 0)
2088 tcp_make_ack (tc0, b0);
2089 next0 = tcp_next_output (tc0->c_is_ip4);
2090 tc0->state = TCP_STATE_CLOSE_WAIT;
2091 stream_session_disconnect_notify (&tc0->connection);
2092 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
2093 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2094 tcp_inc_err_counter (err_counters, TCP_ERROR_FIN_RCVD, 1);
2098 b0->error = node->errors[error0];
2099 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2100 n_left_to_next, bi0, next0);
2103 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2106 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2108 err_counters[TCP_ERROR_EVENT_FIFO_FULL] = errors;
2109 tcp_store_err_counters (established, err_counters);
2110 tcp_flush_frame_to_output (tcp_get_worker (thread_index), is_ip4);
2112 return frame->n_vectors;
2116 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2117 vlib_frame_t * from_frame)
2119 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2123 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2124 vlib_frame_t * from_frame)
2126 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2130 VLIB_REGISTER_NODE (tcp4_established_node) =
2132 .function = tcp4_established,
2133 .name = "tcp4-established",
2134 /* Takes a vector of packets. */
2135 .vector_size = sizeof (u32),
2136 .n_errors = TCP_N_ERROR,
2137 .error_strings = tcp_error_strings,
2138 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2141 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2142 foreach_tcp_state_next
2145 .format_trace = format_tcp_rx_trace_short,
2149 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
2152 VLIB_REGISTER_NODE (tcp6_established_node) =
2154 .function = tcp6_established,
2155 .name = "tcp6-established",
2156 /* Takes a vector of packets. */
2157 .vector_size = sizeof (u32),
2158 .n_errors = TCP_N_ERROR,
2159 .error_strings = tcp_error_strings,
2160 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2163 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2164 foreach_tcp_state_next
2167 .format_trace = format_tcp_rx_trace_short,
2172 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
2174 vlib_node_registration_t tcp4_syn_sent_node;
2175 vlib_node_registration_t tcp6_syn_sent_node;
2178 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2180 transport_connection_t *tmp = 0;
2187 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2190 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2191 && (tc->state == TCP_STATE_LISTEN
2192 || tc->c_rmt_port == hdr->src_port));
2196 handle = session_lookup_half_open_handle (&tc->connection);
2197 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2198 tc->c_proto, tc->c_is_ip4);
2202 if (tmp->lcl_port == hdr->dst_port
2203 && tmp->rmt_port == hdr->src_port)
2205 TCP_DBG ("half-open is valid!");
2213 * Lookup transport connection
2215 static tcp_connection_t *
2216 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2220 transport_connection_t *tconn;
2221 tcp_connection_t *tc;
2226 ip4 = vlib_buffer_get_current (b);
2227 tcp = ip4_next_header (ip4);
2228 tconn = session_lookup_connection_wt4 (fib_index,
2233 TRANSPORT_PROTO_TCP,
2234 thread_index, &is_filtered);
2235 tc = tcp_get_connection_from_transport (tconn);
2236 ASSERT (tcp_lookup_is_valid (tc, tcp));
2241 ip6 = vlib_buffer_get_current (b);
2242 tcp = ip6_next_header (ip6);
2243 tconn = session_lookup_connection_wt6 (fib_index,
2248 TRANSPORT_PROTO_TCP,
2249 thread_index, &is_filtered);
2250 tc = tcp_get_connection_from_transport (tconn);
2251 ASSERT (tcp_lookup_is_valid (tc, tcp));
2257 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2258 vlib_frame_t * from_frame, int is_ip4)
2260 tcp_main_t *tm = vnet_get_tcp_main ();
2261 u32 n_left_from, next_index, *from, *to_next;
2262 u32 my_thread_index = vm->thread_index, errors = 0;
2264 from = vlib_frame_vector_args (from_frame);
2265 n_left_from = from_frame->n_vectors;
2267 next_index = node->cached_next_index;
2269 while (n_left_from > 0)
2273 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2275 while (n_left_from > 0 && n_left_to_next > 0)
2277 u32 bi0, ack0, seq0;
2280 tcp_header_t *tcp0 = 0;
2281 tcp_connection_t *tc0;
2282 tcp_connection_t *new_tc0;
2283 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ENQUEUED;
2290 n_left_to_next -= 1;
2292 b0 = vlib_get_buffer (vm, bi0);
2294 tcp_half_open_connection_get (vnet_buffer (b0)->
2295 tcp.connection_index);
2296 if (PREDICT_FALSE (tc0 == 0))
2298 error0 = TCP_ERROR_INVALID_CONNECTION;
2302 /* Half-open completed recently but the connection was't removed
2303 * yet by the owning thread */
2304 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2306 /* Make sure the connection actually exists */
2307 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2308 my_thread_index, is_ip4));
2312 ack0 = vnet_buffer (b0)->tcp.ack_number;
2313 seq0 = vnet_buffer (b0)->tcp.seq_number;
2314 tcp0 = tcp_buffer_hdr (b0);
2316 /* Crude check to see if the connection handle does not match
2317 * the packet. Probably connection just switched to established */
2318 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2319 || tcp0->src_port != tc0->c_rmt_port))
2323 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
2326 /* SYNs, FINs and data consume sequence numbers */
2327 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
2328 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
2331 * 1. check the ACK bit
2335 * If the ACK bit is set
2336 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2337 * the RST bit is set, if so drop the segment and return)
2338 * <SEQ=SEG.ACK><CTL=RST>
2339 * and discard the segment. Return.
2340 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2344 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2346 clib_warning ("ack not in rcv wnd");
2347 if (!tcp_rst (tcp0))
2348 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2352 /* Make sure ACK is valid */
2353 if (seq_gt (tc0->snd_una, ack0))
2355 clib_warning ("ack invalid");
2361 * 2. check the RST bit
2366 /* If ACK is acceptable, signal client that peer is not
2367 * willing to accept connection and drop connection*/
2369 tcp_connection_reset (tc0);
2374 * 3. check the security and precedence (skipped)
2378 * 4. check the SYN bit
2381 /* No SYN flag. Drop. */
2382 if (!tcp_syn (tcp0))
2384 clib_warning ("not synack");
2389 if (tcp_options_parse (tcp0, &tc0->rcv_opts))
2391 clib_warning ("options parse fail");
2395 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2396 * current thread pool. */
2397 pool_get (tm->connections[my_thread_index], new_tc0);
2398 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
2399 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2400 new_tc0->c_thread_index = my_thread_index;
2401 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2402 new_tc0->irs = seq0;
2403 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
2404 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] =
2405 TCP_TIMER_HANDLE_INVALID;
2406 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2408 /* If this is not the owning thread, wait for syn retransmit to
2409 * expire and cleanup then */
2410 if (tcp_half_open_connection_cleanup (tc0))
2411 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2413 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2415 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2416 new_tc0->tsval_recent_age = tcp_time_now ();
2419 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2420 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2422 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2423 << new_tc0->snd_wscale;
2424 new_tc0->snd_wl1 = seq0;
2425 new_tc0->snd_wl2 = ack0;
2427 tcp_connection_init_vars (new_tc0);
2429 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2430 if (PREDICT_TRUE (tcp_ack (tcp0)))
2432 /* Our SYN is ACKed: we have iss < ack = snd_una */
2434 /* TODO Dequeue acknowledged segments if we support Fast Open */
2435 new_tc0->snd_una = ack0;
2436 new_tc0->state = TCP_STATE_ESTABLISHED;
2438 /* Make sure las is initialized for the wnd computation */
2439 new_tc0->rcv_las = new_tc0->rcv_nxt;
2441 /* Notify app that we have connection. If session layer can't
2442 * allocate session send reset */
2443 if (session_stream_connect_notify (&new_tc0->connection, 0))
2445 clib_warning ("connect notify fail");
2446 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2447 tcp_connection_cleanup (new_tc0);
2451 /* Make sure after data segment processing ACK is sent */
2452 new_tc0->flags |= TCP_CONN_SNDACK;
2454 /* Update rtt with the syn-ack sample */
2455 tcp_update_rtt (new_tc0, vnet_buffer (b0)->tcp.ack_number);
2456 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2458 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2461 new_tc0->state = TCP_STATE_SYN_RCVD;
2463 /* Notify app that we have connection */
2464 if (session_stream_connect_notify (&new_tc0->connection, 0))
2466 tcp_connection_cleanup (new_tc0);
2467 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2468 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2473 tcp_init_snd_vars (tc0);
2474 tcp_make_synack (new_tc0, b0);
2475 next0 = tcp_next_output (is_ip4);
2480 /* Read data, if any */
2481 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2483 clib_warning ("rcvd data in syn-sent");
2484 error0 = tcp_segment_rcv (new_tc0, b0, &next0);
2485 if (error0 == TCP_ERROR_ACK_OK)
2486 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2487 tcp_maybe_inc_counter (syn_sent, error0, 1);
2491 tcp_make_ack (new_tc0, b0);
2492 next0 = tcp_next_output (new_tc0->c_is_ip4);
2497 b0->error = error0 ? node->errors[error0] : 0;
2499 ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2501 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2502 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2503 clib_memcpy (&t0->tcp_connection, tc0,
2504 sizeof (t0->tcp_connection));
2507 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2508 n_left_to_next, bi0, next0);
2511 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2514 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2516 tcp_inc_counter (syn_sent, TCP_ERROR_EVENT_FIFO_FULL, errors);
2517 return from_frame->n_vectors;
2521 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2522 vlib_frame_t * from_frame)
2524 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2528 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2529 vlib_frame_t * from_frame)
2531 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2535 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2537 .function = tcp4_syn_sent,
2538 .name = "tcp4-syn-sent",
2539 /* Takes a vector of packets. */
2540 .vector_size = sizeof (u32),
2541 .n_errors = TCP_N_ERROR,
2542 .error_strings = tcp_error_strings,
2543 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2546 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2547 foreach_tcp_state_next
2550 .format_trace = format_tcp_rx_trace_short,
2554 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2557 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2559 .function = tcp6_syn_sent_rcv,
2560 .name = "tcp6-syn-sent",
2561 /* Takes a vector of packets. */
2562 .vector_size = sizeof (u32),
2563 .n_errors = TCP_N_ERROR,
2564 .error_strings = tcp_error_strings,
2565 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2568 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2569 foreach_tcp_state_next
2572 .format_trace = format_tcp_rx_trace_short,
2576 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2578 vlib_node_registration_t tcp4_rcv_process_node;
2579 vlib_node_registration_t tcp6_rcv_process_node;
2582 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2583 * as per RFC793 p. 64
2586 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2587 vlib_frame_t * from_frame, int is_ip4)
2589 u32 n_left_from, next_index, *from, *to_next, n_fins = 0;
2590 u32 my_thread_index = vm->thread_index, errors = 0;
2592 from = vlib_frame_vector_args (from_frame);
2593 n_left_from = from_frame->n_vectors;
2594 next_index = node->cached_next_index;
2596 while (n_left_from > 0)
2600 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2602 while (n_left_from > 0 && n_left_to_next > 0)
2606 tcp_header_t *tcp0 = 0;
2607 tcp_connection_t *tc0;
2608 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_NONE;
2616 n_left_to_next -= 1;
2618 b0 = vlib_get_buffer (vm, bi0);
2619 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2621 if (PREDICT_FALSE (tc0 == 0))
2623 error0 = TCP_ERROR_INVALID_CONNECTION;
2627 tcp0 = tcp_buffer_hdr (b0);
2628 is_fin0 = tcp_is_fin (tcp0);
2630 /* SYNs, FINs and data consume sequence numbers */
2631 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2632 + tcp_is_syn (tcp0) + is_fin0 + vnet_buffer (b0)->tcp.data_len;
2636 tcp_connection_t *tmp;
2637 tmp = tcp_lookup_connection (tc0->c_fib_index, b0,
2638 my_thread_index, is_ip4);
2639 if (tmp->state != tc0->state)
2641 clib_warning ("state changed");
2647 * Special treatment for CLOSED
2649 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2651 error0 = TCP_ERROR_CONNECTION_CLOSED;
2656 * For all other states (except LISTEN)
2659 /* 1-4: check SEQ, RST, SYN */
2660 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, tcp0,
2663 tcp_maybe_inc_counter (rcv_process, error0, 1);
2667 /* 5: check the ACK field */
2670 case TCP_STATE_SYN_RCVD:
2672 * If the segment acknowledgment is not acceptable, form a
2674 * <SEQ=SEG.ACK><CTL=RST>
2677 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2679 TCP_DBG ("connection not accepted");
2680 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2681 error0 = TCP_ERROR_ACK_INVALID;
2685 /* Update rtt and rto */
2686 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
2688 /* Switch state to ESTABLISHED */
2689 tc0->state = TCP_STATE_ESTABLISHED;
2690 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2692 /* Initialize session variables */
2693 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2694 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2695 << tc0->rcv_opts.wscale;
2696 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2697 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2699 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2700 tcp_retransmit_timer_reset (tc0);
2701 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2702 stream_session_accept_notify (&tc0->connection);
2703 error0 = TCP_ERROR_ACK_OK;
2705 case TCP_STATE_ESTABLISHED:
2706 /* We can get packets in established state here because they
2707 * were enqueued before state change */
2708 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2710 tcp_maybe_inc_counter (rcv_process, error0, 1);
2715 case TCP_STATE_FIN_WAIT_1:
2716 /* In addition to the processing for the ESTABLISHED state, if
2717 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2718 * continue processing in that state. */
2719 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2721 tcp_maybe_inc_counter (rcv_process, error0, 1);
2725 /* Still have to send the FIN */
2726 if (tc0->flags & TCP_CONN_FINPNDG)
2728 /* TX fifo finally drained */
2729 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2732 /* If FIN is ACKed */
2733 else if (tc0->snd_una == tc0->snd_una_max)
2735 tc0->state = TCP_STATE_FIN_WAIT_2;
2736 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2738 /* Stop all retransmit timers because we have nothing more
2739 * to send. Enable waitclose though because we're willing to
2740 * wait for peer's FIN but not indefinitely. */
2741 tcp_connection_timers_reset (tc0);
2742 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2745 case TCP_STATE_FIN_WAIT_2:
2746 /* In addition to the processing for the ESTABLISHED state, if
2747 * the retransmission queue is empty, the user's CLOSE can be
2748 * acknowledged ("ok") but do not delete the TCB. */
2749 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2751 tcp_maybe_inc_counter (rcv_process, error0, 1);
2755 case TCP_STATE_CLOSE_WAIT:
2756 /* Do the same processing as for the ESTABLISHED state. */
2757 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2759 tcp_maybe_inc_counter (rcv_process, error0, 1);
2762 if (tc0->flags & TCP_CONN_FINPNDG)
2764 /* TX fifo finally drained */
2765 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2768 tcp_connection_timers_reset (tc0);
2769 tc0->state = TCP_STATE_LAST_ACK;
2770 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2775 case TCP_STATE_CLOSING:
2776 /* In addition to the processing for the ESTABLISHED state, if
2777 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2778 * otherwise ignore the segment. */
2779 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2781 tcp_maybe_inc_counter (rcv_process, error0, 1);
2785 tc0->state = TCP_STATE_TIME_WAIT;
2786 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2787 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2791 case TCP_STATE_LAST_ACK:
2792 /* The only thing that [should] arrive in this state is an
2793 * acknowledgment of our FIN. If our FIN is now acknowledged,
2794 * delete the TCB, enter the CLOSED state, and return. */
2796 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2798 error0 = TCP_ERROR_ACK_INVALID;
2801 error0 = TCP_ERROR_ACK_OK;
2802 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2803 /* Apparently our ACK for the peer's FIN was lost */
2804 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2810 tc0->state = TCP_STATE_CLOSED;
2811 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2813 /* Don't free the connection from the data path since
2814 * we can't ensure that we have no packets already enqueued
2815 * to output. Rely instead on the waitclose timer */
2816 tcp_connection_timers_reset (tc0);
2817 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, 1);
2822 case TCP_STATE_TIME_WAIT:
2823 /* The only thing that can arrive in this state is a
2824 * retransmission of the remote FIN. Acknowledge it, and restart
2825 * the 2 MSL timeout. */
2827 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2829 tcp_maybe_inc_counter (rcv_process, error0, 1);
2833 tcp_make_ack (tc0, b0);
2834 next0 = tcp_next_output (is_ip4);
2835 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2843 /* 6: check the URG bit TODO */
2845 /* 7: process the segment text */
2848 case TCP_STATE_ESTABLISHED:
2849 case TCP_STATE_FIN_WAIT_1:
2850 case TCP_STATE_FIN_WAIT_2:
2851 if (vnet_buffer (b0)->tcp.data_len)
2853 error0 = tcp_segment_rcv (tc0, b0, &next0);
2854 tcp_maybe_inc_counter (rcv_process, error0, 1);
2859 case TCP_STATE_CLOSE_WAIT:
2860 case TCP_STATE_CLOSING:
2861 case TCP_STATE_LAST_ACK:
2862 case TCP_STATE_TIME_WAIT:
2863 /* This should not occur, since a FIN has been received from the
2864 * remote side. Ignore the segment text. */
2868 /* 8: check the FIN bit */
2874 case TCP_STATE_ESTABLISHED:
2875 case TCP_STATE_SYN_RCVD:
2876 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2877 tcp_connection_timers_reset (tc0);
2878 tcp_make_fin (tc0, b0);
2880 tc0->snd_una_max = tc0->snd_nxt;
2881 tcp_retransmit_timer_set (tc0);
2882 next0 = tcp_next_output (tc0->c_is_ip4);
2883 stream_session_disconnect_notify (&tc0->connection);
2884 tc0->state = TCP_STATE_CLOSE_WAIT;
2885 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2887 case TCP_STATE_CLOSE_WAIT:
2888 case TCP_STATE_CLOSING:
2889 case TCP_STATE_LAST_ACK:
2892 case TCP_STATE_FIN_WAIT_1:
2893 tc0->state = TCP_STATE_CLOSING;
2894 tcp_make_ack (tc0, b0);
2895 next0 = tcp_next_output (is_ip4);
2896 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2897 /* Wait for ACK but not forever */
2898 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2900 case TCP_STATE_FIN_WAIT_2:
2901 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2902 tc0->state = TCP_STATE_TIME_WAIT;
2903 tcp_connection_timers_reset (tc0);
2904 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2905 tcp_make_ack (tc0, b0);
2906 next0 = tcp_next_output (is_ip4);
2907 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2909 case TCP_STATE_TIME_WAIT:
2910 /* Remain in the TIME-WAIT state. Restart the time-wait
2913 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2916 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2920 b0->error = error0 ? node->errors[error0] : 0;
2922 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2924 tcp_rx_trace_t *t0 =
2925 vlib_add_trace (vm, node, b0, sizeof (*t0));
2926 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2929 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2930 n_left_to_next, bi0, next0);
2933 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2936 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2938 tcp_inc_counter (rcv_process, TCP_ERROR_EVENT_FIFO_FULL, errors);
2939 tcp_inc_counter (rcv_process, TCP_ERROR_FIN_RCVD, n_fins);
2940 return from_frame->n_vectors;
2944 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2945 vlib_frame_t * from_frame)
2947 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2951 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2952 vlib_frame_t * from_frame)
2954 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2958 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2960 .function = tcp4_rcv_process,
2961 .name = "tcp4-rcv-process",
2962 /* Takes a vector of packets. */
2963 .vector_size = sizeof (u32),
2964 .n_errors = TCP_N_ERROR,
2965 .error_strings = tcp_error_strings,
2966 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2969 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2970 foreach_tcp_state_next
2973 .format_trace = format_tcp_rx_trace_short,
2977 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2980 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2982 .function = tcp6_rcv_process,
2983 .name = "tcp6-rcv-process",
2984 /* Takes a vector of packets. */
2985 .vector_size = sizeof (u32),
2986 .n_errors = TCP_N_ERROR,
2987 .error_strings = tcp_error_strings,
2988 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2991 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2992 foreach_tcp_state_next
2995 .format_trace = format_tcp_rx_trace_short,
2999 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
3001 vlib_node_registration_t tcp4_listen_node;
3002 vlib_node_registration_t tcp6_listen_node;
3005 * LISTEN state processing as per RFC 793 p. 65
3008 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3009 vlib_frame_t * from_frame, int is_ip4)
3011 u32 n_left_from, next_index, *from, *to_next, n_syns = 0;
3012 u32 my_thread_index = vm->thread_index;
3014 from = vlib_frame_vector_args (from_frame);
3015 n_left_from = from_frame->n_vectors;
3017 next_index = node->cached_next_index;
3019 while (n_left_from > 0)
3023 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
3025 while (n_left_from > 0 && n_left_to_next > 0)
3030 tcp_header_t *th0 = 0;
3031 tcp_connection_t *lc0;
3034 tcp_connection_t *child0;
3035 u32 error0 = TCP_ERROR_NONE, next0 = tcp_next_drop (is_ip4);
3042 n_left_to_next -= 1;
3044 b0 = vlib_get_buffer (vm, bi0);
3045 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3049 ip40 = vlib_buffer_get_current (b0);
3050 th0 = ip4_next_header (ip40);
3054 ip60 = vlib_buffer_get_current (b0);
3055 th0 = ip6_next_header (ip60);
3058 /* Create child session. For syn-flood protection use filter */
3060 /* 1. first check for an RST: handled in dispatch */
3061 /* if (tcp_rst (th0))
3064 /* 2. second check for an ACK: handled in dispatch */
3065 /* if (tcp_ack (th0))
3067 tcp_send_reset (b0, is_ip4);
3071 /* 3. check for a SYN (did that already) */
3073 /* Make sure connection wasn't just created */
3074 child0 = tcp_lookup_connection (lc0->c_fib_index, b0,
3075 my_thread_index, is_ip4);
3076 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3078 error0 = TCP_ERROR_CREATE_EXISTS;
3082 /* Create child session and send SYN-ACK */
3083 child0 = tcp_connection_new (my_thread_index);
3084 child0->c_lcl_port = th0->dst_port;
3085 child0->c_rmt_port = th0->src_port;
3086 child0->c_is_ip4 = is_ip4;
3087 child0->state = TCP_STATE_SYN_RCVD;
3088 child0->c_fib_index = lc0->c_fib_index;
3092 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3093 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3097 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
3098 sizeof (ip6_address_t));
3099 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
3100 sizeof (ip6_address_t));
3103 if (tcp_options_parse (th0, &child0->rcv_opts))
3105 clib_warning ("options parse fail");
3109 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3110 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3111 child0->rcv_las = child0->rcv_nxt;
3112 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3114 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3115 * segments are used to initialize PAWS. */
3116 if (tcp_opts_tstamp (&child0->rcv_opts))
3118 child0->tsval_recent = child0->rcv_opts.tsval;
3119 child0->tsval_recent_age = tcp_time_now ();
3122 if (tcp_opts_wscale (&child0->rcv_opts))
3123 child0->snd_wscale = child0->rcv_opts.wscale;
3125 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3126 << child0->snd_wscale;
3127 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3128 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3130 tcp_connection_init_vars (child0);
3131 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
3133 if (stream_session_accept (&child0->connection, lc0->c_s_index,
3136 clib_warning ("session accept fail");
3137 tcp_connection_cleanup (child0);
3138 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3142 /* Reuse buffer to make syn-ack and send */
3143 tcp_make_synack (child0, b0);
3144 next0 = tcp_next_output (is_ip4);
3145 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
3148 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3150 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3151 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3152 clib_memcpy (&t0->tcp_connection, lc0,
3153 sizeof (t0->tcp_connection));
3156 n_syns += (error0 == TCP_ERROR_NONE);
3157 b0->error = node->errors[error0];
3159 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
3160 n_left_to_next, bi0, next0);
3163 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
3166 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3167 return from_frame->n_vectors;
3171 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3172 vlib_frame_t * from_frame)
3174 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3178 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3179 vlib_frame_t * from_frame)
3181 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3185 VLIB_REGISTER_NODE (tcp4_listen_node) =
3187 .function = tcp4_listen,
3188 .name = "tcp4-listen",
3189 /* Takes a vector of packets. */
3190 .vector_size = sizeof (u32),
3191 .n_errors = TCP_N_ERROR,
3192 .error_strings = tcp_error_strings,
3193 .n_next_nodes = TCP_LISTEN_N_NEXT,
3196 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3197 foreach_tcp_state_next
3200 .format_trace = format_tcp_rx_trace_short,
3204 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
3207 VLIB_REGISTER_NODE (tcp6_listen_node) =
3209 .function = tcp6_listen,
3210 .name = "tcp6-listen",
3211 /* Takes a vector of packets. */
3212 .vector_size = sizeof (u32),
3213 .n_errors = TCP_N_ERROR,
3214 .error_strings = tcp_error_strings,
3215 .n_next_nodes = TCP_LISTEN_N_NEXT,
3218 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3219 foreach_tcp_state_next
3222 .format_trace = format_tcp_rx_trace_short,
3226 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
3228 vlib_node_registration_t tcp4_input_node;
3229 vlib_node_registration_t tcp6_input_node;
3231 typedef enum _tcp_input_next
3233 TCP_INPUT_NEXT_DROP,
3234 TCP_INPUT_NEXT_LISTEN,
3235 TCP_INPUT_NEXT_RCV_PROCESS,
3236 TCP_INPUT_NEXT_SYN_SENT,
3237 TCP_INPUT_NEXT_ESTABLISHED,
3238 TCP_INPUT_NEXT_RESET,
3239 TCP_INPUT_NEXT_PUNT,
3243 #define foreach_tcp4_input_next \
3244 _ (DROP, "ip4-drop") \
3245 _ (LISTEN, "tcp4-listen") \
3246 _ (RCV_PROCESS, "tcp4-rcv-process") \
3247 _ (SYN_SENT, "tcp4-syn-sent") \
3248 _ (ESTABLISHED, "tcp4-established") \
3249 _ (RESET, "tcp4-reset") \
3250 _ (PUNT, "ip4-punt")
3252 #define foreach_tcp6_input_next \
3253 _ (DROP, "ip6-drop") \
3254 _ (LISTEN, "tcp6-listen") \
3255 _ (RCV_PROCESS, "tcp6-rcv-process") \
3256 _ (SYN_SENT, "tcp6-syn-sent") \
3257 _ (ESTABLISHED, "tcp6-established") \
3258 _ (RESET, "tcp6-reset") \
3259 _ (PUNT, "ip6-punt")
3261 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3264 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3265 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3267 tcp_connection_t *tc;
3272 for (i = 0; i < n_bufs; i++)
3274 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3276 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3277 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3279 tcp = vlib_buffer_get_current (bs[i]);
3280 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3286 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3288 if (*error == TCP_ERROR_FILTERED)
3290 *next = TCP_INPUT_NEXT_DROP;
3292 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3294 *next = TCP_INPUT_NEXT_PUNT;
3295 *error = TCP_ERROR_PUNT;
3299 *next = TCP_INPUT_NEXT_RESET;
3300 *error = TCP_ERROR_NO_LISTENER;
3304 static inline tcp_connection_t *
3305 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3308 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3309 int n_advance_bytes, n_data_bytes;
3310 transport_connection_t *tc;
3316 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3317 tcp = ip4_next_header (ip4);
3318 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3319 n_advance_bytes = (ip4_header_bytes (ip4) + tcp_header_bytes (tcp));
3320 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3322 /* Length check. Checksum computed by ipx_local no need to compute again */
3323 if (PREDICT_FALSE (n_advance_bytes < 0))
3325 *error = TCP_ERROR_LENGTH;
3329 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3330 &ip4->src_address, tcp->dst_port,
3331 tcp->src_port, TRANSPORT_PROTO_TCP,
3332 thread_index, &is_filtered);
3336 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3337 tcp = ip6_next_header (ip6);
3338 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3339 n_advance_bytes = tcp_header_bytes (tcp);
3340 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3342 n_advance_bytes += sizeof (ip6[0]);
3344 if (PREDICT_FALSE (n_advance_bytes < 0))
3346 *error = TCP_ERROR_LENGTH;
3350 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3351 &ip6->src_address, tcp->dst_port,
3352 tcp->src_port, TRANSPORT_PROTO_TCP,
3353 thread_index, &is_filtered);
3356 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3357 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3358 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3359 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3360 vnet_buffer (b)->tcp.flags = 0;
3362 *error = is_filtered ? TCP_ERROR_FILTERED : *error;
3364 return tcp_get_connection_from_transport (tc);
3368 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3369 vlib_buffer_t * b, u16 * next, u32 * error)
3374 tcp = tcp_buffer_hdr (b);
3375 flags = tcp->flags & filter_flags;
3376 *next = tm->dispatch_table[tc->state][flags].next;
3377 *error = tm->dispatch_table[tc->state][flags].error;
3379 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3380 || *next == TCP_INPUT_NEXT_RESET))
3382 /* Overload tcp flags to store state */
3383 tcp_state_t state = tc->state;
3384 vnet_buffer (b)->tcp.flags = tc->state;
3386 if (*error == TCP_ERROR_DISPATCH)
3387 clib_warning ("disp error state %U flags %U", format_tcp_state,
3388 state, format_tcp_flags, (int) flags);
3393 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3394 vlib_frame_t * frame, int is_ip4)
3396 u32 n_left_from, *from, thread_index = vm->thread_index;
3397 tcp_main_t *tm = vnet_get_tcp_main ();
3398 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3399 u16 nexts[VLIB_FRAME_SIZE], *next;
3401 tcp_set_time_now (tcp_get_worker (thread_index));
3403 from = vlib_frame_vector_args (frame);
3404 n_left_from = frame->n_vectors;
3405 vlib_get_buffers (vm, from, bufs, n_left_from);
3410 while (n_left_from >= 4)
3412 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3413 tcp_connection_t *tc0, *tc1;
3416 vlib_prefetch_buffer_header (b[2], STORE);
3417 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3419 vlib_prefetch_buffer_header (b[3], STORE);
3420 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3423 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3425 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3426 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4);
3428 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3430 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3431 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3433 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3434 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3436 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3437 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3441 if (PREDICT_TRUE (tc0 != 0))
3443 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3444 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3445 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3448 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3450 if (PREDICT_TRUE (tc1 != 0))
3452 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3453 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3454 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3457 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3464 while (n_left_from > 0)
3466 tcp_connection_t *tc0;
3467 u32 error0 = TCP_ERROR_NO_LISTENER;
3469 if (n_left_from > 1)
3471 vlib_prefetch_buffer_header (b[1], STORE);
3472 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3475 next[0] = TCP_INPUT_NEXT_DROP;
3476 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3477 if (PREDICT_TRUE (tc0 != 0))
3479 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3480 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3481 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3484 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3491 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3492 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3494 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3495 return frame->n_vectors;
3499 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3500 vlib_frame_t * from_frame)
3502 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3506 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3507 vlib_frame_t * from_frame)
3509 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3513 VLIB_REGISTER_NODE (tcp4_input_node) =
3515 .function = tcp4_input,
3516 .name = "tcp4-input",
3517 /* Takes a vector of packets. */
3518 .vector_size = sizeof (u32),
3519 .n_errors = TCP_N_ERROR,
3520 .error_strings = tcp_error_strings,
3521 .n_next_nodes = TCP_INPUT_N_NEXT,
3524 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3525 foreach_tcp4_input_next
3528 .format_buffer = format_tcp_header,
3529 .format_trace = format_tcp_rx_trace,
3533 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3536 VLIB_REGISTER_NODE (tcp6_input_node) =
3538 .function = tcp6_input,
3539 .name = "tcp6-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_tcp6_input_next
3551 .format_buffer = format_tcp_header,
3552 .format_trace = format_tcp_rx_trace,
3556 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3559 tcp_dispatch_table_init (tcp_main_t * tm)
3562 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3563 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3565 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3566 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3569 #define _(t,f,n,e) \
3571 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3572 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3575 /* SYNs for new connections -> tcp-listen. */
3576 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3577 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3578 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_RST_RCVD);
3579 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3581 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3582 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3583 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3584 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3586 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3587 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3589 /* SYN-ACK for a SYN */
3590 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3592 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3593 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3594 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3596 /* ACK for for established connection -> tcp-established. */
3597 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3598 /* FIN for for established connection -> tcp-established. */
3599 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3600 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3602 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3603 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3605 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3606 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3608 /* ACK or FIN-ACK to our FIN */
3609 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3610 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3612 /* FIN in reply to our FIN from the other side */
3613 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3614 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3615 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3616 /* FIN confirming that the peer (app) has closed */
3617 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3618 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3619 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3621 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3622 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3624 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3625 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3626 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3628 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3629 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3630 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3631 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3633 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3634 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3635 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3636 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3637 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3638 TCP_ERROR_CONNECTION_CLOSED);
3642 static clib_error_t *
3643 tcp_input_init (vlib_main_t * vm)
3645 clib_error_t *error = 0;
3646 tcp_main_t *tm = vnet_get_tcp_main ();
3648 if ((error = vlib_call_init_function (vm, tcp_init)))
3651 /* Initialize dispatch table. */
3652 tcp_dispatch_table_init (tm);
3657 VLIB_INIT_FUNCTION (tcp_input_init);
3660 * fd.io coding-style-patch-verification: ON
3663 * eval: (c-set-style "gnu")