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 * @param is_syn set if packet is syn
125 * @return -1 if parsing failed
128 tcp_options_parse (tcp_header_t * th, tcp_options_t * to, u8 is_syn)
131 u8 opt_len, opts_len, kind;
135 opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t);
136 data = (const u8 *) (th + 1);
138 /* Zero out all flags but those set in SYN */
139 to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE
140 | TCP_OPTS_FLAG_TSTAMP | TCP_OPTION_MSS);
142 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
146 /* Get options length */
147 if (kind == TCP_OPTION_EOL)
149 else if (kind == TCP_OPTION_NOOP)
161 /* weird option length */
162 if (opt_len < 2 || opt_len > opts_len)
172 if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
174 to->flags |= TCP_OPTS_FLAG_MSS;
175 to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
178 case TCP_OPTION_WINDOW_SCALE:
181 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
183 to->flags |= TCP_OPTS_FLAG_WSCALE;
184 to->wscale = data[2];
185 if (to->wscale > TCP_MAX_WND_SCALE)
187 clib_warning ("Illegal window scaling value: %d",
189 to->wscale = TCP_MAX_WND_SCALE;
193 case TCP_OPTION_TIMESTAMP:
195 to->flags |= TCP_OPTS_FLAG_TSTAMP;
196 if ((to->flags & TCP_OPTS_FLAG_TSTAMP)
197 && opt_len == TCP_OPTION_LEN_TIMESTAMP)
199 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
200 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
203 case TCP_OPTION_SACK_PERMITTED:
206 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
207 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
209 case TCP_OPTION_SACK_BLOCK:
210 /* If SACK permitted was not advertised or a SYN, break */
211 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
214 /* If too short or not correctly formatted, break */
215 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
218 to->flags |= TCP_OPTS_FLAG_SACK;
219 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
220 vec_reset_length (to->sacks);
221 for (j = 0; j < to->n_sack_blocks; j++)
223 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 8 * j));
224 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 8 * j));
225 vec_add1 (to->sacks, b);
229 /* Nothing to see here */
237 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
238 * timestamp to echo and it's less than tsval_recent, drop segment
239 * but still send an ACK in order to retain TCP's mechanism for detecting
240 * and recovering from half-open connections
242 * Or at least that's what the theory says. It seems that this might not work
243 * very well with packet reordering and fast retransmit. XXX
246 tcp_segment_check_paws (tcp_connection_t * tc)
248 return tcp_opts_tstamp (&tc->rcv_opts)
249 && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent);
253 * Update tsval recent
256 tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
259 * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
260 * of an incoming segment:
261 * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
262 * then the TSval from the segment is copied to TS.Recent;
263 * otherwise, the TSval is ignored.
265 if (tcp_opts_tstamp (&tc->rcv_opts) && seq_leq (seq, tc->rcv_las)
266 && seq_leq (tc->rcv_las, seq_end))
268 ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval));
269 tc->tsval_recent = tc->rcv_opts.tsval;
270 tc->tsval_recent_age = tcp_time_now_w_thread (tc->c_thread_index);
275 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
277 * It first verifies if segment has a wrapped sequence number (PAWS) and then
278 * does the processing associated to the first four steps (ignoring security
279 * and precedence): sequence number, rst bit and syn bit checks.
281 * @return 0 if segments passes validation.
284 tcp_segment_validate (tcp_worker_ctx_t * wrk, tcp_connection_t * tc0,
285 vlib_buffer_t * b0, tcp_header_t * th0, u32 * error0)
287 /* We could get a burst of RSTs interleaved with acks */
288 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
290 tcp_send_reset (tc0);
291 *error0 = TCP_ERROR_CONNECTION_CLOSED;
295 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
297 *error0 = TCP_ERROR_SEGMENT_INVALID;
301 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts, 0)))
303 *error0 = TCP_ERROR_OPTIONS;
307 if (PREDICT_FALSE (tcp_segment_check_paws (tc0)))
309 *error0 = TCP_ERROR_PAWS;
310 TCP_EVT_DBG (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
311 vnet_buffer (b0)->tcp.seq_end);
313 /* If it just so happens that a segment updates tsval_recent for a
314 * segment over 24 days old, invalidate tsval_recent. */
315 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
316 tcp_time_now_w_thread (tc0->c_thread_index)))
318 tc0->tsval_recent = tc0->rcv_opts.tsval;
319 clib_warning ("paws failed - really old segment. REALLY?");
323 /* Drop after ack if not rst */
326 tcp_program_ack (wrk, tc0);
327 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
333 /* 1st: check sequence number */
334 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
335 vnet_buffer (b0)->tcp.seq_end))
337 *error0 = TCP_ERROR_RCV_WND;
338 /* If our window is 0 and the packet is in sequence, let it pass
339 * through for ack processing. It should be dropped later. */
340 if (!(tc0->rcv_wnd == 0
341 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number))
343 /* If not RST, send dup ack */
346 tcp_program_dupack (wrk, tc0);
347 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
353 /* 2nd: check the RST bit */
354 if (PREDICT_FALSE (tcp_rst (th0)))
356 tcp_connection_reset (tc0);
357 *error0 = TCP_ERROR_RST_RCVD;
361 /* 3rd: check security and precedence (skip) */
363 /* 4th: check the SYN bit */
364 if (PREDICT_FALSE (tcp_syn (th0)))
366 /* TODO implement RFC 5961 */
367 if (tc0->state == TCP_STATE_SYN_RCVD)
369 tcp_options_parse (th0, &tc0->rcv_opts, 1);
370 tcp_send_synack (tc0);
371 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0, 0);
375 tcp_program_ack (wrk, tc0);
376 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, tc0);
381 /* If segment in window, save timestamp */
382 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
383 vnet_buffer (b0)->tcp.seq_end);
391 tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0)
393 /* SND.UNA =< SEG.ACK =< SND.NXT */
394 return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number)
395 && seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt));
399 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
401 * Note that although the original article, srtt and rttvar are scaled
402 * to minimize round-off errors, here we don't. Instead, we rely on
403 * better precision time measurements.
405 * TODO support us rtt resolution
408 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
414 err = mrtt - tc->srtt;
416 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
417 * The increase should be bound */
418 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
419 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
420 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
424 /* First measurement. */
426 tc->rttvar = mrtt >> 1;
431 tcp_update_rto (tcp_connection_t * tc)
433 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
434 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
438 * Update RTT estimate and RTO timer
440 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
441 * timing. Middle boxes are known to fiddle with TCP options so we
442 * should give higher priority to ACK timing.
444 * This should be called only if previously sent bytes have been acked.
446 * return 1 if valid rtt 0 otherwise
449 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
453 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
454 * RTT because they're ambiguous. */
455 if (tcp_in_cong_recovery (tc) || tc->sack_sb.sacked_bytes)
457 if (tcp_in_recovery (tc))
462 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
464 f64 sample = tcp_time_now_us (tc->c_thread_index) - tc->rtt_ts;
465 tc->mrtt_us = tc->mrtt_us + (sample - tc->mrtt_us) * 0.125;
466 mrtt = clib_max ((u32) (sample * THZ), 1);
467 /* Allow measuring of a new RTT */
470 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
471 * snd_una, i.e., the left side of the send window:
472 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
473 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
475 u32 now = tcp_time_now_w_thread (tc->c_thread_index);
476 mrtt = clib_max (now - tc->rcv_opts.tsecr, 1);
479 /* Ignore dubious measurements */
480 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
483 tcp_estimate_rtt (tc, mrtt);
487 /* If we got here something must've been ACKed so make sure boff is 0,
488 * even if mrtt is not valid since we update the rto lower */
496 tcp_estimate_initial_rtt (tcp_connection_t * tc)
498 u8 thread_index = vlib_num_workers ()? 1 : 0;
503 tc->mrtt_us = tcp_time_now_us (thread_index) - tc->rtt_ts;
504 mrtt = clib_max ((u32) (tc->mrtt_us * THZ), 1);
509 mrtt = tcp_time_now_w_thread (thread_index) - tc->rcv_opts.tsecr;
510 mrtt = clib_max (mrtt, 1);
511 tc->mrtt_us = (f64) mrtt *TCP_TICK;
514 if (mrtt > 0 && mrtt < TCP_RTT_MAX)
515 tcp_estimate_rtt (tc, mrtt);
519 * Dequeue bytes for connections that have received acks in last burst
522 tcp_handle_postponed_dequeues (tcp_worker_ctx_t * wrk)
524 u32 thread_index = wrk->vm->thread_index;
525 u32 *pending_deq_acked;
526 tcp_connection_t *tc;
529 if (!vec_len (wrk->pending_deq_acked))
532 pending_deq_acked = wrk->pending_deq_acked;
533 for (i = 0; i < vec_len (pending_deq_acked); i++)
535 tc = tcp_connection_get (pending_deq_acked[i], thread_index);
536 tc->flags &= ~TCP_CONN_DEQ_PENDING;
538 if (PREDICT_FALSE (!tc->burst_acked))
541 /* Dequeue the newly ACKed bytes */
542 stream_session_dequeue_drop (&tc->connection, tc->burst_acked);
544 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
546 /* If everything has been acked, stop retransmit timer
547 * otherwise update. */
548 tcp_retransmit_timer_update (tc);
550 /* If not congested, update pacer based on our new
552 if (!tcp_in_fastrecovery (tc))
553 tcp_connection_tx_pacer_update (tc);
555 _vec_len (wrk->pending_deq_acked) = 0;
559 tcp_program_dequeue (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
561 if (!(tc->flags & TCP_CONN_DEQ_PENDING))
563 vec_add1 (wrk->pending_deq_acked, tc->c_c_index);
564 tc->flags |= TCP_CONN_DEQ_PENDING;
566 tc->burst_acked += tc->bytes_acked + tc->sack_sb.snd_una_adv;
570 * Check if duplicate ack as per RFC5681 Sec. 2
573 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
576 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
577 && seq_gt (tc->snd_una_max, tc->snd_una)
578 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
579 && (prev_snd_wnd == tc->snd_wnd));
583 * Checks if ack is a congestion control event.
586 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
587 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
589 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
590 * defined to be 'duplicate' */
591 *is_dack = tc->sack_sb.last_sacked_bytes
592 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
594 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
598 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
600 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
601 return hole - sb->holes;
605 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
607 return hole->end - hole->start;
610 sack_scoreboard_hole_t *
611 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
613 if (index != TCP_INVALID_SACK_HOLE_INDEX)
614 return pool_elt_at_index (sb->holes, index);
618 sack_scoreboard_hole_t *
619 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
621 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
622 return pool_elt_at_index (sb->holes, hole->next);
626 sack_scoreboard_hole_t *
627 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
629 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
630 return pool_elt_at_index (sb->holes, hole->prev);
634 sack_scoreboard_hole_t *
635 scoreboard_first_hole (sack_scoreboard_t * sb)
637 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
638 return pool_elt_at_index (sb->holes, sb->head);
642 sack_scoreboard_hole_t *
643 scoreboard_last_hole (sack_scoreboard_t * sb)
645 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
646 return pool_elt_at_index (sb->holes, sb->tail);
651 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
653 sack_scoreboard_hole_t *next, *prev;
655 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
657 next = pool_elt_at_index (sb->holes, hole->next);
658 next->prev = hole->prev;
662 sb->tail = hole->prev;
665 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
667 prev = pool_elt_at_index (sb->holes, hole->prev);
668 prev->next = hole->next;
672 sb->head = hole->next;
675 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
676 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
678 /* Poison the entry */
680 clib_memset (hole, 0xfe, sizeof (*hole));
682 pool_put (sb->holes, hole);
685 static sack_scoreboard_hole_t *
686 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
689 sack_scoreboard_hole_t *hole, *next, *prev;
692 pool_get (sb->holes, hole);
693 clib_memset (hole, 0, sizeof (*hole));
697 hole_index = scoreboard_hole_index (sb, hole);
699 prev = scoreboard_get_hole (sb, prev_index);
702 hole->prev = prev_index;
703 hole->next = prev->next;
705 if ((next = scoreboard_next_hole (sb, hole)))
706 next->prev = hole_index;
708 sb->tail = hole_index;
710 prev->next = hole_index;
714 sb->head = hole_index;
715 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
716 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
723 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
725 sack_scoreboard_hole_t *left, *right;
726 u32 bytes = 0, blks = 0;
729 sb->sacked_bytes = 0;
730 left = scoreboard_last_hole (sb);
734 if (seq_gt (sb->high_sacked, left->end))
736 bytes = sb->high_sacked - left->end;
740 while ((right = left)
741 && bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
742 && blks < TCP_DUPACK_THRESHOLD
743 /* left not updated if above conditions fail */
744 && (left = scoreboard_prev_hole (sb, right)))
746 bytes += right->start - left->end;
750 /* left is first lost */
755 sb->lost_bytes += scoreboard_hole_bytes (right);
757 left = scoreboard_prev_hole (sb, right);
759 bytes += right->start - left->end;
761 while ((right = left));
764 sb->sacked_bytes = bytes;
768 * Figure out the next hole to retransmit
770 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
772 sack_scoreboard_hole_t *
773 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
774 sack_scoreboard_hole_t * start,
775 u8 have_unsent, u8 * can_rescue, u8 * snd_limited)
777 sack_scoreboard_hole_t *hole = 0;
779 hole = start ? start : scoreboard_first_hole (sb);
780 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
781 hole = scoreboard_next_hole (sb, hole);
783 /* Nothing, return */
786 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
790 /* Rule (1): if higher than rxt, less than high_sacked and lost */
791 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
793 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
797 /* Rule (2): available unsent data */
800 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
803 /* Rule (3): if hole not lost */
804 else if (seq_lt (hole->start, sb->high_sacked))
807 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
809 /* Rule (4): if hole beyond high_sacked */
812 ASSERT (seq_geq (hole->start, sb->high_sacked));
815 /* HighRxt MUST NOT be updated */
820 if (hole && seq_lt (sb->high_rxt, hole->start))
821 sb->high_rxt = hole->start;
827 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 snd_una)
829 sack_scoreboard_hole_t *hole;
830 hole = scoreboard_first_hole (sb);
833 snd_una = seq_gt (snd_una, hole->start) ? snd_una : hole->start;
834 sb->cur_rxt_hole = sb->head;
836 sb->high_rxt = snd_una;
837 sb->rescue_rxt = snd_una - 1;
841 scoreboard_init (sack_scoreboard_t * sb)
843 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
844 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
845 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
849 scoreboard_clear (sack_scoreboard_t * sb)
851 sack_scoreboard_hole_t *hole;
852 while ((hole = scoreboard_first_hole (sb)))
854 scoreboard_remove_hole (sb, hole);
856 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
857 ASSERT (pool_elts (sb->holes) == 0);
858 sb->sacked_bytes = 0;
859 sb->last_sacked_bytes = 0;
860 sb->last_bytes_delivered = 0;
865 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
869 * Test that scoreboard is sane after recovery
871 * Returns 1 if scoreboard is empty or if first hole beyond
875 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
877 sack_scoreboard_hole_t *hole;
878 hole = scoreboard_first_hole (&tc->sack_sb);
879 return (!hole || (seq_geq (hole->start, tc->snd_una)
880 && seq_lt (hole->end, tc->snd_una_max)));
884 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
886 sack_scoreboard_t *sb = &tc->sack_sb;
887 sack_block_t *blk, tmp;
888 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
889 u32 blk_index = 0, old_sacked_bytes, hole_index;
892 sb->last_sacked_bytes = 0;
893 sb->last_bytes_delivered = 0;
896 if (!tcp_opts_sack (&tc->rcv_opts)
897 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
900 old_sacked_bytes = sb->sacked_bytes;
902 /* Remove invalid blocks */
903 blk = tc->rcv_opts.sacks;
904 while (blk < vec_end (tc->rcv_opts.sacks))
906 if (seq_lt (blk->start, blk->end)
907 && seq_gt (blk->start, tc->snd_una)
908 && seq_gt (blk->start, ack)
909 && seq_lt (blk->start, tc->snd_una_max)
910 && seq_leq (blk->end, tc->snd_una_max))
915 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
918 /* Add block for cumulative ack */
919 if (seq_gt (ack, tc->snd_una))
921 tmp.start = tc->snd_una;
923 vec_add1 (tc->rcv_opts.sacks, tmp);
926 if (vec_len (tc->rcv_opts.sacks) == 0)
929 tcp_scoreboard_trace_add (tc, ack);
931 /* Make sure blocks are ordered */
932 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
933 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
934 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
936 tmp = tc->rcv_opts.sacks[i];
937 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
938 tc->rcv_opts.sacks[j] = tmp;
941 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
943 /* If no holes, insert the first that covers all outstanding bytes */
944 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
945 tc->snd_una, tc->snd_una_max);
946 sb->tail = scoreboard_hole_index (sb, last_hole);
947 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
948 sb->high_sacked = tmp.end;
952 /* If we have holes but snd_una_max is beyond the last hole, update
954 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
955 last_hole = scoreboard_last_hole (sb);
956 if (seq_gt (tc->snd_una_max, last_hole->end))
958 if (seq_geq (last_hole->start, sb->high_sacked))
960 last_hole->end = tc->snd_una_max;
962 /* New hole after high sacked block */
963 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
965 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
969 /* Keep track of max byte sacked for when the last hole
971 if (seq_gt (tmp.end, sb->high_sacked))
972 sb->high_sacked = tmp.end;
975 /* Walk the holes with the SACK blocks */
976 hole = pool_elt_at_index (sb->holes, sb->head);
977 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
979 blk = &tc->rcv_opts.sacks[blk_index];
980 if (seq_leq (blk->start, hole->start))
982 /* Block covers hole. Remove hole */
983 if (seq_geq (blk->end, hole->end))
985 next_hole = scoreboard_next_hole (sb, hole);
987 /* Byte accounting: snd_una needs to be advanced */
992 if (seq_lt (ack, next_hole->start))
993 sb->snd_una_adv = next_hole->start - ack;
994 sb->last_bytes_delivered +=
995 next_hole->start - hole->end;
999 ASSERT (seq_geq (sb->high_sacked, ack));
1000 sb->snd_una_adv = sb->high_sacked - ack;
1001 sb->last_bytes_delivered += sb->high_sacked - hole->end;
1005 scoreboard_remove_hole (sb, hole);
1008 /* Partial 'head' overlap */
1011 if (seq_gt (blk->end, hole->start))
1013 hole->start = blk->end;
1020 /* Hole must be split */
1021 if (seq_lt (blk->end, hole->end))
1023 hole_index = scoreboard_hole_index (sb, hole);
1024 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
1027 /* Pool might've moved */
1028 hole = scoreboard_get_hole (sb, hole_index);
1029 hole->end = blk->start;
1031 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
1033 else if (seq_lt (blk->start, hole->end))
1035 hole->end = blk->start;
1037 hole = scoreboard_next_hole (sb, hole);
1041 if (pool_elts (sb->holes) == 1)
1043 hole = scoreboard_first_hole (sb);
1044 if (hole->start == ack + sb->snd_una_adv
1045 && hole->end == tc->snd_una_max)
1046 scoreboard_remove_hole (sb, hole);
1049 scoreboard_update_bytes (tc, sb);
1050 sb->last_sacked_bytes = sb->sacked_bytes
1051 - (old_sacked_bytes - sb->last_bytes_delivered);
1052 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
1053 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
1054 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
1055 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
1056 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1057 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1058 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
1059 TCP_EVT_DBG (TCP_EVT_CC_SCOREBOARD, tc);
1063 * Try to update snd_wnd based on feedback received from peer.
1065 * If successful, and new window is 'effectively' 0, activate persist
1069 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1071 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1072 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1073 if (seq_lt (tc->snd_wl1, seq)
1074 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1076 tc->snd_wnd = snd_wnd;
1079 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
1081 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
1083 /* Set persist timer if not set and we just got 0 wnd */
1084 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1085 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1086 tcp_persist_timer_set (tc);
1090 tcp_persist_timer_reset (tc);
1091 if (PREDICT_FALSE (!tcp_in_recovery (tc) && tc->rto_boff > 0))
1094 tcp_update_rto (tc);
1101 * Init loss recovery/fast recovery.
1103 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1104 * updated in @ref tcp_cc_handle_event after fast retransmit
1107 tcp_cc_init_congestion (tcp_connection_t * tc)
1109 tcp_fastrecovery_on (tc);
1110 tc->snd_congestion = tc->snd_una_max;
1111 tc->cwnd_acc_bytes = 0;
1112 tc->snd_rxt_bytes = 0;
1113 tc->prev_ssthresh = tc->ssthresh;
1114 tc->prev_cwnd = tc->cwnd;
1115 tc->cc_algo->congestion (tc);
1116 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
1120 tcp_cc_recovery_exit (tcp_connection_t * tc)
1123 tcp_update_rto (tc);
1125 tc->snd_nxt = tc->snd_una_max;
1127 tcp_recovery_off (tc);
1128 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1132 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
1134 tc->cc_algo->recovered (tc);
1135 tc->snd_rxt_bytes = 0;
1136 tc->rcv_dupacks = 0;
1137 tc->snd_nxt = tc->snd_una_max;
1138 tc->snd_rxt_bytes = 0;
1141 tcp_fastrecovery_off (tc);
1142 tcp_fastrecovery_first_off (tc);
1144 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1148 tcp_cc_congestion_undo (tcp_connection_t * tc)
1150 tc->cwnd = tc->prev_cwnd;
1151 tc->ssthresh = tc->prev_ssthresh;
1152 tc->snd_nxt = tc->snd_una_max;
1153 tc->rcv_dupacks = 0;
1154 if (tcp_in_recovery (tc))
1155 tcp_cc_recovery_exit (tc);
1156 else if (tcp_in_fastrecovery (tc))
1157 tcp_cc_fastrecovery_exit (tc);
1158 ASSERT (tc->rto_boff == 0);
1159 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
1163 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1165 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1167 && tcp_opts_tstamp (&tc->rcv_opts)
1168 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1172 tcp_cc_is_spurious_fast_rxt (tcp_connection_t * tc)
1174 return (tcp_in_fastrecovery (tc)
1175 && tc->cwnd > tc->ssthresh + 3 * tc->snd_mss);
1179 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1181 return (tcp_cc_is_spurious_timeout_rxt (tc)
1182 || tcp_cc_is_spurious_fast_rxt (tc));
1186 tcp_cc_recover (tcp_connection_t * tc)
1188 ASSERT (tcp_in_cong_recovery (tc));
1189 if (tcp_cc_is_spurious_retransmit (tc))
1191 tcp_cc_congestion_undo (tc);
1195 if (tcp_in_recovery (tc))
1196 tcp_cc_recovery_exit (tc);
1197 else if (tcp_in_fastrecovery (tc))
1198 tcp_cc_fastrecovery_exit (tc);
1200 ASSERT (tc->rto_boff == 0);
1201 ASSERT (!tcp_in_cong_recovery (tc));
1202 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1207 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
1209 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1211 /* Congestion avoidance */
1212 tcp_cc_rcv_ack (tc);
1214 /* If a cumulative ack, make sure dupacks is 0 */
1215 tc->rcv_dupacks = 0;
1217 /* When dupacks hits the threshold we only enter fast retransmit if
1218 * cumulative ack covers more than snd_congestion. Should snd_una
1219 * wrap this test may fail under otherwise valid circumstances.
1220 * Therefore, proactively update snd_congestion when wrap detected. */
1222 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1223 && seq_gt (tc->snd_congestion, tc->snd_una)))
1224 tc->snd_congestion = tc->snd_una - 1;
1228 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1230 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1234 tcp_should_fastrecover (tcp_connection_t * tc)
1236 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1237 || tcp_should_fastrecover_sack (tc));
1241 tcp_program_fastretransmit (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1243 if (!(tc->flags & TCP_CONN_FRXT_PENDING))
1245 vec_add1 (wrk->pending_fast_rxt, tc->c_c_index);
1246 tc->flags |= TCP_CONN_FRXT_PENDING;
1251 tcp_do_fastretransmits (tcp_worker_ctx_t * wrk)
1253 u32 *ongoing_fast_rxt, burst_bytes, sent_bytes, thread_index;
1254 u32 max_burst_size, burst_size, n_segs = 0, n_segs_now;
1255 tcp_connection_t *tc;
1259 if (vec_len (wrk->pending_fast_rxt) == 0
1260 && vec_len (wrk->postponed_fast_rxt) == 0)
1263 thread_index = wrk->vm->thread_index;
1264 last_cpu_time = wrk->vm->clib_time.last_cpu_time;
1265 ongoing_fast_rxt = wrk->ongoing_fast_rxt;
1266 vec_append (ongoing_fast_rxt, wrk->postponed_fast_rxt);
1267 vec_append (ongoing_fast_rxt, wrk->pending_fast_rxt);
1269 _vec_len (wrk->postponed_fast_rxt) = 0;
1270 _vec_len (wrk->pending_fast_rxt) = 0;
1272 max_burst_size = VLIB_FRAME_SIZE / vec_len (ongoing_fast_rxt);
1273 max_burst_size = clib_max (max_burst_size, 1);
1275 for (i = 0; i < vec_len (ongoing_fast_rxt); i++)
1277 if (n_segs >= VLIB_FRAME_SIZE)
1279 vec_add1 (wrk->postponed_fast_rxt, ongoing_fast_rxt[i]);
1283 tc = tcp_connection_get (ongoing_fast_rxt[i], thread_index);
1284 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1286 if (!tcp_in_fastrecovery (tc))
1289 burst_size = clib_min (max_burst_size, VLIB_FRAME_SIZE - n_segs);
1290 burst_bytes = transport_connection_tx_pacer_burst (&tc->connection,
1292 burst_size = clib_min (burst_size, burst_bytes / tc->snd_mss);
1295 tcp_program_fastretransmit (wrk, tc);
1299 n_segs_now = tcp_fast_retransmit (wrk, tc, burst_size);
1300 sent_bytes = clib_min (n_segs_now * tc->snd_mss, burst_bytes);
1301 transport_connection_tx_pacer_update_bytes (&tc->connection,
1303 n_segs += n_segs_now;
1305 _vec_len (ongoing_fast_rxt) = 0;
1306 wrk->ongoing_fast_rxt = ongoing_fast_rxt;
1310 * One function to rule them all ... and in the darkness bind them
1313 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1317 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1319 if (tc->bytes_acked)
1321 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1325 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1326 * it account for the bytes that left the network.
1328 else if (is_dack && !tcp_in_recovery (tc))
1330 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1331 ASSERT (tc->snd_una != tc->snd_una_max
1332 || tc->sack_sb.last_sacked_bytes);
1336 /* Pure duplicate ack. If some data got acked, it's handled lower */
1337 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1339 ASSERT (tcp_in_fastrecovery (tc));
1340 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1343 else if (tcp_should_fastrecover (tc))
1347 ASSERT (!tcp_in_fastrecovery (tc));
1349 /* Heuristic to catch potential late dupacks
1350 * after fast retransmit exits */
1351 if (is_dack && tc->snd_una == tc->snd_congestion
1352 && timestamp_leq (tc->rcv_opts.tsecr, tc->tsecr_last_ack))
1354 tc->rcv_dupacks = 0;
1358 tcp_cc_init_congestion (tc);
1359 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1361 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1363 tc->cwnd = tc->ssthresh;
1364 scoreboard_init_high_rxt (&tc->sack_sb, tc->snd_una);
1368 /* Post retransmit update cwnd to ssthresh and account for the
1369 * three segments that have left the network and should've been
1370 * buffered at the receiver XXX */
1371 tc->cwnd = tc->ssthresh + 3 * tc->snd_mss;
1374 /* Constrain rate until we get a partial ack */
1375 pacer_wnd = clib_max (0.1 * tc->cwnd, 2 * tc->snd_mss);
1376 tcp_connection_tx_pacer_reset (tc, pacer_wnd,
1377 0 /* start bucket */ );
1378 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index),
1382 else if (!tc->bytes_acked
1383 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1385 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1391 /* Don't allow entry in fast recovery if still in recovery, for now */
1392 else if (0 && is_dack && tcp_in_recovery (tc))
1394 /* If of of the two conditions lower hold, reset dupacks because
1395 * we're probably after timeout (RFC6582 heuristics).
1396 * If Cumulative ack does not cover more than congestion threshold,
1398 * 1) The following doesn't hold: The congestion window is greater
1399 * than SMSS bytes and the difference between highest_ack
1400 * and prev_highest_ack is at most 4*SMSS bytes
1401 * 2) Echoed timestamp in the last non-dup ack does not equal the
1404 if (seq_leq (tc->snd_una, tc->snd_congestion)
1405 && ((!(tc->cwnd > tc->snd_mss
1406 && tc->bytes_acked <= 4 * tc->snd_mss))
1407 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1409 tc->rcv_dupacks = 0;
1414 if (!tc->bytes_acked)
1418 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1421 * Legitimate ACK. 1) See if we can exit recovery
1424 /* Update the pacing rate. For the first partial ack we move from
1425 * the artificially constrained rate to the one after congestion */
1426 tcp_connection_tx_pacer_update (tc);
1428 if (seq_geq (tc->snd_una, tc->snd_congestion))
1430 tcp_retransmit_timer_update (tc);
1432 /* If spurious return, we've already updated everything */
1433 if (tcp_cc_recover (tc))
1435 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1439 tc->snd_nxt = tc->snd_una_max;
1441 /* Treat as congestion avoidance ack */
1442 tcp_cc_rcv_ack (tc);
1447 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1450 /* XXX limit this only to first partial ack? */
1451 tcp_retransmit_timer_update (tc);
1453 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1454 * reset dupacks to 0. Also needed if in congestion recovery */
1455 tc->rcv_dupacks = 0;
1457 /* Post RTO timeout don't try anything fancy */
1458 if (tcp_in_recovery (tc))
1460 tcp_cc_rcv_ack (tc);
1461 transport_add_tx_event (&tc->connection);
1465 /* Remove retransmitted bytes that have been delivered */
1466 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1468 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1469 >= tc->sack_sb.last_bytes_delivered
1470 || (tc->flags & TCP_CONN_FINSNT));
1472 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1473 * remove sacked bytes delivered */
1474 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1476 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1477 - tc->sack_sb.last_bytes_delivered;
1478 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1479 tc->snd_rxt_bytes -= rxt_delivered;
1483 /* Apparently all retransmitted holes have been acked */
1484 tc->snd_rxt_bytes = 0;
1485 tc->sack_sb.high_rxt = tc->snd_una;
1490 tcp_fastrecovery_first_on (tc);
1491 /* Reuse last bytes delivered to track total bytes acked */
1492 tc->sack_sb.last_bytes_delivered += tc->bytes_acked;
1493 if (tc->snd_rxt_bytes > tc->bytes_acked)
1494 tc->snd_rxt_bytes -= tc->bytes_acked;
1496 tc->snd_rxt_bytes = 0;
1499 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1502 * Since this was a partial ack, try to retransmit some more data
1504 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1508 * Process incoming ACK
1511 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1512 tcp_header_t * th, u32 * error)
1514 u32 prev_snd_wnd, prev_snd_una;
1517 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1519 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1520 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1522 /* When we entered recovery, we reset snd_nxt to snd_una. Seems peer
1523 * still has the data so accept the ack */
1524 if (tcp_in_recovery (tc)
1525 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_congestion))
1527 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1528 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
1529 tc->snd_una_max = tc->snd_nxt;
1533 /* If we have outstanding data and this is within the window, accept it,
1534 * probably retransmit has timed out. Otherwise ACK segment and then
1536 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1538 tcp_program_ack (wrk, tc);
1539 *error = TCP_ERROR_ACK_FUTURE;
1540 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1541 vnet_buffer (b)->tcp.ack_number);
1545 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1546 vnet_buffer (b)->tcp.ack_number);
1548 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1551 /* If old ACK, probably it's an old dupack */
1552 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1554 *error = TCP_ERROR_ACK_OLD;
1555 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1556 vnet_buffer (b)->tcp.ack_number);
1557 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1558 tcp_cc_handle_event (tc, 1);
1559 /* Don't drop yet */
1564 * Looks okay, process feedback
1567 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1568 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1570 prev_snd_wnd = tc->snd_wnd;
1571 prev_snd_una = tc->snd_una;
1572 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1573 vnet_buffer (b)->tcp.ack_number,
1574 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1575 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1576 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1577 tcp_validate_txf_size (tc, tc->bytes_acked);
1579 if (tc->bytes_acked)
1581 tcp_program_dequeue (wrk, tc);
1582 tcp_update_rtt (tc, vnet_buffer (b)->tcp.ack_number);
1585 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1588 * Check if we have congestion event
1591 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1593 tcp_cc_handle_event (tc, is_dack);
1594 if (!tcp_in_cong_recovery (tc))
1596 *error = TCP_ERROR_ACK_DUP;
1597 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1603 * Update congestion control (slow start/congestion avoidance)
1605 tcp_cc_update (tc, b);
1606 *error = TCP_ERROR_ACK_OK;
1611 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1613 if (!tcp_disconnect_pending (tc))
1615 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1616 tcp_disconnect_pending_on (tc);
1621 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1623 u32 thread_index, *pending_disconnects;
1624 tcp_connection_t *tc;
1627 if (!vec_len (wrk->pending_disconnects))
1630 thread_index = wrk->vm->thread_index;
1631 pending_disconnects = wrk->pending_disconnects;
1632 for (i = 0; i < vec_len (pending_disconnects); i++)
1634 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1635 tcp_disconnect_pending_off (tc);
1636 stream_session_disconnect_notify (&tc->connection);
1638 _vec_len (wrk->pending_disconnects) = 0;
1642 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1645 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1646 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1647 /* Account for the FIN if nothing else was received */
1648 if (vnet_buffer (b)->tcp.data_len == 0)
1650 tcp_program_ack (wrk, tc);
1651 tc->state = TCP_STATE_CLOSE_WAIT;
1652 tcp_program_disconnect (wrk, tc);
1653 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1654 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc);
1655 *error = TCP_ERROR_FIN_RCVD;
1659 tcp_sack_vector_is_sane (sack_block_t * sacks)
1662 for (i = 1; i < vec_len (sacks); i++)
1664 if (sacks[i - 1].end == sacks[i].start)
1671 * Build SACK list as per RFC2018.
1673 * Makes sure the first block contains the segment that generated the current
1674 * ACK and the following ones are the ones most recently reported in SACK
1677 * @param tc TCP connection for which the SACK list is updated
1678 * @param start Start sequence number of the newest SACK block
1679 * @param end End sequence of the newest SACK block
1682 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1684 sack_block_t *new_list = 0, *block = 0;
1687 /* If the first segment is ooo add it to the list. Last write might've moved
1688 * rcv_nxt over the first segment. */
1689 if (seq_lt (tc->rcv_nxt, start))
1691 vec_add2 (new_list, block, 1);
1692 block->start = start;
1696 /* Find the blocks still worth keeping. */
1697 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1699 /* Discard if rcv_nxt advanced beyond current block */
1700 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1703 /* Merge or drop if segment overlapped by the new segment */
1704 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1705 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1707 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1708 new_list[0].start = tc->snd_sacks[i].start;
1709 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1710 new_list[0].end = tc->snd_sacks[i].end;
1714 /* Save to new SACK list if we have space. */
1715 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1717 vec_add1 (new_list, tc->snd_sacks[i]);
1721 clib_warning ("sack discarded");
1725 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1727 /* Replace old vector with new one */
1728 vec_free (tc->snd_sacks);
1729 tc->snd_sacks = new_list;
1731 /* Segments should not 'touch' */
1732 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1736 tcp_sack_list_bytes (tcp_connection_t * tc)
1739 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1740 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1744 /** Enqueue data for delivery to application */
1746 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1749 int written, error = TCP_ERROR_ENQUEUED;
1751 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1753 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1754 1 /* queue event */ , 1);
1756 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1758 /* Update rcv_nxt */
1759 if (PREDICT_TRUE (written == data_len))
1761 tc->rcv_nxt += written;
1763 /* If more data written than expected, account for out-of-order bytes. */
1764 else if (written > data_len)
1766 tc->rcv_nxt += written;
1767 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1769 else if (written > 0)
1771 /* We've written something but FIFO is probably full now */
1772 tc->rcv_nxt += written;
1773 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1777 return TCP_ERROR_FIFO_FULL;
1780 /* Update SACK list if need be */
1781 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1783 /* Remove SACK blocks that have been delivered */
1784 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1790 /** Enqueue out-of-order data */
1792 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1795 stream_session_t *s0;
1798 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1801 /* Enqueue out-of-order data with relative offset */
1802 rv = session_enqueue_stream_connection (&tc->connection, b,
1803 vnet_buffer (b)->tcp.seq_number -
1804 tc->rcv_nxt, 0 /* queue event */ ,
1807 /* Nothing written */
1810 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1811 return TCP_ERROR_FIFO_FULL;
1814 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1816 /* Update SACK list if in use */
1817 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1819 ooo_segment_t *newest;
1822 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1824 /* Get the newest segment from the fifo */
1825 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1828 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1829 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1830 start = tc->rcv_nxt + offset;
1831 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1832 tcp_update_sack_list (tc, start, end);
1833 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1834 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1838 return TCP_ERROR_ENQUEUED_OOO;
1842 * Check if ACK could be delayed. If ack can be delayed, it should return
1843 * true for a full frame. If we're always acking return 0.
1846 tcp_can_delack (tcp_connection_t * tc)
1848 /* Send ack if ... */
1850 /* just sent a rcv wnd 0 */
1851 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1852 /* constrained to send ack */
1853 || (tc->flags & TCP_CONN_SNDACK) != 0
1854 /* we're almost out of tx wnd */
1855 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1862 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1864 u32 discard, first = b->current_length;
1865 vlib_main_t *vm = vlib_get_main ();
1867 /* Handle multi-buffer segments */
1868 if (n_bytes_to_drop > b->current_length)
1870 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1874 discard = clib_min (n_bytes_to_drop, b->current_length);
1875 vlib_buffer_advance (b, discard);
1876 b = vlib_get_buffer (vm, b->next_buffer);
1877 n_bytes_to_drop -= discard;
1879 while (n_bytes_to_drop);
1880 if (n_bytes_to_drop > first)
1881 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1884 vlib_buffer_advance (b, n_bytes_to_drop);
1885 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1890 * Receive buffer for connection and handle acks
1892 * It handles both in order or out-of-order data.
1895 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1898 u32 error, n_bytes_to_drop, n_data_bytes;
1900 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1901 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1902 ASSERT (n_data_bytes);
1904 /* Handle out-of-order data */
1905 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1907 /* Old sequence numbers allowed through because they overlapped
1909 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1911 /* Completely in the past (possible retransmit). Ack
1912 * retransmissions since we may not have any data to send */
1913 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1915 tcp_program_ack (wrk, tc);
1916 error = TCP_ERROR_SEGMENT_OLD;
1920 /* Chop off the bytes in the past and see if what is left
1921 * can be enqueued in order */
1922 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1923 n_data_bytes -= n_bytes_to_drop;
1924 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1925 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1927 error = TCP_ERROR_SEGMENT_OLD;
1933 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1934 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1935 tcp_program_dupack (wrk, tc);
1936 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1942 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1943 * segments can be enqueued after fifo tail offset changes. */
1944 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1945 if (tcp_can_delack (tc))
1947 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1948 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1952 tcp_program_ack (wrk, tc);
1960 tcp_header_t tcp_header;
1961 tcp_connection_t tcp_connection;
1965 format_tcp_rx_trace (u8 * s, va_list * args)
1967 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1968 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1969 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1970 u32 indent = format_get_indent (s);
1972 s = format (s, "%U\n%U%U",
1973 format_tcp_header, &t->tcp_header, 128,
1974 format_white_space, indent,
1975 format_tcp_connection, &t->tcp_connection, 1);
1981 format_tcp_rx_trace_short (u8 * s, va_list * args)
1983 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1984 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1985 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1987 s = format (s, "%d -> %d (%U)",
1988 clib_net_to_host_u16 (t->tcp_header.dst_port),
1989 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
1990 t->tcp_connection.state);
1996 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1997 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
2001 clib_memcpy_fast (&t0->tcp_connection, tc0,
2002 sizeof (t0->tcp_connection));
2006 th0 = tcp_buffer_hdr (b0);
2008 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2012 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2013 vlib_frame_t * frame, u8 is_ip4)
2017 n_left = frame->n_vectors;
2018 from = vlib_frame_vector_args (frame);
2022 tcp_connection_t *tc0;
2029 b0 = vlib_get_buffer (vm, bi0);
2031 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2033 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2034 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2036 th0 = tcp_buffer_hdr (b0);
2037 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2046 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2047 u8 is_ip4, u32 evt, u32 val)
2050 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2052 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2055 #define tcp_maybe_inc_counter(node_id, err, count) \
2057 if (next0 != tcp_next_drop (is_ip4)) \
2058 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2059 tcp6_##node_id##_node.index, is_ip4, err, \
2062 #define tcp_inc_counter(node_id, err, count) \
2063 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2064 tcp6_##node_id##_node.index, is_ip4, \
2066 #define tcp_maybe_inc_err_counter(cnts, err) \
2068 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2070 #define tcp_inc_err_counter(cnts, err, val) \
2074 #define tcp_store_err_counters(node_id, cnts) \
2077 for (i = 0; i < TCP_N_ERROR; i++) \
2079 tcp_inc_counter(node_id, i, cnts[i]); \
2084 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2085 vlib_frame_t * frame, int is_ip4)
2087 u32 thread_index = vm->thread_index, errors = 0;
2088 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2089 u32 n_left_from, *from, *first_buffer;
2090 u16 err_counters[TCP_N_ERROR] = { 0 };
2093 if (node->flags & VLIB_NODE_FLAG_TRACE)
2094 tcp_established_trace_frame (vm, node, frame, is_ip4);
2096 first_buffer = from = vlib_frame_vector_args (frame);
2097 n_left_from = frame->n_vectors;
2099 while (n_left_from > 0)
2101 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2103 tcp_header_t *th0 = 0;
2104 tcp_connection_t *tc0;
2106 if (n_left_from > 1)
2109 pb = vlib_get_buffer (vm, from[1]);
2110 vlib_prefetch_buffer_header (pb, LOAD);
2111 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2118 b0 = vlib_get_buffer (vm, bi0);
2119 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2122 if (PREDICT_FALSE (tc0 == 0))
2124 error0 = TCP_ERROR_INVALID_CONNECTION;
2128 th0 = tcp_buffer_hdr (b0);
2129 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
2130 * dangling reference. */
2131 is_fin = tcp_is_fin (th0);
2133 /* SYNs, FINs and data consume sequence numbers */
2134 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2135 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
2137 /* TODO header prediction fast path */
2139 /* 1-4: check SEQ, RST, SYN */
2140 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2142 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2146 /* 5: check the ACK field */
2147 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2150 /* 6: check the URG bit TODO */
2152 /* 7: process the segment text */
2153 if (vnet_buffer (b0)->tcp.data_len)
2154 error0 = tcp_segment_rcv (wrk, tc0, b0);
2156 /* 8: check the FIN bit */
2157 if (PREDICT_FALSE (is_fin))
2158 tcp_rcv_fin (wrk, tc0, b0, &error0);
2161 tcp_inc_err_counter (err_counters, error0, 1);
2164 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2166 err_counters[TCP_ERROR_EVENT_FIFO_FULL] = errors;
2167 tcp_store_err_counters (established, err_counters);
2168 tcp_handle_postponed_dequeues (wrk);
2169 tcp_handle_disconnects (wrk);
2170 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2172 return frame->n_vectors;
2176 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2177 vlib_frame_t * from_frame)
2179 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2183 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2184 vlib_frame_t * from_frame)
2186 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2190 VLIB_REGISTER_NODE (tcp4_established_node) =
2192 .function = tcp4_established,
2193 .name = "tcp4-established",
2194 /* Takes a vector of packets. */
2195 .vector_size = sizeof (u32),
2196 .n_errors = TCP_N_ERROR,
2197 .error_strings = tcp_error_strings,
2198 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2201 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2202 foreach_tcp_state_next
2205 .format_trace = format_tcp_rx_trace_short,
2209 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
2212 VLIB_REGISTER_NODE (tcp6_established_node) =
2214 .function = tcp6_established,
2215 .name = "tcp6-established",
2216 /* Takes a vector of packets. */
2217 .vector_size = sizeof (u32),
2218 .n_errors = TCP_N_ERROR,
2219 .error_strings = tcp_error_strings,
2220 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2223 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2224 foreach_tcp_state_next
2227 .format_trace = format_tcp_rx_trace_short,
2232 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
2234 vlib_node_registration_t tcp4_syn_sent_node;
2235 vlib_node_registration_t tcp6_syn_sent_node;
2238 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2240 transport_connection_t *tmp = 0;
2247 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2250 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2251 && (tc->state == TCP_STATE_LISTEN
2252 || tc->c_rmt_port == hdr->src_port));
2256 handle = session_lookup_half_open_handle (&tc->connection);
2257 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2258 tc->c_proto, tc->c_is_ip4);
2262 if (tmp->lcl_port == hdr->dst_port
2263 && tmp->rmt_port == hdr->src_port)
2265 TCP_DBG ("half-open is valid!");
2273 * Lookup transport connection
2275 static tcp_connection_t *
2276 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2280 transport_connection_t *tconn;
2281 tcp_connection_t *tc;
2286 ip4 = vlib_buffer_get_current (b);
2287 tcp = ip4_next_header (ip4);
2288 tconn = session_lookup_connection_wt4 (fib_index,
2293 TRANSPORT_PROTO_TCP,
2294 thread_index, &is_filtered);
2295 tc = tcp_get_connection_from_transport (tconn);
2296 ASSERT (tcp_lookup_is_valid (tc, tcp));
2301 ip6 = vlib_buffer_get_current (b);
2302 tcp = ip6_next_header (ip6);
2303 tconn = session_lookup_connection_wt6 (fib_index,
2308 TRANSPORT_PROTO_TCP,
2309 thread_index, &is_filtered);
2310 tc = tcp_get_connection_from_transport (tconn);
2311 ASSERT (tcp_lookup_is_valid (tc, tcp));
2317 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2318 vlib_frame_t * from_frame, int is_ip4)
2320 tcp_main_t *tm = vnet_get_tcp_main ();
2321 u32 n_left_from, *from, *first_buffer, errors = 0;
2322 u32 my_thread_index = vm->thread_index;
2323 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2325 from = first_buffer = vlib_frame_vector_args (from_frame);
2326 n_left_from = from_frame->n_vectors;
2328 while (n_left_from > 0)
2330 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2331 tcp_connection_t *tc0, *new_tc0;
2332 tcp_header_t *tcp0 = 0;
2340 b0 = vlib_get_buffer (vm, bi0);
2342 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2343 if (PREDICT_FALSE (tc0 == 0))
2345 error0 = TCP_ERROR_INVALID_CONNECTION;
2349 /* Half-open completed recently but the connection was't removed
2350 * yet by the owning thread */
2351 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2353 /* Make sure the connection actually exists */
2354 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2355 my_thread_index, is_ip4));
2359 ack0 = vnet_buffer (b0)->tcp.ack_number;
2360 seq0 = vnet_buffer (b0)->tcp.seq_number;
2361 tcp0 = tcp_buffer_hdr (b0);
2363 /* Crude check to see if the connection handle does not match
2364 * the packet. Probably connection just switched to established */
2365 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2366 || tcp0->src_port != tc0->c_rmt_port))
2368 error0 = TCP_ERROR_INVALID_CONNECTION;
2372 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2373 && !tcp_syn (tcp0)))
2375 error0 = TCP_ERROR_SEGMENT_INVALID;
2379 /* SYNs, FINs and data consume sequence numbers */
2380 vnet_buffer (b0)->tcp.seq_end =
2381 seq0 + tcp_is_syn (tcp0) + tcp_is_fin (tcp0) +
2382 vnet_buffer (b0)->tcp.data_len;
2385 * 1. check the ACK bit
2389 * If the ACK bit is set
2390 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2391 * the RST bit is set, if so drop the segment and return)
2392 * <SEQ=SEG.ACK><CTL=RST>
2393 * and discard the segment. Return.
2394 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2398 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2400 if (!tcp_rst (tcp0))
2401 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2402 error0 = TCP_ERROR_RCV_WND;
2406 /* Make sure ACK is valid */
2407 if (seq_gt (tc0->snd_una, ack0))
2409 error0 = TCP_ERROR_ACK_INVALID;
2415 * 2. check the RST bit
2420 /* If ACK is acceptable, signal client that peer is not
2421 * willing to accept connection and drop connection*/
2423 tcp_connection_reset (tc0);
2424 error0 = TCP_ERROR_RST_RCVD;
2429 * 3. check the security and precedence (skipped)
2433 * 4. check the SYN bit
2436 /* No SYN flag. Drop. */
2437 if (!tcp_syn (tcp0))
2439 clib_warning ("not synack");
2440 error0 = TCP_ERROR_SEGMENT_INVALID;
2445 if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1))
2447 clib_warning ("options parse fail");
2448 error0 = TCP_ERROR_OPTIONS;
2452 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2453 * current thread pool. */
2454 pool_get (tm->connections[my_thread_index], new_tc0);
2455 clib_memcpy_fast (new_tc0, tc0, sizeof (*new_tc0));
2456 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2457 new_tc0->c_thread_index = my_thread_index;
2458 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2459 new_tc0->irs = seq0;
2460 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
2461 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2462 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2464 /* If this is not the owning thread, wait for syn retransmit to
2465 * expire and cleanup then */
2466 if (tcp_half_open_connection_cleanup (tc0))
2467 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2469 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2471 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2472 new_tc0->tsval_recent_age = tcp_time_now ();
2475 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2476 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2478 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2479 << new_tc0->snd_wscale;
2480 new_tc0->snd_wl1 = seq0;
2481 new_tc0->snd_wl2 = ack0;
2483 tcp_connection_init_vars (new_tc0);
2485 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2486 if (PREDICT_TRUE (tcp_ack (tcp0)))
2488 /* Our SYN is ACKed: we have iss < ack = snd_una */
2490 /* TODO Dequeue acknowledged segments if we support Fast Open */
2491 new_tc0->snd_una = ack0;
2492 new_tc0->state = TCP_STATE_ESTABLISHED;
2494 /* Make sure las is initialized for the wnd computation */
2495 new_tc0->rcv_las = new_tc0->rcv_nxt;
2497 /* Notify app that we have connection. If session layer can't
2498 * allocate session send reset */
2499 if (session_stream_connect_notify (&new_tc0->connection, 0))
2501 clib_warning ("connect notify fail");
2502 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2503 tcp_connection_cleanup (new_tc0);
2507 new_tc0->tx_fifo_size =
2508 transport_tx_fifo_size (&new_tc0->connection);
2509 /* Update rtt with the syn-ack sample */
2510 tcp_estimate_initial_rtt (new_tc0);
2511 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2512 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2514 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2517 new_tc0->state = TCP_STATE_SYN_RCVD;
2519 /* Notify app that we have connection */
2520 if (session_stream_connect_notify (&new_tc0->connection, 0))
2522 tcp_connection_cleanup (new_tc0);
2523 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2524 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2528 new_tc0->tx_fifo_size =
2529 transport_tx_fifo_size (&new_tc0->connection);
2530 new_tc0->rtt_ts = 0;
2531 tcp_init_snd_vars (new_tc0);
2532 tcp_send_synack (new_tc0);
2533 error0 = TCP_ERROR_SYNS_RCVD;
2537 /* Read data, if any */
2538 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2540 clib_warning ("rcvd data in syn-sent");
2541 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2542 if (error0 == TCP_ERROR_ACK_OK)
2543 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2547 tcp_program_ack (wrk, new_tc0);
2552 tcp_inc_counter (syn_sent, error0, 1);
2553 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2555 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2556 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2557 clib_memcpy_fast (&t0->tcp_connection, tc0,
2558 sizeof (t0->tcp_connection));
2562 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2564 tcp_inc_counter (syn_sent, TCP_ERROR_EVENT_FIFO_FULL, errors);
2565 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2567 return from_frame->n_vectors;
2571 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2572 vlib_frame_t * from_frame)
2574 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2578 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2579 vlib_frame_t * from_frame)
2581 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2585 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2587 .function = tcp4_syn_sent,
2588 .name = "tcp4-syn-sent",
2589 /* Takes a vector of packets. */
2590 .vector_size = sizeof (u32),
2591 .n_errors = TCP_N_ERROR,
2592 .error_strings = tcp_error_strings,
2593 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2596 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2597 foreach_tcp_state_next
2600 .format_trace = format_tcp_rx_trace_short,
2604 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2607 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2609 .function = tcp6_syn_sent_rcv,
2610 .name = "tcp6-syn-sent",
2611 /* Takes a vector of packets. */
2612 .vector_size = sizeof (u32),
2613 .n_errors = TCP_N_ERROR,
2614 .error_strings = tcp_error_strings,
2615 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2618 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2619 foreach_tcp_state_next
2622 .format_trace = format_tcp_rx_trace_short,
2626 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2628 vlib_node_registration_t tcp4_rcv_process_node;
2629 vlib_node_registration_t tcp6_rcv_process_node;
2632 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2633 * as per RFC793 p. 64
2636 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2637 vlib_frame_t * from_frame, int is_ip4)
2639 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2640 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2641 u32 n_left_from, *from;
2643 from = first_buffer = vlib_frame_vector_args (from_frame);
2644 n_left_from = from_frame->n_vectors;
2646 while (n_left_from > 0)
2648 u32 bi0, error0 = TCP_ERROR_NONE;
2649 tcp_header_t *tcp0 = 0;
2650 tcp_connection_t *tc0;
2658 b0 = vlib_get_buffer (vm, bi0);
2659 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2661 if (PREDICT_FALSE (tc0 == 0))
2663 error0 = TCP_ERROR_INVALID_CONNECTION;
2667 tcp0 = tcp_buffer_hdr (b0);
2668 is_fin0 = tcp_is_fin (tcp0);
2670 /* SYNs, FINs and data consume sequence numbers */
2671 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2672 + tcp_is_syn (tcp0) + is_fin0 + vnet_buffer (b0)->tcp.data_len;
2676 tcp_connection_t *tmp;
2677 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2679 if (tmp->state != tc0->state)
2681 clib_warning ("state changed");
2687 * Special treatment for CLOSED
2689 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2691 error0 = TCP_ERROR_CONNECTION_CLOSED;
2696 * For all other states (except LISTEN)
2699 /* 1-4: check SEQ, RST, SYN */
2700 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2703 /* 5: check the ACK field */
2706 case TCP_STATE_SYN_RCVD:
2708 * If the segment acknowledgment is not acceptable, form a
2710 * <SEQ=SEG.ACK><CTL=RST>
2713 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2715 TCP_DBG ("connection not accepted");
2716 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2717 error0 = TCP_ERROR_ACK_INVALID;
2721 /* Update rtt and rto */
2722 tcp_estimate_initial_rtt (tc0);
2724 /* Switch state to ESTABLISHED */
2725 tc0->state = TCP_STATE_ESTABLISHED;
2726 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2728 /* Initialize session variables */
2729 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2730 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2731 << tc0->rcv_opts.wscale;
2732 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2733 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2735 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2736 tcp_retransmit_timer_reset (tc0);
2737 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2738 stream_session_accept_notify (&tc0->connection);
2739 error0 = TCP_ERROR_ACK_OK;
2741 case TCP_STATE_ESTABLISHED:
2742 /* We can get packets in established state here because they
2743 * were enqueued before state change */
2744 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2748 case TCP_STATE_FIN_WAIT_1:
2749 /* In addition to the processing for the ESTABLISHED state, if
2750 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2751 * continue processing in that state. */
2752 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2755 /* Still have to send the FIN */
2756 if (tc0->flags & TCP_CONN_FINPNDG)
2758 /* TX fifo finally drained */
2759 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2762 /* If FIN is ACKed */
2763 else if (tc0->snd_una == tc0->snd_una_max)
2765 tc0->state = TCP_STATE_FIN_WAIT_2;
2766 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2768 /* Stop all retransmit timers because we have nothing more
2769 * to send. Enable waitclose though because we're willing to
2770 * wait for peer's FIN but not indefinitely. */
2771 tcp_connection_timers_reset (tc0);
2772 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2774 /* Don't try to deq the FIN acked */
2775 if (tc0->burst_acked > 1)
2776 stream_session_dequeue_drop (&tc0->connection,
2777 tc0->burst_acked - 1);
2778 tc0->burst_acked = 0;
2781 case TCP_STATE_FIN_WAIT_2:
2782 /* In addition to the processing for the ESTABLISHED state, if
2783 * the retransmission queue is empty, the user's CLOSE can be
2784 * acknowledged ("ok") but do not delete the TCB. */
2785 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2787 tc0->burst_acked = 0;
2789 case TCP_STATE_CLOSE_WAIT:
2790 /* Do the same processing as for the ESTABLISHED state. */
2791 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2794 if (tc0->flags & TCP_CONN_FINPNDG)
2796 /* TX fifo finally drained */
2797 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2800 tcp_connection_timers_reset (tc0);
2801 tc0->state = TCP_STATE_LAST_ACK;
2802 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2806 case TCP_STATE_CLOSING:
2807 /* In addition to the processing for the ESTABLISHED state, if
2808 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2809 * otherwise ignore the segment. */
2810 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2813 tc0->state = TCP_STATE_TIME_WAIT;
2814 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2815 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2819 case TCP_STATE_LAST_ACK:
2820 /* The only thing that [should] arrive in this state is an
2821 * acknowledgment of our FIN. If our FIN is now acknowledged,
2822 * delete the TCB, enter the CLOSED state, and return. */
2824 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2826 error0 = TCP_ERROR_ACK_INVALID;
2829 error0 = TCP_ERROR_ACK_OK;
2830 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2831 /* Apparently our ACK for the peer's FIN was lost */
2832 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2838 tc0->state = TCP_STATE_CLOSED;
2839 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2841 /* Don't free the connection from the data path since
2842 * we can't ensure that we have no packets already enqueued
2843 * to output. Rely instead on the waitclose timer */
2844 tcp_connection_timers_reset (tc0);
2845 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, 1);
2850 case TCP_STATE_TIME_WAIT:
2851 /* The only thing that can arrive in this state is a
2852 * retransmission of the remote FIN. Acknowledge it, and restart
2853 * the 2 MSL timeout. */
2855 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2858 tcp_program_ack (wrk, tc0);
2859 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2867 /* 6: check the URG bit TODO */
2869 /* 7: process the segment text */
2872 case TCP_STATE_ESTABLISHED:
2873 case TCP_STATE_FIN_WAIT_1:
2874 case TCP_STATE_FIN_WAIT_2:
2875 if (vnet_buffer (b0)->tcp.data_len)
2876 error0 = tcp_segment_rcv (wrk, tc0, b0);
2880 case TCP_STATE_CLOSE_WAIT:
2881 case TCP_STATE_CLOSING:
2882 case TCP_STATE_LAST_ACK:
2883 case TCP_STATE_TIME_WAIT:
2884 /* This should not occur, since a FIN has been received from the
2885 * remote side. Ignore the segment text. */
2889 /* 8: check the FIN bit */
2895 case TCP_STATE_ESTABLISHED:
2896 case TCP_STATE_SYN_RCVD:
2897 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2898 tcp_connection_timers_reset (tc0);
2900 stream_session_disconnect_notify (&tc0->connection);
2901 tc0->state = TCP_STATE_CLOSE_WAIT;
2902 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2904 case TCP_STATE_CLOSE_WAIT:
2905 case TCP_STATE_CLOSING:
2906 case TCP_STATE_LAST_ACK:
2909 case TCP_STATE_FIN_WAIT_1:
2910 tc0->state = TCP_STATE_CLOSING;
2911 tcp_program_ack (wrk, tc0);
2912 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2913 /* Wait for ACK but not forever */
2914 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2916 case TCP_STATE_FIN_WAIT_2:
2917 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2918 tc0->state = TCP_STATE_TIME_WAIT;
2919 tcp_connection_timers_reset (tc0);
2920 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2921 tcp_program_ack (wrk, tc0);
2922 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2924 case TCP_STATE_TIME_WAIT:
2925 /* Remain in the TIME-WAIT state. Restart the time-wait
2928 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2931 error0 = TCP_ERROR_FIN_RCVD;
2932 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2936 tcp_inc_counter (rcv_process, error0, 1);
2937 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2939 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2940 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2944 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2946 tcp_inc_counter (rcv_process, TCP_ERROR_EVENT_FIFO_FULL, errors);
2947 tcp_handle_postponed_dequeues (wrk);
2948 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2950 return from_frame->n_vectors;
2954 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2955 vlib_frame_t * from_frame)
2957 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2961 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2962 vlib_frame_t * from_frame)
2964 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2968 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2970 .function = tcp4_rcv_process,
2971 .name = "tcp4-rcv-process",
2972 /* Takes a vector of packets. */
2973 .vector_size = sizeof (u32),
2974 .n_errors = TCP_N_ERROR,
2975 .error_strings = tcp_error_strings,
2976 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2979 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2980 foreach_tcp_state_next
2983 .format_trace = format_tcp_rx_trace_short,
2987 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2990 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2992 .function = tcp6_rcv_process,
2993 .name = "tcp6-rcv-process",
2994 /* Takes a vector of packets. */
2995 .vector_size = sizeof (u32),
2996 .n_errors = TCP_N_ERROR,
2997 .error_strings = tcp_error_strings,
2998 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3001 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3002 foreach_tcp_state_next
3005 .format_trace = format_tcp_rx_trace_short,
3009 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
3011 vlib_node_registration_t tcp4_listen_node;
3012 vlib_node_registration_t tcp6_listen_node;
3015 * LISTEN state processing as per RFC 793 p. 65
3018 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3019 vlib_frame_t * from_frame, int is_ip4)
3021 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3022 u32 my_thread_index = vm->thread_index;
3024 from = first_buffer = vlib_frame_vector_args (from_frame);
3025 n_left_from = from_frame->n_vectors;
3027 while (n_left_from > 0)
3032 tcp_header_t *th0 = 0;
3033 tcp_connection_t *lc0;
3036 tcp_connection_t *child0;
3037 u32 error0 = TCP_ERROR_NONE;
3043 b0 = vlib_get_buffer (vm, bi0);
3044 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3048 ip40 = vlib_buffer_get_current (b0);
3049 th0 = ip4_next_header (ip40);
3053 ip60 = vlib_buffer_get_current (b0);
3054 th0 = ip6_next_header (ip60);
3057 /* Create child session. For syn-flood protection use filter */
3059 /* 1. first check for an RST: handled in dispatch */
3060 /* if (tcp_rst (th0))
3064 /* 2. second check for an ACK: handled in dispatch */
3065 /* if (tcp_ack (th0))
3067 tcp_send_reset (b0, is_ip4);
3072 /* 3. check for a SYN (did that already) */
3074 /* Make sure connection wasn't just created */
3075 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3077 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3079 error0 = TCP_ERROR_CREATE_EXISTS;
3083 /* Create child session and send SYN-ACK */
3084 child0 = tcp_connection_new (my_thread_index);
3085 child0->c_lcl_port = th0->dst_port;
3086 child0->c_rmt_port = th0->src_port;
3087 child0->c_is_ip4 = is_ip4;
3088 child0->state = TCP_STATE_SYN_RCVD;
3089 child0->c_fib_index = lc0->c_fib_index;
3093 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3094 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3098 clib_memcpy_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3099 sizeof (ip6_address_t));
3100 clib_memcpy_fast (&child0->c_rmt_ip6, &ip60->src_address,
3101 sizeof (ip6_address_t));
3104 if (tcp_options_parse (th0, &child0->rcv_opts, 1))
3106 clib_warning ("options parse fail");
3110 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3111 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3112 child0->rcv_las = child0->rcv_nxt;
3113 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3115 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3116 * segments are used to initialize PAWS. */
3117 if (tcp_opts_tstamp (&child0->rcv_opts))
3119 child0->tsval_recent = child0->rcv_opts.tsval;
3120 child0->tsval_recent_age = tcp_time_now ();
3123 if (tcp_opts_wscale (&child0->rcv_opts))
3124 child0->snd_wscale = child0->rcv_opts.wscale;
3126 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3127 << child0->snd_wscale;
3128 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3129 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3131 tcp_connection_init_vars (child0);
3132 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
3134 if (stream_session_accept (&child0->connection, lc0->c_s_index,
3137 clib_warning ("session accept fail");
3138 tcp_connection_cleanup (child0);
3139 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3143 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3144 tcp_send_synack (child0);
3145 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
3149 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3151 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3152 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3153 clib_memcpy_fast (&t0->tcp_connection, lc0,
3154 sizeof (t0->tcp_connection));
3157 n_syns += (error0 == TCP_ERROR_NONE);
3160 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3161 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3163 return from_frame->n_vectors;
3167 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3168 vlib_frame_t * from_frame)
3170 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3174 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3175 vlib_frame_t * from_frame)
3177 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3181 VLIB_REGISTER_NODE (tcp4_listen_node) =
3183 .function = tcp4_listen,
3184 .name = "tcp4-listen",
3185 /* Takes a vector of packets. */
3186 .vector_size = sizeof (u32),
3187 .n_errors = TCP_N_ERROR,
3188 .error_strings = tcp_error_strings,
3189 .n_next_nodes = TCP_LISTEN_N_NEXT,
3192 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3193 foreach_tcp_state_next
3196 .format_trace = format_tcp_rx_trace_short,
3200 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
3203 VLIB_REGISTER_NODE (tcp6_listen_node) =
3205 .function = tcp6_listen,
3206 .name = "tcp6-listen",
3207 /* Takes a vector of packets. */
3208 .vector_size = sizeof (u32),
3209 .n_errors = TCP_N_ERROR,
3210 .error_strings = tcp_error_strings,
3211 .n_next_nodes = TCP_LISTEN_N_NEXT,
3214 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3215 foreach_tcp_state_next
3218 .format_trace = format_tcp_rx_trace_short,
3222 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
3224 vlib_node_registration_t tcp4_input_node;
3225 vlib_node_registration_t tcp6_input_node;
3227 typedef enum _tcp_input_next
3229 TCP_INPUT_NEXT_DROP,
3230 TCP_INPUT_NEXT_LISTEN,
3231 TCP_INPUT_NEXT_RCV_PROCESS,
3232 TCP_INPUT_NEXT_SYN_SENT,
3233 TCP_INPUT_NEXT_ESTABLISHED,
3234 TCP_INPUT_NEXT_RESET,
3235 TCP_INPUT_NEXT_PUNT,
3239 #define foreach_tcp4_input_next \
3240 _ (DROP, "ip4-drop") \
3241 _ (LISTEN, "tcp4-listen") \
3242 _ (RCV_PROCESS, "tcp4-rcv-process") \
3243 _ (SYN_SENT, "tcp4-syn-sent") \
3244 _ (ESTABLISHED, "tcp4-established") \
3245 _ (RESET, "tcp4-reset") \
3246 _ (PUNT, "ip4-punt")
3248 #define foreach_tcp6_input_next \
3249 _ (DROP, "ip6-drop") \
3250 _ (LISTEN, "tcp6-listen") \
3251 _ (RCV_PROCESS, "tcp6-rcv-process") \
3252 _ (SYN_SENT, "tcp6-syn-sent") \
3253 _ (ESTABLISHED, "tcp6-established") \
3254 _ (RESET, "tcp6-reset") \
3255 _ (PUNT, "ip6-punt")
3257 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3260 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3261 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3263 tcp_connection_t *tc;
3268 for (i = 0; i < n_bufs; i++)
3270 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3272 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3273 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3275 tcp = vlib_buffer_get_current (bs[i]);
3276 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3282 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3284 if (*error == TCP_ERROR_FILTERED)
3286 *next = TCP_INPUT_NEXT_DROP;
3288 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3290 *next = TCP_INPUT_NEXT_PUNT;
3291 *error = TCP_ERROR_PUNT;
3295 *next = TCP_INPUT_NEXT_RESET;
3296 *error = TCP_ERROR_NO_LISTENER;
3300 static inline tcp_connection_t *
3301 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3304 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3305 int n_advance_bytes, n_data_bytes;
3306 transport_connection_t *tc;
3312 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3313 int ip_hdr_bytes = ip4_header_bytes (ip4);
3314 if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
3316 *error = TCP_ERROR_LENGTH;
3319 tcp = ip4_next_header (ip4);
3320 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3321 n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
3322 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3324 /* Length check. Checksum computed by ipx_local no need to compute again */
3325 if (PREDICT_FALSE (n_data_bytes < 0))
3327 *error = TCP_ERROR_LENGTH;
3331 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3332 &ip4->src_address, tcp->dst_port,
3333 tcp->src_port, TRANSPORT_PROTO_TCP,
3334 thread_index, &is_filtered);
3338 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3339 if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
3341 *error = TCP_ERROR_LENGTH;
3344 tcp = ip6_next_header (ip6);
3345 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3346 n_advance_bytes = tcp_header_bytes (tcp);
3347 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3349 n_advance_bytes += sizeof (ip6[0]);
3351 if (PREDICT_FALSE (n_data_bytes < 0))
3353 *error = TCP_ERROR_LENGTH;
3357 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3358 &ip6->src_address, tcp->dst_port,
3359 tcp->src_port, TRANSPORT_PROTO_TCP,
3360 thread_index, &is_filtered);
3363 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3364 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3365 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3366 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3367 vnet_buffer (b)->tcp.flags = 0;
3369 *error = is_filtered ? TCP_ERROR_FILTERED : *error;
3371 return tcp_get_connection_from_transport (tc);
3375 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3376 vlib_buffer_t * b, u16 * next, u32 * error)
3381 tcp = tcp_buffer_hdr (b);
3382 flags = tcp->flags & filter_flags;
3383 *next = tm->dispatch_table[tc->state][flags].next;
3384 *error = tm->dispatch_table[tc->state][flags].error;
3386 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3387 || *next == TCP_INPUT_NEXT_RESET))
3389 /* Overload tcp flags to store state */
3390 tcp_state_t state = tc->state;
3391 vnet_buffer (b)->tcp.flags = tc->state;
3393 if (*error == TCP_ERROR_DISPATCH)
3394 clib_warning ("disp error state %U flags %U", format_tcp_state,
3395 state, format_tcp_flags, (int) flags);
3400 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3401 vlib_frame_t * frame, int is_ip4)
3403 u32 n_left_from, *from, thread_index = vm->thread_index;
3404 tcp_main_t *tm = vnet_get_tcp_main ();
3405 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3406 u16 nexts[VLIB_FRAME_SIZE], *next;
3408 tcp_set_time_now (tcp_get_worker (thread_index));
3410 from = vlib_frame_vector_args (frame);
3411 n_left_from = frame->n_vectors;
3412 vlib_get_buffers (vm, from, bufs, n_left_from);
3417 while (n_left_from >= 4)
3419 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3420 tcp_connection_t *tc0, *tc1;
3423 vlib_prefetch_buffer_header (b[2], STORE);
3424 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3426 vlib_prefetch_buffer_header (b[3], STORE);
3427 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3430 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3432 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3433 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4);
3435 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3437 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3438 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3440 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3441 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3443 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3444 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3448 if (PREDICT_TRUE (tc0 != 0))
3450 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3451 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3452 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3455 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3457 if (PREDICT_TRUE (tc1 != 0))
3459 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3460 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3461 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3464 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3471 while (n_left_from > 0)
3473 tcp_connection_t *tc0;
3474 u32 error0 = TCP_ERROR_NO_LISTENER;
3476 if (n_left_from > 1)
3478 vlib_prefetch_buffer_header (b[1], STORE);
3479 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3482 next[0] = TCP_INPUT_NEXT_DROP;
3483 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3484 if (PREDICT_TRUE (tc0 != 0))
3486 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3487 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3488 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3491 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3498 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3499 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3501 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3502 return frame->n_vectors;
3506 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3507 vlib_frame_t * from_frame)
3509 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3513 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3514 vlib_frame_t * from_frame)
3516 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3520 VLIB_REGISTER_NODE (tcp4_input_node) =
3522 .function = tcp4_input,
3523 .name = "tcp4-input",
3524 /* Takes a vector of packets. */
3525 .vector_size = sizeof (u32),
3526 .n_errors = TCP_N_ERROR,
3527 .error_strings = tcp_error_strings,
3528 .n_next_nodes = TCP_INPUT_N_NEXT,
3531 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3532 foreach_tcp4_input_next
3535 .format_buffer = format_tcp_header,
3536 .format_trace = format_tcp_rx_trace,
3540 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3543 VLIB_REGISTER_NODE (tcp6_input_node) =
3545 .function = tcp6_input,
3546 .name = "tcp6-input",
3547 /* Takes a vector of packets. */
3548 .vector_size = sizeof (u32),
3549 .n_errors = TCP_N_ERROR,
3550 .error_strings = tcp_error_strings,
3551 .n_next_nodes = TCP_INPUT_N_NEXT,
3554 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3555 foreach_tcp6_input_next
3558 .format_buffer = format_tcp_header,
3559 .format_trace = format_tcp_rx_trace,
3563 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3566 tcp_dispatch_table_init (tcp_main_t * tm)
3569 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3570 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3572 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3573 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3576 #define _(t,f,n,e) \
3578 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3579 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3582 /* SYNs for new connections -> tcp-listen. */
3583 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3584 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3585 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_RST_RCVD);
3586 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3588 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3589 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3590 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3591 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3593 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3594 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3596 /* SYN-ACK for a SYN */
3597 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3599 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3600 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3601 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3603 /* ACK for for established connection -> tcp-established. */
3604 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3605 /* FIN for for established connection -> tcp-established. */
3606 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3607 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3609 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3610 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3612 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3613 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3615 /* ACK or FIN-ACK to our FIN */
3616 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3617 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3619 /* FIN in reply to our FIN from the other side */
3620 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3621 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3622 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3623 /* FIN confirming that the peer (app) has closed */
3624 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3625 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3626 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3628 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3629 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3631 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3632 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3633 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3635 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3636 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3637 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3638 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3640 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3641 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3642 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3643 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3644 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3645 TCP_ERROR_CONNECTION_CLOSED);
3649 static clib_error_t *
3650 tcp_input_init (vlib_main_t * vm)
3652 clib_error_t *error = 0;
3653 tcp_main_t *tm = vnet_get_tcp_main ();
3655 if ((error = vlib_call_init_function (vm, tcp_init)))
3658 /* Initialize dispatch table. */
3659 tcp_dispatch_table_init (tm);
3664 VLIB_INIT_FUNCTION (tcp_input_init);
3667 * fd.io coding-style-patch-verification: ON
3670 * eval: (c-set-style "gnu")