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) && seq_leq (blk->end, tc->snd_una_max))
913 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
916 /* Add block for cumulative ack */
917 if (seq_gt (ack, tc->snd_una))
919 tmp.start = tc->snd_una;
921 vec_add1 (tc->rcv_opts.sacks, tmp);
924 if (vec_len (tc->rcv_opts.sacks) == 0)
927 tcp_scoreboard_trace_add (tc, ack);
929 /* Make sure blocks are ordered */
930 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
931 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
932 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
934 tmp = tc->rcv_opts.sacks[i];
935 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
936 tc->rcv_opts.sacks[j] = tmp;
939 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
941 /* If no holes, insert the first that covers all outstanding bytes */
942 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
943 tc->snd_una, tc->snd_una_max);
944 sb->tail = scoreboard_hole_index (sb, last_hole);
945 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
946 sb->high_sacked = tmp.end;
950 /* If we have holes but snd_una_max is beyond the last hole, update
952 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
953 last_hole = scoreboard_last_hole (sb);
954 if (seq_gt (tc->snd_una_max, last_hole->end))
956 if (seq_geq (last_hole->start, sb->high_sacked))
958 last_hole->end = tc->snd_una_max;
960 /* New hole after high sacked block */
961 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
963 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
967 /* Keep track of max byte sacked for when the last hole
969 if (seq_gt (tmp.end, sb->high_sacked))
970 sb->high_sacked = tmp.end;
973 /* Walk the holes with the SACK blocks */
974 hole = pool_elt_at_index (sb->holes, sb->head);
975 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
977 blk = &tc->rcv_opts.sacks[blk_index];
978 if (seq_leq (blk->start, hole->start))
980 /* Block covers hole. Remove hole */
981 if (seq_geq (blk->end, hole->end))
983 next_hole = scoreboard_next_hole (sb, hole);
985 /* Byte accounting: snd_una needs to be advanced */
990 if (seq_lt (ack, next_hole->start))
991 sb->snd_una_adv = next_hole->start - ack;
992 sb->last_bytes_delivered +=
993 next_hole->start - hole->end;
997 ASSERT (seq_geq (sb->high_sacked, ack));
998 sb->snd_una_adv = sb->high_sacked - ack;
999 sb->last_bytes_delivered += sb->high_sacked - hole->end;
1003 scoreboard_remove_hole (sb, hole);
1006 /* Partial 'head' overlap */
1009 if (seq_gt (blk->end, hole->start))
1011 hole->start = blk->end;
1018 /* Hole must be split */
1019 if (seq_lt (blk->end, hole->end))
1021 hole_index = scoreboard_hole_index (sb, hole);
1022 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
1025 /* Pool might've moved */
1026 hole = scoreboard_get_hole (sb, hole_index);
1027 hole->end = blk->start;
1029 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
1031 else if (seq_lt (blk->start, hole->end))
1033 hole->end = blk->start;
1035 hole = scoreboard_next_hole (sb, hole);
1039 if (pool_elts (sb->holes) == 1)
1041 hole = scoreboard_first_hole (sb);
1042 if (hole->start == ack + sb->snd_una_adv
1043 && hole->end == tc->snd_una_max)
1044 scoreboard_remove_hole (sb, hole);
1047 scoreboard_update_bytes (tc, sb);
1048 sb->last_sacked_bytes = sb->sacked_bytes
1049 - (old_sacked_bytes - sb->last_bytes_delivered);
1050 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
1051 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
1052 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
1053 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
1054 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1055 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1056 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
1057 TCP_EVT_DBG (TCP_EVT_CC_SCOREBOARD, tc);
1061 * Try to update snd_wnd based on feedback received from peer.
1063 * If successful, and new window is 'effectively' 0, activate persist
1067 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1069 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1070 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1071 if (seq_lt (tc->snd_wl1, seq)
1072 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1074 tc->snd_wnd = snd_wnd;
1077 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
1079 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
1081 /* Set persist timer if not set and we just got 0 wnd */
1082 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1083 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1084 tcp_persist_timer_set (tc);
1088 tcp_persist_timer_reset (tc);
1089 if (PREDICT_FALSE (!tcp_in_recovery (tc) && tc->rto_boff > 0))
1092 tcp_update_rto (tc);
1099 * Init loss recovery/fast recovery.
1101 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1102 * updated in @ref tcp_cc_handle_event after fast retransmit
1105 tcp_cc_init_congestion (tcp_connection_t * tc)
1107 tcp_fastrecovery_on (tc);
1108 tc->snd_congestion = tc->snd_una_max;
1109 tc->cwnd_acc_bytes = 0;
1110 tc->snd_rxt_bytes = 0;
1111 tc->prev_ssthresh = tc->ssthresh;
1112 tc->prev_cwnd = tc->cwnd;
1113 tc->cc_algo->congestion (tc);
1114 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
1118 tcp_cc_recovery_exit (tcp_connection_t * tc)
1121 tcp_update_rto (tc);
1123 tc->snd_nxt = tc->snd_una_max;
1125 tcp_recovery_off (tc);
1126 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1130 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
1132 tc->cc_algo->recovered (tc);
1133 tc->snd_rxt_bytes = 0;
1134 tc->rcv_dupacks = 0;
1135 tc->snd_nxt = tc->snd_una_max;
1136 tc->snd_rxt_bytes = 0;
1139 tcp_fastrecovery_off (tc);
1140 tcp_fastrecovery_first_off (tc);
1142 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1146 tcp_cc_congestion_undo (tcp_connection_t * tc)
1148 tc->cwnd = tc->prev_cwnd;
1149 tc->ssthresh = tc->prev_ssthresh;
1150 tc->snd_nxt = tc->snd_una_max;
1151 tc->rcv_dupacks = 0;
1152 if (tcp_in_recovery (tc))
1153 tcp_cc_recovery_exit (tc);
1154 else if (tcp_in_fastrecovery (tc))
1155 tcp_cc_fastrecovery_exit (tc);
1156 ASSERT (tc->rto_boff == 0);
1157 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
1161 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1163 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1165 && tcp_opts_tstamp (&tc->rcv_opts)
1166 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1170 tcp_cc_is_spurious_fast_rxt (tcp_connection_t * tc)
1172 return (tcp_in_fastrecovery (tc)
1173 && tc->cwnd > tc->ssthresh + 3 * tc->snd_mss);
1177 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1179 return (tcp_cc_is_spurious_timeout_rxt (tc)
1180 || tcp_cc_is_spurious_fast_rxt (tc));
1184 tcp_cc_recover (tcp_connection_t * tc)
1186 ASSERT (tcp_in_cong_recovery (tc));
1187 if (tcp_cc_is_spurious_retransmit (tc))
1189 tcp_cc_congestion_undo (tc);
1193 if (tcp_in_recovery (tc))
1194 tcp_cc_recovery_exit (tc);
1195 else if (tcp_in_fastrecovery (tc))
1196 tcp_cc_fastrecovery_exit (tc);
1198 ASSERT (tc->rto_boff == 0);
1199 ASSERT (!tcp_in_cong_recovery (tc));
1200 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1205 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
1207 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1209 /* Congestion avoidance */
1210 tcp_cc_rcv_ack (tc);
1212 /* If a cumulative ack, make sure dupacks is 0 */
1213 tc->rcv_dupacks = 0;
1215 /* When dupacks hits the threshold we only enter fast retransmit if
1216 * cumulative ack covers more than snd_congestion. Should snd_una
1217 * wrap this test may fail under otherwise valid circumstances.
1218 * Therefore, proactively update snd_congestion when wrap detected. */
1220 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1221 && seq_gt (tc->snd_congestion, tc->snd_una)))
1222 tc->snd_congestion = tc->snd_una - 1;
1226 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1228 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1232 tcp_should_fastrecover (tcp_connection_t * tc)
1234 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1235 || tcp_should_fastrecover_sack (tc));
1239 tcp_program_fastretransmit (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1241 if (!(tc->flags & TCP_CONN_FRXT_PENDING))
1243 vec_add1 (wrk->pending_fast_rxt, tc->c_c_index);
1244 tc->flags |= TCP_CONN_FRXT_PENDING;
1249 tcp_do_fastretransmits (tcp_worker_ctx_t * wrk)
1251 u32 *ongoing_fast_rxt, burst_bytes, sent_bytes, thread_index;
1252 u32 max_burst_size, burst_size, n_segs = 0, n_segs_now;
1253 tcp_connection_t *tc;
1257 if (vec_len (wrk->pending_fast_rxt) == 0
1258 && vec_len (wrk->postponed_fast_rxt) == 0)
1261 thread_index = wrk->vm->thread_index;
1262 last_cpu_time = wrk->vm->clib_time.last_cpu_time;
1263 ongoing_fast_rxt = wrk->ongoing_fast_rxt;
1264 vec_append (ongoing_fast_rxt, wrk->postponed_fast_rxt);
1265 vec_append (ongoing_fast_rxt, wrk->pending_fast_rxt);
1267 _vec_len (wrk->postponed_fast_rxt) = 0;
1268 _vec_len (wrk->pending_fast_rxt) = 0;
1270 max_burst_size = VLIB_FRAME_SIZE / vec_len (ongoing_fast_rxt);
1271 max_burst_size = clib_max (max_burst_size, 1);
1273 for (i = 0; i < vec_len (ongoing_fast_rxt); i++)
1275 if (n_segs >= VLIB_FRAME_SIZE)
1277 vec_add1 (wrk->postponed_fast_rxt, ongoing_fast_rxt[i]);
1281 tc = tcp_connection_get (ongoing_fast_rxt[i], thread_index);
1282 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1284 if (!tcp_in_fastrecovery (tc))
1287 burst_size = clib_min (max_burst_size, VLIB_FRAME_SIZE - n_segs);
1288 burst_bytes = transport_connection_tx_pacer_burst (&tc->connection,
1290 burst_size = clib_min (burst_size, burst_bytes / tc->snd_mss);
1293 tcp_program_fastretransmit (wrk, tc);
1297 n_segs_now = tcp_fast_retransmit (wrk, tc, burst_size);
1298 sent_bytes = clib_min (n_segs_now * tc->snd_mss, burst_bytes);
1299 transport_connection_tx_pacer_update_bytes (&tc->connection,
1301 n_segs += n_segs_now;
1303 _vec_len (ongoing_fast_rxt) = 0;
1304 wrk->ongoing_fast_rxt = ongoing_fast_rxt;
1308 * One function to rule them all ... and in the darkness bind them
1311 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1315 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1317 if (tc->bytes_acked)
1319 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1323 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1324 * it account for the bytes that left the network.
1326 else if (is_dack && !tcp_in_recovery (tc))
1328 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1329 ASSERT (tc->snd_una != tc->snd_una_max
1330 || tc->sack_sb.last_sacked_bytes);
1334 /* Pure duplicate ack. If some data got acked, it's handled lower */
1335 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1337 ASSERT (tcp_in_fastrecovery (tc));
1338 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1341 else if (tcp_should_fastrecover (tc))
1345 ASSERT (!tcp_in_fastrecovery (tc));
1347 /* Heuristic to catch potential late dupacks
1348 * after fast retransmit exits */
1349 if (is_dack && tc->snd_una == tc->snd_congestion
1350 && timestamp_leq (tc->rcv_opts.tsecr, tc->tsecr_last_ack))
1352 tc->rcv_dupacks = 0;
1356 tcp_cc_init_congestion (tc);
1357 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1359 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1361 tc->cwnd = tc->ssthresh;
1362 scoreboard_init_high_rxt (&tc->sack_sb, tc->snd_una);
1366 /* Post retransmit update cwnd to ssthresh and account for the
1367 * three segments that have left the network and should've been
1368 * buffered at the receiver XXX */
1369 tc->cwnd = tc->ssthresh + 3 * tc->snd_mss;
1372 /* Constrain rate until we get a partial ack */
1373 pacer_wnd = clib_max (0.1 * tc->cwnd, 2 * tc->snd_mss);
1374 tcp_connection_tx_pacer_reset (tc, pacer_wnd,
1375 0 /* start bucket */ );
1376 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index),
1380 else if (!tc->bytes_acked
1381 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1383 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1389 /* Don't allow entry in fast recovery if still in recovery, for now */
1390 else if (0 && is_dack && tcp_in_recovery (tc))
1392 /* If of of the two conditions lower hold, reset dupacks because
1393 * we're probably after timeout (RFC6582 heuristics).
1394 * If Cumulative ack does not cover more than congestion threshold,
1396 * 1) The following doesn't hold: The congestion window is greater
1397 * than SMSS bytes and the difference between highest_ack
1398 * and prev_highest_ack is at most 4*SMSS bytes
1399 * 2) Echoed timestamp in the last non-dup ack does not equal the
1402 if (seq_leq (tc->snd_una, tc->snd_congestion)
1403 && ((!(tc->cwnd > tc->snd_mss
1404 && tc->bytes_acked <= 4 * tc->snd_mss))
1405 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1407 tc->rcv_dupacks = 0;
1412 if (!tc->bytes_acked)
1416 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1419 * Legitimate ACK. 1) See if we can exit recovery
1422 /* Update the pacing rate. For the first partial ack we move from
1423 * the artificially constrained rate to the one after congestion */
1424 tcp_connection_tx_pacer_update (tc);
1426 if (seq_geq (tc->snd_una, tc->snd_congestion))
1428 tcp_retransmit_timer_update (tc);
1430 /* If spurious return, we've already updated everything */
1431 if (tcp_cc_recover (tc))
1433 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1437 tc->snd_nxt = tc->snd_una_max;
1439 /* Treat as congestion avoidance ack */
1440 tcp_cc_rcv_ack (tc);
1445 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1448 /* XXX limit this only to first partial ack? */
1449 tcp_retransmit_timer_update (tc);
1451 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1452 * reset dupacks to 0. Also needed if in congestion recovery */
1453 tc->rcv_dupacks = 0;
1455 /* Post RTO timeout don't try anything fancy */
1456 if (tcp_in_recovery (tc))
1458 tcp_cc_rcv_ack (tc);
1459 transport_add_tx_event (&tc->connection);
1463 /* Remove retransmitted bytes that have been delivered */
1464 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1466 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1467 >= tc->sack_sb.last_bytes_delivered
1468 || (tc->flags & TCP_CONN_FINSNT));
1470 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1471 * remove sacked bytes delivered */
1472 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1474 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1475 - tc->sack_sb.last_bytes_delivered;
1476 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1477 tc->snd_rxt_bytes -= rxt_delivered;
1481 /* Apparently all retransmitted holes have been acked */
1482 tc->snd_rxt_bytes = 0;
1483 tc->sack_sb.high_rxt = tc->snd_una;
1488 tcp_fastrecovery_first_on (tc);
1489 /* Reuse last bytes delivered to track total bytes acked */
1490 tc->sack_sb.last_bytes_delivered += tc->bytes_acked;
1491 if (tc->snd_rxt_bytes > tc->bytes_acked)
1492 tc->snd_rxt_bytes -= tc->bytes_acked;
1494 tc->snd_rxt_bytes = 0;
1497 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1500 * Since this was a partial ack, try to retransmit some more data
1502 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1506 * Process incoming ACK
1509 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1510 tcp_header_t * th, u32 * error)
1512 u32 prev_snd_wnd, prev_snd_una;
1515 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1517 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1518 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1520 /* When we entered recovery, we reset snd_nxt to snd_una. Seems peer
1521 * still has the data so accept the ack */
1522 if (tcp_in_recovery (tc)
1523 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_congestion))
1525 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1526 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
1527 tc->snd_una_max = tc->snd_nxt;
1531 /* If we have outstanding data and this is within the window, accept it,
1532 * probably retransmit has timed out. Otherwise ACK segment and then
1534 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1536 tcp_program_ack (wrk, tc);
1537 *error = TCP_ERROR_ACK_FUTURE;
1538 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1539 vnet_buffer (b)->tcp.ack_number);
1543 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1544 vnet_buffer (b)->tcp.ack_number);
1546 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1549 /* If old ACK, probably it's an old dupack */
1550 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1552 *error = TCP_ERROR_ACK_OLD;
1553 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1554 vnet_buffer (b)->tcp.ack_number);
1555 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1556 tcp_cc_handle_event (tc, 1);
1557 /* Don't drop yet */
1562 * Looks okay, process feedback
1565 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1566 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1568 prev_snd_wnd = tc->snd_wnd;
1569 prev_snd_una = tc->snd_una;
1570 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1571 vnet_buffer (b)->tcp.ack_number,
1572 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1573 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1574 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1575 tcp_validate_txf_size (tc, tc->bytes_acked);
1577 if (tc->bytes_acked)
1579 tcp_program_dequeue (wrk, tc);
1580 tcp_update_rtt (tc, vnet_buffer (b)->tcp.ack_number);
1583 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1586 * Check if we have congestion event
1589 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1591 tcp_cc_handle_event (tc, is_dack);
1592 if (!tcp_in_cong_recovery (tc))
1594 *error = TCP_ERROR_ACK_DUP;
1595 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1601 * Update congestion control (slow start/congestion avoidance)
1603 tcp_cc_update (tc, b);
1604 *error = TCP_ERROR_ACK_OK;
1609 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1611 if (!tcp_disconnect_pending (tc))
1613 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1614 tcp_disconnect_pending_on (tc);
1619 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1621 u32 thread_index, *pending_disconnects;
1622 tcp_connection_t *tc;
1625 if (!vec_len (wrk->pending_disconnects))
1628 thread_index = wrk->vm->thread_index;
1629 pending_disconnects = wrk->pending_disconnects;
1630 for (i = 0; i < vec_len (pending_disconnects); i++)
1632 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1633 tcp_disconnect_pending_off (tc);
1634 stream_session_disconnect_notify (&tc->connection);
1636 _vec_len (wrk->pending_disconnects) = 0;
1640 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1643 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1644 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1645 /* Account for the FIN if nothing else was received */
1646 if (vnet_buffer (b)->tcp.data_len == 0)
1648 tcp_program_ack (wrk, tc);
1649 tc->state = TCP_STATE_CLOSE_WAIT;
1650 tcp_program_disconnect (wrk, tc);
1651 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1652 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc);
1653 *error = TCP_ERROR_FIN_RCVD;
1657 tcp_sack_vector_is_sane (sack_block_t * sacks)
1660 for (i = 1; i < vec_len (sacks); i++)
1662 if (sacks[i - 1].end == sacks[i].start)
1669 * Build SACK list as per RFC2018.
1671 * Makes sure the first block contains the segment that generated the current
1672 * ACK and the following ones are the ones most recently reported in SACK
1675 * @param tc TCP connection for which the SACK list is updated
1676 * @param start Start sequence number of the newest SACK block
1677 * @param end End sequence of the newest SACK block
1680 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1682 sack_block_t *new_list = 0, *block = 0;
1685 /* If the first segment is ooo add it to the list. Last write might've moved
1686 * rcv_nxt over the first segment. */
1687 if (seq_lt (tc->rcv_nxt, start))
1689 vec_add2 (new_list, block, 1);
1690 block->start = start;
1694 /* Find the blocks still worth keeping. */
1695 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1697 /* Discard if rcv_nxt advanced beyond current block */
1698 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1701 /* Merge or drop if segment overlapped by the new segment */
1702 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1703 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1705 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1706 new_list[0].start = tc->snd_sacks[i].start;
1707 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1708 new_list[0].end = tc->snd_sacks[i].end;
1712 /* Save to new SACK list if we have space. */
1713 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1715 vec_add1 (new_list, tc->snd_sacks[i]);
1719 clib_warning ("sack discarded");
1723 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1725 /* Replace old vector with new one */
1726 vec_free (tc->snd_sacks);
1727 tc->snd_sacks = new_list;
1729 /* Segments should not 'touch' */
1730 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1734 tcp_sack_list_bytes (tcp_connection_t * tc)
1737 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1738 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1742 /** Enqueue data for delivery to application */
1744 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1747 int written, error = TCP_ERROR_ENQUEUED;
1749 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1751 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1752 1 /* queue event */ , 1);
1754 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1756 /* Update rcv_nxt */
1757 if (PREDICT_TRUE (written == data_len))
1759 tc->rcv_nxt += written;
1761 /* If more data written than expected, account for out-of-order bytes. */
1762 else if (written > data_len)
1764 tc->rcv_nxt += written;
1765 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1767 else if (written > 0)
1769 /* We've written something but FIFO is probably full now */
1770 tc->rcv_nxt += written;
1771 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1775 return TCP_ERROR_FIFO_FULL;
1778 /* Update SACK list if need be */
1779 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1781 /* Remove SACK blocks that have been delivered */
1782 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1788 /** Enqueue out-of-order data */
1790 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1793 stream_session_t *s0;
1796 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1799 /* Enqueue out-of-order data with relative offset */
1800 rv = session_enqueue_stream_connection (&tc->connection, b,
1801 vnet_buffer (b)->tcp.seq_number -
1802 tc->rcv_nxt, 0 /* queue event */ ,
1805 /* Nothing written */
1808 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1809 return TCP_ERROR_FIFO_FULL;
1812 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1814 /* Update SACK list if in use */
1815 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1817 ooo_segment_t *newest;
1820 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1822 /* Get the newest segment from the fifo */
1823 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1826 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1827 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1828 start = tc->rcv_nxt + offset;
1829 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1830 tcp_update_sack_list (tc, start, end);
1831 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1832 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1836 return TCP_ERROR_ENQUEUED_OOO;
1840 * Check if ACK could be delayed. If ack can be delayed, it should return
1841 * true for a full frame. If we're always acking return 0.
1844 tcp_can_delack (tcp_connection_t * tc)
1846 /* Send ack if ... */
1848 /* just sent a rcv wnd 0 */
1849 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1850 /* constrained to send ack */
1851 || (tc->flags & TCP_CONN_SNDACK) != 0
1852 /* we're almost out of tx wnd */
1853 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1860 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1862 u32 discard, first = b->current_length;
1863 vlib_main_t *vm = vlib_get_main ();
1865 /* Handle multi-buffer segments */
1866 if (n_bytes_to_drop > b->current_length)
1868 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1872 discard = clib_min (n_bytes_to_drop, b->current_length);
1873 vlib_buffer_advance (b, discard);
1874 b = vlib_get_buffer (vm, b->next_buffer);
1875 n_bytes_to_drop -= discard;
1877 while (n_bytes_to_drop);
1878 if (n_bytes_to_drop > first)
1879 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1882 vlib_buffer_advance (b, n_bytes_to_drop);
1883 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1888 * Receive buffer for connection and handle acks
1890 * It handles both in order or out-of-order data.
1893 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1896 u32 error, n_bytes_to_drop, n_data_bytes;
1898 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1899 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1900 ASSERT (n_data_bytes);
1902 /* Handle out-of-order data */
1903 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1905 /* Old sequence numbers allowed through because they overlapped
1907 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1909 /* Completely in the past (possible retransmit). Ack
1910 * retransmissions since we may not have any data to send */
1911 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1913 tcp_program_ack (wrk, tc);
1914 error = TCP_ERROR_SEGMENT_OLD;
1918 /* Chop off the bytes in the past and see if what is left
1919 * can be enqueued in order */
1920 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1921 n_data_bytes -= n_bytes_to_drop;
1922 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1923 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1925 error = TCP_ERROR_SEGMENT_OLD;
1931 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1932 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1933 tcp_program_dupack (wrk, tc);
1934 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1940 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1941 * segments can be enqueued after fifo tail offset changes. */
1942 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1943 if (tcp_can_delack (tc))
1945 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1946 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1950 tcp_program_ack (wrk, tc);
1958 tcp_header_t tcp_header;
1959 tcp_connection_t tcp_connection;
1963 format_tcp_rx_trace (u8 * s, va_list * args)
1965 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1966 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1967 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1968 u32 indent = format_get_indent (s);
1970 s = format (s, "%U\n%U%U",
1971 format_tcp_header, &t->tcp_header, 128,
1972 format_white_space, indent,
1973 format_tcp_connection, &t->tcp_connection, 1);
1979 format_tcp_rx_trace_short (u8 * s, va_list * args)
1981 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1982 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1983 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1985 s = format (s, "%d -> %d (%U)",
1986 clib_net_to_host_u16 (t->tcp_header.dst_port),
1987 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
1988 t->tcp_connection.state);
1994 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1995 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1999 clib_memcpy_fast (&t0->tcp_connection, tc0,
2000 sizeof (t0->tcp_connection));
2004 th0 = tcp_buffer_hdr (b0);
2006 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2010 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2011 vlib_frame_t * frame, u8 is_ip4)
2015 n_left = frame->n_vectors;
2016 from = vlib_frame_vector_args (frame);
2020 tcp_connection_t *tc0;
2027 b0 = vlib_get_buffer (vm, bi0);
2029 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2031 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2032 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2034 th0 = tcp_buffer_hdr (b0);
2035 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2044 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2045 u8 is_ip4, u32 evt, u32 val)
2048 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2050 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2053 #define tcp_maybe_inc_counter(node_id, err, count) \
2055 if (next0 != tcp_next_drop (is_ip4)) \
2056 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2057 tcp6_##node_id##_node.index, is_ip4, err, \
2060 #define tcp_inc_counter(node_id, err, count) \
2061 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2062 tcp6_##node_id##_node.index, is_ip4, \
2064 #define tcp_maybe_inc_err_counter(cnts, err) \
2066 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2068 #define tcp_inc_err_counter(cnts, err, val) \
2072 #define tcp_store_err_counters(node_id, cnts) \
2075 for (i = 0; i < TCP_N_ERROR; i++) \
2077 tcp_inc_counter(node_id, i, cnts[i]); \
2082 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2083 vlib_frame_t * frame, int is_ip4)
2085 u32 thread_index = vm->thread_index, errors = 0;
2086 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2087 u32 n_left_from, *from, *first_buffer;
2088 u16 err_counters[TCP_N_ERROR] = { 0 };
2091 if (node->flags & VLIB_NODE_FLAG_TRACE)
2092 tcp_established_trace_frame (vm, node, frame, is_ip4);
2094 first_buffer = from = vlib_frame_vector_args (frame);
2095 n_left_from = frame->n_vectors;
2097 while (n_left_from > 0)
2099 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2101 tcp_header_t *th0 = 0;
2102 tcp_connection_t *tc0;
2104 if (n_left_from > 1)
2107 pb = vlib_get_buffer (vm, from[1]);
2108 vlib_prefetch_buffer_header (pb, LOAD);
2109 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2116 b0 = vlib_get_buffer (vm, bi0);
2117 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2120 if (PREDICT_FALSE (tc0 == 0))
2122 error0 = TCP_ERROR_INVALID_CONNECTION;
2126 th0 = tcp_buffer_hdr (b0);
2127 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
2128 * dangling reference. */
2129 is_fin = tcp_is_fin (th0);
2131 /* SYNs, FINs and data consume sequence numbers */
2132 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2133 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
2135 /* TODO header prediction fast path */
2137 /* 1-4: check SEQ, RST, SYN */
2138 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2140 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2144 /* 5: check the ACK field */
2145 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2148 /* 6: check the URG bit TODO */
2150 /* 7: process the segment text */
2151 if (vnet_buffer (b0)->tcp.data_len)
2152 error0 = tcp_segment_rcv (wrk, tc0, b0);
2154 /* 8: check the FIN bit */
2155 if (PREDICT_FALSE (is_fin))
2156 tcp_rcv_fin (wrk, tc0, b0, &error0);
2159 tcp_inc_err_counter (err_counters, error0, 1);
2162 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2164 err_counters[TCP_ERROR_EVENT_FIFO_FULL] = errors;
2165 tcp_store_err_counters (established, err_counters);
2166 tcp_handle_postponed_dequeues (wrk);
2167 tcp_handle_disconnects (wrk);
2168 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2170 return frame->n_vectors;
2174 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2175 vlib_frame_t * from_frame)
2177 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2181 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2182 vlib_frame_t * from_frame)
2184 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2188 VLIB_REGISTER_NODE (tcp4_established_node) =
2190 .function = tcp4_established,
2191 .name = "tcp4-established",
2192 /* Takes a vector of packets. */
2193 .vector_size = sizeof (u32),
2194 .n_errors = TCP_N_ERROR,
2195 .error_strings = tcp_error_strings,
2196 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2199 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2200 foreach_tcp_state_next
2203 .format_trace = format_tcp_rx_trace_short,
2207 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
2210 VLIB_REGISTER_NODE (tcp6_established_node) =
2212 .function = tcp6_established,
2213 .name = "tcp6-established",
2214 /* Takes a vector of packets. */
2215 .vector_size = sizeof (u32),
2216 .n_errors = TCP_N_ERROR,
2217 .error_strings = tcp_error_strings,
2218 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2221 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2222 foreach_tcp_state_next
2225 .format_trace = format_tcp_rx_trace_short,
2230 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
2232 vlib_node_registration_t tcp4_syn_sent_node;
2233 vlib_node_registration_t tcp6_syn_sent_node;
2236 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2238 transport_connection_t *tmp = 0;
2245 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2248 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2249 && (tc->state == TCP_STATE_LISTEN
2250 || tc->c_rmt_port == hdr->src_port));
2254 handle = session_lookup_half_open_handle (&tc->connection);
2255 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2256 tc->c_proto, tc->c_is_ip4);
2260 if (tmp->lcl_port == hdr->dst_port
2261 && tmp->rmt_port == hdr->src_port)
2263 TCP_DBG ("half-open is valid!");
2271 * Lookup transport connection
2273 static tcp_connection_t *
2274 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2278 transport_connection_t *tconn;
2279 tcp_connection_t *tc;
2284 ip4 = vlib_buffer_get_current (b);
2285 tcp = ip4_next_header (ip4);
2286 tconn = session_lookup_connection_wt4 (fib_index,
2291 TRANSPORT_PROTO_TCP,
2292 thread_index, &is_filtered);
2293 tc = tcp_get_connection_from_transport (tconn);
2294 ASSERT (tcp_lookup_is_valid (tc, tcp));
2299 ip6 = vlib_buffer_get_current (b);
2300 tcp = ip6_next_header (ip6);
2301 tconn = session_lookup_connection_wt6 (fib_index,
2306 TRANSPORT_PROTO_TCP,
2307 thread_index, &is_filtered);
2308 tc = tcp_get_connection_from_transport (tconn);
2309 ASSERT (tcp_lookup_is_valid (tc, tcp));
2315 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2316 vlib_frame_t * from_frame, int is_ip4)
2318 tcp_main_t *tm = vnet_get_tcp_main ();
2319 u32 n_left_from, *from, *first_buffer, errors = 0;
2320 u32 my_thread_index = vm->thread_index;
2321 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2323 from = first_buffer = vlib_frame_vector_args (from_frame);
2324 n_left_from = from_frame->n_vectors;
2326 while (n_left_from > 0)
2328 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2329 tcp_connection_t *tc0, *new_tc0;
2330 tcp_header_t *tcp0 = 0;
2338 b0 = vlib_get_buffer (vm, bi0);
2340 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2341 if (PREDICT_FALSE (tc0 == 0))
2343 error0 = TCP_ERROR_INVALID_CONNECTION;
2347 /* Half-open completed recently but the connection was't removed
2348 * yet by the owning thread */
2349 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2351 /* Make sure the connection actually exists */
2352 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2353 my_thread_index, is_ip4));
2357 ack0 = vnet_buffer (b0)->tcp.ack_number;
2358 seq0 = vnet_buffer (b0)->tcp.seq_number;
2359 tcp0 = tcp_buffer_hdr (b0);
2361 /* Crude check to see if the connection handle does not match
2362 * the packet. Probably connection just switched to established */
2363 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2364 || tcp0->src_port != tc0->c_rmt_port))
2366 error0 = TCP_ERROR_INVALID_CONNECTION;
2370 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2371 && !tcp_syn (tcp0)))
2373 error0 = TCP_ERROR_SEGMENT_INVALID;
2377 /* SYNs, FINs and data consume sequence numbers */
2378 vnet_buffer (b0)->tcp.seq_end =
2379 seq0 + tcp_is_syn (tcp0) + tcp_is_fin (tcp0) +
2380 vnet_buffer (b0)->tcp.data_len;
2383 * 1. check the ACK bit
2387 * If the ACK bit is set
2388 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2389 * the RST bit is set, if so drop the segment and return)
2390 * <SEQ=SEG.ACK><CTL=RST>
2391 * and discard the segment. Return.
2392 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2396 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2398 if (!tcp_rst (tcp0))
2399 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2400 error0 = TCP_ERROR_RCV_WND;
2404 /* Make sure ACK is valid */
2405 if (seq_gt (tc0->snd_una, ack0))
2407 error0 = TCP_ERROR_ACK_INVALID;
2413 * 2. check the RST bit
2418 /* If ACK is acceptable, signal client that peer is not
2419 * willing to accept connection and drop connection*/
2421 tcp_connection_reset (tc0);
2422 error0 = TCP_ERROR_RST_RCVD;
2427 * 3. check the security and precedence (skipped)
2431 * 4. check the SYN bit
2434 /* No SYN flag. Drop. */
2435 if (!tcp_syn (tcp0))
2437 clib_warning ("not synack");
2438 error0 = TCP_ERROR_SEGMENT_INVALID;
2443 if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1))
2445 clib_warning ("options parse fail");
2446 error0 = TCP_ERROR_OPTIONS;
2450 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2451 * current thread pool. */
2452 pool_get (tm->connections[my_thread_index], new_tc0);
2453 clib_memcpy_fast (new_tc0, tc0, sizeof (*new_tc0));
2454 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2455 new_tc0->c_thread_index = my_thread_index;
2456 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2457 new_tc0->irs = seq0;
2458 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
2459 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2460 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2462 /* If this is not the owning thread, wait for syn retransmit to
2463 * expire and cleanup then */
2464 if (tcp_half_open_connection_cleanup (tc0))
2465 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2467 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2469 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2470 new_tc0->tsval_recent_age = tcp_time_now ();
2473 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2474 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2476 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2477 << new_tc0->snd_wscale;
2478 new_tc0->snd_wl1 = seq0;
2479 new_tc0->snd_wl2 = ack0;
2481 tcp_connection_init_vars (new_tc0);
2483 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2484 if (PREDICT_TRUE (tcp_ack (tcp0)))
2486 /* Our SYN is ACKed: we have iss < ack = snd_una */
2488 /* TODO Dequeue acknowledged segments if we support Fast Open */
2489 new_tc0->snd_una = ack0;
2490 new_tc0->state = TCP_STATE_ESTABLISHED;
2492 /* Make sure las is initialized for the wnd computation */
2493 new_tc0->rcv_las = new_tc0->rcv_nxt;
2495 /* Notify app that we have connection. If session layer can't
2496 * allocate session send reset */
2497 if (session_stream_connect_notify (&new_tc0->connection, 0))
2499 clib_warning ("connect notify fail");
2500 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2501 tcp_connection_cleanup (new_tc0);
2505 new_tc0->tx_fifo_size =
2506 transport_tx_fifo_size (&new_tc0->connection);
2507 /* Update rtt with the syn-ack sample */
2508 tcp_estimate_initial_rtt (new_tc0);
2509 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2510 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2512 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2515 new_tc0->state = TCP_STATE_SYN_RCVD;
2517 /* Notify app that we have connection */
2518 if (session_stream_connect_notify (&new_tc0->connection, 0))
2520 tcp_connection_cleanup (new_tc0);
2521 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2522 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2526 new_tc0->tx_fifo_size =
2527 transport_tx_fifo_size (&new_tc0->connection);
2528 new_tc0->rtt_ts = 0;
2529 tcp_init_snd_vars (new_tc0);
2530 tcp_send_synack (new_tc0);
2531 error0 = TCP_ERROR_SYNS_RCVD;
2535 /* Read data, if any */
2536 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2538 clib_warning ("rcvd data in syn-sent");
2539 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2540 if (error0 == TCP_ERROR_ACK_OK)
2541 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2545 tcp_program_ack (wrk, new_tc0);
2550 tcp_inc_counter (syn_sent, error0, 1);
2551 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2553 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2554 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2555 clib_memcpy_fast (&t0->tcp_connection, tc0,
2556 sizeof (t0->tcp_connection));
2560 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2562 tcp_inc_counter (syn_sent, TCP_ERROR_EVENT_FIFO_FULL, errors);
2563 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2565 return from_frame->n_vectors;
2569 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2570 vlib_frame_t * from_frame)
2572 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2576 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2577 vlib_frame_t * from_frame)
2579 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2583 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2585 .function = tcp4_syn_sent,
2586 .name = "tcp4-syn-sent",
2587 /* Takes a vector of packets. */
2588 .vector_size = sizeof (u32),
2589 .n_errors = TCP_N_ERROR,
2590 .error_strings = tcp_error_strings,
2591 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2594 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2595 foreach_tcp_state_next
2598 .format_trace = format_tcp_rx_trace_short,
2602 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2605 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2607 .function = tcp6_syn_sent_rcv,
2608 .name = "tcp6-syn-sent",
2609 /* Takes a vector of packets. */
2610 .vector_size = sizeof (u32),
2611 .n_errors = TCP_N_ERROR,
2612 .error_strings = tcp_error_strings,
2613 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2616 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2617 foreach_tcp_state_next
2620 .format_trace = format_tcp_rx_trace_short,
2624 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2626 vlib_node_registration_t tcp4_rcv_process_node;
2627 vlib_node_registration_t tcp6_rcv_process_node;
2630 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2631 * as per RFC793 p. 64
2634 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2635 vlib_frame_t * from_frame, int is_ip4)
2637 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2638 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2639 u32 n_left_from, *from;
2641 from = first_buffer = vlib_frame_vector_args (from_frame);
2642 n_left_from = from_frame->n_vectors;
2644 while (n_left_from > 0)
2646 u32 bi0, error0 = TCP_ERROR_NONE;
2647 tcp_header_t *tcp0 = 0;
2648 tcp_connection_t *tc0;
2656 b0 = vlib_get_buffer (vm, bi0);
2657 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2659 if (PREDICT_FALSE (tc0 == 0))
2661 error0 = TCP_ERROR_INVALID_CONNECTION;
2665 tcp0 = tcp_buffer_hdr (b0);
2666 is_fin0 = tcp_is_fin (tcp0);
2668 /* SYNs, FINs and data consume sequence numbers */
2669 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2670 + tcp_is_syn (tcp0) + is_fin0 + vnet_buffer (b0)->tcp.data_len;
2674 tcp_connection_t *tmp;
2675 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2677 if (tmp->state != tc0->state)
2679 clib_warning ("state changed");
2685 * Special treatment for CLOSED
2687 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2689 error0 = TCP_ERROR_CONNECTION_CLOSED;
2694 * For all other states (except LISTEN)
2697 /* 1-4: check SEQ, RST, SYN */
2698 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2701 /* 5: check the ACK field */
2704 case TCP_STATE_SYN_RCVD:
2706 * If the segment acknowledgment is not acceptable, form a
2708 * <SEQ=SEG.ACK><CTL=RST>
2711 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2713 TCP_DBG ("connection not accepted");
2714 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2715 error0 = TCP_ERROR_ACK_INVALID;
2719 /* Update rtt and rto */
2720 tcp_estimate_initial_rtt (tc0);
2722 /* Switch state to ESTABLISHED */
2723 tc0->state = TCP_STATE_ESTABLISHED;
2724 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2726 /* Initialize session variables */
2727 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2728 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2729 << tc0->rcv_opts.wscale;
2730 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2731 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2733 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2734 tcp_retransmit_timer_reset (tc0);
2735 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2736 stream_session_accept_notify (&tc0->connection);
2737 error0 = TCP_ERROR_ACK_OK;
2739 case TCP_STATE_ESTABLISHED:
2740 /* We can get packets in established state here because they
2741 * were enqueued before state change */
2742 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2746 case TCP_STATE_FIN_WAIT_1:
2747 /* In addition to the processing for the ESTABLISHED state, if
2748 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2749 * continue processing in that state. */
2750 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2753 /* Still have to send the FIN */
2754 if (tc0->flags & TCP_CONN_FINPNDG)
2756 /* TX fifo finally drained */
2757 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2760 /* If FIN is ACKed */
2761 else if (tc0->snd_una == tc0->snd_una_max)
2763 tc0->state = TCP_STATE_FIN_WAIT_2;
2764 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2766 /* Stop all retransmit timers because we have nothing more
2767 * to send. Enable waitclose though because we're willing to
2768 * wait for peer's FIN but not indefinitely. */
2769 tcp_connection_timers_reset (tc0);
2770 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2772 /* Don't try to deq the FIN acked */
2773 if (tc0->burst_acked > 1)
2774 stream_session_dequeue_drop (&tc0->connection,
2775 tc0->burst_acked - 1);
2776 tc0->burst_acked = 0;
2779 case TCP_STATE_FIN_WAIT_2:
2780 /* In addition to the processing for the ESTABLISHED state, if
2781 * the retransmission queue is empty, the user's CLOSE can be
2782 * acknowledged ("ok") but do not delete the TCB. */
2783 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2785 tc0->burst_acked = 0;
2787 case TCP_STATE_CLOSE_WAIT:
2788 /* Do the same processing as for the ESTABLISHED state. */
2789 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2792 if (tc0->flags & TCP_CONN_FINPNDG)
2794 /* TX fifo finally drained */
2795 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2798 tcp_connection_timers_reset (tc0);
2799 tc0->state = TCP_STATE_LAST_ACK;
2800 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2804 case TCP_STATE_CLOSING:
2805 /* In addition to the processing for the ESTABLISHED state, if
2806 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2807 * otherwise ignore the segment. */
2808 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2811 tc0->state = TCP_STATE_TIME_WAIT;
2812 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2813 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2817 case TCP_STATE_LAST_ACK:
2818 /* The only thing that [should] arrive in this state is an
2819 * acknowledgment of our FIN. If our FIN is now acknowledged,
2820 * delete the TCB, enter the CLOSED state, and return. */
2822 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2824 error0 = TCP_ERROR_ACK_INVALID;
2827 error0 = TCP_ERROR_ACK_OK;
2828 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2829 /* Apparently our ACK for the peer's FIN was lost */
2830 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2836 tc0->state = TCP_STATE_CLOSED;
2837 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2839 /* Don't free the connection from the data path since
2840 * we can't ensure that we have no packets already enqueued
2841 * to output. Rely instead on the waitclose timer */
2842 tcp_connection_timers_reset (tc0);
2843 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, 1);
2848 case TCP_STATE_TIME_WAIT:
2849 /* The only thing that can arrive in this state is a
2850 * retransmission of the remote FIN. Acknowledge it, and restart
2851 * the 2 MSL timeout. */
2853 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2856 tcp_program_ack (wrk, tc0);
2857 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2865 /* 6: check the URG bit TODO */
2867 /* 7: process the segment text */
2870 case TCP_STATE_ESTABLISHED:
2871 case TCP_STATE_FIN_WAIT_1:
2872 case TCP_STATE_FIN_WAIT_2:
2873 if (vnet_buffer (b0)->tcp.data_len)
2874 error0 = tcp_segment_rcv (wrk, tc0, b0);
2878 case TCP_STATE_CLOSE_WAIT:
2879 case TCP_STATE_CLOSING:
2880 case TCP_STATE_LAST_ACK:
2881 case TCP_STATE_TIME_WAIT:
2882 /* This should not occur, since a FIN has been received from the
2883 * remote side. Ignore the segment text. */
2887 /* 8: check the FIN bit */
2893 case TCP_STATE_ESTABLISHED:
2894 case TCP_STATE_SYN_RCVD:
2895 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2896 tcp_connection_timers_reset (tc0);
2898 stream_session_disconnect_notify (&tc0->connection);
2899 tc0->state = TCP_STATE_CLOSE_WAIT;
2900 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2902 case TCP_STATE_CLOSE_WAIT:
2903 case TCP_STATE_CLOSING:
2904 case TCP_STATE_LAST_ACK:
2907 case TCP_STATE_FIN_WAIT_1:
2908 tc0->state = TCP_STATE_CLOSING;
2909 tcp_program_ack (wrk, tc0);
2910 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2911 /* Wait for ACK but not forever */
2912 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2914 case TCP_STATE_FIN_WAIT_2:
2915 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2916 tc0->state = TCP_STATE_TIME_WAIT;
2917 tcp_connection_timers_reset (tc0);
2918 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2919 tcp_program_ack (wrk, tc0);
2920 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2922 case TCP_STATE_TIME_WAIT:
2923 /* Remain in the TIME-WAIT state. Restart the time-wait
2926 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2929 error0 = TCP_ERROR_FIN_RCVD;
2930 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2934 tcp_inc_counter (rcv_process, error0, 1);
2935 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2937 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2938 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2942 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2944 tcp_inc_counter (rcv_process, TCP_ERROR_EVENT_FIFO_FULL, errors);
2945 tcp_handle_postponed_dequeues (wrk);
2946 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2948 return from_frame->n_vectors;
2952 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2953 vlib_frame_t * from_frame)
2955 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2959 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2960 vlib_frame_t * from_frame)
2962 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2966 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2968 .function = tcp4_rcv_process,
2969 .name = "tcp4-rcv-process",
2970 /* Takes a vector of packets. */
2971 .vector_size = sizeof (u32),
2972 .n_errors = TCP_N_ERROR,
2973 .error_strings = tcp_error_strings,
2974 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2977 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2978 foreach_tcp_state_next
2981 .format_trace = format_tcp_rx_trace_short,
2985 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2988 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2990 .function = tcp6_rcv_process,
2991 .name = "tcp6-rcv-process",
2992 /* Takes a vector of packets. */
2993 .vector_size = sizeof (u32),
2994 .n_errors = TCP_N_ERROR,
2995 .error_strings = tcp_error_strings,
2996 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2999 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3000 foreach_tcp_state_next
3003 .format_trace = format_tcp_rx_trace_short,
3007 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
3009 vlib_node_registration_t tcp4_listen_node;
3010 vlib_node_registration_t tcp6_listen_node;
3013 * LISTEN state processing as per RFC 793 p. 65
3016 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3017 vlib_frame_t * from_frame, int is_ip4)
3019 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3020 u32 my_thread_index = vm->thread_index;
3022 from = first_buffer = vlib_frame_vector_args (from_frame);
3023 n_left_from = from_frame->n_vectors;
3025 while (n_left_from > 0)
3030 tcp_header_t *th0 = 0;
3031 tcp_connection_t *lc0;
3034 tcp_connection_t *child0;
3035 u32 error0 = TCP_ERROR_NONE;
3041 b0 = vlib_get_buffer (vm, bi0);
3042 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3046 ip40 = vlib_buffer_get_current (b0);
3047 th0 = ip4_next_header (ip40);
3051 ip60 = vlib_buffer_get_current (b0);
3052 th0 = ip6_next_header (ip60);
3055 /* Create child session. For syn-flood protection use filter */
3057 /* 1. first check for an RST: handled in dispatch */
3058 /* if (tcp_rst (th0))
3062 /* 2. second check for an ACK: handled in dispatch */
3063 /* if (tcp_ack (th0))
3065 tcp_send_reset (b0, is_ip4);
3070 /* 3. check for a SYN (did that already) */
3072 /* Make sure connection wasn't just created */
3073 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3075 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3077 error0 = TCP_ERROR_CREATE_EXISTS;
3081 /* Create child session and send SYN-ACK */
3082 child0 = tcp_connection_new (my_thread_index);
3083 child0->c_lcl_port = th0->dst_port;
3084 child0->c_rmt_port = th0->src_port;
3085 child0->c_is_ip4 = is_ip4;
3086 child0->state = TCP_STATE_SYN_RCVD;
3087 child0->c_fib_index = lc0->c_fib_index;
3091 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3092 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3096 clib_memcpy_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3097 sizeof (ip6_address_t));
3098 clib_memcpy_fast (&child0->c_rmt_ip6, &ip60->src_address,
3099 sizeof (ip6_address_t));
3102 if (tcp_options_parse (th0, &child0->rcv_opts, 1))
3104 clib_warning ("options parse fail");
3108 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3109 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3110 child0->rcv_las = child0->rcv_nxt;
3111 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3113 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3114 * segments are used to initialize PAWS. */
3115 if (tcp_opts_tstamp (&child0->rcv_opts))
3117 child0->tsval_recent = child0->rcv_opts.tsval;
3118 child0->tsval_recent_age = tcp_time_now ();
3121 if (tcp_opts_wscale (&child0->rcv_opts))
3122 child0->snd_wscale = child0->rcv_opts.wscale;
3124 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3125 << child0->snd_wscale;
3126 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3127 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3129 tcp_connection_init_vars (child0);
3130 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
3132 if (stream_session_accept (&child0->connection, lc0->c_s_index,
3135 clib_warning ("session accept fail");
3136 tcp_connection_cleanup (child0);
3137 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3141 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3142 tcp_send_synack (child0);
3143 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
3147 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3149 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3150 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3151 clib_memcpy_fast (&t0->tcp_connection, lc0,
3152 sizeof (t0->tcp_connection));
3155 n_syns += (error0 == TCP_ERROR_NONE);
3158 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3159 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3161 return from_frame->n_vectors;
3165 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3166 vlib_frame_t * from_frame)
3168 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3172 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3173 vlib_frame_t * from_frame)
3175 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3179 VLIB_REGISTER_NODE (tcp4_listen_node) =
3181 .function = tcp4_listen,
3182 .name = "tcp4-listen",
3183 /* Takes a vector of packets. */
3184 .vector_size = sizeof (u32),
3185 .n_errors = TCP_N_ERROR,
3186 .error_strings = tcp_error_strings,
3187 .n_next_nodes = TCP_LISTEN_N_NEXT,
3190 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3191 foreach_tcp_state_next
3194 .format_trace = format_tcp_rx_trace_short,
3198 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
3201 VLIB_REGISTER_NODE (tcp6_listen_node) =
3203 .function = tcp6_listen,
3204 .name = "tcp6-listen",
3205 /* Takes a vector of packets. */
3206 .vector_size = sizeof (u32),
3207 .n_errors = TCP_N_ERROR,
3208 .error_strings = tcp_error_strings,
3209 .n_next_nodes = TCP_LISTEN_N_NEXT,
3212 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3213 foreach_tcp_state_next
3216 .format_trace = format_tcp_rx_trace_short,
3220 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
3222 vlib_node_registration_t tcp4_input_node;
3223 vlib_node_registration_t tcp6_input_node;
3225 typedef enum _tcp_input_next
3227 TCP_INPUT_NEXT_DROP,
3228 TCP_INPUT_NEXT_LISTEN,
3229 TCP_INPUT_NEXT_RCV_PROCESS,
3230 TCP_INPUT_NEXT_SYN_SENT,
3231 TCP_INPUT_NEXT_ESTABLISHED,
3232 TCP_INPUT_NEXT_RESET,
3233 TCP_INPUT_NEXT_PUNT,
3237 #define foreach_tcp4_input_next \
3238 _ (DROP, "ip4-drop") \
3239 _ (LISTEN, "tcp4-listen") \
3240 _ (RCV_PROCESS, "tcp4-rcv-process") \
3241 _ (SYN_SENT, "tcp4-syn-sent") \
3242 _ (ESTABLISHED, "tcp4-established") \
3243 _ (RESET, "tcp4-reset") \
3244 _ (PUNT, "ip4-punt")
3246 #define foreach_tcp6_input_next \
3247 _ (DROP, "ip6-drop") \
3248 _ (LISTEN, "tcp6-listen") \
3249 _ (RCV_PROCESS, "tcp6-rcv-process") \
3250 _ (SYN_SENT, "tcp6-syn-sent") \
3251 _ (ESTABLISHED, "tcp6-established") \
3252 _ (RESET, "tcp6-reset") \
3253 _ (PUNT, "ip6-punt")
3255 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3258 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3259 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3261 tcp_connection_t *tc;
3266 for (i = 0; i < n_bufs; i++)
3268 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3270 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3271 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3273 tcp = vlib_buffer_get_current (bs[i]);
3274 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3280 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3282 if (*error == TCP_ERROR_FILTERED)
3284 *next = TCP_INPUT_NEXT_DROP;
3286 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3288 *next = TCP_INPUT_NEXT_PUNT;
3289 *error = TCP_ERROR_PUNT;
3293 *next = TCP_INPUT_NEXT_RESET;
3294 *error = TCP_ERROR_NO_LISTENER;
3298 static inline tcp_connection_t *
3299 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3302 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3303 int n_advance_bytes, n_data_bytes;
3304 transport_connection_t *tc;
3310 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3311 int ip_hdr_bytes = ip4_header_bytes (ip4);
3312 if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
3314 *error = TCP_ERROR_LENGTH;
3317 tcp = ip4_next_header (ip4);
3318 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3319 n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
3320 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3322 /* Length check. Checksum computed by ipx_local no need to compute again */
3323 if (PREDICT_FALSE (n_data_bytes < 0))
3325 *error = TCP_ERROR_LENGTH;
3329 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3330 &ip4->src_address, tcp->dst_port,
3331 tcp->src_port, TRANSPORT_PROTO_TCP,
3332 thread_index, &is_filtered);
3336 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3337 if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
3339 *error = TCP_ERROR_LENGTH;
3342 tcp = ip6_next_header (ip6);
3343 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3344 n_advance_bytes = tcp_header_bytes (tcp);
3345 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3347 n_advance_bytes += sizeof (ip6[0]);
3349 if (PREDICT_FALSE (n_data_bytes < 0))
3351 *error = TCP_ERROR_LENGTH;
3355 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3356 &ip6->src_address, tcp->dst_port,
3357 tcp->src_port, TRANSPORT_PROTO_TCP,
3358 thread_index, &is_filtered);
3361 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3362 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3363 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3364 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3365 vnet_buffer (b)->tcp.flags = 0;
3367 *error = is_filtered ? TCP_ERROR_FILTERED : *error;
3369 return tcp_get_connection_from_transport (tc);
3373 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3374 vlib_buffer_t * b, u16 * next, u32 * error)
3379 tcp = tcp_buffer_hdr (b);
3380 flags = tcp->flags & filter_flags;
3381 *next = tm->dispatch_table[tc->state][flags].next;
3382 *error = tm->dispatch_table[tc->state][flags].error;
3384 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3385 || *next == TCP_INPUT_NEXT_RESET))
3387 /* Overload tcp flags to store state */
3388 tcp_state_t state = tc->state;
3389 vnet_buffer (b)->tcp.flags = tc->state;
3391 if (*error == TCP_ERROR_DISPATCH)
3392 clib_warning ("disp error state %U flags %U", format_tcp_state,
3393 state, format_tcp_flags, (int) flags);
3398 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3399 vlib_frame_t * frame, int is_ip4)
3401 u32 n_left_from, *from, thread_index = vm->thread_index;
3402 tcp_main_t *tm = vnet_get_tcp_main ();
3403 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3404 u16 nexts[VLIB_FRAME_SIZE], *next;
3406 tcp_set_time_now (tcp_get_worker (thread_index));
3408 from = vlib_frame_vector_args (frame);
3409 n_left_from = frame->n_vectors;
3410 vlib_get_buffers (vm, from, bufs, n_left_from);
3415 while (n_left_from >= 4)
3417 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3418 tcp_connection_t *tc0, *tc1;
3421 vlib_prefetch_buffer_header (b[2], STORE);
3422 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3424 vlib_prefetch_buffer_header (b[3], STORE);
3425 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3428 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3430 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3431 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4);
3433 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3435 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3436 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3438 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3439 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3441 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3442 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3446 if (PREDICT_TRUE (tc0 != 0))
3448 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3449 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3450 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3453 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3455 if (PREDICT_TRUE (tc1 != 0))
3457 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3458 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3459 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3462 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3469 while (n_left_from > 0)
3471 tcp_connection_t *tc0;
3472 u32 error0 = TCP_ERROR_NO_LISTENER;
3474 if (n_left_from > 1)
3476 vlib_prefetch_buffer_header (b[1], STORE);
3477 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3480 next[0] = TCP_INPUT_NEXT_DROP;
3481 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3482 if (PREDICT_TRUE (tc0 != 0))
3484 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3485 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3486 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3489 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3496 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3497 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3499 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3500 return frame->n_vectors;
3504 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3505 vlib_frame_t * from_frame)
3507 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3511 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3512 vlib_frame_t * from_frame)
3514 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3518 VLIB_REGISTER_NODE (tcp4_input_node) =
3520 .function = tcp4_input,
3521 .name = "tcp4-input",
3522 /* Takes a vector of packets. */
3523 .vector_size = sizeof (u32),
3524 .n_errors = TCP_N_ERROR,
3525 .error_strings = tcp_error_strings,
3526 .n_next_nodes = TCP_INPUT_N_NEXT,
3529 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3530 foreach_tcp4_input_next
3533 .format_buffer = format_tcp_header,
3534 .format_trace = format_tcp_rx_trace,
3538 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3541 VLIB_REGISTER_NODE (tcp6_input_node) =
3543 .function = tcp6_input,
3544 .name = "tcp6-input",
3545 /* Takes a vector of packets. */
3546 .vector_size = sizeof (u32),
3547 .n_errors = TCP_N_ERROR,
3548 .error_strings = tcp_error_strings,
3549 .n_next_nodes = TCP_INPUT_N_NEXT,
3552 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3553 foreach_tcp6_input_next
3556 .format_buffer = format_tcp_header,
3557 .format_trace = format_tcp_rx_trace,
3561 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3564 tcp_dispatch_table_init (tcp_main_t * tm)
3567 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3568 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3570 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3571 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3574 #define _(t,f,n,e) \
3576 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3577 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3580 /* SYNs for new connections -> tcp-listen. */
3581 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3582 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3583 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_RST_RCVD);
3584 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3586 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3587 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3588 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3589 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3591 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3592 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3594 /* SYN-ACK for a SYN */
3595 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3597 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3598 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3599 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3601 /* ACK for for established connection -> tcp-established. */
3602 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3603 /* FIN for for established connection -> tcp-established. */
3604 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3605 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3607 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3608 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3610 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3611 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3613 /* ACK or FIN-ACK to our FIN */
3614 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3615 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3617 /* FIN in reply to our FIN from the other side */
3618 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3619 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3620 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3621 /* FIN confirming that the peer (app) has closed */
3622 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3623 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3624 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3626 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3627 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3629 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3630 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3631 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3633 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3634 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3635 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3636 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3638 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3639 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3640 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3641 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3642 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3643 TCP_ERROR_CONNECTION_CLOSED);
3647 static clib_error_t *
3648 tcp_input_init (vlib_main_t * vm)
3650 clib_error_t *error = 0;
3651 tcp_main_t *tm = vnet_get_tcp_main ();
3653 if ((error = vlib_call_init_function (vm, tcp_init)))
3656 /* Initialize dispatch table. */
3657 tcp_dispatch_table_init (tm);
3662 VLIB_INIT_FUNCTION (tcp_input_init);
3665 * fd.io coding-style-patch-verification: ON
3668 * eval: (c-set-style "gnu")