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)
186 to->wscale = TCP_MAX_WND_SCALE;
189 case TCP_OPTION_TIMESTAMP:
191 to->flags |= TCP_OPTS_FLAG_TSTAMP;
192 if ((to->flags & TCP_OPTS_FLAG_TSTAMP)
193 && opt_len == TCP_OPTION_LEN_TIMESTAMP)
195 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
196 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
199 case TCP_OPTION_SACK_PERMITTED:
202 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
203 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
205 case TCP_OPTION_SACK_BLOCK:
206 /* If SACK permitted was not advertised or a SYN, break */
207 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
210 /* If too short or not correctly formatted, break */
211 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
214 to->flags |= TCP_OPTS_FLAG_SACK;
215 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
216 vec_reset_length (to->sacks);
217 for (j = 0; j < to->n_sack_blocks; j++)
219 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 8 * j));
220 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 8 * j));
221 vec_add1 (to->sacks, b);
225 /* Nothing to see here */
233 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
234 * timestamp to echo and it's less than tsval_recent, drop segment
235 * but still send an ACK in order to retain TCP's mechanism for detecting
236 * and recovering from half-open connections
238 * Or at least that's what the theory says. It seems that this might not work
239 * very well with packet reordering and fast retransmit. XXX
242 tcp_segment_check_paws (tcp_connection_t * tc)
244 return tcp_opts_tstamp (&tc->rcv_opts)
245 && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent);
249 * Update tsval recent
252 tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
255 * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
256 * of an incoming segment:
257 * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
258 * then the TSval from the segment is copied to TS.Recent;
259 * otherwise, the TSval is ignored.
261 if (tcp_opts_tstamp (&tc->rcv_opts) && seq_leq (seq, tc->rcv_las)
262 && seq_leq (tc->rcv_las, seq_end))
264 ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval));
265 tc->tsval_recent = tc->rcv_opts.tsval;
266 tc->tsval_recent_age = tcp_time_now_w_thread (tc->c_thread_index);
271 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
273 * It first verifies if segment has a wrapped sequence number (PAWS) and then
274 * does the processing associated to the first four steps (ignoring security
275 * and precedence): sequence number, rst bit and syn bit checks.
277 * @return 0 if segments passes validation.
280 tcp_segment_validate (tcp_worker_ctx_t * wrk, tcp_connection_t * tc0,
281 vlib_buffer_t * b0, tcp_header_t * th0, u32 * error0)
283 /* We could get a burst of RSTs interleaved with acks */
284 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
286 tcp_send_reset (tc0);
287 *error0 = TCP_ERROR_CONNECTION_CLOSED;
291 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
293 *error0 = TCP_ERROR_SEGMENT_INVALID;
297 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts, 0)))
299 *error0 = TCP_ERROR_OPTIONS;
303 if (PREDICT_FALSE (tcp_segment_check_paws (tc0)))
305 *error0 = TCP_ERROR_PAWS;
306 TCP_EVT_DBG (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
307 vnet_buffer (b0)->tcp.seq_end);
309 /* If it just so happens that a segment updates tsval_recent for a
310 * segment over 24 days old, invalidate tsval_recent. */
311 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
312 tcp_time_now_w_thread (tc0->c_thread_index)))
314 tc0->tsval_recent = tc0->rcv_opts.tsval;
315 clib_warning ("paws failed: 24-day old segment");
317 /* Drop after ack if not rst. Resets can fail paws check as per
318 * RFC 7323 sec. 5.2: When an <RST> segment is received, it MUST NOT
319 * be subjected to the PAWS check by verifying an acceptable value in
321 else if (!tcp_rst (th0))
323 tcp_program_ack (wrk, tc0);
324 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
329 /* 1st: check sequence number */
330 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
331 vnet_buffer (b0)->tcp.seq_end))
333 *error0 = TCP_ERROR_RCV_WND;
334 /* If our window is 0 and the packet is in sequence, let it pass
335 * through for ack processing. It should be dropped later. */
336 if (!(tc0->rcv_wnd == 0
337 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number))
339 /* If not RST, send dup ack */
342 tcp_program_dupack (wrk, tc0);
343 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
349 /* 2nd: check the RST bit */
350 if (PREDICT_FALSE (tcp_rst (th0)))
352 tcp_connection_reset (tc0);
353 *error0 = TCP_ERROR_RST_RCVD;
357 /* 3rd: check security and precedence (skip) */
359 /* 4th: check the SYN bit */
360 if (PREDICT_FALSE (tcp_syn (th0)))
362 /* TODO implement RFC 5961 */
363 if (tc0->state == TCP_STATE_SYN_RCVD)
365 tcp_options_parse (th0, &tc0->rcv_opts, 1);
366 tcp_send_synack (tc0);
367 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0, 0);
371 tcp_program_ack (wrk, tc0);
372 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, tc0);
377 /* If segment in window, save timestamp */
378 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
379 vnet_buffer (b0)->tcp.seq_end);
387 tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0)
389 /* SND.UNA =< SEG.ACK =< SND.NXT */
390 return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number)
391 && seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt));
395 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
397 * Note that although the original article, srtt and rttvar are scaled
398 * to minimize round-off errors, here we don't. Instead, we rely on
399 * better precision time measurements.
401 * TODO support us rtt resolution
404 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
410 err = mrtt - tc->srtt;
412 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
413 * The increase should be bound */
414 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
415 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
416 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
420 /* First measurement. */
422 tc->rttvar = mrtt >> 1;
427 tcp_update_rto (tcp_connection_t * tc)
429 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
430 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
434 * Update RTT estimate and RTO timer
436 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
437 * timing. Middle boxes are known to fiddle with TCP options so we
438 * should give higher priority to ACK timing.
440 * This should be called only if previously sent bytes have been acked.
442 * return 1 if valid rtt 0 otherwise
445 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
449 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
450 * RTT because they're ambiguous. */
451 if (tcp_in_cong_recovery (tc) || tc->sack_sb.sacked_bytes)
453 if (tcp_in_recovery (tc))
458 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
460 f64 sample = tcp_time_now_us (tc->c_thread_index) - tc->rtt_ts;
461 tc->mrtt_us = tc->mrtt_us + (sample - tc->mrtt_us) * 0.125;
462 mrtt = clib_max ((u32) (sample * THZ), 1);
463 /* Allow measuring of a new RTT */
466 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
467 * snd_una, i.e., the left side of the send window:
468 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
469 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
471 u32 now = tcp_time_now_w_thread (tc->c_thread_index);
472 mrtt = clib_max (now - tc->rcv_opts.tsecr, 1);
475 /* Ignore dubious measurements */
476 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
479 tcp_estimate_rtt (tc, mrtt);
483 /* If we got here something must've been ACKed so make sure boff is 0,
484 * even if mrtt is not valid since we update the rto lower */
492 tcp_estimate_initial_rtt (tcp_connection_t * tc)
494 u8 thread_index = vlib_num_workers ()? 1 : 0;
499 tc->mrtt_us = tcp_time_now_us (thread_index) - tc->rtt_ts;
500 mrtt = clib_max ((u32) (tc->mrtt_us * THZ), 1);
505 mrtt = tcp_time_now_w_thread (thread_index) - tc->rcv_opts.tsecr;
506 mrtt = clib_max (mrtt, 1);
507 tc->mrtt_us = (f64) mrtt *TCP_TICK;
510 if (mrtt > 0 && mrtt < TCP_RTT_MAX)
511 tcp_estimate_rtt (tc, mrtt);
516 * Dequeue bytes for connections that have received acks in last burst
519 tcp_handle_postponed_dequeues (tcp_worker_ctx_t * wrk)
521 u32 thread_index = wrk->vm->thread_index;
522 u32 *pending_deq_acked;
523 tcp_connection_t *tc;
526 if (!vec_len (wrk->pending_deq_acked))
529 pending_deq_acked = wrk->pending_deq_acked;
530 for (i = 0; i < vec_len (pending_deq_acked); i++)
532 tc = tcp_connection_get (pending_deq_acked[i], thread_index);
533 tc->flags &= ~TCP_CONN_DEQ_PENDING;
535 if (PREDICT_FALSE (!tc->burst_acked))
538 /* Dequeue the newly ACKed bytes */
539 stream_session_dequeue_drop (&tc->connection, tc->burst_acked);
541 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
543 if (PREDICT_FALSE (tc->flags & TCP_CONN_PSH_PENDING))
545 if (seq_leq (tc->psh_seq, tc->snd_una))
546 tc->flags &= ~TCP_CONN_PSH_PENDING;
549 /* If everything has been acked, stop retransmit timer
550 * otherwise update. */
551 tcp_retransmit_timer_update (tc);
553 /* If not congested, update pacer based on our new
555 if (!tcp_in_fastrecovery (tc))
556 tcp_connection_tx_pacer_update (tc);
558 _vec_len (wrk->pending_deq_acked) = 0;
562 tcp_program_dequeue (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
564 if (!(tc->flags & TCP_CONN_DEQ_PENDING))
566 vec_add1 (wrk->pending_deq_acked, tc->c_c_index);
567 tc->flags |= TCP_CONN_DEQ_PENDING;
569 tc->burst_acked += tc->bytes_acked + tc->sack_sb.snd_una_adv;
573 * Check if duplicate ack as per RFC5681 Sec. 2
576 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
579 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
580 && seq_gt (tc->snd_una_max, tc->snd_una)
581 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
582 && (prev_snd_wnd == tc->snd_wnd));
586 * Checks if ack is a congestion control event.
589 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
590 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
592 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
593 * defined to be 'duplicate' */
594 *is_dack = tc->sack_sb.last_sacked_bytes
595 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
597 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
601 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
603 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
604 return hole - sb->holes;
608 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
610 return hole->end - hole->start;
613 sack_scoreboard_hole_t *
614 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
616 if (index != TCP_INVALID_SACK_HOLE_INDEX)
617 return pool_elt_at_index (sb->holes, index);
621 sack_scoreboard_hole_t *
622 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
624 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
625 return pool_elt_at_index (sb->holes, hole->next);
629 sack_scoreboard_hole_t *
630 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
632 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
633 return pool_elt_at_index (sb->holes, hole->prev);
637 sack_scoreboard_hole_t *
638 scoreboard_first_hole (sack_scoreboard_t * sb)
640 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
641 return pool_elt_at_index (sb->holes, sb->head);
645 sack_scoreboard_hole_t *
646 scoreboard_last_hole (sack_scoreboard_t * sb)
648 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
649 return pool_elt_at_index (sb->holes, sb->tail);
654 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
656 sack_scoreboard_hole_t *next, *prev;
658 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
660 next = pool_elt_at_index (sb->holes, hole->next);
661 next->prev = hole->prev;
665 sb->tail = hole->prev;
668 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
670 prev = pool_elt_at_index (sb->holes, hole->prev);
671 prev->next = hole->next;
675 sb->head = hole->next;
678 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
679 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
681 /* Poison the entry */
683 clib_memset (hole, 0xfe, sizeof (*hole));
685 pool_put (sb->holes, hole);
688 static sack_scoreboard_hole_t *
689 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
692 sack_scoreboard_hole_t *hole, *next, *prev;
695 pool_get (sb->holes, hole);
696 clib_memset (hole, 0, sizeof (*hole));
700 hole_index = scoreboard_hole_index (sb, hole);
702 prev = scoreboard_get_hole (sb, prev_index);
705 hole->prev = prev_index;
706 hole->next = prev->next;
708 if ((next = scoreboard_next_hole (sb, hole)))
709 next->prev = hole_index;
711 sb->tail = hole_index;
713 prev->next = hole_index;
717 sb->head = hole_index;
718 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
719 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
726 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
728 sack_scoreboard_hole_t *left, *right;
729 u32 bytes = 0, blks = 0;
732 sb->sacked_bytes = 0;
733 left = scoreboard_last_hole (sb);
737 if (seq_gt (sb->high_sacked, left->end))
739 bytes = sb->high_sacked - left->end;
743 while ((right = left)
744 && bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
745 && blks < TCP_DUPACK_THRESHOLD
746 /* left not updated if above conditions fail */
747 && (left = scoreboard_prev_hole (sb, right)))
749 bytes += right->start - left->end;
753 /* left is first lost */
758 sb->lost_bytes += scoreboard_hole_bytes (right);
760 left = scoreboard_prev_hole (sb, right);
762 bytes += right->start - left->end;
764 while ((right = left));
767 sb->sacked_bytes = bytes;
771 * Figure out the next hole to retransmit
773 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
775 sack_scoreboard_hole_t *
776 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
777 sack_scoreboard_hole_t * start,
778 u8 have_unsent, u8 * can_rescue, u8 * snd_limited)
780 sack_scoreboard_hole_t *hole = 0;
782 hole = start ? start : scoreboard_first_hole (sb);
783 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
784 hole = scoreboard_next_hole (sb, hole);
786 /* Nothing, return */
789 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
793 /* Rule (1): if higher than rxt, less than high_sacked and lost */
794 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
796 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
800 /* Rule (2): available unsent data */
803 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
806 /* Rule (3): if hole not lost */
807 else if (seq_lt (hole->start, sb->high_sacked))
810 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
812 /* Rule (4): if hole beyond high_sacked */
815 ASSERT (seq_geq (hole->start, sb->high_sacked));
818 /* HighRxt MUST NOT be updated */
823 if (hole && seq_lt (sb->high_rxt, hole->start))
824 sb->high_rxt = hole->start;
830 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 snd_una)
832 sack_scoreboard_hole_t *hole;
833 hole = scoreboard_first_hole (sb);
836 snd_una = seq_gt (snd_una, hole->start) ? snd_una : hole->start;
837 sb->cur_rxt_hole = sb->head;
839 sb->high_rxt = snd_una;
840 sb->rescue_rxt = snd_una - 1;
844 scoreboard_init (sack_scoreboard_t * sb)
846 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
847 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
848 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
852 scoreboard_clear (sack_scoreboard_t * sb)
854 sack_scoreboard_hole_t *hole;
855 while ((hole = scoreboard_first_hole (sb)))
857 scoreboard_remove_hole (sb, hole);
859 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
860 ASSERT (pool_elts (sb->holes) == 0);
861 sb->sacked_bytes = 0;
862 sb->last_sacked_bytes = 0;
863 sb->last_bytes_delivered = 0;
868 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
872 * Test that scoreboard is sane after recovery
874 * Returns 1 if scoreboard is empty or if first hole beyond
878 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
880 sack_scoreboard_hole_t *hole;
881 hole = scoreboard_first_hole (&tc->sack_sb);
882 return (!hole || (seq_geq (hole->start, tc->snd_una)
883 && seq_lt (hole->end, tc->snd_una_max)));
887 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
889 sack_scoreboard_t *sb = &tc->sack_sb;
890 sack_block_t *blk, tmp;
891 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
892 u32 blk_index = 0, old_sacked_bytes, hole_index;
895 sb->last_sacked_bytes = 0;
896 sb->last_bytes_delivered = 0;
899 if (!tcp_opts_sack (&tc->rcv_opts)
900 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
903 old_sacked_bytes = sb->sacked_bytes;
905 /* Remove invalid blocks */
906 blk = tc->rcv_opts.sacks;
907 while (blk < vec_end (tc->rcv_opts.sacks))
909 if (seq_lt (blk->start, blk->end)
910 && seq_gt (blk->start, tc->snd_una)
911 && seq_gt (blk->start, ack)
912 && seq_lt (blk->start, tc->snd_una_max)
913 && seq_leq (blk->end, tc->snd_una_max))
918 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
921 /* Add block for cumulative ack */
922 if (seq_gt (ack, tc->snd_una))
924 tmp.start = tc->snd_una;
926 vec_add1 (tc->rcv_opts.sacks, tmp);
929 if (vec_len (tc->rcv_opts.sacks) == 0)
932 tcp_scoreboard_trace_add (tc, ack);
934 /* Make sure blocks are ordered */
935 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
936 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
937 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
939 tmp = tc->rcv_opts.sacks[i];
940 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
941 tc->rcv_opts.sacks[j] = tmp;
944 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
946 /* If no holes, insert the first that covers all outstanding bytes */
947 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
948 tc->snd_una, tc->snd_una_max);
949 sb->tail = scoreboard_hole_index (sb, last_hole);
950 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
951 sb->high_sacked = tmp.end;
955 /* If we have holes but snd_una_max is beyond the last hole, update
957 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
958 last_hole = scoreboard_last_hole (sb);
959 if (seq_gt (tc->snd_una_max, last_hole->end))
961 if (seq_geq (last_hole->start, sb->high_sacked))
963 last_hole->end = tc->snd_una_max;
965 /* New hole after high sacked block */
966 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
968 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
972 /* Keep track of max byte sacked for when the last hole
974 if (seq_gt (tmp.end, sb->high_sacked))
975 sb->high_sacked = tmp.end;
978 /* Walk the holes with the SACK blocks */
979 hole = pool_elt_at_index (sb->holes, sb->head);
980 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
982 blk = &tc->rcv_opts.sacks[blk_index];
983 if (seq_leq (blk->start, hole->start))
985 /* Block covers hole. Remove hole */
986 if (seq_geq (blk->end, hole->end))
988 next_hole = scoreboard_next_hole (sb, hole);
990 /* Byte accounting: snd_una needs to be advanced */
995 if (seq_lt (ack, next_hole->start))
996 sb->snd_una_adv = next_hole->start - ack;
997 sb->last_bytes_delivered +=
998 next_hole->start - hole->end;
1002 ASSERT (seq_geq (sb->high_sacked, ack));
1003 sb->snd_una_adv = sb->high_sacked - ack;
1004 sb->last_bytes_delivered += sb->high_sacked - hole->end;
1008 scoreboard_remove_hole (sb, hole);
1011 /* Partial 'head' overlap */
1014 if (seq_gt (blk->end, hole->start))
1016 hole->start = blk->end;
1023 /* Hole must be split */
1024 if (seq_lt (blk->end, hole->end))
1026 hole_index = scoreboard_hole_index (sb, hole);
1027 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
1030 /* Pool might've moved */
1031 hole = scoreboard_get_hole (sb, hole_index);
1032 hole->end = blk->start;
1034 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
1036 else if (seq_lt (blk->start, hole->end))
1038 hole->end = blk->start;
1040 hole = scoreboard_next_hole (sb, hole);
1044 if (pool_elts (sb->holes) == 1)
1046 hole = scoreboard_first_hole (sb);
1047 if (hole->start == ack + sb->snd_una_adv
1048 && hole->end == tc->snd_una_max)
1049 scoreboard_remove_hole (sb, hole);
1052 scoreboard_update_bytes (tc, sb);
1053 sb->last_sacked_bytes = sb->sacked_bytes
1054 - (old_sacked_bytes - sb->last_bytes_delivered);
1055 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
1056 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
1057 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
1058 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
1059 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1060 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1061 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
1062 TCP_EVT_DBG (TCP_EVT_CC_SCOREBOARD, tc);
1066 * Try to update snd_wnd based on feedback received from peer.
1068 * If successful, and new window is 'effectively' 0, activate persist
1072 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1074 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1075 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1076 if (seq_lt (tc->snd_wl1, seq)
1077 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1079 tc->snd_wnd = snd_wnd;
1082 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
1084 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
1086 /* Set persist timer if not set and we just got 0 wnd */
1087 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1088 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1089 tcp_persist_timer_set (tc);
1093 tcp_persist_timer_reset (tc);
1094 if (PREDICT_FALSE (!tcp_in_recovery (tc) && tc->rto_boff > 0))
1097 tcp_update_rto (tc);
1104 * Init loss recovery/fast recovery.
1106 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1107 * updated in @ref tcp_cc_handle_event after fast retransmit
1110 tcp_cc_init_congestion (tcp_connection_t * tc)
1112 tcp_fastrecovery_on (tc);
1113 tc->snd_congestion = tc->snd_una_max;
1114 tc->cwnd_acc_bytes = 0;
1115 tc->snd_rxt_bytes = 0;
1116 tc->prev_ssthresh = tc->ssthresh;
1117 tc->prev_cwnd = tc->cwnd;
1118 tc->cc_algo->congestion (tc);
1119 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
1123 tcp_cc_recovery_exit (tcp_connection_t * tc)
1126 tcp_update_rto (tc);
1128 tc->snd_nxt = tc->snd_una_max;
1130 tcp_recovery_off (tc);
1131 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1135 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
1137 tc->cc_algo->recovered (tc);
1138 tc->snd_rxt_bytes = 0;
1139 tc->rcv_dupacks = 0;
1140 tc->snd_nxt = tc->snd_una_max;
1141 tc->snd_rxt_bytes = 0;
1144 tcp_fastrecovery_off (tc);
1145 tcp_fastrecovery_first_off (tc);
1147 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1151 tcp_cc_congestion_undo (tcp_connection_t * tc)
1153 tc->cwnd = tc->prev_cwnd;
1154 tc->ssthresh = tc->prev_ssthresh;
1155 tc->snd_nxt = tc->snd_una_max;
1156 tc->rcv_dupacks = 0;
1157 if (tcp_in_recovery (tc))
1158 tcp_cc_recovery_exit (tc);
1159 else if (tcp_in_fastrecovery (tc))
1160 tcp_cc_fastrecovery_exit (tc);
1161 ASSERT (tc->rto_boff == 0);
1162 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
1166 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1168 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1170 && tcp_opts_tstamp (&tc->rcv_opts)
1171 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1175 tcp_cc_is_spurious_fast_rxt (tcp_connection_t * tc)
1177 return (tcp_in_fastrecovery (tc)
1178 && tc->cwnd > tc->ssthresh + 3 * tc->snd_mss);
1182 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1184 return (tcp_cc_is_spurious_timeout_rxt (tc)
1185 || tcp_cc_is_spurious_fast_rxt (tc));
1189 tcp_cc_recover (tcp_connection_t * tc)
1191 ASSERT (tcp_in_cong_recovery (tc));
1192 if (tcp_cc_is_spurious_retransmit (tc))
1194 tcp_cc_congestion_undo (tc);
1198 if (tcp_in_recovery (tc))
1199 tcp_cc_recovery_exit (tc);
1200 else if (tcp_in_fastrecovery (tc))
1201 tcp_cc_fastrecovery_exit (tc);
1203 ASSERT (tc->rto_boff == 0);
1204 ASSERT (!tcp_in_cong_recovery (tc));
1205 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1210 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
1212 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1214 /* Congestion avoidance */
1215 tcp_cc_rcv_ack (tc);
1217 /* If a cumulative ack, make sure dupacks is 0 */
1218 tc->rcv_dupacks = 0;
1220 /* When dupacks hits the threshold we only enter fast retransmit if
1221 * cumulative ack covers more than snd_congestion. Should snd_una
1222 * wrap this test may fail under otherwise valid circumstances.
1223 * Therefore, proactively update snd_congestion when wrap detected. */
1225 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1226 && seq_gt (tc->snd_congestion, tc->snd_una)))
1227 tc->snd_congestion = tc->snd_una - 1;
1231 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1233 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1237 tcp_should_fastrecover (tcp_connection_t * tc)
1239 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1240 || tcp_should_fastrecover_sack (tc));
1244 tcp_program_fastretransmit (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1246 if (!(tc->flags & TCP_CONN_FRXT_PENDING))
1248 vec_add1 (wrk->pending_fast_rxt, tc->c_c_index);
1249 tc->flags |= TCP_CONN_FRXT_PENDING;
1254 tcp_do_fastretransmits (tcp_worker_ctx_t * wrk)
1256 u32 *ongoing_fast_rxt, burst_bytes, sent_bytes, thread_index;
1257 u32 max_burst_size, burst_size, n_segs = 0, n_segs_now;
1258 tcp_connection_t *tc;
1262 if (vec_len (wrk->pending_fast_rxt) == 0
1263 && vec_len (wrk->postponed_fast_rxt) == 0)
1266 thread_index = wrk->vm->thread_index;
1267 last_cpu_time = wrk->vm->clib_time.last_cpu_time;
1268 ongoing_fast_rxt = wrk->ongoing_fast_rxt;
1269 vec_append (ongoing_fast_rxt, wrk->postponed_fast_rxt);
1270 vec_append (ongoing_fast_rxt, wrk->pending_fast_rxt);
1272 _vec_len (wrk->postponed_fast_rxt) = 0;
1273 _vec_len (wrk->pending_fast_rxt) = 0;
1275 max_burst_size = VLIB_FRAME_SIZE / vec_len (ongoing_fast_rxt);
1276 max_burst_size = clib_max (max_burst_size, 1);
1278 for (i = 0; i < vec_len (ongoing_fast_rxt); i++)
1280 if (n_segs >= VLIB_FRAME_SIZE)
1282 vec_add1 (wrk->postponed_fast_rxt, ongoing_fast_rxt[i]);
1286 tc = tcp_connection_get (ongoing_fast_rxt[i], thread_index);
1287 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1289 if (!tcp_in_fastrecovery (tc))
1292 burst_size = clib_min (max_burst_size, VLIB_FRAME_SIZE - n_segs);
1293 burst_bytes = transport_connection_tx_pacer_burst (&tc->connection,
1295 burst_size = clib_min (burst_size, burst_bytes / tc->snd_mss);
1298 tcp_program_fastretransmit (wrk, tc);
1302 n_segs_now = tcp_fast_retransmit (wrk, tc, burst_size);
1303 sent_bytes = clib_min (n_segs_now * tc->snd_mss, burst_bytes);
1304 transport_connection_tx_pacer_update_bytes (&tc->connection,
1306 n_segs += n_segs_now;
1308 _vec_len (ongoing_fast_rxt) = 0;
1309 wrk->ongoing_fast_rxt = ongoing_fast_rxt;
1313 * One function to rule them all ... and in the darkness bind them
1316 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1320 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1322 if (tc->bytes_acked)
1324 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1328 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1329 * it account for the bytes that left the network.
1331 else if (is_dack && !tcp_in_recovery (tc))
1333 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1334 ASSERT (tc->snd_una != tc->snd_una_max
1335 || tc->sack_sb.last_sacked_bytes);
1339 /* Pure duplicate ack. If some data got acked, it's handled lower */
1340 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1342 ASSERT (tcp_in_fastrecovery (tc));
1343 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1346 else if (tcp_should_fastrecover (tc))
1350 ASSERT (!tcp_in_fastrecovery (tc));
1352 /* Heuristic to catch potential late dupacks
1353 * after fast retransmit exits */
1354 if (is_dack && tc->snd_una == tc->snd_congestion
1355 && timestamp_leq (tc->rcv_opts.tsecr, tc->tsecr_last_ack))
1357 tc->rcv_dupacks = 0;
1361 tcp_cc_init_congestion (tc);
1362 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1364 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1366 tc->cwnd = tc->ssthresh;
1367 scoreboard_init_high_rxt (&tc->sack_sb, tc->snd_una);
1371 /* Post retransmit update cwnd to ssthresh and account for the
1372 * three segments that have left the network and should've been
1373 * buffered at the receiver XXX */
1374 tc->cwnd = tc->ssthresh + 3 * tc->snd_mss;
1377 /* Constrain rate until we get a partial ack */
1378 pacer_wnd = clib_max (0.1 * tc->cwnd, 2 * tc->snd_mss);
1379 tcp_connection_tx_pacer_reset (tc, pacer_wnd,
1380 0 /* start bucket */ );
1381 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index),
1385 else if (!tc->bytes_acked
1386 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1388 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1394 /* Don't allow entry in fast recovery if still in recovery, for now */
1395 else if (0 && is_dack && tcp_in_recovery (tc))
1397 /* If of of the two conditions lower hold, reset dupacks because
1398 * we're probably after timeout (RFC6582 heuristics).
1399 * If Cumulative ack does not cover more than congestion threshold,
1401 * 1) The following doesn't hold: The congestion window is greater
1402 * than SMSS bytes and the difference between highest_ack
1403 * and prev_highest_ack is at most 4*SMSS bytes
1404 * 2) Echoed timestamp in the last non-dup ack does not equal the
1407 if (seq_leq (tc->snd_una, tc->snd_congestion)
1408 && ((!(tc->cwnd > tc->snd_mss
1409 && tc->bytes_acked <= 4 * tc->snd_mss))
1410 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1412 tc->rcv_dupacks = 0;
1417 if (!tc->bytes_acked)
1421 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1424 * Legitimate ACK. 1) See if we can exit recovery
1427 /* Update the pacing rate. For the first partial ack we move from
1428 * the artificially constrained rate to the one after congestion */
1429 tcp_connection_tx_pacer_update (tc);
1431 if (seq_geq (tc->snd_una, tc->snd_congestion))
1433 tcp_retransmit_timer_update (tc);
1435 /* If spurious return, we've already updated everything */
1436 if (tcp_cc_recover (tc))
1438 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1442 tc->snd_nxt = tc->snd_una_max;
1444 /* Treat as congestion avoidance ack */
1445 tcp_cc_rcv_ack (tc);
1450 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1453 /* XXX limit this only to first partial ack? */
1454 tcp_retransmit_timer_update (tc);
1456 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1457 * reset dupacks to 0. Also needed if in congestion recovery */
1458 tc->rcv_dupacks = 0;
1460 /* Post RTO timeout don't try anything fancy */
1461 if (tcp_in_recovery (tc))
1463 tcp_cc_rcv_ack (tc);
1464 transport_add_tx_event (&tc->connection);
1468 /* Remove retransmitted bytes that have been delivered */
1469 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1471 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1472 >= tc->sack_sb.last_bytes_delivered
1473 || (tc->flags & TCP_CONN_FINSNT));
1475 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1476 * remove sacked bytes delivered */
1477 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1479 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1480 - tc->sack_sb.last_bytes_delivered;
1481 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1482 tc->snd_rxt_bytes -= rxt_delivered;
1486 /* Apparently all retransmitted holes have been acked */
1487 tc->snd_rxt_bytes = 0;
1488 tc->sack_sb.high_rxt = tc->snd_una;
1493 tcp_fastrecovery_first_on (tc);
1494 /* Reuse last bytes delivered to track total bytes acked */
1495 tc->sack_sb.last_bytes_delivered += tc->bytes_acked;
1496 if (tc->snd_rxt_bytes > tc->bytes_acked)
1497 tc->snd_rxt_bytes -= tc->bytes_acked;
1499 tc->snd_rxt_bytes = 0;
1502 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1505 * Since this was a partial ack, try to retransmit some more data
1507 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1511 * Process incoming ACK
1514 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1515 tcp_header_t * th, u32 * error)
1517 u32 prev_snd_wnd, prev_snd_una;
1520 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1522 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1523 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1525 /* When we entered recovery, we reset snd_nxt to snd_una. Seems peer
1526 * still has the data so accept the ack */
1527 if (tcp_in_recovery (tc)
1528 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_congestion))
1530 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1531 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
1532 tc->snd_una_max = tc->snd_nxt;
1536 /* If we have outstanding data and this is within the window, accept it,
1537 * probably retransmit has timed out. Otherwise ACK segment and then
1539 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1541 tcp_program_ack (wrk, tc);
1542 *error = TCP_ERROR_ACK_FUTURE;
1543 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1544 vnet_buffer (b)->tcp.ack_number);
1548 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1549 vnet_buffer (b)->tcp.ack_number);
1551 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1554 /* If old ACK, probably it's an old dupack */
1555 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1557 *error = TCP_ERROR_ACK_OLD;
1558 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1559 vnet_buffer (b)->tcp.ack_number);
1560 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1561 tcp_cc_handle_event (tc, 1);
1562 /* Don't drop yet */
1567 * Looks okay, process feedback
1570 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1571 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1573 prev_snd_wnd = tc->snd_wnd;
1574 prev_snd_una = tc->snd_una;
1575 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1576 vnet_buffer (b)->tcp.ack_number,
1577 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1578 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1579 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1580 tcp_validate_txf_size (tc, tc->bytes_acked);
1582 if (tc->bytes_acked)
1584 tcp_program_dequeue (wrk, tc);
1585 tcp_update_rtt (tc, vnet_buffer (b)->tcp.ack_number);
1588 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1591 * Check if we have congestion event
1594 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1596 tcp_cc_handle_event (tc, is_dack);
1597 if (!tcp_in_cong_recovery (tc))
1599 *error = TCP_ERROR_ACK_OK;
1602 *error = TCP_ERROR_ACK_DUP;
1603 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1609 * Update congestion control (slow start/congestion avoidance)
1611 tcp_cc_update (tc, b);
1612 *error = TCP_ERROR_ACK_OK;
1617 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1619 if (!tcp_disconnect_pending (tc))
1621 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1622 tcp_disconnect_pending_on (tc);
1627 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1629 u32 thread_index, *pending_disconnects;
1630 tcp_connection_t *tc;
1633 if (!vec_len (wrk->pending_disconnects))
1636 thread_index = wrk->vm->thread_index;
1637 pending_disconnects = wrk->pending_disconnects;
1638 for (i = 0; i < vec_len (pending_disconnects); i++)
1640 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1641 tcp_disconnect_pending_off (tc);
1642 stream_session_disconnect_notify (&tc->connection);
1644 _vec_len (wrk->pending_disconnects) = 0;
1648 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1651 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1652 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1653 /* Account for the FIN if nothing else was received */
1654 if (vnet_buffer (b)->tcp.data_len == 0)
1656 tcp_program_ack (wrk, tc);
1657 tc->state = TCP_STATE_CLOSE_WAIT;
1658 tcp_program_disconnect (wrk, tc);
1659 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1660 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc);
1661 *error = TCP_ERROR_FIN_RCVD;
1665 tcp_sack_vector_is_sane (sack_block_t * sacks)
1668 for (i = 1; i < vec_len (sacks); i++)
1670 if (sacks[i - 1].end == sacks[i].start)
1677 * Build SACK list as per RFC2018.
1679 * Makes sure the first block contains the segment that generated the current
1680 * ACK and the following ones are the ones most recently reported in SACK
1683 * @param tc TCP connection for which the SACK list is updated
1684 * @param start Start sequence number of the newest SACK block
1685 * @param end End sequence of the newest SACK block
1688 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1690 sack_block_t *new_list = 0, *block = 0;
1693 /* If the first segment is ooo add it to the list. Last write might've moved
1694 * rcv_nxt over the first segment. */
1695 if (seq_lt (tc->rcv_nxt, start))
1697 vec_add2 (new_list, block, 1);
1698 block->start = start;
1702 /* Find the blocks still worth keeping. */
1703 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1705 /* Discard if rcv_nxt advanced beyond current block */
1706 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1709 /* Merge or drop if segment overlapped by the new segment */
1710 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1711 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1713 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1714 new_list[0].start = tc->snd_sacks[i].start;
1715 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1716 new_list[0].end = tc->snd_sacks[i].end;
1720 /* Save to new SACK list if we have space. */
1721 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1723 vec_add1 (new_list, tc->snd_sacks[i]);
1727 clib_warning ("sack discarded");
1731 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1733 /* Replace old vector with new one */
1734 vec_free (tc->snd_sacks);
1735 tc->snd_sacks = new_list;
1737 /* Segments should not 'touch' */
1738 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1742 tcp_sack_list_bytes (tcp_connection_t * tc)
1745 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1746 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1750 /** Enqueue data for delivery to application */
1752 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1755 int written, error = TCP_ERROR_ENQUEUED;
1757 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1759 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1760 1 /* queue event */ , 1);
1762 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1764 /* Update rcv_nxt */
1765 if (PREDICT_TRUE (written == data_len))
1767 tc->rcv_nxt += written;
1769 /* If more data written than expected, account for out-of-order bytes. */
1770 else if (written > data_len)
1772 tc->rcv_nxt += written;
1773 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1775 else if (written > 0)
1777 /* We've written something but FIFO is probably full now */
1778 tc->rcv_nxt += written;
1779 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1783 return TCP_ERROR_FIFO_FULL;
1786 /* Update SACK list if need be */
1787 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1789 /* Remove SACK blocks that have been delivered */
1790 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1796 /** Enqueue out-of-order data */
1798 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1801 stream_session_t *s0;
1804 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1807 /* Enqueue out-of-order data with relative offset */
1808 rv = session_enqueue_stream_connection (&tc->connection, b,
1809 vnet_buffer (b)->tcp.seq_number -
1810 tc->rcv_nxt, 0 /* queue event */ ,
1813 /* Nothing written */
1816 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1817 return TCP_ERROR_FIFO_FULL;
1820 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1822 /* Update SACK list if in use */
1823 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1825 ooo_segment_t *newest;
1828 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1830 /* Get the newest segment from the fifo */
1831 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1834 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1835 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1836 start = tc->rcv_nxt + offset;
1837 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1838 tcp_update_sack_list (tc, start, end);
1839 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1840 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1844 return TCP_ERROR_ENQUEUED_OOO;
1848 * Check if ACK could be delayed. If ack can be delayed, it should return
1849 * true for a full frame. If we're always acking return 0.
1852 tcp_can_delack (tcp_connection_t * tc)
1854 /* Send ack if ... */
1856 /* just sent a rcv wnd 0 */
1857 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1858 /* constrained to send ack */
1859 || (tc->flags & TCP_CONN_SNDACK) != 0
1860 /* we're almost out of tx wnd */
1861 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1868 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1870 u32 discard, first = b->current_length;
1871 vlib_main_t *vm = vlib_get_main ();
1873 /* Handle multi-buffer segments */
1874 if (n_bytes_to_drop > b->current_length)
1876 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1880 discard = clib_min (n_bytes_to_drop, b->current_length);
1881 vlib_buffer_advance (b, discard);
1882 b = vlib_get_buffer (vm, b->next_buffer);
1883 n_bytes_to_drop -= discard;
1885 while (n_bytes_to_drop);
1886 if (n_bytes_to_drop > first)
1887 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1890 vlib_buffer_advance (b, n_bytes_to_drop);
1891 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1896 * Receive buffer for connection and handle acks
1898 * It handles both in order or out-of-order data.
1901 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1904 u32 error, n_bytes_to_drop, n_data_bytes;
1906 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1907 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1908 ASSERT (n_data_bytes);
1910 /* Handle out-of-order data */
1911 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1913 /* Old sequence numbers allowed through because they overlapped
1915 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1917 /* Completely in the past (possible retransmit). Ack
1918 * retransmissions since we may not have any data to send */
1919 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1921 tcp_program_ack (wrk, tc);
1922 error = TCP_ERROR_SEGMENT_OLD;
1926 /* Chop off the bytes in the past and see if what is left
1927 * can be enqueued in order */
1928 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1929 n_data_bytes -= n_bytes_to_drop;
1930 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1931 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1933 error = TCP_ERROR_SEGMENT_OLD;
1939 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1940 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1941 tcp_program_dupack (wrk, tc);
1942 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1948 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1949 * segments can be enqueued after fifo tail offset changes. */
1950 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1951 if (tcp_can_delack (tc))
1953 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1954 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1958 tcp_program_ack (wrk, tc);
1966 tcp_header_t tcp_header;
1967 tcp_connection_t tcp_connection;
1971 format_tcp_rx_trace (u8 * s, va_list * args)
1973 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1974 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1975 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1976 u32 indent = format_get_indent (s);
1978 s = format (s, "%U\n%U%U",
1979 format_tcp_header, &t->tcp_header, 128,
1980 format_white_space, indent,
1981 format_tcp_connection, &t->tcp_connection, 1);
1987 format_tcp_rx_trace_short (u8 * s, va_list * args)
1989 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1990 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1991 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1993 s = format (s, "%d -> %d (%U)",
1994 clib_net_to_host_u16 (t->tcp_header.dst_port),
1995 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
1996 t->tcp_connection.state);
2002 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
2003 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
2007 clib_memcpy_fast (&t0->tcp_connection, tc0,
2008 sizeof (t0->tcp_connection));
2012 th0 = tcp_buffer_hdr (b0);
2014 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2018 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2019 vlib_frame_t * frame, u8 is_ip4)
2023 n_left = frame->n_vectors;
2024 from = vlib_frame_vector_args (frame);
2028 tcp_connection_t *tc0;
2035 b0 = vlib_get_buffer (vm, bi0);
2037 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2039 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2040 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2042 th0 = tcp_buffer_hdr (b0);
2043 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2052 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2053 u8 is_ip4, u32 evt, u32 val)
2056 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2058 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2061 #define tcp_maybe_inc_counter(node_id, err, count) \
2063 if (next0 != tcp_next_drop (is_ip4)) \
2064 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2065 tcp6_##node_id##_node.index, is_ip4, err, \
2068 #define tcp_inc_counter(node_id, err, count) \
2069 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2070 tcp6_##node_id##_node.index, is_ip4, \
2072 #define tcp_maybe_inc_err_counter(cnts, err) \
2074 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2076 #define tcp_inc_err_counter(cnts, err, val) \
2080 #define tcp_store_err_counters(node_id, cnts) \
2083 for (i = 0; i < TCP_N_ERROR; i++) \
2085 tcp_inc_counter(node_id, i, cnts[i]); \
2090 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2091 vlib_frame_t * frame, int is_ip4)
2093 u32 thread_index = vm->thread_index, errors = 0;
2094 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2095 u32 n_left_from, *from, *first_buffer;
2096 u16 err_counters[TCP_N_ERROR] = { 0 };
2099 if (node->flags & VLIB_NODE_FLAG_TRACE)
2100 tcp_established_trace_frame (vm, node, frame, is_ip4);
2102 first_buffer = from = vlib_frame_vector_args (frame);
2103 n_left_from = frame->n_vectors;
2105 while (n_left_from > 0)
2107 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2109 tcp_header_t *th0 = 0;
2110 tcp_connection_t *tc0;
2112 if (n_left_from > 1)
2115 pb = vlib_get_buffer (vm, from[1]);
2116 vlib_prefetch_buffer_header (pb, LOAD);
2117 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2124 b0 = vlib_get_buffer (vm, bi0);
2125 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2128 if (PREDICT_FALSE (tc0 == 0))
2130 error0 = TCP_ERROR_INVALID_CONNECTION;
2134 th0 = tcp_buffer_hdr (b0);
2135 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
2136 * dangling reference. */
2137 is_fin = tcp_is_fin (th0);
2139 /* SYNs, FINs and data consume sequence numbers */
2140 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2141 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
2143 /* TODO header prediction fast path */
2145 /* 1-4: check SEQ, RST, SYN */
2146 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2148 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2152 /* 5: check the ACK field */
2153 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2156 /* 6: check the URG bit TODO */
2158 /* 7: process the segment text */
2159 if (vnet_buffer (b0)->tcp.data_len)
2160 error0 = tcp_segment_rcv (wrk, tc0, b0);
2162 /* 8: check the FIN bit */
2163 if (PREDICT_FALSE (is_fin))
2164 tcp_rcv_fin (wrk, tc0, b0, &error0);
2167 tcp_inc_err_counter (err_counters, error0, 1);
2170 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2172 err_counters[TCP_ERROR_MSG_QUEUE_FULL] = errors;
2173 tcp_store_err_counters (established, err_counters);
2174 tcp_handle_postponed_dequeues (wrk);
2175 tcp_handle_disconnects (wrk);
2176 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2178 return frame->n_vectors;
2182 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2183 vlib_frame_t * from_frame)
2185 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2189 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2190 vlib_frame_t * from_frame)
2192 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2196 VLIB_REGISTER_NODE (tcp4_established_node) =
2198 .function = tcp4_established,
2199 .name = "tcp4-established",
2200 /* Takes a vector of packets. */
2201 .vector_size = sizeof (u32),
2202 .n_errors = TCP_N_ERROR,
2203 .error_strings = tcp_error_strings,
2204 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2207 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2208 foreach_tcp_state_next
2211 .format_trace = format_tcp_rx_trace_short,
2215 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
2218 VLIB_REGISTER_NODE (tcp6_established_node) =
2220 .function = tcp6_established,
2221 .name = "tcp6-established",
2222 /* Takes a vector of packets. */
2223 .vector_size = sizeof (u32),
2224 .n_errors = TCP_N_ERROR,
2225 .error_strings = tcp_error_strings,
2226 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2229 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2230 foreach_tcp_state_next
2233 .format_trace = format_tcp_rx_trace_short,
2238 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
2240 vlib_node_registration_t tcp4_syn_sent_node;
2241 vlib_node_registration_t tcp6_syn_sent_node;
2244 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2246 transport_connection_t *tmp = 0;
2253 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2256 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2257 && (tc->state == TCP_STATE_LISTEN
2258 || tc->c_rmt_port == hdr->src_port));
2262 handle = session_lookup_half_open_handle (&tc->connection);
2263 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2264 tc->c_proto, tc->c_is_ip4);
2268 if (tmp->lcl_port == hdr->dst_port
2269 && tmp->rmt_port == hdr->src_port)
2271 TCP_DBG ("half-open is valid!");
2279 * Lookup transport connection
2281 static tcp_connection_t *
2282 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2286 transport_connection_t *tconn;
2287 tcp_connection_t *tc;
2292 ip4 = vlib_buffer_get_current (b);
2293 tcp = ip4_next_header (ip4);
2294 tconn = session_lookup_connection_wt4 (fib_index,
2299 TRANSPORT_PROTO_TCP,
2300 thread_index, &is_filtered);
2301 tc = tcp_get_connection_from_transport (tconn);
2302 ASSERT (tcp_lookup_is_valid (tc, tcp));
2307 ip6 = vlib_buffer_get_current (b);
2308 tcp = ip6_next_header (ip6);
2309 tconn = session_lookup_connection_wt6 (fib_index,
2314 TRANSPORT_PROTO_TCP,
2315 thread_index, &is_filtered);
2316 tc = tcp_get_connection_from_transport (tconn);
2317 ASSERT (tcp_lookup_is_valid (tc, tcp));
2323 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2324 vlib_frame_t * from_frame, int is_ip4)
2326 tcp_main_t *tm = vnet_get_tcp_main ();
2327 u32 n_left_from, *from, *first_buffer, errors = 0;
2328 u32 my_thread_index = vm->thread_index;
2329 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2331 from = first_buffer = vlib_frame_vector_args (from_frame);
2332 n_left_from = from_frame->n_vectors;
2334 while (n_left_from > 0)
2336 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2337 tcp_connection_t *tc0, *new_tc0;
2338 tcp_header_t *tcp0 = 0;
2346 b0 = vlib_get_buffer (vm, bi0);
2348 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2349 if (PREDICT_FALSE (tc0 == 0))
2351 error0 = TCP_ERROR_INVALID_CONNECTION;
2355 /* Half-open completed recently but the connection was't removed
2356 * yet by the owning thread */
2357 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2359 /* Make sure the connection actually exists */
2360 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2361 my_thread_index, is_ip4));
2365 ack0 = vnet_buffer (b0)->tcp.ack_number;
2366 seq0 = vnet_buffer (b0)->tcp.seq_number;
2367 tcp0 = tcp_buffer_hdr (b0);
2369 /* Crude check to see if the connection handle does not match
2370 * the packet. Probably connection just switched to established */
2371 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2372 || tcp0->src_port != tc0->c_rmt_port))
2374 error0 = TCP_ERROR_INVALID_CONNECTION;
2378 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2379 && !tcp_syn (tcp0)))
2381 error0 = TCP_ERROR_SEGMENT_INVALID;
2385 /* SYNs, FINs and data consume sequence numbers */
2386 vnet_buffer (b0)->tcp.seq_end =
2387 seq0 + tcp_is_syn (tcp0) + tcp_is_fin (tcp0) +
2388 vnet_buffer (b0)->tcp.data_len;
2391 * 1. check the ACK bit
2395 * If the ACK bit is set
2396 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2397 * the RST bit is set, if so drop the segment and return)
2398 * <SEQ=SEG.ACK><CTL=RST>
2399 * and discard the segment. Return.
2400 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2404 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2406 if (!tcp_rst (tcp0))
2407 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2408 error0 = TCP_ERROR_RCV_WND;
2412 /* Make sure ACK is valid */
2413 if (seq_gt (tc0->snd_una, ack0))
2415 error0 = TCP_ERROR_ACK_INVALID;
2421 * 2. check the RST bit
2426 /* If ACK is acceptable, signal client that peer is not
2427 * willing to accept connection and drop connection*/
2429 tcp_connection_reset (tc0);
2430 error0 = TCP_ERROR_RST_RCVD;
2435 * 3. check the security and precedence (skipped)
2439 * 4. check the SYN bit
2442 /* No SYN flag. Drop. */
2443 if (!tcp_syn (tcp0))
2445 clib_warning ("not synack");
2446 error0 = TCP_ERROR_SEGMENT_INVALID;
2451 if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1))
2453 clib_warning ("options parse fail");
2454 error0 = TCP_ERROR_OPTIONS;
2458 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2459 * current thread pool. */
2460 pool_get (tm->connections[my_thread_index], new_tc0);
2461 clib_memcpy_fast (new_tc0, tc0, sizeof (*new_tc0));
2462 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2463 new_tc0->c_thread_index = my_thread_index;
2464 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2465 new_tc0->irs = seq0;
2466 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
2467 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2468 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2470 /* If this is not the owning thread, wait for syn retransmit to
2471 * expire and cleanup then */
2472 if (tcp_half_open_connection_cleanup (tc0))
2473 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2475 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2477 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2478 new_tc0->tsval_recent_age = tcp_time_now ();
2481 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2482 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2484 new_tc0->rcv_wscale = 0;
2486 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2487 << new_tc0->snd_wscale;
2488 new_tc0->snd_wl1 = seq0;
2489 new_tc0->snd_wl2 = ack0;
2491 tcp_connection_init_vars (new_tc0);
2493 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2494 if (PREDICT_TRUE (tcp_ack (tcp0)))
2496 /* Our SYN is ACKed: we have iss < ack = snd_una */
2498 /* TODO Dequeue acknowledged segments if we support Fast Open */
2499 new_tc0->snd_una = ack0;
2500 new_tc0->state = TCP_STATE_ESTABLISHED;
2502 /* Make sure las is initialized for the wnd computation */
2503 new_tc0->rcv_las = new_tc0->rcv_nxt;
2505 /* Notify app that we have connection. If session layer can't
2506 * allocate session send reset */
2507 if (session_stream_connect_notify (&new_tc0->connection, 0))
2509 clib_warning ("connect notify fail");
2510 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2511 tcp_connection_cleanup (new_tc0);
2515 new_tc0->tx_fifo_size =
2516 transport_tx_fifo_size (&new_tc0->connection);
2517 /* Update rtt with the syn-ack sample */
2518 tcp_estimate_initial_rtt (new_tc0);
2519 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2520 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2522 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2525 new_tc0->state = TCP_STATE_SYN_RCVD;
2527 /* Notify app that we have connection */
2528 if (session_stream_connect_notify (&new_tc0->connection, 0))
2530 tcp_connection_cleanup (new_tc0);
2531 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2532 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2536 new_tc0->tx_fifo_size =
2537 transport_tx_fifo_size (&new_tc0->connection);
2538 new_tc0->rtt_ts = 0;
2539 tcp_init_snd_vars (new_tc0);
2540 tcp_send_synack (new_tc0);
2541 error0 = TCP_ERROR_SYNS_RCVD;
2545 /* Read data, if any */
2546 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2548 clib_warning ("rcvd data in syn-sent");
2549 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2550 if (error0 == TCP_ERROR_ACK_OK)
2551 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2555 tcp_program_ack (wrk, new_tc0);
2560 tcp_inc_counter (syn_sent, error0, 1);
2561 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2563 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2564 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2565 clib_memcpy_fast (&t0->tcp_connection, tc0,
2566 sizeof (t0->tcp_connection));
2570 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2572 tcp_inc_counter (syn_sent, TCP_ERROR_MSG_QUEUE_FULL, errors);
2573 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2575 return from_frame->n_vectors;
2579 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2580 vlib_frame_t * from_frame)
2582 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2586 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2587 vlib_frame_t * from_frame)
2589 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2593 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2595 .function = tcp4_syn_sent,
2596 .name = "tcp4-syn-sent",
2597 /* Takes a vector of packets. */
2598 .vector_size = sizeof (u32),
2599 .n_errors = TCP_N_ERROR,
2600 .error_strings = tcp_error_strings,
2601 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2604 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2605 foreach_tcp_state_next
2608 .format_trace = format_tcp_rx_trace_short,
2612 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2615 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2617 .function = tcp6_syn_sent_rcv,
2618 .name = "tcp6-syn-sent",
2619 /* Takes a vector of packets. */
2620 .vector_size = sizeof (u32),
2621 .n_errors = TCP_N_ERROR,
2622 .error_strings = tcp_error_strings,
2623 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2626 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2627 foreach_tcp_state_next
2630 .format_trace = format_tcp_rx_trace_short,
2634 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2636 vlib_node_registration_t tcp4_rcv_process_node;
2637 vlib_node_registration_t tcp6_rcv_process_node;
2640 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2641 * as per RFC793 p. 64
2644 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2645 vlib_frame_t * from_frame, int is_ip4)
2647 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2648 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2649 u32 n_left_from, *from, max_dequeue;
2651 from = first_buffer = vlib_frame_vector_args (from_frame);
2652 n_left_from = from_frame->n_vectors;
2654 while (n_left_from > 0)
2656 u32 bi0, error0 = TCP_ERROR_NONE;
2657 tcp_header_t *tcp0 = 0;
2658 tcp_connection_t *tc0;
2666 b0 = vlib_get_buffer (vm, bi0);
2667 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2669 if (PREDICT_FALSE (tc0 == 0))
2671 error0 = TCP_ERROR_INVALID_CONNECTION;
2675 tcp0 = tcp_buffer_hdr (b0);
2676 is_fin0 = tcp_is_fin (tcp0);
2678 /* SYNs, FINs and data consume sequence numbers */
2679 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2680 + tcp_is_syn (tcp0) + is_fin0 + vnet_buffer (b0)->tcp.data_len;
2684 tcp_connection_t *tmp;
2685 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2687 if (tmp->state != tc0->state)
2689 clib_warning ("state changed");
2695 * Special treatment for CLOSED
2697 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2699 error0 = TCP_ERROR_CONNECTION_CLOSED;
2704 * For all other states (except LISTEN)
2707 /* 1-4: check SEQ, RST, SYN */
2708 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2711 /* 5: check the ACK field */
2714 case TCP_STATE_SYN_RCVD:
2716 * If the segment acknowledgment is not acceptable, form a
2718 * <SEQ=SEG.ACK><CTL=RST>
2721 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2723 tcp_connection_reset (tc0);
2724 error0 = TCP_ERROR_ACK_INVALID;
2728 /* Make sure the ack is exactly right */
2729 if (tc0->rcv_nxt != vnet_buffer (b0)->tcp.seq_number || is_fin0
2730 || vnet_buffer (b0)->tcp.data_len)
2732 tcp_connection_reset (tc0);
2733 error0 = TCP_ERROR_SEGMENT_INVALID;
2737 /* Update rtt and rto */
2738 tcp_estimate_initial_rtt (tc0);
2740 /* Switch state to ESTABLISHED */
2741 tc0->state = TCP_STATE_ESTABLISHED;
2742 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2744 /* Initialize session variables */
2745 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2746 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2747 << tc0->rcv_opts.wscale;
2748 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2749 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2751 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2752 tcp_retransmit_timer_reset (tc0);
2753 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2754 if (stream_session_accept_notify (&tc0->connection))
2756 error0 = TCP_ERROR_MSG_QUEUE_FULL;
2757 tcp_connection_reset (tc0);
2760 error0 = TCP_ERROR_ACK_OK;
2762 case TCP_STATE_ESTABLISHED:
2763 /* We can get packets in established state here because they
2764 * were enqueued before state change */
2765 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2769 case TCP_STATE_FIN_WAIT_1:
2770 /* In addition to the processing for the ESTABLISHED state, if
2771 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2772 * continue processing in that state. */
2773 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2776 /* Still have to send the FIN */
2777 if (tc0->flags & TCP_CONN_FINPNDG)
2779 /* TX fifo finally drained */
2780 max_dequeue = session_tx_fifo_max_dequeue (&tc0->connection);
2781 if (max_dequeue <= tc0->burst_acked)
2784 /* If FIN is ACKed */
2785 else if (tc0->snd_una == tc0->snd_una_max)
2787 tc0->state = TCP_STATE_FIN_WAIT_2;
2788 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2790 /* Stop all retransmit timers because we have nothing more
2791 * to send. Enable waitclose though because we're willing to
2792 * wait for peer's FIN but not indefinitely. */
2793 tcp_connection_timers_reset (tc0);
2794 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2796 /* Don't try to deq the FIN acked */
2797 if (tc0->burst_acked > 1)
2798 stream_session_dequeue_drop (&tc0->connection,
2799 tc0->burst_acked - 1);
2800 tc0->burst_acked = 0;
2803 case TCP_STATE_FIN_WAIT_2:
2804 /* In addition to the processing for the ESTABLISHED state, if
2805 * the retransmission queue is empty, the user's CLOSE can be
2806 * acknowledged ("ok") but do not delete the TCB. */
2807 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2809 tc0->burst_acked = 0;
2811 case TCP_STATE_CLOSE_WAIT:
2812 /* Do the same processing as for the ESTABLISHED state. */
2813 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2816 if (tc0->flags & TCP_CONN_FINPNDG)
2818 /* TX fifo finally drained */
2819 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2822 tcp_connection_timers_reset (tc0);
2823 tc0->state = TCP_STATE_LAST_ACK;
2824 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2825 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2829 case TCP_STATE_CLOSING:
2830 /* In addition to the processing for the ESTABLISHED state, if
2831 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2832 * otherwise ignore the segment. */
2833 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2836 tc0->state = TCP_STATE_TIME_WAIT;
2837 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2838 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2842 case TCP_STATE_LAST_ACK:
2843 /* The only thing that [should] arrive in this state is an
2844 * acknowledgment of our FIN. If our FIN is now acknowledged,
2845 * delete the TCB, enter the CLOSED state, and return. */
2847 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2849 error0 = TCP_ERROR_ACK_INVALID;
2852 error0 = TCP_ERROR_ACK_OK;
2853 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2854 /* Apparently our ACK for the peer's FIN was lost */
2855 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2861 tc0->state = TCP_STATE_CLOSED;
2862 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2864 /* Don't free the connection from the data path since
2865 * we can't ensure that we have no packets already enqueued
2866 * to output. Rely instead on the waitclose timer */
2867 tcp_connection_timers_reset (tc0);
2868 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2873 case TCP_STATE_TIME_WAIT:
2874 /* The only thing that can arrive in this state is a
2875 * retransmission of the remote FIN. Acknowledge it, and restart
2876 * the 2 MSL timeout. */
2878 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2881 tcp_program_ack (wrk, tc0);
2882 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2890 /* 6: check the URG bit TODO */
2892 /* 7: process the segment text */
2895 case TCP_STATE_ESTABLISHED:
2896 case TCP_STATE_FIN_WAIT_1:
2897 case TCP_STATE_FIN_WAIT_2:
2898 if (vnet_buffer (b0)->tcp.data_len)
2899 error0 = tcp_segment_rcv (wrk, tc0, b0);
2903 case TCP_STATE_CLOSE_WAIT:
2904 case TCP_STATE_CLOSING:
2905 case TCP_STATE_LAST_ACK:
2906 case TCP_STATE_TIME_WAIT:
2907 /* This should not occur, since a FIN has been received from the
2908 * remote side. Ignore the segment text. */
2912 /* 8: check the FIN bit */
2918 case TCP_STATE_ESTABLISHED:
2919 tcp_rcv_fin (wrk, tc0, b0, &error0);
2921 case TCP_STATE_SYN_RCVD:
2922 /* Send FIN-ACK, enter LAST-ACK and because the app was not
2923 * notified yet, set a cleanup timer instead of relying on
2924 * disconnect notify and the implicit close call. */
2925 tcp_connection_timers_reset (tc0);
2928 tc0->state = TCP_STATE_LAST_ACK;
2929 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2930 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2932 case TCP_STATE_CLOSE_WAIT:
2933 case TCP_STATE_CLOSING:
2934 case TCP_STATE_LAST_ACK:
2937 case TCP_STATE_FIN_WAIT_1:
2938 tc0->state = TCP_STATE_CLOSING;
2939 tcp_program_ack (wrk, tc0);
2940 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2941 /* Wait for ACK but not forever */
2942 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2944 case TCP_STATE_FIN_WAIT_2:
2945 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2946 tc0->state = TCP_STATE_TIME_WAIT;
2947 tcp_connection_timers_reset (tc0);
2948 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2949 tcp_program_ack (wrk, tc0);
2950 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2952 case TCP_STATE_TIME_WAIT:
2953 /* Remain in the TIME-WAIT state. Restart the time-wait
2956 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2959 error0 = TCP_ERROR_FIN_RCVD;
2960 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2964 tcp_inc_counter (rcv_process, error0, 1);
2965 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2967 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2968 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2972 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2974 tcp_inc_counter (rcv_process, TCP_ERROR_MSG_QUEUE_FULL, errors);
2975 tcp_handle_postponed_dequeues (wrk);
2976 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2978 return from_frame->n_vectors;
2982 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2983 vlib_frame_t * from_frame)
2985 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2989 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2990 vlib_frame_t * from_frame)
2992 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2996 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2998 .function = tcp4_rcv_process,
2999 .name = "tcp4-rcv-process",
3000 /* Takes a vector of packets. */
3001 .vector_size = sizeof (u32),
3002 .n_errors = TCP_N_ERROR,
3003 .error_strings = tcp_error_strings,
3004 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3007 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3008 foreach_tcp_state_next
3011 .format_trace = format_tcp_rx_trace_short,
3015 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
3018 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
3020 .function = tcp6_rcv_process,
3021 .name = "tcp6-rcv-process",
3022 /* Takes a vector of packets. */
3023 .vector_size = sizeof (u32),
3024 .n_errors = TCP_N_ERROR,
3025 .error_strings = tcp_error_strings,
3026 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3029 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3030 foreach_tcp_state_next
3033 .format_trace = format_tcp_rx_trace_short,
3037 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
3039 vlib_node_registration_t tcp4_listen_node;
3040 vlib_node_registration_t tcp6_listen_node;
3043 * LISTEN state processing as per RFC 793 p. 65
3046 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3047 vlib_frame_t * from_frame, int is_ip4)
3049 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3050 u32 my_thread_index = vm->thread_index;
3052 from = first_buffer = vlib_frame_vector_args (from_frame);
3053 n_left_from = from_frame->n_vectors;
3055 while (n_left_from > 0)
3060 tcp_header_t *th0 = 0;
3061 tcp_connection_t *lc0;
3064 tcp_connection_t *child0;
3065 u32 error0 = TCP_ERROR_NONE;
3071 b0 = vlib_get_buffer (vm, bi0);
3072 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3076 ip40 = vlib_buffer_get_current (b0);
3077 th0 = ip4_next_header (ip40);
3081 ip60 = vlib_buffer_get_current (b0);
3082 th0 = ip6_next_header (ip60);
3085 /* Create child session. For syn-flood protection use filter */
3087 /* 1. first check for an RST: handled in dispatch */
3088 /* if (tcp_rst (th0))
3092 /* 2. second check for an ACK: handled in dispatch */
3093 /* if (tcp_ack (th0))
3095 tcp_send_reset (b0, is_ip4);
3100 /* 3. check for a SYN (did that already) */
3102 /* Make sure connection wasn't just created */
3103 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3105 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3107 error0 = TCP_ERROR_CREATE_EXISTS;
3111 /* Create child session and send SYN-ACK */
3112 child0 = tcp_connection_alloc (my_thread_index);
3113 child0->c_lcl_port = th0->dst_port;
3114 child0->c_rmt_port = th0->src_port;
3115 child0->c_is_ip4 = is_ip4;
3116 child0->state = TCP_STATE_SYN_RCVD;
3117 child0->c_fib_index = lc0->c_fib_index;
3121 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3122 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3126 clib_memcpy_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3127 sizeof (ip6_address_t));
3128 clib_memcpy_fast (&child0->c_rmt_ip6, &ip60->src_address,
3129 sizeof (ip6_address_t));
3132 if (tcp_options_parse (th0, &child0->rcv_opts, 1))
3134 error0 = TCP_ERROR_OPTIONS;
3135 tcp_connection_free (child0);
3139 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3140 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3141 child0->rcv_las = child0->rcv_nxt;
3142 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3144 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3145 * segments are used to initialize PAWS. */
3146 if (tcp_opts_tstamp (&child0->rcv_opts))
3148 child0->tsval_recent = child0->rcv_opts.tsval;
3149 child0->tsval_recent_age = tcp_time_now ();
3152 if (tcp_opts_wscale (&child0->rcv_opts))
3153 child0->snd_wscale = child0->rcv_opts.wscale;
3155 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3156 << child0->snd_wscale;
3157 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3158 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3160 tcp_connection_init_vars (child0);
3161 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
3163 if (stream_session_accept (&child0->connection, lc0->c_s_index,
3166 tcp_connection_cleanup (child0);
3167 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3171 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3172 tcp_send_synack (child0);
3173 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
3177 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3179 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3180 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3181 clib_memcpy_fast (&t0->tcp_connection, lc0,
3182 sizeof (t0->tcp_connection));
3185 n_syns += (error0 == TCP_ERROR_NONE);
3188 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3189 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3191 return from_frame->n_vectors;
3195 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3196 vlib_frame_t * from_frame)
3198 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3202 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3203 vlib_frame_t * from_frame)
3205 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3209 VLIB_REGISTER_NODE (tcp4_listen_node) =
3211 .function = tcp4_listen,
3212 .name = "tcp4-listen",
3213 /* Takes a vector of packets. */
3214 .vector_size = sizeof (u32),
3215 .n_errors = TCP_N_ERROR,
3216 .error_strings = tcp_error_strings,
3217 .n_next_nodes = TCP_LISTEN_N_NEXT,
3220 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3221 foreach_tcp_state_next
3224 .format_trace = format_tcp_rx_trace_short,
3228 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
3231 VLIB_REGISTER_NODE (tcp6_listen_node) =
3233 .function = tcp6_listen,
3234 .name = "tcp6-listen",
3235 /* Takes a vector of packets. */
3236 .vector_size = sizeof (u32),
3237 .n_errors = TCP_N_ERROR,
3238 .error_strings = tcp_error_strings,
3239 .n_next_nodes = TCP_LISTEN_N_NEXT,
3242 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3243 foreach_tcp_state_next
3246 .format_trace = format_tcp_rx_trace_short,
3250 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
3252 vlib_node_registration_t tcp4_input_node;
3253 vlib_node_registration_t tcp6_input_node;
3255 typedef enum _tcp_input_next
3257 TCP_INPUT_NEXT_DROP,
3258 TCP_INPUT_NEXT_LISTEN,
3259 TCP_INPUT_NEXT_RCV_PROCESS,
3260 TCP_INPUT_NEXT_SYN_SENT,
3261 TCP_INPUT_NEXT_ESTABLISHED,
3262 TCP_INPUT_NEXT_RESET,
3263 TCP_INPUT_NEXT_PUNT,
3267 #define foreach_tcp4_input_next \
3268 _ (DROP, "ip4-drop") \
3269 _ (LISTEN, "tcp4-listen") \
3270 _ (RCV_PROCESS, "tcp4-rcv-process") \
3271 _ (SYN_SENT, "tcp4-syn-sent") \
3272 _ (ESTABLISHED, "tcp4-established") \
3273 _ (RESET, "tcp4-reset") \
3274 _ (PUNT, "ip4-punt")
3276 #define foreach_tcp6_input_next \
3277 _ (DROP, "ip6-drop") \
3278 _ (LISTEN, "tcp6-listen") \
3279 _ (RCV_PROCESS, "tcp6-rcv-process") \
3280 _ (SYN_SENT, "tcp6-syn-sent") \
3281 _ (ESTABLISHED, "tcp6-established") \
3282 _ (RESET, "tcp6-reset") \
3283 _ (PUNT, "ip6-punt")
3285 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3288 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3289 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3291 tcp_connection_t *tc;
3296 for (i = 0; i < n_bufs; i++)
3298 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3300 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3301 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3303 tcp = vlib_buffer_get_current (bs[i]);
3304 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3310 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3312 if (*error == TCP_ERROR_FILTERED)
3314 *next = TCP_INPUT_NEXT_DROP;
3316 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3318 *next = TCP_INPUT_NEXT_PUNT;
3319 *error = TCP_ERROR_PUNT;
3323 *next = TCP_INPUT_NEXT_RESET;
3324 *error = TCP_ERROR_NO_LISTENER;
3328 static inline tcp_connection_t *
3329 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3332 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3333 int n_advance_bytes, n_data_bytes;
3334 transport_connection_t *tc;
3340 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3341 int ip_hdr_bytes = ip4_header_bytes (ip4);
3342 if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
3344 *error = TCP_ERROR_LENGTH;
3347 tcp = ip4_next_header (ip4);
3348 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3349 n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
3350 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3352 /* Length check. Checksum computed by ipx_local no need to compute again */
3353 if (PREDICT_FALSE (n_data_bytes < 0))
3355 *error = TCP_ERROR_LENGTH;
3359 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3360 &ip4->src_address, tcp->dst_port,
3361 tcp->src_port, TRANSPORT_PROTO_TCP,
3362 thread_index, &is_filtered);
3366 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3367 if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
3369 *error = TCP_ERROR_LENGTH;
3372 tcp = ip6_next_header (ip6);
3373 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3374 n_advance_bytes = tcp_header_bytes (tcp);
3375 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3377 n_advance_bytes += sizeof (ip6[0]);
3379 if (PREDICT_FALSE (n_data_bytes < 0))
3381 *error = TCP_ERROR_LENGTH;
3385 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3386 &ip6->src_address, tcp->dst_port,
3387 tcp->src_port, TRANSPORT_PROTO_TCP,
3388 thread_index, &is_filtered);
3391 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3392 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3393 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3394 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3395 vnet_buffer (b)->tcp.flags = 0;
3397 *error = is_filtered ? TCP_ERROR_FILTERED : *error;
3399 return tcp_get_connection_from_transport (tc);
3403 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3404 vlib_buffer_t * b, u16 * next, u32 * error)
3409 tcp = tcp_buffer_hdr (b);
3410 flags = tcp->flags & filter_flags;
3411 *next = tm->dispatch_table[tc->state][flags].next;
3412 *error = tm->dispatch_table[tc->state][flags].error;
3414 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3415 || *next == TCP_INPUT_NEXT_RESET))
3417 /* Overload tcp flags to store state */
3418 tcp_state_t state = tc->state;
3419 vnet_buffer (b)->tcp.flags = tc->state;
3421 if (*error == TCP_ERROR_DISPATCH)
3422 clib_warning ("tcp conn %u disp error state %U flags %U",
3423 tc->c_c_index, format_tcp_state, state,
3424 format_tcp_flags, (int) flags);
3429 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3430 vlib_frame_t * frame, int is_ip4)
3432 u32 n_left_from, *from, thread_index = vm->thread_index;
3433 tcp_main_t *tm = vnet_get_tcp_main ();
3434 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3435 u16 nexts[VLIB_FRAME_SIZE], *next;
3437 tcp_set_time_now (tcp_get_worker (thread_index));
3439 from = vlib_frame_vector_args (frame);
3440 n_left_from = frame->n_vectors;
3441 vlib_get_buffers (vm, from, bufs, n_left_from);
3446 while (n_left_from >= 4)
3448 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3449 tcp_connection_t *tc0, *tc1;
3452 vlib_prefetch_buffer_header (b[2], STORE);
3453 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3455 vlib_prefetch_buffer_header (b[3], STORE);
3456 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3459 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3461 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3462 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4);
3464 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3466 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3467 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3469 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3470 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3472 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3473 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3477 if (PREDICT_TRUE (tc0 != 0))
3479 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3480 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3481 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3484 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3486 if (PREDICT_TRUE (tc1 != 0))
3488 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3489 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3490 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3493 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3500 while (n_left_from > 0)
3502 tcp_connection_t *tc0;
3503 u32 error0 = TCP_ERROR_NO_LISTENER;
3505 if (n_left_from > 1)
3507 vlib_prefetch_buffer_header (b[1], STORE);
3508 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3511 next[0] = TCP_INPUT_NEXT_DROP;
3512 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3513 if (PREDICT_TRUE (tc0 != 0))
3515 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3516 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3517 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3520 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3527 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3528 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3530 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3531 return frame->n_vectors;
3535 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3536 vlib_frame_t * from_frame)
3538 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3542 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3543 vlib_frame_t * from_frame)
3545 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3549 VLIB_REGISTER_NODE (tcp4_input_node) =
3551 .function = tcp4_input,
3552 .name = "tcp4-input",
3553 /* Takes a vector of packets. */
3554 .vector_size = sizeof (u32),
3555 .n_errors = TCP_N_ERROR,
3556 .error_strings = tcp_error_strings,
3557 .n_next_nodes = TCP_INPUT_N_NEXT,
3560 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3561 foreach_tcp4_input_next
3564 .format_buffer = format_tcp_header,
3565 .format_trace = format_tcp_rx_trace,
3569 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3572 VLIB_REGISTER_NODE (tcp6_input_node) =
3574 .function = tcp6_input,
3575 .name = "tcp6-input",
3576 /* Takes a vector of packets. */
3577 .vector_size = sizeof (u32),
3578 .n_errors = TCP_N_ERROR,
3579 .error_strings = tcp_error_strings,
3580 .n_next_nodes = TCP_INPUT_N_NEXT,
3583 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3584 foreach_tcp6_input_next
3587 .format_buffer = format_tcp_header,
3588 .format_trace = format_tcp_rx_trace,
3592 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3595 tcp_dispatch_table_init (tcp_main_t * tm)
3598 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3599 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3601 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3602 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3605 #define _(t,f,n,e) \
3607 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3608 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3611 /* RFC 793: In LISTEN if RST drop and if ACK return RST */
3612 _(LISTEN, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3613 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_ACK_INVALID);
3614 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_INVALID_CONNECTION);
3615 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3616 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3617 TCP_ERROR_ACK_INVALID);
3618 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3619 TCP_ERROR_SEGMENT_INVALID);
3620 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3621 TCP_ERROR_SEGMENT_INVALID);
3622 _(LISTEN, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3623 TCP_ERROR_INVALID_CONNECTION);
3624 _(LISTEN, TCP_FLAG_FIN, TCP_INPUT_NEXT_RESET, TCP_ERROR_SEGMENT_INVALID);
3625 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3626 TCP_ERROR_SEGMENT_INVALID);
3627 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3628 TCP_ERROR_SEGMENT_INVALID);
3629 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3631 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_DROP,
3632 TCP_ERROR_SEGMENT_INVALID);
3633 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3634 TCP_ERROR_SEGMENT_INVALID);
3635 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3636 TCP_ERROR_SEGMENT_INVALID);
3637 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3638 TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3639 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3640 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3641 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3642 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3644 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3645 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3647 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3649 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3650 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3651 _(SYN_RCVD, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3652 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3654 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3656 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3657 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3658 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3660 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3661 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3662 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3663 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3664 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3665 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3666 _(SYN_RCVD, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3667 /* SYN-ACK for a SYN */
3668 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3670 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3671 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3672 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3674 /* ACK for for established connection -> tcp-established. */
3675 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3676 /* FIN for for established connection -> tcp-established. */
3677 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3678 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3680 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3682 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3683 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3684 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED,
3686 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3687 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3688 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3689 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3690 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3691 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3692 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3693 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3695 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3696 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3698 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3700 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3701 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3702 _(ESTABLISHED, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3703 /* ACK or FIN-ACK to our FIN */
3704 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3705 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3707 /* FIN in reply to our FIN from the other side */
3708 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3709 _(FIN_WAIT_1, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3710 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3711 _(FIN_WAIT_1, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3713 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3714 _(CLOSING, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3715 _(CLOSING, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3716 _(CLOSING, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3718 /* FIN confirming that the peer (app) has closed */
3719 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3720 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3721 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3723 _(FIN_WAIT_2, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3724 _(FIN_WAIT_2, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3726 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3727 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3729 _(CLOSE_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3730 _(CLOSE_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3732 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3733 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3734 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3736 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3737 _(LAST_ACK, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3739 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3740 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3741 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3743 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3744 _(TIME_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3746 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3747 /* RFC793 CLOSED: An incoming segment containing a RST is discarded. An
3748 * incoming segment not containing a RST causes a RST to be sent in
3750 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3751 _(CLOSED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3752 TCP_ERROR_CONNECTION_CLOSED);
3753 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3754 _(CLOSED, TCP_FLAG_SYN, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3755 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3760 static clib_error_t *
3761 tcp_input_init (vlib_main_t * vm)
3763 clib_error_t *error = 0;
3764 tcp_main_t *tm = vnet_get_tcp_main ();
3766 if ((error = vlib_call_init_function (vm, tcp_init)))
3769 /* Initialize dispatch table. */
3770 tcp_dispatch_table_init (tm);
3775 VLIB_INIT_FUNCTION (tcp_input_init);
3778 * fd.io coding-style-patch-verification: ON
3781 * eval: (c-set-style "gnu")