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 (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1997 th0 = tcp_buffer_hdr (b0);
1999 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2003 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2004 vlib_frame_t * frame, u8 is_ip4)
2008 n_left = frame->n_vectors;
2009 from = vlib_frame_vector_args (frame);
2013 tcp_connection_t *tc0;
2020 b0 = vlib_get_buffer (vm, bi0);
2022 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2024 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2025 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2027 th0 = tcp_buffer_hdr (b0);
2028 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2037 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2038 u8 is_ip4, u32 evt, u32 val)
2041 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2043 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2046 #define tcp_maybe_inc_counter(node_id, err, count) \
2048 if (next0 != tcp_next_drop (is_ip4)) \
2049 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2050 tcp6_##node_id##_node.index, is_ip4, err, \
2053 #define tcp_inc_counter(node_id, err, count) \
2054 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2055 tcp6_##node_id##_node.index, is_ip4, \
2057 #define tcp_maybe_inc_err_counter(cnts, err) \
2059 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2061 #define tcp_inc_err_counter(cnts, err, val) \
2065 #define tcp_store_err_counters(node_id, cnts) \
2068 for (i = 0; i < TCP_N_ERROR; i++) \
2070 tcp_inc_counter(node_id, i, cnts[i]); \
2075 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2076 vlib_frame_t * frame, int is_ip4)
2078 u32 thread_index = vm->thread_index, errors = 0;
2079 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2080 u32 n_left_from, *from, *first_buffer;
2081 u16 err_counters[TCP_N_ERROR] = { 0 };
2084 if (node->flags & VLIB_NODE_FLAG_TRACE)
2085 tcp_established_trace_frame (vm, node, frame, is_ip4);
2087 first_buffer = from = vlib_frame_vector_args (frame);
2088 n_left_from = frame->n_vectors;
2090 while (n_left_from > 0)
2092 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2094 tcp_header_t *th0 = 0;
2095 tcp_connection_t *tc0;
2097 if (n_left_from > 1)
2100 pb = vlib_get_buffer (vm, from[1]);
2101 vlib_prefetch_buffer_header (pb, LOAD);
2102 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2109 b0 = vlib_get_buffer (vm, bi0);
2110 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2113 if (PREDICT_FALSE (tc0 == 0))
2115 error0 = TCP_ERROR_INVALID_CONNECTION;
2119 th0 = tcp_buffer_hdr (b0);
2120 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
2121 * dangling reference. */
2122 is_fin = tcp_is_fin (th0);
2124 /* SYNs, FINs and data consume sequence numbers */
2125 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2126 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
2128 /* TODO header prediction fast path */
2130 /* 1-4: check SEQ, RST, SYN */
2131 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2133 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2137 /* 5: check the ACK field */
2138 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2141 /* 6: check the URG bit TODO */
2143 /* 7: process the segment text */
2144 if (vnet_buffer (b0)->tcp.data_len)
2145 error0 = tcp_segment_rcv (wrk, tc0, b0);
2147 /* 8: check the FIN bit */
2148 if (PREDICT_FALSE (is_fin))
2149 tcp_rcv_fin (wrk, tc0, b0, &error0);
2152 tcp_inc_err_counter (err_counters, error0, 1);
2155 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2157 err_counters[TCP_ERROR_EVENT_FIFO_FULL] = errors;
2158 tcp_store_err_counters (established, err_counters);
2159 tcp_handle_postponed_dequeues (wrk);
2160 tcp_handle_disconnects (wrk);
2161 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2163 return frame->n_vectors;
2167 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2168 vlib_frame_t * from_frame)
2170 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2174 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2175 vlib_frame_t * from_frame)
2177 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2181 VLIB_REGISTER_NODE (tcp4_established_node) =
2183 .function = tcp4_established,
2184 .name = "tcp4-established",
2185 /* Takes a vector of packets. */
2186 .vector_size = sizeof (u32),
2187 .n_errors = TCP_N_ERROR,
2188 .error_strings = tcp_error_strings,
2189 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2192 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2193 foreach_tcp_state_next
2196 .format_trace = format_tcp_rx_trace_short,
2200 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
2203 VLIB_REGISTER_NODE (tcp6_established_node) =
2205 .function = tcp6_established,
2206 .name = "tcp6-established",
2207 /* Takes a vector of packets. */
2208 .vector_size = sizeof (u32),
2209 .n_errors = TCP_N_ERROR,
2210 .error_strings = tcp_error_strings,
2211 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2214 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2215 foreach_tcp_state_next
2218 .format_trace = format_tcp_rx_trace_short,
2223 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
2225 vlib_node_registration_t tcp4_syn_sent_node;
2226 vlib_node_registration_t tcp6_syn_sent_node;
2229 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2231 transport_connection_t *tmp = 0;
2238 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2241 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2242 && (tc->state == TCP_STATE_LISTEN
2243 || tc->c_rmt_port == hdr->src_port));
2247 handle = session_lookup_half_open_handle (&tc->connection);
2248 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2249 tc->c_proto, tc->c_is_ip4);
2253 if (tmp->lcl_port == hdr->dst_port
2254 && tmp->rmt_port == hdr->src_port)
2256 TCP_DBG ("half-open is valid!");
2264 * Lookup transport connection
2266 static tcp_connection_t *
2267 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2271 transport_connection_t *tconn;
2272 tcp_connection_t *tc;
2277 ip4 = vlib_buffer_get_current (b);
2278 tcp = ip4_next_header (ip4);
2279 tconn = session_lookup_connection_wt4 (fib_index,
2284 TRANSPORT_PROTO_TCP,
2285 thread_index, &is_filtered);
2286 tc = tcp_get_connection_from_transport (tconn);
2287 ASSERT (tcp_lookup_is_valid (tc, tcp));
2292 ip6 = vlib_buffer_get_current (b);
2293 tcp = ip6_next_header (ip6);
2294 tconn = session_lookup_connection_wt6 (fib_index,
2299 TRANSPORT_PROTO_TCP,
2300 thread_index, &is_filtered);
2301 tc = tcp_get_connection_from_transport (tconn);
2302 ASSERT (tcp_lookup_is_valid (tc, tcp));
2308 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2309 vlib_frame_t * from_frame, int is_ip4)
2311 tcp_main_t *tm = vnet_get_tcp_main ();
2312 u32 n_left_from, *from, *first_buffer, errors = 0;
2313 u32 my_thread_index = vm->thread_index;
2314 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2316 from = first_buffer = vlib_frame_vector_args (from_frame);
2317 n_left_from = from_frame->n_vectors;
2319 while (n_left_from > 0)
2321 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2322 tcp_connection_t *tc0, *new_tc0;
2323 tcp_header_t *tcp0 = 0;
2331 b0 = vlib_get_buffer (vm, bi0);
2333 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2334 if (PREDICT_FALSE (tc0 == 0))
2336 error0 = TCP_ERROR_INVALID_CONNECTION;
2340 /* Half-open completed recently but the connection was't removed
2341 * yet by the owning thread */
2342 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2344 /* Make sure the connection actually exists */
2345 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2346 my_thread_index, is_ip4));
2350 ack0 = vnet_buffer (b0)->tcp.ack_number;
2351 seq0 = vnet_buffer (b0)->tcp.seq_number;
2352 tcp0 = tcp_buffer_hdr (b0);
2354 /* Crude check to see if the connection handle does not match
2355 * the packet. Probably connection just switched to established */
2356 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2357 || tcp0->src_port != tc0->c_rmt_port))
2359 error0 = TCP_ERROR_INVALID_CONNECTION;
2363 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2364 && !tcp_syn (tcp0)))
2366 error0 = TCP_ERROR_SEGMENT_INVALID;
2370 /* SYNs, FINs and data consume sequence numbers */
2371 vnet_buffer (b0)->tcp.seq_end =
2372 seq0 + tcp_is_syn (tcp0) + tcp_is_fin (tcp0) +
2373 vnet_buffer (b0)->tcp.data_len;
2376 * 1. check the ACK bit
2380 * If the ACK bit is set
2381 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2382 * the RST bit is set, if so drop the segment and return)
2383 * <SEQ=SEG.ACK><CTL=RST>
2384 * and discard the segment. Return.
2385 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2389 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2391 if (!tcp_rst (tcp0))
2392 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2393 error0 = TCP_ERROR_RCV_WND;
2397 /* Make sure ACK is valid */
2398 if (seq_gt (tc0->snd_una, ack0))
2400 error0 = TCP_ERROR_ACK_INVALID;
2406 * 2. check the RST bit
2411 /* If ACK is acceptable, signal client that peer is not
2412 * willing to accept connection and drop connection*/
2414 tcp_connection_reset (tc0);
2415 error0 = TCP_ERROR_RST_RCVD;
2420 * 3. check the security and precedence (skipped)
2424 * 4. check the SYN bit
2427 /* No SYN flag. Drop. */
2428 if (!tcp_syn (tcp0))
2430 clib_warning ("not synack");
2431 error0 = TCP_ERROR_SEGMENT_INVALID;
2436 if (tcp_options_parse (tcp0, &tc0->rcv_opts))
2438 clib_warning ("options parse fail");
2439 error0 = TCP_ERROR_OPTIONS;
2443 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2444 * current thread pool. */
2445 pool_get (tm->connections[my_thread_index], new_tc0);
2446 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
2447 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2448 new_tc0->c_thread_index = my_thread_index;
2449 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2450 new_tc0->irs = seq0;
2451 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
2452 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2453 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2455 /* If this is not the owning thread, wait for syn retransmit to
2456 * expire and cleanup then */
2457 if (tcp_half_open_connection_cleanup (tc0))
2458 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2460 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2462 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2463 new_tc0->tsval_recent_age = tcp_time_now ();
2466 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2467 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2469 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2470 << new_tc0->snd_wscale;
2471 new_tc0->snd_wl1 = seq0;
2472 new_tc0->snd_wl2 = ack0;
2474 tcp_connection_init_vars (new_tc0);
2476 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2477 if (PREDICT_TRUE (tcp_ack (tcp0)))
2479 /* Our SYN is ACKed: we have iss < ack = snd_una */
2481 /* TODO Dequeue acknowledged segments if we support Fast Open */
2482 new_tc0->snd_una = ack0;
2483 new_tc0->state = TCP_STATE_ESTABLISHED;
2485 /* Make sure las is initialized for the wnd computation */
2486 new_tc0->rcv_las = new_tc0->rcv_nxt;
2488 /* Notify app that we have connection. If session layer can't
2489 * allocate session send reset */
2490 if (session_stream_connect_notify (&new_tc0->connection, 0))
2492 clib_warning ("connect notify fail");
2493 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2494 tcp_connection_cleanup (new_tc0);
2498 new_tc0->tx_fifo_size =
2499 transport_tx_fifo_size (&new_tc0->connection);
2500 /* Update rtt with the syn-ack sample */
2501 tcp_estimate_initial_rtt (new_tc0);
2502 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2503 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2505 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2508 new_tc0->state = TCP_STATE_SYN_RCVD;
2510 /* Notify app that we have connection */
2511 if (session_stream_connect_notify (&new_tc0->connection, 0))
2513 tcp_connection_cleanup (new_tc0);
2514 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2515 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2519 new_tc0->tx_fifo_size =
2520 transport_tx_fifo_size (&new_tc0->connection);
2521 new_tc0->rtt_ts = 0;
2522 tcp_init_snd_vars (new_tc0);
2523 tcp_send_synack (new_tc0);
2524 error0 = TCP_ERROR_SYNS_RCVD;
2528 /* Read data, if any */
2529 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2531 clib_warning ("rcvd data in syn-sent");
2532 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2533 if (error0 == TCP_ERROR_ACK_OK)
2534 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2538 tcp_program_ack (wrk, new_tc0);
2543 tcp_inc_counter (syn_sent, error0, 1);
2544 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2546 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2547 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2548 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
2552 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2554 tcp_inc_counter (syn_sent, TCP_ERROR_EVENT_FIFO_FULL, errors);
2555 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2557 return from_frame->n_vectors;
2561 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2562 vlib_frame_t * from_frame)
2564 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2568 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2569 vlib_frame_t * from_frame)
2571 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2575 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2577 .function = tcp4_syn_sent,
2578 .name = "tcp4-syn-sent",
2579 /* Takes a vector of packets. */
2580 .vector_size = sizeof (u32),
2581 .n_errors = TCP_N_ERROR,
2582 .error_strings = tcp_error_strings,
2583 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2586 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2587 foreach_tcp_state_next
2590 .format_trace = format_tcp_rx_trace_short,
2594 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2597 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2599 .function = tcp6_syn_sent_rcv,
2600 .name = "tcp6-syn-sent",
2601 /* Takes a vector of packets. */
2602 .vector_size = sizeof (u32),
2603 .n_errors = TCP_N_ERROR,
2604 .error_strings = tcp_error_strings,
2605 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2608 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2609 foreach_tcp_state_next
2612 .format_trace = format_tcp_rx_trace_short,
2616 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2618 vlib_node_registration_t tcp4_rcv_process_node;
2619 vlib_node_registration_t tcp6_rcv_process_node;
2622 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2623 * as per RFC793 p. 64
2626 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2627 vlib_frame_t * from_frame, int is_ip4)
2629 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2630 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2631 u32 n_left_from, *from;
2633 from = first_buffer = vlib_frame_vector_args (from_frame);
2634 n_left_from = from_frame->n_vectors;
2636 while (n_left_from > 0)
2638 u32 bi0, error0 = TCP_ERROR_NONE;
2639 tcp_header_t *tcp0 = 0;
2640 tcp_connection_t *tc0;
2648 b0 = vlib_get_buffer (vm, bi0);
2649 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2651 if (PREDICT_FALSE (tc0 == 0))
2653 error0 = TCP_ERROR_INVALID_CONNECTION;
2657 tcp0 = tcp_buffer_hdr (b0);
2658 is_fin0 = tcp_is_fin (tcp0);
2660 /* SYNs, FINs and data consume sequence numbers */
2661 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2662 + tcp_is_syn (tcp0) + is_fin0 + vnet_buffer (b0)->tcp.data_len;
2666 tcp_connection_t *tmp;
2667 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2669 if (tmp->state != tc0->state)
2671 clib_warning ("state changed");
2677 * Special treatment for CLOSED
2679 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2681 error0 = TCP_ERROR_CONNECTION_CLOSED;
2686 * For all other states (except LISTEN)
2689 /* 1-4: check SEQ, RST, SYN */
2690 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2693 /* 5: check the ACK field */
2696 case TCP_STATE_SYN_RCVD:
2698 * If the segment acknowledgment is not acceptable, form a
2700 * <SEQ=SEG.ACK><CTL=RST>
2703 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2705 TCP_DBG ("connection not accepted");
2706 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2707 error0 = TCP_ERROR_ACK_INVALID;
2711 /* Update rtt and rto */
2712 tcp_estimate_initial_rtt (tc0);
2714 /* Switch state to ESTABLISHED */
2715 tc0->state = TCP_STATE_ESTABLISHED;
2716 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2718 /* Initialize session variables */
2719 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2720 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2721 << tc0->rcv_opts.wscale;
2722 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2723 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2725 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2726 tcp_retransmit_timer_reset (tc0);
2727 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2728 stream_session_accept_notify (&tc0->connection);
2729 error0 = TCP_ERROR_ACK_OK;
2731 case TCP_STATE_ESTABLISHED:
2732 /* We can get packets in established state here because they
2733 * were enqueued before state change */
2734 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2738 case TCP_STATE_FIN_WAIT_1:
2739 /* In addition to the processing for the ESTABLISHED state, if
2740 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2741 * continue processing in that state. */
2742 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2745 /* Still have to send the FIN */
2746 if (tc0->flags & TCP_CONN_FINPNDG)
2748 /* TX fifo finally drained */
2749 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2752 /* If FIN is ACKed */
2753 else if (tc0->snd_una == tc0->snd_una_max)
2755 tc0->state = TCP_STATE_FIN_WAIT_2;
2756 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2758 /* Stop all retransmit timers because we have nothing more
2759 * to send. Enable waitclose though because we're willing to
2760 * wait for peer's FIN but not indefinitely. */
2761 tcp_connection_timers_reset (tc0);
2762 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2764 /* Don't try to deq the FIN acked */
2765 if (tc0->burst_acked > 1)
2766 stream_session_dequeue_drop (&tc0->connection,
2767 tc0->burst_acked - 1);
2768 tc0->burst_acked = 0;
2771 case TCP_STATE_FIN_WAIT_2:
2772 /* In addition to the processing for the ESTABLISHED state, if
2773 * the retransmission queue is empty, the user's CLOSE can be
2774 * acknowledged ("ok") but do not delete the TCB. */
2775 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2777 tc0->burst_acked = 0;
2779 case TCP_STATE_CLOSE_WAIT:
2780 /* Do the same processing as for the ESTABLISHED state. */
2781 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2784 if (tc0->flags & TCP_CONN_FINPNDG)
2786 /* TX fifo finally drained */
2787 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2790 tcp_connection_timers_reset (tc0);
2791 tc0->state = TCP_STATE_LAST_ACK;
2792 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2796 case TCP_STATE_CLOSING:
2797 /* In addition to the processing for the ESTABLISHED state, if
2798 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2799 * otherwise ignore the segment. */
2800 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2803 tc0->state = TCP_STATE_TIME_WAIT;
2804 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2805 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2809 case TCP_STATE_LAST_ACK:
2810 /* The only thing that [should] arrive in this state is an
2811 * acknowledgment of our FIN. If our FIN is now acknowledged,
2812 * delete the TCB, enter the CLOSED state, and return. */
2814 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2816 error0 = TCP_ERROR_ACK_INVALID;
2819 error0 = TCP_ERROR_ACK_OK;
2820 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2821 /* Apparently our ACK for the peer's FIN was lost */
2822 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2828 tc0->state = TCP_STATE_CLOSED;
2829 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2831 /* Don't free the connection from the data path since
2832 * we can't ensure that we have no packets already enqueued
2833 * to output. Rely instead on the waitclose timer */
2834 tcp_connection_timers_reset (tc0);
2835 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, 1);
2840 case TCP_STATE_TIME_WAIT:
2841 /* The only thing that can arrive in this state is a
2842 * retransmission of the remote FIN. Acknowledge it, and restart
2843 * the 2 MSL timeout. */
2845 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2848 tcp_program_ack (wrk, tc0);
2849 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2857 /* 6: check the URG bit TODO */
2859 /* 7: process the segment text */
2862 case TCP_STATE_ESTABLISHED:
2863 case TCP_STATE_FIN_WAIT_1:
2864 case TCP_STATE_FIN_WAIT_2:
2865 if (vnet_buffer (b0)->tcp.data_len)
2866 error0 = tcp_segment_rcv (wrk, tc0, b0);
2870 case TCP_STATE_CLOSE_WAIT:
2871 case TCP_STATE_CLOSING:
2872 case TCP_STATE_LAST_ACK:
2873 case TCP_STATE_TIME_WAIT:
2874 /* This should not occur, since a FIN has been received from the
2875 * remote side. Ignore the segment text. */
2879 /* 8: check the FIN bit */
2885 case TCP_STATE_ESTABLISHED:
2886 case TCP_STATE_SYN_RCVD:
2887 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2888 tcp_connection_timers_reset (tc0);
2890 stream_session_disconnect_notify (&tc0->connection);
2891 tc0->state = TCP_STATE_CLOSE_WAIT;
2892 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2894 case TCP_STATE_CLOSE_WAIT:
2895 case TCP_STATE_CLOSING:
2896 case TCP_STATE_LAST_ACK:
2899 case TCP_STATE_FIN_WAIT_1:
2900 tc0->state = TCP_STATE_CLOSING;
2901 tcp_program_ack (wrk, tc0);
2902 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2903 /* Wait for ACK but not forever */
2904 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2906 case TCP_STATE_FIN_WAIT_2:
2907 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2908 tc0->state = TCP_STATE_TIME_WAIT;
2909 tcp_connection_timers_reset (tc0);
2910 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2911 tcp_program_ack (wrk, tc0);
2912 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2914 case TCP_STATE_TIME_WAIT:
2915 /* Remain in the TIME-WAIT state. Restart the time-wait
2918 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2921 error0 = TCP_ERROR_FIN_RCVD;
2922 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2926 tcp_inc_counter (rcv_process, error0, 1);
2927 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2929 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2930 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2934 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2936 tcp_inc_counter (rcv_process, TCP_ERROR_EVENT_FIFO_FULL, errors);
2937 tcp_handle_postponed_dequeues (wrk);
2938 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2940 return from_frame->n_vectors;
2944 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2945 vlib_frame_t * from_frame)
2947 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2951 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2952 vlib_frame_t * from_frame)
2954 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2958 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2960 .function = tcp4_rcv_process,
2961 .name = "tcp4-rcv-process",
2962 /* Takes a vector of packets. */
2963 .vector_size = sizeof (u32),
2964 .n_errors = TCP_N_ERROR,
2965 .error_strings = tcp_error_strings,
2966 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2969 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2970 foreach_tcp_state_next
2973 .format_trace = format_tcp_rx_trace_short,
2977 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2980 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2982 .function = tcp6_rcv_process,
2983 .name = "tcp6-rcv-process",
2984 /* Takes a vector of packets. */
2985 .vector_size = sizeof (u32),
2986 .n_errors = TCP_N_ERROR,
2987 .error_strings = tcp_error_strings,
2988 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2991 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2992 foreach_tcp_state_next
2995 .format_trace = format_tcp_rx_trace_short,
2999 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
3001 vlib_node_registration_t tcp4_listen_node;
3002 vlib_node_registration_t tcp6_listen_node;
3005 * LISTEN state processing as per RFC 793 p. 65
3008 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3009 vlib_frame_t * from_frame, int is_ip4)
3011 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3012 u32 my_thread_index = vm->thread_index;
3014 from = first_buffer = vlib_frame_vector_args (from_frame);
3015 n_left_from = from_frame->n_vectors;
3017 while (n_left_from > 0)
3022 tcp_header_t *th0 = 0;
3023 tcp_connection_t *lc0;
3026 tcp_connection_t *child0;
3027 u32 error0 = TCP_ERROR_NONE;
3033 b0 = vlib_get_buffer (vm, bi0);
3034 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3038 ip40 = vlib_buffer_get_current (b0);
3039 th0 = ip4_next_header (ip40);
3043 ip60 = vlib_buffer_get_current (b0);
3044 th0 = ip6_next_header (ip60);
3047 /* Create child session. For syn-flood protection use filter */
3049 /* 1. first check for an RST: handled in dispatch */
3050 /* if (tcp_rst (th0))
3054 /* 2. second check for an ACK: handled in dispatch */
3055 /* if (tcp_ack (th0))
3057 tcp_send_reset (b0, is_ip4);
3062 /* 3. check for a SYN (did that already) */
3064 /* Make sure connection wasn't just created */
3065 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3067 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3069 error0 = TCP_ERROR_CREATE_EXISTS;
3073 /* Create child session and send SYN-ACK */
3074 child0 = tcp_connection_new (my_thread_index);
3075 child0->c_lcl_port = th0->dst_port;
3076 child0->c_rmt_port = th0->src_port;
3077 child0->c_is_ip4 = is_ip4;
3078 child0->state = TCP_STATE_SYN_RCVD;
3079 child0->c_fib_index = lc0->c_fib_index;
3083 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3084 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3088 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
3089 sizeof (ip6_address_t));
3090 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
3091 sizeof (ip6_address_t));
3094 if (tcp_options_parse (th0, &child0->rcv_opts))
3096 clib_warning ("options parse fail");
3100 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3101 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3102 child0->rcv_las = child0->rcv_nxt;
3103 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3105 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3106 * segments are used to initialize PAWS. */
3107 if (tcp_opts_tstamp (&child0->rcv_opts))
3109 child0->tsval_recent = child0->rcv_opts.tsval;
3110 child0->tsval_recent_age = tcp_time_now ();
3113 if (tcp_opts_wscale (&child0->rcv_opts))
3114 child0->snd_wscale = child0->rcv_opts.wscale;
3116 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3117 << child0->snd_wscale;
3118 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3119 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3121 tcp_connection_init_vars (child0);
3122 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
3124 if (stream_session_accept (&child0->connection, lc0->c_s_index,
3127 clib_warning ("session accept fail");
3128 tcp_connection_cleanup (child0);
3129 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3133 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3134 tcp_send_synack (child0);
3135 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
3139 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3141 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3142 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3143 clib_memcpy (&t0->tcp_connection, lc0, sizeof (t0->tcp_connection));
3146 n_syns += (error0 == TCP_ERROR_NONE);
3149 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3150 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3152 return from_frame->n_vectors;
3156 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3157 vlib_frame_t * from_frame)
3159 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3163 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3164 vlib_frame_t * from_frame)
3166 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3170 VLIB_REGISTER_NODE (tcp4_listen_node) =
3172 .function = tcp4_listen,
3173 .name = "tcp4-listen",
3174 /* Takes a vector of packets. */
3175 .vector_size = sizeof (u32),
3176 .n_errors = TCP_N_ERROR,
3177 .error_strings = tcp_error_strings,
3178 .n_next_nodes = TCP_LISTEN_N_NEXT,
3181 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3182 foreach_tcp_state_next
3185 .format_trace = format_tcp_rx_trace_short,
3189 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
3192 VLIB_REGISTER_NODE (tcp6_listen_node) =
3194 .function = tcp6_listen,
3195 .name = "tcp6-listen",
3196 /* Takes a vector of packets. */
3197 .vector_size = sizeof (u32),
3198 .n_errors = TCP_N_ERROR,
3199 .error_strings = tcp_error_strings,
3200 .n_next_nodes = TCP_LISTEN_N_NEXT,
3203 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3204 foreach_tcp_state_next
3207 .format_trace = format_tcp_rx_trace_short,
3211 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
3213 vlib_node_registration_t tcp4_input_node;
3214 vlib_node_registration_t tcp6_input_node;
3216 typedef enum _tcp_input_next
3218 TCP_INPUT_NEXT_DROP,
3219 TCP_INPUT_NEXT_LISTEN,
3220 TCP_INPUT_NEXT_RCV_PROCESS,
3221 TCP_INPUT_NEXT_SYN_SENT,
3222 TCP_INPUT_NEXT_ESTABLISHED,
3223 TCP_INPUT_NEXT_RESET,
3224 TCP_INPUT_NEXT_PUNT,
3228 #define foreach_tcp4_input_next \
3229 _ (DROP, "ip4-drop") \
3230 _ (LISTEN, "tcp4-listen") \
3231 _ (RCV_PROCESS, "tcp4-rcv-process") \
3232 _ (SYN_SENT, "tcp4-syn-sent") \
3233 _ (ESTABLISHED, "tcp4-established") \
3234 _ (RESET, "tcp4-reset") \
3235 _ (PUNT, "ip4-punt")
3237 #define foreach_tcp6_input_next \
3238 _ (DROP, "ip6-drop") \
3239 _ (LISTEN, "tcp6-listen") \
3240 _ (RCV_PROCESS, "tcp6-rcv-process") \
3241 _ (SYN_SENT, "tcp6-syn-sent") \
3242 _ (ESTABLISHED, "tcp6-established") \
3243 _ (RESET, "tcp6-reset") \
3244 _ (PUNT, "ip6-punt")
3246 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3249 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3250 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3252 tcp_connection_t *tc;
3257 for (i = 0; i < n_bufs; i++)
3259 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3261 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3262 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3264 tcp = vlib_buffer_get_current (bs[i]);
3265 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3271 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3273 if (*error == TCP_ERROR_FILTERED)
3275 *next = TCP_INPUT_NEXT_DROP;
3277 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3279 *next = TCP_INPUT_NEXT_PUNT;
3280 *error = TCP_ERROR_PUNT;
3284 *next = TCP_INPUT_NEXT_RESET;
3285 *error = TCP_ERROR_NO_LISTENER;
3289 static inline tcp_connection_t *
3290 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3293 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3294 int n_advance_bytes, n_data_bytes;
3295 transport_connection_t *tc;
3301 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3302 tcp = ip4_next_header (ip4);
3303 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3304 n_advance_bytes = (ip4_header_bytes (ip4) + tcp_header_bytes (tcp));
3305 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3307 /* Length check. Checksum computed by ipx_local no need to compute again */
3308 if (PREDICT_FALSE (n_advance_bytes < 0))
3310 *error = TCP_ERROR_LENGTH;
3314 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3315 &ip4->src_address, tcp->dst_port,
3316 tcp->src_port, TRANSPORT_PROTO_TCP,
3317 thread_index, &is_filtered);
3321 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3322 tcp = ip6_next_header (ip6);
3323 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3324 n_advance_bytes = tcp_header_bytes (tcp);
3325 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3327 n_advance_bytes += sizeof (ip6[0]);
3329 if (PREDICT_FALSE (n_advance_bytes < 0))
3331 *error = TCP_ERROR_LENGTH;
3335 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3336 &ip6->src_address, tcp->dst_port,
3337 tcp->src_port, TRANSPORT_PROTO_TCP,
3338 thread_index, &is_filtered);
3341 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3342 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3343 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3344 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3345 vnet_buffer (b)->tcp.flags = 0;
3347 *error = is_filtered ? TCP_ERROR_FILTERED : *error;
3349 return tcp_get_connection_from_transport (tc);
3353 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3354 vlib_buffer_t * b, u16 * next, u32 * error)
3359 tcp = tcp_buffer_hdr (b);
3360 flags = tcp->flags & filter_flags;
3361 *next = tm->dispatch_table[tc->state][flags].next;
3362 *error = tm->dispatch_table[tc->state][flags].error;
3364 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3365 || *next == TCP_INPUT_NEXT_RESET))
3367 /* Overload tcp flags to store state */
3368 tcp_state_t state = tc->state;
3369 vnet_buffer (b)->tcp.flags = tc->state;
3371 if (*error == TCP_ERROR_DISPATCH)
3372 clib_warning ("disp error state %U flags %U", format_tcp_state,
3373 state, format_tcp_flags, (int) flags);
3378 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3379 vlib_frame_t * frame, int is_ip4)
3381 u32 n_left_from, *from, thread_index = vm->thread_index;
3382 tcp_main_t *tm = vnet_get_tcp_main ();
3383 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3384 u16 nexts[VLIB_FRAME_SIZE], *next;
3386 tcp_set_time_now (tcp_get_worker (thread_index));
3388 from = vlib_frame_vector_args (frame);
3389 n_left_from = frame->n_vectors;
3390 vlib_get_buffers (vm, from, bufs, n_left_from);
3395 while (n_left_from >= 4)
3397 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3398 tcp_connection_t *tc0, *tc1;
3401 vlib_prefetch_buffer_header (b[2], STORE);
3402 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3404 vlib_prefetch_buffer_header (b[3], STORE);
3405 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3408 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3410 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3411 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4);
3413 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3415 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3416 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3418 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3419 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3421 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3422 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
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);
3435 if (PREDICT_TRUE (tc1 != 0))
3437 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3438 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3439 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3442 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3449 while (n_left_from > 0)
3451 tcp_connection_t *tc0;
3452 u32 error0 = TCP_ERROR_NO_LISTENER;
3454 if (n_left_from > 1)
3456 vlib_prefetch_buffer_header (b[1], STORE);
3457 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3460 next[0] = TCP_INPUT_NEXT_DROP;
3461 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3462 if (PREDICT_TRUE (tc0 != 0))
3464 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3465 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3466 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3469 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3476 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3477 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3479 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3480 return frame->n_vectors;
3484 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3485 vlib_frame_t * from_frame)
3487 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3491 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3492 vlib_frame_t * from_frame)
3494 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3498 VLIB_REGISTER_NODE (tcp4_input_node) =
3500 .function = tcp4_input,
3501 .name = "tcp4-input",
3502 /* Takes a vector of packets. */
3503 .vector_size = sizeof (u32),
3504 .n_errors = TCP_N_ERROR,
3505 .error_strings = tcp_error_strings,
3506 .n_next_nodes = TCP_INPUT_N_NEXT,
3509 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3510 foreach_tcp4_input_next
3513 .format_buffer = format_tcp_header,
3514 .format_trace = format_tcp_rx_trace,
3518 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3521 VLIB_REGISTER_NODE (tcp6_input_node) =
3523 .function = tcp6_input,
3524 .name = "tcp6-input",
3525 /* Takes a vector of packets. */
3526 .vector_size = sizeof (u32),
3527 .n_errors = TCP_N_ERROR,
3528 .error_strings = tcp_error_strings,
3529 .n_next_nodes = TCP_INPUT_N_NEXT,
3532 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3533 foreach_tcp6_input_next
3536 .format_buffer = format_tcp_header,
3537 .format_trace = format_tcp_rx_trace,
3541 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3544 tcp_dispatch_table_init (tcp_main_t * tm)
3547 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3548 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3550 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3551 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3554 #define _(t,f,n,e) \
3556 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3557 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3560 /* SYNs for new connections -> tcp-listen. */
3561 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3562 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3563 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_RST_RCVD);
3564 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3566 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3567 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3568 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3569 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3571 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3572 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3574 /* SYN-ACK for a SYN */
3575 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3577 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3578 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3579 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3581 /* ACK for for established connection -> tcp-established. */
3582 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3583 /* FIN for for established connection -> tcp-established. */
3584 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3585 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3587 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3588 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3590 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3591 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3593 /* ACK or FIN-ACK to our FIN */
3594 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3595 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3597 /* FIN in reply to our FIN from the other side */
3598 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3599 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3600 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3601 /* FIN confirming that the peer (app) has closed */
3602 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3603 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3604 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3606 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3607 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3609 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3610 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3611 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3613 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3614 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3615 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3616 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3618 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3619 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3620 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3621 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3622 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3623 TCP_ERROR_CONNECTION_CLOSED);
3627 static clib_error_t *
3628 tcp_input_init (vlib_main_t * vm)
3630 clib_error_t *error = 0;
3631 tcp_main_t *tm = vnet_get_tcp_main ();
3633 if ((error = vlib_call_init_function (vm, tcp_init)))
3636 /* Initialize dispatch table. */
3637 tcp_dispatch_table_init (tm);
3642 VLIB_INIT_FUNCTION (tcp_input_init);
3645 * fd.io coding-style-patch-verification: ON
3648 * eval: (c-set-style "gnu")