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_1_smss_off (tc);
1135 tcp_fastrecovery_first_off (tc);
1137 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1141 tcp_cc_congestion_undo (tcp_connection_t * tc)
1143 tc->cwnd = tc->prev_cwnd;
1144 tc->ssthresh = tc->prev_ssthresh;
1145 tc->snd_nxt = tc->snd_una_max;
1146 tc->rcv_dupacks = 0;
1147 if (tcp_in_recovery (tc))
1148 tcp_cc_recovery_exit (tc);
1149 else if (tcp_in_fastrecovery (tc))
1150 tcp_cc_fastrecovery_exit (tc);
1151 ASSERT (tc->rto_boff == 0);
1152 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
1156 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1158 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1160 && tcp_opts_tstamp (&tc->rcv_opts)
1161 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1165 tcp_cc_is_spurious_fast_rxt (tcp_connection_t * tc)
1167 return (tcp_in_fastrecovery (tc)
1168 && tc->cwnd > tc->ssthresh + 3 * tc->snd_mss);
1172 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1174 return (tcp_cc_is_spurious_timeout_rxt (tc)
1175 || tcp_cc_is_spurious_fast_rxt (tc));
1179 tcp_cc_recover (tcp_connection_t * tc)
1181 ASSERT (tcp_in_cong_recovery (tc));
1182 if (tcp_cc_is_spurious_retransmit (tc))
1184 tcp_cc_congestion_undo (tc);
1188 if (tcp_in_recovery (tc))
1189 tcp_cc_recovery_exit (tc);
1190 else if (tcp_in_fastrecovery (tc))
1191 tcp_cc_fastrecovery_exit (tc);
1193 ASSERT (tc->rto_boff == 0);
1194 ASSERT (!tcp_in_cong_recovery (tc));
1195 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1200 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
1202 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1204 /* Congestion avoidance */
1205 tcp_cc_rcv_ack (tc);
1207 /* If a cumulative ack, make sure dupacks is 0 */
1208 tc->rcv_dupacks = 0;
1210 /* When dupacks hits the threshold we only enter fast retransmit if
1211 * cumulative ack covers more than snd_congestion. Should snd_una
1212 * wrap this test may fail under otherwise valid circumstances.
1213 * Therefore, proactively update snd_congestion when wrap detected. */
1215 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1216 && seq_gt (tc->snd_congestion, tc->snd_una)))
1217 tc->snd_congestion = tc->snd_una - 1;
1221 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1223 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1227 tcp_should_fastrecover (tcp_connection_t * tc)
1229 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1230 || tcp_should_fastrecover_sack (tc));
1234 tcp_program_fastretransmit (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1236 if (!(tc->flags & TCP_CONN_FRXT_PENDING))
1238 vec_add1 (wrk->pending_fast_rxt, tc->c_c_index);
1239 tc->flags |= TCP_CONN_FRXT_PENDING;
1244 tcp_do_fastretransmits (tcp_worker_ctx_t * wrk)
1246 u32 *ongoing_fast_rxt, burst_bytes, sent_bytes, thread_index;
1247 u32 max_burst_size, burst_size, n_segs = 0, n_segs_now;
1248 tcp_connection_t *tc;
1252 if (vec_len (wrk->pending_fast_rxt) == 0
1253 && vec_len (wrk->postponed_fast_rxt) == 0)
1256 thread_index = wrk->vm->thread_index;
1257 last_cpu_time = wrk->vm->clib_time.last_cpu_time;
1258 ongoing_fast_rxt = wrk->ongoing_fast_rxt;
1259 vec_append (ongoing_fast_rxt, wrk->postponed_fast_rxt);
1260 vec_append (ongoing_fast_rxt, wrk->pending_fast_rxt);
1262 _vec_len (wrk->postponed_fast_rxt) = 0;
1263 _vec_len (wrk->pending_fast_rxt) = 0;
1265 max_burst_size = VLIB_FRAME_SIZE / vec_len (ongoing_fast_rxt);
1266 max_burst_size = clib_max (max_burst_size, 1);
1268 for (i = 0; i < vec_len (ongoing_fast_rxt); i++)
1270 if (n_segs >= VLIB_FRAME_SIZE)
1272 vec_add1 (wrk->postponed_fast_rxt, ongoing_fast_rxt[i]);
1276 tc = tcp_connection_get (ongoing_fast_rxt[i], thread_index);
1277 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1279 if (!tcp_in_fastrecovery (tc))
1282 burst_size = clib_min (max_burst_size, VLIB_FRAME_SIZE - n_segs);
1283 burst_bytes = transport_connection_tx_pacer_burst (&tc->connection,
1285 burst_size = clib_min (burst_size, burst_bytes / tc->snd_mss);
1288 tcp_program_fastretransmit (wrk, tc);
1292 n_segs_now = tcp_fast_retransmit (wrk, tc, burst_size);
1293 sent_bytes = clib_min (n_segs_now * tc->snd_mss, burst_bytes);
1294 transport_connection_tx_pacer_update_bytes (&tc->connection,
1296 n_segs += n_segs_now;
1298 _vec_len (ongoing_fast_rxt) = 0;
1299 wrk->ongoing_fast_rxt = ongoing_fast_rxt;
1303 * One function to rule them all ... and in the darkness bind them
1306 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1310 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1312 if (tc->bytes_acked)
1314 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1318 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1319 * it account for the bytes that left the network.
1321 else if (is_dack && !tcp_in_recovery (tc))
1323 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1324 ASSERT (tc->snd_una != tc->snd_una_max
1325 || tc->sack_sb.last_sacked_bytes);
1329 /* Pure duplicate ack. If some data got acked, it's handled lower */
1330 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1332 ASSERT (tcp_in_fastrecovery (tc));
1333 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1336 else if (tcp_should_fastrecover (tc))
1340 ASSERT (!tcp_in_fastrecovery (tc));
1342 /* Heuristic to catch potential late dupacks
1343 * after fast retransmit exits */
1344 if (is_dack && tc->snd_una == tc->snd_congestion
1345 && timestamp_leq (tc->rcv_opts.tsecr, tc->tsecr_last_ack))
1347 tc->rcv_dupacks = 0;
1351 tcp_cc_init_congestion (tc);
1352 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1354 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1356 tc->cwnd = tc->ssthresh;
1357 scoreboard_init_high_rxt (&tc->sack_sb, tc->snd_una);
1361 /* Post retransmit update cwnd to ssthresh and account for the
1362 * three segments that have left the network and should've been
1363 * buffered at the receiver XXX */
1364 tc->cwnd = tc->ssthresh + 3 * tc->snd_mss;
1367 /* Constrain rate until we get a partial ack */
1368 pacer_wnd = clib_max (0.1 * tc->cwnd, 2 * tc->snd_mss);
1369 tcp_connection_tx_pacer_reset (tc, pacer_wnd,
1370 0 /* start bucket */ );
1371 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index),
1375 else if (!tc->bytes_acked
1376 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1378 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1384 /* Don't allow entry in fast recovery if still in recovery, for now */
1385 else if (0 && is_dack && tcp_in_recovery (tc))
1387 /* If of of the two conditions lower hold, reset dupacks because
1388 * we're probably after timeout (RFC6582 heuristics).
1389 * If Cumulative ack does not cover more than congestion threshold,
1391 * 1) The following doesn't hold: The congestion window is greater
1392 * than SMSS bytes and the difference between highest_ack
1393 * and prev_highest_ack is at most 4*SMSS bytes
1394 * 2) Echoed timestamp in the last non-dup ack does not equal the
1397 if (seq_leq (tc->snd_una, tc->snd_congestion)
1398 && ((!(tc->cwnd > tc->snd_mss
1399 && tc->bytes_acked <= 4 * tc->snd_mss))
1400 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1402 tc->rcv_dupacks = 0;
1407 if (!tc->bytes_acked)
1411 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1414 * Legitimate ACK. 1) See if we can exit recovery
1417 /* Update the pacing rate. For the first partial ack we move from
1418 * the artificially constrained rate to the one after congestion */
1419 tcp_connection_tx_pacer_update (tc);
1421 if (seq_geq (tc->snd_una, tc->snd_congestion))
1423 tcp_retransmit_timer_update (tc);
1425 /* If spurious return, we've already updated everything */
1426 if (tcp_cc_recover (tc))
1428 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1432 tc->snd_nxt = tc->snd_una_max;
1434 /* Treat as congestion avoidance ack */
1435 tcp_cc_rcv_ack (tc);
1440 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1443 /* XXX limit this only to first partial ack? */
1444 tcp_retransmit_timer_update (tc);
1446 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1447 * reset dupacks to 0. Also needed if in congestion recovery */
1448 tc->rcv_dupacks = 0;
1450 /* Post RTO timeout don't try anything fancy */
1451 if (tcp_in_recovery (tc))
1453 tcp_cc_rcv_ack (tc);
1454 transport_add_tx_event (&tc->connection);
1458 /* Remove retransmitted bytes that have been delivered */
1459 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1461 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1462 >= tc->sack_sb.last_bytes_delivered
1463 || (tc->flags & TCP_CONN_FINSNT));
1465 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1466 * remove sacked bytes delivered */
1467 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1469 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1470 - tc->sack_sb.last_bytes_delivered;
1471 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1472 tc->snd_rxt_bytes -= rxt_delivered;
1476 /* Apparently all retransmitted holes have been acked */
1477 tc->snd_rxt_bytes = 0;
1478 tc->sack_sb.high_rxt = tc->snd_una;
1483 tcp_fastrecovery_first_on (tc);
1484 /* Reuse last bytes delivered to track total bytes acked */
1485 tc->sack_sb.last_bytes_delivered += tc->bytes_acked;
1486 if (tc->snd_rxt_bytes > tc->bytes_acked)
1487 tc->snd_rxt_bytes -= tc->bytes_acked;
1489 tc->snd_rxt_bytes = 0;
1492 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1495 * Since this was a partial ack, try to retransmit some more data
1497 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1501 * Process incoming ACK
1504 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1505 tcp_header_t * th, u32 * error)
1507 u32 prev_snd_wnd, prev_snd_una;
1510 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1512 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1513 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1515 /* When we entered recovery, we reset snd_nxt to snd_una. Seems peer
1516 * still has the data so accept the ack */
1517 if (tcp_in_recovery (tc)
1518 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_congestion))
1520 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1521 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
1522 tc->snd_una_max = tc->snd_nxt;
1526 /* If we have outstanding data and this is within the window, accept it,
1527 * probably retransmit has timed out. Otherwise ACK segment and then
1529 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1531 tcp_program_ack (wrk, tc);
1532 *error = TCP_ERROR_ACK_FUTURE;
1533 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1534 vnet_buffer (b)->tcp.ack_number);
1538 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1539 vnet_buffer (b)->tcp.ack_number);
1541 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1544 /* If old ACK, probably it's an old dupack */
1545 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1547 *error = TCP_ERROR_ACK_OLD;
1548 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1549 vnet_buffer (b)->tcp.ack_number);
1550 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1551 tcp_cc_handle_event (tc, 1);
1552 /* Don't drop yet */
1557 * Looks okay, process feedback
1560 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1561 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1563 prev_snd_wnd = tc->snd_wnd;
1564 prev_snd_una = tc->snd_una;
1565 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1566 vnet_buffer (b)->tcp.ack_number,
1567 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1568 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1569 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1570 tcp_validate_txf_size (tc, tc->bytes_acked);
1572 if (tc->bytes_acked)
1574 tcp_program_dequeue (wrk, tc);
1575 tcp_update_rtt (tc, vnet_buffer (b)->tcp.ack_number);
1578 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1581 * Check if we have congestion event
1584 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1586 tcp_cc_handle_event (tc, is_dack);
1587 if (!tcp_in_cong_recovery (tc))
1589 *error = TCP_ERROR_ACK_DUP;
1590 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1596 * Update congestion control (slow start/congestion avoidance)
1598 tcp_cc_update (tc, b);
1599 *error = TCP_ERROR_ACK_OK;
1604 tcp_sack_vector_is_sane (sack_block_t * sacks)
1607 for (i = 1; i < vec_len (sacks); i++)
1609 if (sacks[i - 1].end == sacks[i].start)
1616 * Build SACK list as per RFC2018.
1618 * Makes sure the first block contains the segment that generated the current
1619 * ACK and the following ones are the ones most recently reported in SACK
1622 * @param tc TCP connection for which the SACK list is updated
1623 * @param start Start sequence number of the newest SACK block
1624 * @param end End sequence of the newest SACK block
1627 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1629 sack_block_t *new_list = 0, *block = 0;
1632 /* If the first segment is ooo add it to the list. Last write might've moved
1633 * rcv_nxt over the first segment. */
1634 if (seq_lt (tc->rcv_nxt, start))
1636 vec_add2 (new_list, block, 1);
1637 block->start = start;
1641 /* Find the blocks still worth keeping. */
1642 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1644 /* Discard if rcv_nxt advanced beyond current block */
1645 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1648 /* Merge or drop if segment overlapped by the new segment */
1649 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1650 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1652 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1653 new_list[0].start = tc->snd_sacks[i].start;
1654 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1655 new_list[0].end = tc->snd_sacks[i].end;
1659 /* Save to new SACK list if we have space. */
1660 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1662 vec_add1 (new_list, tc->snd_sacks[i]);
1666 clib_warning ("sack discarded");
1670 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1672 /* Replace old vector with new one */
1673 vec_free (tc->snd_sacks);
1674 tc->snd_sacks = new_list;
1676 /* Segments should not 'touch' */
1677 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1681 tcp_sack_list_bytes (tcp_connection_t * tc)
1684 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1685 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1689 /** Enqueue data for delivery to application */
1691 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1694 int written, error = TCP_ERROR_ENQUEUED;
1696 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1698 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1699 1 /* queue event */ , 1);
1701 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1703 /* Update rcv_nxt */
1704 if (PREDICT_TRUE (written == data_len))
1706 tc->rcv_nxt += written;
1708 /* If more data written than expected, account for out-of-order bytes. */
1709 else if (written > data_len)
1711 tc->rcv_nxt += written;
1712 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1714 else if (written > 0)
1716 /* We've written something but FIFO is probably full now */
1717 tc->rcv_nxt += written;
1718 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1722 return TCP_ERROR_FIFO_FULL;
1725 /* Update SACK list if need be */
1726 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1728 /* Remove SACK blocks that have been delivered */
1729 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1735 /** Enqueue out-of-order data */
1737 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1740 stream_session_t *s0;
1743 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1746 /* Enqueue out-of-order data with relative offset */
1747 rv = session_enqueue_stream_connection (&tc->connection, b,
1748 vnet_buffer (b)->tcp.seq_number -
1749 tc->rcv_nxt, 0 /* queue event */ ,
1752 /* Nothing written */
1755 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1756 return TCP_ERROR_FIFO_FULL;
1759 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1761 /* Update SACK list if in use */
1762 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1764 ooo_segment_t *newest;
1767 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1769 /* Get the newest segment from the fifo */
1770 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1773 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1774 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1775 start = tc->rcv_nxt + offset;
1776 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1777 tcp_update_sack_list (tc, start, end);
1778 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1779 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1783 return TCP_ERROR_ENQUEUED_OOO;
1787 * Check if ACK could be delayed. If ack can be delayed, it should return
1788 * true for a full frame. If we're always acking return 0.
1791 tcp_can_delack (tcp_connection_t * tc)
1793 /* Send ack if ... */
1795 /* just sent a rcv wnd 0 */
1796 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1797 /* constrained to send ack */
1798 || (tc->flags & TCP_CONN_SNDACK) != 0
1799 /* we're almost out of tx wnd */
1800 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1807 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1809 u32 discard, first = b->current_length;
1810 vlib_main_t *vm = vlib_get_main ();
1812 /* Handle multi-buffer segments */
1813 if (n_bytes_to_drop > b->current_length)
1815 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1819 discard = clib_min (n_bytes_to_drop, b->current_length);
1820 vlib_buffer_advance (b, discard);
1821 b = vlib_get_buffer (vm, b->next_buffer);
1822 n_bytes_to_drop -= discard;
1824 while (n_bytes_to_drop);
1825 if (n_bytes_to_drop > first)
1826 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1829 vlib_buffer_advance (b, n_bytes_to_drop);
1830 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1835 * Receive buffer for connection and handle acks
1837 * It handles both in order or out-of-order data.
1840 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1843 u32 error, n_bytes_to_drop, n_data_bytes;
1845 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1846 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1847 ASSERT (n_data_bytes);
1849 /* Handle out-of-order data */
1850 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1852 /* Old sequence numbers allowed through because they overlapped
1854 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1856 /* Completely in the past (possible retransmit). Ack
1857 * retransmissions since we may not have any data to send */
1858 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1860 tcp_program_ack (wrk, tc);
1861 error = TCP_ERROR_SEGMENT_OLD;
1865 /* Chop off the bytes in the past and see if what is left
1866 * can be enqueued in order */
1867 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1868 n_data_bytes -= n_bytes_to_drop;
1869 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1870 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1872 error = TCP_ERROR_SEGMENT_OLD;
1878 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1879 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1880 tcp_program_dupack (wrk, tc);
1881 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1887 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1888 * segments can be enqueued after fifo tail offset changes. */
1889 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1890 if (tcp_can_delack (tc))
1892 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1893 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1897 tcp_program_ack (wrk, tc);
1905 tcp_header_t tcp_header;
1906 tcp_connection_t tcp_connection;
1910 format_tcp_rx_trace (u8 * s, va_list * args)
1912 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1913 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1914 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1915 u32 indent = format_get_indent (s);
1917 s = format (s, "%U\n%U%U",
1918 format_tcp_header, &t->tcp_header, 128,
1919 format_white_space, indent,
1920 format_tcp_connection, &t->tcp_connection, 1);
1926 format_tcp_rx_trace_short (u8 * s, va_list * args)
1928 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1929 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1930 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1932 s = format (s, "%d -> %d (%U)",
1933 clib_net_to_host_u16 (t->tcp_header.dst_port),
1934 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
1935 t->tcp_connection.state);
1941 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1942 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1946 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1950 th0 = tcp_buffer_hdr (b0);
1952 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1956 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
1957 vlib_frame_t * frame, u8 is_ip4)
1961 n_left = frame->n_vectors;
1962 from = vlib_frame_vector_args (frame);
1966 tcp_connection_t *tc0;
1973 b0 = vlib_get_buffer (vm, bi0);
1975 if (b0->flags & VLIB_BUFFER_IS_TRACED)
1977 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1978 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1980 th0 = tcp_buffer_hdr (b0);
1981 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1990 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
1991 u8 is_ip4, u32 evt, u32 val)
1994 vlib_node_increment_counter (vm, tcp4_node, evt, val);
1996 vlib_node_increment_counter (vm, tcp6_node, evt, val);
1999 #define tcp_maybe_inc_counter(node_id, err, count) \
2001 if (next0 != tcp_next_drop (is_ip4)) \
2002 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2003 tcp6_##node_id##_node.index, is_ip4, err, \
2006 #define tcp_inc_counter(node_id, err, count) \
2007 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2008 tcp6_##node_id##_node.index, is_ip4, \
2010 #define tcp_maybe_inc_err_counter(cnts, err) \
2012 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2014 #define tcp_inc_err_counter(cnts, err, val) \
2018 #define tcp_store_err_counters(node_id, cnts) \
2021 for (i = 0; i < TCP_N_ERROR; i++) \
2023 tcp_inc_counter(node_id, i, cnts[i]); \
2028 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2029 vlib_frame_t * frame, int is_ip4)
2031 u32 thread_index = vm->thread_index, errors = 0;
2032 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2033 u32 n_left_from, *from, *first_buffer;
2034 u16 err_counters[TCP_N_ERROR] = { 0 };
2037 if (node->flags & VLIB_NODE_FLAG_TRACE)
2038 tcp_established_trace_frame (vm, node, frame, is_ip4);
2040 first_buffer = from = vlib_frame_vector_args (frame);
2041 n_left_from = frame->n_vectors;
2043 while (n_left_from > 0)
2045 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2047 tcp_header_t *th0 = 0;
2048 tcp_connection_t *tc0;
2050 if (n_left_from > 1)
2053 pb = vlib_get_buffer (vm, from[1]);
2054 vlib_prefetch_buffer_header (pb, LOAD);
2055 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2062 b0 = vlib_get_buffer (vm, bi0);
2063 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2066 if (PREDICT_FALSE (tc0 == 0))
2068 error0 = TCP_ERROR_INVALID_CONNECTION;
2072 th0 = tcp_buffer_hdr (b0);
2073 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
2074 * dangling reference. */
2075 is_fin = tcp_is_fin (th0);
2077 /* SYNs, FINs and data consume sequence numbers */
2078 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2079 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
2081 /* TODO header prediction fast path */
2083 /* 1-4: check SEQ, RST, SYN */
2084 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2086 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2090 /* 5: check the ACK field */
2091 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2094 /* 6: check the URG bit TODO */
2096 /* 7: process the segment text */
2097 if (vnet_buffer (b0)->tcp.data_len)
2098 error0 = tcp_segment_rcv (wrk, tc0, b0);
2100 /* 8: check the FIN bit */
2101 if (PREDICT_FALSE (is_fin))
2103 /* Enter CLOSE-WAIT and notify session. To avoid lingering
2104 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
2105 /* Account for the FIN if nothing else was received */
2106 if (vnet_buffer (b0)->tcp.data_len == 0)
2108 tcp_program_ack (wrk, tc0);
2109 tc0->state = TCP_STATE_CLOSE_WAIT;
2110 stream_session_disconnect_notify (&tc0->connection);
2111 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
2112 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2113 error0 = TCP_ERROR_FIN_RCVD;
2117 tcp_inc_err_counter (err_counters, error0, 1);
2120 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2122 err_counters[TCP_ERROR_EVENT_FIFO_FULL] = errors;
2123 tcp_store_err_counters (established, err_counters);
2124 tcp_handle_postponed_dequeues (wrk);
2125 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2127 return frame->n_vectors;
2131 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2132 vlib_frame_t * from_frame)
2134 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2138 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2139 vlib_frame_t * from_frame)
2141 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2145 VLIB_REGISTER_NODE (tcp4_established_node) =
2147 .function = tcp4_established,
2148 .name = "tcp4-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,
2164 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
2167 VLIB_REGISTER_NODE (tcp6_established_node) =
2169 .function = tcp6_established,
2170 .name = "tcp6-established",
2171 /* Takes a vector of packets. */
2172 .vector_size = sizeof (u32),
2173 .n_errors = TCP_N_ERROR,
2174 .error_strings = tcp_error_strings,
2175 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2178 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2179 foreach_tcp_state_next
2182 .format_trace = format_tcp_rx_trace_short,
2187 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
2189 vlib_node_registration_t tcp4_syn_sent_node;
2190 vlib_node_registration_t tcp6_syn_sent_node;
2193 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2195 transport_connection_t *tmp = 0;
2202 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2205 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2206 && (tc->state == TCP_STATE_LISTEN
2207 || tc->c_rmt_port == hdr->src_port));
2211 handle = session_lookup_half_open_handle (&tc->connection);
2212 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2213 tc->c_proto, tc->c_is_ip4);
2217 if (tmp->lcl_port == hdr->dst_port
2218 && tmp->rmt_port == hdr->src_port)
2220 TCP_DBG ("half-open is valid!");
2228 * Lookup transport connection
2230 static tcp_connection_t *
2231 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2235 transport_connection_t *tconn;
2236 tcp_connection_t *tc;
2241 ip4 = vlib_buffer_get_current (b);
2242 tcp = ip4_next_header (ip4);
2243 tconn = session_lookup_connection_wt4 (fib_index,
2248 TRANSPORT_PROTO_TCP,
2249 thread_index, &is_filtered);
2250 tc = tcp_get_connection_from_transport (tconn);
2251 ASSERT (tcp_lookup_is_valid (tc, tcp));
2256 ip6 = vlib_buffer_get_current (b);
2257 tcp = ip6_next_header (ip6);
2258 tconn = session_lookup_connection_wt6 (fib_index,
2263 TRANSPORT_PROTO_TCP,
2264 thread_index, &is_filtered);
2265 tc = tcp_get_connection_from_transport (tconn);
2266 ASSERT (tcp_lookup_is_valid (tc, tcp));
2272 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2273 vlib_frame_t * from_frame, int is_ip4)
2275 tcp_main_t *tm = vnet_get_tcp_main ();
2276 u32 n_left_from, *from, *first_buffer, errors = 0;
2277 u32 my_thread_index = vm->thread_index;
2278 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2280 from = first_buffer = vlib_frame_vector_args (from_frame);
2281 n_left_from = from_frame->n_vectors;
2283 while (n_left_from > 0)
2285 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2286 tcp_connection_t *tc0, *new_tc0;
2287 tcp_header_t *tcp0 = 0;
2295 b0 = vlib_get_buffer (vm, bi0);
2297 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2298 if (PREDICT_FALSE (tc0 == 0))
2300 error0 = TCP_ERROR_INVALID_CONNECTION;
2304 /* Half-open completed recently but the connection was't removed
2305 * yet by the owning thread */
2306 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2308 /* Make sure the connection actually exists */
2309 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2310 my_thread_index, is_ip4));
2314 ack0 = vnet_buffer (b0)->tcp.ack_number;
2315 seq0 = vnet_buffer (b0)->tcp.seq_number;
2316 tcp0 = tcp_buffer_hdr (b0);
2318 /* Crude check to see if the connection handle does not match
2319 * the packet. Probably connection just switched to established */
2320 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2321 || tcp0->src_port != tc0->c_rmt_port))
2323 error0 = TCP_ERROR_INVALID_CONNECTION;
2327 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2328 && !tcp_syn (tcp0)))
2330 error0 = TCP_ERROR_SEGMENT_INVALID;
2334 /* SYNs, FINs and data consume sequence numbers */
2335 vnet_buffer (b0)->tcp.seq_end =
2336 seq0 + tcp_is_syn (tcp0) + tcp_is_fin (tcp0) +
2337 vnet_buffer (b0)->tcp.data_len;
2340 * 1. check the ACK bit
2344 * If the ACK bit is set
2345 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2346 * the RST bit is set, if so drop the segment and return)
2347 * <SEQ=SEG.ACK><CTL=RST>
2348 * and discard the segment. Return.
2349 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2353 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2355 if (!tcp_rst (tcp0))
2356 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2357 error0 = TCP_ERROR_RCV_WND;
2361 /* Make sure ACK is valid */
2362 if (seq_gt (tc0->snd_una, ack0))
2364 error0 = TCP_ERROR_ACK_INVALID;
2370 * 2. check the RST bit
2375 /* If ACK is acceptable, signal client that peer is not
2376 * willing to accept connection and drop connection*/
2378 tcp_connection_reset (tc0);
2379 error0 = TCP_ERROR_RST_RCVD;
2384 * 3. check the security and precedence (skipped)
2388 * 4. check the SYN bit
2391 /* No SYN flag. Drop. */
2392 if (!tcp_syn (tcp0))
2394 clib_warning ("not synack");
2395 error0 = TCP_ERROR_SEGMENT_INVALID;
2400 if (tcp_options_parse (tcp0, &tc0->rcv_opts))
2402 clib_warning ("options parse fail");
2403 error0 = TCP_ERROR_OPTIONS;
2407 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2408 * current thread pool. */
2409 pool_get (tm->connections[my_thread_index], new_tc0);
2410 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
2411 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2412 new_tc0->c_thread_index = my_thread_index;
2413 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2414 new_tc0->irs = seq0;
2415 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
2416 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2417 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2419 /* If this is not the owning thread, wait for syn retransmit to
2420 * expire and cleanup then */
2421 if (tcp_half_open_connection_cleanup (tc0))
2422 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2424 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2426 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2427 new_tc0->tsval_recent_age = tcp_time_now ();
2430 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2431 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2433 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2434 << new_tc0->snd_wscale;
2435 new_tc0->snd_wl1 = seq0;
2436 new_tc0->snd_wl2 = ack0;
2438 tcp_connection_init_vars (new_tc0);
2440 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2441 if (PREDICT_TRUE (tcp_ack (tcp0)))
2443 /* Our SYN is ACKed: we have iss < ack = snd_una */
2445 /* TODO Dequeue acknowledged segments if we support Fast Open */
2446 new_tc0->snd_una = ack0;
2447 new_tc0->state = TCP_STATE_ESTABLISHED;
2449 /* Make sure las is initialized for the wnd computation */
2450 new_tc0->rcv_las = new_tc0->rcv_nxt;
2452 /* Notify app that we have connection. If session layer can't
2453 * allocate session send reset */
2454 if (session_stream_connect_notify (&new_tc0->connection, 0))
2456 clib_warning ("connect notify fail");
2457 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2458 tcp_connection_cleanup (new_tc0);
2462 new_tc0->tx_fifo_size =
2463 transport_tx_fifo_size (&new_tc0->connection);
2464 /* Update rtt with the syn-ack sample */
2465 tcp_estimate_initial_rtt (new_tc0);
2466 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2467 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2469 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2472 new_tc0->state = TCP_STATE_SYN_RCVD;
2474 /* Notify app that we have connection */
2475 if (session_stream_connect_notify (&new_tc0->connection, 0))
2477 tcp_connection_cleanup (new_tc0);
2478 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2479 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2483 new_tc0->tx_fifo_size =
2484 transport_tx_fifo_size (&new_tc0->connection);
2485 new_tc0->rtt_ts = 0;
2486 tcp_init_snd_vars (new_tc0);
2487 tcp_send_synack (new_tc0);
2488 error0 = TCP_ERROR_SYNS_RCVD;
2492 /* Read data, if any */
2493 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2495 clib_warning ("rcvd data in syn-sent");
2496 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2497 if (error0 == TCP_ERROR_ACK_OK)
2498 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2502 tcp_program_ack (wrk, new_tc0);
2507 tcp_inc_counter (syn_sent, error0, 1);
2508 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2510 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2511 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2512 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
2516 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2518 tcp_inc_counter (syn_sent, TCP_ERROR_EVENT_FIFO_FULL, errors);
2519 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2521 return from_frame->n_vectors;
2525 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2526 vlib_frame_t * from_frame)
2528 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2532 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2533 vlib_frame_t * from_frame)
2535 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2539 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2541 .function = tcp4_syn_sent,
2542 .name = "tcp4-syn-sent",
2543 /* Takes a vector of packets. */
2544 .vector_size = sizeof (u32),
2545 .n_errors = TCP_N_ERROR,
2546 .error_strings = tcp_error_strings,
2547 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2550 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2551 foreach_tcp_state_next
2554 .format_trace = format_tcp_rx_trace_short,
2558 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2561 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2563 .function = tcp6_syn_sent_rcv,
2564 .name = "tcp6-syn-sent",
2565 /* Takes a vector of packets. */
2566 .vector_size = sizeof (u32),
2567 .n_errors = TCP_N_ERROR,
2568 .error_strings = tcp_error_strings,
2569 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2572 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2573 foreach_tcp_state_next
2576 .format_trace = format_tcp_rx_trace_short,
2580 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2582 vlib_node_registration_t tcp4_rcv_process_node;
2583 vlib_node_registration_t tcp6_rcv_process_node;
2586 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2587 * as per RFC793 p. 64
2590 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2591 vlib_frame_t * from_frame, int is_ip4)
2593 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2594 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2595 u32 n_left_from, *from;
2597 from = first_buffer = vlib_frame_vector_args (from_frame);
2598 n_left_from = from_frame->n_vectors;
2600 while (n_left_from > 0)
2602 u32 bi0, error0 = TCP_ERROR_NONE;
2603 tcp_header_t *tcp0 = 0;
2604 tcp_connection_t *tc0;
2612 b0 = vlib_get_buffer (vm, bi0);
2613 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2615 if (PREDICT_FALSE (tc0 == 0))
2617 error0 = TCP_ERROR_INVALID_CONNECTION;
2621 tcp0 = tcp_buffer_hdr (b0);
2622 is_fin0 = tcp_is_fin (tcp0);
2624 /* SYNs, FINs and data consume sequence numbers */
2625 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2626 + tcp_is_syn (tcp0) + is_fin0 + vnet_buffer (b0)->tcp.data_len;
2630 tcp_connection_t *tmp;
2631 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2633 if (tmp->state != tc0->state)
2635 clib_warning ("state changed");
2641 * Special treatment for CLOSED
2643 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2645 error0 = TCP_ERROR_CONNECTION_CLOSED;
2650 * For all other states (except LISTEN)
2653 /* 1-4: check SEQ, RST, SYN */
2654 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2657 /* 5: check the ACK field */
2660 case TCP_STATE_SYN_RCVD:
2662 * If the segment acknowledgment is not acceptable, form a
2664 * <SEQ=SEG.ACK><CTL=RST>
2667 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2669 TCP_DBG ("connection not accepted");
2670 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2671 error0 = TCP_ERROR_ACK_INVALID;
2675 /* Update rtt and rto */
2676 tcp_estimate_initial_rtt (tc0);
2678 /* Switch state to ESTABLISHED */
2679 tc0->state = TCP_STATE_ESTABLISHED;
2680 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2682 /* Initialize session variables */
2683 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2684 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2685 << tc0->rcv_opts.wscale;
2686 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2687 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2689 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2690 tcp_retransmit_timer_reset (tc0);
2691 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2692 stream_session_accept_notify (&tc0->connection);
2693 error0 = TCP_ERROR_ACK_OK;
2695 case TCP_STATE_ESTABLISHED:
2696 /* We can get packets in established state here because they
2697 * were enqueued before state change */
2698 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2702 case TCP_STATE_FIN_WAIT_1:
2703 /* In addition to the processing for the ESTABLISHED state, if
2704 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2705 * continue processing in that state. */
2706 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2709 /* Still have to send the FIN */
2710 if (tc0->flags & TCP_CONN_FINPNDG)
2712 /* TX fifo finally drained */
2713 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2716 /* If FIN is ACKed */
2717 else if (tc0->snd_una == tc0->snd_una_max)
2719 tc0->state = TCP_STATE_FIN_WAIT_2;
2720 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2722 /* Stop all retransmit timers because we have nothing more
2723 * to send. Enable waitclose though because we're willing to
2724 * wait for peer's FIN but not indefinitely. */
2725 tcp_connection_timers_reset (tc0);
2726 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2728 /* Don't try to deq the FIN acked */
2729 if (tc0->burst_acked > 1)
2730 stream_session_dequeue_drop (&tc0->connection,
2731 tc0->burst_acked - 1);
2732 tc0->burst_acked = 0;
2735 case TCP_STATE_FIN_WAIT_2:
2736 /* In addition to the processing for the ESTABLISHED state, if
2737 * the retransmission queue is empty, the user's CLOSE can be
2738 * acknowledged ("ok") but do not delete the TCB. */
2739 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2741 tc0->burst_acked = 0;
2743 case TCP_STATE_CLOSE_WAIT:
2744 /* Do the same processing as for the ESTABLISHED state. */
2745 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2748 if (tc0->flags & TCP_CONN_FINPNDG)
2750 /* TX fifo finally drained */
2751 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2754 tcp_connection_timers_reset (tc0);
2755 tc0->state = TCP_STATE_LAST_ACK;
2756 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2760 case TCP_STATE_CLOSING:
2761 /* In addition to the processing for the ESTABLISHED state, if
2762 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2763 * otherwise ignore the segment. */
2764 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2767 tc0->state = TCP_STATE_TIME_WAIT;
2768 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2769 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2773 case TCP_STATE_LAST_ACK:
2774 /* The only thing that [should] arrive in this state is an
2775 * acknowledgment of our FIN. If our FIN is now acknowledged,
2776 * delete the TCB, enter the CLOSED state, and return. */
2778 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2780 error0 = TCP_ERROR_ACK_INVALID;
2783 error0 = TCP_ERROR_ACK_OK;
2784 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2785 /* Apparently our ACK for the peer's FIN was lost */
2786 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2792 tc0->state = TCP_STATE_CLOSED;
2793 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2795 /* Don't free the connection from the data path since
2796 * we can't ensure that we have no packets already enqueued
2797 * to output. Rely instead on the waitclose timer */
2798 tcp_connection_timers_reset (tc0);
2799 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, 1);
2804 case TCP_STATE_TIME_WAIT:
2805 /* The only thing that can arrive in this state is a
2806 * retransmission of the remote FIN. Acknowledge it, and restart
2807 * the 2 MSL timeout. */
2809 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2812 tcp_program_ack (wrk, tc0);
2813 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2821 /* 6: check the URG bit TODO */
2823 /* 7: process the segment text */
2826 case TCP_STATE_ESTABLISHED:
2827 case TCP_STATE_FIN_WAIT_1:
2828 case TCP_STATE_FIN_WAIT_2:
2829 if (vnet_buffer (b0)->tcp.data_len)
2830 error0 = tcp_segment_rcv (wrk, tc0, b0);
2834 case TCP_STATE_CLOSE_WAIT:
2835 case TCP_STATE_CLOSING:
2836 case TCP_STATE_LAST_ACK:
2837 case TCP_STATE_TIME_WAIT:
2838 /* This should not occur, since a FIN has been received from the
2839 * remote side. Ignore the segment text. */
2843 /* 8: check the FIN bit */
2849 case TCP_STATE_ESTABLISHED:
2850 case TCP_STATE_SYN_RCVD:
2851 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2852 tcp_connection_timers_reset (tc0);
2854 stream_session_disconnect_notify (&tc0->connection);
2855 tc0->state = TCP_STATE_CLOSE_WAIT;
2856 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2858 case TCP_STATE_CLOSE_WAIT:
2859 case TCP_STATE_CLOSING:
2860 case TCP_STATE_LAST_ACK:
2863 case TCP_STATE_FIN_WAIT_1:
2864 tc0->state = TCP_STATE_CLOSING;
2865 tcp_program_ack (wrk, tc0);
2866 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2867 /* Wait for ACK but not forever */
2868 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2870 case TCP_STATE_FIN_WAIT_2:
2871 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2872 tc0->state = TCP_STATE_TIME_WAIT;
2873 tcp_connection_timers_reset (tc0);
2874 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2875 tcp_program_ack (wrk, tc0);
2876 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2878 case TCP_STATE_TIME_WAIT:
2879 /* Remain in the TIME-WAIT state. Restart the time-wait
2882 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2885 error0 = TCP_ERROR_FIN_RCVD;
2886 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2890 tcp_inc_counter (rcv_process, error0, 1);
2891 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2893 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2894 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2898 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2900 tcp_inc_counter (rcv_process, TCP_ERROR_EVENT_FIFO_FULL, errors);
2901 tcp_handle_postponed_dequeues (wrk);
2902 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2904 return from_frame->n_vectors;
2908 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2909 vlib_frame_t * from_frame)
2911 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2915 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2916 vlib_frame_t * from_frame)
2918 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2922 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2924 .function = tcp4_rcv_process,
2925 .name = "tcp4-rcv-process",
2926 /* Takes a vector of packets. */
2927 .vector_size = sizeof (u32),
2928 .n_errors = TCP_N_ERROR,
2929 .error_strings = tcp_error_strings,
2930 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2933 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2934 foreach_tcp_state_next
2937 .format_trace = format_tcp_rx_trace_short,
2941 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2944 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2946 .function = tcp6_rcv_process,
2947 .name = "tcp6-rcv-process",
2948 /* Takes a vector of packets. */
2949 .vector_size = sizeof (u32),
2950 .n_errors = TCP_N_ERROR,
2951 .error_strings = tcp_error_strings,
2952 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2955 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2956 foreach_tcp_state_next
2959 .format_trace = format_tcp_rx_trace_short,
2963 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2965 vlib_node_registration_t tcp4_listen_node;
2966 vlib_node_registration_t tcp6_listen_node;
2969 * LISTEN state processing as per RFC 793 p. 65
2972 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2973 vlib_frame_t * from_frame, int is_ip4)
2975 u32 n_left_from, *from, n_syns = 0, *first_buffer;
2976 u32 my_thread_index = vm->thread_index;
2978 from = first_buffer = vlib_frame_vector_args (from_frame);
2979 n_left_from = from_frame->n_vectors;
2981 while (n_left_from > 0)
2986 tcp_header_t *th0 = 0;
2987 tcp_connection_t *lc0;
2990 tcp_connection_t *child0;
2991 u32 error0 = TCP_ERROR_NONE;
2997 b0 = vlib_get_buffer (vm, bi0);
2998 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3002 ip40 = vlib_buffer_get_current (b0);
3003 th0 = ip4_next_header (ip40);
3007 ip60 = vlib_buffer_get_current (b0);
3008 th0 = ip6_next_header (ip60);
3011 /* Create child session. For syn-flood protection use filter */
3013 /* 1. first check for an RST: handled in dispatch */
3014 /* if (tcp_rst (th0))
3018 /* 2. second check for an ACK: handled in dispatch */
3019 /* if (tcp_ack (th0))
3021 tcp_send_reset (b0, is_ip4);
3026 /* 3. check for a SYN (did that already) */
3028 /* Make sure connection wasn't just created */
3029 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3031 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3033 error0 = TCP_ERROR_CREATE_EXISTS;
3037 /* Create child session and send SYN-ACK */
3038 child0 = tcp_connection_new (my_thread_index);
3039 child0->c_lcl_port = th0->dst_port;
3040 child0->c_rmt_port = th0->src_port;
3041 child0->c_is_ip4 = is_ip4;
3042 child0->state = TCP_STATE_SYN_RCVD;
3043 child0->c_fib_index = lc0->c_fib_index;
3047 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3048 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3052 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
3053 sizeof (ip6_address_t));
3054 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
3055 sizeof (ip6_address_t));
3058 if (tcp_options_parse (th0, &child0->rcv_opts))
3060 clib_warning ("options parse fail");
3064 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3065 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3066 child0->rcv_las = child0->rcv_nxt;
3067 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3069 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3070 * segments are used to initialize PAWS. */
3071 if (tcp_opts_tstamp (&child0->rcv_opts))
3073 child0->tsval_recent = child0->rcv_opts.tsval;
3074 child0->tsval_recent_age = tcp_time_now ();
3077 if (tcp_opts_wscale (&child0->rcv_opts))
3078 child0->snd_wscale = child0->rcv_opts.wscale;
3080 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3081 << child0->snd_wscale;
3082 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3083 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3085 tcp_connection_init_vars (child0);
3086 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
3088 if (stream_session_accept (&child0->connection, lc0->c_s_index,
3091 clib_warning ("session accept fail");
3092 tcp_connection_cleanup (child0);
3093 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3097 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3098 tcp_send_synack (child0);
3099 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
3103 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3105 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3106 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3107 clib_memcpy (&t0->tcp_connection, lc0, sizeof (t0->tcp_connection));
3110 n_syns += (error0 == TCP_ERROR_NONE);
3113 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3114 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3116 return from_frame->n_vectors;
3120 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3121 vlib_frame_t * from_frame)
3123 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3127 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3128 vlib_frame_t * from_frame)
3130 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3134 VLIB_REGISTER_NODE (tcp4_listen_node) =
3136 .function = tcp4_listen,
3137 .name = "tcp4-listen",
3138 /* Takes a vector of packets. */
3139 .vector_size = sizeof (u32),
3140 .n_errors = TCP_N_ERROR,
3141 .error_strings = tcp_error_strings,
3142 .n_next_nodes = TCP_LISTEN_N_NEXT,
3145 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3146 foreach_tcp_state_next
3149 .format_trace = format_tcp_rx_trace_short,
3153 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
3156 VLIB_REGISTER_NODE (tcp6_listen_node) =
3158 .function = tcp6_listen,
3159 .name = "tcp6-listen",
3160 /* Takes a vector of packets. */
3161 .vector_size = sizeof (u32),
3162 .n_errors = TCP_N_ERROR,
3163 .error_strings = tcp_error_strings,
3164 .n_next_nodes = TCP_LISTEN_N_NEXT,
3167 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3168 foreach_tcp_state_next
3171 .format_trace = format_tcp_rx_trace_short,
3175 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
3177 vlib_node_registration_t tcp4_input_node;
3178 vlib_node_registration_t tcp6_input_node;
3180 typedef enum _tcp_input_next
3182 TCP_INPUT_NEXT_DROP,
3183 TCP_INPUT_NEXT_LISTEN,
3184 TCP_INPUT_NEXT_RCV_PROCESS,
3185 TCP_INPUT_NEXT_SYN_SENT,
3186 TCP_INPUT_NEXT_ESTABLISHED,
3187 TCP_INPUT_NEXT_RESET,
3188 TCP_INPUT_NEXT_PUNT,
3192 #define foreach_tcp4_input_next \
3193 _ (DROP, "ip4-drop") \
3194 _ (LISTEN, "tcp4-listen") \
3195 _ (RCV_PROCESS, "tcp4-rcv-process") \
3196 _ (SYN_SENT, "tcp4-syn-sent") \
3197 _ (ESTABLISHED, "tcp4-established") \
3198 _ (RESET, "tcp4-reset") \
3199 _ (PUNT, "ip4-punt")
3201 #define foreach_tcp6_input_next \
3202 _ (DROP, "ip6-drop") \
3203 _ (LISTEN, "tcp6-listen") \
3204 _ (RCV_PROCESS, "tcp6-rcv-process") \
3205 _ (SYN_SENT, "tcp6-syn-sent") \
3206 _ (ESTABLISHED, "tcp6-established") \
3207 _ (RESET, "tcp6-reset") \
3208 _ (PUNT, "ip6-punt")
3210 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3213 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3214 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3216 tcp_connection_t *tc;
3221 for (i = 0; i < n_bufs; i++)
3223 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3225 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3226 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3228 tcp = vlib_buffer_get_current (bs[i]);
3229 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3235 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3237 if (*error == TCP_ERROR_FILTERED)
3239 *next = TCP_INPUT_NEXT_DROP;
3241 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3243 *next = TCP_INPUT_NEXT_PUNT;
3244 *error = TCP_ERROR_PUNT;
3248 *next = TCP_INPUT_NEXT_RESET;
3249 *error = TCP_ERROR_NO_LISTENER;
3253 static inline tcp_connection_t *
3254 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3257 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3258 int n_advance_bytes, n_data_bytes;
3259 transport_connection_t *tc;
3265 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3266 tcp = ip4_next_header (ip4);
3267 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3268 n_advance_bytes = (ip4_header_bytes (ip4) + tcp_header_bytes (tcp));
3269 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3271 /* Length check. Checksum computed by ipx_local no need to compute again */
3272 if (PREDICT_FALSE (n_advance_bytes < 0))
3274 *error = TCP_ERROR_LENGTH;
3278 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3279 &ip4->src_address, tcp->dst_port,
3280 tcp->src_port, TRANSPORT_PROTO_TCP,
3281 thread_index, &is_filtered);
3285 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3286 tcp = ip6_next_header (ip6);
3287 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3288 n_advance_bytes = tcp_header_bytes (tcp);
3289 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3291 n_advance_bytes += sizeof (ip6[0]);
3293 if (PREDICT_FALSE (n_advance_bytes < 0))
3295 *error = TCP_ERROR_LENGTH;
3299 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3300 &ip6->src_address, tcp->dst_port,
3301 tcp->src_port, TRANSPORT_PROTO_TCP,
3302 thread_index, &is_filtered);
3305 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3306 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3307 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3308 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3309 vnet_buffer (b)->tcp.flags = 0;
3311 *error = is_filtered ? TCP_ERROR_FILTERED : *error;
3313 return tcp_get_connection_from_transport (tc);
3317 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3318 vlib_buffer_t * b, u16 * next, u32 * error)
3323 tcp = tcp_buffer_hdr (b);
3324 flags = tcp->flags & filter_flags;
3325 *next = tm->dispatch_table[tc->state][flags].next;
3326 *error = tm->dispatch_table[tc->state][flags].error;
3328 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3329 || *next == TCP_INPUT_NEXT_RESET))
3331 /* Overload tcp flags to store state */
3332 tcp_state_t state = tc->state;
3333 vnet_buffer (b)->tcp.flags = tc->state;
3335 if (*error == TCP_ERROR_DISPATCH)
3336 clib_warning ("disp error state %U flags %U", format_tcp_state,
3337 state, format_tcp_flags, (int) flags);
3342 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3343 vlib_frame_t * frame, int is_ip4)
3345 u32 n_left_from, *from, thread_index = vm->thread_index;
3346 tcp_main_t *tm = vnet_get_tcp_main ();
3347 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3348 u16 nexts[VLIB_FRAME_SIZE], *next;
3350 tcp_set_time_now (tcp_get_worker (thread_index));
3352 from = vlib_frame_vector_args (frame);
3353 n_left_from = frame->n_vectors;
3354 vlib_get_buffers (vm, from, bufs, n_left_from);
3359 while (n_left_from >= 4)
3361 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3362 tcp_connection_t *tc0, *tc1;
3365 vlib_prefetch_buffer_header (b[2], STORE);
3366 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3368 vlib_prefetch_buffer_header (b[3], STORE);
3369 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3372 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3374 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3375 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4);
3377 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3379 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3380 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3382 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3383 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3385 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3386 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3390 if (PREDICT_TRUE (tc0 != 0))
3392 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3393 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3394 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3397 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3399 if (PREDICT_TRUE (tc1 != 0))
3401 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3402 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3403 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3406 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3413 while (n_left_from > 0)
3415 tcp_connection_t *tc0;
3416 u32 error0 = TCP_ERROR_NO_LISTENER;
3418 if (n_left_from > 1)
3420 vlib_prefetch_buffer_header (b[1], STORE);
3421 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3424 next[0] = TCP_INPUT_NEXT_DROP;
3425 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3426 if (PREDICT_TRUE (tc0 != 0))
3428 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3429 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3430 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3433 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3440 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3441 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3443 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3444 return frame->n_vectors;
3448 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3449 vlib_frame_t * from_frame)
3451 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3455 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3456 vlib_frame_t * from_frame)
3458 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3462 VLIB_REGISTER_NODE (tcp4_input_node) =
3464 .function = tcp4_input,
3465 .name = "tcp4-input",
3466 /* Takes a vector of packets. */
3467 .vector_size = sizeof (u32),
3468 .n_errors = TCP_N_ERROR,
3469 .error_strings = tcp_error_strings,
3470 .n_next_nodes = TCP_INPUT_N_NEXT,
3473 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3474 foreach_tcp4_input_next
3477 .format_buffer = format_tcp_header,
3478 .format_trace = format_tcp_rx_trace,
3482 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3485 VLIB_REGISTER_NODE (tcp6_input_node) =
3487 .function = tcp6_input,
3488 .name = "tcp6-input",
3489 /* Takes a vector of packets. */
3490 .vector_size = sizeof (u32),
3491 .n_errors = TCP_N_ERROR,
3492 .error_strings = tcp_error_strings,
3493 .n_next_nodes = TCP_INPUT_N_NEXT,
3496 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3497 foreach_tcp6_input_next
3500 .format_buffer = format_tcp_header,
3501 .format_trace = format_tcp_rx_trace,
3505 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3508 tcp_dispatch_table_init (tcp_main_t * tm)
3511 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3512 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3514 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3515 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3518 #define _(t,f,n,e) \
3520 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3521 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3524 /* SYNs for new connections -> tcp-listen. */
3525 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3526 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3527 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_RST_RCVD);
3528 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3530 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3531 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3532 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3533 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3535 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3536 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3538 /* SYN-ACK for a SYN */
3539 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3541 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3542 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3543 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3545 /* ACK for for established connection -> tcp-established. */
3546 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3547 /* FIN for for established connection -> tcp-established. */
3548 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3549 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3551 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3552 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3554 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3555 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3557 /* ACK or FIN-ACK to our FIN */
3558 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3559 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3561 /* FIN in reply to our FIN from the other side */
3562 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3563 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3564 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3565 /* FIN confirming that the peer (app) has closed */
3566 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3567 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3568 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3570 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3571 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3573 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3574 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3575 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3577 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3578 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3579 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3580 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3582 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3583 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3584 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3585 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3586 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3587 TCP_ERROR_CONNECTION_CLOSED);
3591 static clib_error_t *
3592 tcp_input_init (vlib_main_t * vm)
3594 clib_error_t *error = 0;
3595 tcp_main_t *tm = vnet_get_tcp_main ();
3597 if ((error = vlib_call_init_function (vm, tcp_init)))
3600 /* Initialize dispatch table. */
3601 tcp_dispatch_table_init (tm);
3606 VLIB_INIT_FUNCTION (tcp_input_init);
3609 * fd.io coding-style-patch-verification: ON
3612 * eval: (c-set-style "gnu")