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 (tcp_worker_ctx_t * wrk, tcp_connection_t * tc0,
276 vlib_buffer_t * b0, tcp_header_t * th0, u32 * error0)
278 /* We could get a burst of RSTs interleaved with acks */
279 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
281 tcp_send_reset (tc0);
282 *error0 = TCP_ERROR_CONNECTION_CLOSED;
286 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
288 *error0 = TCP_ERROR_SEGMENT_INVALID;
292 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts)))
294 clib_warning ("options parse error");
295 *error0 = TCP_ERROR_OPTIONS;
299 if (PREDICT_FALSE (tcp_segment_check_paws (tc0)))
301 *error0 = TCP_ERROR_PAWS;
303 clib_warning ("paws failed\n%U", format_tcp_connection, tc0, 2);
304 TCP_EVT_DBG (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
305 vnet_buffer (b0)->tcp.seq_end);
307 /* If it just so happens that a segment updates tsval_recent for a
308 * segment over 24 days old, invalidate tsval_recent. */
309 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
310 tcp_time_now_w_thread (tc0->c_thread_index)))
312 /* Age isn't reset until we get a valid tsval (bsd inspired) */
313 tc0->tsval_recent = 0;
314 clib_warning ("paws failed - really old segment. REALLY?");
318 /* Drop after ack if not rst */
321 tcp_program_ack (wrk, tc0);
322 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
328 /* 1st: check sequence number */
329 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
330 vnet_buffer (b0)->tcp.seq_end))
332 *error0 = TCP_ERROR_RCV_WND;
333 /* If our window is 0 and the packet is in sequence, let it pass
334 * through for ack processing. It should be dropped later. */
335 if (!(tc0->rcv_wnd == 0
336 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number))
338 /* If not RST, send dup ack */
341 tcp_program_dupack (wrk, tc0);
342 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
348 /* 2nd: check the RST bit */
349 if (PREDICT_FALSE (tcp_rst (th0)))
351 tcp_connection_reset (tc0);
352 *error0 = TCP_ERROR_RST_RCVD;
356 /* 3rd: check security and precedence (skip) */
358 /* 4th: check the SYN bit */
359 if (PREDICT_FALSE (tcp_syn (th0)))
361 /* TODO implement RFC 5961 */
362 if (tc0->state == TCP_STATE_SYN_RCVD)
364 tcp_send_synack (tc0);
365 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0, 0);
369 tcp_program_ack (wrk, tc0);
370 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, tc0);
375 /* If segment in window, save timestamp */
376 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
377 vnet_buffer (b0)->tcp.seq_end);
385 tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0)
387 /* SND.UNA =< SEG.ACK =< SND.NXT */
388 return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number)
389 && seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt));
393 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
395 * Note that although the original article, srtt and rttvar are scaled
396 * to minimize round-off errors, here we don't. Instead, we rely on
397 * better precision time measurements.
399 * TODO support us rtt resolution
402 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
408 err = mrtt - tc->srtt;
410 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
411 * The increase should be bound */
412 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
413 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
414 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
418 /* First measurement. */
420 tc->rttvar = mrtt >> 1;
425 tcp_update_rto (tcp_connection_t * tc)
427 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
428 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
432 * Update RTT estimate and RTO timer
434 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
435 * timing. Middle boxes are known to fiddle with TCP options so we
436 * should give higher priority to ACK timing.
438 * This should be called only if previously sent bytes have been acked.
440 * return 1 if valid rtt 0 otherwise
443 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
447 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
448 * RTT because they're ambiguous. */
449 if (tcp_in_cong_recovery (tc) || tc->sack_sb.sacked_bytes)
451 if (tcp_in_recovery (tc))
456 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
458 f64 sample = tcp_time_now_us (tc->c_thread_index) - tc->rtt_ts;
459 tc->mrtt_us = tc->mrtt_us + (sample - tc->mrtt_us) * 0.125;
460 mrtt = clib_max ((u32) (sample * THZ), 1);
461 /* Allow measuring of a new RTT */
464 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
465 * snd_una, i.e., the left side of the send window:
466 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
467 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
469 u32 now = tcp_time_now_w_thread (tc->c_thread_index);
470 mrtt = clib_max (now - tc->rcv_opts.tsecr, 1);
473 /* Ignore dubious measurements */
474 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
477 tcp_estimate_rtt (tc, mrtt);
481 /* If we got here something must've been ACKed so make sure boff is 0,
482 * even if mrtt is not valid since we update the rto lower */
490 tcp_estimate_initial_rtt (tcp_connection_t * tc)
492 u8 thread_index = vlib_num_workers ()? 1 : 0;
497 tc->mrtt_us = tcp_time_now_us (thread_index) - tc->rtt_ts;
498 mrtt = clib_max ((u32) (tc->mrtt_us * THZ), 1);
503 mrtt = tcp_time_now_w_thread (thread_index) - tc->rcv_opts.tsecr;
504 tc->mrtt_us = (f64) mrtt *TCP_TICK;
508 if (mrtt > 0 && mrtt < TCP_RTT_MAX)
509 tcp_estimate_rtt (tc, mrtt);
513 * Dequeue bytes for connections that have received acks in last burst
516 tcp_handle_postponed_dequeues (tcp_worker_ctx_t * wrk)
518 u32 thread_index = wrk->vm->thread_index;
519 u32 *pending_deq_acked;
520 tcp_connection_t *tc;
523 if (!vec_len (wrk->pending_deq_acked))
526 pending_deq_acked = wrk->pending_deq_acked;
527 for (i = 0; i < vec_len (pending_deq_acked); i++)
529 tc = tcp_connection_get (pending_deq_acked[i], thread_index);
530 tc->flags &= ~TCP_CONN_DEQ_PENDING;
532 if (PREDICT_FALSE (!tc->burst_acked))
535 /* Dequeue the newly ACKed bytes */
536 stream_session_dequeue_drop (&tc->connection, tc->burst_acked);
538 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
540 /* If everything has been acked, stop retransmit timer
541 * otherwise update. */
542 tcp_retransmit_timer_update (tc);
544 /* If not congested, update pacer based on our new
546 if (!tcp_in_fastrecovery (tc))
547 tcp_connection_tx_pacer_update (tc);
549 _vec_len (wrk->pending_deq_acked) = 0;
553 tcp_program_dequeue (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
555 if (!(tc->flags & TCP_CONN_DEQ_PENDING))
557 vec_add1 (wrk->pending_deq_acked, tc->c_c_index);
558 tc->flags |= TCP_CONN_DEQ_PENDING;
560 tc->burst_acked += tc->bytes_acked + tc->sack_sb.snd_una_adv;
564 * Check if duplicate ack as per RFC5681 Sec. 2
567 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
570 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
571 && seq_gt (tc->snd_una_max, tc->snd_una)
572 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
573 && (prev_snd_wnd == tc->snd_wnd));
577 * Checks if ack is a congestion control event.
580 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
581 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
583 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
584 * defined to be 'duplicate' */
585 *is_dack = tc->sack_sb.last_sacked_bytes
586 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
588 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
592 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
594 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
595 return hole - sb->holes;
599 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
601 return hole->end - hole->start;
604 sack_scoreboard_hole_t *
605 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
607 if (index != TCP_INVALID_SACK_HOLE_INDEX)
608 return pool_elt_at_index (sb->holes, index);
612 sack_scoreboard_hole_t *
613 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
615 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
616 return pool_elt_at_index (sb->holes, hole->next);
620 sack_scoreboard_hole_t *
621 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
623 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
624 return pool_elt_at_index (sb->holes, hole->prev);
628 sack_scoreboard_hole_t *
629 scoreboard_first_hole (sack_scoreboard_t * sb)
631 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
632 return pool_elt_at_index (sb->holes, sb->head);
636 sack_scoreboard_hole_t *
637 scoreboard_last_hole (sack_scoreboard_t * sb)
639 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
640 return pool_elt_at_index (sb->holes, sb->tail);
645 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
647 sack_scoreboard_hole_t *next, *prev;
649 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
651 next = pool_elt_at_index (sb->holes, hole->next);
652 next->prev = hole->prev;
656 sb->tail = hole->prev;
659 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
661 prev = pool_elt_at_index (sb->holes, hole->prev);
662 prev->next = hole->next;
666 sb->head = hole->next;
669 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
670 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
672 /* Poison the entry */
674 clib_memset (hole, 0xfe, sizeof (*hole));
676 pool_put (sb->holes, hole);
679 static sack_scoreboard_hole_t *
680 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
683 sack_scoreboard_hole_t *hole, *next, *prev;
686 pool_get (sb->holes, hole);
687 clib_memset (hole, 0, sizeof (*hole));
691 hole_index = scoreboard_hole_index (sb, hole);
693 prev = scoreboard_get_hole (sb, prev_index);
696 hole->prev = prev_index;
697 hole->next = prev->next;
699 if ((next = scoreboard_next_hole (sb, hole)))
700 next->prev = hole_index;
702 sb->tail = hole_index;
704 prev->next = hole_index;
708 sb->head = hole_index;
709 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
710 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
717 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
719 sack_scoreboard_hole_t *left, *right;
720 u32 bytes = 0, blks = 0;
723 sb->sacked_bytes = 0;
724 left = scoreboard_last_hole (sb);
728 if (seq_gt (sb->high_sacked, left->end))
730 bytes = sb->high_sacked - left->end;
734 while ((right = left)
735 && bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
736 && blks < TCP_DUPACK_THRESHOLD
737 /* left not updated if above conditions fail */
738 && (left = scoreboard_prev_hole (sb, right)))
740 bytes += right->start - left->end;
744 /* left is first lost */
749 sb->lost_bytes += scoreboard_hole_bytes (right);
751 left = scoreboard_prev_hole (sb, right);
753 bytes += right->start - left->end;
755 while ((right = left));
758 sb->sacked_bytes = bytes;
762 * Figure out the next hole to retransmit
764 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
766 sack_scoreboard_hole_t *
767 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
768 sack_scoreboard_hole_t * start,
769 u8 have_unsent, u8 * can_rescue, u8 * snd_limited)
771 sack_scoreboard_hole_t *hole = 0;
773 hole = start ? start : scoreboard_first_hole (sb);
774 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
775 hole = scoreboard_next_hole (sb, hole);
777 /* Nothing, return */
780 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
784 /* Rule (1): if higher than rxt, less than high_sacked and lost */
785 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
787 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
791 /* Rule (2): available unsent data */
794 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
797 /* Rule (3): if hole not lost */
798 else if (seq_lt (hole->start, sb->high_sacked))
801 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
803 /* Rule (4): if hole beyond high_sacked */
806 ASSERT (seq_geq (hole->start, sb->high_sacked));
809 /* HighRxt MUST NOT be updated */
814 if (hole && seq_lt (sb->high_rxt, hole->start))
815 sb->high_rxt = hole->start;
821 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 snd_una)
823 sack_scoreboard_hole_t *hole;
824 hole = scoreboard_first_hole (sb);
827 snd_una = seq_gt (snd_una, hole->start) ? snd_una : hole->start;
828 sb->cur_rxt_hole = sb->head;
830 sb->high_rxt = snd_una;
831 sb->rescue_rxt = snd_una - 1;
835 scoreboard_init (sack_scoreboard_t * sb)
837 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
838 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
839 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
843 scoreboard_clear (sack_scoreboard_t * sb)
845 sack_scoreboard_hole_t *hole;
846 while ((hole = scoreboard_first_hole (sb)))
848 scoreboard_remove_hole (sb, hole);
850 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
851 ASSERT (pool_elts (sb->holes) == 0);
852 sb->sacked_bytes = 0;
853 sb->last_sacked_bytes = 0;
854 sb->last_bytes_delivered = 0;
859 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
863 * Test that scoreboard is sane after recovery
865 * Returns 1 if scoreboard is empty or if first hole beyond
869 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
871 sack_scoreboard_hole_t *hole;
872 hole = scoreboard_first_hole (&tc->sack_sb);
873 return (!hole || (seq_geq (hole->start, tc->snd_una)
874 && seq_lt (hole->end, tc->snd_una_max)));
878 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
880 sack_scoreboard_t *sb = &tc->sack_sb;
881 sack_block_t *blk, tmp;
882 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
883 u32 blk_index = 0, old_sacked_bytes, hole_index;
886 sb->last_sacked_bytes = 0;
887 sb->last_bytes_delivered = 0;
890 if (!tcp_opts_sack (&tc->rcv_opts)
891 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
894 old_sacked_bytes = sb->sacked_bytes;
896 /* Remove invalid blocks */
897 blk = tc->rcv_opts.sacks;
898 while (blk < vec_end (tc->rcv_opts.sacks))
900 if (seq_lt (blk->start, blk->end)
901 && seq_gt (blk->start, tc->snd_una)
902 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_una_max))
907 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
910 /* Add block for cumulative ack */
911 if (seq_gt (ack, tc->snd_una))
913 tmp.start = tc->snd_una;
915 vec_add1 (tc->rcv_opts.sacks, tmp);
918 if (vec_len (tc->rcv_opts.sacks) == 0)
921 tcp_scoreboard_trace_add (tc, ack);
923 /* Make sure blocks are ordered */
924 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
925 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
926 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
928 tmp = tc->rcv_opts.sacks[i];
929 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
930 tc->rcv_opts.sacks[j] = tmp;
933 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
935 /* If no holes, insert the first that covers all outstanding bytes */
936 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
937 tc->snd_una, tc->snd_una_max);
938 sb->tail = scoreboard_hole_index (sb, last_hole);
939 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
940 sb->high_sacked = tmp.end;
944 /* If we have holes but snd_una_max is beyond the last hole, update
946 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
947 last_hole = scoreboard_last_hole (sb);
948 if (seq_gt (tc->snd_una_max, last_hole->end))
950 if (seq_geq (last_hole->start, sb->high_sacked))
952 last_hole->end = tc->snd_una_max;
954 /* New hole after high sacked block */
955 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
957 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
961 /* Keep track of max byte sacked for when the last hole
963 if (seq_gt (tmp.end, sb->high_sacked))
964 sb->high_sacked = tmp.end;
967 /* Walk the holes with the SACK blocks */
968 hole = pool_elt_at_index (sb->holes, sb->head);
969 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
971 blk = &tc->rcv_opts.sacks[blk_index];
972 if (seq_leq (blk->start, hole->start))
974 /* Block covers hole. Remove hole */
975 if (seq_geq (blk->end, hole->end))
977 next_hole = scoreboard_next_hole (sb, hole);
979 /* Byte accounting: snd_una needs to be advanced */
984 if (seq_lt (ack, next_hole->start))
985 sb->snd_una_adv = next_hole->start - ack;
986 sb->last_bytes_delivered +=
987 next_hole->start - hole->end;
991 ASSERT (seq_geq (sb->high_sacked, ack));
992 sb->snd_una_adv = sb->high_sacked - ack;
993 sb->last_bytes_delivered += sb->high_sacked - hole->end;
997 scoreboard_remove_hole (sb, hole);
1000 /* Partial 'head' overlap */
1003 if (seq_gt (blk->end, hole->start))
1005 hole->start = blk->end;
1012 /* Hole must be split */
1013 if (seq_lt (blk->end, hole->end))
1015 hole_index = scoreboard_hole_index (sb, hole);
1016 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
1019 /* Pool might've moved */
1020 hole = scoreboard_get_hole (sb, hole_index);
1021 hole->end = blk->start;
1023 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
1025 else if (seq_lt (blk->start, hole->end))
1027 hole->end = blk->start;
1029 hole = scoreboard_next_hole (sb, hole);
1033 if (pool_elts (sb->holes) == 1)
1035 hole = scoreboard_first_hole (sb);
1036 if (hole->start == ack + sb->snd_una_adv
1037 && hole->end == tc->snd_una_max)
1038 scoreboard_remove_hole (sb, hole);
1041 scoreboard_update_bytes (tc, sb);
1042 sb->last_sacked_bytes = sb->sacked_bytes
1043 - (old_sacked_bytes - sb->last_bytes_delivered);
1044 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
1045 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
1046 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
1047 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
1048 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1049 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1050 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
1051 TCP_EVT_DBG (TCP_EVT_CC_SCOREBOARD, tc);
1055 * Try to update snd_wnd based on feedback received from peer.
1057 * If successful, and new window is 'effectively' 0, activate persist
1061 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1063 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1064 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1065 if (seq_lt (tc->snd_wl1, seq)
1066 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1068 tc->snd_wnd = snd_wnd;
1071 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
1073 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
1075 /* Set persist timer if not set and we just got 0 wnd */
1076 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1077 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1078 tcp_persist_timer_set (tc);
1082 tcp_persist_timer_reset (tc);
1083 if (PREDICT_FALSE (!tcp_in_recovery (tc) && tc->rto_boff > 0))
1086 tcp_update_rto (tc);
1093 * Init loss recovery/fast recovery.
1095 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1096 * updated in @ref tcp_cc_handle_event after fast retransmit
1099 tcp_cc_init_congestion (tcp_connection_t * tc)
1101 tcp_fastrecovery_on (tc);
1102 tc->snd_congestion = tc->snd_una_max;
1103 tc->cwnd_acc_bytes = 0;
1104 tc->snd_rxt_bytes = 0;
1105 tc->prev_ssthresh = tc->ssthresh;
1106 tc->prev_cwnd = tc->cwnd;
1107 tc->cc_algo->congestion (tc);
1108 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
1112 tcp_cc_recovery_exit (tcp_connection_t * tc)
1115 tcp_update_rto (tc);
1117 tc->snd_nxt = tc->snd_una_max;
1119 tcp_recovery_off (tc);
1120 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1124 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
1126 tc->cc_algo->recovered (tc);
1127 tc->snd_rxt_bytes = 0;
1128 tc->rcv_dupacks = 0;
1129 tc->snd_nxt = tc->snd_una_max;
1130 tc->snd_rxt_bytes = 0;
1133 tcp_fastrecovery_off (tc);
1134 tcp_fastrecovery_first_off (tc);
1136 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1140 tcp_cc_congestion_undo (tcp_connection_t * tc)
1142 tc->cwnd = tc->prev_cwnd;
1143 tc->ssthresh = tc->prev_ssthresh;
1144 tc->snd_nxt = tc->snd_una_max;
1145 tc->rcv_dupacks = 0;
1146 if (tcp_in_recovery (tc))
1147 tcp_cc_recovery_exit (tc);
1148 else if (tcp_in_fastrecovery (tc))
1149 tcp_cc_fastrecovery_exit (tc);
1150 ASSERT (tc->rto_boff == 0);
1151 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
1155 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1157 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1159 && tcp_opts_tstamp (&tc->rcv_opts)
1160 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1164 tcp_cc_is_spurious_fast_rxt (tcp_connection_t * tc)
1166 return (tcp_in_fastrecovery (tc)
1167 && tc->cwnd > tc->ssthresh + 3 * tc->snd_mss);
1171 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1173 return (tcp_cc_is_spurious_timeout_rxt (tc)
1174 || tcp_cc_is_spurious_fast_rxt (tc));
1178 tcp_cc_recover (tcp_connection_t * tc)
1180 ASSERT (tcp_in_cong_recovery (tc));
1181 if (tcp_cc_is_spurious_retransmit (tc))
1183 tcp_cc_congestion_undo (tc);
1187 if (tcp_in_recovery (tc))
1188 tcp_cc_recovery_exit (tc);
1189 else if (tcp_in_fastrecovery (tc))
1190 tcp_cc_fastrecovery_exit (tc);
1192 ASSERT (tc->rto_boff == 0);
1193 ASSERT (!tcp_in_cong_recovery (tc));
1194 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1199 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
1201 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1203 /* Congestion avoidance */
1204 tcp_cc_rcv_ack (tc);
1206 /* If a cumulative ack, make sure dupacks is 0 */
1207 tc->rcv_dupacks = 0;
1209 /* When dupacks hits the threshold we only enter fast retransmit if
1210 * cumulative ack covers more than snd_congestion. Should snd_una
1211 * wrap this test may fail under otherwise valid circumstances.
1212 * Therefore, proactively update snd_congestion when wrap detected. */
1214 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1215 && seq_gt (tc->snd_congestion, tc->snd_una)))
1216 tc->snd_congestion = tc->snd_una - 1;
1220 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1222 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1226 tcp_should_fastrecover (tcp_connection_t * tc)
1228 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1229 || tcp_should_fastrecover_sack (tc));
1233 tcp_program_fastretransmit (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1235 if (!(tc->flags & TCP_CONN_FRXT_PENDING))
1237 vec_add1 (wrk->pending_fast_rxt, tc->c_c_index);
1238 tc->flags |= TCP_CONN_FRXT_PENDING;
1243 tcp_do_fastretransmits (tcp_worker_ctx_t * wrk)
1245 u32 *ongoing_fast_rxt, burst_bytes, sent_bytes, thread_index;
1246 u32 max_burst_size, burst_size, n_segs = 0, n_segs_now;
1247 tcp_connection_t *tc;
1251 if (vec_len (wrk->pending_fast_rxt) == 0
1252 && vec_len (wrk->postponed_fast_rxt) == 0)
1255 thread_index = wrk->vm->thread_index;
1256 last_cpu_time = wrk->vm->clib_time.last_cpu_time;
1257 ongoing_fast_rxt = wrk->ongoing_fast_rxt;
1258 vec_append (ongoing_fast_rxt, wrk->postponed_fast_rxt);
1259 vec_append (ongoing_fast_rxt, wrk->pending_fast_rxt);
1261 _vec_len (wrk->postponed_fast_rxt) = 0;
1262 _vec_len (wrk->pending_fast_rxt) = 0;
1264 max_burst_size = VLIB_FRAME_SIZE / vec_len (ongoing_fast_rxt);
1265 max_burst_size = clib_max (max_burst_size, 1);
1267 for (i = 0; i < vec_len (ongoing_fast_rxt); i++)
1269 if (n_segs >= VLIB_FRAME_SIZE)
1271 vec_add1 (wrk->postponed_fast_rxt, ongoing_fast_rxt[i]);
1275 tc = tcp_connection_get (ongoing_fast_rxt[i], thread_index);
1276 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1278 if (!tcp_in_fastrecovery (tc))
1281 burst_size = clib_min (max_burst_size, VLIB_FRAME_SIZE - n_segs);
1282 burst_bytes = transport_connection_tx_pacer_burst (&tc->connection,
1284 burst_size = clib_min (burst_size, burst_bytes / tc->snd_mss);
1287 tcp_program_fastretransmit (wrk, tc);
1291 n_segs_now = tcp_fast_retransmit (wrk, tc, burst_size);
1292 sent_bytes = clib_min (n_segs_now * tc->snd_mss, burst_bytes);
1293 transport_connection_tx_pacer_update_bytes (&tc->connection,
1295 n_segs += n_segs_now;
1297 _vec_len (ongoing_fast_rxt) = 0;
1298 wrk->ongoing_fast_rxt = ongoing_fast_rxt;
1302 * One function to rule them all ... and in the darkness bind them
1305 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1309 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1311 if (tc->bytes_acked)
1313 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1317 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1318 * it account for the bytes that left the network.
1320 else if (is_dack && !tcp_in_recovery (tc))
1322 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1323 ASSERT (tc->snd_una != tc->snd_una_max
1324 || tc->sack_sb.last_sacked_bytes);
1328 /* Pure duplicate ack. If some data got acked, it's handled lower */
1329 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1331 ASSERT (tcp_in_fastrecovery (tc));
1332 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1335 else if (tcp_should_fastrecover (tc))
1339 ASSERT (!tcp_in_fastrecovery (tc));
1341 /* Heuristic to catch potential late dupacks
1342 * after fast retransmit exits */
1343 if (is_dack && tc->snd_una == tc->snd_congestion
1344 && timestamp_leq (tc->rcv_opts.tsecr, tc->tsecr_last_ack))
1346 tc->rcv_dupacks = 0;
1350 tcp_cc_init_congestion (tc);
1351 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1353 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1355 tc->cwnd = tc->ssthresh;
1356 scoreboard_init_high_rxt (&tc->sack_sb, tc->snd_una);
1360 /* Post retransmit update cwnd to ssthresh and account for the
1361 * three segments that have left the network and should've been
1362 * buffered at the receiver XXX */
1363 tc->cwnd = tc->ssthresh + 3 * tc->snd_mss;
1366 /* Constrain rate until we get a partial ack */
1367 pacer_wnd = clib_max (0.1 * tc->cwnd, 2 * tc->snd_mss);
1368 tcp_connection_tx_pacer_reset (tc, pacer_wnd,
1369 0 /* start bucket */ );
1370 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index),
1374 else if (!tc->bytes_acked
1375 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1377 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1383 /* Don't allow entry in fast recovery if still in recovery, for now */
1384 else if (0 && is_dack && tcp_in_recovery (tc))
1386 /* If of of the two conditions lower hold, reset dupacks because
1387 * we're probably after timeout (RFC6582 heuristics).
1388 * If Cumulative ack does not cover more than congestion threshold,
1390 * 1) The following doesn't hold: The congestion window is greater
1391 * than SMSS bytes and the difference between highest_ack
1392 * and prev_highest_ack is at most 4*SMSS bytes
1393 * 2) Echoed timestamp in the last non-dup ack does not equal the
1396 if (seq_leq (tc->snd_una, tc->snd_congestion)
1397 && ((!(tc->cwnd > tc->snd_mss
1398 && tc->bytes_acked <= 4 * tc->snd_mss))
1399 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1401 tc->rcv_dupacks = 0;
1406 if (!tc->bytes_acked)
1410 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1413 * Legitimate ACK. 1) See if we can exit recovery
1416 /* Update the pacing rate. For the first partial ack we move from
1417 * the artificially constrained rate to the one after congestion */
1418 tcp_connection_tx_pacer_update (tc);
1420 if (seq_geq (tc->snd_una, tc->snd_congestion))
1422 tcp_retransmit_timer_update (tc);
1424 /* If spurious return, we've already updated everything */
1425 if (tcp_cc_recover (tc))
1427 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1431 tc->snd_nxt = tc->snd_una_max;
1433 /* Treat as congestion avoidance ack */
1434 tcp_cc_rcv_ack (tc);
1439 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1442 /* XXX limit this only to first partial ack? */
1443 tcp_retransmit_timer_update (tc);
1445 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1446 * reset dupacks to 0. Also needed if in congestion recovery */
1447 tc->rcv_dupacks = 0;
1449 /* Post RTO timeout don't try anything fancy */
1450 if (tcp_in_recovery (tc))
1452 tcp_cc_rcv_ack (tc);
1453 transport_add_tx_event (&tc->connection);
1457 /* Remove retransmitted bytes that have been delivered */
1458 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1460 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1461 >= tc->sack_sb.last_bytes_delivered
1462 || (tc->flags & TCP_CONN_FINSNT));
1464 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1465 * remove sacked bytes delivered */
1466 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1468 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1469 - tc->sack_sb.last_bytes_delivered;
1470 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1471 tc->snd_rxt_bytes -= rxt_delivered;
1475 /* Apparently all retransmitted holes have been acked */
1476 tc->snd_rxt_bytes = 0;
1477 tc->sack_sb.high_rxt = tc->snd_una;
1482 tcp_fastrecovery_first_on (tc);
1483 /* Reuse last bytes delivered to track total bytes acked */
1484 tc->sack_sb.last_bytes_delivered += tc->bytes_acked;
1485 if (tc->snd_rxt_bytes > tc->bytes_acked)
1486 tc->snd_rxt_bytes -= tc->bytes_acked;
1488 tc->snd_rxt_bytes = 0;
1491 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1494 * Since this was a partial ack, try to retransmit some more data
1496 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1500 * Process incoming ACK
1503 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1504 tcp_header_t * th, u32 * error)
1506 u32 prev_snd_wnd, prev_snd_una;
1509 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1511 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1512 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1514 /* When we entered recovery, we reset snd_nxt to snd_una. Seems peer
1515 * still has the data so accept the ack */
1516 if (tcp_in_recovery (tc)
1517 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_congestion))
1519 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1520 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
1521 tc->snd_una_max = tc->snd_nxt;
1525 /* If we have outstanding data and this is within the window, accept it,
1526 * probably retransmit has timed out. Otherwise ACK segment and then
1528 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1530 tcp_program_ack (wrk, tc);
1531 *error = TCP_ERROR_ACK_FUTURE;
1532 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1533 vnet_buffer (b)->tcp.ack_number);
1537 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1538 vnet_buffer (b)->tcp.ack_number);
1540 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1543 /* If old ACK, probably it's an old dupack */
1544 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1546 *error = TCP_ERROR_ACK_OLD;
1547 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1548 vnet_buffer (b)->tcp.ack_number);
1549 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1550 tcp_cc_handle_event (tc, 1);
1551 /* Don't drop yet */
1556 * Looks okay, process feedback
1559 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1560 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1562 prev_snd_wnd = tc->snd_wnd;
1563 prev_snd_una = tc->snd_una;
1564 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1565 vnet_buffer (b)->tcp.ack_number,
1566 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1567 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1568 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1569 tcp_validate_txf_size (tc, tc->bytes_acked);
1571 if (tc->bytes_acked)
1573 tcp_program_dequeue (wrk, tc);
1574 tcp_update_rtt (tc, vnet_buffer (b)->tcp.ack_number);
1577 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1580 * Check if we have congestion event
1583 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1585 tcp_cc_handle_event (tc, is_dack);
1586 if (!tcp_in_cong_recovery (tc))
1588 *error = TCP_ERROR_ACK_DUP;
1589 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1595 * Update congestion control (slow start/congestion avoidance)
1597 tcp_cc_update (tc, b);
1598 *error = TCP_ERROR_ACK_OK;
1603 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1605 if (!tcp_disconnect_pending (tc))
1607 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1608 tcp_disconnect_pending_on (tc);
1613 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1615 u32 thread_index, *pending_disconnects;
1616 tcp_connection_t *tc;
1619 if (!vec_len (wrk->pending_disconnects))
1622 thread_index = wrk->vm->thread_index;
1623 pending_disconnects = wrk->pending_disconnects;
1624 for (i = 0; i < vec_len (pending_disconnects); i++)
1626 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1627 tcp_disconnect_pending_off (tc);
1628 stream_session_disconnect_notify (&tc->connection);
1630 _vec_len (wrk->pending_disconnects) = 0;
1634 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1637 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1638 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1639 /* Account for the FIN if nothing else was received */
1640 if (vnet_buffer (b)->tcp.data_len == 0)
1642 tcp_program_ack (wrk, tc);
1643 tc->state = TCP_STATE_CLOSE_WAIT;
1644 tcp_program_disconnect (wrk, tc);
1645 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1646 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc);
1647 *error = TCP_ERROR_FIN_RCVD;
1651 tcp_sack_vector_is_sane (sack_block_t * sacks)
1654 for (i = 1; i < vec_len (sacks); i++)
1656 if (sacks[i - 1].end == sacks[i].start)
1663 * Build SACK list as per RFC2018.
1665 * Makes sure the first block contains the segment that generated the current
1666 * ACK and the following ones are the ones most recently reported in SACK
1669 * @param tc TCP connection for which the SACK list is updated
1670 * @param start Start sequence number of the newest SACK block
1671 * @param end End sequence of the newest SACK block
1674 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1676 sack_block_t *new_list = 0, *block = 0;
1679 /* If the first segment is ooo add it to the list. Last write might've moved
1680 * rcv_nxt over the first segment. */
1681 if (seq_lt (tc->rcv_nxt, start))
1683 vec_add2 (new_list, block, 1);
1684 block->start = start;
1688 /* Find the blocks still worth keeping. */
1689 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1691 /* Discard if rcv_nxt advanced beyond current block */
1692 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1695 /* Merge or drop if segment overlapped by the new segment */
1696 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1697 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1699 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1700 new_list[0].start = tc->snd_sacks[i].start;
1701 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1702 new_list[0].end = tc->snd_sacks[i].end;
1706 /* Save to new SACK list if we have space. */
1707 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1709 vec_add1 (new_list, tc->snd_sacks[i]);
1713 clib_warning ("sack discarded");
1717 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1719 /* Replace old vector with new one */
1720 vec_free (tc->snd_sacks);
1721 tc->snd_sacks = new_list;
1723 /* Segments should not 'touch' */
1724 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1728 tcp_sack_list_bytes (tcp_connection_t * tc)
1731 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1732 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1736 /** Enqueue data for delivery to application */
1738 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1741 int written, error = TCP_ERROR_ENQUEUED;
1743 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1745 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1746 1 /* queue event */ , 1);
1748 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1750 /* Update rcv_nxt */
1751 if (PREDICT_TRUE (written == data_len))
1753 tc->rcv_nxt += written;
1755 /* If more data written than expected, account for out-of-order bytes. */
1756 else if (written > data_len)
1758 tc->rcv_nxt += written;
1759 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1761 else if (written > 0)
1763 /* We've written something but FIFO is probably full now */
1764 tc->rcv_nxt += written;
1765 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1769 return TCP_ERROR_FIFO_FULL;
1772 /* Update SACK list if need be */
1773 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1775 /* Remove SACK blocks that have been delivered */
1776 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1782 /** Enqueue out-of-order data */
1784 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1787 stream_session_t *s0;
1790 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1793 /* Enqueue out-of-order data with relative offset */
1794 rv = session_enqueue_stream_connection (&tc->connection, b,
1795 vnet_buffer (b)->tcp.seq_number -
1796 tc->rcv_nxt, 0 /* queue event */ ,
1799 /* Nothing written */
1802 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1803 return TCP_ERROR_FIFO_FULL;
1806 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1808 /* Update SACK list if in use */
1809 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1811 ooo_segment_t *newest;
1814 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1816 /* Get the newest segment from the fifo */
1817 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1820 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1821 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1822 start = tc->rcv_nxt + offset;
1823 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1824 tcp_update_sack_list (tc, start, end);
1825 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1826 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1830 return TCP_ERROR_ENQUEUED_OOO;
1834 * Check if ACK could be delayed. If ack can be delayed, it should return
1835 * true for a full frame. If we're always acking return 0.
1838 tcp_can_delack (tcp_connection_t * tc)
1840 /* Send ack if ... */
1842 /* just sent a rcv wnd 0 */
1843 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1844 /* constrained to send ack */
1845 || (tc->flags & TCP_CONN_SNDACK) != 0
1846 /* we're almost out of tx wnd */
1847 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1854 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1856 u32 discard, first = b->current_length;
1857 vlib_main_t *vm = vlib_get_main ();
1859 /* Handle multi-buffer segments */
1860 if (n_bytes_to_drop > b->current_length)
1862 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1866 discard = clib_min (n_bytes_to_drop, b->current_length);
1867 vlib_buffer_advance (b, discard);
1868 b = vlib_get_buffer (vm, b->next_buffer);
1869 n_bytes_to_drop -= discard;
1871 while (n_bytes_to_drop);
1872 if (n_bytes_to_drop > first)
1873 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1876 vlib_buffer_advance (b, n_bytes_to_drop);
1877 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1882 * Receive buffer for connection and handle acks
1884 * It handles both in order or out-of-order data.
1887 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1890 u32 error, n_bytes_to_drop, n_data_bytes;
1892 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1893 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1894 ASSERT (n_data_bytes);
1896 /* Handle out-of-order data */
1897 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1899 /* Old sequence numbers allowed through because they overlapped
1901 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1903 /* Completely in the past (possible retransmit). Ack
1904 * retransmissions since we may not have any data to send */
1905 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1907 tcp_program_ack (wrk, tc);
1908 error = TCP_ERROR_SEGMENT_OLD;
1912 /* Chop off the bytes in the past and see if what is left
1913 * can be enqueued in order */
1914 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1915 n_data_bytes -= n_bytes_to_drop;
1916 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1917 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1919 error = TCP_ERROR_SEGMENT_OLD;
1925 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1926 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1927 tcp_program_dupack (wrk, tc);
1928 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1934 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1935 * segments can be enqueued after fifo tail offset changes. */
1936 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1937 if (tcp_can_delack (tc))
1939 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1940 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1944 tcp_program_ack (wrk, tc);
1952 tcp_header_t tcp_header;
1953 tcp_connection_t tcp_connection;
1957 format_tcp_rx_trace (u8 * s, va_list * args)
1959 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1960 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1961 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1962 u32 indent = format_get_indent (s);
1964 s = format (s, "%U\n%U%U",
1965 format_tcp_header, &t->tcp_header, 128,
1966 format_white_space, indent,
1967 format_tcp_connection, &t->tcp_connection, 1);
1973 format_tcp_rx_trace_short (u8 * s, va_list * args)
1975 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1976 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1977 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1979 s = format (s, "%d -> %d (%U)",
1980 clib_net_to_host_u16 (t->tcp_header.dst_port),
1981 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
1982 t->tcp_connection.state);
1988 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1989 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1993 clib_memcpy_fast (&t0->tcp_connection, tc0,
1994 sizeof (t0->tcp_connection));
1998 th0 = tcp_buffer_hdr (b0);
2000 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2004 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2005 vlib_frame_t * frame, u8 is_ip4)
2009 n_left = frame->n_vectors;
2010 from = vlib_frame_vector_args (frame);
2014 tcp_connection_t *tc0;
2021 b0 = vlib_get_buffer (vm, bi0);
2023 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2025 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2026 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2028 th0 = tcp_buffer_hdr (b0);
2029 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2038 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2039 u8 is_ip4, u32 evt, u32 val)
2042 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2044 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2047 #define tcp_maybe_inc_counter(node_id, err, count) \
2049 if (next0 != tcp_next_drop (is_ip4)) \
2050 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2051 tcp6_##node_id##_node.index, is_ip4, err, \
2054 #define tcp_inc_counter(node_id, err, count) \
2055 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2056 tcp6_##node_id##_node.index, is_ip4, \
2058 #define tcp_maybe_inc_err_counter(cnts, err) \
2060 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2062 #define tcp_inc_err_counter(cnts, err, val) \
2066 #define tcp_store_err_counters(node_id, cnts) \
2069 for (i = 0; i < TCP_N_ERROR; i++) \
2071 tcp_inc_counter(node_id, i, cnts[i]); \
2076 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2077 vlib_frame_t * frame, int is_ip4)
2079 u32 thread_index = vm->thread_index, errors = 0;
2080 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2081 u32 n_left_from, *from, *first_buffer;
2082 u16 err_counters[TCP_N_ERROR] = { 0 };
2085 if (node->flags & VLIB_NODE_FLAG_TRACE)
2086 tcp_established_trace_frame (vm, node, frame, is_ip4);
2088 first_buffer = from = vlib_frame_vector_args (frame);
2089 n_left_from = frame->n_vectors;
2091 while (n_left_from > 0)
2093 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2095 tcp_header_t *th0 = 0;
2096 tcp_connection_t *tc0;
2098 if (n_left_from > 1)
2101 pb = vlib_get_buffer (vm, from[1]);
2102 vlib_prefetch_buffer_header (pb, LOAD);
2103 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2110 b0 = vlib_get_buffer (vm, bi0);
2111 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2114 if (PREDICT_FALSE (tc0 == 0))
2116 error0 = TCP_ERROR_INVALID_CONNECTION;
2120 th0 = tcp_buffer_hdr (b0);
2121 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
2122 * dangling reference. */
2123 is_fin = tcp_is_fin (th0);
2125 /* SYNs, FINs and data consume sequence numbers */
2126 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2127 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
2129 /* TODO header prediction fast path */
2131 /* 1-4: check SEQ, RST, SYN */
2132 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2134 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2138 /* 5: check the ACK field */
2139 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2142 /* 6: check the URG bit TODO */
2144 /* 7: process the segment text */
2145 if (vnet_buffer (b0)->tcp.data_len)
2146 error0 = tcp_segment_rcv (wrk, tc0, b0);
2148 /* 8: check the FIN bit */
2149 if (PREDICT_FALSE (is_fin))
2150 tcp_rcv_fin (wrk, tc0, b0, &error0);
2153 tcp_inc_err_counter (err_counters, error0, 1);
2156 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2158 err_counters[TCP_ERROR_EVENT_FIFO_FULL] = errors;
2159 tcp_store_err_counters (established, err_counters);
2160 tcp_handle_postponed_dequeues (wrk);
2161 tcp_handle_disconnects (wrk);
2162 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2164 return frame->n_vectors;
2168 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2169 vlib_frame_t * from_frame)
2171 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2175 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2176 vlib_frame_t * from_frame)
2178 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2182 VLIB_REGISTER_NODE (tcp4_established_node) =
2184 .function = tcp4_established,
2185 .name = "tcp4-established",
2186 /* Takes a vector of packets. */
2187 .vector_size = sizeof (u32),
2188 .n_errors = TCP_N_ERROR,
2189 .error_strings = tcp_error_strings,
2190 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2193 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2194 foreach_tcp_state_next
2197 .format_trace = format_tcp_rx_trace_short,
2201 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
2204 VLIB_REGISTER_NODE (tcp6_established_node) =
2206 .function = tcp6_established,
2207 .name = "tcp6-established",
2208 /* Takes a vector of packets. */
2209 .vector_size = sizeof (u32),
2210 .n_errors = TCP_N_ERROR,
2211 .error_strings = tcp_error_strings,
2212 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2215 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2216 foreach_tcp_state_next
2219 .format_trace = format_tcp_rx_trace_short,
2224 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
2226 vlib_node_registration_t tcp4_syn_sent_node;
2227 vlib_node_registration_t tcp6_syn_sent_node;
2230 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2232 transport_connection_t *tmp = 0;
2239 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2242 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2243 && (tc->state == TCP_STATE_LISTEN
2244 || tc->c_rmt_port == hdr->src_port));
2248 handle = session_lookup_half_open_handle (&tc->connection);
2249 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2250 tc->c_proto, tc->c_is_ip4);
2254 if (tmp->lcl_port == hdr->dst_port
2255 && tmp->rmt_port == hdr->src_port)
2257 TCP_DBG ("half-open is valid!");
2265 * Lookup transport connection
2267 static tcp_connection_t *
2268 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2272 transport_connection_t *tconn;
2273 tcp_connection_t *tc;
2278 ip4 = vlib_buffer_get_current (b);
2279 tcp = ip4_next_header (ip4);
2280 tconn = session_lookup_connection_wt4 (fib_index,
2285 TRANSPORT_PROTO_TCP,
2286 thread_index, &is_filtered);
2287 tc = tcp_get_connection_from_transport (tconn);
2288 ASSERT (tcp_lookup_is_valid (tc, tcp));
2293 ip6 = vlib_buffer_get_current (b);
2294 tcp = ip6_next_header (ip6);
2295 tconn = session_lookup_connection_wt6 (fib_index,
2300 TRANSPORT_PROTO_TCP,
2301 thread_index, &is_filtered);
2302 tc = tcp_get_connection_from_transport (tconn);
2303 ASSERT (tcp_lookup_is_valid (tc, tcp));
2309 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2310 vlib_frame_t * from_frame, int is_ip4)
2312 tcp_main_t *tm = vnet_get_tcp_main ();
2313 u32 n_left_from, *from, *first_buffer, errors = 0;
2314 u32 my_thread_index = vm->thread_index;
2315 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2317 from = first_buffer = vlib_frame_vector_args (from_frame);
2318 n_left_from = from_frame->n_vectors;
2320 while (n_left_from > 0)
2322 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2323 tcp_connection_t *tc0, *new_tc0;
2324 tcp_header_t *tcp0 = 0;
2332 b0 = vlib_get_buffer (vm, bi0);
2334 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2335 if (PREDICT_FALSE (tc0 == 0))
2337 error0 = TCP_ERROR_INVALID_CONNECTION;
2341 /* Half-open completed recently but the connection was't removed
2342 * yet by the owning thread */
2343 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2345 /* Make sure the connection actually exists */
2346 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2347 my_thread_index, is_ip4));
2351 ack0 = vnet_buffer (b0)->tcp.ack_number;
2352 seq0 = vnet_buffer (b0)->tcp.seq_number;
2353 tcp0 = tcp_buffer_hdr (b0);
2355 /* Crude check to see if the connection handle does not match
2356 * the packet. Probably connection just switched to established */
2357 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2358 || tcp0->src_port != tc0->c_rmt_port))
2360 error0 = TCP_ERROR_INVALID_CONNECTION;
2364 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2365 && !tcp_syn (tcp0)))
2367 error0 = TCP_ERROR_SEGMENT_INVALID;
2371 /* SYNs, FINs and data consume sequence numbers */
2372 vnet_buffer (b0)->tcp.seq_end =
2373 seq0 + tcp_is_syn (tcp0) + tcp_is_fin (tcp0) +
2374 vnet_buffer (b0)->tcp.data_len;
2377 * 1. check the ACK bit
2381 * If the ACK bit is set
2382 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2383 * the RST bit is set, if so drop the segment and return)
2384 * <SEQ=SEG.ACK><CTL=RST>
2385 * and discard the segment. Return.
2386 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2390 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2392 if (!tcp_rst (tcp0))
2393 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2394 error0 = TCP_ERROR_RCV_WND;
2398 /* Make sure ACK is valid */
2399 if (seq_gt (tc0->snd_una, ack0))
2401 error0 = TCP_ERROR_ACK_INVALID;
2407 * 2. check the RST bit
2412 /* If ACK is acceptable, signal client that peer is not
2413 * willing to accept connection and drop connection*/
2415 tcp_connection_reset (tc0);
2416 error0 = TCP_ERROR_RST_RCVD;
2421 * 3. check the security and precedence (skipped)
2425 * 4. check the SYN bit
2428 /* No SYN flag. Drop. */
2429 if (!tcp_syn (tcp0))
2431 clib_warning ("not synack");
2432 error0 = TCP_ERROR_SEGMENT_INVALID;
2437 if (tcp_options_parse (tcp0, &tc0->rcv_opts))
2439 clib_warning ("options parse fail");
2440 error0 = TCP_ERROR_OPTIONS;
2444 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2445 * current thread pool. */
2446 pool_get (tm->connections[my_thread_index], new_tc0);
2447 clib_memcpy_fast (new_tc0, tc0, sizeof (*new_tc0));
2448 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2449 new_tc0->c_thread_index = my_thread_index;
2450 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2451 new_tc0->irs = seq0;
2452 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
2453 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2454 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2456 /* If this is not the owning thread, wait for syn retransmit to
2457 * expire and cleanup then */
2458 if (tcp_half_open_connection_cleanup (tc0))
2459 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2461 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2463 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2464 new_tc0->tsval_recent_age = tcp_time_now ();
2467 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2468 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2470 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2471 << new_tc0->snd_wscale;
2472 new_tc0->snd_wl1 = seq0;
2473 new_tc0->snd_wl2 = ack0;
2475 tcp_connection_init_vars (new_tc0);
2477 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2478 if (PREDICT_TRUE (tcp_ack (tcp0)))
2480 /* Our SYN is ACKed: we have iss < ack = snd_una */
2482 /* TODO Dequeue acknowledged segments if we support Fast Open */
2483 new_tc0->snd_una = ack0;
2484 new_tc0->state = TCP_STATE_ESTABLISHED;
2486 /* Make sure las is initialized for the wnd computation */
2487 new_tc0->rcv_las = new_tc0->rcv_nxt;
2489 /* Notify app that we have connection. If session layer can't
2490 * allocate session send reset */
2491 if (session_stream_connect_notify (&new_tc0->connection, 0))
2493 clib_warning ("connect notify fail");
2494 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2495 tcp_connection_cleanup (new_tc0);
2499 new_tc0->tx_fifo_size =
2500 transport_tx_fifo_size (&new_tc0->connection);
2501 /* Update rtt with the syn-ack sample */
2502 tcp_estimate_initial_rtt (new_tc0);
2503 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2504 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2506 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2509 new_tc0->state = TCP_STATE_SYN_RCVD;
2511 /* Notify app that we have connection */
2512 if (session_stream_connect_notify (&new_tc0->connection, 0))
2514 tcp_connection_cleanup (new_tc0);
2515 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2516 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2520 new_tc0->tx_fifo_size =
2521 transport_tx_fifo_size (&new_tc0->connection);
2522 new_tc0->rtt_ts = 0;
2523 tcp_init_snd_vars (new_tc0);
2524 tcp_send_synack (new_tc0);
2525 error0 = TCP_ERROR_SYNS_RCVD;
2529 /* Read data, if any */
2530 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2532 clib_warning ("rcvd data in syn-sent");
2533 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2534 if (error0 == TCP_ERROR_ACK_OK)
2535 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2539 tcp_program_ack (wrk, new_tc0);
2544 tcp_inc_counter (syn_sent, error0, 1);
2545 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2547 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2548 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2549 clib_memcpy_fast (&t0->tcp_connection, tc0,
2550 sizeof (t0->tcp_connection));
2554 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2556 tcp_inc_counter (syn_sent, TCP_ERROR_EVENT_FIFO_FULL, errors);
2557 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2559 return from_frame->n_vectors;
2563 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2564 vlib_frame_t * from_frame)
2566 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2570 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2571 vlib_frame_t * from_frame)
2573 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2577 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2579 .function = tcp4_syn_sent,
2580 .name = "tcp4-syn-sent",
2581 /* Takes a vector of packets. */
2582 .vector_size = sizeof (u32),
2583 .n_errors = TCP_N_ERROR,
2584 .error_strings = tcp_error_strings,
2585 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2588 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2589 foreach_tcp_state_next
2592 .format_trace = format_tcp_rx_trace_short,
2596 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2599 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2601 .function = tcp6_syn_sent_rcv,
2602 .name = "tcp6-syn-sent",
2603 /* Takes a vector of packets. */
2604 .vector_size = sizeof (u32),
2605 .n_errors = TCP_N_ERROR,
2606 .error_strings = tcp_error_strings,
2607 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2610 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2611 foreach_tcp_state_next
2614 .format_trace = format_tcp_rx_trace_short,
2618 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2620 vlib_node_registration_t tcp4_rcv_process_node;
2621 vlib_node_registration_t tcp6_rcv_process_node;
2624 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2625 * as per RFC793 p. 64
2628 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2629 vlib_frame_t * from_frame, int is_ip4)
2631 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2632 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2633 u32 n_left_from, *from;
2635 from = first_buffer = vlib_frame_vector_args (from_frame);
2636 n_left_from = from_frame->n_vectors;
2638 while (n_left_from > 0)
2640 u32 bi0, error0 = TCP_ERROR_NONE;
2641 tcp_header_t *tcp0 = 0;
2642 tcp_connection_t *tc0;
2650 b0 = vlib_get_buffer (vm, bi0);
2651 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2653 if (PREDICT_FALSE (tc0 == 0))
2655 error0 = TCP_ERROR_INVALID_CONNECTION;
2659 tcp0 = tcp_buffer_hdr (b0);
2660 is_fin0 = tcp_is_fin (tcp0);
2662 /* SYNs, FINs and data consume sequence numbers */
2663 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2664 + tcp_is_syn (tcp0) + is_fin0 + vnet_buffer (b0)->tcp.data_len;
2668 tcp_connection_t *tmp;
2669 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2671 if (tmp->state != tc0->state)
2673 clib_warning ("state changed");
2679 * Special treatment for CLOSED
2681 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2683 error0 = TCP_ERROR_CONNECTION_CLOSED;
2688 * For all other states (except LISTEN)
2691 /* 1-4: check SEQ, RST, SYN */
2692 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2695 /* 5: check the ACK field */
2698 case TCP_STATE_SYN_RCVD:
2700 * If the segment acknowledgment is not acceptable, form a
2702 * <SEQ=SEG.ACK><CTL=RST>
2705 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2707 TCP_DBG ("connection not accepted");
2708 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2709 error0 = TCP_ERROR_ACK_INVALID;
2713 /* Update rtt and rto */
2714 tcp_estimate_initial_rtt (tc0);
2716 /* Switch state to ESTABLISHED */
2717 tc0->state = TCP_STATE_ESTABLISHED;
2718 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2720 /* Initialize session variables */
2721 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2722 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2723 << tc0->rcv_opts.wscale;
2724 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2725 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2727 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2728 tcp_retransmit_timer_reset (tc0);
2729 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2730 stream_session_accept_notify (&tc0->connection);
2731 error0 = TCP_ERROR_ACK_OK;
2733 case TCP_STATE_ESTABLISHED:
2734 /* We can get packets in established state here because they
2735 * were enqueued before state change */
2736 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2740 case TCP_STATE_FIN_WAIT_1:
2741 /* In addition to the processing for the ESTABLISHED state, if
2742 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2743 * continue processing in that state. */
2744 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2747 /* Still have to send the FIN */
2748 if (tc0->flags & TCP_CONN_FINPNDG)
2750 /* TX fifo finally drained */
2751 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2754 /* If FIN is ACKed */
2755 else if (tc0->snd_una == tc0->snd_una_max)
2757 tc0->state = TCP_STATE_FIN_WAIT_2;
2758 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2760 /* Stop all retransmit timers because we have nothing more
2761 * to send. Enable waitclose though because we're willing to
2762 * wait for peer's FIN but not indefinitely. */
2763 tcp_connection_timers_reset (tc0);
2764 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2766 /* Don't try to deq the FIN acked */
2767 if (tc0->burst_acked > 1)
2768 stream_session_dequeue_drop (&tc0->connection,
2769 tc0->burst_acked - 1);
2770 tc0->burst_acked = 0;
2773 case TCP_STATE_FIN_WAIT_2:
2774 /* In addition to the processing for the ESTABLISHED state, if
2775 * the retransmission queue is empty, the user's CLOSE can be
2776 * acknowledged ("ok") but do not delete the TCB. */
2777 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2779 tc0->burst_acked = 0;
2781 case TCP_STATE_CLOSE_WAIT:
2782 /* Do the same processing as for the ESTABLISHED state. */
2783 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2786 if (tc0->flags & TCP_CONN_FINPNDG)
2788 /* TX fifo finally drained */
2789 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2792 tcp_connection_timers_reset (tc0);
2793 tc0->state = TCP_STATE_LAST_ACK;
2794 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2798 case TCP_STATE_CLOSING:
2799 /* In addition to the processing for the ESTABLISHED state, if
2800 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2801 * otherwise ignore the segment. */
2802 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2805 tc0->state = TCP_STATE_TIME_WAIT;
2806 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2807 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2811 case TCP_STATE_LAST_ACK:
2812 /* The only thing that [should] arrive in this state is an
2813 * acknowledgment of our FIN. If our FIN is now acknowledged,
2814 * delete the TCB, enter the CLOSED state, and return. */
2816 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2818 error0 = TCP_ERROR_ACK_INVALID;
2821 error0 = TCP_ERROR_ACK_OK;
2822 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2823 /* Apparently our ACK for the peer's FIN was lost */
2824 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2830 tc0->state = TCP_STATE_CLOSED;
2831 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2833 /* Don't free the connection from the data path since
2834 * we can't ensure that we have no packets already enqueued
2835 * to output. Rely instead on the waitclose timer */
2836 tcp_connection_timers_reset (tc0);
2837 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, 1);
2842 case TCP_STATE_TIME_WAIT:
2843 /* The only thing that can arrive in this state is a
2844 * retransmission of the remote FIN. Acknowledge it, and restart
2845 * the 2 MSL timeout. */
2847 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2850 tcp_program_ack (wrk, tc0);
2851 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2859 /* 6: check the URG bit TODO */
2861 /* 7: process the segment text */
2864 case TCP_STATE_ESTABLISHED:
2865 case TCP_STATE_FIN_WAIT_1:
2866 case TCP_STATE_FIN_WAIT_2:
2867 if (vnet_buffer (b0)->tcp.data_len)
2868 error0 = tcp_segment_rcv (wrk, tc0, b0);
2872 case TCP_STATE_CLOSE_WAIT:
2873 case TCP_STATE_CLOSING:
2874 case TCP_STATE_LAST_ACK:
2875 case TCP_STATE_TIME_WAIT:
2876 /* This should not occur, since a FIN has been received from the
2877 * remote side. Ignore the segment text. */
2881 /* 8: check the FIN bit */
2887 case TCP_STATE_ESTABLISHED:
2888 case TCP_STATE_SYN_RCVD:
2889 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2890 tcp_connection_timers_reset (tc0);
2892 stream_session_disconnect_notify (&tc0->connection);
2893 tc0->state = TCP_STATE_CLOSE_WAIT;
2894 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2896 case TCP_STATE_CLOSE_WAIT:
2897 case TCP_STATE_CLOSING:
2898 case TCP_STATE_LAST_ACK:
2901 case TCP_STATE_FIN_WAIT_1:
2902 tc0->state = TCP_STATE_CLOSING;
2903 tcp_program_ack (wrk, tc0);
2904 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2905 /* Wait for ACK but not forever */
2906 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2908 case TCP_STATE_FIN_WAIT_2:
2909 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2910 tc0->state = TCP_STATE_TIME_WAIT;
2911 tcp_connection_timers_reset (tc0);
2912 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2913 tcp_program_ack (wrk, tc0);
2914 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2916 case TCP_STATE_TIME_WAIT:
2917 /* Remain in the TIME-WAIT state. Restart the time-wait
2920 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2923 error0 = TCP_ERROR_FIN_RCVD;
2924 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2928 tcp_inc_counter (rcv_process, error0, 1);
2929 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2931 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2932 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2936 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2938 tcp_inc_counter (rcv_process, TCP_ERROR_EVENT_FIFO_FULL, errors);
2939 tcp_handle_postponed_dequeues (wrk);
2940 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2942 return from_frame->n_vectors;
2946 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2947 vlib_frame_t * from_frame)
2949 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2953 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2954 vlib_frame_t * from_frame)
2956 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2960 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2962 .function = tcp4_rcv_process,
2963 .name = "tcp4-rcv-process",
2964 /* Takes a vector of packets. */
2965 .vector_size = sizeof (u32),
2966 .n_errors = TCP_N_ERROR,
2967 .error_strings = tcp_error_strings,
2968 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2971 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2972 foreach_tcp_state_next
2975 .format_trace = format_tcp_rx_trace_short,
2979 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2982 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2984 .function = tcp6_rcv_process,
2985 .name = "tcp6-rcv-process",
2986 /* Takes a vector of packets. */
2987 .vector_size = sizeof (u32),
2988 .n_errors = TCP_N_ERROR,
2989 .error_strings = tcp_error_strings,
2990 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2993 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2994 foreach_tcp_state_next
2997 .format_trace = format_tcp_rx_trace_short,
3001 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
3003 vlib_node_registration_t tcp4_listen_node;
3004 vlib_node_registration_t tcp6_listen_node;
3007 * LISTEN state processing as per RFC 793 p. 65
3010 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3011 vlib_frame_t * from_frame, int is_ip4)
3013 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3014 u32 my_thread_index = vm->thread_index;
3016 from = first_buffer = vlib_frame_vector_args (from_frame);
3017 n_left_from = from_frame->n_vectors;
3019 while (n_left_from > 0)
3024 tcp_header_t *th0 = 0;
3025 tcp_connection_t *lc0;
3028 tcp_connection_t *child0;
3029 u32 error0 = TCP_ERROR_NONE;
3035 b0 = vlib_get_buffer (vm, bi0);
3036 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3040 ip40 = vlib_buffer_get_current (b0);
3041 th0 = ip4_next_header (ip40);
3045 ip60 = vlib_buffer_get_current (b0);
3046 th0 = ip6_next_header (ip60);
3049 /* Create child session. For syn-flood protection use filter */
3051 /* 1. first check for an RST: handled in dispatch */
3052 /* if (tcp_rst (th0))
3056 /* 2. second check for an ACK: handled in dispatch */
3057 /* if (tcp_ack (th0))
3059 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, my_thread_index,
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_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3091 sizeof (ip6_address_t));
3092 clib_memcpy_fast (&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 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3136 tcp_send_synack (child0);
3137 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_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3145 clib_memcpy_fast (&t0->tcp_connection, lc0,
3146 sizeof (t0->tcp_connection));
3149 n_syns += (error0 == TCP_ERROR_NONE);
3152 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3153 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3155 return from_frame->n_vectors;
3159 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3160 vlib_frame_t * from_frame)
3162 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3166 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3167 vlib_frame_t * from_frame)
3169 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3173 VLIB_REGISTER_NODE (tcp4_listen_node) =
3175 .function = tcp4_listen,
3176 .name = "tcp4-listen",
3177 /* Takes a vector of packets. */
3178 .vector_size = sizeof (u32),
3179 .n_errors = TCP_N_ERROR,
3180 .error_strings = tcp_error_strings,
3181 .n_next_nodes = TCP_LISTEN_N_NEXT,
3184 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3185 foreach_tcp_state_next
3188 .format_trace = format_tcp_rx_trace_short,
3192 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
3195 VLIB_REGISTER_NODE (tcp6_listen_node) =
3197 .function = tcp6_listen,
3198 .name = "tcp6-listen",
3199 /* Takes a vector of packets. */
3200 .vector_size = sizeof (u32),
3201 .n_errors = TCP_N_ERROR,
3202 .error_strings = tcp_error_strings,
3203 .n_next_nodes = TCP_LISTEN_N_NEXT,
3206 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3207 foreach_tcp_state_next
3210 .format_trace = format_tcp_rx_trace_short,
3214 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
3216 vlib_node_registration_t tcp4_input_node;
3217 vlib_node_registration_t tcp6_input_node;
3219 typedef enum _tcp_input_next
3221 TCP_INPUT_NEXT_DROP,
3222 TCP_INPUT_NEXT_LISTEN,
3223 TCP_INPUT_NEXT_RCV_PROCESS,
3224 TCP_INPUT_NEXT_SYN_SENT,
3225 TCP_INPUT_NEXT_ESTABLISHED,
3226 TCP_INPUT_NEXT_RESET,
3227 TCP_INPUT_NEXT_PUNT,
3231 #define foreach_tcp4_input_next \
3232 _ (DROP, "ip4-drop") \
3233 _ (LISTEN, "tcp4-listen") \
3234 _ (RCV_PROCESS, "tcp4-rcv-process") \
3235 _ (SYN_SENT, "tcp4-syn-sent") \
3236 _ (ESTABLISHED, "tcp4-established") \
3237 _ (RESET, "tcp4-reset") \
3238 _ (PUNT, "ip4-punt")
3240 #define foreach_tcp6_input_next \
3241 _ (DROP, "ip6-drop") \
3242 _ (LISTEN, "tcp6-listen") \
3243 _ (RCV_PROCESS, "tcp6-rcv-process") \
3244 _ (SYN_SENT, "tcp6-syn-sent") \
3245 _ (ESTABLISHED, "tcp6-established") \
3246 _ (RESET, "tcp6-reset") \
3247 _ (PUNT, "ip6-punt")
3249 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3252 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3253 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3255 tcp_connection_t *tc;
3260 for (i = 0; i < n_bufs; i++)
3262 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3264 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3265 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3267 tcp = vlib_buffer_get_current (bs[i]);
3268 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3274 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3276 if (*error == TCP_ERROR_FILTERED)
3278 *next = TCP_INPUT_NEXT_DROP;
3280 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3282 *next = TCP_INPUT_NEXT_PUNT;
3283 *error = TCP_ERROR_PUNT;
3287 *next = TCP_INPUT_NEXT_RESET;
3288 *error = TCP_ERROR_NO_LISTENER;
3292 static inline tcp_connection_t *
3293 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3296 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3297 int n_advance_bytes, n_data_bytes;
3298 transport_connection_t *tc;
3304 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3305 tcp = ip4_next_header (ip4);
3306 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3307 n_advance_bytes = (ip4_header_bytes (ip4) + tcp_header_bytes (tcp));
3308 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3310 /* Length check. Checksum computed by ipx_local no need to compute again */
3311 if (PREDICT_FALSE (n_advance_bytes < 0))
3313 *error = TCP_ERROR_LENGTH;
3317 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3318 &ip4->src_address, tcp->dst_port,
3319 tcp->src_port, TRANSPORT_PROTO_TCP,
3320 thread_index, &is_filtered);
3324 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3325 tcp = ip6_next_header (ip6);
3326 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3327 n_advance_bytes = tcp_header_bytes (tcp);
3328 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3330 n_advance_bytes += sizeof (ip6[0]);
3332 if (PREDICT_FALSE (n_advance_bytes < 0))
3334 *error = TCP_ERROR_LENGTH;
3338 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3339 &ip6->src_address, tcp->dst_port,
3340 tcp->src_port, TRANSPORT_PROTO_TCP,
3341 thread_index, &is_filtered);
3344 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3345 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3346 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3347 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3348 vnet_buffer (b)->tcp.flags = 0;
3350 *error = is_filtered ? TCP_ERROR_FILTERED : *error;
3352 return tcp_get_connection_from_transport (tc);
3356 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3357 vlib_buffer_t * b, u16 * next, u32 * error)
3362 tcp = tcp_buffer_hdr (b);
3363 flags = tcp->flags & filter_flags;
3364 *next = tm->dispatch_table[tc->state][flags].next;
3365 *error = tm->dispatch_table[tc->state][flags].error;
3367 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3368 || *next == TCP_INPUT_NEXT_RESET))
3370 /* Overload tcp flags to store state */
3371 tcp_state_t state = tc->state;
3372 vnet_buffer (b)->tcp.flags = tc->state;
3374 if (*error == TCP_ERROR_DISPATCH)
3375 clib_warning ("disp error state %U flags %U", format_tcp_state,
3376 state, format_tcp_flags, (int) flags);
3381 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3382 vlib_frame_t * frame, int is_ip4)
3384 u32 n_left_from, *from, thread_index = vm->thread_index;
3385 tcp_main_t *tm = vnet_get_tcp_main ();
3386 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3387 u16 nexts[VLIB_FRAME_SIZE], *next;
3389 tcp_set_time_now (tcp_get_worker (thread_index));
3391 from = vlib_frame_vector_args (frame);
3392 n_left_from = frame->n_vectors;
3393 vlib_get_buffers (vm, from, bufs, n_left_from);
3398 while (n_left_from >= 4)
3400 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3401 tcp_connection_t *tc0, *tc1;
3404 vlib_prefetch_buffer_header (b[2], STORE);
3405 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3407 vlib_prefetch_buffer_header (b[3], STORE);
3408 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3411 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3413 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3414 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4);
3416 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3418 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3419 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3421 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3422 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3424 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3425 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3429 if (PREDICT_TRUE (tc0 != 0))
3431 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3432 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3433 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3436 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3438 if (PREDICT_TRUE (tc1 != 0))
3440 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3441 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3442 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3445 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3452 while (n_left_from > 0)
3454 tcp_connection_t *tc0;
3455 u32 error0 = TCP_ERROR_NO_LISTENER;
3457 if (n_left_from > 1)
3459 vlib_prefetch_buffer_header (b[1], STORE);
3460 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3463 next[0] = TCP_INPUT_NEXT_DROP;
3464 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3465 if (PREDICT_TRUE (tc0 != 0))
3467 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3468 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3469 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3472 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3479 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3480 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3482 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3483 return frame->n_vectors;
3487 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3488 vlib_frame_t * from_frame)
3490 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3494 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3495 vlib_frame_t * from_frame)
3497 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3501 VLIB_REGISTER_NODE (tcp4_input_node) =
3503 .function = tcp4_input,
3504 .name = "tcp4-input",
3505 /* Takes a vector of packets. */
3506 .vector_size = sizeof (u32),
3507 .n_errors = TCP_N_ERROR,
3508 .error_strings = tcp_error_strings,
3509 .n_next_nodes = TCP_INPUT_N_NEXT,
3512 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3513 foreach_tcp4_input_next
3516 .format_buffer = format_tcp_header,
3517 .format_trace = format_tcp_rx_trace,
3521 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3524 VLIB_REGISTER_NODE (tcp6_input_node) =
3526 .function = tcp6_input,
3527 .name = "tcp6-input",
3528 /* Takes a vector of packets. */
3529 .vector_size = sizeof (u32),
3530 .n_errors = TCP_N_ERROR,
3531 .error_strings = tcp_error_strings,
3532 .n_next_nodes = TCP_INPUT_N_NEXT,
3535 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3536 foreach_tcp6_input_next
3539 .format_buffer = format_tcp_header,
3540 .format_trace = format_tcp_rx_trace,
3544 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3547 tcp_dispatch_table_init (tcp_main_t * tm)
3550 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3551 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3553 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3554 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3557 #define _(t,f,n,e) \
3559 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3560 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3563 /* SYNs for new connections -> tcp-listen. */
3564 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3565 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3566 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_RST_RCVD);
3567 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3569 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3570 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3571 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3572 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3574 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3575 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3577 /* SYN-ACK for a SYN */
3578 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3580 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3581 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3582 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3584 /* ACK for for established connection -> tcp-established. */
3585 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3586 /* FIN for for established connection -> tcp-established. */
3587 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3588 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3590 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3591 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3593 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3594 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3596 /* ACK or FIN-ACK to our FIN */
3597 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3598 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3600 /* FIN in reply to our FIN from the other side */
3601 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3602 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3603 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3604 /* FIN confirming that the peer (app) has closed */
3605 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3606 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3607 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3609 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3610 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3612 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3613 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3614 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3616 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3617 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3618 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3619 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3621 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3622 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3623 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3624 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3625 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3626 TCP_ERROR_CONNECTION_CLOSED);
3630 static clib_error_t *
3631 tcp_input_init (vlib_main_t * vm)
3633 clib_error_t *error = 0;
3634 tcp_main_t *tm = vnet_get_tcp_main ();
3636 if ((error = vlib_call_init_function (vm, tcp_init)))
3639 /* Initialize dispatch table. */
3640 tcp_dispatch_table_init (tm);
3645 VLIB_INIT_FUNCTION (tcp_input_init);
3648 * fd.io coding-style-patch-verification: ON
3651 * eval: (c-set-style "gnu")