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,
723 u8 * can_rescue, u8 * snd_limited)
725 sack_scoreboard_hole_t *hole = 0;
727 hole = start ? start : scoreboard_first_hole (sb);
728 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
729 hole = scoreboard_next_hole (sb, hole);
731 /* Nothing, return */
734 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
738 /* Rule (1): if higher than rxt, less than high_sacked and lost */
739 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
741 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
745 /* Rule (2): output takes care of transmitting new data */
746 if (!have_sent_1_smss)
749 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
751 /* Rule (3): if hole not lost */
752 else if (seq_lt (hole->start, sb->high_sacked))
755 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
757 /* Rule (4): if hole beyond high_sacked */
760 ASSERT (seq_geq (hole->start, sb->high_sacked));
763 /* HighRxt MUST NOT be updated */
768 if (hole && seq_lt (sb->high_rxt, hole->start))
769 sb->high_rxt = hole->start;
775 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 seq)
777 sack_scoreboard_hole_t *hole;
778 hole = scoreboard_first_hole (sb);
781 seq = seq_gt (seq, hole->start) ? seq : hole->start;
782 sb->cur_rxt_hole = sb->head;
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 (wrk->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);
1309 tc->sack_sb.rescue_rxt = tc->snd_una - 1;
1313 /* Post retransmit update cwnd to ssthresh and account for the
1314 * three segments that have left the network and should've been
1315 * buffered at the receiver XXX */
1316 tc->cwnd = tc->ssthresh + 3 * tc->snd_mss;
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 /* XXX limit this only to first partial ack? */
1391 tcp_retransmit_timer_force_update (tc);
1393 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1394 * reset dupacks to 0. Also needed if in congestion recovery */
1395 tc->rcv_dupacks = 0;
1397 /* Post RTO timeout don't try anything fancy */
1398 if (tcp_in_recovery (tc))
1400 tcp_cc_rcv_ack (tc);
1401 transport_add_tx_event (&tc->connection);
1405 /* Remove retransmitted bytes that have been delivered */
1406 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1408 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1409 >= tc->sack_sb.last_bytes_delivered
1410 || (tc->flags & TCP_CONN_FINSNT));
1412 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1413 * remove sacked bytes delivered */
1414 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1416 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1417 - tc->sack_sb.last_bytes_delivered;
1418 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1419 tc->snd_rxt_bytes -= rxt_delivered;
1423 /* Apparently all retransmitted holes have been acked */
1424 tc->snd_rxt_bytes = 0;
1429 if (tc->snd_rxt_bytes > tc->bytes_acked)
1430 tc->snd_rxt_bytes -= tc->bytes_acked;
1432 tc->snd_rxt_bytes = 0;
1435 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1438 * Since this was a partial ack, try to retransmit some more data
1440 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1444 * Process incoming ACK
1447 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
1448 tcp_header_t * th, u32 * next, u32 * error)
1450 u32 prev_snd_wnd, prev_snd_una;
1453 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1455 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1456 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1458 /* When we entered recovery, we reset snd_nxt to snd_una. Seems peer
1459 * still has the data so accept the ack */
1460 if (tcp_in_recovery (tc)
1461 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_congestion))
1463 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1464 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
1465 tc->snd_una_max = tc->snd_nxt;
1469 /* If we have outstanding data and this is within the window, accept it,
1470 * probably retransmit has timed out. Otherwise ACK segment and then
1472 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1474 tcp_make_ack (tc, b);
1475 *next = tcp_next_output (tc->c_is_ip4);
1476 *error = TCP_ERROR_ACK_INVALID;
1477 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1478 vnet_buffer (b)->tcp.ack_number);
1482 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1483 vnet_buffer (b)->tcp.ack_number);
1485 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1486 *error = TCP_ERROR_ACK_FUTURE;
1489 /* If old ACK, probably it's an old dupack */
1490 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1492 *error = TCP_ERROR_ACK_OLD;
1493 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1494 vnet_buffer (b)->tcp.ack_number);
1495 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1496 tcp_cc_handle_event (tc, 1);
1497 /* Don't drop yet */
1502 * Looks okay, process feedback
1505 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1506 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1508 prev_snd_wnd = tc->snd_wnd;
1509 prev_snd_una = tc->snd_una;
1510 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1511 vnet_buffer (b)->tcp.ack_number,
1512 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1513 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1514 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1515 tcp_validate_txf_size (tc, tc->bytes_acked);
1517 if (tc->bytes_acked)
1518 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
1520 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1523 * Check if we have congestion event
1526 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1528 tcp_cc_handle_event (tc, is_dack);
1529 if (!tcp_in_cong_recovery (tc))
1531 *error = TCP_ERROR_ACK_DUP;
1532 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1538 * Update congestion control (slow start/congestion avoidance)
1540 tcp_cc_update (tc, b);
1541 *error = TCP_ERROR_ACK_OK;
1546 tcp_sack_vector_is_sane (sack_block_t * sacks)
1549 for (i = 1; i < vec_len (sacks); i++)
1551 if (sacks[i - 1].end == sacks[i].start)
1558 * Build SACK list as per RFC2018.
1560 * Makes sure the first block contains the segment that generated the current
1561 * ACK and the following ones are the ones most recently reported in SACK
1564 * @param tc TCP connection for which the SACK list is updated
1565 * @param start Start sequence number of the newest SACK block
1566 * @param end End sequence of the newest SACK block
1569 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1571 sack_block_t *new_list = 0, *block = 0;
1574 /* If the first segment is ooo add it to the list. Last write might've moved
1575 * rcv_nxt over the first segment. */
1576 if (seq_lt (tc->rcv_nxt, start))
1578 vec_add2 (new_list, block, 1);
1579 block->start = start;
1583 /* Find the blocks still worth keeping. */
1584 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1586 /* Discard if rcv_nxt advanced beyond current block */
1587 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1590 /* Merge or drop if segment overlapped by the new segment */
1591 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1592 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1594 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1595 new_list[0].start = tc->snd_sacks[i].start;
1596 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1597 new_list[0].end = tc->snd_sacks[i].end;
1601 /* Save to new SACK list if we have space. */
1602 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1604 vec_add1 (new_list, tc->snd_sacks[i]);
1608 clib_warning ("sack discarded");
1612 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1614 /* Replace old vector with new one */
1615 vec_free (tc->snd_sacks);
1616 tc->snd_sacks = new_list;
1618 /* Segments should not 'touch' */
1619 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1623 tcp_sack_list_bytes (tcp_connection_t * tc)
1626 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1627 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1631 /** Enqueue data for delivery to application */
1633 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1636 int written, error = TCP_ERROR_ENQUEUED;
1638 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1640 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1641 1 /* queue event */ , 1);
1643 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1645 /* Update rcv_nxt */
1646 if (PREDICT_TRUE (written == data_len))
1648 tc->rcv_nxt += written;
1650 /* If more data written than expected, account for out-of-order bytes. */
1651 else if (written > data_len)
1653 tc->rcv_nxt += written;
1655 /* Send ACK confirming the update */
1656 tc->flags |= TCP_CONN_SNDACK;
1657 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1659 else if (written > 0)
1661 /* We've written something but FIFO is probably full now */
1662 tc->rcv_nxt += written;
1664 /* Depending on how fast the app is, all remaining buffers in burst will
1665 * not be enqueued. Inform peer */
1666 tc->flags |= TCP_CONN_SNDACK;
1668 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1672 tc->flags |= TCP_CONN_SNDACK;
1673 return TCP_ERROR_FIFO_FULL;
1676 /* Update SACK list if need be */
1677 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1679 /* Remove SACK blocks that have been delivered */
1680 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1686 /** Enqueue out-of-order data */
1688 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1691 stream_session_t *s0;
1694 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1697 /* Enqueue out-of-order data with relative offset */
1698 rv = session_enqueue_stream_connection (&tc->connection, b,
1699 vnet_buffer (b)->tcp.seq_number -
1700 tc->rcv_nxt, 0 /* queue event */ ,
1703 /* Nothing written */
1706 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1707 return TCP_ERROR_FIFO_FULL;
1710 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1712 /* Update SACK list if in use */
1713 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1715 ooo_segment_t *newest;
1718 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1720 /* Get the newest segment from the fifo */
1721 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1724 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1725 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1726 start = tc->rcv_nxt + offset;
1727 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1728 tcp_update_sack_list (tc, start, end);
1729 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1730 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1734 return TCP_ERROR_ENQUEUED_OOO;
1738 * Check if ACK could be delayed. If ack can be delayed, it should return
1739 * true for a full frame. If we're always acking return 0.
1742 tcp_can_delack (tcp_connection_t * tc)
1744 /* Send ack if ... */
1746 /* just sent a rcv wnd 0 */
1747 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1748 /* constrained to send ack */
1749 || (tc->flags & TCP_CONN_SNDACK) != 0
1750 /* we're almost out of tx wnd */
1751 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1758 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1760 u32 discard, first = b->current_length;
1761 vlib_main_t *vm = vlib_get_main ();
1763 /* Handle multi-buffer segments */
1764 if (n_bytes_to_drop > b->current_length)
1766 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1770 discard = clib_min (n_bytes_to_drop, b->current_length);
1771 vlib_buffer_advance (b, discard);
1772 b = vlib_get_buffer (vm, b->next_buffer);
1773 n_bytes_to_drop -= discard;
1775 while (n_bytes_to_drop);
1776 if (n_bytes_to_drop > first)
1777 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1780 vlib_buffer_advance (b, n_bytes_to_drop);
1781 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1786 * Receive buffer for connection and handle acks
1788 * It handles both in order or out-of-order data.
1791 tcp_segment_rcv (tcp_connection_t * tc, vlib_buffer_t * b, u32 * next0)
1793 u32 error, n_bytes_to_drop, n_data_bytes;
1795 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1796 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1797 ASSERT (n_data_bytes);
1799 /* Handle out-of-order data */
1800 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1802 /* Old sequence numbers allowed through because they overlapped
1804 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1806 /* Completely in the past (possible retransmit). Ack
1807 * retransmissions since we may not have any data to send */
1808 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1810 tcp_make_ack (tc, b);
1811 error = TCP_ERROR_SEGMENT_OLD;
1812 *next0 = tcp_next_output (tc->c_is_ip4);
1816 /* Chop off the bytes in the past and see if what is left
1817 * can be enqueued in order */
1818 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1819 n_data_bytes -= n_bytes_to_drop;
1820 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1821 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1823 error = TCP_ERROR_SEGMENT_OLD;
1824 *next0 = tcp_next_drop (tc->c_is_ip4);
1830 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1831 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1832 *next0 = tcp_next_output (tc->c_is_ip4);
1833 tcp_make_ack (tc, b);
1834 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1835 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1841 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1842 * segments can be enqueued after fifo tail offset changes. */
1843 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1844 if (tcp_can_delack (tc))
1846 *next0 = tcp_next_drop (tc->c_is_ip4);
1847 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1848 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1852 *next0 = tcp_next_output (tc->c_is_ip4);
1853 tcp_make_ack (tc, b);
1861 tcp_header_t tcp_header;
1862 tcp_connection_t tcp_connection;
1866 format_tcp_rx_trace (u8 * s, va_list * args)
1868 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1869 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1870 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1871 u32 indent = format_get_indent (s);
1873 s = format (s, "%U\n%U%U",
1874 format_tcp_header, &t->tcp_header, 128,
1875 format_white_space, indent,
1876 format_tcp_connection, &t->tcp_connection, 1);
1882 format_tcp_rx_trace_short (u8 * s, va_list * args)
1884 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1885 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1886 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1888 s = format (s, "%d -> %d (%U)",
1889 clib_net_to_host_u16 (t->tcp_header.dst_port),
1890 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
1891 t->tcp_connection.state);
1897 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1898 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1902 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1906 th0 = tcp_buffer_hdr (b0);
1908 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1912 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
1913 vlib_frame_t * frame, u8 is_ip4)
1917 n_left = frame->n_vectors;
1918 from = vlib_frame_vector_args (frame);
1922 tcp_connection_t *tc0;
1929 b0 = vlib_get_buffer (vm, bi0);
1931 if (b0->flags & VLIB_BUFFER_IS_TRACED)
1933 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1934 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1936 th0 = tcp_buffer_hdr (b0);
1937 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1946 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
1947 u8 is_ip4, u32 evt, u32 val)
1950 vlib_node_increment_counter (vm, tcp4_node, evt, val);
1952 vlib_node_increment_counter (vm, tcp6_node, evt, val);
1955 #define tcp_maybe_inc_counter(node_id, err, count) \
1957 if (next0 != tcp_next_drop (is_ip4)) \
1958 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1959 tcp6_##node_id##_node.index, is_ip4, err, \
1962 #define tcp_inc_counter(node_id, err, count) \
1963 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1964 tcp6_##node_id##_node.index, is_ip4, \
1966 #define tcp_maybe_inc_err_counter(cnts, err) \
1968 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
1970 #define tcp_inc_err_counter(cnts, err, val) \
1974 #define tcp_store_err_counters(node_id, cnts) \
1977 for (i = 0; i < TCP_N_ERROR; i++) \
1979 tcp_inc_counter(node_id, i, cnts[i]); \
1984 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1985 vlib_frame_t * frame, int is_ip4)
1987 u32 thread_index = vm->thread_index, errors = 0;
1988 u32 n_left_from, next_index, *from, *to_next;
1989 u16 err_counters[TCP_N_ERROR] = { 0 };
1992 if (node->flags & VLIB_NODE_FLAG_TRACE)
1993 tcp_established_trace_frame (vm, node, frame, is_ip4);
1995 from = vlib_frame_vector_args (frame);
1996 n_left_from = frame->n_vectors;
1997 next_index = node->cached_next_index;
1999 while (n_left_from > 0)
2003 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2004 while (n_left_from > 0 && n_left_to_next > 0)
2008 tcp_header_t *th0 = 0;
2009 tcp_connection_t *tc0;
2010 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ACK_OK;
2012 if (n_left_from > 1)
2015 pb = vlib_get_buffer (vm, from[1]);
2016 vlib_prefetch_buffer_header (pb, LOAD);
2017 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2025 n_left_to_next -= 1;
2027 b0 = vlib_get_buffer (vm, bi0);
2028 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2031 if (PREDICT_FALSE (tc0 == 0))
2033 error0 = TCP_ERROR_INVALID_CONNECTION;
2037 th0 = tcp_buffer_hdr (b0);
2038 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
2039 * dangling reference. */
2040 is_fin = tcp_is_fin (th0);
2042 /* SYNs, FINs and data consume sequence numbers */
2043 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2044 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
2046 /* TODO header prediction fast path */
2048 /* 1-4: check SEQ, RST, SYN */
2049 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0,
2052 tcp_maybe_inc_err_counter (err_counters, error0);
2053 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2057 /* 5: check the ACK field */
2058 if (PREDICT_FALSE (tcp_rcv_ack (tc0, b0, th0, &next0, &error0)))
2060 tcp_maybe_inc_err_counter (err_counters, error0);
2064 /* 6: check the URG bit TODO */
2066 /* 7: process the segment text */
2067 if (vnet_buffer (b0)->tcp.data_len)
2069 error0 = tcp_segment_rcv (tc0, b0, &next0);
2070 tcp_maybe_inc_err_counter (err_counters, error0);
2073 /* 8: check the FIN bit */
2074 if (PREDICT_FALSE (is_fin))
2076 /* Enter CLOSE-WAIT and notify session. To avoid lingering
2077 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
2078 /* Account for the FIN if nothing else was received */
2079 if (vnet_buffer (b0)->tcp.data_len == 0)
2081 tcp_make_ack (tc0, b0);
2082 next0 = tcp_next_output (tc0->c_is_ip4);
2083 tc0->state = TCP_STATE_CLOSE_WAIT;
2084 stream_session_disconnect_notify (&tc0->connection);
2085 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
2086 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2087 tcp_inc_err_counter (err_counters, TCP_ERROR_FIN_RCVD, 1);
2091 b0->error = node->errors[error0];
2092 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2093 n_left_to_next, bi0, next0);
2096 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2099 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2101 err_counters[TCP_ERROR_EVENT_FIFO_FULL] = errors;
2102 tcp_store_err_counters (established, err_counters);
2103 tcp_flush_frame_to_output (tcp_get_worker (thread_index), is_ip4);
2105 return frame->n_vectors;
2109 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2110 vlib_frame_t * from_frame)
2112 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2116 tcp6_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, 0 /* is_ip4 */ );
2123 VLIB_REGISTER_NODE (tcp4_established_node) =
2125 .function = tcp4_established,
2126 .name = "tcp4-established",
2127 /* Takes a vector of packets. */
2128 .vector_size = sizeof (u32),
2129 .n_errors = TCP_N_ERROR,
2130 .error_strings = tcp_error_strings,
2131 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2134 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2135 foreach_tcp_state_next
2138 .format_trace = format_tcp_rx_trace_short,
2142 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
2145 VLIB_REGISTER_NODE (tcp6_established_node) =
2147 .function = tcp6_established,
2148 .name = "tcp6-established",
2149 /* Takes a vector of packets. */
2150 .vector_size = sizeof (u32),
2151 .n_errors = TCP_N_ERROR,
2152 .error_strings = tcp_error_strings,
2153 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2156 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2157 foreach_tcp_state_next
2160 .format_trace = format_tcp_rx_trace_short,
2165 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
2167 vlib_node_registration_t tcp4_syn_sent_node;
2168 vlib_node_registration_t tcp6_syn_sent_node;
2171 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2173 transport_connection_t *tmp = 0;
2180 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2183 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2184 && (tc->state == TCP_STATE_LISTEN
2185 || tc->c_rmt_port == hdr->src_port));
2189 handle = session_lookup_half_open_handle (&tc->connection);
2190 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2191 tc->c_proto, tc->c_is_ip4);
2195 if (tmp->lcl_port == hdr->dst_port
2196 && tmp->rmt_port == hdr->src_port)
2198 TCP_DBG ("half-open is valid!");
2206 * Lookup transport connection
2208 static tcp_connection_t *
2209 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2213 transport_connection_t *tconn;
2214 tcp_connection_t *tc;
2219 ip4 = vlib_buffer_get_current (b);
2220 tcp = ip4_next_header (ip4);
2221 tconn = session_lookup_connection_wt4 (fib_index,
2226 TRANSPORT_PROTO_TCP,
2227 thread_index, &is_filtered);
2228 tc = tcp_get_connection_from_transport (tconn);
2229 ASSERT (tcp_lookup_is_valid (tc, tcp));
2234 ip6 = vlib_buffer_get_current (b);
2235 tcp = ip6_next_header (ip6);
2236 tconn = session_lookup_connection_wt6 (fib_index,
2241 TRANSPORT_PROTO_TCP,
2242 thread_index, &is_filtered);
2243 tc = tcp_get_connection_from_transport (tconn);
2244 ASSERT (tcp_lookup_is_valid (tc, tcp));
2250 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2251 vlib_frame_t * from_frame, int is_ip4)
2253 tcp_main_t *tm = vnet_get_tcp_main ();
2254 u32 n_left_from, next_index, *from, *to_next;
2255 u32 my_thread_index = vm->thread_index, errors = 0;
2257 from = vlib_frame_vector_args (from_frame);
2258 n_left_from = from_frame->n_vectors;
2260 next_index = node->cached_next_index;
2262 while (n_left_from > 0)
2266 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2268 while (n_left_from > 0 && n_left_to_next > 0)
2270 u32 bi0, ack0, seq0;
2273 tcp_header_t *tcp0 = 0;
2274 tcp_connection_t *tc0;
2275 tcp_connection_t *new_tc0;
2276 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ENQUEUED;
2283 n_left_to_next -= 1;
2285 b0 = vlib_get_buffer (vm, bi0);
2287 tcp_half_open_connection_get (vnet_buffer (b0)->
2288 tcp.connection_index);
2289 if (PREDICT_FALSE (tc0 == 0))
2291 error0 = TCP_ERROR_INVALID_CONNECTION;
2295 /* Half-open completed recently but the connection was't removed
2296 * yet by the owning thread */
2297 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2299 /* Make sure the connection actually exists */
2300 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2301 my_thread_index, is_ip4));
2305 ack0 = vnet_buffer (b0)->tcp.ack_number;
2306 seq0 = vnet_buffer (b0)->tcp.seq_number;
2307 tcp0 = tcp_buffer_hdr (b0);
2309 /* Crude check to see if the connection handle does not match
2310 * the packet. Probably connection just switched to established */
2311 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2312 || tcp0->src_port != tc0->c_rmt_port))
2316 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
2319 /* SYNs, FINs and data consume sequence numbers */
2320 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
2321 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
2324 * 1. check the ACK bit
2328 * If the ACK bit is set
2329 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2330 * the RST bit is set, if so drop the segment and return)
2331 * <SEQ=SEG.ACK><CTL=RST>
2332 * and discard the segment. Return.
2333 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2337 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2339 clib_warning ("ack not in rcv wnd");
2340 if (!tcp_rst (tcp0))
2341 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2345 /* Make sure ACK is valid */
2346 if (seq_gt (tc0->snd_una, ack0))
2348 clib_warning ("ack invalid");
2354 * 2. check the RST bit
2359 /* If ACK is acceptable, signal client that peer is not
2360 * willing to accept connection and drop connection*/
2362 tcp_connection_reset (tc0);
2367 * 3. check the security and precedence (skipped)
2371 * 4. check the SYN bit
2374 /* No SYN flag. Drop. */
2375 if (!tcp_syn (tcp0))
2377 clib_warning ("not synack");
2382 if (tcp_options_parse (tcp0, &tc0->rcv_opts))
2384 clib_warning ("options parse fail");
2388 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2389 * current thread pool. */
2390 pool_get (tm->connections[my_thread_index], new_tc0);
2391 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
2392 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2393 new_tc0->c_thread_index = my_thread_index;
2394 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2395 new_tc0->irs = seq0;
2396 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
2397 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] =
2398 TCP_TIMER_HANDLE_INVALID;
2399 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2401 /* If this is not the owning thread, wait for syn retransmit to
2402 * expire and cleanup then */
2403 if (tcp_half_open_connection_cleanup (tc0))
2404 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2406 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2408 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2409 new_tc0->tsval_recent_age = tcp_time_now ();
2412 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2413 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2415 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2416 << new_tc0->snd_wscale;
2417 new_tc0->snd_wl1 = seq0;
2418 new_tc0->snd_wl2 = ack0;
2420 tcp_connection_init_vars (new_tc0);
2422 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2423 if (PREDICT_TRUE (tcp_ack (tcp0)))
2425 /* Our SYN is ACKed: we have iss < ack = snd_una */
2427 /* TODO Dequeue acknowledged segments if we support Fast Open */
2428 new_tc0->snd_una = ack0;
2429 new_tc0->state = TCP_STATE_ESTABLISHED;
2431 /* Make sure las is initialized for the wnd computation */
2432 new_tc0->rcv_las = new_tc0->rcv_nxt;
2434 /* Notify app that we have connection. If session layer can't
2435 * allocate session send reset */
2436 if (session_stream_connect_notify (&new_tc0->connection, 0))
2438 clib_warning ("connect notify fail");
2439 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2440 tcp_connection_cleanup (new_tc0);
2444 /* Make sure after data segment processing ACK is sent */
2445 new_tc0->flags |= TCP_CONN_SNDACK;
2447 /* Update rtt with the syn-ack sample */
2448 tcp_update_rtt (new_tc0, vnet_buffer (b0)->tcp.ack_number);
2449 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2451 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2454 new_tc0->state = TCP_STATE_SYN_RCVD;
2456 /* Notify app that we have connection */
2457 if (session_stream_connect_notify (&new_tc0->connection, 0))
2459 tcp_connection_cleanup (new_tc0);
2460 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2461 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2466 tcp_init_snd_vars (tc0);
2467 tcp_make_synack (new_tc0, b0);
2468 next0 = tcp_next_output (is_ip4);
2473 /* Read data, if any */
2474 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2476 clib_warning ("rcvd data in syn-sent");
2477 error0 = tcp_segment_rcv (new_tc0, b0, &next0);
2478 if (error0 == TCP_ERROR_ACK_OK)
2479 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2480 tcp_maybe_inc_counter (syn_sent, error0, 1);
2484 tcp_make_ack (new_tc0, b0);
2485 next0 = tcp_next_output (new_tc0->c_is_ip4);
2490 b0->error = error0 ? node->errors[error0] : 0;
2492 ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2494 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2495 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2496 clib_memcpy (&t0->tcp_connection, tc0,
2497 sizeof (t0->tcp_connection));
2500 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2501 n_left_to_next, bi0, next0);
2504 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2507 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2509 tcp_inc_counter (syn_sent, TCP_ERROR_EVENT_FIFO_FULL, errors);
2510 return from_frame->n_vectors;
2514 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2515 vlib_frame_t * from_frame)
2517 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2521 tcp6_syn_sent_rcv (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, 0 /* is_ip4 */ );
2528 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2530 .function = tcp4_syn_sent,
2531 .name = "tcp4-syn-sent",
2532 /* Takes a vector of packets. */
2533 .vector_size = sizeof (u32),
2534 .n_errors = TCP_N_ERROR,
2535 .error_strings = tcp_error_strings,
2536 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2539 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2540 foreach_tcp_state_next
2543 .format_trace = format_tcp_rx_trace_short,
2547 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2550 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2552 .function = tcp6_syn_sent_rcv,
2553 .name = "tcp6-syn-sent",
2554 /* Takes a vector of packets. */
2555 .vector_size = sizeof (u32),
2556 .n_errors = TCP_N_ERROR,
2557 .error_strings = tcp_error_strings,
2558 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2561 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2562 foreach_tcp_state_next
2565 .format_trace = format_tcp_rx_trace_short,
2569 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2571 vlib_node_registration_t tcp4_rcv_process_node;
2572 vlib_node_registration_t tcp6_rcv_process_node;
2575 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2576 * as per RFC793 p. 64
2579 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2580 vlib_frame_t * from_frame, int is_ip4)
2582 u32 n_left_from, next_index, *from, *to_next, n_fins = 0;
2583 u32 my_thread_index = vm->thread_index, errors = 0;
2585 from = vlib_frame_vector_args (from_frame);
2586 n_left_from = from_frame->n_vectors;
2587 next_index = node->cached_next_index;
2589 while (n_left_from > 0)
2593 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2595 while (n_left_from > 0 && n_left_to_next > 0)
2599 tcp_header_t *tcp0 = 0;
2600 tcp_connection_t *tc0;
2601 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_NONE;
2609 n_left_to_next -= 1;
2611 b0 = vlib_get_buffer (vm, bi0);
2612 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2614 if (PREDICT_FALSE (tc0 == 0))
2616 error0 = TCP_ERROR_INVALID_CONNECTION;
2620 tcp0 = tcp_buffer_hdr (b0);
2621 is_fin0 = tcp_is_fin (tcp0);
2623 /* SYNs, FINs and data consume sequence numbers */
2624 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2625 + tcp_is_syn (tcp0) + is_fin0 + vnet_buffer (b0)->tcp.data_len;
2629 tcp_connection_t *tmp;
2630 tmp = tcp_lookup_connection (tc0->c_fib_index, b0,
2631 my_thread_index, is_ip4);
2632 if (tmp->state != tc0->state)
2634 clib_warning ("state changed");
2640 * Special treatment for CLOSED
2642 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2644 error0 = TCP_ERROR_CONNECTION_CLOSED;
2649 * For all other states (except LISTEN)
2652 /* 1-4: check SEQ, RST, SYN */
2653 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, tcp0,
2656 tcp_maybe_inc_counter (rcv_process, error0, 1);
2660 /* 5: check the ACK field */
2663 case TCP_STATE_SYN_RCVD:
2665 * If the segment acknowledgment is not acceptable, form a
2667 * <SEQ=SEG.ACK><CTL=RST>
2670 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2672 TCP_DBG ("connection not accepted");
2673 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2674 error0 = TCP_ERROR_ACK_INVALID;
2678 /* Update rtt and rto */
2679 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
2681 /* Switch state to ESTABLISHED */
2682 tc0->state = TCP_STATE_ESTABLISHED;
2683 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2685 /* Initialize session variables */
2686 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2687 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2688 << tc0->rcv_opts.wscale;
2689 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2690 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2692 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2693 tcp_retransmit_timer_reset (tc0);
2694 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2695 stream_session_accept_notify (&tc0->connection);
2696 error0 = TCP_ERROR_ACK_OK;
2698 case TCP_STATE_ESTABLISHED:
2699 /* We can get packets in established state here because they
2700 * were enqueued before state change */
2701 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2703 tcp_maybe_inc_counter (rcv_process, error0, 1);
2708 case TCP_STATE_FIN_WAIT_1:
2709 /* In addition to the processing for the ESTABLISHED state, if
2710 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2711 * continue processing in that state. */
2712 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2714 tcp_maybe_inc_counter (rcv_process, error0, 1);
2718 /* Still have to send the FIN */
2719 if (tc0->flags & TCP_CONN_FINPNDG)
2721 /* TX fifo finally drained */
2722 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2725 /* If FIN is ACKed */
2726 else if (tc0->snd_una == tc0->snd_una_max)
2728 tc0->state = TCP_STATE_FIN_WAIT_2;
2729 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2731 /* Stop all retransmit timers because we have nothing more
2732 * to send. Enable waitclose though because we're willing to
2733 * wait for peer's FIN but not indefinitely. */
2734 tcp_connection_timers_reset (tc0);
2735 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2738 case TCP_STATE_FIN_WAIT_2:
2739 /* In addition to the processing for the ESTABLISHED state, if
2740 * the retransmission queue is empty, the user's CLOSE can be
2741 * acknowledged ("ok") but do not delete the TCB. */
2742 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2744 tcp_maybe_inc_counter (rcv_process, error0, 1);
2748 case TCP_STATE_CLOSE_WAIT:
2749 /* Do the same processing as for the ESTABLISHED state. */
2750 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2752 tcp_maybe_inc_counter (rcv_process, error0, 1);
2755 if (tc0->flags & TCP_CONN_FINPNDG)
2757 /* TX fifo finally drained */
2758 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2761 tcp_connection_timers_reset (tc0);
2762 tc0->state = TCP_STATE_LAST_ACK;
2763 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2768 case TCP_STATE_CLOSING:
2769 /* In addition to the processing for the ESTABLISHED state, if
2770 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2771 * otherwise ignore the segment. */
2772 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2774 tcp_maybe_inc_counter (rcv_process, error0, 1);
2778 tc0->state = TCP_STATE_TIME_WAIT;
2779 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2780 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2784 case TCP_STATE_LAST_ACK:
2785 /* The only thing that [should] arrive in this state is an
2786 * acknowledgment of our FIN. If our FIN is now acknowledged,
2787 * delete the TCB, enter the CLOSED state, and return. */
2789 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2791 error0 = TCP_ERROR_ACK_INVALID;
2794 error0 = TCP_ERROR_ACK_OK;
2795 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2796 /* Apparently our ACK for the peer's FIN was lost */
2797 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2803 tc0->state = TCP_STATE_CLOSED;
2804 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2806 /* Don't free the connection from the data path since
2807 * we can't ensure that we have no packets already enqueued
2808 * to output. Rely instead on the waitclose timer */
2809 tcp_connection_timers_reset (tc0);
2810 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, 1);
2815 case TCP_STATE_TIME_WAIT:
2816 /* The only thing that can arrive in this state is a
2817 * retransmission of the remote FIN. Acknowledge it, and restart
2818 * the 2 MSL timeout. */
2820 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2822 tcp_maybe_inc_counter (rcv_process, error0, 1);
2826 tcp_make_ack (tc0, b0);
2827 next0 = tcp_next_output (is_ip4);
2828 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2836 /* 6: check the URG bit TODO */
2838 /* 7: process the segment text */
2841 case TCP_STATE_ESTABLISHED:
2842 case TCP_STATE_FIN_WAIT_1:
2843 case TCP_STATE_FIN_WAIT_2:
2844 if (vnet_buffer (b0)->tcp.data_len)
2846 error0 = tcp_segment_rcv (tc0, b0, &next0);
2847 tcp_maybe_inc_counter (rcv_process, error0, 1);
2852 case TCP_STATE_CLOSE_WAIT:
2853 case TCP_STATE_CLOSING:
2854 case TCP_STATE_LAST_ACK:
2855 case TCP_STATE_TIME_WAIT:
2856 /* This should not occur, since a FIN has been received from the
2857 * remote side. Ignore the segment text. */
2861 /* 8: check the FIN bit */
2867 case TCP_STATE_ESTABLISHED:
2868 case TCP_STATE_SYN_RCVD:
2869 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2870 tcp_connection_timers_reset (tc0);
2871 tcp_make_fin (tc0, b0);
2873 tc0->snd_una_max = tc0->snd_nxt;
2874 tcp_retransmit_timer_set (tc0);
2875 next0 = tcp_next_output (tc0->c_is_ip4);
2876 stream_session_disconnect_notify (&tc0->connection);
2877 tc0->state = TCP_STATE_CLOSE_WAIT;
2878 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2880 case TCP_STATE_CLOSE_WAIT:
2881 case TCP_STATE_CLOSING:
2882 case TCP_STATE_LAST_ACK:
2885 case TCP_STATE_FIN_WAIT_1:
2886 tc0->state = TCP_STATE_CLOSING;
2887 tcp_make_ack (tc0, b0);
2888 next0 = tcp_next_output (is_ip4);
2889 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2890 /* Wait for ACK but not forever */
2891 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2893 case TCP_STATE_FIN_WAIT_2:
2894 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2895 tc0->state = TCP_STATE_TIME_WAIT;
2896 tcp_connection_timers_reset (tc0);
2897 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2898 tcp_make_ack (tc0, b0);
2899 next0 = tcp_next_output (is_ip4);
2900 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2902 case TCP_STATE_TIME_WAIT:
2903 /* Remain in the TIME-WAIT state. Restart the time-wait
2906 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2909 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2913 b0->error = error0 ? node->errors[error0] : 0;
2915 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2917 tcp_rx_trace_t *t0 =
2918 vlib_add_trace (vm, node, b0, sizeof (*t0));
2919 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2922 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2923 n_left_to_next, bi0, next0);
2926 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2929 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2931 tcp_inc_counter (rcv_process, TCP_ERROR_EVENT_FIFO_FULL, errors);
2932 tcp_inc_counter (rcv_process, TCP_ERROR_FIN_RCVD, n_fins);
2933 return from_frame->n_vectors;
2937 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2938 vlib_frame_t * from_frame)
2940 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2944 tcp6_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, 0 /* is_ip4 */ );
2951 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2953 .function = tcp4_rcv_process,
2954 .name = "tcp4-rcv-process",
2955 /* Takes a vector of packets. */
2956 .vector_size = sizeof (u32),
2957 .n_errors = TCP_N_ERROR,
2958 .error_strings = tcp_error_strings,
2959 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2962 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2963 foreach_tcp_state_next
2966 .format_trace = format_tcp_rx_trace_short,
2970 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2973 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2975 .function = tcp6_rcv_process,
2976 .name = "tcp6-rcv-process",
2977 /* Takes a vector of packets. */
2978 .vector_size = sizeof (u32),
2979 .n_errors = TCP_N_ERROR,
2980 .error_strings = tcp_error_strings,
2981 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2984 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2985 foreach_tcp_state_next
2988 .format_trace = format_tcp_rx_trace_short,
2992 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2994 vlib_node_registration_t tcp4_listen_node;
2995 vlib_node_registration_t tcp6_listen_node;
2998 * LISTEN state processing as per RFC 793 p. 65
3001 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3002 vlib_frame_t * from_frame, int is_ip4)
3004 u32 n_left_from, next_index, *from, *to_next, n_syns = 0;
3005 u32 my_thread_index = vm->thread_index;
3007 from = vlib_frame_vector_args (from_frame);
3008 n_left_from = from_frame->n_vectors;
3010 next_index = node->cached_next_index;
3012 while (n_left_from > 0)
3016 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
3018 while (n_left_from > 0 && n_left_to_next > 0)
3023 tcp_header_t *th0 = 0;
3024 tcp_connection_t *lc0;
3027 tcp_connection_t *child0;
3028 u32 error0 = TCP_ERROR_NONE, next0 = tcp_next_drop (is_ip4);
3035 n_left_to_next -= 1;
3037 b0 = vlib_get_buffer (vm, bi0);
3038 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3042 ip40 = vlib_buffer_get_current (b0);
3043 th0 = ip4_next_header (ip40);
3047 ip60 = vlib_buffer_get_current (b0);
3048 th0 = ip6_next_header (ip60);
3051 /* Create child session. For syn-flood protection use filter */
3053 /* 1. first check for an RST: handled in dispatch */
3054 /* if (tcp_rst (th0))
3057 /* 2. second check for an ACK: handled in dispatch */
3058 /* if (tcp_ack (th0))
3060 tcp_send_reset (b0, is_ip4);
3064 /* 3. check for a SYN (did that already) */
3066 /* Make sure connection wasn't just created */
3067 child0 = tcp_lookup_connection (lc0->c_fib_index, b0,
3068 my_thread_index, is_ip4);
3069 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3071 error0 = TCP_ERROR_CREATE_EXISTS;
3075 /* Create child session and send SYN-ACK */
3076 child0 = tcp_connection_new (my_thread_index);
3077 child0->c_lcl_port = th0->dst_port;
3078 child0->c_rmt_port = th0->src_port;
3079 child0->c_is_ip4 = is_ip4;
3080 child0->state = TCP_STATE_SYN_RCVD;
3081 child0->c_fib_index = lc0->c_fib_index;
3085 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3086 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3090 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
3091 sizeof (ip6_address_t));
3092 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
3093 sizeof (ip6_address_t));
3096 if (tcp_options_parse (th0, &child0->rcv_opts))
3098 clib_warning ("options parse fail");
3102 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3103 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3104 child0->rcv_las = child0->rcv_nxt;
3105 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3107 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3108 * segments are used to initialize PAWS. */
3109 if (tcp_opts_tstamp (&child0->rcv_opts))
3111 child0->tsval_recent = child0->rcv_opts.tsval;
3112 child0->tsval_recent_age = tcp_time_now ();
3115 if (tcp_opts_wscale (&child0->rcv_opts))
3116 child0->snd_wscale = child0->rcv_opts.wscale;
3118 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3119 << child0->snd_wscale;
3120 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3121 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3123 tcp_connection_init_vars (child0);
3124 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
3126 if (stream_session_accept (&child0->connection, lc0->c_s_index,
3129 clib_warning ("session accept fail");
3130 tcp_connection_cleanup (child0);
3131 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3135 /* Reuse buffer to make syn-ack and send */
3136 tcp_make_synack (child0, b0);
3137 next0 = tcp_next_output (is_ip4);
3138 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
3141 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3143 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3144 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3145 clib_memcpy (&t0->tcp_connection, lc0,
3146 sizeof (t0->tcp_connection));
3149 n_syns += (error0 == TCP_ERROR_NONE);
3150 b0->error = node->errors[error0];
3152 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
3153 n_left_to_next, bi0, next0);
3156 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
3159 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3160 return from_frame->n_vectors;
3164 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3165 vlib_frame_t * from_frame)
3167 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3171 tcp6_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, 0 /* is_ip4 */ );
3178 VLIB_REGISTER_NODE (tcp4_listen_node) =
3180 .function = tcp4_listen,
3181 .name = "tcp4-listen",
3182 /* Takes a vector of packets. */
3183 .vector_size = sizeof (u32),
3184 .n_errors = TCP_N_ERROR,
3185 .error_strings = tcp_error_strings,
3186 .n_next_nodes = TCP_LISTEN_N_NEXT,
3189 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3190 foreach_tcp_state_next
3193 .format_trace = format_tcp_rx_trace_short,
3197 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
3200 VLIB_REGISTER_NODE (tcp6_listen_node) =
3202 .function = tcp6_listen,
3203 .name = "tcp6-listen",
3204 /* Takes a vector of packets. */
3205 .vector_size = sizeof (u32),
3206 .n_errors = TCP_N_ERROR,
3207 .error_strings = tcp_error_strings,
3208 .n_next_nodes = TCP_LISTEN_N_NEXT,
3211 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3212 foreach_tcp_state_next
3215 .format_trace = format_tcp_rx_trace_short,
3219 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
3221 vlib_node_registration_t tcp4_input_node;
3222 vlib_node_registration_t tcp6_input_node;
3224 typedef enum _tcp_input_next
3226 TCP_INPUT_NEXT_DROP,
3227 TCP_INPUT_NEXT_LISTEN,
3228 TCP_INPUT_NEXT_RCV_PROCESS,
3229 TCP_INPUT_NEXT_SYN_SENT,
3230 TCP_INPUT_NEXT_ESTABLISHED,
3231 TCP_INPUT_NEXT_RESET,
3232 TCP_INPUT_NEXT_PUNT,
3236 #define foreach_tcp4_input_next \
3237 _ (DROP, "ip4-drop") \
3238 _ (LISTEN, "tcp4-listen") \
3239 _ (RCV_PROCESS, "tcp4-rcv-process") \
3240 _ (SYN_SENT, "tcp4-syn-sent") \
3241 _ (ESTABLISHED, "tcp4-established") \
3242 _ (RESET, "tcp4-reset") \
3243 _ (PUNT, "ip4-punt")
3245 #define foreach_tcp6_input_next \
3246 _ (DROP, "ip6-drop") \
3247 _ (LISTEN, "tcp6-listen") \
3248 _ (RCV_PROCESS, "tcp6-rcv-process") \
3249 _ (SYN_SENT, "tcp6-syn-sent") \
3250 _ (ESTABLISHED, "tcp6-established") \
3251 _ (RESET, "tcp6-reset") \
3252 _ (PUNT, "ip6-punt")
3254 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3257 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3258 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3260 tcp_connection_t *tc;
3265 for (i = 0; i < n_bufs; i++)
3267 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3269 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3270 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3272 tcp = vlib_buffer_get_current (bs[i]);
3273 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3279 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3281 if (*error == TCP_ERROR_FILTERED)
3283 *next = TCP_INPUT_NEXT_DROP;
3285 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3287 *next = TCP_INPUT_NEXT_PUNT;
3288 *error = TCP_ERROR_PUNT;
3292 *next = TCP_INPUT_NEXT_RESET;
3293 *error = TCP_ERROR_NO_LISTENER;
3297 static inline tcp_connection_t *
3298 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3301 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3302 int n_advance_bytes, n_data_bytes;
3303 transport_connection_t *tc;
3309 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3310 tcp = ip4_next_header (ip4);
3311 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3312 n_advance_bytes = (ip4_header_bytes (ip4) + tcp_header_bytes (tcp));
3313 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3315 /* Length check. Checksum computed by ipx_local no need to compute again */
3316 if (PREDICT_FALSE (n_advance_bytes < 0))
3318 *error = TCP_ERROR_LENGTH;
3322 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3323 &ip4->src_address, tcp->dst_port,
3324 tcp->src_port, TRANSPORT_PROTO_TCP,
3325 thread_index, &is_filtered);
3329 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3330 tcp = ip6_next_header (ip6);
3331 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3332 n_advance_bytes = tcp_header_bytes (tcp);
3333 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3335 n_advance_bytes += sizeof (ip6[0]);
3337 if (PREDICT_FALSE (n_advance_bytes < 0))
3339 *error = TCP_ERROR_LENGTH;
3343 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3344 &ip6->src_address, tcp->dst_port,
3345 tcp->src_port, TRANSPORT_PROTO_TCP,
3346 thread_index, &is_filtered);
3349 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3350 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3351 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3352 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3353 vnet_buffer (b)->tcp.flags = 0;
3355 *error = is_filtered ? TCP_ERROR_FILTERED : *error;
3357 return tcp_get_connection_from_transport (tc);
3361 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3362 vlib_buffer_t * b, u16 * next, u32 * error)
3367 tcp = tcp_buffer_hdr (b);
3368 flags = tcp->flags & filter_flags;
3369 *next = tm->dispatch_table[tc->state][flags].next;
3370 *error = tm->dispatch_table[tc->state][flags].error;
3372 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3373 || *next == TCP_INPUT_NEXT_RESET))
3375 /* Overload tcp flags to store state */
3376 tcp_state_t state = tc->state;
3377 vnet_buffer (b)->tcp.flags = tc->state;
3379 if (*error == TCP_ERROR_DISPATCH)
3380 clib_warning ("disp error state %U flags %U", format_tcp_state,
3381 state, format_tcp_flags, (int) flags);
3386 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3387 vlib_frame_t * frame, int is_ip4)
3389 u32 n_left_from, *from, thread_index = vm->thread_index;
3390 tcp_main_t *tm = vnet_get_tcp_main ();
3391 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3392 u16 nexts[VLIB_FRAME_SIZE], *next;
3394 tcp_set_time_now (tcp_get_worker (thread_index));
3396 from = vlib_frame_vector_args (frame);
3397 n_left_from = frame->n_vectors;
3398 vlib_get_buffers (vm, from, bufs, n_left_from);
3403 while (n_left_from >= 4)
3405 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3406 tcp_connection_t *tc0, *tc1;
3409 vlib_prefetch_buffer_header (b[2], STORE);
3410 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3412 vlib_prefetch_buffer_header (b[3], STORE);
3413 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3416 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3418 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3419 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4);
3421 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3423 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3424 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3426 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3427 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3429 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3430 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3434 if (PREDICT_TRUE (tc0 != 0))
3436 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3437 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3438 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3441 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3443 if (PREDICT_TRUE (tc1 != 0))
3445 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3446 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3447 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3450 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3457 while (n_left_from > 0)
3459 tcp_connection_t *tc0;
3460 u32 error0 = TCP_ERROR_NO_LISTENER;
3462 if (n_left_from > 1)
3464 vlib_prefetch_buffer_header (b[1], STORE);
3465 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3468 next[0] = TCP_INPUT_NEXT_DROP;
3469 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3470 if (PREDICT_TRUE (tc0 != 0))
3472 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3473 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3474 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3477 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3484 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3485 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3487 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3488 return frame->n_vectors;
3492 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3493 vlib_frame_t * from_frame)
3495 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3499 tcp6_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, 0 /* is_ip4 */ );
3506 VLIB_REGISTER_NODE (tcp4_input_node) =
3508 .function = tcp4_input,
3509 .name = "tcp4-input",
3510 /* Takes a vector of packets. */
3511 .vector_size = sizeof (u32),
3512 .n_errors = TCP_N_ERROR,
3513 .error_strings = tcp_error_strings,
3514 .n_next_nodes = TCP_INPUT_N_NEXT,
3517 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3518 foreach_tcp4_input_next
3521 .format_buffer = format_tcp_header,
3522 .format_trace = format_tcp_rx_trace,
3526 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3529 VLIB_REGISTER_NODE (tcp6_input_node) =
3531 .function = tcp6_input,
3532 .name = "tcp6-input",
3533 /* Takes a vector of packets. */
3534 .vector_size = sizeof (u32),
3535 .n_errors = TCP_N_ERROR,
3536 .error_strings = tcp_error_strings,
3537 .n_next_nodes = TCP_INPUT_N_NEXT,
3540 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3541 foreach_tcp6_input_next
3544 .format_buffer = format_tcp_header,
3545 .format_trace = format_tcp_rx_trace,
3549 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3552 tcp_dispatch_table_init (tcp_main_t * tm)
3555 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3556 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3558 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3559 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3562 #define _(t,f,n,e) \
3564 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3565 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3568 /* SYNs for new connections -> tcp-listen. */
3569 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3570 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3571 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_RST_RCVD);
3572 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3574 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3575 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3576 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3577 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3579 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3580 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3582 /* SYN-ACK for a SYN */
3583 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3585 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3586 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3587 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3589 /* ACK for for established connection -> tcp-established. */
3590 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3591 /* FIN for for established connection -> tcp-established. */
3592 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3593 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3595 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3596 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3598 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3599 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3601 /* ACK or FIN-ACK to our FIN */
3602 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3603 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3605 /* FIN in reply to our FIN from the other side */
3606 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3607 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3608 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3609 /* FIN confirming that the peer (app) has closed */
3610 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3611 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3612 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3614 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3615 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3617 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3618 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3619 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3621 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3622 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3623 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3624 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3626 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3627 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3628 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3629 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3630 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3631 TCP_ERROR_CONNECTION_CLOSED);
3635 static clib_error_t *
3636 tcp_input_init (vlib_main_t * vm)
3638 clib_error_t *error = 0;
3639 tcp_main_t *tm = vnet_get_tcp_main ();
3641 if ((error = vlib_call_init_function (vm, tcp_init)))
3644 /* Initialize dispatch table. */
3645 tcp_dispatch_table_init (tm);
3650 VLIB_INIT_FUNCTION (tcp_input_init);
3653 * fd.io coding-style-patch-verification: ON
3656 * eval: (c-set-style "gnu")