2 * Copyright (c) 2016-2019 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 \
83 * Validate segment sequence number. As per RFC793:
85 * Segment Receive Test
87 * ------- ------- -------------------------------------------
88 * 0 0 SEG.SEQ = RCV.NXT
89 * 0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
91 * >0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
92 * or RCV.NXT =< SEG.SEQ+SEG.LEN-1 < RCV.NXT+RCV.WND
94 * This ultimately consists in checking if segment falls within the window.
95 * The one important difference compared to RFC793 is that we use rcv_las,
96 * or the rcv_nxt at last ack sent instead of rcv_nxt since that's the
97 * peer's reference when computing our receive window.
100 * seq_leq (end_seq, tc->rcv_las + tc->rcv_wnd) && seq_geq (seq, tc->rcv_las)
101 * however, is too strict when we have retransmits. Instead we just check that
102 * the seq is not beyond the right edge and that the end of the segment is not
103 * less than the left edge.
105 * N.B. rcv_nxt and rcv_wnd are both updated in this node if acks are sent, so
106 * use rcv_nxt in the right edge window test instead of rcv_las.
110 tcp_segment_in_rcv_wnd (tcp_connection_t * tc, u32 seq, u32 end_seq)
112 return (seq_geq (end_seq, tc->rcv_las)
113 && seq_leq (seq, tc->rcv_nxt + tc->rcv_wnd));
117 * Parse TCP header options.
119 * @param th TCP header
120 * @param to TCP options data structure to be populated
121 * @param is_syn set if packet is syn
122 * @return -1 if parsing failed
125 tcp_options_parse (tcp_header_t * th, tcp_options_t * to, u8 is_syn)
128 u8 opt_len, opts_len, kind;
132 opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t);
133 data = (const u8 *) (th + 1);
135 /* Zero out all flags but those set in SYN */
136 to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE
137 | TCP_OPTS_FLAG_TSTAMP | TCP_OPTION_MSS);
139 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
143 /* Get options length */
144 if (kind == TCP_OPTION_EOL)
146 else if (kind == TCP_OPTION_NOOP)
158 /* weird option length */
159 if (opt_len < 2 || opt_len > opts_len)
169 if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
171 to->flags |= TCP_OPTS_FLAG_MSS;
172 to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
175 case TCP_OPTION_WINDOW_SCALE:
178 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
180 to->flags |= TCP_OPTS_FLAG_WSCALE;
181 to->wscale = data[2];
182 if (to->wscale > TCP_MAX_WND_SCALE)
183 to->wscale = TCP_MAX_WND_SCALE;
186 case TCP_OPTION_TIMESTAMP:
188 to->flags |= TCP_OPTS_FLAG_TSTAMP;
189 if ((to->flags & TCP_OPTS_FLAG_TSTAMP)
190 && opt_len == TCP_OPTION_LEN_TIMESTAMP)
192 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
193 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
196 case TCP_OPTION_SACK_PERMITTED:
199 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
200 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
202 case TCP_OPTION_SACK_BLOCK:
203 /* If SACK permitted was not advertised or a SYN, break */
204 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
207 /* If too short or not correctly formatted, break */
208 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
211 to->flags |= TCP_OPTS_FLAG_SACK;
212 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
213 vec_reset_length (to->sacks);
214 for (j = 0; j < to->n_sack_blocks; j++)
216 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 8 * j));
217 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 8 * j));
218 vec_add1 (to->sacks, b);
222 /* Nothing to see here */
230 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
231 * timestamp to echo and it's less than tsval_recent, drop segment
232 * but still send an ACK in order to retain TCP's mechanism for detecting
233 * and recovering from half-open connections
235 * Or at least that's what the theory says. It seems that this might not work
236 * very well with packet reordering and fast retransmit. XXX
239 tcp_segment_check_paws (tcp_connection_t * tc)
241 return tcp_opts_tstamp (&tc->rcv_opts)
242 && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent);
246 * Update tsval recent
249 tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
252 * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
253 * of an incoming segment:
254 * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
255 * then the TSval from the segment is copied to TS.Recent;
256 * otherwise, the TSval is ignored.
258 if (tcp_opts_tstamp (&tc->rcv_opts) && seq_leq (seq, tc->rcv_las)
259 && seq_leq (tc->rcv_las, seq_end))
261 ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval));
262 tc->tsval_recent = tc->rcv_opts.tsval;
263 tc->tsval_recent_age = tcp_time_now_w_thread (tc->c_thread_index);
268 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
270 * It first verifies if segment has a wrapped sequence number (PAWS) and then
271 * does the processing associated to the first four steps (ignoring security
272 * and precedence): sequence number, rst bit and syn bit checks.
274 * @return 0 if segments passes validation.
277 tcp_segment_validate (tcp_worker_ctx_t * wrk, tcp_connection_t * tc0,
278 vlib_buffer_t * b0, tcp_header_t * th0, u32 * error0)
280 /* We could get a burst of RSTs interleaved with acks */
281 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
283 tcp_send_reset (tc0);
284 *error0 = TCP_ERROR_CONNECTION_CLOSED;
288 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
290 *error0 = TCP_ERROR_SEGMENT_INVALID;
294 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts, 0)))
296 *error0 = TCP_ERROR_OPTIONS;
300 if (PREDICT_FALSE (tcp_segment_check_paws (tc0)))
302 *error0 = TCP_ERROR_PAWS;
303 TCP_EVT_DBG (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
304 vnet_buffer (b0)->tcp.seq_end);
306 /* If it just so happens that a segment updates tsval_recent for a
307 * segment over 24 days old, invalidate tsval_recent. */
308 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
309 tcp_time_now_w_thread (tc0->c_thread_index)))
311 tc0->tsval_recent = tc0->rcv_opts.tsval;
312 clib_warning ("paws failed: 24-day old segment");
314 /* Drop after ack if not rst. Resets can fail paws check as per
315 * RFC 7323 sec. 5.2: When an <RST> segment is received, it MUST NOT
316 * be subjected to the PAWS check by verifying an acceptable value in
318 else if (!tcp_rst (th0))
320 tcp_program_ack (wrk, tc0);
321 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
326 /* 1st: check sequence number */
327 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
328 vnet_buffer (b0)->tcp.seq_end))
330 /* SYN/SYN-ACK retransmit */
332 && vnet_buffer (b0)->tcp.seq_number == tc0->rcv_nxt - 1)
334 tcp_options_parse (th0, &tc0->rcv_opts, 1);
335 if (tc0->state == TCP_STATE_SYN_RCVD)
337 tcp_send_synack (tc0);
338 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0, 0);
339 *error0 = TCP_ERROR_SYNS_RCVD;
343 tcp_program_ack (wrk, tc0);
344 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, tc0);
345 *error0 = TCP_ERROR_SYN_ACKS_RCVD;
350 /* If our window is 0 and the packet is in sequence, let it pass
351 * through for ack processing. It should be dropped later. */
352 if (tc0->rcv_wnd < tc0->snd_mss
353 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number)
356 /* If we entered recovery and peer did so as well, there's a chance that
357 * dup acks won't be acceptable on either end because seq_end may be less
358 * than rcv_las. This can happen if acks are lost in both directions. */
359 if (tcp_in_recovery (tc0)
360 && seq_geq (vnet_buffer (b0)->tcp.seq_number,
361 tc0->rcv_las - tc0->rcv_wnd)
362 && seq_leq (vnet_buffer (b0)->tcp.seq_end,
363 tc0->rcv_nxt + tc0->rcv_wnd))
366 *error0 = TCP_ERROR_RCV_WND;
368 /* If not RST, send dup ack */
371 tcp_program_dupack (wrk, tc0);
372 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
380 /* 2nd: check the RST bit */
381 if (PREDICT_FALSE (tcp_rst (th0)))
383 tcp_connection_reset (tc0);
384 *error0 = TCP_ERROR_RST_RCVD;
388 /* 3rd: check security and precedence (skip) */
390 /* 4th: check the SYN bit (in window) */
391 if (PREDICT_FALSE (tcp_syn (th0)))
393 *error0 = TCP_ERROR_SPURIOUS_SYN;
394 tcp_send_reset (tc0);
398 /* If segment in window, save timestamp */
399 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
400 vnet_buffer (b0)->tcp.seq_end);
408 tcp_rcv_ack_no_cc (tcp_connection_t * tc, vlib_buffer_t * b, u32 * error)
410 /* SND.UNA =< SEG.ACK =< SND.NXT */
411 if (!(seq_leq (tc->snd_una, vnet_buffer (b)->tcp.ack_number)
412 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
414 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)
415 && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
417 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
420 *error = TCP_ERROR_ACK_INVALID;
425 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
426 tc->snd_una = vnet_buffer (b)->tcp.ack_number;
427 *error = TCP_ERROR_ACK_OK;
432 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
434 * Note that although the original article, srtt and rttvar are scaled
435 * to minimize round-off errors, here we don't. Instead, we rely on
436 * better precision time measurements.
438 * TODO support us rtt resolution
441 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
447 err = mrtt - tc->srtt;
449 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
450 * The increase should be bound */
451 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
452 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
453 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
457 /* First measurement. */
459 tc->rttvar = mrtt >> 1;
463 #ifndef CLIB_MARCH_VARIANT
465 tcp_update_rto (tcp_connection_t * tc)
467 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
468 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
470 #endif /* CLIB_MARCH_VARIANT */
473 * Update RTT estimate and RTO timer
475 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
476 * timing. Middle boxes are known to fiddle with TCP options so we
477 * should give higher priority to ACK timing.
479 * This should be called only if previously sent bytes have been acked.
481 * return 1 if valid rtt 0 otherwise
484 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
488 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
489 * RTT because they're ambiguous. */
490 if (tcp_in_cong_recovery (tc) || tc->sack_sb.sacked_bytes)
492 if (tcp_in_recovery (tc))
497 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
499 f64 sample = tcp_time_now_us (tc->c_thread_index) - tc->rtt_ts;
500 tc->mrtt_us = tc->mrtt_us + (sample - tc->mrtt_us) * 0.125;
501 mrtt = clib_max ((u32) (sample * THZ), 1);
502 /* Allow measuring of a new RTT */
505 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
506 * snd_una, i.e., the left side of the send window:
507 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
508 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
510 u32 now = tcp_time_now_w_thread (tc->c_thread_index);
511 mrtt = clib_max (now - tc->rcv_opts.tsecr, 1);
514 /* Ignore dubious measurements */
515 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
518 tcp_estimate_rtt (tc, mrtt);
522 /* If we got here something must've been ACKed so make sure boff is 0,
523 * even if mrtt is not valid since we update the rto lower */
531 tcp_estimate_initial_rtt (tcp_connection_t * tc)
533 u8 thread_index = vlib_num_workers ()? 1 : 0;
538 tc->mrtt_us = tcp_time_now_us (thread_index) - tc->rtt_ts;
539 tc->mrtt_us = clib_max (tc->mrtt_us, 0.0001);
540 mrtt = clib_max ((u32) (tc->mrtt_us * THZ), 1);
545 mrtt = tcp_time_now_w_thread (thread_index) - tc->rcv_opts.tsecr;
546 mrtt = clib_max (mrtt, 1);
547 /* Due to retransmits we don't know the initial mrtt */
548 if (tc->rto_boff && mrtt > 1 * THZ)
550 tc->mrtt_us = (f64) mrtt *TCP_TICK;
553 if (mrtt > 0 && mrtt < TCP_RTT_MAX)
554 tcp_estimate_rtt (tc, mrtt);
559 * Dequeue bytes for connections that have received acks in last burst
562 tcp_handle_postponed_dequeues (tcp_worker_ctx_t * wrk)
564 u32 thread_index = wrk->vm->thread_index;
565 u32 *pending_deq_acked;
566 tcp_connection_t *tc;
569 if (!vec_len (wrk->pending_deq_acked))
572 pending_deq_acked = wrk->pending_deq_acked;
573 for (i = 0; i < vec_len (pending_deq_acked); i++)
575 tc = tcp_connection_get (pending_deq_acked[i], thread_index);
576 tc->flags &= ~TCP_CONN_DEQ_PENDING;
578 if (PREDICT_FALSE (!tc->burst_acked))
581 /* Dequeue the newly ACKed bytes */
582 session_tx_fifo_dequeue_drop (&tc->connection, tc->burst_acked);
584 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
586 if (PREDICT_FALSE (tc->flags & TCP_CONN_PSH_PENDING))
588 if (seq_leq (tc->psh_seq, tc->snd_una))
589 tc->flags &= ~TCP_CONN_PSH_PENDING;
592 /* If everything has been acked, stop retransmit timer
593 * otherwise update. */
594 tcp_retransmit_timer_update (tc);
596 /* If not congested, update pacer based on our new
598 if (!tcp_in_fastrecovery (tc))
599 tcp_connection_tx_pacer_update (tc);
601 _vec_len (wrk->pending_deq_acked) = 0;
605 tcp_program_dequeue (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
607 if (!(tc->flags & TCP_CONN_DEQ_PENDING))
609 vec_add1 (wrk->pending_deq_acked, tc->c_c_index);
610 tc->flags |= TCP_CONN_DEQ_PENDING;
612 tc->burst_acked += tc->bytes_acked + tc->sack_sb.snd_una_adv;
616 * Check if duplicate ack as per RFC5681 Sec. 2
619 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
622 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
623 && seq_gt (tc->snd_nxt, tc->snd_una)
624 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
625 && (prev_snd_wnd == tc->snd_wnd));
629 * Checks if ack is a congestion control event.
632 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
633 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
635 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
636 * defined to be 'duplicate' */
637 *is_dack = tc->sack_sb.last_sacked_bytes
638 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
640 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
643 #ifndef CLIB_MARCH_VARIANT
645 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
647 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
648 return hole - sb->holes;
652 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
654 return hole->end - hole->start;
657 sack_scoreboard_hole_t *
658 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
660 if (index != TCP_INVALID_SACK_HOLE_INDEX)
661 return pool_elt_at_index (sb->holes, index);
665 sack_scoreboard_hole_t *
666 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
668 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
669 return pool_elt_at_index (sb->holes, hole->next);
673 sack_scoreboard_hole_t *
674 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
676 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
677 return pool_elt_at_index (sb->holes, hole->prev);
681 sack_scoreboard_hole_t *
682 scoreboard_first_hole (sack_scoreboard_t * sb)
684 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
685 return pool_elt_at_index (sb->holes, sb->head);
689 sack_scoreboard_hole_t *
690 scoreboard_last_hole (sack_scoreboard_t * sb)
692 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
693 return pool_elt_at_index (sb->holes, sb->tail);
698 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
700 sack_scoreboard_hole_t *next, *prev;
702 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
704 next = pool_elt_at_index (sb->holes, hole->next);
705 next->prev = hole->prev;
709 sb->tail = hole->prev;
712 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
714 prev = pool_elt_at_index (sb->holes, hole->prev);
715 prev->next = hole->next;
719 sb->head = hole->next;
722 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
723 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
725 /* Poison the entry */
727 clib_memset (hole, 0xfe, sizeof (*hole));
729 pool_put (sb->holes, hole);
732 static sack_scoreboard_hole_t *
733 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
736 sack_scoreboard_hole_t *hole, *next, *prev;
739 pool_get (sb->holes, hole);
740 clib_memset (hole, 0, sizeof (*hole));
744 hole_index = scoreboard_hole_index (sb, hole);
746 prev = scoreboard_get_hole (sb, prev_index);
749 hole->prev = prev_index;
750 hole->next = prev->next;
752 if ((next = scoreboard_next_hole (sb, hole)))
753 next->prev = hole_index;
755 sb->tail = hole_index;
757 prev->next = hole_index;
761 sb->head = hole_index;
762 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
763 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
768 #endif /* CLIB_MARCH_VARIANT */
770 #ifndef CLIB_MARCH_VARIANT
772 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
774 sack_scoreboard_hole_t *left, *right;
775 u32 bytes = 0, blks = 0;
778 sb->sacked_bytes = 0;
779 left = scoreboard_last_hole (sb);
783 if (seq_gt (sb->high_sacked, left->end))
785 bytes = sb->high_sacked - left->end;
789 while ((right = left)
790 && bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
791 && blks < TCP_DUPACK_THRESHOLD
792 /* left not updated if above conditions fail */
793 && (left = scoreboard_prev_hole (sb, right)))
795 bytes += right->start - left->end;
799 /* left is first lost */
804 sb->lost_bytes += scoreboard_hole_bytes (right);
806 left = scoreboard_prev_hole (sb, right);
808 bytes += right->start - left->end;
810 while ((right = left));
813 sb->sacked_bytes = bytes;
817 * Figure out the next hole to retransmit
819 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
821 sack_scoreboard_hole_t *
822 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
823 sack_scoreboard_hole_t * start,
824 u8 have_unsent, u8 * can_rescue, u8 * snd_limited)
826 sack_scoreboard_hole_t *hole = 0;
828 hole = start ? start : scoreboard_first_hole (sb);
829 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
830 hole = scoreboard_next_hole (sb, hole);
832 /* Nothing, return */
835 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
839 /* Rule (1): if higher than rxt, less than high_sacked and lost */
840 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
842 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
846 /* Rule (2): available unsent data */
849 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
852 /* Rule (3): if hole not lost */
853 else if (seq_lt (hole->start, sb->high_sacked))
856 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
858 /* Rule (4): if hole beyond high_sacked */
861 ASSERT (seq_geq (hole->start, sb->high_sacked));
864 /* HighRxt MUST NOT be updated */
869 if (hole && seq_lt (sb->high_rxt, hole->start))
870 sb->high_rxt = hole->start;
874 #endif /* CLIB_MARCH_VARIANT */
877 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 snd_una)
879 sack_scoreboard_hole_t *hole;
880 hole = scoreboard_first_hole (sb);
883 snd_una = seq_gt (snd_una, hole->start) ? snd_una : hole->start;
884 sb->cur_rxt_hole = sb->head;
886 sb->high_rxt = snd_una;
887 sb->rescue_rxt = snd_una - 1;
890 #ifndef CLIB_MARCH_VARIANT
892 scoreboard_init (sack_scoreboard_t * sb)
894 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
895 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
896 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
900 scoreboard_clear (sack_scoreboard_t * sb)
902 sack_scoreboard_hole_t *hole;
903 while ((hole = scoreboard_first_hole (sb)))
905 scoreboard_remove_hole (sb, hole);
907 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
908 ASSERT (pool_elts (sb->holes) == 0);
909 sb->sacked_bytes = 0;
910 sb->last_sacked_bytes = 0;
911 sb->last_bytes_delivered = 0;
916 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
918 #endif /* CLIB_MARCH_VARIANT */
921 * Test that scoreboard is sane after recovery
923 * Returns 1 if scoreboard is empty or if first hole beyond
927 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
929 sack_scoreboard_hole_t *hole;
930 hole = scoreboard_first_hole (&tc->sack_sb);
931 return (!hole || (seq_geq (hole->start, tc->snd_una)
932 && seq_lt (hole->end, tc->snd_nxt)));
935 #ifndef CLIB_MARCH_VARIANT
937 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
939 sack_scoreboard_t *sb = &tc->sack_sb;
940 sack_block_t *blk, tmp;
941 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
942 u32 blk_index = 0, old_sacked_bytes, hole_index;
945 sb->last_sacked_bytes = 0;
946 sb->last_bytes_delivered = 0;
949 if (!tcp_opts_sack (&tc->rcv_opts)
950 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
953 old_sacked_bytes = sb->sacked_bytes;
955 /* Remove invalid blocks */
956 blk = tc->rcv_opts.sacks;
957 while (blk < vec_end (tc->rcv_opts.sacks))
959 if (seq_lt (blk->start, blk->end)
960 && seq_gt (blk->start, tc->snd_una)
961 && seq_gt (blk->start, ack)
962 && seq_lt (blk->start, tc->snd_nxt)
963 && seq_leq (blk->end, tc->snd_nxt))
968 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
971 /* Add block for cumulative ack */
972 if (seq_gt (ack, tc->snd_una))
974 tmp.start = tc->snd_una;
976 vec_add1 (tc->rcv_opts.sacks, tmp);
979 if (vec_len (tc->rcv_opts.sacks) == 0)
982 tcp_scoreboard_trace_add (tc, ack);
984 /* Make sure blocks are ordered */
985 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
986 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
987 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
989 tmp = tc->rcv_opts.sacks[i];
990 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
991 tc->rcv_opts.sacks[j] = tmp;
994 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
996 /* If no holes, insert the first that covers all outstanding bytes */
997 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
998 tc->snd_una, tc->snd_nxt);
999 sb->tail = scoreboard_hole_index (sb, last_hole);
1000 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
1001 sb->high_sacked = tmp.end;
1005 /* If we have holes but snd_una_max is beyond the last hole, update
1007 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
1008 last_hole = scoreboard_last_hole (sb);
1009 if (seq_gt (tc->snd_nxt, last_hole->end))
1011 if (seq_geq (last_hole->start, sb->high_sacked))
1013 last_hole->end = tc->snd_nxt;
1015 /* New hole after high sacked block */
1016 else if (seq_lt (sb->high_sacked, tc->snd_nxt))
1018 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
1022 /* Keep track of max byte sacked for when the last hole
1024 if (seq_gt (tmp.end, sb->high_sacked))
1025 sb->high_sacked = tmp.end;
1028 /* Walk the holes with the SACK blocks */
1029 hole = pool_elt_at_index (sb->holes, sb->head);
1030 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
1032 blk = &tc->rcv_opts.sacks[blk_index];
1033 if (seq_leq (blk->start, hole->start))
1035 /* Block covers hole. Remove hole */
1036 if (seq_geq (blk->end, hole->end))
1038 next_hole = scoreboard_next_hole (sb, hole);
1040 /* Byte accounting: snd_una needs to be advanced */
1041 if (blk->end == ack)
1045 if (seq_lt (ack, next_hole->start))
1046 sb->snd_una_adv = next_hole->start - ack;
1047 sb->last_bytes_delivered +=
1048 next_hole->start - hole->end;
1052 ASSERT (seq_geq (sb->high_sacked, ack));
1053 sb->snd_una_adv = sb->high_sacked - ack;
1054 sb->last_bytes_delivered += sb->high_sacked - hole->end;
1058 scoreboard_remove_hole (sb, hole);
1061 /* Partial 'head' overlap */
1064 if (seq_gt (blk->end, hole->start))
1066 hole->start = blk->end;
1073 /* Hole must be split */
1074 if (seq_lt (blk->end, hole->end))
1076 hole_index = scoreboard_hole_index (sb, hole);
1077 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
1080 /* Pool might've moved */
1081 hole = scoreboard_get_hole (sb, hole_index);
1082 hole->end = blk->start;
1084 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
1086 else if (seq_lt (blk->start, hole->end))
1088 hole->end = blk->start;
1090 hole = scoreboard_next_hole (sb, hole);
1094 if (pool_elts (sb->holes) == 1)
1096 hole = scoreboard_first_hole (sb);
1097 if (hole->start == ack + sb->snd_una_adv && hole->end == tc->snd_nxt)
1098 scoreboard_remove_hole (sb, hole);
1101 scoreboard_update_bytes (tc, sb);
1102 sb->last_sacked_bytes = sb->sacked_bytes
1103 - (old_sacked_bytes - sb->last_bytes_delivered);
1104 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
1105 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
1106 || sb->sacked_bytes < tc->snd_nxt - seq_max (tc->snd_una, ack));
1107 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_nxt
1108 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1109 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1110 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
1111 TCP_EVT_DBG (TCP_EVT_CC_SCOREBOARD, tc);
1113 #endif /* CLIB_MARCH_VARIANT */
1116 * Try to update snd_wnd based on feedback received from peer.
1118 * If successful, and new window is 'effectively' 0, activate persist
1122 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1124 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1125 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1126 if (seq_lt (tc->snd_wl1, seq)
1127 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1129 tc->snd_wnd = snd_wnd;
1132 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
1134 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
1136 /* Set persist timer if not set and we just got 0 wnd */
1137 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1138 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1139 tcp_persist_timer_set (tc);
1143 tcp_persist_timer_reset (tc);
1144 if (PREDICT_FALSE (!tcp_in_recovery (tc) && tc->rto_boff > 0))
1147 tcp_update_rto (tc);
1153 #ifndef CLIB_MARCH_VARIANT
1155 * Init loss recovery/fast recovery.
1157 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1158 * updated in @ref tcp_cc_handle_event after fast retransmit
1161 tcp_cc_init_congestion (tcp_connection_t * tc)
1163 tcp_fastrecovery_on (tc);
1164 tc->snd_congestion = tc->snd_nxt;
1165 tc->cwnd_acc_bytes = 0;
1166 tc->snd_rxt_bytes = 0;
1167 tc->prev_ssthresh = tc->ssthresh;
1168 tc->prev_cwnd = tc->cwnd;
1169 tc->cc_algo->congestion (tc);
1170 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
1172 #endif /* CLIB_MARCH_VARIANT */
1175 tcp_cc_recovery_exit (tcp_connection_t * tc)
1178 tcp_update_rto (tc);
1181 tcp_recovery_off (tc);
1182 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1185 #ifndef CLIB_MARCH_VARIANT
1187 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
1189 tc->cc_algo->recovered (tc);
1190 tc->snd_rxt_bytes = 0;
1191 tc->rcv_dupacks = 0;
1192 tc->snd_rxt_bytes = 0;
1195 tcp_fastrecovery_off (tc);
1196 tcp_fastrecovery_first_off (tc);
1198 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1200 #endif /* CLIB_MARCH_VARIANT */
1203 tcp_cc_congestion_undo (tcp_connection_t * tc)
1205 tc->cwnd = tc->prev_cwnd;
1206 tc->ssthresh = tc->prev_ssthresh;
1207 tc->rcv_dupacks = 0;
1208 if (tcp_in_recovery (tc))
1210 tcp_cc_recovery_exit (tc);
1211 tc->snd_nxt = seq_max (tc->snd_nxt, tc->snd_congestion);
1213 else if (tcp_in_fastrecovery (tc))
1215 tcp_cc_fastrecovery_exit (tc);
1217 ASSERT (tc->rto_boff == 0);
1218 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
1222 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1224 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1226 && tcp_opts_tstamp (&tc->rcv_opts)
1227 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1231 tcp_cc_is_spurious_fast_rxt (tcp_connection_t * tc)
1233 return (tcp_in_fastrecovery (tc)
1234 && tc->cwnd > tc->ssthresh + 3 * tc->snd_mss);
1238 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1240 return (tcp_cc_is_spurious_timeout_rxt (tc)
1241 || tcp_cc_is_spurious_fast_rxt (tc));
1245 tcp_cc_recover (tcp_connection_t * tc)
1247 ASSERT (tcp_in_cong_recovery (tc));
1248 if (tcp_cc_is_spurious_retransmit (tc))
1250 tcp_cc_congestion_undo (tc);
1254 if (tcp_in_recovery (tc))
1255 tcp_cc_recovery_exit (tc);
1256 else if (tcp_in_fastrecovery (tc))
1257 tcp_cc_fastrecovery_exit (tc);
1259 ASSERT (tc->rto_boff == 0);
1260 ASSERT (!tcp_in_cong_recovery (tc));
1261 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1266 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
1268 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1270 /* Congestion avoidance */
1271 tcp_cc_rcv_ack (tc);
1273 /* If a cumulative ack, make sure dupacks is 0 */
1274 tc->rcv_dupacks = 0;
1276 /* When dupacks hits the threshold we only enter fast retransmit if
1277 * cumulative ack covers more than snd_congestion. Should snd_una
1278 * wrap this test may fail under otherwise valid circumstances.
1279 * Therefore, proactively update snd_congestion when wrap detected. */
1281 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1282 && seq_gt (tc->snd_congestion, tc->snd_una)))
1283 tc->snd_congestion = tc->snd_una - 1;
1287 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1289 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1293 tcp_should_fastrecover (tcp_connection_t * tc)
1295 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1296 || tcp_should_fastrecover_sack (tc));
1299 #ifndef CLIB_MARCH_VARIANT
1301 tcp_program_fastretransmit (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1303 if (!(tc->flags & TCP_CONN_FRXT_PENDING))
1305 vec_add1 (wrk->pending_fast_rxt, tc->c_c_index);
1306 tc->flags |= TCP_CONN_FRXT_PENDING;
1311 tcp_do_fastretransmits (tcp_worker_ctx_t * wrk)
1313 u32 *ongoing_fast_rxt, burst_bytes, sent_bytes, thread_index;
1314 u32 max_burst_size, burst_size, n_segs = 0, n_segs_now;
1315 tcp_connection_t *tc;
1319 if (vec_len (wrk->pending_fast_rxt) == 0
1320 && vec_len (wrk->postponed_fast_rxt) == 0)
1323 thread_index = wrk->vm->thread_index;
1324 last_cpu_time = wrk->vm->clib_time.last_cpu_time;
1325 ongoing_fast_rxt = wrk->ongoing_fast_rxt;
1326 vec_append (ongoing_fast_rxt, wrk->postponed_fast_rxt);
1327 vec_append (ongoing_fast_rxt, wrk->pending_fast_rxt);
1329 _vec_len (wrk->postponed_fast_rxt) = 0;
1330 _vec_len (wrk->pending_fast_rxt) = 0;
1332 max_burst_size = VLIB_FRAME_SIZE / vec_len (ongoing_fast_rxt);
1333 max_burst_size = clib_max (max_burst_size, 1);
1335 for (i = 0; i < vec_len (ongoing_fast_rxt); i++)
1337 tc = tcp_connection_get (ongoing_fast_rxt[i], thread_index);
1338 if (!tcp_in_fastrecovery (tc))
1340 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1344 if (n_segs >= VLIB_FRAME_SIZE)
1346 vec_add1 (wrk->postponed_fast_rxt, ongoing_fast_rxt[i]);
1350 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1351 burst_size = clib_min (max_burst_size, VLIB_FRAME_SIZE - n_segs);
1352 burst_bytes = transport_connection_tx_pacer_burst (&tc->connection,
1354 burst_size = clib_min (burst_size, burst_bytes / tc->snd_mss);
1357 tcp_program_fastretransmit (wrk, tc);
1361 n_segs_now = tcp_fast_retransmit (wrk, tc, burst_size);
1362 sent_bytes = clib_min (n_segs_now * tc->snd_mss, burst_bytes);
1363 transport_connection_tx_pacer_update_bytes (&tc->connection,
1365 n_segs += n_segs_now;
1367 _vec_len (ongoing_fast_rxt) = 0;
1368 wrk->ongoing_fast_rxt = ongoing_fast_rxt;
1370 #endif /* CLIB_MARCH_VARIANT */
1373 * One function to rule them all ... and in the darkness bind them
1376 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1380 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1382 if (tc->bytes_acked)
1384 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1388 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1389 * it account for the bytes that left the network.
1391 else if (is_dack && !tcp_in_recovery (tc))
1393 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1394 ASSERT (tc->snd_una != tc->snd_nxt || tc->sack_sb.last_sacked_bytes);
1398 /* Pure duplicate ack. If some data got acked, it's handled lower */
1399 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1401 ASSERT (tcp_in_fastrecovery (tc));
1402 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1405 else if (tcp_should_fastrecover (tc))
1409 ASSERT (!tcp_in_fastrecovery (tc));
1411 /* Heuristic to catch potential late dupacks
1412 * after fast retransmit exits */
1413 if (is_dack && tc->snd_una == tc->snd_congestion
1414 && timestamp_leq (tc->rcv_opts.tsecr, tc->tsecr_last_ack))
1416 tc->rcv_dupacks = 0;
1420 tcp_cc_init_congestion (tc);
1421 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1423 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1425 tc->cwnd = tc->ssthresh;
1426 scoreboard_init_high_rxt (&tc->sack_sb, tc->snd_una);
1430 /* Post retransmit update cwnd to ssthresh and account for the
1431 * three segments that have left the network and should've been
1432 * buffered at the receiver XXX */
1433 tc->cwnd = tc->ssthresh + 3 * tc->snd_mss;
1436 /* Constrain rate until we get a partial ack */
1437 pacer_wnd = clib_max (0.1 * tc->cwnd, 2 * tc->snd_mss);
1438 tcp_connection_tx_pacer_reset (tc, pacer_wnd,
1439 0 /* start bucket */ );
1440 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index),
1444 else if (!tc->bytes_acked
1445 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1447 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1453 /* Don't allow entry in fast recovery if still in recovery, for now */
1454 else if (0 && is_dack && tcp_in_recovery (tc))
1456 /* If of of the two conditions lower hold, reset dupacks because
1457 * we're probably after timeout (RFC6582 heuristics).
1458 * If Cumulative ack does not cover more than congestion threshold,
1460 * 1) The following doesn't hold: The congestion window is greater
1461 * than SMSS bytes and the difference between highest_ack
1462 * and prev_highest_ack is at most 4*SMSS bytes
1463 * 2) Echoed timestamp in the last non-dup ack does not equal the
1466 if (seq_leq (tc->snd_una, tc->snd_congestion)
1467 && ((!(tc->cwnd > tc->snd_mss
1468 && tc->bytes_acked <= 4 * tc->snd_mss))
1469 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1471 tc->rcv_dupacks = 0;
1476 if (!tc->bytes_acked)
1480 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1483 * Legitimate ACK. 1) See if we can exit recovery
1486 /* Update the pacing rate. For the first partial ack we move from
1487 * the artificially constrained rate to the one after congestion */
1488 tcp_connection_tx_pacer_update (tc);
1490 if (seq_geq (tc->snd_una, tc->snd_congestion))
1492 tcp_retransmit_timer_update (tc);
1494 /* If spurious return, we've already updated everything */
1495 if (tcp_cc_recover (tc))
1497 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1501 /* Treat as congestion avoidance ack */
1502 tcp_cc_rcv_ack (tc);
1507 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1510 /* XXX limit this only to first partial ack? */
1511 tcp_retransmit_timer_update (tc);
1513 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1514 * reset dupacks to 0. Also needed if in congestion recovery */
1515 tc->rcv_dupacks = 0;
1517 /* Post RTO timeout don't try anything fancy */
1518 if (tcp_in_recovery (tc))
1520 tcp_cc_rcv_ack (tc);
1521 transport_add_tx_event (&tc->connection);
1525 /* Remove retransmitted bytes that have been delivered */
1526 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1528 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1529 >= tc->sack_sb.last_bytes_delivered
1530 || (tc->flags & TCP_CONN_FINSNT));
1532 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1533 * remove sacked bytes delivered */
1534 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1536 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1537 - tc->sack_sb.last_bytes_delivered;
1538 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1539 tc->snd_rxt_bytes -= rxt_delivered;
1543 /* Apparently all retransmitted holes have been acked */
1544 tc->snd_rxt_bytes = 0;
1545 tc->sack_sb.high_rxt = tc->snd_una;
1550 tcp_fastrecovery_first_on (tc);
1551 /* Reuse last bytes delivered to track total bytes acked */
1552 tc->sack_sb.last_bytes_delivered += tc->bytes_acked;
1553 if (tc->snd_rxt_bytes > tc->bytes_acked)
1554 tc->snd_rxt_bytes -= tc->bytes_acked;
1556 tc->snd_rxt_bytes = 0;
1559 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1562 * Since this was a partial ack, try to retransmit some more data
1564 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1568 * Process incoming ACK
1571 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1572 tcp_header_t * th, u32 * error)
1574 u32 prev_snd_wnd, prev_snd_una;
1577 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1579 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1580 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1582 /* We've probably entered recovery and the peer still has some
1583 * of the data we've sent. Update snd_nxt and accept the ack */
1584 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)
1585 && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
1587 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1591 *error = TCP_ERROR_ACK_FUTURE;
1592 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1593 vnet_buffer (b)->tcp.ack_number);
1597 /* If old ACK, probably it's an old dupack */
1598 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1600 *error = TCP_ERROR_ACK_OLD;
1601 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1602 vnet_buffer (b)->tcp.ack_number);
1603 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1604 tcp_cc_handle_event (tc, 1);
1605 /* Don't drop yet */
1612 * Looks okay, process feedback
1614 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1615 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1617 prev_snd_wnd = tc->snd_wnd;
1618 prev_snd_una = tc->snd_una;
1619 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1620 vnet_buffer (b)->tcp.ack_number,
1621 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1622 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1623 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1624 tcp_validate_txf_size (tc, tc->bytes_acked);
1626 if (tc->bytes_acked)
1628 tcp_program_dequeue (wrk, tc);
1629 tcp_update_rtt (tc, vnet_buffer (b)->tcp.ack_number);
1632 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1635 * Check if we have congestion event
1638 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1640 tcp_cc_handle_event (tc, is_dack);
1641 if (!tcp_in_cong_recovery (tc))
1643 *error = TCP_ERROR_ACK_OK;
1646 *error = TCP_ERROR_ACK_DUP;
1647 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1653 * Update congestion control (slow start/congestion avoidance)
1655 tcp_cc_update (tc, b);
1656 *error = TCP_ERROR_ACK_OK;
1661 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1663 if (!tcp_disconnect_pending (tc))
1665 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1666 tcp_disconnect_pending_on (tc);
1671 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1673 u32 thread_index, *pending_disconnects;
1674 tcp_connection_t *tc;
1677 if (!vec_len (wrk->pending_disconnects))
1680 thread_index = wrk->vm->thread_index;
1681 pending_disconnects = wrk->pending_disconnects;
1682 for (i = 0; i < vec_len (pending_disconnects); i++)
1684 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1685 tcp_disconnect_pending_off (tc);
1686 session_transport_closing_notify (&tc->connection);
1688 _vec_len (wrk->pending_disconnects) = 0;
1692 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1695 /* Account for the FIN and send ack */
1697 tcp_program_ack (wrk, tc);
1698 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1699 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1700 tcp_connection_set_state (tc, TCP_STATE_CLOSE_WAIT);
1701 tcp_program_disconnect (wrk, tc);
1702 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1703 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc);
1704 *error = TCP_ERROR_FIN_RCVD;
1707 #ifndef CLIB_MARCH_VARIANT
1709 tcp_sack_vector_is_sane (sack_block_t * sacks)
1712 for (i = 1; i < vec_len (sacks); i++)
1714 if (sacks[i - 1].end == sacks[i].start)
1721 * Build SACK list as per RFC2018.
1723 * Makes sure the first block contains the segment that generated the current
1724 * ACK and the following ones are the ones most recently reported in SACK
1727 * @param tc TCP connection for which the SACK list is updated
1728 * @param start Start sequence number of the newest SACK block
1729 * @param end End sequence of the newest SACK block
1732 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1734 sack_block_t *new_list = tc->snd_sacks_fl, *block = 0;
1737 /* If the first segment is ooo add it to the list. Last write might've moved
1738 * rcv_nxt over the first segment. */
1739 if (seq_lt (tc->rcv_nxt, start))
1741 vec_add2 (new_list, block, 1);
1742 block->start = start;
1746 /* Find the blocks still worth keeping. */
1747 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1749 /* Discard if rcv_nxt advanced beyond current block */
1750 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1753 /* Merge or drop if segment overlapped by the new segment */
1754 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1755 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1757 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1758 new_list[0].start = tc->snd_sacks[i].start;
1759 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1760 new_list[0].end = tc->snd_sacks[i].end;
1764 /* Save to new SACK list if we have space. */
1765 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1766 vec_add1 (new_list, tc->snd_sacks[i]);
1769 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1771 /* Replace old vector with new one */
1772 vec_reset_length (tc->snd_sacks);
1773 tc->snd_sacks_fl = tc->snd_sacks;
1774 tc->snd_sacks = new_list;
1776 /* Segments should not 'touch' */
1777 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1781 tcp_sack_list_bytes (tcp_connection_t * tc)
1784 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1785 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1788 #endif /* CLIB_MARCH_VARIANT */
1790 /** Enqueue data for delivery to application */
1792 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1795 int written, error = TCP_ERROR_ENQUEUED;
1797 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1799 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1800 1 /* queue event */ , 1);
1802 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1804 /* Update rcv_nxt */
1805 if (PREDICT_TRUE (written == data_len))
1807 tc->rcv_nxt += written;
1809 /* If more data written than expected, account for out-of-order bytes. */
1810 else if (written > data_len)
1812 tc->rcv_nxt += written;
1813 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1815 else if (written > 0)
1817 /* We've written something but FIFO is probably full now */
1818 tc->rcv_nxt += written;
1819 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1823 return TCP_ERROR_FIFO_FULL;
1826 /* Update SACK list if need be */
1827 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1829 /* Remove SACK blocks that have been delivered */
1830 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1836 /** Enqueue out-of-order data */
1838 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1844 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1847 /* Enqueue out-of-order data with relative offset */
1848 rv = session_enqueue_stream_connection (&tc->connection, b,
1849 vnet_buffer (b)->tcp.seq_number -
1850 tc->rcv_nxt, 0 /* queue event */ ,
1853 /* Nothing written */
1856 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1857 return TCP_ERROR_FIFO_FULL;
1860 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1862 /* Update SACK list if in use */
1863 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1865 ooo_segment_t *newest;
1868 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1870 /* Get the newest segment from the fifo */
1871 newest = svm_fifo_newest_ooo_segment (s0->rx_fifo);
1874 offset = ooo_segment_offset_prod (s0->rx_fifo, newest);
1875 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1876 start = tc->rcv_nxt + offset;
1877 end = start + ooo_segment_length (s0->rx_fifo, newest);
1878 tcp_update_sack_list (tc, start, end);
1879 svm_fifo_newest_ooo_segment_reset (s0->rx_fifo);
1880 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1884 return TCP_ERROR_ENQUEUED_OOO;
1888 * Check if ACK could be delayed. If ack can be delayed, it should return
1889 * true for a full frame. If we're always acking return 0.
1892 tcp_can_delack (tcp_connection_t * tc)
1894 /* Send ack if ... */
1896 /* just sent a rcv wnd 0
1897 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0 */
1898 /* constrained to send ack */
1899 || (tc->flags & TCP_CONN_SNDACK) != 0
1900 /* we're almost out of tx wnd */
1901 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1908 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1910 u32 discard, first = b->current_length;
1911 vlib_main_t *vm = vlib_get_main ();
1913 /* Handle multi-buffer segments */
1914 if (n_bytes_to_drop > b->current_length)
1916 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1920 discard = clib_min (n_bytes_to_drop, b->current_length);
1921 vlib_buffer_advance (b, discard);
1922 b = vlib_get_buffer (vm, b->next_buffer);
1923 n_bytes_to_drop -= discard;
1925 while (n_bytes_to_drop);
1926 if (n_bytes_to_drop > first)
1927 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1930 vlib_buffer_advance (b, n_bytes_to_drop);
1931 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1936 * Receive buffer for connection and handle acks
1938 * It handles both in order or out-of-order data.
1941 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1944 u32 error, n_bytes_to_drop, n_data_bytes;
1946 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1947 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1948 ASSERT (n_data_bytes);
1950 /* Handle out-of-order data */
1951 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1953 /* Old sequence numbers allowed through because they overlapped
1955 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1957 /* Completely in the past (possible retransmit). Ack
1958 * retransmissions since we may not have any data to send */
1959 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1961 tcp_program_ack (wrk, tc);
1962 error = TCP_ERROR_SEGMENT_OLD;
1966 /* Chop off the bytes in the past and see if what is left
1967 * can be enqueued in order */
1968 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1969 n_data_bytes -= n_bytes_to_drop;
1970 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1971 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1973 error = TCP_ERROR_SEGMENT_OLD;
1979 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1980 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1981 tcp_program_dupack (wrk, tc);
1982 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1988 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1989 * segments can be enqueued after fifo tail offset changes. */
1990 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1991 if (tcp_can_delack (tc))
1993 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1994 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1998 tcp_program_ack (wrk, tc);
2006 tcp_header_t tcp_header;
2007 tcp_connection_t tcp_connection;
2011 format_tcp_rx_trace (u8 * s, va_list * args)
2013 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2014 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2015 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2016 u32 indent = format_get_indent (s);
2018 s = format (s, "%U\n%U%U",
2019 format_tcp_header, &t->tcp_header, 128,
2020 format_white_space, indent,
2021 format_tcp_connection, &t->tcp_connection, 1);
2027 format_tcp_rx_trace_short (u8 * s, va_list * args)
2029 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2030 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2031 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2033 s = format (s, "%d -> %d (%U)",
2034 clib_net_to_host_u16 (t->tcp_header.dst_port),
2035 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
2036 t->tcp_connection.state);
2042 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
2043 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
2047 clib_memcpy_fast (&t0->tcp_connection, tc0,
2048 sizeof (t0->tcp_connection));
2052 th0 = tcp_buffer_hdr (b0);
2054 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2058 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2059 vlib_frame_t * frame, u8 is_ip4)
2063 n_left = frame->n_vectors;
2064 from = vlib_frame_vector_args (frame);
2068 tcp_connection_t *tc0;
2075 b0 = vlib_get_buffer (vm, bi0);
2077 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2079 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2080 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2082 th0 = tcp_buffer_hdr (b0);
2083 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2092 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2093 u8 is_ip4, u32 evt, u32 val)
2096 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2098 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2101 #define tcp_maybe_inc_counter(node_id, err, count) \
2103 if (next0 != tcp_next_drop (is_ip4)) \
2104 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2105 tcp6_##node_id##_node.index, is_ip4, err, \
2108 #define tcp_inc_counter(node_id, err, count) \
2109 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2110 tcp6_##node_id##_node.index, is_ip4, \
2112 #define tcp_maybe_inc_err_counter(cnts, err) \
2114 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2116 #define tcp_inc_err_counter(cnts, err, val) \
2120 #define tcp_store_err_counters(node_id, cnts) \
2123 for (i = 0; i < TCP_N_ERROR; i++) \
2125 tcp_inc_counter(node_id, i, cnts[i]); \
2130 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2131 vlib_frame_t * frame, int is_ip4)
2133 u32 thread_index = vm->thread_index, errors = 0;
2134 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2135 u32 n_left_from, *from, *first_buffer;
2136 u16 err_counters[TCP_N_ERROR] = { 0 };
2138 if (node->flags & VLIB_NODE_FLAG_TRACE)
2139 tcp_established_trace_frame (vm, node, frame, is_ip4);
2141 first_buffer = from = vlib_frame_vector_args (frame);
2142 n_left_from = frame->n_vectors;
2144 while (n_left_from > 0)
2146 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2149 tcp_connection_t *tc0;
2151 if (n_left_from > 1)
2154 pb = vlib_get_buffer (vm, from[1]);
2155 vlib_prefetch_buffer_header (pb, LOAD);
2156 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2163 b0 = vlib_get_buffer (vm, bi0);
2164 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2167 if (PREDICT_FALSE (tc0 == 0))
2169 error0 = TCP_ERROR_INVALID_CONNECTION;
2173 th0 = tcp_buffer_hdr (b0);
2175 /* TODO header prediction fast path */
2177 /* 1-4: check SEQ, RST, SYN */
2178 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2180 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2184 /* 5: check the ACK field */
2185 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2188 /* 6: check the URG bit TODO */
2190 /* 7: process the segment text */
2191 if (vnet_buffer (b0)->tcp.data_len)
2192 error0 = tcp_segment_rcv (wrk, tc0, b0);
2194 /* 8: check the FIN bit */
2195 if (PREDICT_FALSE (tcp_is_fin (th0)))
2196 tcp_rcv_fin (wrk, tc0, b0, &error0);
2199 tcp_inc_err_counter (err_counters, error0, 1);
2202 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2204 err_counters[TCP_ERROR_MSG_QUEUE_FULL] = errors;
2205 tcp_store_err_counters (established, err_counters);
2206 tcp_handle_postponed_dequeues (wrk);
2207 tcp_handle_disconnects (wrk);
2208 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2210 return frame->n_vectors;
2213 VLIB_NODE_FN (tcp4_established_node) (vlib_main_t * vm,
2214 vlib_node_runtime_t * node,
2215 vlib_frame_t * from_frame)
2217 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2220 VLIB_NODE_FN (tcp6_established_node) (vlib_main_t * vm,
2221 vlib_node_runtime_t * node,
2222 vlib_frame_t * from_frame)
2224 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2228 VLIB_REGISTER_NODE (tcp4_established_node) =
2230 .name = "tcp4-established",
2231 /* Takes a vector of packets. */
2232 .vector_size = sizeof (u32),
2233 .n_errors = TCP_N_ERROR,
2234 .error_strings = tcp_error_strings,
2235 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2238 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2239 foreach_tcp_state_next
2242 .format_trace = format_tcp_rx_trace_short,
2247 VLIB_REGISTER_NODE (tcp6_established_node) =
2249 .name = "tcp6-established",
2250 /* Takes a vector of packets. */
2251 .vector_size = sizeof (u32),
2252 .n_errors = TCP_N_ERROR,
2253 .error_strings = tcp_error_strings,
2254 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2257 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2258 foreach_tcp_state_next
2261 .format_trace = format_tcp_rx_trace_short,
2267 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2269 transport_connection_t *tmp = 0;
2276 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2279 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2280 && (tc->state == TCP_STATE_LISTEN
2281 || tc->c_rmt_port == hdr->src_port));
2285 handle = session_lookup_half_open_handle (&tc->connection);
2286 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2287 tc->c_proto, tc->c_is_ip4);
2291 if (tmp->lcl_port == hdr->dst_port
2292 && tmp->rmt_port == hdr->src_port)
2294 TCP_DBG ("half-open is valid!");
2302 * Lookup transport connection
2304 static tcp_connection_t *
2305 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2309 transport_connection_t *tconn;
2310 tcp_connection_t *tc;
2315 ip4 = vlib_buffer_get_current (b);
2316 tcp = ip4_next_header (ip4);
2317 tconn = session_lookup_connection_wt4 (fib_index,
2322 TRANSPORT_PROTO_TCP,
2323 thread_index, &is_filtered);
2324 tc = tcp_get_connection_from_transport (tconn);
2325 ASSERT (tcp_lookup_is_valid (tc, tcp));
2330 ip6 = vlib_buffer_get_current (b);
2331 tcp = ip6_next_header (ip6);
2332 tconn = session_lookup_connection_wt6 (fib_index,
2337 TRANSPORT_PROTO_TCP,
2338 thread_index, &is_filtered);
2339 tc = tcp_get_connection_from_transport (tconn);
2340 ASSERT (tcp_lookup_is_valid (tc, tcp));
2346 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2347 vlib_frame_t * from_frame, int is_ip4)
2349 tcp_main_t *tm = vnet_get_tcp_main ();
2350 u32 n_left_from, *from, *first_buffer, errors = 0;
2351 u32 my_thread_index = vm->thread_index;
2352 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2354 from = first_buffer = vlib_frame_vector_args (from_frame);
2355 n_left_from = from_frame->n_vectors;
2357 while (n_left_from > 0)
2359 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2360 tcp_connection_t *tc0, *new_tc0;
2361 tcp_header_t *tcp0 = 0;
2369 b0 = vlib_get_buffer (vm, bi0);
2371 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2372 if (PREDICT_FALSE (tc0 == 0))
2374 error0 = TCP_ERROR_INVALID_CONNECTION;
2378 /* Half-open completed recently but the connection was't removed
2379 * yet by the owning thread */
2380 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2382 /* Make sure the connection actually exists */
2383 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2384 my_thread_index, is_ip4));
2385 error0 = TCP_ERROR_SPURIOUS_SYN_ACK;
2389 ack0 = vnet_buffer (b0)->tcp.ack_number;
2390 seq0 = vnet_buffer (b0)->tcp.seq_number;
2391 tcp0 = tcp_buffer_hdr (b0);
2393 /* Crude check to see if the connection handle does not match
2394 * the packet. Probably connection just switched to established */
2395 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2396 || tcp0->src_port != tc0->c_rmt_port))
2398 error0 = TCP_ERROR_INVALID_CONNECTION;
2402 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2403 && !tcp_syn (tcp0)))
2405 error0 = TCP_ERROR_SEGMENT_INVALID;
2409 /* SYNs consume sequence numbers */
2410 vnet_buffer (b0)->tcp.seq_end += tcp_is_syn (tcp0);
2413 * 1. check the ACK bit
2417 * If the ACK bit is set
2418 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2419 * the RST bit is set, if so drop the segment and return)
2420 * <SEQ=SEG.ACK><CTL=RST>
2421 * and discard the segment. Return.
2422 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2426 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2428 if (!tcp_rst (tcp0))
2429 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2430 error0 = TCP_ERROR_RCV_WND;
2434 /* Make sure ACK is valid */
2435 if (seq_gt (tc0->snd_una, ack0))
2437 error0 = TCP_ERROR_ACK_INVALID;
2443 * 2. check the RST bit
2448 /* If ACK is acceptable, signal client that peer is not
2449 * willing to accept connection and drop connection*/
2451 tcp_connection_reset (tc0);
2452 error0 = TCP_ERROR_RST_RCVD;
2457 * 3. check the security and precedence (skipped)
2461 * 4. check the SYN bit
2464 /* No SYN flag. Drop. */
2465 if (!tcp_syn (tcp0))
2467 error0 = TCP_ERROR_SEGMENT_INVALID;
2472 if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1))
2474 error0 = TCP_ERROR_OPTIONS;
2478 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2479 * current thread pool. */
2480 pool_get (tm->connections[my_thread_index], new_tc0);
2481 clib_memcpy_fast (new_tc0, tc0, sizeof (*new_tc0));
2482 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2483 new_tc0->c_thread_index = my_thread_index;
2484 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2485 new_tc0->irs = seq0;
2486 new_tc0->timers[TCP_TIMER_ESTABLISH_AO] = TCP_TIMER_HANDLE_INVALID;
2487 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2488 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2490 /* If this is not the owning thread, wait for syn retransmit to
2491 * expire and cleanup then */
2492 if (tcp_half_open_connection_cleanup (tc0))
2493 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2495 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2497 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2498 new_tc0->tsval_recent_age = tcp_time_now ();
2501 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2502 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2504 new_tc0->rcv_wscale = 0;
2506 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2507 << new_tc0->snd_wscale;
2508 new_tc0->snd_wl1 = seq0;
2509 new_tc0->snd_wl2 = ack0;
2511 tcp_connection_init_vars (new_tc0);
2513 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2514 if (PREDICT_TRUE (tcp_ack (tcp0)))
2516 /* Our SYN is ACKed: we have iss < ack = snd_una */
2518 /* TODO Dequeue acknowledged segments if we support Fast Open */
2519 new_tc0->snd_una = ack0;
2520 new_tc0->state = TCP_STATE_ESTABLISHED;
2522 /* Make sure las is initialized for the wnd computation */
2523 new_tc0->rcv_las = new_tc0->rcv_nxt;
2525 /* Notify app that we have connection. If session layer can't
2526 * allocate session send reset */
2527 if (session_stream_connect_notify (&new_tc0->connection, 0))
2529 tcp_send_reset_w_pkt (new_tc0, b0, my_thread_index, is_ip4);
2530 tcp_connection_cleanup (new_tc0);
2531 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2535 new_tc0->tx_fifo_size =
2536 transport_tx_fifo_size (&new_tc0->connection);
2537 /* Update rtt with the syn-ack sample */
2538 tcp_estimate_initial_rtt (new_tc0);
2539 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2540 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2542 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2545 new_tc0->state = TCP_STATE_SYN_RCVD;
2547 /* Notify app that we have connection */
2548 if (session_stream_connect_notify (&new_tc0->connection, 0))
2550 tcp_connection_cleanup (new_tc0);
2551 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2552 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2553 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2557 new_tc0->tx_fifo_size =
2558 transport_tx_fifo_size (&new_tc0->connection);
2559 new_tc0->rtt_ts = 0;
2560 tcp_init_snd_vars (new_tc0);
2561 tcp_send_synack (new_tc0);
2562 error0 = TCP_ERROR_SYNS_RCVD;
2566 /* Read data, if any */
2567 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2569 clib_warning ("rcvd data in syn-sent");
2570 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2571 if (error0 == TCP_ERROR_ACK_OK)
2572 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2576 tcp_program_ack (wrk, new_tc0);
2581 tcp_inc_counter (syn_sent, error0, 1);
2582 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2584 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2585 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2586 clib_memcpy_fast (&t0->tcp_connection, tc0,
2587 sizeof (t0->tcp_connection));
2591 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2593 tcp_inc_counter (syn_sent, TCP_ERROR_MSG_QUEUE_FULL, errors);
2594 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2596 return from_frame->n_vectors;
2599 VLIB_NODE_FN (tcp4_syn_sent_node) (vlib_main_t * vm,
2600 vlib_node_runtime_t * node,
2601 vlib_frame_t * from_frame)
2603 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2606 VLIB_NODE_FN (tcp6_syn_sent_node) (vlib_main_t * vm,
2607 vlib_node_runtime_t * node,
2608 vlib_frame_t * from_frame)
2610 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2614 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2616 .name = "tcp4-syn-sent",
2617 /* Takes a vector of packets. */
2618 .vector_size = sizeof (u32),
2619 .n_errors = TCP_N_ERROR,
2620 .error_strings = tcp_error_strings,
2621 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2624 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2625 foreach_tcp_state_next
2628 .format_trace = format_tcp_rx_trace_short,
2633 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2635 .name = "tcp6-syn-sent",
2636 /* Takes a vector of packets. */
2637 .vector_size = sizeof (u32),
2638 .n_errors = TCP_N_ERROR,
2639 .error_strings = tcp_error_strings,
2640 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2643 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2644 foreach_tcp_state_next
2647 .format_trace = format_tcp_rx_trace_short,
2652 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2653 * as per RFC793 p. 64
2656 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2657 vlib_frame_t * from_frame, int is_ip4)
2659 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2660 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2661 u32 n_left_from, *from, max_dequeue;
2663 from = first_buffer = vlib_frame_vector_args (from_frame);
2664 n_left_from = from_frame->n_vectors;
2666 while (n_left_from > 0)
2668 u32 bi0, error0 = TCP_ERROR_NONE;
2669 tcp_header_t *tcp0 = 0;
2670 tcp_connection_t *tc0;
2678 b0 = vlib_get_buffer (vm, bi0);
2679 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2681 if (PREDICT_FALSE (tc0 == 0))
2683 error0 = TCP_ERROR_INVALID_CONNECTION;
2687 tcp0 = tcp_buffer_hdr (b0);
2688 is_fin0 = tcp_is_fin (tcp0);
2692 tcp_connection_t *tmp;
2693 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2695 if (tmp->state != tc0->state)
2697 if (tc0->state != TCP_STATE_CLOSED)
2698 clib_warning ("state changed");
2704 * Special treatment for CLOSED
2706 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2708 error0 = TCP_ERROR_CONNECTION_CLOSED;
2713 * For all other states (except LISTEN)
2716 /* 1-4: check SEQ, RST, SYN */
2717 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2720 /* 5: check the ACK field */
2723 case TCP_STATE_SYN_RCVD:
2725 /* Make sure the segment is exactly right */
2726 if (tc0->rcv_nxt != vnet_buffer (b0)->tcp.seq_number || is_fin0)
2728 tcp_connection_reset (tc0);
2729 error0 = TCP_ERROR_SEGMENT_INVALID;
2734 * If the segment acknowledgment is not acceptable, form a
2736 * <SEQ=SEG.ACK><CTL=RST>
2739 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2741 tcp_connection_reset (tc0);
2745 /* Update rtt and rto */
2746 tcp_estimate_initial_rtt (tc0);
2748 /* Switch state to ESTABLISHED */
2749 tc0->state = TCP_STATE_ESTABLISHED;
2750 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2752 /* Initialize session variables */
2753 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2754 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2755 << tc0->rcv_opts.wscale;
2756 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2757 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2759 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2760 tcp_retransmit_timer_reset (tc0);
2761 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2762 if (session_stream_accept_notify (&tc0->connection))
2764 error0 = TCP_ERROR_MSG_QUEUE_FULL;
2765 tcp_connection_reset (tc0);
2768 error0 = TCP_ERROR_ACK_OK;
2770 case TCP_STATE_ESTABLISHED:
2771 /* We can get packets in established state here because they
2772 * were enqueued before state change */
2773 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2777 case TCP_STATE_FIN_WAIT_1:
2778 /* In addition to the processing for the ESTABLISHED state, if
2779 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2780 * continue processing in that state. */
2781 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2784 /* Still have to send the FIN */
2785 if (tc0->flags & TCP_CONN_FINPNDG)
2787 /* TX fifo finally drained */
2788 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2789 if (max_dequeue <= tc0->burst_acked)
2791 /* If a fin was received and data was acked extend wait */
2792 else if ((tc0->flags & TCP_CONN_FINRCVD) && tc0->bytes_acked)
2793 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2794 TCP_CLOSEWAIT_TIME);
2796 /* If FIN is ACKed */
2797 else if (tc0->snd_una == tc0->snd_nxt)
2799 /* Stop all retransmit timers because we have nothing more
2801 tcp_connection_timers_reset (tc0);
2803 /* We already have a FIN but didn't transition to CLOSING
2804 * because of outstanding tx data. Close the connection. */
2805 if (tc0->flags & TCP_CONN_FINRCVD)
2807 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2808 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2812 tcp_connection_set_state (tc0, TCP_STATE_FIN_WAIT_2);
2813 /* Enable waitclose because we're willing to wait for peer's
2814 * FIN but not indefinitely. */
2815 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2817 /* Don't try to deq the FIN acked */
2818 if (tc0->burst_acked > 1)
2819 session_tx_fifo_dequeue_drop (&tc0->connection,
2820 tc0->burst_acked - 1);
2821 tc0->burst_acked = 0;
2824 case TCP_STATE_FIN_WAIT_2:
2825 /* In addition to the processing for the ESTABLISHED state, if
2826 * the retransmission queue is empty, the user's CLOSE can be
2827 * acknowledged ("ok") but do not delete the TCB. */
2828 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2830 tc0->burst_acked = 0;
2832 case TCP_STATE_CLOSE_WAIT:
2833 /* Do the same processing as for the ESTABLISHED state. */
2834 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2837 if (!(tc0->flags & TCP_CONN_FINPNDG))
2840 /* Still have outstanding tx data */
2841 if (transport_max_tx_dequeue (&tc0->connection))
2845 tcp_connection_timers_reset (tc0);
2846 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2847 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2849 case TCP_STATE_CLOSING:
2850 /* In addition to the processing for the ESTABLISHED state, if
2851 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2852 * otherwise ignore the segment. */
2853 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2856 if (tc0->snd_una != tc0->snd_nxt)
2859 tcp_connection_timers_reset (tc0);
2860 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2861 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2865 case TCP_STATE_LAST_ACK:
2866 /* The only thing that [should] arrive in this state is an
2867 * acknowledgment of our FIN. If our FIN is now acknowledged,
2868 * delete the TCB, enter the CLOSED state, and return. */
2870 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2873 /* Apparently our ACK for the peer's FIN was lost */
2874 if (is_fin0 && tc0->snd_una != tc0->snd_nxt)
2880 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2882 /* Don't free the connection from the data path since
2883 * we can't ensure that we have no packets already enqueued
2884 * to output. Rely instead on the waitclose timer */
2885 tcp_connection_timers_reset (tc0);
2886 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2891 case TCP_STATE_TIME_WAIT:
2892 /* The only thing that can arrive in this state is a
2893 * retransmission of the remote FIN. Acknowledge it, and restart
2894 * the 2 MSL timeout. */
2896 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2902 tcp_program_ack (wrk, tc0);
2903 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2911 /* 6: check the URG bit TODO */
2913 /* 7: process the segment text */
2916 case TCP_STATE_ESTABLISHED:
2917 case TCP_STATE_FIN_WAIT_1:
2918 case TCP_STATE_FIN_WAIT_2:
2919 if (vnet_buffer (b0)->tcp.data_len)
2920 error0 = tcp_segment_rcv (wrk, tc0, b0);
2922 case TCP_STATE_CLOSE_WAIT:
2923 case TCP_STATE_CLOSING:
2924 case TCP_STATE_LAST_ACK:
2925 case TCP_STATE_TIME_WAIT:
2926 /* This should not occur, since a FIN has been received from the
2927 * remote side. Ignore the segment text. */
2931 /* 8: check the FIN bit */
2935 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2939 case TCP_STATE_ESTABLISHED:
2940 /* Account for the FIN and send ack */
2942 tcp_program_ack (wrk, tc0);
2943 tcp_connection_set_state (tc0, TCP_STATE_CLOSE_WAIT);
2944 tcp_program_disconnect (wrk, tc0);
2945 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
2947 case TCP_STATE_SYN_RCVD:
2948 /* Send FIN-ACK, enter LAST-ACK and because the app was not
2949 * notified yet, set a cleanup timer instead of relying on
2950 * disconnect notify and the implicit close call. */
2951 tcp_connection_timers_reset (tc0);
2954 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2955 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2957 case TCP_STATE_CLOSE_WAIT:
2958 case TCP_STATE_CLOSING:
2959 case TCP_STATE_LAST_ACK:
2962 case TCP_STATE_FIN_WAIT_1:
2965 if (tc0->flags & TCP_CONN_FINPNDG)
2967 /* If data is outstanding, stay in FIN_WAIT_1 and try to finish
2968 * sending it. Since we already received a fin, do not wait
2970 tc0->flags |= TCP_CONN_FINRCVD;
2971 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
2975 tcp_connection_set_state (tc0, TCP_STATE_CLOSING);
2976 tcp_program_ack (wrk, tc0);
2977 /* Wait for ACK for our FIN but not forever */
2978 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2981 case TCP_STATE_FIN_WAIT_2:
2982 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2984 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2985 tcp_connection_timers_reset (tc0);
2986 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2987 tcp_program_ack (wrk, tc0);
2989 case TCP_STATE_TIME_WAIT:
2990 /* Remain in the TIME-WAIT state. Restart the time-wait
2993 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2996 error0 = TCP_ERROR_FIN_RCVD;
3000 tcp_inc_counter (rcv_process, error0, 1);
3001 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3003 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3004 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
3008 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
3010 tcp_inc_counter (rcv_process, TCP_ERROR_MSG_QUEUE_FULL, errors);
3011 tcp_handle_postponed_dequeues (wrk);
3012 tcp_handle_disconnects (wrk);
3013 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3015 return from_frame->n_vectors;
3018 VLIB_NODE_FN (tcp4_rcv_process_node) (vlib_main_t * vm,
3019 vlib_node_runtime_t * node,
3020 vlib_frame_t * from_frame)
3022 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3025 VLIB_NODE_FN (tcp6_rcv_process_node) (vlib_main_t * vm,
3026 vlib_node_runtime_t * node,
3027 vlib_frame_t * from_frame)
3029 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3033 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
3035 .name = "tcp4-rcv-process",
3036 /* Takes a vector of packets. */
3037 .vector_size = sizeof (u32),
3038 .n_errors = TCP_N_ERROR,
3039 .error_strings = tcp_error_strings,
3040 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3043 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3044 foreach_tcp_state_next
3047 .format_trace = format_tcp_rx_trace_short,
3052 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
3054 .name = "tcp6-rcv-process",
3055 /* Takes a vector of packets. */
3056 .vector_size = sizeof (u32),
3057 .n_errors = TCP_N_ERROR,
3058 .error_strings = tcp_error_strings,
3059 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3062 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3063 foreach_tcp_state_next
3066 .format_trace = format_tcp_rx_trace_short,
3071 * LISTEN state processing as per RFC 793 p. 65
3074 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3075 vlib_frame_t * from_frame, int is_ip4)
3077 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3078 u32 my_thread_index = vm->thread_index;
3080 from = first_buffer = vlib_frame_vector_args (from_frame);
3081 n_left_from = from_frame->n_vectors;
3083 while (n_left_from > 0)
3088 tcp_header_t *th0 = 0;
3089 tcp_connection_t *lc0;
3092 tcp_connection_t *child0;
3093 u32 error0 = TCP_ERROR_NONE;
3099 b0 = vlib_get_buffer (vm, bi0);
3100 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3104 ip40 = vlib_buffer_get_current (b0);
3105 th0 = ip4_next_header (ip40);
3109 ip60 = vlib_buffer_get_current (b0);
3110 th0 = ip6_next_header (ip60);
3113 /* Create child session. For syn-flood protection use filter */
3115 /* 1. first check for an RST: handled in dispatch */
3116 /* if (tcp_rst (th0))
3120 /* 2. second check for an ACK: handled in dispatch */
3121 /* if (tcp_ack (th0))
3123 tcp_send_reset (b0, is_ip4);
3128 /* 3. check for a SYN (did that already) */
3130 /* Make sure connection wasn't just created */
3131 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3133 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3135 error0 = TCP_ERROR_CREATE_EXISTS;
3139 /* Create child session and send SYN-ACK */
3140 child0 = tcp_connection_alloc (my_thread_index);
3141 child0->c_lcl_port = th0->dst_port;
3142 child0->c_rmt_port = th0->src_port;
3143 child0->c_is_ip4 = is_ip4;
3144 child0->state = TCP_STATE_SYN_RCVD;
3145 child0->c_fib_index = lc0->c_fib_index;
3149 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3150 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3154 clib_memcpy_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3155 sizeof (ip6_address_t));
3156 clib_memcpy_fast (&child0->c_rmt_ip6, &ip60->src_address,
3157 sizeof (ip6_address_t));
3160 if (tcp_options_parse (th0, &child0->rcv_opts, 1))
3162 error0 = TCP_ERROR_OPTIONS;
3163 tcp_connection_free (child0);
3167 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3168 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3169 child0->rcv_las = child0->rcv_nxt;
3170 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3172 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3173 * segments are used to initialize PAWS. */
3174 if (tcp_opts_tstamp (&child0->rcv_opts))
3176 child0->tsval_recent = child0->rcv_opts.tsval;
3177 child0->tsval_recent_age = tcp_time_now ();
3180 if (tcp_opts_wscale (&child0->rcv_opts))
3181 child0->snd_wscale = child0->rcv_opts.wscale;
3183 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3184 << child0->snd_wscale;
3185 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3186 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3188 tcp_connection_init_vars (child0);
3189 child0->rto = TCP_RTO_MIN;
3191 if (session_stream_accept (&child0->connection, lc0->c_s_index,
3194 tcp_connection_cleanup (child0);
3195 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3199 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
3200 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3201 tcp_send_synack (child0);
3202 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
3206 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3208 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3209 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3210 clib_memcpy_fast (&t0->tcp_connection, lc0,
3211 sizeof (t0->tcp_connection));
3214 n_syns += (error0 == TCP_ERROR_NONE);
3217 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3218 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3220 return from_frame->n_vectors;
3223 VLIB_NODE_FN (tcp4_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3224 vlib_frame_t * from_frame)
3226 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3229 VLIB_NODE_FN (tcp6_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3230 vlib_frame_t * from_frame)
3232 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3236 VLIB_REGISTER_NODE (tcp4_listen_node) =
3238 .name = "tcp4-listen",
3239 /* Takes a vector of packets. */
3240 .vector_size = sizeof (u32),
3241 .n_errors = TCP_N_ERROR,
3242 .error_strings = tcp_error_strings,
3243 .n_next_nodes = TCP_LISTEN_N_NEXT,
3246 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3247 foreach_tcp_state_next
3250 .format_trace = format_tcp_rx_trace_short,
3255 VLIB_REGISTER_NODE (tcp6_listen_node) =
3257 .name = "tcp6-listen",
3258 /* Takes a vector of packets. */
3259 .vector_size = sizeof (u32),
3260 .n_errors = TCP_N_ERROR,
3261 .error_strings = tcp_error_strings,
3262 .n_next_nodes = TCP_LISTEN_N_NEXT,
3265 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3266 foreach_tcp_state_next
3269 .format_trace = format_tcp_rx_trace_short,
3273 typedef enum _tcp_input_next
3275 TCP_INPUT_NEXT_DROP,
3276 TCP_INPUT_NEXT_LISTEN,
3277 TCP_INPUT_NEXT_RCV_PROCESS,
3278 TCP_INPUT_NEXT_SYN_SENT,
3279 TCP_INPUT_NEXT_ESTABLISHED,
3280 TCP_INPUT_NEXT_RESET,
3281 TCP_INPUT_NEXT_PUNT,
3285 #define foreach_tcp4_input_next \
3286 _ (DROP, "ip4-drop") \
3287 _ (LISTEN, "tcp4-listen") \
3288 _ (RCV_PROCESS, "tcp4-rcv-process") \
3289 _ (SYN_SENT, "tcp4-syn-sent") \
3290 _ (ESTABLISHED, "tcp4-established") \
3291 _ (RESET, "tcp4-reset") \
3292 _ (PUNT, "ip4-punt")
3294 #define foreach_tcp6_input_next \
3295 _ (DROP, "ip6-drop") \
3296 _ (LISTEN, "tcp6-listen") \
3297 _ (RCV_PROCESS, "tcp6-rcv-process") \
3298 _ (SYN_SENT, "tcp6-syn-sent") \
3299 _ (ESTABLISHED, "tcp6-established") \
3300 _ (RESET, "tcp6-reset") \
3301 _ (PUNT, "ip6-punt")
3303 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3306 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3307 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3309 tcp_connection_t *tc;
3314 for (i = 0; i < n_bufs; i++)
3316 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3318 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3319 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3321 tcp = vlib_buffer_get_current (bs[i]);
3322 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3328 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3330 if (*error == TCP_ERROR_FILTERED || *error == TCP_ERROR_WRONG_THREAD)
3332 *next = TCP_INPUT_NEXT_DROP;
3334 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3336 *next = TCP_INPUT_NEXT_PUNT;
3337 *error = TCP_ERROR_PUNT;
3341 *next = TCP_INPUT_NEXT_RESET;
3342 *error = TCP_ERROR_NO_LISTENER;
3346 static inline tcp_connection_t *
3347 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3350 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3351 int n_advance_bytes, n_data_bytes;
3352 transport_connection_t *tc;
3358 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3359 int ip_hdr_bytes = ip4_header_bytes (ip4);
3360 if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
3362 *error = TCP_ERROR_LENGTH;
3365 tcp = ip4_next_header (ip4);
3366 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3367 n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
3368 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3370 /* Length check. Checksum computed by ipx_local no need to compute again */
3371 if (PREDICT_FALSE (n_data_bytes < 0))
3373 *error = TCP_ERROR_LENGTH;
3377 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3378 &ip4->src_address, tcp->dst_port,
3379 tcp->src_port, TRANSPORT_PROTO_TCP,
3380 thread_index, &result);
3384 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3385 if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
3387 *error = TCP_ERROR_LENGTH;
3390 tcp = ip6_next_header (ip6);
3391 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3392 n_advance_bytes = tcp_header_bytes (tcp);
3393 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3395 n_advance_bytes += sizeof (ip6[0]);
3397 if (PREDICT_FALSE (n_data_bytes < 0))
3399 *error = TCP_ERROR_LENGTH;
3403 (ip6_address_is_link_local_unicast (&ip6->dst_address)))
3405 ip4_main_t *im = &ip4_main;
3406 fib_index = vec_elt (im->fib_index_by_sw_if_index,
3407 vnet_buffer (b)->sw_if_index[VLIB_RX]);
3410 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3411 &ip6->src_address, tcp->dst_port,
3412 tcp->src_port, TRANSPORT_PROTO_TCP,
3413 thread_index, &result);
3416 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3417 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3418 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3419 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3420 vnet_buffer (b)->tcp.seq_end = vnet_buffer (b)->tcp.seq_number
3422 vnet_buffer (b)->tcp.flags = 0;
3424 *error = result ? TCP_ERROR_NONE + result : *error;
3426 return tcp_get_connection_from_transport (tc);
3430 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3431 vlib_buffer_t * b, u16 * next, u32 * error)
3436 tcp = tcp_buffer_hdr (b);
3437 flags = tcp->flags & filter_flags;
3438 *next = tm->dispatch_table[tc->state][flags].next;
3439 *error = tm->dispatch_table[tc->state][flags].error;
3441 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3442 || *next == TCP_INPUT_NEXT_RESET))
3444 /* Overload tcp flags to store state */
3445 tcp_state_t state = tc->state;
3446 vnet_buffer (b)->tcp.flags = tc->state;
3448 if (*error == TCP_ERROR_DISPATCH)
3449 clib_warning ("tcp conn %u disp error state %U flags %U",
3450 tc->c_c_index, format_tcp_state, state,
3451 format_tcp_flags, (int) flags);
3456 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3457 vlib_frame_t * frame, int is_ip4)
3459 u32 n_left_from, *from, thread_index = vm->thread_index;
3460 tcp_main_t *tm = vnet_get_tcp_main ();
3461 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3462 u16 nexts[VLIB_FRAME_SIZE], *next;
3464 tcp_set_time_now (tcp_get_worker (thread_index));
3466 from = vlib_frame_vector_args (frame);
3467 n_left_from = frame->n_vectors;
3468 vlib_get_buffers (vm, from, bufs, n_left_from);
3473 while (n_left_from >= 4)
3475 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3476 tcp_connection_t *tc0, *tc1;
3479 vlib_prefetch_buffer_header (b[2], STORE);
3480 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3482 vlib_prefetch_buffer_header (b[3], STORE);
3483 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3486 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3488 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3489 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4);
3491 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3493 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3494 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3496 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3497 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3499 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3500 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3504 if (PREDICT_TRUE (tc0 != 0))
3506 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3507 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3508 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3511 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3513 if (PREDICT_TRUE (tc1 != 0))
3515 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3516 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3517 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3520 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3527 while (n_left_from > 0)
3529 tcp_connection_t *tc0;
3530 u32 error0 = TCP_ERROR_NO_LISTENER;
3532 if (n_left_from > 1)
3534 vlib_prefetch_buffer_header (b[1], STORE);
3535 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3538 next[0] = TCP_INPUT_NEXT_DROP;
3539 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3540 if (PREDICT_TRUE (tc0 != 0))
3542 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3543 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3544 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3547 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3554 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3555 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3557 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3558 return frame->n_vectors;
3561 VLIB_NODE_FN (tcp4_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3562 vlib_frame_t * from_frame)
3564 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3567 VLIB_NODE_FN (tcp6_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3568 vlib_frame_t * from_frame)
3570 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3574 VLIB_REGISTER_NODE (tcp4_input_node) =
3576 .name = "tcp4-input",
3577 /* Takes a vector of packets. */
3578 .vector_size = sizeof (u32),
3579 .n_errors = TCP_N_ERROR,
3580 .error_strings = tcp_error_strings,
3581 .n_next_nodes = TCP_INPUT_N_NEXT,
3584 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3585 foreach_tcp4_input_next
3588 .format_buffer = format_tcp_header,
3589 .format_trace = format_tcp_rx_trace,
3594 VLIB_REGISTER_NODE (tcp6_input_node) =
3596 .name = "tcp6-input",
3597 /* Takes a vector of packets. */
3598 .vector_size = sizeof (u32),
3599 .n_errors = TCP_N_ERROR,
3600 .error_strings = tcp_error_strings,
3601 .n_next_nodes = TCP_INPUT_N_NEXT,
3604 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3605 foreach_tcp6_input_next
3608 .format_buffer = format_tcp_header,
3609 .format_trace = format_tcp_rx_trace,
3613 #ifndef CLIB_MARCH_VARIANT
3615 tcp_dispatch_table_init (tcp_main_t * tm)
3618 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3619 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3621 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3622 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3625 #define _(t,f,n,e) \
3627 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3628 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3631 /* RFC 793: In LISTEN if RST drop and if ACK return RST */
3632 _(LISTEN, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3633 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_ACK_INVALID);
3634 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_INVALID_CONNECTION);
3635 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3636 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3637 TCP_ERROR_ACK_INVALID);
3638 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3639 TCP_ERROR_SEGMENT_INVALID);
3640 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3641 TCP_ERROR_SEGMENT_INVALID);
3642 _(LISTEN, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3643 TCP_ERROR_INVALID_CONNECTION);
3644 _(LISTEN, TCP_FLAG_FIN, TCP_INPUT_NEXT_RESET, TCP_ERROR_SEGMENT_INVALID);
3645 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3646 TCP_ERROR_SEGMENT_INVALID);
3647 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3648 TCP_ERROR_SEGMENT_INVALID);
3649 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3651 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_DROP,
3652 TCP_ERROR_SEGMENT_INVALID);
3653 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3654 TCP_ERROR_SEGMENT_INVALID);
3655 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3656 TCP_ERROR_SEGMENT_INVALID);
3657 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3658 TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3659 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3660 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3661 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3662 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3664 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3665 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3667 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3669 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3670 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3671 _(SYN_RCVD, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3672 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3674 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3676 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3677 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3678 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3680 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3681 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3682 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3683 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3684 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3685 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3686 _(SYN_RCVD, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3687 /* SYN-ACK for a SYN */
3688 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3690 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3691 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3692 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3694 _(SYN_SENT, TCP_FLAG_FIN, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3695 _(SYN_SENT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3697 /* ACK for for established connection -> tcp-established. */
3698 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3699 /* FIN for for established connection -> tcp-established. */
3700 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3701 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3703 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3705 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3706 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3707 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED,
3709 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3710 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3711 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3712 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3713 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3714 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3715 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3716 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3718 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3719 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3721 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3723 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3724 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3725 _(ESTABLISHED, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3726 /* ACK or FIN-ACK to our FIN */
3727 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3728 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3730 /* FIN in reply to our FIN from the other side */
3731 _(FIN_WAIT_1, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3732 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3733 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3735 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3736 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3737 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3738 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3739 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3740 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3741 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3743 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3744 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3745 _(FIN_WAIT_1, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3746 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3748 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3750 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3751 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3752 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3753 _(FIN_WAIT_1, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3755 _(CLOSING, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3756 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3757 _(CLOSING, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3758 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3760 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3762 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3763 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3764 _(CLOSING, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3765 _(CLOSING, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3767 _(CLOSING, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3768 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3770 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3772 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3773 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3774 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3776 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3777 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3778 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3779 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3780 /* FIN confirming that the peer (app) has closed */
3781 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3782 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3783 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3785 _(FIN_WAIT_2, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3786 _(FIN_WAIT_2, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3788 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3789 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3791 _(CLOSE_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3792 _(CLOSE_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3794 _(LAST_ACK, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3795 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3796 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3797 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3799 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3801 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3802 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3803 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3805 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3806 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3807 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3808 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3809 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3810 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3811 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3812 _(LAST_ACK, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3814 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3815 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3817 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3819 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3820 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3821 _(TIME_WAIT, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3822 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3823 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3825 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3826 _(TIME_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3828 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3829 /* RFC793 CLOSED: An incoming segment containing a RST is discarded. An
3830 * incoming segment not containing a RST causes a RST to be sent in
3832 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3833 _(CLOSED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3834 TCP_ERROR_CONNECTION_CLOSED);
3835 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3836 _(CLOSED, TCP_FLAG_SYN, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3837 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3842 static clib_error_t *
3843 tcp_input_init (vlib_main_t * vm)
3845 clib_error_t *error = 0;
3846 tcp_main_t *tm = vnet_get_tcp_main ();
3848 if ((error = vlib_call_init_function (vm, tcp_init)))
3851 /* Initialize dispatch table. */
3852 tcp_dispatch_table_init (tm);
3857 VLIB_INIT_FUNCTION (tcp_input_init);
3859 #endif /* CLIB_MARCH_VARIANT */
3862 * fd.io coding-style-patch-verification: ON
3865 * eval: (c-set-style "gnu")