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 \
82 vlib_node_registration_t tcp4_established_node;
83 vlib_node_registration_t tcp6_established_node;
86 * Validate segment sequence number. As per RFC793:
88 * Segment Receive Test
90 * ------- ------- -------------------------------------------
91 * 0 0 SEG.SEQ = RCV.NXT
92 * 0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
94 * >0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
95 * or RCV.NXT =< SEG.SEQ+SEG.LEN-1 < RCV.NXT+RCV.WND
97 * This ultimately consists in checking if segment falls within the window.
98 * The one important difference compared to RFC793 is that we use rcv_las,
99 * or the rcv_nxt at last ack sent instead of rcv_nxt since that's the
100 * peer's reference when computing our receive window.
103 * seq_leq (end_seq, tc->rcv_las + tc->rcv_wnd) && seq_geq (seq, tc->rcv_las)
104 * however, is too strict when we have retransmits. Instead we just check that
105 * the seq is not beyond the right edge and that the end of the segment is not
106 * less than the left edge.
108 * N.B. rcv_nxt and rcv_wnd are both updated in this node if acks are sent, so
109 * use rcv_nxt in the right edge window test instead of rcv_las.
113 tcp_segment_in_rcv_wnd (tcp_connection_t * tc, u32 seq, u32 end_seq)
115 return (seq_geq (end_seq, tc->rcv_las)
116 && seq_leq (seq, tc->rcv_nxt + tc->rcv_wnd));
120 * Parse TCP header options.
122 * @param th TCP header
123 * @param to TCP options data structure to be populated
124 * @param is_syn set if packet is syn
125 * @return -1 if parsing failed
128 tcp_options_parse (tcp_header_t * th, tcp_options_t * to, u8 is_syn)
131 u8 opt_len, opts_len, kind;
135 opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t);
136 data = (const u8 *) (th + 1);
138 /* Zero out all flags but those set in SYN */
139 to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE
140 | TCP_OPTS_FLAG_TSTAMP | TCP_OPTION_MSS);
142 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
146 /* Get options length */
147 if (kind == TCP_OPTION_EOL)
149 else if (kind == TCP_OPTION_NOOP)
161 /* weird option length */
162 if (opt_len < 2 || opt_len > opts_len)
172 if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
174 to->flags |= TCP_OPTS_FLAG_MSS;
175 to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
178 case TCP_OPTION_WINDOW_SCALE:
181 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
183 to->flags |= TCP_OPTS_FLAG_WSCALE;
184 to->wscale = data[2];
185 if (to->wscale > TCP_MAX_WND_SCALE)
186 to->wscale = TCP_MAX_WND_SCALE;
189 case TCP_OPTION_TIMESTAMP:
191 to->flags |= TCP_OPTS_FLAG_TSTAMP;
192 if ((to->flags & TCP_OPTS_FLAG_TSTAMP)
193 && opt_len == TCP_OPTION_LEN_TIMESTAMP)
195 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
196 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
199 case TCP_OPTION_SACK_PERMITTED:
202 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
203 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
205 case TCP_OPTION_SACK_BLOCK:
206 /* If SACK permitted was not advertised or a SYN, break */
207 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
210 /* If too short or not correctly formatted, break */
211 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
214 to->flags |= TCP_OPTS_FLAG_SACK;
215 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
216 vec_reset_length (to->sacks);
217 for (j = 0; j < to->n_sack_blocks; j++)
219 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 8 * j));
220 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 8 * j));
221 vec_add1 (to->sacks, b);
225 /* Nothing to see here */
233 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
234 * timestamp to echo and it's less than tsval_recent, drop segment
235 * but still send an ACK in order to retain TCP's mechanism for detecting
236 * and recovering from half-open connections
238 * Or at least that's what the theory says. It seems that this might not work
239 * very well with packet reordering and fast retransmit. XXX
242 tcp_segment_check_paws (tcp_connection_t * tc)
244 return tcp_opts_tstamp (&tc->rcv_opts)
245 && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent);
249 * Update tsval recent
252 tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
255 * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
256 * of an incoming segment:
257 * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
258 * then the TSval from the segment is copied to TS.Recent;
259 * otherwise, the TSval is ignored.
261 if (tcp_opts_tstamp (&tc->rcv_opts) && seq_leq (seq, tc->rcv_las)
262 && seq_leq (tc->rcv_las, seq_end))
264 ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval));
265 tc->tsval_recent = tc->rcv_opts.tsval;
266 tc->tsval_recent_age = tcp_time_now_w_thread (tc->c_thread_index);
271 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
273 * It first verifies if segment has a wrapped sequence number (PAWS) and then
274 * does the processing associated to the first four steps (ignoring security
275 * and precedence): sequence number, rst bit and syn bit checks.
277 * @return 0 if segments passes validation.
280 tcp_segment_validate (tcp_worker_ctx_t * wrk, tcp_connection_t * tc0,
281 vlib_buffer_t * b0, tcp_header_t * th0, u32 * error0)
283 /* We could get a burst of RSTs interleaved with acks */
284 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
286 tcp_send_reset (tc0);
287 *error0 = TCP_ERROR_CONNECTION_CLOSED;
291 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
293 *error0 = TCP_ERROR_SEGMENT_INVALID;
297 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts, 0)))
299 *error0 = TCP_ERROR_OPTIONS;
303 if (PREDICT_FALSE (tcp_segment_check_paws (tc0)))
305 *error0 = TCP_ERROR_PAWS;
306 TCP_EVT_DBG (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
307 vnet_buffer (b0)->tcp.seq_end);
309 /* If it just so happens that a segment updates tsval_recent for a
310 * segment over 24 days old, invalidate tsval_recent. */
311 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
312 tcp_time_now_w_thread (tc0->c_thread_index)))
314 tc0->tsval_recent = tc0->rcv_opts.tsval;
315 clib_warning ("paws failed: 24-day old segment");
317 /* Drop after ack if not rst. Resets can fail paws check as per
318 * RFC 7323 sec. 5.2: When an <RST> segment is received, it MUST NOT
319 * be subjected to the PAWS check by verifying an acceptable value in
321 else if (!tcp_rst (th0))
323 tcp_program_ack (wrk, tc0);
324 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
329 /* 1st: check sequence number */
330 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
331 vnet_buffer (b0)->tcp.seq_end))
333 /* SYN/SYN-ACK retransmit */
335 && vnet_buffer (b0)->tcp.seq_number == tc0->rcv_nxt - 1)
337 tcp_options_parse (th0, &tc0->rcv_opts, 1);
338 if (tc0->state == TCP_STATE_SYN_RCVD)
340 tcp_send_synack (tc0);
341 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0, 0);
342 *error0 = TCP_ERROR_SYNS_RCVD;
346 tcp_program_ack (wrk, tc0);
347 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, tc0);
348 *error0 = TCP_ERROR_SYN_ACKS_RCVD;
353 /* If our window is 0 and the packet is in sequence, let it pass
354 * through for ack processing. It should be dropped later. */
355 if (tc0->rcv_wnd == 0
356 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number)
359 /* If we entered recovery and peer did so as well, there's a chance that
360 * dup acks won't be acceptable on either end because seq_end may be less
361 * than rcv_las. This can happen if acks are lost in both directions. */
362 if (tcp_in_recovery (tc0)
363 && seq_geq (vnet_buffer (b0)->tcp.seq_number,
364 tc0->rcv_las - tc0->rcv_wnd)
365 && seq_leq (vnet_buffer (b0)->tcp.seq_end,
366 tc0->rcv_nxt + tc0->rcv_wnd))
369 *error0 = TCP_ERROR_RCV_WND;
371 /* If not RST, send dup ack */
374 tcp_program_dupack (wrk, tc0);
375 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
383 /* 2nd: check the RST bit */
384 if (PREDICT_FALSE (tcp_rst (th0)))
386 tcp_connection_reset (tc0);
387 *error0 = TCP_ERROR_RST_RCVD;
391 /* 3rd: check security and precedence (skip) */
393 /* 4th: check the SYN bit (in window) */
394 if (PREDICT_FALSE (tcp_syn (th0)))
396 *error0 = TCP_ERROR_SPURIOUS_SYN;
397 tcp_send_reset (tc0);
401 /* If segment in window, save timestamp */
402 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
403 vnet_buffer (b0)->tcp.seq_end);
411 tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0)
413 /* SND.UNA =< SEG.ACK =< SND.NXT */
414 return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number)
415 && seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt));
419 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
421 * Note that although the original article, srtt and rttvar are scaled
422 * to minimize round-off errors, here we don't. Instead, we rely on
423 * better precision time measurements.
425 * TODO support us rtt resolution
428 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
434 err = mrtt - tc->srtt;
436 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
437 * The increase should be bound */
438 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
439 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
440 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
444 /* First measurement. */
446 tc->rttvar = mrtt >> 1;
451 tcp_update_rto (tcp_connection_t * tc)
453 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
454 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
458 * Update RTT estimate and RTO timer
460 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
461 * timing. Middle boxes are known to fiddle with TCP options so we
462 * should give higher priority to ACK timing.
464 * This should be called only if previously sent bytes have been acked.
466 * return 1 if valid rtt 0 otherwise
469 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
473 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
474 * RTT because they're ambiguous. */
475 if (tcp_in_cong_recovery (tc) || tc->sack_sb.sacked_bytes)
477 if (tcp_in_recovery (tc))
482 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
484 f64 sample = tcp_time_now_us (tc->c_thread_index) - tc->rtt_ts;
485 tc->mrtt_us = tc->mrtt_us + (sample - tc->mrtt_us) * 0.125;
486 mrtt = clib_max ((u32) (sample * THZ), 1);
487 /* Allow measuring of a new RTT */
490 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
491 * snd_una, i.e., the left side of the send window:
492 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
493 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
495 u32 now = tcp_time_now_w_thread (tc->c_thread_index);
496 mrtt = clib_max (now - tc->rcv_opts.tsecr, 1);
499 /* Ignore dubious measurements */
500 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
503 tcp_estimate_rtt (tc, mrtt);
507 /* If we got here something must've been ACKed so make sure boff is 0,
508 * even if mrtt is not valid since we update the rto lower */
516 tcp_estimate_initial_rtt (tcp_connection_t * tc)
518 u8 thread_index = vlib_num_workers ()? 1 : 0;
523 tc->mrtt_us = tcp_time_now_us (thread_index) - tc->rtt_ts;
524 tc->mrtt_us = clib_max (tc->mrtt_us, 0.0001);
525 mrtt = clib_max ((u32) (tc->mrtt_us * THZ), 1);
530 mrtt = tcp_time_now_w_thread (thread_index) - tc->rcv_opts.tsecr;
531 mrtt = clib_max (mrtt, 1);
532 /* Due to retransmits we don't know the initial mrtt */
533 if (tc->rto_boff && mrtt > 1 * THZ)
535 tc->mrtt_us = (f64) mrtt *TCP_TICK;
538 if (mrtt > 0 && mrtt < TCP_RTT_MAX)
539 tcp_estimate_rtt (tc, mrtt);
544 * Dequeue bytes for connections that have received acks in last burst
547 tcp_handle_postponed_dequeues (tcp_worker_ctx_t * wrk)
549 u32 thread_index = wrk->vm->thread_index;
550 u32 *pending_deq_acked;
551 tcp_connection_t *tc;
554 if (!vec_len (wrk->pending_deq_acked))
557 pending_deq_acked = wrk->pending_deq_acked;
558 for (i = 0; i < vec_len (pending_deq_acked); i++)
560 tc = tcp_connection_get (pending_deq_acked[i], thread_index);
561 tc->flags &= ~TCP_CONN_DEQ_PENDING;
563 if (PREDICT_FALSE (!tc->burst_acked))
566 /* Dequeue the newly ACKed bytes */
567 stream_session_dequeue_drop (&tc->connection, tc->burst_acked);
569 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
571 if (PREDICT_FALSE (tc->flags & TCP_CONN_PSH_PENDING))
573 if (seq_leq (tc->psh_seq, tc->snd_una))
574 tc->flags &= ~TCP_CONN_PSH_PENDING;
577 /* If everything has been acked, stop retransmit timer
578 * otherwise update. */
579 tcp_retransmit_timer_update (tc);
581 /* If not congested, update pacer based on our new
583 if (!tcp_in_fastrecovery (tc))
584 tcp_connection_tx_pacer_update (tc);
586 _vec_len (wrk->pending_deq_acked) = 0;
590 tcp_program_dequeue (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
592 if (!(tc->flags & TCP_CONN_DEQ_PENDING))
594 vec_add1 (wrk->pending_deq_acked, tc->c_c_index);
595 tc->flags |= TCP_CONN_DEQ_PENDING;
597 tc->burst_acked += tc->bytes_acked + tc->sack_sb.snd_una_adv;
601 * Check if duplicate ack as per RFC5681 Sec. 2
604 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
607 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
608 && seq_gt (tc->snd_una_max, tc->snd_una)
609 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
610 && (prev_snd_wnd == tc->snd_wnd));
614 * Checks if ack is a congestion control event.
617 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
618 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
620 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
621 * defined to be 'duplicate' */
622 *is_dack = tc->sack_sb.last_sacked_bytes
623 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
625 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
629 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
631 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
632 return hole - sb->holes;
636 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
638 return hole->end - hole->start;
641 sack_scoreboard_hole_t *
642 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
644 if (index != TCP_INVALID_SACK_HOLE_INDEX)
645 return pool_elt_at_index (sb->holes, index);
649 sack_scoreboard_hole_t *
650 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
652 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
653 return pool_elt_at_index (sb->holes, hole->next);
657 sack_scoreboard_hole_t *
658 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
660 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
661 return pool_elt_at_index (sb->holes, hole->prev);
665 sack_scoreboard_hole_t *
666 scoreboard_first_hole (sack_scoreboard_t * sb)
668 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
669 return pool_elt_at_index (sb->holes, sb->head);
673 sack_scoreboard_hole_t *
674 scoreboard_last_hole (sack_scoreboard_t * sb)
676 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
677 return pool_elt_at_index (sb->holes, sb->tail);
682 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
684 sack_scoreboard_hole_t *next, *prev;
686 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
688 next = pool_elt_at_index (sb->holes, hole->next);
689 next->prev = hole->prev;
693 sb->tail = hole->prev;
696 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
698 prev = pool_elt_at_index (sb->holes, hole->prev);
699 prev->next = hole->next;
703 sb->head = hole->next;
706 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
707 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
709 /* Poison the entry */
711 clib_memset (hole, 0xfe, sizeof (*hole));
713 pool_put (sb->holes, hole);
716 static sack_scoreboard_hole_t *
717 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
720 sack_scoreboard_hole_t *hole, *next, *prev;
723 pool_get (sb->holes, hole);
724 clib_memset (hole, 0, sizeof (*hole));
728 hole_index = scoreboard_hole_index (sb, hole);
730 prev = scoreboard_get_hole (sb, prev_index);
733 hole->prev = prev_index;
734 hole->next = prev->next;
736 if ((next = scoreboard_next_hole (sb, hole)))
737 next->prev = hole_index;
739 sb->tail = hole_index;
741 prev->next = hole_index;
745 sb->head = hole_index;
746 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
747 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
754 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
756 sack_scoreboard_hole_t *left, *right;
757 u32 bytes = 0, blks = 0;
760 sb->sacked_bytes = 0;
761 left = scoreboard_last_hole (sb);
765 if (seq_gt (sb->high_sacked, left->end))
767 bytes = sb->high_sacked - left->end;
771 while ((right = left)
772 && bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
773 && blks < TCP_DUPACK_THRESHOLD
774 /* left not updated if above conditions fail */
775 && (left = scoreboard_prev_hole (sb, right)))
777 bytes += right->start - left->end;
781 /* left is first lost */
786 sb->lost_bytes += scoreboard_hole_bytes (right);
788 left = scoreboard_prev_hole (sb, right);
790 bytes += right->start - left->end;
792 while ((right = left));
795 sb->sacked_bytes = bytes;
799 * Figure out the next hole to retransmit
801 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
803 sack_scoreboard_hole_t *
804 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
805 sack_scoreboard_hole_t * start,
806 u8 have_unsent, u8 * can_rescue, u8 * snd_limited)
808 sack_scoreboard_hole_t *hole = 0;
810 hole = start ? start : scoreboard_first_hole (sb);
811 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
812 hole = scoreboard_next_hole (sb, hole);
814 /* Nothing, return */
817 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
821 /* Rule (1): if higher than rxt, less than high_sacked and lost */
822 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
824 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
828 /* Rule (2): available unsent data */
831 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
834 /* Rule (3): if hole not lost */
835 else if (seq_lt (hole->start, sb->high_sacked))
838 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
840 /* Rule (4): if hole beyond high_sacked */
843 ASSERT (seq_geq (hole->start, sb->high_sacked));
846 /* HighRxt MUST NOT be updated */
851 if (hole && seq_lt (sb->high_rxt, hole->start))
852 sb->high_rxt = hole->start;
858 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 snd_una)
860 sack_scoreboard_hole_t *hole;
861 hole = scoreboard_first_hole (sb);
864 snd_una = seq_gt (snd_una, hole->start) ? snd_una : hole->start;
865 sb->cur_rxt_hole = sb->head;
867 sb->high_rxt = snd_una;
868 sb->rescue_rxt = snd_una - 1;
872 scoreboard_init (sack_scoreboard_t * sb)
874 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
875 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
876 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
880 scoreboard_clear (sack_scoreboard_t * sb)
882 sack_scoreboard_hole_t *hole;
883 while ((hole = scoreboard_first_hole (sb)))
885 scoreboard_remove_hole (sb, hole);
887 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
888 ASSERT (pool_elts (sb->holes) == 0);
889 sb->sacked_bytes = 0;
890 sb->last_sacked_bytes = 0;
891 sb->last_bytes_delivered = 0;
896 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
900 * Test that scoreboard is sane after recovery
902 * Returns 1 if scoreboard is empty or if first hole beyond
906 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
908 sack_scoreboard_hole_t *hole;
909 hole = scoreboard_first_hole (&tc->sack_sb);
910 return (!hole || (seq_geq (hole->start, tc->snd_una)
911 && seq_lt (hole->end, tc->snd_una_max)));
915 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
917 sack_scoreboard_t *sb = &tc->sack_sb;
918 sack_block_t *blk, tmp;
919 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
920 u32 blk_index = 0, old_sacked_bytes, hole_index;
923 sb->last_sacked_bytes = 0;
924 sb->last_bytes_delivered = 0;
927 if (!tcp_opts_sack (&tc->rcv_opts)
928 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
931 old_sacked_bytes = sb->sacked_bytes;
933 /* Remove invalid blocks */
934 blk = tc->rcv_opts.sacks;
935 while (blk < vec_end (tc->rcv_opts.sacks))
937 if (seq_lt (blk->start, blk->end)
938 && seq_gt (blk->start, tc->snd_una)
939 && seq_gt (blk->start, ack)
940 && seq_lt (blk->start, tc->snd_una_max)
941 && seq_leq (blk->end, tc->snd_una_max))
946 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
949 /* Add block for cumulative ack */
950 if (seq_gt (ack, tc->snd_una))
952 tmp.start = tc->snd_una;
954 vec_add1 (tc->rcv_opts.sacks, tmp);
957 if (vec_len (tc->rcv_opts.sacks) == 0)
960 tcp_scoreboard_trace_add (tc, ack);
962 /* Make sure blocks are ordered */
963 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
964 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
965 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
967 tmp = tc->rcv_opts.sacks[i];
968 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
969 tc->rcv_opts.sacks[j] = tmp;
972 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
974 /* If no holes, insert the first that covers all outstanding bytes */
975 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
976 tc->snd_una, tc->snd_una_max);
977 sb->tail = scoreboard_hole_index (sb, last_hole);
978 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
979 sb->high_sacked = tmp.end;
983 /* If we have holes but snd_una_max is beyond the last hole, update
985 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
986 last_hole = scoreboard_last_hole (sb);
987 if (seq_gt (tc->snd_una_max, last_hole->end))
989 if (seq_geq (last_hole->start, sb->high_sacked))
991 last_hole->end = tc->snd_una_max;
993 /* New hole after high sacked block */
994 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
996 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
1000 /* Keep track of max byte sacked for when the last hole
1002 if (seq_gt (tmp.end, sb->high_sacked))
1003 sb->high_sacked = tmp.end;
1006 /* Walk the holes with the SACK blocks */
1007 hole = pool_elt_at_index (sb->holes, sb->head);
1008 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
1010 blk = &tc->rcv_opts.sacks[blk_index];
1011 if (seq_leq (blk->start, hole->start))
1013 /* Block covers hole. Remove hole */
1014 if (seq_geq (blk->end, hole->end))
1016 next_hole = scoreboard_next_hole (sb, hole);
1018 /* Byte accounting: snd_una needs to be advanced */
1019 if (blk->end == ack)
1023 if (seq_lt (ack, next_hole->start))
1024 sb->snd_una_adv = next_hole->start - ack;
1025 sb->last_bytes_delivered +=
1026 next_hole->start - hole->end;
1030 ASSERT (seq_geq (sb->high_sacked, ack));
1031 sb->snd_una_adv = sb->high_sacked - ack;
1032 sb->last_bytes_delivered += sb->high_sacked - hole->end;
1036 scoreboard_remove_hole (sb, hole);
1039 /* Partial 'head' overlap */
1042 if (seq_gt (blk->end, hole->start))
1044 hole->start = blk->end;
1051 /* Hole must be split */
1052 if (seq_lt (blk->end, hole->end))
1054 hole_index = scoreboard_hole_index (sb, hole);
1055 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
1058 /* Pool might've moved */
1059 hole = scoreboard_get_hole (sb, hole_index);
1060 hole->end = blk->start;
1062 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
1064 else if (seq_lt (blk->start, hole->end))
1066 hole->end = blk->start;
1068 hole = scoreboard_next_hole (sb, hole);
1072 if (pool_elts (sb->holes) == 1)
1074 hole = scoreboard_first_hole (sb);
1075 if (hole->start == ack + sb->snd_una_adv
1076 && hole->end == tc->snd_una_max)
1077 scoreboard_remove_hole (sb, hole);
1080 scoreboard_update_bytes (tc, sb);
1081 sb->last_sacked_bytes = sb->sacked_bytes
1082 - (old_sacked_bytes - sb->last_bytes_delivered);
1083 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
1084 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
1085 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
1086 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
1087 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1088 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1089 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
1090 TCP_EVT_DBG (TCP_EVT_CC_SCOREBOARD, tc);
1094 * Try to update snd_wnd based on feedback received from peer.
1096 * If successful, and new window is 'effectively' 0, activate persist
1100 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1102 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1103 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1104 if (seq_lt (tc->snd_wl1, seq)
1105 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1107 tc->snd_wnd = snd_wnd;
1110 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
1112 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
1114 /* Set persist timer if not set and we just got 0 wnd */
1115 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1116 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1117 tcp_persist_timer_set (tc);
1121 tcp_persist_timer_reset (tc);
1122 if (PREDICT_FALSE (!tcp_in_recovery (tc) && tc->rto_boff > 0))
1125 tcp_update_rto (tc);
1132 * Init loss recovery/fast recovery.
1134 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1135 * updated in @ref tcp_cc_handle_event after fast retransmit
1138 tcp_cc_init_congestion (tcp_connection_t * tc)
1140 tcp_fastrecovery_on (tc);
1141 tc->snd_congestion = tc->snd_una_max;
1142 tc->cwnd_acc_bytes = 0;
1143 tc->snd_rxt_bytes = 0;
1144 tc->prev_ssthresh = tc->ssthresh;
1145 tc->prev_cwnd = tc->cwnd;
1146 tc->cc_algo->congestion (tc);
1147 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
1151 tcp_cc_recovery_exit (tcp_connection_t * tc)
1154 tcp_update_rto (tc);
1156 tc->snd_nxt = tc->snd_una_max;
1158 tcp_recovery_off (tc);
1159 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1163 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
1165 tc->cc_algo->recovered (tc);
1166 tc->snd_rxt_bytes = 0;
1167 tc->rcv_dupacks = 0;
1168 tc->snd_nxt = tc->snd_una_max;
1169 tc->snd_rxt_bytes = 0;
1172 tcp_fastrecovery_off (tc);
1173 tcp_fastrecovery_first_off (tc);
1175 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1179 tcp_cc_congestion_undo (tcp_connection_t * tc)
1181 tc->cwnd = tc->prev_cwnd;
1182 tc->ssthresh = tc->prev_ssthresh;
1183 tc->snd_nxt = tc->snd_una_max;
1184 tc->rcv_dupacks = 0;
1185 if (tcp_in_recovery (tc))
1186 tcp_cc_recovery_exit (tc);
1187 else if (tcp_in_fastrecovery (tc))
1188 tcp_cc_fastrecovery_exit (tc);
1189 ASSERT (tc->rto_boff == 0);
1190 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
1194 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1196 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1198 && tcp_opts_tstamp (&tc->rcv_opts)
1199 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1203 tcp_cc_is_spurious_fast_rxt (tcp_connection_t * tc)
1205 return (tcp_in_fastrecovery (tc)
1206 && tc->cwnd > tc->ssthresh + 3 * tc->snd_mss);
1210 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1212 return (tcp_cc_is_spurious_timeout_rxt (tc)
1213 || tcp_cc_is_spurious_fast_rxt (tc));
1217 tcp_cc_recover (tcp_connection_t * tc)
1219 ASSERT (tcp_in_cong_recovery (tc));
1220 if (tcp_cc_is_spurious_retransmit (tc))
1222 tcp_cc_congestion_undo (tc);
1226 if (tcp_in_recovery (tc))
1227 tcp_cc_recovery_exit (tc);
1228 else if (tcp_in_fastrecovery (tc))
1229 tcp_cc_fastrecovery_exit (tc);
1231 ASSERT (tc->rto_boff == 0);
1232 ASSERT (!tcp_in_cong_recovery (tc));
1233 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1238 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
1240 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1242 /* Congestion avoidance */
1243 tcp_cc_rcv_ack (tc);
1245 /* If a cumulative ack, make sure dupacks is 0 */
1246 tc->rcv_dupacks = 0;
1248 /* When dupacks hits the threshold we only enter fast retransmit if
1249 * cumulative ack covers more than snd_congestion. Should snd_una
1250 * wrap this test may fail under otherwise valid circumstances.
1251 * Therefore, proactively update snd_congestion when wrap detected. */
1253 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1254 && seq_gt (tc->snd_congestion, tc->snd_una)))
1255 tc->snd_congestion = tc->snd_una - 1;
1259 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1261 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1265 tcp_should_fastrecover (tcp_connection_t * tc)
1267 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1268 || tcp_should_fastrecover_sack (tc));
1272 tcp_program_fastretransmit (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1274 if (!(tc->flags & TCP_CONN_FRXT_PENDING))
1276 vec_add1 (wrk->pending_fast_rxt, tc->c_c_index);
1277 tc->flags |= TCP_CONN_FRXT_PENDING;
1282 tcp_do_fastretransmits (tcp_worker_ctx_t * wrk)
1284 u32 *ongoing_fast_rxt, burst_bytes, sent_bytes, thread_index;
1285 u32 max_burst_size, burst_size, n_segs = 0, n_segs_now;
1286 tcp_connection_t *tc;
1290 if (vec_len (wrk->pending_fast_rxt) == 0
1291 && vec_len (wrk->postponed_fast_rxt) == 0)
1294 thread_index = wrk->vm->thread_index;
1295 last_cpu_time = wrk->vm->clib_time.last_cpu_time;
1296 ongoing_fast_rxt = wrk->ongoing_fast_rxt;
1297 vec_append (ongoing_fast_rxt, wrk->postponed_fast_rxt);
1298 vec_append (ongoing_fast_rxt, wrk->pending_fast_rxt);
1300 _vec_len (wrk->postponed_fast_rxt) = 0;
1301 _vec_len (wrk->pending_fast_rxt) = 0;
1303 max_burst_size = VLIB_FRAME_SIZE / vec_len (ongoing_fast_rxt);
1304 max_burst_size = clib_max (max_burst_size, 1);
1306 for (i = 0; i < vec_len (ongoing_fast_rxt); i++)
1308 if (n_segs >= VLIB_FRAME_SIZE)
1310 vec_add1 (wrk->postponed_fast_rxt, ongoing_fast_rxt[i]);
1314 tc = tcp_connection_get (ongoing_fast_rxt[i], thread_index);
1315 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1317 if (!tcp_in_fastrecovery (tc))
1320 burst_size = clib_min (max_burst_size, VLIB_FRAME_SIZE - n_segs);
1321 burst_bytes = transport_connection_tx_pacer_burst (&tc->connection,
1323 burst_size = clib_min (burst_size, burst_bytes / tc->snd_mss);
1326 tcp_program_fastretransmit (wrk, tc);
1330 n_segs_now = tcp_fast_retransmit (wrk, tc, burst_size);
1331 sent_bytes = clib_min (n_segs_now * tc->snd_mss, burst_bytes);
1332 transport_connection_tx_pacer_update_bytes (&tc->connection,
1334 n_segs += n_segs_now;
1336 _vec_len (ongoing_fast_rxt) = 0;
1337 wrk->ongoing_fast_rxt = ongoing_fast_rxt;
1341 * One function to rule them all ... and in the darkness bind them
1344 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1348 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1350 if (tc->bytes_acked)
1352 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1356 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1357 * it account for the bytes that left the network.
1359 else if (is_dack && !tcp_in_recovery (tc))
1361 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1362 ASSERT (tc->snd_una != tc->snd_una_max
1363 || tc->sack_sb.last_sacked_bytes);
1367 /* Pure duplicate ack. If some data got acked, it's handled lower */
1368 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1370 ASSERT (tcp_in_fastrecovery (tc));
1371 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1374 else if (tcp_should_fastrecover (tc))
1378 ASSERT (!tcp_in_fastrecovery (tc));
1380 /* Heuristic to catch potential late dupacks
1381 * after fast retransmit exits */
1382 if (is_dack && tc->snd_una == tc->snd_congestion
1383 && timestamp_leq (tc->rcv_opts.tsecr, tc->tsecr_last_ack))
1385 tc->rcv_dupacks = 0;
1389 tcp_cc_init_congestion (tc);
1390 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1392 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1394 tc->cwnd = tc->ssthresh;
1395 scoreboard_init_high_rxt (&tc->sack_sb, tc->snd_una);
1399 /* Post retransmit update cwnd to ssthresh and account for the
1400 * three segments that have left the network and should've been
1401 * buffered at the receiver XXX */
1402 tc->cwnd = tc->ssthresh + 3 * tc->snd_mss;
1405 /* Constrain rate until we get a partial ack */
1406 pacer_wnd = clib_max (0.1 * tc->cwnd, 2 * tc->snd_mss);
1407 tcp_connection_tx_pacer_reset (tc, pacer_wnd,
1408 0 /* start bucket */ );
1409 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index),
1413 else if (!tc->bytes_acked
1414 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1416 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1422 /* Don't allow entry in fast recovery if still in recovery, for now */
1423 else if (0 && is_dack && tcp_in_recovery (tc))
1425 /* If of of the two conditions lower hold, reset dupacks because
1426 * we're probably after timeout (RFC6582 heuristics).
1427 * If Cumulative ack does not cover more than congestion threshold,
1429 * 1) The following doesn't hold: The congestion window is greater
1430 * than SMSS bytes and the difference between highest_ack
1431 * and prev_highest_ack is at most 4*SMSS bytes
1432 * 2) Echoed timestamp in the last non-dup ack does not equal the
1435 if (seq_leq (tc->snd_una, tc->snd_congestion)
1436 && ((!(tc->cwnd > tc->snd_mss
1437 && tc->bytes_acked <= 4 * tc->snd_mss))
1438 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1440 tc->rcv_dupacks = 0;
1445 if (!tc->bytes_acked)
1449 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1452 * Legitimate ACK. 1) See if we can exit recovery
1455 /* Update the pacing rate. For the first partial ack we move from
1456 * the artificially constrained rate to the one after congestion */
1457 tcp_connection_tx_pacer_update (tc);
1459 if (seq_geq (tc->snd_una, tc->snd_congestion))
1461 tcp_retransmit_timer_update (tc);
1463 /* If spurious return, we've already updated everything */
1464 if (tcp_cc_recover (tc))
1466 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1470 tc->snd_nxt = tc->snd_una_max;
1472 /* Treat as congestion avoidance ack */
1473 tcp_cc_rcv_ack (tc);
1478 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1481 /* XXX limit this only to first partial ack? */
1482 tcp_retransmit_timer_update (tc);
1484 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1485 * reset dupacks to 0. Also needed if in congestion recovery */
1486 tc->rcv_dupacks = 0;
1488 /* Post RTO timeout don't try anything fancy */
1489 if (tcp_in_recovery (tc))
1491 tcp_cc_rcv_ack (tc);
1492 transport_add_tx_event (&tc->connection);
1496 /* Remove retransmitted bytes that have been delivered */
1497 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1499 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1500 >= tc->sack_sb.last_bytes_delivered
1501 || (tc->flags & TCP_CONN_FINSNT));
1503 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1504 * remove sacked bytes delivered */
1505 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1507 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1508 - tc->sack_sb.last_bytes_delivered;
1509 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1510 tc->snd_rxt_bytes -= rxt_delivered;
1514 /* Apparently all retransmitted holes have been acked */
1515 tc->snd_rxt_bytes = 0;
1516 tc->sack_sb.high_rxt = tc->snd_una;
1521 tcp_fastrecovery_first_on (tc);
1522 /* Reuse last bytes delivered to track total bytes acked */
1523 tc->sack_sb.last_bytes_delivered += tc->bytes_acked;
1524 if (tc->snd_rxt_bytes > tc->bytes_acked)
1525 tc->snd_rxt_bytes -= tc->bytes_acked;
1527 tc->snd_rxt_bytes = 0;
1530 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1533 * Since this was a partial ack, try to retransmit some more data
1535 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1539 * Process incoming ACK
1542 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1543 tcp_header_t * th, u32 * error)
1545 u32 prev_snd_wnd, prev_snd_una;
1548 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1550 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1551 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1553 /* When we entered recovery, we reset snd_nxt to snd_una. Seems peer
1554 * still has the data so accept the ack */
1555 if (tcp_in_recovery (tc)
1556 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_congestion))
1558 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1559 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
1560 tc->snd_una_max = tc->snd_nxt;
1564 /* If we have outstanding data and this is within the window, accept it,
1565 * probably retransmit has timed out. Otherwise ACK segment and then
1567 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1569 tcp_program_ack (wrk, tc);
1570 *error = TCP_ERROR_ACK_FUTURE;
1571 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1572 vnet_buffer (b)->tcp.ack_number);
1576 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1577 vnet_buffer (b)->tcp.ack_number);
1579 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1582 /* If old ACK, probably it's an old dupack */
1583 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1585 *error = TCP_ERROR_ACK_OLD;
1586 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1587 vnet_buffer (b)->tcp.ack_number);
1588 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1589 tcp_cc_handle_event (tc, 1);
1590 /* Don't drop yet */
1595 * Looks okay, process feedback
1598 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1599 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1601 prev_snd_wnd = tc->snd_wnd;
1602 prev_snd_una = tc->snd_una;
1603 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1604 vnet_buffer (b)->tcp.ack_number,
1605 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1606 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1607 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1608 tcp_validate_txf_size (tc, tc->bytes_acked);
1610 if (tc->bytes_acked)
1612 tcp_program_dequeue (wrk, tc);
1613 tcp_update_rtt (tc, vnet_buffer (b)->tcp.ack_number);
1616 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1619 * Check if we have congestion event
1622 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1624 tcp_cc_handle_event (tc, is_dack);
1625 if (!tcp_in_cong_recovery (tc))
1627 *error = TCP_ERROR_ACK_OK;
1630 *error = TCP_ERROR_ACK_DUP;
1631 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1637 * Update congestion control (slow start/congestion avoidance)
1639 tcp_cc_update (tc, b);
1640 *error = TCP_ERROR_ACK_OK;
1645 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1647 if (!tcp_disconnect_pending (tc))
1649 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1650 tcp_disconnect_pending_on (tc);
1655 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1657 u32 thread_index, *pending_disconnects;
1658 tcp_connection_t *tc;
1661 if (!vec_len (wrk->pending_disconnects))
1664 thread_index = wrk->vm->thread_index;
1665 pending_disconnects = wrk->pending_disconnects;
1666 for (i = 0; i < vec_len (pending_disconnects); i++)
1668 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1669 tcp_disconnect_pending_off (tc);
1670 session_transport_closing_notify (&tc->connection);
1672 _vec_len (wrk->pending_disconnects) = 0;
1676 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1679 /* Account for the FIN and send ack */
1681 tcp_program_ack (wrk, tc);
1682 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1683 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1684 tcp_connection_set_state (tc, TCP_STATE_CLOSE_WAIT);
1685 tcp_program_disconnect (wrk, tc);
1686 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1687 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc);
1688 *error = TCP_ERROR_FIN_RCVD;
1692 tcp_sack_vector_is_sane (sack_block_t * sacks)
1695 for (i = 1; i < vec_len (sacks); i++)
1697 if (sacks[i - 1].end == sacks[i].start)
1704 * Build SACK list as per RFC2018.
1706 * Makes sure the first block contains the segment that generated the current
1707 * ACK and the following ones are the ones most recently reported in SACK
1710 * @param tc TCP connection for which the SACK list is updated
1711 * @param start Start sequence number of the newest SACK block
1712 * @param end End sequence of the newest SACK block
1715 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1717 sack_block_t *new_list = 0, *block = 0;
1720 /* If the first segment is ooo add it to the list. Last write might've moved
1721 * rcv_nxt over the first segment. */
1722 if (seq_lt (tc->rcv_nxt, start))
1724 vec_add2 (new_list, block, 1);
1725 block->start = start;
1729 /* Find the blocks still worth keeping. */
1730 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1732 /* Discard if rcv_nxt advanced beyond current block */
1733 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1736 /* Merge or drop if segment overlapped by the new segment */
1737 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1738 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1740 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1741 new_list[0].start = tc->snd_sacks[i].start;
1742 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1743 new_list[0].end = tc->snd_sacks[i].end;
1747 /* Save to new SACK list if we have space. */
1748 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1750 vec_add1 (new_list, tc->snd_sacks[i]);
1754 clib_warning ("sack discarded");
1758 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1760 /* Replace old vector with new one */
1761 vec_free (tc->snd_sacks);
1762 tc->snd_sacks = new_list;
1764 /* Segments should not 'touch' */
1765 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1769 tcp_sack_list_bytes (tcp_connection_t * tc)
1772 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1773 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1777 /** Enqueue data for delivery to application */
1779 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1782 int written, error = TCP_ERROR_ENQUEUED;
1784 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1786 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1787 1 /* queue event */ , 1);
1789 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1791 /* Update rcv_nxt */
1792 if (PREDICT_TRUE (written == data_len))
1794 tc->rcv_nxt += written;
1796 /* If more data written than expected, account for out-of-order bytes. */
1797 else if (written > data_len)
1799 tc->rcv_nxt += written;
1800 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1802 else if (written > 0)
1804 /* We've written something but FIFO is probably full now */
1805 tc->rcv_nxt += written;
1806 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1810 return TCP_ERROR_FIFO_FULL;
1813 /* Update SACK list if need be */
1814 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1816 /* Remove SACK blocks that have been delivered */
1817 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1823 /** Enqueue out-of-order data */
1825 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1831 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1834 /* Enqueue out-of-order data with relative offset */
1835 rv = session_enqueue_stream_connection (&tc->connection, b,
1836 vnet_buffer (b)->tcp.seq_number -
1837 tc->rcv_nxt, 0 /* queue event */ ,
1840 /* Nothing written */
1843 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1844 return TCP_ERROR_FIFO_FULL;
1847 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1849 /* Update SACK list if in use */
1850 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1852 ooo_segment_t *newest;
1855 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1857 /* Get the newest segment from the fifo */
1858 newest = svm_fifo_newest_ooo_segment (s0->rx_fifo);
1861 offset = ooo_segment_offset (s0->rx_fifo, newest);
1862 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1863 start = tc->rcv_nxt + offset;
1864 end = start + ooo_segment_length (s0->rx_fifo, newest);
1865 tcp_update_sack_list (tc, start, end);
1866 svm_fifo_newest_ooo_segment_reset (s0->rx_fifo);
1867 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1871 return TCP_ERROR_ENQUEUED_OOO;
1875 * Check if ACK could be delayed. If ack can be delayed, it should return
1876 * true for a full frame. If we're always acking return 0.
1879 tcp_can_delack (tcp_connection_t * tc)
1881 /* Send ack if ... */
1883 /* just sent a rcv wnd 0 */
1884 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1885 /* constrained to send ack */
1886 || (tc->flags & TCP_CONN_SNDACK) != 0
1887 /* we're almost out of tx wnd */
1888 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1895 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1897 u32 discard, first = b->current_length;
1898 vlib_main_t *vm = vlib_get_main ();
1900 /* Handle multi-buffer segments */
1901 if (n_bytes_to_drop > b->current_length)
1903 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1907 discard = clib_min (n_bytes_to_drop, b->current_length);
1908 vlib_buffer_advance (b, discard);
1909 b = vlib_get_buffer (vm, b->next_buffer);
1910 n_bytes_to_drop -= discard;
1912 while (n_bytes_to_drop);
1913 if (n_bytes_to_drop > first)
1914 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1917 vlib_buffer_advance (b, n_bytes_to_drop);
1918 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1923 * Receive buffer for connection and handle acks
1925 * It handles both in order or out-of-order data.
1928 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1931 u32 error, n_bytes_to_drop, n_data_bytes;
1933 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1934 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1935 ASSERT (n_data_bytes);
1937 /* Handle out-of-order data */
1938 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1940 /* Old sequence numbers allowed through because they overlapped
1942 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1944 /* Completely in the past (possible retransmit). Ack
1945 * retransmissions since we may not have any data to send */
1946 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1948 tcp_program_ack (wrk, tc);
1949 error = TCP_ERROR_SEGMENT_OLD;
1953 /* Chop off the bytes in the past and see if what is left
1954 * can be enqueued in order */
1955 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1956 n_data_bytes -= n_bytes_to_drop;
1957 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1958 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1960 error = TCP_ERROR_SEGMENT_OLD;
1966 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1967 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1968 tcp_program_dupack (wrk, tc);
1969 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1975 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1976 * segments can be enqueued after fifo tail offset changes. */
1977 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1978 if (tcp_can_delack (tc))
1980 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1981 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1985 tcp_program_ack (wrk, tc);
1993 tcp_header_t tcp_header;
1994 tcp_connection_t tcp_connection;
1998 format_tcp_rx_trace (u8 * s, va_list * args)
2000 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2001 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2002 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2003 u32 indent = format_get_indent (s);
2005 s = format (s, "%U\n%U%U",
2006 format_tcp_header, &t->tcp_header, 128,
2007 format_white_space, indent,
2008 format_tcp_connection, &t->tcp_connection, 1);
2014 format_tcp_rx_trace_short (u8 * s, va_list * args)
2016 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2017 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2018 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2020 s = format (s, "%d -> %d (%U)",
2021 clib_net_to_host_u16 (t->tcp_header.dst_port),
2022 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
2023 t->tcp_connection.state);
2029 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
2030 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
2034 clib_memcpy_fast (&t0->tcp_connection, tc0,
2035 sizeof (t0->tcp_connection));
2039 th0 = tcp_buffer_hdr (b0);
2041 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2045 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2046 vlib_frame_t * frame, u8 is_ip4)
2050 n_left = frame->n_vectors;
2051 from = vlib_frame_vector_args (frame);
2055 tcp_connection_t *tc0;
2062 b0 = vlib_get_buffer (vm, bi0);
2064 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2066 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2067 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2069 th0 = tcp_buffer_hdr (b0);
2070 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2079 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2080 u8 is_ip4, u32 evt, u32 val)
2083 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2085 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2088 #define tcp_maybe_inc_counter(node_id, err, count) \
2090 if (next0 != tcp_next_drop (is_ip4)) \
2091 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2092 tcp6_##node_id##_node.index, is_ip4, err, \
2095 #define tcp_inc_counter(node_id, err, count) \
2096 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2097 tcp6_##node_id##_node.index, is_ip4, \
2099 #define tcp_maybe_inc_err_counter(cnts, err) \
2101 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2103 #define tcp_inc_err_counter(cnts, err, val) \
2107 #define tcp_store_err_counters(node_id, cnts) \
2110 for (i = 0; i < TCP_N_ERROR; i++) \
2112 tcp_inc_counter(node_id, i, cnts[i]); \
2117 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2118 vlib_frame_t * frame, int is_ip4)
2120 u32 thread_index = vm->thread_index, errors = 0;
2121 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2122 u32 n_left_from, *from, *first_buffer;
2123 u16 err_counters[TCP_N_ERROR] = { 0 };
2125 if (node->flags & VLIB_NODE_FLAG_TRACE)
2126 tcp_established_trace_frame (vm, node, frame, is_ip4);
2128 first_buffer = from = vlib_frame_vector_args (frame);
2129 n_left_from = frame->n_vectors;
2131 while (n_left_from > 0)
2133 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2136 tcp_connection_t *tc0;
2138 if (n_left_from > 1)
2141 pb = vlib_get_buffer (vm, from[1]);
2142 vlib_prefetch_buffer_header (pb, LOAD);
2143 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2150 b0 = vlib_get_buffer (vm, bi0);
2151 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2154 if (PREDICT_FALSE (tc0 == 0))
2156 error0 = TCP_ERROR_INVALID_CONNECTION;
2160 th0 = tcp_buffer_hdr (b0);
2162 /* TODO header prediction fast path */
2164 /* 1-4: check SEQ, RST, SYN */
2165 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2167 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2171 /* 5: check the ACK field */
2172 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2175 /* 6: check the URG bit TODO */
2177 /* 7: process the segment text */
2178 if (vnet_buffer (b0)->tcp.data_len)
2179 error0 = tcp_segment_rcv (wrk, tc0, b0);
2181 /* 8: check the FIN bit */
2182 if (PREDICT_FALSE (tcp_is_fin (th0)))
2183 tcp_rcv_fin (wrk, tc0, b0, &error0);
2186 tcp_inc_err_counter (err_counters, error0, 1);
2189 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2191 err_counters[TCP_ERROR_MSG_QUEUE_FULL] = errors;
2192 tcp_store_err_counters (established, err_counters);
2193 tcp_handle_postponed_dequeues (wrk);
2194 tcp_handle_disconnects (wrk);
2195 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2197 return frame->n_vectors;
2201 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2202 vlib_frame_t * from_frame)
2204 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2208 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2209 vlib_frame_t * from_frame)
2211 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2215 VLIB_REGISTER_NODE (tcp4_established_node) =
2217 .function = tcp4_established,
2218 .name = "tcp4-established",
2219 /* Takes a vector of packets. */
2220 .vector_size = sizeof (u32),
2221 .n_errors = TCP_N_ERROR,
2222 .error_strings = tcp_error_strings,
2223 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2226 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2227 foreach_tcp_state_next
2230 .format_trace = format_tcp_rx_trace_short,
2234 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
2237 VLIB_REGISTER_NODE (tcp6_established_node) =
2239 .function = tcp6_established,
2240 .name = "tcp6-established",
2241 /* Takes a vector of packets. */
2242 .vector_size = sizeof (u32),
2243 .n_errors = TCP_N_ERROR,
2244 .error_strings = tcp_error_strings,
2245 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2248 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2249 foreach_tcp_state_next
2252 .format_trace = format_tcp_rx_trace_short,
2257 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
2259 vlib_node_registration_t tcp4_syn_sent_node;
2260 vlib_node_registration_t tcp6_syn_sent_node;
2263 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2265 transport_connection_t *tmp = 0;
2272 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2275 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2276 && (tc->state == TCP_STATE_LISTEN
2277 || tc->c_rmt_port == hdr->src_port));
2281 handle = session_lookup_half_open_handle (&tc->connection);
2282 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2283 tc->c_proto, tc->c_is_ip4);
2287 if (tmp->lcl_port == hdr->dst_port
2288 && tmp->rmt_port == hdr->src_port)
2290 TCP_DBG ("half-open is valid!");
2298 * Lookup transport connection
2300 static tcp_connection_t *
2301 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2305 transport_connection_t *tconn;
2306 tcp_connection_t *tc;
2311 ip4 = vlib_buffer_get_current (b);
2312 tcp = ip4_next_header (ip4);
2313 tconn = session_lookup_connection_wt4 (fib_index,
2318 TRANSPORT_PROTO_TCP,
2319 thread_index, &is_filtered);
2320 tc = tcp_get_connection_from_transport (tconn);
2321 ASSERT (tcp_lookup_is_valid (tc, tcp));
2326 ip6 = vlib_buffer_get_current (b);
2327 tcp = ip6_next_header (ip6);
2328 tconn = session_lookup_connection_wt6 (fib_index,
2333 TRANSPORT_PROTO_TCP,
2334 thread_index, &is_filtered);
2335 tc = tcp_get_connection_from_transport (tconn);
2336 ASSERT (tcp_lookup_is_valid (tc, tcp));
2342 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2343 vlib_frame_t * from_frame, int is_ip4)
2345 tcp_main_t *tm = vnet_get_tcp_main ();
2346 u32 n_left_from, *from, *first_buffer, errors = 0;
2347 u32 my_thread_index = vm->thread_index;
2348 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2350 from = first_buffer = vlib_frame_vector_args (from_frame);
2351 n_left_from = from_frame->n_vectors;
2353 while (n_left_from > 0)
2355 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2356 tcp_connection_t *tc0, *new_tc0;
2357 tcp_header_t *tcp0 = 0;
2365 b0 = vlib_get_buffer (vm, bi0);
2367 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2368 if (PREDICT_FALSE (tc0 == 0))
2370 error0 = TCP_ERROR_INVALID_CONNECTION;
2374 /* Half-open completed recently but the connection was't removed
2375 * yet by the owning thread */
2376 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2378 /* Make sure the connection actually exists */
2379 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2380 my_thread_index, is_ip4));
2381 error0 = TCP_ERROR_SPURIOUS_SYN_ACK;
2385 ack0 = vnet_buffer (b0)->tcp.ack_number;
2386 seq0 = vnet_buffer (b0)->tcp.seq_number;
2387 tcp0 = tcp_buffer_hdr (b0);
2389 /* Crude check to see if the connection handle does not match
2390 * the packet. Probably connection just switched to established */
2391 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2392 || tcp0->src_port != tc0->c_rmt_port))
2394 error0 = TCP_ERROR_INVALID_CONNECTION;
2398 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2399 && !tcp_syn (tcp0)))
2401 error0 = TCP_ERROR_SEGMENT_INVALID;
2405 /* SYNs consume sequence numbers */
2406 vnet_buffer (b0)->tcp.seq_end += tcp_is_syn (tcp0);
2409 * 1. check the ACK bit
2413 * If the ACK bit is set
2414 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2415 * the RST bit is set, if so drop the segment and return)
2416 * <SEQ=SEG.ACK><CTL=RST>
2417 * and discard the segment. Return.
2418 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2422 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2424 if (!tcp_rst (tcp0))
2425 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2426 error0 = TCP_ERROR_RCV_WND;
2430 /* Make sure ACK is valid */
2431 if (seq_gt (tc0->snd_una, ack0))
2433 error0 = TCP_ERROR_ACK_INVALID;
2439 * 2. check the RST bit
2444 /* If ACK is acceptable, signal client that peer is not
2445 * willing to accept connection and drop connection*/
2447 tcp_connection_reset (tc0);
2448 error0 = TCP_ERROR_RST_RCVD;
2453 * 3. check the security and precedence (skipped)
2457 * 4. check the SYN bit
2460 /* No SYN flag. Drop. */
2461 if (!tcp_syn (tcp0))
2463 error0 = TCP_ERROR_SEGMENT_INVALID;
2468 if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1))
2470 error0 = TCP_ERROR_OPTIONS;
2474 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2475 * current thread pool. */
2476 pool_get (tm->connections[my_thread_index], new_tc0);
2477 clib_memcpy_fast (new_tc0, tc0, sizeof (*new_tc0));
2478 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2479 new_tc0->c_thread_index = my_thread_index;
2480 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2481 new_tc0->irs = seq0;
2482 new_tc0->timers[TCP_TIMER_ESTABLISH_AO] = TCP_TIMER_HANDLE_INVALID;
2483 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2484 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2486 /* If this is not the owning thread, wait for syn retransmit to
2487 * expire and cleanup then */
2488 if (tcp_half_open_connection_cleanup (tc0))
2489 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2491 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2493 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2494 new_tc0->tsval_recent_age = tcp_time_now ();
2497 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2498 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2500 new_tc0->rcv_wscale = 0;
2502 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2503 << new_tc0->snd_wscale;
2504 new_tc0->snd_wl1 = seq0;
2505 new_tc0->snd_wl2 = ack0;
2507 tcp_connection_init_vars (new_tc0);
2509 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2510 if (PREDICT_TRUE (tcp_ack (tcp0)))
2512 /* Our SYN is ACKed: we have iss < ack = snd_una */
2514 /* TODO Dequeue acknowledged segments if we support Fast Open */
2515 new_tc0->snd_una = ack0;
2516 new_tc0->state = TCP_STATE_ESTABLISHED;
2518 /* Make sure las is initialized for the wnd computation */
2519 new_tc0->rcv_las = new_tc0->rcv_nxt;
2521 /* Notify app that we have connection. If session layer can't
2522 * allocate session send reset */
2523 if (session_stream_connect_notify (&new_tc0->connection, 0))
2525 clib_warning ("connect notify fail");
2526 tcp_send_reset_w_pkt (new_tc0, b0, my_thread_index, is_ip4);
2527 tcp_connection_cleanup (new_tc0);
2531 new_tc0->tx_fifo_size =
2532 transport_tx_fifo_size (&new_tc0->connection);
2533 /* Update rtt with the syn-ack sample */
2534 tcp_estimate_initial_rtt (new_tc0);
2535 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2536 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2538 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2541 new_tc0->state = TCP_STATE_SYN_RCVD;
2543 /* Notify app that we have connection */
2544 if (session_stream_connect_notify (&new_tc0->connection, 0))
2546 tcp_connection_cleanup (new_tc0);
2547 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2548 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2552 new_tc0->tx_fifo_size =
2553 transport_tx_fifo_size (&new_tc0->connection);
2554 new_tc0->rtt_ts = 0;
2555 tcp_init_snd_vars (new_tc0);
2556 tcp_send_synack (new_tc0);
2557 error0 = TCP_ERROR_SYNS_RCVD;
2561 /* Read data, if any */
2562 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2564 clib_warning ("rcvd data in syn-sent");
2565 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2566 if (error0 == TCP_ERROR_ACK_OK)
2567 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2571 tcp_program_ack (wrk, new_tc0);
2576 tcp_inc_counter (syn_sent, error0, 1);
2577 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2579 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2580 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2581 clib_memcpy_fast (&t0->tcp_connection, tc0,
2582 sizeof (t0->tcp_connection));
2586 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2588 tcp_inc_counter (syn_sent, TCP_ERROR_MSG_QUEUE_FULL, errors);
2589 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2591 return from_frame->n_vectors;
2595 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2596 vlib_frame_t * from_frame)
2598 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2602 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2603 vlib_frame_t * from_frame)
2605 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2609 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2611 .function = tcp4_syn_sent,
2612 .name = "tcp4-syn-sent",
2613 /* Takes a vector of packets. */
2614 .vector_size = sizeof (u32),
2615 .n_errors = TCP_N_ERROR,
2616 .error_strings = tcp_error_strings,
2617 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2620 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2621 foreach_tcp_state_next
2624 .format_trace = format_tcp_rx_trace_short,
2628 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2631 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2633 .function = tcp6_syn_sent_rcv,
2634 .name = "tcp6-syn-sent",
2635 /* Takes a vector of packets. */
2636 .vector_size = sizeof (u32),
2637 .n_errors = TCP_N_ERROR,
2638 .error_strings = tcp_error_strings,
2639 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2642 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2643 foreach_tcp_state_next
2646 .format_trace = format_tcp_rx_trace_short,
2650 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2652 vlib_node_registration_t tcp4_rcv_process_node;
2653 vlib_node_registration_t tcp6_rcv_process_node;
2656 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2657 * as per RFC793 p. 64
2660 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2661 vlib_frame_t * from_frame, int is_ip4)
2663 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2664 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2665 u32 n_left_from, *from, max_dequeue;
2667 from = first_buffer = vlib_frame_vector_args (from_frame);
2668 n_left_from = from_frame->n_vectors;
2670 while (n_left_from > 0)
2672 u32 bi0, error0 = TCP_ERROR_NONE;
2673 tcp_header_t *tcp0 = 0;
2674 tcp_connection_t *tc0;
2682 b0 = vlib_get_buffer (vm, bi0);
2683 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2685 if (PREDICT_FALSE (tc0 == 0))
2687 error0 = TCP_ERROR_INVALID_CONNECTION;
2691 tcp0 = tcp_buffer_hdr (b0);
2692 is_fin0 = tcp_is_fin (tcp0);
2696 tcp_connection_t *tmp;
2697 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2699 if (tmp->state != tc0->state)
2701 if (tc0->state != TCP_STATE_CLOSED)
2702 clib_warning ("state changed");
2708 * Special treatment for CLOSED
2710 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2712 error0 = TCP_ERROR_CONNECTION_CLOSED;
2717 * For all other states (except LISTEN)
2720 /* 1-4: check SEQ, RST, SYN */
2721 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2724 /* 5: check the ACK field */
2727 case TCP_STATE_SYN_RCVD:
2729 * If the segment acknowledgment is not acceptable, form a
2731 * <SEQ=SEG.ACK><CTL=RST>
2734 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2736 tcp_connection_reset (tc0);
2737 error0 = TCP_ERROR_ACK_INVALID;
2741 /* Make sure the ack is exactly right */
2742 if (tc0->rcv_nxt != vnet_buffer (b0)->tcp.seq_number || is_fin0)
2744 tcp_connection_reset (tc0);
2745 error0 = TCP_ERROR_SEGMENT_INVALID;
2749 /* Update rtt and rto */
2750 tcp_estimate_initial_rtt (tc0);
2752 /* Switch state to ESTABLISHED */
2753 tc0->state = TCP_STATE_ESTABLISHED;
2754 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2756 /* Initialize session variables */
2757 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2758 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2759 << tc0->rcv_opts.wscale;
2760 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2761 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2763 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2764 tcp_retransmit_timer_reset (tc0);
2765 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2766 if (session_stream_accept_notify (&tc0->connection))
2768 error0 = TCP_ERROR_MSG_QUEUE_FULL;
2769 tcp_connection_reset (tc0);
2772 error0 = TCP_ERROR_ACK_OK;
2774 case TCP_STATE_ESTABLISHED:
2775 /* We can get packets in established state here because they
2776 * were enqueued before state change */
2777 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2781 case TCP_STATE_FIN_WAIT_1:
2782 /* In addition to the processing for the ESTABLISHED state, if
2783 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2784 * continue processing in that state. */
2785 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2788 /* Still have to send the FIN */
2789 if (tc0->flags & TCP_CONN_FINPNDG)
2791 /* TX fifo finally drained */
2792 max_dequeue = session_tx_fifo_max_dequeue (&tc0->connection);
2793 if (max_dequeue <= tc0->burst_acked)
2796 /* If FIN is ACKed */
2797 else if (tc0->snd_una == tc0->snd_una_max)
2799 tcp_connection_set_state (tc0, TCP_STATE_FIN_WAIT_2);
2801 /* Stop all retransmit timers because we have nothing more
2802 * to send. Enable waitclose though because we're willing to
2803 * wait for peer's FIN but not indefinitely. */
2804 tcp_connection_timers_reset (tc0);
2805 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2807 /* Don't try to deq the FIN acked */
2808 if (tc0->burst_acked > 1)
2809 stream_session_dequeue_drop (&tc0->connection,
2810 tc0->burst_acked - 1);
2811 tc0->burst_acked = 0;
2814 case TCP_STATE_FIN_WAIT_2:
2815 /* In addition to the processing for the ESTABLISHED state, if
2816 * the retransmission queue is empty, the user's CLOSE can be
2817 * acknowledged ("ok") but do not delete the TCB. */
2818 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2820 tc0->burst_acked = 0;
2822 case TCP_STATE_CLOSE_WAIT:
2823 /* Do the same processing as for the ESTABLISHED state. */
2824 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2827 if (tc0->flags & TCP_CONN_FINPNDG)
2829 /* TX fifo finally drained */
2830 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2833 tcp_connection_timers_reset (tc0);
2834 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2835 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2839 case TCP_STATE_CLOSING:
2840 /* In addition to the processing for the ESTABLISHED state, if
2841 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2842 * otherwise ignore the segment. */
2843 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2846 tcp_connection_timers_reset (tc0);
2847 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2848 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2852 case TCP_STATE_LAST_ACK:
2853 /* The only thing that [should] arrive in this state is an
2854 * acknowledgment of our FIN. If our FIN is now acknowledged,
2855 * delete the TCB, enter the CLOSED state, and return. */
2857 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2859 error0 = TCP_ERROR_ACK_INVALID;
2862 error0 = TCP_ERROR_ACK_OK;
2863 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2864 /* Apparently our ACK for the peer's FIN was lost */
2865 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2871 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2873 /* Don't free the connection from the data path since
2874 * we can't ensure that we have no packets already enqueued
2875 * to output. Rely instead on the waitclose timer */
2876 tcp_connection_timers_reset (tc0);
2877 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2882 case TCP_STATE_TIME_WAIT:
2883 /* The only thing that can arrive in this state is a
2884 * retransmission of the remote FIN. Acknowledge it, and restart
2885 * the 2 MSL timeout. */
2887 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2890 tcp_program_ack (wrk, tc0);
2891 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2899 /* 6: check the URG bit TODO */
2901 /* 7: process the segment text */
2904 case TCP_STATE_ESTABLISHED:
2905 case TCP_STATE_FIN_WAIT_1:
2906 case TCP_STATE_FIN_WAIT_2:
2907 if (vnet_buffer (b0)->tcp.data_len)
2908 error0 = tcp_segment_rcv (wrk, tc0, b0);
2910 case TCP_STATE_CLOSE_WAIT:
2911 case TCP_STATE_CLOSING:
2912 case TCP_STATE_LAST_ACK:
2913 case TCP_STATE_TIME_WAIT:
2914 /* This should not occur, since a FIN has been received from the
2915 * remote side. Ignore the segment text. */
2919 /* 8: check the FIN bit */
2923 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2927 case TCP_STATE_ESTABLISHED:
2928 /* Account for the FIN and send ack */
2930 tcp_program_ack (wrk, tc0);
2931 tcp_connection_set_state (tc0, TCP_STATE_CLOSE_WAIT);
2932 tcp_program_disconnect (wrk, tc0);
2933 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
2935 case TCP_STATE_SYN_RCVD:
2936 /* Send FIN-ACK, enter LAST-ACK and because the app was not
2937 * notified yet, set a cleanup timer instead of relying on
2938 * disconnect notify and the implicit close call. */
2939 tcp_connection_timers_reset (tc0);
2942 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2943 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2945 case TCP_STATE_CLOSE_WAIT:
2946 case TCP_STATE_CLOSING:
2947 case TCP_STATE_LAST_ACK:
2950 case TCP_STATE_FIN_WAIT_1:
2952 tcp_connection_set_state (tc0, TCP_STATE_CLOSING);
2953 tcp_program_ack (wrk, tc0);
2954 /* Wait for ACK but not forever */
2955 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2957 case TCP_STATE_FIN_WAIT_2:
2958 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2960 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2961 tcp_connection_timers_reset (tc0);
2962 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2963 tcp_program_ack (wrk, tc0);
2965 case TCP_STATE_TIME_WAIT:
2966 /* Remain in the TIME-WAIT state. Restart the time-wait
2969 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2972 error0 = TCP_ERROR_FIN_RCVD;
2976 tcp_inc_counter (rcv_process, error0, 1);
2977 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2979 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2980 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2984 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2986 tcp_inc_counter (rcv_process, TCP_ERROR_MSG_QUEUE_FULL, errors);
2987 tcp_handle_postponed_dequeues (wrk);
2988 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2990 return from_frame->n_vectors;
2994 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2995 vlib_frame_t * from_frame)
2997 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3001 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
3002 vlib_frame_t * from_frame)
3004 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3008 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
3010 .function = tcp4_rcv_process,
3011 .name = "tcp4-rcv-process",
3012 /* Takes a vector of packets. */
3013 .vector_size = sizeof (u32),
3014 .n_errors = TCP_N_ERROR,
3015 .error_strings = tcp_error_strings,
3016 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3019 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3020 foreach_tcp_state_next
3023 .format_trace = format_tcp_rx_trace_short,
3027 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
3030 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
3032 .function = tcp6_rcv_process,
3033 .name = "tcp6-rcv-process",
3034 /* Takes a vector of packets. */
3035 .vector_size = sizeof (u32),
3036 .n_errors = TCP_N_ERROR,
3037 .error_strings = tcp_error_strings,
3038 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3041 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3042 foreach_tcp_state_next
3045 .format_trace = format_tcp_rx_trace_short,
3049 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
3051 vlib_node_registration_t tcp4_listen_node;
3052 vlib_node_registration_t tcp6_listen_node;
3055 * LISTEN state processing as per RFC 793 p. 65
3058 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3059 vlib_frame_t * from_frame, int is_ip4)
3061 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3062 u32 my_thread_index = vm->thread_index;
3064 from = first_buffer = vlib_frame_vector_args (from_frame);
3065 n_left_from = from_frame->n_vectors;
3067 while (n_left_from > 0)
3072 tcp_header_t *th0 = 0;
3073 tcp_connection_t *lc0;
3076 tcp_connection_t *child0;
3077 u32 error0 = TCP_ERROR_NONE;
3083 b0 = vlib_get_buffer (vm, bi0);
3084 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3088 ip40 = vlib_buffer_get_current (b0);
3089 th0 = ip4_next_header (ip40);
3093 ip60 = vlib_buffer_get_current (b0);
3094 th0 = ip6_next_header (ip60);
3097 /* Create child session. For syn-flood protection use filter */
3099 /* 1. first check for an RST: handled in dispatch */
3100 /* if (tcp_rst (th0))
3104 /* 2. second check for an ACK: handled in dispatch */
3105 /* if (tcp_ack (th0))
3107 tcp_send_reset (b0, is_ip4);
3112 /* 3. check for a SYN (did that already) */
3114 /* Make sure connection wasn't just created */
3115 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3117 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3119 error0 = TCP_ERROR_CREATE_EXISTS;
3123 /* Create child session and send SYN-ACK */
3124 child0 = tcp_connection_alloc (my_thread_index);
3125 child0->c_lcl_port = th0->dst_port;
3126 child0->c_rmt_port = th0->src_port;
3127 child0->c_is_ip4 = is_ip4;
3128 child0->state = TCP_STATE_SYN_RCVD;
3129 child0->c_fib_index = lc0->c_fib_index;
3133 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3134 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3138 clib_memcpy_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3139 sizeof (ip6_address_t));
3140 clib_memcpy_fast (&child0->c_rmt_ip6, &ip60->src_address,
3141 sizeof (ip6_address_t));
3144 if (tcp_options_parse (th0, &child0->rcv_opts, 1))
3146 error0 = TCP_ERROR_OPTIONS;
3147 tcp_connection_free (child0);
3151 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3152 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3153 child0->rcv_las = child0->rcv_nxt;
3154 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3156 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3157 * segments are used to initialize PAWS. */
3158 if (tcp_opts_tstamp (&child0->rcv_opts))
3160 child0->tsval_recent = child0->rcv_opts.tsval;
3161 child0->tsval_recent_age = tcp_time_now ();
3164 if (tcp_opts_wscale (&child0->rcv_opts))
3165 child0->snd_wscale = child0->rcv_opts.wscale;
3167 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3168 << child0->snd_wscale;
3169 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3170 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3172 tcp_connection_init_vars (child0);
3173 child0->rto = TCP_RTO_MIN;
3174 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
3176 if (session_stream_accept (&child0->connection, lc0->c_s_index,
3179 tcp_connection_cleanup (child0);
3180 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3184 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3185 tcp_send_synack (child0);
3186 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
3190 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3192 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3193 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3194 clib_memcpy_fast (&t0->tcp_connection, lc0,
3195 sizeof (t0->tcp_connection));
3198 n_syns += (error0 == TCP_ERROR_NONE);
3201 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3202 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3204 return from_frame->n_vectors;
3208 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3209 vlib_frame_t * from_frame)
3211 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3215 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3216 vlib_frame_t * from_frame)
3218 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3222 VLIB_REGISTER_NODE (tcp4_listen_node) =
3224 .function = tcp4_listen,
3225 .name = "tcp4-listen",
3226 /* Takes a vector of packets. */
3227 .vector_size = sizeof (u32),
3228 .n_errors = TCP_N_ERROR,
3229 .error_strings = tcp_error_strings,
3230 .n_next_nodes = TCP_LISTEN_N_NEXT,
3233 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3234 foreach_tcp_state_next
3237 .format_trace = format_tcp_rx_trace_short,
3241 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
3244 VLIB_REGISTER_NODE (tcp6_listen_node) =
3246 .function = tcp6_listen,
3247 .name = "tcp6-listen",
3248 /* Takes a vector of packets. */
3249 .vector_size = sizeof (u32),
3250 .n_errors = TCP_N_ERROR,
3251 .error_strings = tcp_error_strings,
3252 .n_next_nodes = TCP_LISTEN_N_NEXT,
3255 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3256 foreach_tcp_state_next
3259 .format_trace = format_tcp_rx_trace_short,
3263 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
3265 vlib_node_registration_t tcp4_input_node;
3266 vlib_node_registration_t tcp6_input_node;
3268 typedef enum _tcp_input_next
3270 TCP_INPUT_NEXT_DROP,
3271 TCP_INPUT_NEXT_LISTEN,
3272 TCP_INPUT_NEXT_RCV_PROCESS,
3273 TCP_INPUT_NEXT_SYN_SENT,
3274 TCP_INPUT_NEXT_ESTABLISHED,
3275 TCP_INPUT_NEXT_RESET,
3276 TCP_INPUT_NEXT_PUNT,
3280 #define foreach_tcp4_input_next \
3281 _ (DROP, "ip4-drop") \
3282 _ (LISTEN, "tcp4-listen") \
3283 _ (RCV_PROCESS, "tcp4-rcv-process") \
3284 _ (SYN_SENT, "tcp4-syn-sent") \
3285 _ (ESTABLISHED, "tcp4-established") \
3286 _ (RESET, "tcp4-reset") \
3287 _ (PUNT, "ip4-punt")
3289 #define foreach_tcp6_input_next \
3290 _ (DROP, "ip6-drop") \
3291 _ (LISTEN, "tcp6-listen") \
3292 _ (RCV_PROCESS, "tcp6-rcv-process") \
3293 _ (SYN_SENT, "tcp6-syn-sent") \
3294 _ (ESTABLISHED, "tcp6-established") \
3295 _ (RESET, "tcp6-reset") \
3296 _ (PUNT, "ip6-punt")
3298 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3301 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3302 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3304 tcp_connection_t *tc;
3309 for (i = 0; i < n_bufs; i++)
3311 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3313 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3314 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3316 tcp = vlib_buffer_get_current (bs[i]);
3317 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3323 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3325 if (*error == TCP_ERROR_FILTERED || *error == TCP_ERROR_WRONG_THREAD)
3327 *next = TCP_INPUT_NEXT_DROP;
3329 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3331 *next = TCP_INPUT_NEXT_PUNT;
3332 *error = TCP_ERROR_PUNT;
3336 *next = TCP_INPUT_NEXT_RESET;
3337 *error = TCP_ERROR_NO_LISTENER;
3341 static inline tcp_connection_t *
3342 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3345 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3346 int n_advance_bytes, n_data_bytes;
3347 transport_connection_t *tc;
3353 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3354 int ip_hdr_bytes = ip4_header_bytes (ip4);
3355 if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
3357 *error = TCP_ERROR_LENGTH;
3360 tcp = ip4_next_header (ip4);
3361 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3362 n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
3363 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3365 /* Length check. Checksum computed by ipx_local no need to compute again */
3366 if (PREDICT_FALSE (n_data_bytes < 0))
3368 *error = TCP_ERROR_LENGTH;
3372 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3373 &ip4->src_address, tcp->dst_port,
3374 tcp->src_port, TRANSPORT_PROTO_TCP,
3375 thread_index, &result);
3379 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3380 if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
3382 *error = TCP_ERROR_LENGTH;
3385 tcp = ip6_next_header (ip6);
3386 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3387 n_advance_bytes = tcp_header_bytes (tcp);
3388 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3390 n_advance_bytes += sizeof (ip6[0]);
3392 if (PREDICT_FALSE (n_data_bytes < 0))
3394 *error = TCP_ERROR_LENGTH;
3398 (ip6_address_is_link_local_unicast (&ip6->dst_address)))
3400 ip4_main_t *im = &ip4_main;
3401 fib_index = vec_elt (im->fib_index_by_sw_if_index,
3402 vnet_buffer (b)->sw_if_index[VLIB_RX]);
3405 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3406 &ip6->src_address, tcp->dst_port,
3407 tcp->src_port, TRANSPORT_PROTO_TCP,
3408 thread_index, &result);
3411 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3412 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3413 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3414 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3415 vnet_buffer (b)->tcp.seq_end = vnet_buffer (b)->tcp.seq_number
3417 vnet_buffer (b)->tcp.flags = 0;
3419 *error = result ? TCP_ERROR_NONE + result : *error;
3421 return tcp_get_connection_from_transport (tc);
3425 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3426 vlib_buffer_t * b, u16 * next, u32 * error)
3431 tcp = tcp_buffer_hdr (b);
3432 flags = tcp->flags & filter_flags;
3433 *next = tm->dispatch_table[tc->state][flags].next;
3434 *error = tm->dispatch_table[tc->state][flags].error;
3436 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3437 || *next == TCP_INPUT_NEXT_RESET))
3439 /* Overload tcp flags to store state */
3440 tcp_state_t state = tc->state;
3441 vnet_buffer (b)->tcp.flags = tc->state;
3443 if (*error == TCP_ERROR_DISPATCH)
3444 clib_warning ("tcp conn %u disp error state %U flags %U",
3445 tc->c_c_index, format_tcp_state, state,
3446 format_tcp_flags, (int) flags);
3451 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3452 vlib_frame_t * frame, int is_ip4)
3454 u32 n_left_from, *from, thread_index = vm->thread_index;
3455 tcp_main_t *tm = vnet_get_tcp_main ();
3456 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3457 u16 nexts[VLIB_FRAME_SIZE], *next;
3459 tcp_set_time_now (tcp_get_worker (thread_index));
3461 from = vlib_frame_vector_args (frame);
3462 n_left_from = frame->n_vectors;
3463 vlib_get_buffers (vm, from, bufs, n_left_from);
3468 while (n_left_from >= 4)
3470 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3471 tcp_connection_t *tc0, *tc1;
3474 vlib_prefetch_buffer_header (b[2], STORE);
3475 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3477 vlib_prefetch_buffer_header (b[3], STORE);
3478 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3481 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3483 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3484 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4);
3486 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3488 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3489 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3491 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3492 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3494 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3495 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3499 if (PREDICT_TRUE (tc0 != 0))
3501 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3502 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3503 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3506 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3508 if (PREDICT_TRUE (tc1 != 0))
3510 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3511 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3512 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3515 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3522 while (n_left_from > 0)
3524 tcp_connection_t *tc0;
3525 u32 error0 = TCP_ERROR_NO_LISTENER;
3527 if (n_left_from > 1)
3529 vlib_prefetch_buffer_header (b[1], STORE);
3530 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3533 next[0] = TCP_INPUT_NEXT_DROP;
3534 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3535 if (PREDICT_TRUE (tc0 != 0))
3537 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3538 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3539 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3542 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3549 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3550 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3552 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3553 return frame->n_vectors;
3557 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3558 vlib_frame_t * from_frame)
3560 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3564 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3565 vlib_frame_t * from_frame)
3567 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3571 VLIB_REGISTER_NODE (tcp4_input_node) =
3573 .function = tcp4_input,
3574 .name = "tcp4-input",
3575 /* Takes a vector of packets. */
3576 .vector_size = sizeof (u32),
3577 .n_errors = TCP_N_ERROR,
3578 .error_strings = tcp_error_strings,
3579 .n_next_nodes = TCP_INPUT_N_NEXT,
3582 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3583 foreach_tcp4_input_next
3586 .format_buffer = format_tcp_header,
3587 .format_trace = format_tcp_rx_trace,
3591 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3594 VLIB_REGISTER_NODE (tcp6_input_node) =
3596 .function = tcp6_input,
3597 .name = "tcp6-input",
3598 /* Takes a vector of packets. */
3599 .vector_size = sizeof (u32),
3600 .n_errors = TCP_N_ERROR,
3601 .error_strings = tcp_error_strings,
3602 .n_next_nodes = TCP_INPUT_N_NEXT,
3605 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3606 foreach_tcp6_input_next
3609 .format_buffer = format_tcp_header,
3610 .format_trace = format_tcp_rx_trace,
3614 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3617 tcp_dispatch_table_init (tcp_main_t * tm)
3620 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3621 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3623 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3624 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3627 #define _(t,f,n,e) \
3629 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3630 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3633 /* RFC 793: In LISTEN if RST drop and if ACK return RST */
3634 _(LISTEN, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3635 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_ACK_INVALID);
3636 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_INVALID_CONNECTION);
3637 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3638 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3639 TCP_ERROR_ACK_INVALID);
3640 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3641 TCP_ERROR_SEGMENT_INVALID);
3642 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3643 TCP_ERROR_SEGMENT_INVALID);
3644 _(LISTEN, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3645 TCP_ERROR_INVALID_CONNECTION);
3646 _(LISTEN, TCP_FLAG_FIN, TCP_INPUT_NEXT_RESET, TCP_ERROR_SEGMENT_INVALID);
3647 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3648 TCP_ERROR_SEGMENT_INVALID);
3649 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3650 TCP_ERROR_SEGMENT_INVALID);
3651 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3653 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_DROP,
3654 TCP_ERROR_SEGMENT_INVALID);
3655 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3656 TCP_ERROR_SEGMENT_INVALID);
3657 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3658 TCP_ERROR_SEGMENT_INVALID);
3659 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3660 TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3661 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3662 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3663 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3664 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3666 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3667 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3669 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3671 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3672 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3673 _(SYN_RCVD, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3674 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3676 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3678 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3679 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3680 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3682 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3683 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3684 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3685 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3686 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3687 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3688 _(SYN_RCVD, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3689 /* SYN-ACK for a SYN */
3690 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3692 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3693 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3694 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3696 _(SYN_SENT, TCP_FLAG_FIN, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3697 _(SYN_SENT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3699 /* ACK for for established connection -> tcp-established. */
3700 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3701 /* FIN for for established connection -> tcp-established. */
3702 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3703 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3705 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3707 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3708 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3709 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED,
3711 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3712 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3713 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3714 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3715 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3716 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3717 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3718 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3720 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3721 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3723 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3725 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3726 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3727 _(ESTABLISHED, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3728 /* ACK or FIN-ACK to our FIN */
3729 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3730 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3732 /* FIN in reply to our FIN from the other side */
3733 _(FIN_WAIT_1, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3734 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3735 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3737 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3738 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3739 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3740 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3741 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3742 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3743 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3745 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3746 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3747 _(FIN_WAIT_1, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3748 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3750 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3752 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3753 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3754 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3755 _(FIN_WAIT_1, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3757 _(CLOSING, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3758 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3759 _(CLOSING, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3760 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3762 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3764 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3765 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3766 _(CLOSING, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3767 _(CLOSING, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3769 _(CLOSING, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3770 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3772 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3774 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3775 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3776 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3778 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3779 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3780 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3781 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3782 /* FIN confirming that the peer (app) has closed */
3783 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3784 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3785 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3787 _(FIN_WAIT_2, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3788 _(FIN_WAIT_2, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3790 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3791 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3793 _(CLOSE_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3794 _(CLOSE_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3796 _(LAST_ACK, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3797 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3798 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3799 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3801 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3803 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3804 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3805 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3807 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3808 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3809 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3810 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3811 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3812 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3813 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3814 _(LAST_ACK, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3816 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3817 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3819 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3821 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3822 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3823 _(TIME_WAIT, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3824 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3825 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3827 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3828 _(TIME_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3830 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3831 /* RFC793 CLOSED: An incoming segment containing a RST is discarded. An
3832 * incoming segment not containing a RST causes a RST to be sent in
3834 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3835 _(CLOSED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3836 TCP_ERROR_CONNECTION_CLOSED);
3837 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3838 _(CLOSED, TCP_FLAG_SYN, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3839 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3844 static clib_error_t *
3845 tcp_input_init (vlib_main_t * vm)
3847 clib_error_t *error = 0;
3848 tcp_main_t *tm = vnet_get_tcp_main ();
3850 if ((error = vlib_call_init_function (vm, tcp_init)))
3853 /* Initialize dispatch table. */
3854 tcp_dispatch_table_init (tm);
3859 VLIB_INIT_FUNCTION (tcp_input_init);
3862 * fd.io coding-style-patch-verification: ON
3865 * eval: (c-set-style "gnu")