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 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 cong recovery, we reset snd_nxt to snd_una. Seems
1554 * peer still has the data so accept the ack */
1555 if (tcp_in_cong_recovery (tc)
1556 && seq_leq (vnet_buffer (b)->tcp.ack_number,
1557 tc->snd_una + tc->snd_wnd))
1559 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1560 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
1561 tc->snd_una_max = tc->snd_nxt;
1565 /* If we have outstanding data and this is within the window, accept it,
1566 * probably retransmit has timed out. Otherwise ACK segment and then
1568 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1570 tcp_program_ack (wrk, tc);
1571 *error = TCP_ERROR_ACK_FUTURE;
1572 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1573 vnet_buffer (b)->tcp.ack_number);
1577 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1578 vnet_buffer (b)->tcp.ack_number);
1580 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1581 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
1582 tc->snd_una_max = tc->snd_nxt;
1587 /* If old ACK, probably it's an old dupack */
1588 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1590 *error = TCP_ERROR_ACK_OLD;
1591 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1592 vnet_buffer (b)->tcp.ack_number);
1593 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1594 tcp_cc_handle_event (tc, 1);
1595 /* Don't drop yet */
1600 * Looks okay, process feedback
1603 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1604 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1606 prev_snd_wnd = tc->snd_wnd;
1607 prev_snd_una = tc->snd_una;
1608 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1609 vnet_buffer (b)->tcp.ack_number,
1610 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1611 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1612 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1613 tcp_validate_txf_size (tc, tc->bytes_acked);
1615 if (tc->bytes_acked)
1617 tcp_program_dequeue (wrk, tc);
1618 tcp_update_rtt (tc, vnet_buffer (b)->tcp.ack_number);
1621 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1624 * Check if we have congestion event
1627 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1629 tcp_cc_handle_event (tc, is_dack);
1630 if (!tcp_in_cong_recovery (tc))
1632 *error = TCP_ERROR_ACK_OK;
1635 *error = TCP_ERROR_ACK_DUP;
1636 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1642 * Update congestion control (slow start/congestion avoidance)
1644 tcp_cc_update (tc, b);
1645 *error = TCP_ERROR_ACK_OK;
1650 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1652 if (!tcp_disconnect_pending (tc))
1654 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1655 tcp_disconnect_pending_on (tc);
1660 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1662 u32 thread_index, *pending_disconnects;
1663 tcp_connection_t *tc;
1666 if (!vec_len (wrk->pending_disconnects))
1669 thread_index = wrk->vm->thread_index;
1670 pending_disconnects = wrk->pending_disconnects;
1671 for (i = 0; i < vec_len (pending_disconnects); i++)
1673 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1674 tcp_disconnect_pending_off (tc);
1675 session_transport_closing_notify (&tc->connection);
1677 _vec_len (wrk->pending_disconnects) = 0;
1681 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1684 /* Account for the FIN and send ack */
1686 tcp_program_ack (wrk, tc);
1687 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1688 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1689 tcp_connection_set_state (tc, TCP_STATE_CLOSE_WAIT);
1690 tcp_program_disconnect (wrk, tc);
1691 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1692 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc);
1693 *error = TCP_ERROR_FIN_RCVD;
1697 tcp_sack_vector_is_sane (sack_block_t * sacks)
1700 for (i = 1; i < vec_len (sacks); i++)
1702 if (sacks[i - 1].end == sacks[i].start)
1709 * Build SACK list as per RFC2018.
1711 * Makes sure the first block contains the segment that generated the current
1712 * ACK and the following ones are the ones most recently reported in SACK
1715 * @param tc TCP connection for which the SACK list is updated
1716 * @param start Start sequence number of the newest SACK block
1717 * @param end End sequence of the newest SACK block
1720 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1722 sack_block_t *new_list = tc->snd_sacks_fl, *block = 0;
1725 /* If the first segment is ooo add it to the list. Last write might've moved
1726 * rcv_nxt over the first segment. */
1727 if (seq_lt (tc->rcv_nxt, start))
1729 vec_add2 (new_list, block, 1);
1730 block->start = start;
1734 /* Find the blocks still worth keeping. */
1735 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1737 /* Discard if rcv_nxt advanced beyond current block */
1738 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1741 /* Merge or drop if segment overlapped by the new segment */
1742 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1743 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1745 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1746 new_list[0].start = tc->snd_sacks[i].start;
1747 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1748 new_list[0].end = tc->snd_sacks[i].end;
1752 /* Save to new SACK list if we have space. */
1753 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1755 vec_add1 (new_list, tc->snd_sacks[i]);
1759 clib_warning ("sack discarded");
1763 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1765 /* Replace old vector with new one */
1766 vec_reset_length (tc->snd_sacks);
1767 tc->snd_sacks_fl = tc->snd_sacks;
1768 tc->snd_sacks = new_list;
1770 /* Segments should not 'touch' */
1771 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1775 tcp_sack_list_bytes (tcp_connection_t * tc)
1778 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1779 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1783 /** Enqueue data for delivery to application */
1785 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1788 int written, error = TCP_ERROR_ENQUEUED;
1790 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1792 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1793 1 /* queue event */ , 1);
1795 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1797 /* Update rcv_nxt */
1798 if (PREDICT_TRUE (written == data_len))
1800 tc->rcv_nxt += written;
1802 /* If more data written than expected, account for out-of-order bytes. */
1803 else if (written > data_len)
1805 tc->rcv_nxt += written;
1806 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1808 else if (written > 0)
1810 /* We've written something but FIFO is probably full now */
1811 tc->rcv_nxt += written;
1812 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1816 return TCP_ERROR_FIFO_FULL;
1819 /* Update SACK list if need be */
1820 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1822 /* Remove SACK blocks that have been delivered */
1823 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1829 /** Enqueue out-of-order data */
1831 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1837 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1840 /* Enqueue out-of-order data with relative offset */
1841 rv = session_enqueue_stream_connection (&tc->connection, b,
1842 vnet_buffer (b)->tcp.seq_number -
1843 tc->rcv_nxt, 0 /* queue event */ ,
1846 /* Nothing written */
1849 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1850 return TCP_ERROR_FIFO_FULL;
1853 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1855 /* Update SACK list if in use */
1856 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1858 ooo_segment_t *newest;
1861 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1863 /* Get the newest segment from the fifo */
1864 newest = svm_fifo_newest_ooo_segment (s0->rx_fifo);
1867 offset = ooo_segment_offset (s0->rx_fifo, newest);
1868 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1869 start = tc->rcv_nxt + offset;
1870 end = start + ooo_segment_length (s0->rx_fifo, newest);
1871 tcp_update_sack_list (tc, start, end);
1872 svm_fifo_newest_ooo_segment_reset (s0->rx_fifo);
1873 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1877 return TCP_ERROR_ENQUEUED_OOO;
1881 * Check if ACK could be delayed. If ack can be delayed, it should return
1882 * true for a full frame. If we're always acking return 0.
1885 tcp_can_delack (tcp_connection_t * tc)
1887 /* Send ack if ... */
1889 /* just sent a rcv wnd 0 */
1890 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1891 /* constrained to send ack */
1892 || (tc->flags & TCP_CONN_SNDACK) != 0
1893 /* we're almost out of tx wnd */
1894 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1901 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1903 u32 discard, first = b->current_length;
1904 vlib_main_t *vm = vlib_get_main ();
1906 /* Handle multi-buffer segments */
1907 if (n_bytes_to_drop > b->current_length)
1909 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1913 discard = clib_min (n_bytes_to_drop, b->current_length);
1914 vlib_buffer_advance (b, discard);
1915 b = vlib_get_buffer (vm, b->next_buffer);
1916 n_bytes_to_drop -= discard;
1918 while (n_bytes_to_drop);
1919 if (n_bytes_to_drop > first)
1920 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1923 vlib_buffer_advance (b, n_bytes_to_drop);
1924 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1929 * Receive buffer for connection and handle acks
1931 * It handles both in order or out-of-order data.
1934 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1937 u32 error, n_bytes_to_drop, n_data_bytes;
1939 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1940 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1941 ASSERT (n_data_bytes);
1943 /* Handle out-of-order data */
1944 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1946 /* Old sequence numbers allowed through because they overlapped
1948 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1950 /* Completely in the past (possible retransmit). Ack
1951 * retransmissions since we may not have any data to send */
1952 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1954 tcp_program_ack (wrk, tc);
1955 error = TCP_ERROR_SEGMENT_OLD;
1959 /* Chop off the bytes in the past and see if what is left
1960 * can be enqueued in order */
1961 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1962 n_data_bytes -= n_bytes_to_drop;
1963 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1964 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1966 error = TCP_ERROR_SEGMENT_OLD;
1972 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1973 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1974 tcp_program_dupack (wrk, tc);
1975 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1981 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1982 * segments can be enqueued after fifo tail offset changes. */
1983 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1984 if (tcp_can_delack (tc))
1986 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1987 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1991 tcp_program_ack (wrk, tc);
1999 tcp_header_t tcp_header;
2000 tcp_connection_t tcp_connection;
2004 format_tcp_rx_trace (u8 * s, va_list * args)
2006 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2007 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2008 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2009 u32 indent = format_get_indent (s);
2011 s = format (s, "%U\n%U%U",
2012 format_tcp_header, &t->tcp_header, 128,
2013 format_white_space, indent,
2014 format_tcp_connection, &t->tcp_connection, 1);
2020 format_tcp_rx_trace_short (u8 * s, va_list * args)
2022 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2023 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2024 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2026 s = format (s, "%d -> %d (%U)",
2027 clib_net_to_host_u16 (t->tcp_header.dst_port),
2028 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
2029 t->tcp_connection.state);
2035 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
2036 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
2040 clib_memcpy_fast (&t0->tcp_connection, tc0,
2041 sizeof (t0->tcp_connection));
2045 th0 = tcp_buffer_hdr (b0);
2047 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2051 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2052 vlib_frame_t * frame, u8 is_ip4)
2056 n_left = frame->n_vectors;
2057 from = vlib_frame_vector_args (frame);
2061 tcp_connection_t *tc0;
2068 b0 = vlib_get_buffer (vm, bi0);
2070 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2072 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2073 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2075 th0 = tcp_buffer_hdr (b0);
2076 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2085 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2086 u8 is_ip4, u32 evt, u32 val)
2089 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2091 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2094 #define tcp_maybe_inc_counter(node_id, err, count) \
2096 if (next0 != tcp_next_drop (is_ip4)) \
2097 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2098 tcp6_##node_id##_node.index, is_ip4, err, \
2101 #define tcp_inc_counter(node_id, err, count) \
2102 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2103 tcp6_##node_id##_node.index, is_ip4, \
2105 #define tcp_maybe_inc_err_counter(cnts, err) \
2107 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2109 #define tcp_inc_err_counter(cnts, err, val) \
2113 #define tcp_store_err_counters(node_id, cnts) \
2116 for (i = 0; i < TCP_N_ERROR; i++) \
2118 tcp_inc_counter(node_id, i, cnts[i]); \
2123 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2124 vlib_frame_t * frame, int is_ip4)
2126 u32 thread_index = vm->thread_index, errors = 0;
2127 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2128 u32 n_left_from, *from, *first_buffer;
2129 u16 err_counters[TCP_N_ERROR] = { 0 };
2131 if (node->flags & VLIB_NODE_FLAG_TRACE)
2132 tcp_established_trace_frame (vm, node, frame, is_ip4);
2134 first_buffer = from = vlib_frame_vector_args (frame);
2135 n_left_from = frame->n_vectors;
2137 while (n_left_from > 0)
2139 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2142 tcp_connection_t *tc0;
2144 if (n_left_from > 1)
2147 pb = vlib_get_buffer (vm, from[1]);
2148 vlib_prefetch_buffer_header (pb, LOAD);
2149 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2156 b0 = vlib_get_buffer (vm, bi0);
2157 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2160 if (PREDICT_FALSE (tc0 == 0))
2162 error0 = TCP_ERROR_INVALID_CONNECTION;
2166 th0 = tcp_buffer_hdr (b0);
2168 /* TODO header prediction fast path */
2170 /* 1-4: check SEQ, RST, SYN */
2171 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2173 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2177 /* 5: check the ACK field */
2178 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2181 /* 6: check the URG bit TODO */
2183 /* 7: process the segment text */
2184 if (vnet_buffer (b0)->tcp.data_len)
2185 error0 = tcp_segment_rcv (wrk, tc0, b0);
2187 /* 8: check the FIN bit */
2188 if (PREDICT_FALSE (tcp_is_fin (th0)))
2189 tcp_rcv_fin (wrk, tc0, b0, &error0);
2192 tcp_inc_err_counter (err_counters, error0, 1);
2195 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2197 err_counters[TCP_ERROR_MSG_QUEUE_FULL] = errors;
2198 tcp_store_err_counters (established, err_counters);
2199 tcp_handle_postponed_dequeues (wrk);
2200 tcp_handle_disconnects (wrk);
2201 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2203 return frame->n_vectors;
2207 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2208 vlib_frame_t * from_frame)
2210 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2214 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2215 vlib_frame_t * from_frame)
2217 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2221 VLIB_REGISTER_NODE (tcp4_established_node) =
2223 .function = tcp4_established,
2224 .name = "tcp4-established",
2225 /* Takes a vector of packets. */
2226 .vector_size = sizeof (u32),
2227 .n_errors = TCP_N_ERROR,
2228 .error_strings = tcp_error_strings,
2229 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2232 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2233 foreach_tcp_state_next
2236 .format_trace = format_tcp_rx_trace_short,
2240 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
2243 VLIB_REGISTER_NODE (tcp6_established_node) =
2245 .function = tcp6_established,
2246 .name = "tcp6-established",
2247 /* Takes a vector of packets. */
2248 .vector_size = sizeof (u32),
2249 .n_errors = TCP_N_ERROR,
2250 .error_strings = tcp_error_strings,
2251 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2254 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2255 foreach_tcp_state_next
2258 .format_trace = format_tcp_rx_trace_short,
2263 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
2265 vlib_node_registration_t tcp4_syn_sent_node;
2266 vlib_node_registration_t tcp6_syn_sent_node;
2269 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2271 transport_connection_t *tmp = 0;
2278 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2281 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2282 && (tc->state == TCP_STATE_LISTEN
2283 || tc->c_rmt_port == hdr->src_port));
2287 handle = session_lookup_half_open_handle (&tc->connection);
2288 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2289 tc->c_proto, tc->c_is_ip4);
2293 if (tmp->lcl_port == hdr->dst_port
2294 && tmp->rmt_port == hdr->src_port)
2296 TCP_DBG ("half-open is valid!");
2304 * Lookup transport connection
2306 static tcp_connection_t *
2307 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2311 transport_connection_t *tconn;
2312 tcp_connection_t *tc;
2317 ip4 = vlib_buffer_get_current (b);
2318 tcp = ip4_next_header (ip4);
2319 tconn = session_lookup_connection_wt4 (fib_index,
2324 TRANSPORT_PROTO_TCP,
2325 thread_index, &is_filtered);
2326 tc = tcp_get_connection_from_transport (tconn);
2327 ASSERT (tcp_lookup_is_valid (tc, tcp));
2332 ip6 = vlib_buffer_get_current (b);
2333 tcp = ip6_next_header (ip6);
2334 tconn = session_lookup_connection_wt6 (fib_index,
2339 TRANSPORT_PROTO_TCP,
2340 thread_index, &is_filtered);
2341 tc = tcp_get_connection_from_transport (tconn);
2342 ASSERT (tcp_lookup_is_valid (tc, tcp));
2348 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2349 vlib_frame_t * from_frame, int is_ip4)
2351 tcp_main_t *tm = vnet_get_tcp_main ();
2352 u32 n_left_from, *from, *first_buffer, errors = 0;
2353 u32 my_thread_index = vm->thread_index;
2354 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2356 from = first_buffer = vlib_frame_vector_args (from_frame);
2357 n_left_from = from_frame->n_vectors;
2359 while (n_left_from > 0)
2361 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2362 tcp_connection_t *tc0, *new_tc0;
2363 tcp_header_t *tcp0 = 0;
2371 b0 = vlib_get_buffer (vm, bi0);
2373 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2374 if (PREDICT_FALSE (tc0 == 0))
2376 error0 = TCP_ERROR_INVALID_CONNECTION;
2380 /* Half-open completed recently but the connection was't removed
2381 * yet by the owning thread */
2382 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2384 /* Make sure the connection actually exists */
2385 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2386 my_thread_index, is_ip4));
2387 error0 = TCP_ERROR_SPURIOUS_SYN_ACK;
2391 ack0 = vnet_buffer (b0)->tcp.ack_number;
2392 seq0 = vnet_buffer (b0)->tcp.seq_number;
2393 tcp0 = tcp_buffer_hdr (b0);
2395 /* Crude check to see if the connection handle does not match
2396 * the packet. Probably connection just switched to established */
2397 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2398 || tcp0->src_port != tc0->c_rmt_port))
2400 error0 = TCP_ERROR_INVALID_CONNECTION;
2404 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2405 && !tcp_syn (tcp0)))
2407 error0 = TCP_ERROR_SEGMENT_INVALID;
2411 /* SYNs consume sequence numbers */
2412 vnet_buffer (b0)->tcp.seq_end += tcp_is_syn (tcp0);
2415 * 1. check the ACK bit
2419 * If the ACK bit is set
2420 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2421 * the RST bit is set, if so drop the segment and return)
2422 * <SEQ=SEG.ACK><CTL=RST>
2423 * and discard the segment. Return.
2424 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2428 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2430 if (!tcp_rst (tcp0))
2431 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2432 error0 = TCP_ERROR_RCV_WND;
2436 /* Make sure ACK is valid */
2437 if (seq_gt (tc0->snd_una, ack0))
2439 error0 = TCP_ERROR_ACK_INVALID;
2445 * 2. check the RST bit
2450 /* If ACK is acceptable, signal client that peer is not
2451 * willing to accept connection and drop connection*/
2453 tcp_connection_reset (tc0);
2454 error0 = TCP_ERROR_RST_RCVD;
2459 * 3. check the security and precedence (skipped)
2463 * 4. check the SYN bit
2466 /* No SYN flag. Drop. */
2467 if (!tcp_syn (tcp0))
2469 error0 = TCP_ERROR_SEGMENT_INVALID;
2474 if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1))
2476 error0 = TCP_ERROR_OPTIONS;
2480 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2481 * current thread pool. */
2482 pool_get (tm->connections[my_thread_index], new_tc0);
2483 clib_memcpy_fast (new_tc0, tc0, sizeof (*new_tc0));
2484 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2485 new_tc0->c_thread_index = my_thread_index;
2486 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2487 new_tc0->irs = seq0;
2488 new_tc0->timers[TCP_TIMER_ESTABLISH_AO] = TCP_TIMER_HANDLE_INVALID;
2489 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2490 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2492 /* If this is not the owning thread, wait for syn retransmit to
2493 * expire and cleanup then */
2494 if (tcp_half_open_connection_cleanup (tc0))
2495 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2497 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2499 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2500 new_tc0->tsval_recent_age = tcp_time_now ();
2503 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2504 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2506 new_tc0->rcv_wscale = 0;
2508 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2509 << new_tc0->snd_wscale;
2510 new_tc0->snd_wl1 = seq0;
2511 new_tc0->snd_wl2 = ack0;
2513 tcp_connection_init_vars (new_tc0);
2515 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2516 if (PREDICT_TRUE (tcp_ack (tcp0)))
2518 /* Our SYN is ACKed: we have iss < ack = snd_una */
2520 /* TODO Dequeue acknowledged segments if we support Fast Open */
2521 new_tc0->snd_una = ack0;
2522 new_tc0->state = TCP_STATE_ESTABLISHED;
2524 /* Make sure las is initialized for the wnd computation */
2525 new_tc0->rcv_las = new_tc0->rcv_nxt;
2527 /* Notify app that we have connection. If session layer can't
2528 * allocate session send reset */
2529 if (session_stream_connect_notify (&new_tc0->connection, 0))
2531 clib_warning ("connect notify fail");
2532 tcp_send_reset_w_pkt (new_tc0, b0, my_thread_index, is_ip4);
2533 tcp_connection_cleanup (new_tc0);
2537 new_tc0->tx_fifo_size =
2538 transport_tx_fifo_size (&new_tc0->connection);
2539 /* Update rtt with the syn-ack sample */
2540 tcp_estimate_initial_rtt (new_tc0);
2541 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2542 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2544 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2547 new_tc0->state = TCP_STATE_SYN_RCVD;
2549 /* Notify app that we have connection */
2550 if (session_stream_connect_notify (&new_tc0->connection, 0))
2552 tcp_connection_cleanup (new_tc0);
2553 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2554 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2558 new_tc0->tx_fifo_size =
2559 transport_tx_fifo_size (&new_tc0->connection);
2560 new_tc0->rtt_ts = 0;
2561 tcp_init_snd_vars (new_tc0);
2562 tcp_send_synack (new_tc0);
2563 error0 = TCP_ERROR_SYNS_RCVD;
2567 /* Read data, if any */
2568 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2570 clib_warning ("rcvd data in syn-sent");
2571 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2572 if (error0 == TCP_ERROR_ACK_OK)
2573 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2577 tcp_program_ack (wrk, new_tc0);
2582 tcp_inc_counter (syn_sent, error0, 1);
2583 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2585 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2586 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2587 clib_memcpy_fast (&t0->tcp_connection, tc0,
2588 sizeof (t0->tcp_connection));
2592 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2594 tcp_inc_counter (syn_sent, TCP_ERROR_MSG_QUEUE_FULL, errors);
2595 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2597 return from_frame->n_vectors;
2601 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2602 vlib_frame_t * from_frame)
2604 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2608 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2609 vlib_frame_t * from_frame)
2611 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2615 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2617 .function = tcp4_syn_sent,
2618 .name = "tcp4-syn-sent",
2619 /* Takes a vector of packets. */
2620 .vector_size = sizeof (u32),
2621 .n_errors = TCP_N_ERROR,
2622 .error_strings = tcp_error_strings,
2623 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2626 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2627 foreach_tcp_state_next
2630 .format_trace = format_tcp_rx_trace_short,
2634 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2637 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2639 .function = tcp6_syn_sent_rcv,
2640 .name = "tcp6-syn-sent",
2641 /* Takes a vector of packets. */
2642 .vector_size = sizeof (u32),
2643 .n_errors = TCP_N_ERROR,
2644 .error_strings = tcp_error_strings,
2645 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2648 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2649 foreach_tcp_state_next
2652 .format_trace = format_tcp_rx_trace_short,
2656 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2658 vlib_node_registration_t tcp4_rcv_process_node;
2659 vlib_node_registration_t tcp6_rcv_process_node;
2662 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2663 * as per RFC793 p. 64
2666 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2667 vlib_frame_t * from_frame, int is_ip4)
2669 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2670 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2671 u32 n_left_from, *from, max_dequeue;
2673 from = first_buffer = vlib_frame_vector_args (from_frame);
2674 n_left_from = from_frame->n_vectors;
2676 while (n_left_from > 0)
2678 u32 bi0, error0 = TCP_ERROR_NONE;
2679 tcp_header_t *tcp0 = 0;
2680 tcp_connection_t *tc0;
2688 b0 = vlib_get_buffer (vm, bi0);
2689 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2691 if (PREDICT_FALSE (tc0 == 0))
2693 error0 = TCP_ERROR_INVALID_CONNECTION;
2697 tcp0 = tcp_buffer_hdr (b0);
2698 is_fin0 = tcp_is_fin (tcp0);
2702 tcp_connection_t *tmp;
2703 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2705 if (tmp->state != tc0->state)
2707 if (tc0->state != TCP_STATE_CLOSED)
2708 clib_warning ("state changed");
2714 * Special treatment for CLOSED
2716 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2718 error0 = TCP_ERROR_CONNECTION_CLOSED;
2723 * For all other states (except LISTEN)
2726 /* 1-4: check SEQ, RST, SYN */
2727 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2730 /* 5: check the ACK field */
2733 case TCP_STATE_SYN_RCVD:
2735 * If the segment acknowledgment is not acceptable, form a
2737 * <SEQ=SEG.ACK><CTL=RST>
2740 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2742 tcp_connection_reset (tc0);
2743 error0 = TCP_ERROR_ACK_INVALID;
2747 /* Make sure the ack is exactly right */
2748 if (tc0->rcv_nxt != vnet_buffer (b0)->tcp.seq_number || is_fin0)
2750 tcp_connection_reset (tc0);
2751 error0 = TCP_ERROR_SEGMENT_INVALID;
2755 /* Update rtt and rto */
2756 tcp_estimate_initial_rtt (tc0);
2758 /* Switch state to ESTABLISHED */
2759 tc0->state = TCP_STATE_ESTABLISHED;
2760 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2762 /* Initialize session variables */
2763 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2764 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2765 << tc0->rcv_opts.wscale;
2766 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2767 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2769 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2770 tcp_retransmit_timer_reset (tc0);
2771 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2772 if (session_stream_accept_notify (&tc0->connection))
2774 error0 = TCP_ERROR_MSG_QUEUE_FULL;
2775 tcp_connection_reset (tc0);
2778 error0 = TCP_ERROR_ACK_OK;
2780 case TCP_STATE_ESTABLISHED:
2781 /* We can get packets in established state here because they
2782 * were enqueued before state change */
2783 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2787 case TCP_STATE_FIN_WAIT_1:
2788 /* In addition to the processing for the ESTABLISHED state, if
2789 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2790 * continue processing in that state. */
2791 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2794 /* Still have to send the FIN */
2795 if (tc0->flags & TCP_CONN_FINPNDG)
2797 /* TX fifo finally drained */
2798 max_dequeue = session_tx_fifo_max_dequeue (&tc0->connection);
2799 if (max_dequeue <= tc0->burst_acked)
2802 /* If FIN is ACKed */
2803 else if (tc0->snd_una == tc0->snd_una_max)
2805 tcp_connection_set_state (tc0, TCP_STATE_FIN_WAIT_2);
2807 /* Stop all retransmit timers because we have nothing more
2808 * to send. Enable waitclose though because we're willing to
2809 * wait for peer's FIN but not indefinitely. */
2810 tcp_connection_timers_reset (tc0);
2811 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2813 /* Don't try to deq the FIN acked */
2814 if (tc0->burst_acked > 1)
2815 session_dequeue_drop (&tc0->connection, tc0->burst_acked - 1);
2816 tc0->burst_acked = 0;
2819 case TCP_STATE_FIN_WAIT_2:
2820 /* In addition to the processing for the ESTABLISHED state, if
2821 * the retransmission queue is empty, the user's CLOSE can be
2822 * acknowledged ("ok") but do not delete the TCB. */
2823 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2825 tc0->burst_acked = 0;
2827 case TCP_STATE_CLOSE_WAIT:
2828 /* Do the same processing as for the ESTABLISHED state. */
2829 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2832 if (tc0->flags & TCP_CONN_FINPNDG)
2834 /* TX fifo finally drained */
2835 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2838 tcp_connection_timers_reset (tc0);
2839 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2840 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2844 case TCP_STATE_CLOSING:
2845 /* In addition to the processing for the ESTABLISHED state, if
2846 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2847 * otherwise ignore the segment. */
2848 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2851 tcp_connection_timers_reset (tc0);
2852 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2853 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2857 case TCP_STATE_LAST_ACK:
2858 /* The only thing that [should] arrive in this state is an
2859 * acknowledgment of our FIN. If our FIN is now acknowledged,
2860 * delete the TCB, enter the CLOSED state, and return. */
2862 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2864 error0 = TCP_ERROR_ACK_INVALID;
2867 error0 = TCP_ERROR_ACK_OK;
2868 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2869 /* Apparently our ACK for the peer's FIN was lost */
2870 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2876 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2878 /* Don't free the connection from the data path since
2879 * we can't ensure that we have no packets already enqueued
2880 * to output. Rely instead on the waitclose timer */
2881 tcp_connection_timers_reset (tc0);
2882 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2887 case TCP_STATE_TIME_WAIT:
2888 /* The only thing that can arrive in this state is a
2889 * retransmission of the remote FIN. Acknowledge it, and restart
2890 * the 2 MSL timeout. */
2892 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2895 tcp_program_ack (wrk, tc0);
2896 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2904 /* 6: check the URG bit TODO */
2906 /* 7: process the segment text */
2909 case TCP_STATE_ESTABLISHED:
2910 case TCP_STATE_FIN_WAIT_1:
2911 case TCP_STATE_FIN_WAIT_2:
2912 if (vnet_buffer (b0)->tcp.data_len)
2913 error0 = tcp_segment_rcv (wrk, tc0, b0);
2915 case TCP_STATE_CLOSE_WAIT:
2916 case TCP_STATE_CLOSING:
2917 case TCP_STATE_LAST_ACK:
2918 case TCP_STATE_TIME_WAIT:
2919 /* This should not occur, since a FIN has been received from the
2920 * remote side. Ignore the segment text. */
2924 /* 8: check the FIN bit */
2928 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2932 case TCP_STATE_ESTABLISHED:
2933 /* Account for the FIN and send ack */
2935 tcp_program_ack (wrk, tc0);
2936 tcp_connection_set_state (tc0, TCP_STATE_CLOSE_WAIT);
2937 tcp_program_disconnect (wrk, tc0);
2938 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
2940 case TCP_STATE_SYN_RCVD:
2941 /* Send FIN-ACK, enter LAST-ACK and because the app was not
2942 * notified yet, set a cleanup timer instead of relying on
2943 * disconnect notify and the implicit close call. */
2944 tcp_connection_timers_reset (tc0);
2947 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2948 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2950 case TCP_STATE_CLOSE_WAIT:
2951 case TCP_STATE_CLOSING:
2952 case TCP_STATE_LAST_ACK:
2955 case TCP_STATE_FIN_WAIT_1:
2957 tcp_connection_set_state (tc0, TCP_STATE_CLOSING);
2958 if (tc0->flags & TCP_CONN_FINPNDG)
2960 /* Drop all outstanding tx data. */
2961 session_dequeue_drop (&tc0->connection,
2962 transport_max_tx_dequeue
2963 (&tc0->connection));
2967 tcp_program_ack (wrk, tc0);
2968 /* Wait for ACK for our FIN but not forever */
2969 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2971 case TCP_STATE_FIN_WAIT_2:
2972 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2974 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2975 tcp_connection_timers_reset (tc0);
2976 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2977 tcp_program_ack (wrk, tc0);
2979 case TCP_STATE_TIME_WAIT:
2980 /* Remain in the TIME-WAIT state. Restart the time-wait
2983 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2986 error0 = TCP_ERROR_FIN_RCVD;
2990 tcp_inc_counter (rcv_process, error0, 1);
2991 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2993 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2994 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2998 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
3000 tcp_inc_counter (rcv_process, TCP_ERROR_MSG_QUEUE_FULL, errors);
3001 tcp_handle_postponed_dequeues (wrk);
3002 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3004 return from_frame->n_vectors;
3008 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
3009 vlib_frame_t * from_frame)
3011 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3015 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
3016 vlib_frame_t * from_frame)
3018 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3022 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
3024 .function = tcp4_rcv_process,
3025 .name = "tcp4-rcv-process",
3026 /* Takes a vector of packets. */
3027 .vector_size = sizeof (u32),
3028 .n_errors = TCP_N_ERROR,
3029 .error_strings = tcp_error_strings,
3030 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3033 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3034 foreach_tcp_state_next
3037 .format_trace = format_tcp_rx_trace_short,
3041 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
3044 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
3046 .function = tcp6_rcv_process,
3047 .name = "tcp6-rcv-process",
3048 /* Takes a vector of packets. */
3049 .vector_size = sizeof (u32),
3050 .n_errors = TCP_N_ERROR,
3051 .error_strings = tcp_error_strings,
3052 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3055 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3056 foreach_tcp_state_next
3059 .format_trace = format_tcp_rx_trace_short,
3063 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
3065 vlib_node_registration_t tcp4_listen_node;
3066 vlib_node_registration_t tcp6_listen_node;
3069 * LISTEN state processing as per RFC 793 p. 65
3072 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3073 vlib_frame_t * from_frame, int is_ip4)
3075 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3076 u32 my_thread_index = vm->thread_index;
3078 from = first_buffer = vlib_frame_vector_args (from_frame);
3079 n_left_from = from_frame->n_vectors;
3081 while (n_left_from > 0)
3086 tcp_header_t *th0 = 0;
3087 tcp_connection_t *lc0;
3090 tcp_connection_t *child0;
3091 u32 error0 = TCP_ERROR_NONE;
3097 b0 = vlib_get_buffer (vm, bi0);
3098 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3102 ip40 = vlib_buffer_get_current (b0);
3103 th0 = ip4_next_header (ip40);
3107 ip60 = vlib_buffer_get_current (b0);
3108 th0 = ip6_next_header (ip60);
3111 /* Create child session. For syn-flood protection use filter */
3113 /* 1. first check for an RST: handled in dispatch */
3114 /* if (tcp_rst (th0))
3118 /* 2. second check for an ACK: handled in dispatch */
3119 /* if (tcp_ack (th0))
3121 tcp_send_reset (b0, is_ip4);
3126 /* 3. check for a SYN (did that already) */
3128 /* Make sure connection wasn't just created */
3129 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3131 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3133 error0 = TCP_ERROR_CREATE_EXISTS;
3137 /* Create child session and send SYN-ACK */
3138 child0 = tcp_connection_alloc (my_thread_index);
3139 child0->c_lcl_port = th0->dst_port;
3140 child0->c_rmt_port = th0->src_port;
3141 child0->c_is_ip4 = is_ip4;
3142 child0->state = TCP_STATE_SYN_RCVD;
3143 child0->c_fib_index = lc0->c_fib_index;
3147 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3148 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3152 clib_memcpy_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3153 sizeof (ip6_address_t));
3154 clib_memcpy_fast (&child0->c_rmt_ip6, &ip60->src_address,
3155 sizeof (ip6_address_t));
3158 if (tcp_options_parse (th0, &child0->rcv_opts, 1))
3160 error0 = TCP_ERROR_OPTIONS;
3161 tcp_connection_free (child0);
3165 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3166 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3167 child0->rcv_las = child0->rcv_nxt;
3168 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3170 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3171 * segments are used to initialize PAWS. */
3172 if (tcp_opts_tstamp (&child0->rcv_opts))
3174 child0->tsval_recent = child0->rcv_opts.tsval;
3175 child0->tsval_recent_age = tcp_time_now ();
3178 if (tcp_opts_wscale (&child0->rcv_opts))
3179 child0->snd_wscale = child0->rcv_opts.wscale;
3181 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3182 << child0->snd_wscale;
3183 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3184 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3186 tcp_connection_init_vars (child0);
3187 child0->rto = TCP_RTO_MIN;
3188 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
3190 if (session_stream_accept (&child0->connection, lc0->c_s_index,
3193 tcp_connection_cleanup (child0);
3194 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3198 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3199 tcp_send_synack (child0);
3200 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
3204 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3206 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3207 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3208 clib_memcpy_fast (&t0->tcp_connection, lc0,
3209 sizeof (t0->tcp_connection));
3212 n_syns += (error0 == TCP_ERROR_NONE);
3215 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3216 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3218 return from_frame->n_vectors;
3222 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3223 vlib_frame_t * from_frame)
3225 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3229 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3230 vlib_frame_t * from_frame)
3232 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3236 VLIB_REGISTER_NODE (tcp4_listen_node) =
3238 .function = tcp4_listen,
3239 .name = "tcp4-listen",
3240 /* Takes a vector of packets. */
3241 .vector_size = sizeof (u32),
3242 .n_errors = TCP_N_ERROR,
3243 .error_strings = tcp_error_strings,
3244 .n_next_nodes = TCP_LISTEN_N_NEXT,
3247 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3248 foreach_tcp_state_next
3251 .format_trace = format_tcp_rx_trace_short,
3255 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
3258 VLIB_REGISTER_NODE (tcp6_listen_node) =
3260 .function = tcp6_listen,
3261 .name = "tcp6-listen",
3262 /* Takes a vector of packets. */
3263 .vector_size = sizeof (u32),
3264 .n_errors = TCP_N_ERROR,
3265 .error_strings = tcp_error_strings,
3266 .n_next_nodes = TCP_LISTEN_N_NEXT,
3269 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3270 foreach_tcp_state_next
3273 .format_trace = format_tcp_rx_trace_short,
3277 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
3279 vlib_node_registration_t tcp4_input_node;
3280 vlib_node_registration_t tcp6_input_node;
3282 typedef enum _tcp_input_next
3284 TCP_INPUT_NEXT_DROP,
3285 TCP_INPUT_NEXT_LISTEN,
3286 TCP_INPUT_NEXT_RCV_PROCESS,
3287 TCP_INPUT_NEXT_SYN_SENT,
3288 TCP_INPUT_NEXT_ESTABLISHED,
3289 TCP_INPUT_NEXT_RESET,
3290 TCP_INPUT_NEXT_PUNT,
3294 #define foreach_tcp4_input_next \
3295 _ (DROP, "ip4-drop") \
3296 _ (LISTEN, "tcp4-listen") \
3297 _ (RCV_PROCESS, "tcp4-rcv-process") \
3298 _ (SYN_SENT, "tcp4-syn-sent") \
3299 _ (ESTABLISHED, "tcp4-established") \
3300 _ (RESET, "tcp4-reset") \
3301 _ (PUNT, "ip4-punt")
3303 #define foreach_tcp6_input_next \
3304 _ (DROP, "ip6-drop") \
3305 _ (LISTEN, "tcp6-listen") \
3306 _ (RCV_PROCESS, "tcp6-rcv-process") \
3307 _ (SYN_SENT, "tcp6-syn-sent") \
3308 _ (ESTABLISHED, "tcp6-established") \
3309 _ (RESET, "tcp6-reset") \
3310 _ (PUNT, "ip6-punt")
3312 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3315 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3316 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3318 tcp_connection_t *tc;
3323 for (i = 0; i < n_bufs; i++)
3325 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3327 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3328 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3330 tcp = vlib_buffer_get_current (bs[i]);
3331 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3337 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3339 if (*error == TCP_ERROR_FILTERED || *error == TCP_ERROR_WRONG_THREAD)
3341 *next = TCP_INPUT_NEXT_DROP;
3343 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3345 *next = TCP_INPUT_NEXT_PUNT;
3346 *error = TCP_ERROR_PUNT;
3350 *next = TCP_INPUT_NEXT_RESET;
3351 *error = TCP_ERROR_NO_LISTENER;
3355 static inline tcp_connection_t *
3356 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3359 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3360 int n_advance_bytes, n_data_bytes;
3361 transport_connection_t *tc;
3367 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3368 int ip_hdr_bytes = ip4_header_bytes (ip4);
3369 if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
3371 *error = TCP_ERROR_LENGTH;
3374 tcp = ip4_next_header (ip4);
3375 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3376 n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
3377 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3379 /* Length check. Checksum computed by ipx_local no need to compute again */
3380 if (PREDICT_FALSE (n_data_bytes < 0))
3382 *error = TCP_ERROR_LENGTH;
3386 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3387 &ip4->src_address, tcp->dst_port,
3388 tcp->src_port, TRANSPORT_PROTO_TCP,
3389 thread_index, &result);
3393 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3394 if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
3396 *error = TCP_ERROR_LENGTH;
3399 tcp = ip6_next_header (ip6);
3400 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3401 n_advance_bytes = tcp_header_bytes (tcp);
3402 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3404 n_advance_bytes += sizeof (ip6[0]);
3406 if (PREDICT_FALSE (n_data_bytes < 0))
3408 *error = TCP_ERROR_LENGTH;
3412 (ip6_address_is_link_local_unicast (&ip6->dst_address)))
3414 ip4_main_t *im = &ip4_main;
3415 fib_index = vec_elt (im->fib_index_by_sw_if_index,
3416 vnet_buffer (b)->sw_if_index[VLIB_RX]);
3419 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3420 &ip6->src_address, tcp->dst_port,
3421 tcp->src_port, TRANSPORT_PROTO_TCP,
3422 thread_index, &result);
3425 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3426 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3427 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3428 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3429 vnet_buffer (b)->tcp.seq_end = vnet_buffer (b)->tcp.seq_number
3431 vnet_buffer (b)->tcp.flags = 0;
3433 *error = result ? TCP_ERROR_NONE + result : *error;
3435 return tcp_get_connection_from_transport (tc);
3439 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3440 vlib_buffer_t * b, u16 * next, u32 * error)
3445 tcp = tcp_buffer_hdr (b);
3446 flags = tcp->flags & filter_flags;
3447 *next = tm->dispatch_table[tc->state][flags].next;
3448 *error = tm->dispatch_table[tc->state][flags].error;
3450 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3451 || *next == TCP_INPUT_NEXT_RESET))
3453 /* Overload tcp flags to store state */
3454 tcp_state_t state = tc->state;
3455 vnet_buffer (b)->tcp.flags = tc->state;
3457 if (*error == TCP_ERROR_DISPATCH)
3458 clib_warning ("tcp conn %u disp error state %U flags %U",
3459 tc->c_c_index, format_tcp_state, state,
3460 format_tcp_flags, (int) flags);
3465 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3466 vlib_frame_t * frame, int is_ip4)
3468 u32 n_left_from, *from, thread_index = vm->thread_index;
3469 tcp_main_t *tm = vnet_get_tcp_main ();
3470 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3471 u16 nexts[VLIB_FRAME_SIZE], *next;
3473 tcp_set_time_now (tcp_get_worker (thread_index));
3475 from = vlib_frame_vector_args (frame);
3476 n_left_from = frame->n_vectors;
3477 vlib_get_buffers (vm, from, bufs, n_left_from);
3482 while (n_left_from >= 4)
3484 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3485 tcp_connection_t *tc0, *tc1;
3488 vlib_prefetch_buffer_header (b[2], STORE);
3489 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3491 vlib_prefetch_buffer_header (b[3], STORE);
3492 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3495 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3497 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3498 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4);
3500 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3502 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3503 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3505 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3506 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3508 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3509 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3513 if (PREDICT_TRUE (tc0 != 0))
3515 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3516 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3517 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3520 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3522 if (PREDICT_TRUE (tc1 != 0))
3524 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3525 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3526 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3529 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3536 while (n_left_from > 0)
3538 tcp_connection_t *tc0;
3539 u32 error0 = TCP_ERROR_NO_LISTENER;
3541 if (n_left_from > 1)
3543 vlib_prefetch_buffer_header (b[1], STORE);
3544 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3547 next[0] = TCP_INPUT_NEXT_DROP;
3548 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3549 if (PREDICT_TRUE (tc0 != 0))
3551 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3552 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3553 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3556 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3563 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3564 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3566 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3567 return frame->n_vectors;
3571 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3572 vlib_frame_t * from_frame)
3574 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3578 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3579 vlib_frame_t * from_frame)
3581 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3585 VLIB_REGISTER_NODE (tcp4_input_node) =
3587 .function = tcp4_input,
3588 .name = "tcp4-input",
3589 /* Takes a vector of packets. */
3590 .vector_size = sizeof (u32),
3591 .n_errors = TCP_N_ERROR,
3592 .error_strings = tcp_error_strings,
3593 .n_next_nodes = TCP_INPUT_N_NEXT,
3596 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3597 foreach_tcp4_input_next
3600 .format_buffer = format_tcp_header,
3601 .format_trace = format_tcp_rx_trace,
3605 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3608 VLIB_REGISTER_NODE (tcp6_input_node) =
3610 .function = tcp6_input,
3611 .name = "tcp6-input",
3612 /* Takes a vector of packets. */
3613 .vector_size = sizeof (u32),
3614 .n_errors = TCP_N_ERROR,
3615 .error_strings = tcp_error_strings,
3616 .n_next_nodes = TCP_INPUT_N_NEXT,
3619 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3620 foreach_tcp6_input_next
3623 .format_buffer = format_tcp_header,
3624 .format_trace = format_tcp_rx_trace,
3628 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3631 tcp_dispatch_table_init (tcp_main_t * tm)
3634 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3635 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3637 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3638 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3641 #define _(t,f,n,e) \
3643 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3644 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3647 /* RFC 793: In LISTEN if RST drop and if ACK return RST */
3648 _(LISTEN, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3649 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_ACK_INVALID);
3650 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_INVALID_CONNECTION);
3651 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3652 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3653 TCP_ERROR_ACK_INVALID);
3654 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3655 TCP_ERROR_SEGMENT_INVALID);
3656 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3657 TCP_ERROR_SEGMENT_INVALID);
3658 _(LISTEN, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3659 TCP_ERROR_INVALID_CONNECTION);
3660 _(LISTEN, TCP_FLAG_FIN, TCP_INPUT_NEXT_RESET, TCP_ERROR_SEGMENT_INVALID);
3661 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3662 TCP_ERROR_SEGMENT_INVALID);
3663 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3664 TCP_ERROR_SEGMENT_INVALID);
3665 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3667 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_DROP,
3668 TCP_ERROR_SEGMENT_INVALID);
3669 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3670 TCP_ERROR_SEGMENT_INVALID);
3671 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3672 TCP_ERROR_SEGMENT_INVALID);
3673 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3674 TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3675 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3676 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3677 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3678 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3680 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3681 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3683 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3685 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3686 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3687 _(SYN_RCVD, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3688 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3690 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3692 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3693 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3694 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3696 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3697 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3698 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3699 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3700 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3701 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3702 _(SYN_RCVD, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3703 /* SYN-ACK for a SYN */
3704 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3706 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3707 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3708 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3710 _(SYN_SENT, TCP_FLAG_FIN, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3711 _(SYN_SENT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3713 /* ACK for for established connection -> tcp-established. */
3714 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3715 /* FIN for for established connection -> tcp-established. */
3716 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3717 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3719 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3721 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3722 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3723 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED,
3725 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3726 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3727 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3728 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3729 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3730 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3731 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3732 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3734 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3735 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3737 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3739 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3740 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3741 _(ESTABLISHED, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3742 /* ACK or FIN-ACK to our FIN */
3743 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3744 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3746 /* FIN in reply to our FIN from the other side */
3747 _(FIN_WAIT_1, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3748 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3749 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3751 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3752 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3753 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3754 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3755 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3756 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3757 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3759 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3760 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3761 _(FIN_WAIT_1, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3762 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3764 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3766 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3767 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3768 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3769 _(FIN_WAIT_1, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3771 _(CLOSING, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3772 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3773 _(CLOSING, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3774 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3776 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3778 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3779 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3780 _(CLOSING, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3781 _(CLOSING, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3783 _(CLOSING, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3784 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3786 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3788 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3789 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3790 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3792 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3793 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3794 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3795 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3796 /* FIN confirming that the peer (app) has closed */
3797 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3798 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3799 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3801 _(FIN_WAIT_2, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3802 _(FIN_WAIT_2, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3804 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3805 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3807 _(CLOSE_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3808 _(CLOSE_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3810 _(LAST_ACK, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3811 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3812 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3813 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3815 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3817 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3818 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3819 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3821 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3822 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3823 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3824 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3825 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3826 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3827 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3828 _(LAST_ACK, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3830 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3831 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3833 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3835 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3836 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3837 _(TIME_WAIT, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3838 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3839 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3841 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3842 _(TIME_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3844 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3845 /* RFC793 CLOSED: An incoming segment containing a RST is discarded. An
3846 * incoming segment not containing a RST causes a RST to be sent in
3848 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3849 _(CLOSED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3850 TCP_ERROR_CONNECTION_CLOSED);
3851 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3852 _(CLOSED, TCP_FLAG_SYN, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3853 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3858 static clib_error_t *
3859 tcp_input_init (vlib_main_t * vm)
3861 clib_error_t *error = 0;
3862 tcp_main_t *tm = vnet_get_tcp_main ();
3864 if ((error = vlib_call_init_function (vm, tcp_init)))
3867 /* Initialize dispatch table. */
3868 tcp_dispatch_table_init (tm);
3873 VLIB_INIT_FUNCTION (tcp_input_init);
3876 * fd.io coding-style-patch-verification: ON
3879 * eval: (c-set-style "gnu")