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 recovery, we reset snd_nxt to snd_una. Seems peer
1554 * still has the data so accept the ack */
1555 if (tcp_in_recovery (tc)
1556 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_congestion))
1558 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1559 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
1560 tc->snd_una_max = tc->snd_nxt;
1564 /* If we have outstanding data and this is within the window, accept it,
1565 * probably retransmit has timed out. Otherwise ACK segment and then
1567 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1569 tcp_program_ack (wrk, tc);
1570 *error = TCP_ERROR_ACK_FUTURE;
1571 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1572 vnet_buffer (b)->tcp.ack_number);
1576 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1577 vnet_buffer (b)->tcp.ack_number);
1579 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1582 /* If old ACK, probably it's an old dupack */
1583 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1585 *error = TCP_ERROR_ACK_OLD;
1586 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1587 vnet_buffer (b)->tcp.ack_number);
1588 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1589 tcp_cc_handle_event (tc, 1);
1590 /* Don't drop yet */
1595 * Looks okay, process feedback
1598 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1599 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1601 prev_snd_wnd = tc->snd_wnd;
1602 prev_snd_una = tc->snd_una;
1603 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1604 vnet_buffer (b)->tcp.ack_number,
1605 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1606 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1607 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1608 tcp_validate_txf_size (tc, tc->bytes_acked);
1610 if (tc->bytes_acked)
1612 tcp_program_dequeue (wrk, tc);
1613 tcp_update_rtt (tc, vnet_buffer (b)->tcp.ack_number);
1616 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1619 * Check if we have congestion event
1622 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1624 tcp_cc_handle_event (tc, is_dack);
1625 if (!tcp_in_cong_recovery (tc))
1627 *error = TCP_ERROR_ACK_OK;
1630 *error = TCP_ERROR_ACK_DUP;
1631 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1637 * Update congestion control (slow start/congestion avoidance)
1639 tcp_cc_update (tc, b);
1640 *error = TCP_ERROR_ACK_OK;
1645 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1647 if (!tcp_disconnect_pending (tc))
1649 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1650 tcp_disconnect_pending_on (tc);
1655 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1657 u32 thread_index, *pending_disconnects;
1658 tcp_connection_t *tc;
1661 if (!vec_len (wrk->pending_disconnects))
1664 thread_index = wrk->vm->thread_index;
1665 pending_disconnects = wrk->pending_disconnects;
1666 for (i = 0; i < vec_len (pending_disconnects); i++)
1668 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1669 tcp_disconnect_pending_off (tc);
1670 session_transport_closing_notify (&tc->connection);
1672 _vec_len (wrk->pending_disconnects) = 0;
1676 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1679 /* Account for the FIN and send ack */
1681 tcp_program_ack (wrk, tc);
1682 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1683 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1684 tcp_connection_set_state (tc, TCP_STATE_CLOSE_WAIT);
1685 tcp_program_disconnect (wrk, tc);
1686 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1687 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc);
1688 *error = TCP_ERROR_FIN_RCVD;
1692 tcp_sack_vector_is_sane (sack_block_t * sacks)
1695 for (i = 1; i < vec_len (sacks); i++)
1697 if (sacks[i - 1].end == sacks[i].start)
1704 * Build SACK list as per RFC2018.
1706 * Makes sure the first block contains the segment that generated the current
1707 * ACK and the following ones are the ones most recently reported in SACK
1710 * @param tc TCP connection for which the SACK list is updated
1711 * @param start Start sequence number of the newest SACK block
1712 * @param end End sequence of the newest SACK block
1715 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1717 sack_block_t *new_list = tc->snd_sacks_fl, *block = 0;
1720 /* If the first segment is ooo add it to the list. Last write might've moved
1721 * rcv_nxt over the first segment. */
1722 if (seq_lt (tc->rcv_nxt, start))
1724 vec_add2 (new_list, block, 1);
1725 block->start = start;
1729 /* Find the blocks still worth keeping. */
1730 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1732 /* Discard if rcv_nxt advanced beyond current block */
1733 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1736 /* Merge or drop if segment overlapped by the new segment */
1737 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1738 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1740 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1741 new_list[0].start = tc->snd_sacks[i].start;
1742 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1743 new_list[0].end = tc->snd_sacks[i].end;
1747 /* Save to new SACK list if we have space. */
1748 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1750 vec_add1 (new_list, tc->snd_sacks[i]);
1754 clib_warning ("sack discarded");
1758 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1760 /* Replace old vector with new one */
1761 vec_reset_length (tc->snd_sacks);
1762 tc->snd_sacks_fl = tc->snd_sacks;
1763 tc->snd_sacks = new_list;
1765 /* Segments should not 'touch' */
1766 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1770 tcp_sack_list_bytes (tcp_connection_t * tc)
1773 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1774 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1778 /** Enqueue data for delivery to application */
1780 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1783 int written, error = TCP_ERROR_ENQUEUED;
1785 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1787 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1788 1 /* queue event */ , 1);
1790 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1792 /* Update rcv_nxt */
1793 if (PREDICT_TRUE (written == data_len))
1795 tc->rcv_nxt += written;
1797 /* If more data written than expected, account for out-of-order bytes. */
1798 else if (written > data_len)
1800 tc->rcv_nxt += written;
1801 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1803 else if (written > 0)
1805 /* We've written something but FIFO is probably full now */
1806 tc->rcv_nxt += written;
1807 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1811 return TCP_ERROR_FIFO_FULL;
1814 /* Update SACK list if need be */
1815 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1817 /* Remove SACK blocks that have been delivered */
1818 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1824 /** Enqueue out-of-order data */
1826 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1832 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1835 /* Enqueue out-of-order data with relative offset */
1836 rv = session_enqueue_stream_connection (&tc->connection, b,
1837 vnet_buffer (b)->tcp.seq_number -
1838 tc->rcv_nxt, 0 /* queue event */ ,
1841 /* Nothing written */
1844 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1845 return TCP_ERROR_FIFO_FULL;
1848 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1850 /* Update SACK list if in use */
1851 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1853 ooo_segment_t *newest;
1856 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1858 /* Get the newest segment from the fifo */
1859 newest = svm_fifo_newest_ooo_segment (s0->rx_fifo);
1862 offset = ooo_segment_offset (s0->rx_fifo, newest);
1863 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1864 start = tc->rcv_nxt + offset;
1865 end = start + ooo_segment_length (s0->rx_fifo, newest);
1866 tcp_update_sack_list (tc, start, end);
1867 svm_fifo_newest_ooo_segment_reset (s0->rx_fifo);
1868 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1872 return TCP_ERROR_ENQUEUED_OOO;
1876 * Check if ACK could be delayed. If ack can be delayed, it should return
1877 * true for a full frame. If we're always acking return 0.
1880 tcp_can_delack (tcp_connection_t * tc)
1882 /* Send ack if ... */
1884 /* just sent a rcv wnd 0 */
1885 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1886 /* constrained to send ack */
1887 || (tc->flags & TCP_CONN_SNDACK) != 0
1888 /* we're almost out of tx wnd */
1889 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1896 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1898 u32 discard, first = b->current_length;
1899 vlib_main_t *vm = vlib_get_main ();
1901 /* Handle multi-buffer segments */
1902 if (n_bytes_to_drop > b->current_length)
1904 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1908 discard = clib_min (n_bytes_to_drop, b->current_length);
1909 vlib_buffer_advance (b, discard);
1910 b = vlib_get_buffer (vm, b->next_buffer);
1911 n_bytes_to_drop -= discard;
1913 while (n_bytes_to_drop);
1914 if (n_bytes_to_drop > first)
1915 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1918 vlib_buffer_advance (b, n_bytes_to_drop);
1919 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1924 * Receive buffer for connection and handle acks
1926 * It handles both in order or out-of-order data.
1929 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1932 u32 error, n_bytes_to_drop, n_data_bytes;
1934 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1935 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1936 ASSERT (n_data_bytes);
1938 /* Handle out-of-order data */
1939 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1941 /* Old sequence numbers allowed through because they overlapped
1943 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1945 /* Completely in the past (possible retransmit). Ack
1946 * retransmissions since we may not have any data to send */
1947 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1949 tcp_program_ack (wrk, tc);
1950 error = TCP_ERROR_SEGMENT_OLD;
1954 /* Chop off the bytes in the past and see if what is left
1955 * can be enqueued in order */
1956 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1957 n_data_bytes -= n_bytes_to_drop;
1958 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1959 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1961 error = TCP_ERROR_SEGMENT_OLD;
1967 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1968 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1969 tcp_program_dupack (wrk, tc);
1970 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1976 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1977 * segments can be enqueued after fifo tail offset changes. */
1978 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1979 if (tcp_can_delack (tc))
1981 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1982 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1986 tcp_program_ack (wrk, tc);
1994 tcp_header_t tcp_header;
1995 tcp_connection_t tcp_connection;
1999 format_tcp_rx_trace (u8 * s, va_list * args)
2001 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2002 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2003 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2004 u32 indent = format_get_indent (s);
2006 s = format (s, "%U\n%U%U",
2007 format_tcp_header, &t->tcp_header, 128,
2008 format_white_space, indent,
2009 format_tcp_connection, &t->tcp_connection, 1);
2015 format_tcp_rx_trace_short (u8 * s, va_list * args)
2017 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2018 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2019 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2021 s = format (s, "%d -> %d (%U)",
2022 clib_net_to_host_u16 (t->tcp_header.dst_port),
2023 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
2024 t->tcp_connection.state);
2030 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
2031 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
2035 clib_memcpy_fast (&t0->tcp_connection, tc0,
2036 sizeof (t0->tcp_connection));
2040 th0 = tcp_buffer_hdr (b0);
2042 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2046 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2047 vlib_frame_t * frame, u8 is_ip4)
2051 n_left = frame->n_vectors;
2052 from = vlib_frame_vector_args (frame);
2056 tcp_connection_t *tc0;
2063 b0 = vlib_get_buffer (vm, bi0);
2065 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2067 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2068 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2070 th0 = tcp_buffer_hdr (b0);
2071 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2080 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2081 u8 is_ip4, u32 evt, u32 val)
2084 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2086 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2089 #define tcp_maybe_inc_counter(node_id, err, count) \
2091 if (next0 != tcp_next_drop (is_ip4)) \
2092 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2093 tcp6_##node_id##_node.index, is_ip4, err, \
2096 #define tcp_inc_counter(node_id, err, count) \
2097 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2098 tcp6_##node_id##_node.index, is_ip4, \
2100 #define tcp_maybe_inc_err_counter(cnts, err) \
2102 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2104 #define tcp_inc_err_counter(cnts, err, val) \
2108 #define tcp_store_err_counters(node_id, cnts) \
2111 for (i = 0; i < TCP_N_ERROR; i++) \
2113 tcp_inc_counter(node_id, i, cnts[i]); \
2118 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2119 vlib_frame_t * frame, int is_ip4)
2121 u32 thread_index = vm->thread_index, errors = 0;
2122 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2123 u32 n_left_from, *from, *first_buffer;
2124 u16 err_counters[TCP_N_ERROR] = { 0 };
2126 if (node->flags & VLIB_NODE_FLAG_TRACE)
2127 tcp_established_trace_frame (vm, node, frame, is_ip4);
2129 first_buffer = from = vlib_frame_vector_args (frame);
2130 n_left_from = frame->n_vectors;
2132 while (n_left_from > 0)
2134 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2137 tcp_connection_t *tc0;
2139 if (n_left_from > 1)
2142 pb = vlib_get_buffer (vm, from[1]);
2143 vlib_prefetch_buffer_header (pb, LOAD);
2144 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2151 b0 = vlib_get_buffer (vm, bi0);
2152 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2155 if (PREDICT_FALSE (tc0 == 0))
2157 error0 = TCP_ERROR_INVALID_CONNECTION;
2161 th0 = tcp_buffer_hdr (b0);
2163 /* TODO header prediction fast path */
2165 /* 1-4: check SEQ, RST, SYN */
2166 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2168 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2172 /* 5: check the ACK field */
2173 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2176 /* 6: check the URG bit TODO */
2178 /* 7: process the segment text */
2179 if (vnet_buffer (b0)->tcp.data_len)
2180 error0 = tcp_segment_rcv (wrk, tc0, b0);
2182 /* 8: check the FIN bit */
2183 if (PREDICT_FALSE (tcp_is_fin (th0)))
2184 tcp_rcv_fin (wrk, tc0, b0, &error0);
2187 tcp_inc_err_counter (err_counters, error0, 1);
2190 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2192 err_counters[TCP_ERROR_MSG_QUEUE_FULL] = errors;
2193 tcp_store_err_counters (established, err_counters);
2194 tcp_handle_postponed_dequeues (wrk);
2195 tcp_handle_disconnects (wrk);
2196 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2198 return frame->n_vectors;
2202 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2203 vlib_frame_t * from_frame)
2205 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2209 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2210 vlib_frame_t * from_frame)
2212 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2216 VLIB_REGISTER_NODE (tcp4_established_node) =
2218 .function = tcp4_established,
2219 .name = "tcp4-established",
2220 /* Takes a vector of packets. */
2221 .vector_size = sizeof (u32),
2222 .n_errors = TCP_N_ERROR,
2223 .error_strings = tcp_error_strings,
2224 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2227 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2228 foreach_tcp_state_next
2231 .format_trace = format_tcp_rx_trace_short,
2235 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
2238 VLIB_REGISTER_NODE (tcp6_established_node) =
2240 .function = tcp6_established,
2241 .name = "tcp6-established",
2242 /* Takes a vector of packets. */
2243 .vector_size = sizeof (u32),
2244 .n_errors = TCP_N_ERROR,
2245 .error_strings = tcp_error_strings,
2246 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2249 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2250 foreach_tcp_state_next
2253 .format_trace = format_tcp_rx_trace_short,
2258 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
2260 vlib_node_registration_t tcp4_syn_sent_node;
2261 vlib_node_registration_t tcp6_syn_sent_node;
2264 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2266 transport_connection_t *tmp = 0;
2273 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2276 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2277 && (tc->state == TCP_STATE_LISTEN
2278 || tc->c_rmt_port == hdr->src_port));
2282 handle = session_lookup_half_open_handle (&tc->connection);
2283 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2284 tc->c_proto, tc->c_is_ip4);
2288 if (tmp->lcl_port == hdr->dst_port
2289 && tmp->rmt_port == hdr->src_port)
2291 TCP_DBG ("half-open is valid!");
2299 * Lookup transport connection
2301 static tcp_connection_t *
2302 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2306 transport_connection_t *tconn;
2307 tcp_connection_t *tc;
2312 ip4 = vlib_buffer_get_current (b);
2313 tcp = ip4_next_header (ip4);
2314 tconn = session_lookup_connection_wt4 (fib_index,
2319 TRANSPORT_PROTO_TCP,
2320 thread_index, &is_filtered);
2321 tc = tcp_get_connection_from_transport (tconn);
2322 ASSERT (tcp_lookup_is_valid (tc, tcp));
2327 ip6 = vlib_buffer_get_current (b);
2328 tcp = ip6_next_header (ip6);
2329 tconn = session_lookup_connection_wt6 (fib_index,
2334 TRANSPORT_PROTO_TCP,
2335 thread_index, &is_filtered);
2336 tc = tcp_get_connection_from_transport (tconn);
2337 ASSERT (tcp_lookup_is_valid (tc, tcp));
2343 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2344 vlib_frame_t * from_frame, int is_ip4)
2346 tcp_main_t *tm = vnet_get_tcp_main ();
2347 u32 n_left_from, *from, *first_buffer, errors = 0;
2348 u32 my_thread_index = vm->thread_index;
2349 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2351 from = first_buffer = vlib_frame_vector_args (from_frame);
2352 n_left_from = from_frame->n_vectors;
2354 while (n_left_from > 0)
2356 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2357 tcp_connection_t *tc0, *new_tc0;
2358 tcp_header_t *tcp0 = 0;
2366 b0 = vlib_get_buffer (vm, bi0);
2368 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2369 if (PREDICT_FALSE (tc0 == 0))
2371 error0 = TCP_ERROR_INVALID_CONNECTION;
2375 /* Half-open completed recently but the connection was't removed
2376 * yet by the owning thread */
2377 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2379 /* Make sure the connection actually exists */
2380 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2381 my_thread_index, is_ip4));
2382 error0 = TCP_ERROR_SPURIOUS_SYN_ACK;
2386 ack0 = vnet_buffer (b0)->tcp.ack_number;
2387 seq0 = vnet_buffer (b0)->tcp.seq_number;
2388 tcp0 = tcp_buffer_hdr (b0);
2390 /* Crude check to see if the connection handle does not match
2391 * the packet. Probably connection just switched to established */
2392 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2393 || tcp0->src_port != tc0->c_rmt_port))
2395 error0 = TCP_ERROR_INVALID_CONNECTION;
2399 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2400 && !tcp_syn (tcp0)))
2402 error0 = TCP_ERROR_SEGMENT_INVALID;
2406 /* SYNs consume sequence numbers */
2407 vnet_buffer (b0)->tcp.seq_end += tcp_is_syn (tcp0);
2410 * 1. check the ACK bit
2414 * If the ACK bit is set
2415 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2416 * the RST bit is set, if so drop the segment and return)
2417 * <SEQ=SEG.ACK><CTL=RST>
2418 * and discard the segment. Return.
2419 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2423 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2425 if (!tcp_rst (tcp0))
2426 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2427 error0 = TCP_ERROR_RCV_WND;
2431 /* Make sure ACK is valid */
2432 if (seq_gt (tc0->snd_una, ack0))
2434 error0 = TCP_ERROR_ACK_INVALID;
2440 * 2. check the RST bit
2445 /* If ACK is acceptable, signal client that peer is not
2446 * willing to accept connection and drop connection*/
2448 tcp_connection_reset (tc0);
2449 error0 = TCP_ERROR_RST_RCVD;
2454 * 3. check the security and precedence (skipped)
2458 * 4. check the SYN bit
2461 /* No SYN flag. Drop. */
2462 if (!tcp_syn (tcp0))
2464 error0 = TCP_ERROR_SEGMENT_INVALID;
2469 if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1))
2471 error0 = TCP_ERROR_OPTIONS;
2475 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2476 * current thread pool. */
2477 pool_get (tm->connections[my_thread_index], new_tc0);
2478 clib_memcpy_fast (new_tc0, tc0, sizeof (*new_tc0));
2479 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2480 new_tc0->c_thread_index = my_thread_index;
2481 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2482 new_tc0->irs = seq0;
2483 new_tc0->timers[TCP_TIMER_ESTABLISH_AO] = TCP_TIMER_HANDLE_INVALID;
2484 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2485 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2487 /* If this is not the owning thread, wait for syn retransmit to
2488 * expire and cleanup then */
2489 if (tcp_half_open_connection_cleanup (tc0))
2490 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2492 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2494 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2495 new_tc0->tsval_recent_age = tcp_time_now ();
2498 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2499 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2501 new_tc0->rcv_wscale = 0;
2503 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2504 << new_tc0->snd_wscale;
2505 new_tc0->snd_wl1 = seq0;
2506 new_tc0->snd_wl2 = ack0;
2508 tcp_connection_init_vars (new_tc0);
2510 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2511 if (PREDICT_TRUE (tcp_ack (tcp0)))
2513 /* Our SYN is ACKed: we have iss < ack = snd_una */
2515 /* TODO Dequeue acknowledged segments if we support Fast Open */
2516 new_tc0->snd_una = ack0;
2517 new_tc0->state = TCP_STATE_ESTABLISHED;
2519 /* Make sure las is initialized for the wnd computation */
2520 new_tc0->rcv_las = new_tc0->rcv_nxt;
2522 /* Notify app that we have connection. If session layer can't
2523 * allocate session send reset */
2524 if (session_stream_connect_notify (&new_tc0->connection, 0))
2526 clib_warning ("connect notify fail");
2527 tcp_send_reset_w_pkt (new_tc0, b0, my_thread_index, is_ip4);
2528 tcp_connection_cleanup (new_tc0);
2532 new_tc0->tx_fifo_size =
2533 transport_tx_fifo_size (&new_tc0->connection);
2534 /* Update rtt with the syn-ack sample */
2535 tcp_estimate_initial_rtt (new_tc0);
2536 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2537 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2539 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2542 new_tc0->state = TCP_STATE_SYN_RCVD;
2544 /* Notify app that we have connection */
2545 if (session_stream_connect_notify (&new_tc0->connection, 0))
2547 tcp_connection_cleanup (new_tc0);
2548 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2549 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2553 new_tc0->tx_fifo_size =
2554 transport_tx_fifo_size (&new_tc0->connection);
2555 new_tc0->rtt_ts = 0;
2556 tcp_init_snd_vars (new_tc0);
2557 tcp_send_synack (new_tc0);
2558 error0 = TCP_ERROR_SYNS_RCVD;
2562 /* Read data, if any */
2563 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2565 clib_warning ("rcvd data in syn-sent");
2566 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2567 if (error0 == TCP_ERROR_ACK_OK)
2568 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2572 tcp_program_ack (wrk, new_tc0);
2577 tcp_inc_counter (syn_sent, error0, 1);
2578 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2580 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2581 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2582 clib_memcpy_fast (&t0->tcp_connection, tc0,
2583 sizeof (t0->tcp_connection));
2587 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2589 tcp_inc_counter (syn_sent, TCP_ERROR_MSG_QUEUE_FULL, errors);
2590 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2592 return from_frame->n_vectors;
2596 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2597 vlib_frame_t * from_frame)
2599 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2603 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2604 vlib_frame_t * from_frame)
2606 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2610 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2612 .function = tcp4_syn_sent,
2613 .name = "tcp4-syn-sent",
2614 /* Takes a vector of packets. */
2615 .vector_size = sizeof (u32),
2616 .n_errors = TCP_N_ERROR,
2617 .error_strings = tcp_error_strings,
2618 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2621 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2622 foreach_tcp_state_next
2625 .format_trace = format_tcp_rx_trace_short,
2629 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2632 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2634 .function = tcp6_syn_sent_rcv,
2635 .name = "tcp6-syn-sent",
2636 /* Takes a vector of packets. */
2637 .vector_size = sizeof (u32),
2638 .n_errors = TCP_N_ERROR,
2639 .error_strings = tcp_error_strings,
2640 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2643 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2644 foreach_tcp_state_next
2647 .format_trace = format_tcp_rx_trace_short,
2651 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2653 vlib_node_registration_t tcp4_rcv_process_node;
2654 vlib_node_registration_t tcp6_rcv_process_node;
2657 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2658 * as per RFC793 p. 64
2661 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2662 vlib_frame_t * from_frame, int is_ip4)
2664 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2665 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2666 u32 n_left_from, *from, max_dequeue;
2668 from = first_buffer = vlib_frame_vector_args (from_frame);
2669 n_left_from = from_frame->n_vectors;
2671 while (n_left_from > 0)
2673 u32 bi0, error0 = TCP_ERROR_NONE;
2674 tcp_header_t *tcp0 = 0;
2675 tcp_connection_t *tc0;
2683 b0 = vlib_get_buffer (vm, bi0);
2684 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2686 if (PREDICT_FALSE (tc0 == 0))
2688 error0 = TCP_ERROR_INVALID_CONNECTION;
2692 tcp0 = tcp_buffer_hdr (b0);
2693 is_fin0 = tcp_is_fin (tcp0);
2697 tcp_connection_t *tmp;
2698 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2700 if (tmp->state != tc0->state)
2702 if (tc0->state != TCP_STATE_CLOSED)
2703 clib_warning ("state changed");
2709 * Special treatment for CLOSED
2711 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2713 error0 = TCP_ERROR_CONNECTION_CLOSED;
2718 * For all other states (except LISTEN)
2721 /* 1-4: check SEQ, RST, SYN */
2722 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2725 /* 5: check the ACK field */
2728 case TCP_STATE_SYN_RCVD:
2730 * If the segment acknowledgment is not acceptable, form a
2732 * <SEQ=SEG.ACK><CTL=RST>
2735 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2737 tcp_connection_reset (tc0);
2738 error0 = TCP_ERROR_ACK_INVALID;
2742 /* Make sure the ack is exactly right */
2743 if (tc0->rcv_nxt != vnet_buffer (b0)->tcp.seq_number || is_fin0)
2745 tcp_connection_reset (tc0);
2746 error0 = TCP_ERROR_SEGMENT_INVALID;
2750 /* Update rtt and rto */
2751 tcp_estimate_initial_rtt (tc0);
2753 /* Switch state to ESTABLISHED */
2754 tc0->state = TCP_STATE_ESTABLISHED;
2755 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2757 /* Initialize session variables */
2758 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2759 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2760 << tc0->rcv_opts.wscale;
2761 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2762 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2764 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2765 tcp_retransmit_timer_reset (tc0);
2766 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2767 if (session_stream_accept_notify (&tc0->connection))
2769 error0 = TCP_ERROR_MSG_QUEUE_FULL;
2770 tcp_connection_reset (tc0);
2773 error0 = TCP_ERROR_ACK_OK;
2775 case TCP_STATE_ESTABLISHED:
2776 /* We can get packets in established state here because they
2777 * were enqueued before state change */
2778 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2782 case TCP_STATE_FIN_WAIT_1:
2783 /* In addition to the processing for the ESTABLISHED state, if
2784 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2785 * continue processing in that state. */
2786 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2789 /* Still have to send the FIN */
2790 if (tc0->flags & TCP_CONN_FINPNDG)
2792 /* TX fifo finally drained */
2793 max_dequeue = session_tx_fifo_max_dequeue (&tc0->connection);
2794 if (max_dequeue <= tc0->burst_acked)
2797 /* If FIN is ACKed */
2798 else if (tc0->snd_una == tc0->snd_una_max)
2800 tcp_connection_set_state (tc0, TCP_STATE_FIN_WAIT_2);
2802 /* Stop all retransmit timers because we have nothing more
2803 * to send. Enable waitclose though because we're willing to
2804 * wait for peer's FIN but not indefinitely. */
2805 tcp_connection_timers_reset (tc0);
2806 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2808 /* Don't try to deq the FIN acked */
2809 if (tc0->burst_acked > 1)
2810 session_dequeue_drop (&tc0->connection, tc0->burst_acked - 1);
2811 tc0->burst_acked = 0;
2814 case TCP_STATE_FIN_WAIT_2:
2815 /* In addition to the processing for the ESTABLISHED state, if
2816 * the retransmission queue is empty, the user's CLOSE can be
2817 * acknowledged ("ok") but do not delete the TCB. */
2818 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2820 tc0->burst_acked = 0;
2822 case TCP_STATE_CLOSE_WAIT:
2823 /* Do the same processing as for the ESTABLISHED state. */
2824 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2827 if (tc0->flags & TCP_CONN_FINPNDG)
2829 /* TX fifo finally drained */
2830 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2833 tcp_connection_timers_reset (tc0);
2834 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2835 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2839 case TCP_STATE_CLOSING:
2840 /* In addition to the processing for the ESTABLISHED state, if
2841 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2842 * otherwise ignore the segment. */
2843 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2846 tcp_connection_timers_reset (tc0);
2847 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2848 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2852 case TCP_STATE_LAST_ACK:
2853 /* The only thing that [should] arrive in this state is an
2854 * acknowledgment of our FIN. If our FIN is now acknowledged,
2855 * delete the TCB, enter the CLOSED state, and return. */
2857 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2859 error0 = TCP_ERROR_ACK_INVALID;
2862 error0 = TCP_ERROR_ACK_OK;
2863 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2864 /* Apparently our ACK for the peer's FIN was lost */
2865 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2871 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2873 /* Don't free the connection from the data path since
2874 * we can't ensure that we have no packets already enqueued
2875 * to output. Rely instead on the waitclose timer */
2876 tcp_connection_timers_reset (tc0);
2877 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2882 case TCP_STATE_TIME_WAIT:
2883 /* The only thing that can arrive in this state is a
2884 * retransmission of the remote FIN. Acknowledge it, and restart
2885 * the 2 MSL timeout. */
2887 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2890 tcp_program_ack (wrk, tc0);
2891 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2899 /* 6: check the URG bit TODO */
2901 /* 7: process the segment text */
2904 case TCP_STATE_ESTABLISHED:
2905 case TCP_STATE_FIN_WAIT_1:
2906 case TCP_STATE_FIN_WAIT_2:
2907 if (vnet_buffer (b0)->tcp.data_len)
2908 error0 = tcp_segment_rcv (wrk, tc0, b0);
2910 case TCP_STATE_CLOSE_WAIT:
2911 case TCP_STATE_CLOSING:
2912 case TCP_STATE_LAST_ACK:
2913 case TCP_STATE_TIME_WAIT:
2914 /* This should not occur, since a FIN has been received from the
2915 * remote side. Ignore the segment text. */
2919 /* 8: check the FIN bit */
2923 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2927 case TCP_STATE_ESTABLISHED:
2928 /* Account for the FIN and send ack */
2930 tcp_program_ack (wrk, tc0);
2931 tcp_connection_set_state (tc0, TCP_STATE_CLOSE_WAIT);
2932 tcp_program_disconnect (wrk, tc0);
2933 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
2935 case TCP_STATE_SYN_RCVD:
2936 /* Send FIN-ACK, enter LAST-ACK and because the app was not
2937 * notified yet, set a cleanup timer instead of relying on
2938 * disconnect notify and the implicit close call. */
2939 tcp_connection_timers_reset (tc0);
2942 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2943 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2945 case TCP_STATE_CLOSE_WAIT:
2946 case TCP_STATE_CLOSING:
2947 case TCP_STATE_LAST_ACK:
2950 case TCP_STATE_FIN_WAIT_1:
2952 tcp_connection_set_state (tc0, TCP_STATE_CLOSING);
2953 if (tc0->flags & TCP_CONN_FINPNDG)
2955 /* Drop all outstanding tx data. */
2956 session_dequeue_drop (&tc0->connection,
2957 transport_max_tx_dequeue
2958 (&tc0->connection));
2962 tcp_program_ack (wrk, tc0);
2963 /* Wait for ACK for our FIN but not forever */
2964 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2966 case TCP_STATE_FIN_WAIT_2:
2967 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2969 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2970 tcp_connection_timers_reset (tc0);
2971 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2972 tcp_program_ack (wrk, tc0);
2974 case TCP_STATE_TIME_WAIT:
2975 /* Remain in the TIME-WAIT state. Restart the time-wait
2978 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2981 error0 = TCP_ERROR_FIN_RCVD;
2985 tcp_inc_counter (rcv_process, error0, 1);
2986 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2988 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2989 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2993 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2995 tcp_inc_counter (rcv_process, TCP_ERROR_MSG_QUEUE_FULL, errors);
2996 tcp_handle_postponed_dequeues (wrk);
2997 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2999 return from_frame->n_vectors;
3003 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
3004 vlib_frame_t * from_frame)
3006 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3010 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
3011 vlib_frame_t * from_frame)
3013 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3017 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
3019 .function = tcp4_rcv_process,
3020 .name = "tcp4-rcv-process",
3021 /* Takes a vector of packets. */
3022 .vector_size = sizeof (u32),
3023 .n_errors = TCP_N_ERROR,
3024 .error_strings = tcp_error_strings,
3025 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3028 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3029 foreach_tcp_state_next
3032 .format_trace = format_tcp_rx_trace_short,
3036 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
3039 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
3041 .function = tcp6_rcv_process,
3042 .name = "tcp6-rcv-process",
3043 /* Takes a vector of packets. */
3044 .vector_size = sizeof (u32),
3045 .n_errors = TCP_N_ERROR,
3046 .error_strings = tcp_error_strings,
3047 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3050 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3051 foreach_tcp_state_next
3054 .format_trace = format_tcp_rx_trace_short,
3058 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
3060 vlib_node_registration_t tcp4_listen_node;
3061 vlib_node_registration_t tcp6_listen_node;
3064 * LISTEN state processing as per RFC 793 p. 65
3067 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3068 vlib_frame_t * from_frame, int is_ip4)
3070 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3071 u32 my_thread_index = vm->thread_index;
3073 from = first_buffer = vlib_frame_vector_args (from_frame);
3074 n_left_from = from_frame->n_vectors;
3076 while (n_left_from > 0)
3081 tcp_header_t *th0 = 0;
3082 tcp_connection_t *lc0;
3085 tcp_connection_t *child0;
3086 u32 error0 = TCP_ERROR_NONE;
3092 b0 = vlib_get_buffer (vm, bi0);
3093 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3097 ip40 = vlib_buffer_get_current (b0);
3098 th0 = ip4_next_header (ip40);
3102 ip60 = vlib_buffer_get_current (b0);
3103 th0 = ip6_next_header (ip60);
3106 /* Create child session. For syn-flood protection use filter */
3108 /* 1. first check for an RST: handled in dispatch */
3109 /* if (tcp_rst (th0))
3113 /* 2. second check for an ACK: handled in dispatch */
3114 /* if (tcp_ack (th0))
3116 tcp_send_reset (b0, is_ip4);
3121 /* 3. check for a SYN (did that already) */
3123 /* Make sure connection wasn't just created */
3124 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3126 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3128 error0 = TCP_ERROR_CREATE_EXISTS;
3132 /* Create child session and send SYN-ACK */
3133 child0 = tcp_connection_alloc (my_thread_index);
3134 child0->c_lcl_port = th0->dst_port;
3135 child0->c_rmt_port = th0->src_port;
3136 child0->c_is_ip4 = is_ip4;
3137 child0->state = TCP_STATE_SYN_RCVD;
3138 child0->c_fib_index = lc0->c_fib_index;
3142 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3143 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3147 clib_memcpy_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3148 sizeof (ip6_address_t));
3149 clib_memcpy_fast (&child0->c_rmt_ip6, &ip60->src_address,
3150 sizeof (ip6_address_t));
3153 if (tcp_options_parse (th0, &child0->rcv_opts, 1))
3155 error0 = TCP_ERROR_OPTIONS;
3156 tcp_connection_free (child0);
3160 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3161 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3162 child0->rcv_las = child0->rcv_nxt;
3163 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3165 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3166 * segments are used to initialize PAWS. */
3167 if (tcp_opts_tstamp (&child0->rcv_opts))
3169 child0->tsval_recent = child0->rcv_opts.tsval;
3170 child0->tsval_recent_age = tcp_time_now ();
3173 if (tcp_opts_wscale (&child0->rcv_opts))
3174 child0->snd_wscale = child0->rcv_opts.wscale;
3176 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3177 << child0->snd_wscale;
3178 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3179 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3181 tcp_connection_init_vars (child0);
3182 child0->rto = TCP_RTO_MIN;
3183 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
3185 if (session_stream_accept (&child0->connection, lc0->c_s_index,
3188 tcp_connection_cleanup (child0);
3189 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3193 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3194 tcp_send_synack (child0);
3195 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
3199 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3201 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3202 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3203 clib_memcpy_fast (&t0->tcp_connection, lc0,
3204 sizeof (t0->tcp_connection));
3207 n_syns += (error0 == TCP_ERROR_NONE);
3210 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3211 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3213 return from_frame->n_vectors;
3217 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3218 vlib_frame_t * from_frame)
3220 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3224 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3225 vlib_frame_t * from_frame)
3227 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3231 VLIB_REGISTER_NODE (tcp4_listen_node) =
3233 .function = tcp4_listen,
3234 .name = "tcp4-listen",
3235 /* Takes a vector of packets. */
3236 .vector_size = sizeof (u32),
3237 .n_errors = TCP_N_ERROR,
3238 .error_strings = tcp_error_strings,
3239 .n_next_nodes = TCP_LISTEN_N_NEXT,
3242 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3243 foreach_tcp_state_next
3246 .format_trace = format_tcp_rx_trace_short,
3250 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
3253 VLIB_REGISTER_NODE (tcp6_listen_node) =
3255 .function = tcp6_listen,
3256 .name = "tcp6-listen",
3257 /* Takes a vector of packets. */
3258 .vector_size = sizeof (u32),
3259 .n_errors = TCP_N_ERROR,
3260 .error_strings = tcp_error_strings,
3261 .n_next_nodes = TCP_LISTEN_N_NEXT,
3264 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3265 foreach_tcp_state_next
3268 .format_trace = format_tcp_rx_trace_short,
3272 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
3274 vlib_node_registration_t tcp4_input_node;
3275 vlib_node_registration_t tcp6_input_node;
3277 typedef enum _tcp_input_next
3279 TCP_INPUT_NEXT_DROP,
3280 TCP_INPUT_NEXT_LISTEN,
3281 TCP_INPUT_NEXT_RCV_PROCESS,
3282 TCP_INPUT_NEXT_SYN_SENT,
3283 TCP_INPUT_NEXT_ESTABLISHED,
3284 TCP_INPUT_NEXT_RESET,
3285 TCP_INPUT_NEXT_PUNT,
3289 #define foreach_tcp4_input_next \
3290 _ (DROP, "ip4-drop") \
3291 _ (LISTEN, "tcp4-listen") \
3292 _ (RCV_PROCESS, "tcp4-rcv-process") \
3293 _ (SYN_SENT, "tcp4-syn-sent") \
3294 _ (ESTABLISHED, "tcp4-established") \
3295 _ (RESET, "tcp4-reset") \
3296 _ (PUNT, "ip4-punt")
3298 #define foreach_tcp6_input_next \
3299 _ (DROP, "ip6-drop") \
3300 _ (LISTEN, "tcp6-listen") \
3301 _ (RCV_PROCESS, "tcp6-rcv-process") \
3302 _ (SYN_SENT, "tcp6-syn-sent") \
3303 _ (ESTABLISHED, "tcp6-established") \
3304 _ (RESET, "tcp6-reset") \
3305 _ (PUNT, "ip6-punt")
3307 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3310 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3311 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3313 tcp_connection_t *tc;
3318 for (i = 0; i < n_bufs; i++)
3320 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3322 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3323 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3325 tcp = vlib_buffer_get_current (bs[i]);
3326 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3332 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3334 if (*error == TCP_ERROR_FILTERED || *error == TCP_ERROR_WRONG_THREAD)
3336 *next = TCP_INPUT_NEXT_DROP;
3338 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3340 *next = TCP_INPUT_NEXT_PUNT;
3341 *error = TCP_ERROR_PUNT;
3345 *next = TCP_INPUT_NEXT_RESET;
3346 *error = TCP_ERROR_NO_LISTENER;
3350 static inline tcp_connection_t *
3351 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3354 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3355 int n_advance_bytes, n_data_bytes;
3356 transport_connection_t *tc;
3362 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3363 int ip_hdr_bytes = ip4_header_bytes (ip4);
3364 if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
3366 *error = TCP_ERROR_LENGTH;
3369 tcp = ip4_next_header (ip4);
3370 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3371 n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
3372 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3374 /* Length check. Checksum computed by ipx_local no need to compute again */
3375 if (PREDICT_FALSE (n_data_bytes < 0))
3377 *error = TCP_ERROR_LENGTH;
3381 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3382 &ip4->src_address, tcp->dst_port,
3383 tcp->src_port, TRANSPORT_PROTO_TCP,
3384 thread_index, &result);
3388 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3389 if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
3391 *error = TCP_ERROR_LENGTH;
3394 tcp = ip6_next_header (ip6);
3395 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3396 n_advance_bytes = tcp_header_bytes (tcp);
3397 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3399 n_advance_bytes += sizeof (ip6[0]);
3401 if (PREDICT_FALSE (n_data_bytes < 0))
3403 *error = TCP_ERROR_LENGTH;
3407 (ip6_address_is_link_local_unicast (&ip6->dst_address)))
3409 ip4_main_t *im = &ip4_main;
3410 fib_index = vec_elt (im->fib_index_by_sw_if_index,
3411 vnet_buffer (b)->sw_if_index[VLIB_RX]);
3414 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3415 &ip6->src_address, tcp->dst_port,
3416 tcp->src_port, TRANSPORT_PROTO_TCP,
3417 thread_index, &result);
3420 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3421 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3422 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3423 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3424 vnet_buffer (b)->tcp.seq_end = vnet_buffer (b)->tcp.seq_number
3426 vnet_buffer (b)->tcp.flags = 0;
3428 *error = result ? TCP_ERROR_NONE + result : *error;
3430 return tcp_get_connection_from_transport (tc);
3434 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3435 vlib_buffer_t * b, u16 * next, u32 * error)
3440 tcp = tcp_buffer_hdr (b);
3441 flags = tcp->flags & filter_flags;
3442 *next = tm->dispatch_table[tc->state][flags].next;
3443 *error = tm->dispatch_table[tc->state][flags].error;
3445 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3446 || *next == TCP_INPUT_NEXT_RESET))
3448 /* Overload tcp flags to store state */
3449 tcp_state_t state = tc->state;
3450 vnet_buffer (b)->tcp.flags = tc->state;
3452 if (*error == TCP_ERROR_DISPATCH)
3453 clib_warning ("tcp conn %u disp error state %U flags %U",
3454 tc->c_c_index, format_tcp_state, state,
3455 format_tcp_flags, (int) flags);
3460 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3461 vlib_frame_t * frame, int is_ip4)
3463 u32 n_left_from, *from, thread_index = vm->thread_index;
3464 tcp_main_t *tm = vnet_get_tcp_main ();
3465 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3466 u16 nexts[VLIB_FRAME_SIZE], *next;
3468 tcp_set_time_now (tcp_get_worker (thread_index));
3470 from = vlib_frame_vector_args (frame);
3471 n_left_from = frame->n_vectors;
3472 vlib_get_buffers (vm, from, bufs, n_left_from);
3477 while (n_left_from >= 4)
3479 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3480 tcp_connection_t *tc0, *tc1;
3483 vlib_prefetch_buffer_header (b[2], STORE);
3484 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3486 vlib_prefetch_buffer_header (b[3], STORE);
3487 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3490 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3492 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3493 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4);
3495 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3497 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3498 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3500 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3501 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3503 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3504 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3508 if (PREDICT_TRUE (tc0 != 0))
3510 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3511 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3512 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3515 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3517 if (PREDICT_TRUE (tc1 != 0))
3519 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3520 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3521 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3524 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3531 while (n_left_from > 0)
3533 tcp_connection_t *tc0;
3534 u32 error0 = TCP_ERROR_NO_LISTENER;
3536 if (n_left_from > 1)
3538 vlib_prefetch_buffer_header (b[1], STORE);
3539 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3542 next[0] = TCP_INPUT_NEXT_DROP;
3543 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3544 if (PREDICT_TRUE (tc0 != 0))
3546 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3547 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3548 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3551 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3558 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3559 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3561 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3562 return frame->n_vectors;
3566 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3567 vlib_frame_t * from_frame)
3569 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3573 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3574 vlib_frame_t * from_frame)
3576 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3580 VLIB_REGISTER_NODE (tcp4_input_node) =
3582 .function = tcp4_input,
3583 .name = "tcp4-input",
3584 /* Takes a vector of packets. */
3585 .vector_size = sizeof (u32),
3586 .n_errors = TCP_N_ERROR,
3587 .error_strings = tcp_error_strings,
3588 .n_next_nodes = TCP_INPUT_N_NEXT,
3591 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3592 foreach_tcp4_input_next
3595 .format_buffer = format_tcp_header,
3596 .format_trace = format_tcp_rx_trace,
3600 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3603 VLIB_REGISTER_NODE (tcp6_input_node) =
3605 .function = tcp6_input,
3606 .name = "tcp6-input",
3607 /* Takes a vector of packets. */
3608 .vector_size = sizeof (u32),
3609 .n_errors = TCP_N_ERROR,
3610 .error_strings = tcp_error_strings,
3611 .n_next_nodes = TCP_INPUT_N_NEXT,
3614 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3615 foreach_tcp6_input_next
3618 .format_buffer = format_tcp_header,
3619 .format_trace = format_tcp_rx_trace,
3623 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3626 tcp_dispatch_table_init (tcp_main_t * tm)
3629 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3630 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3632 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3633 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3636 #define _(t,f,n,e) \
3638 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3639 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3642 /* RFC 793: In LISTEN if RST drop and if ACK return RST */
3643 _(LISTEN, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3644 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_ACK_INVALID);
3645 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_INVALID_CONNECTION);
3646 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3647 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3648 TCP_ERROR_ACK_INVALID);
3649 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3650 TCP_ERROR_SEGMENT_INVALID);
3651 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3652 TCP_ERROR_SEGMENT_INVALID);
3653 _(LISTEN, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3654 TCP_ERROR_INVALID_CONNECTION);
3655 _(LISTEN, TCP_FLAG_FIN, TCP_INPUT_NEXT_RESET, TCP_ERROR_SEGMENT_INVALID);
3656 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3657 TCP_ERROR_SEGMENT_INVALID);
3658 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3659 TCP_ERROR_SEGMENT_INVALID);
3660 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3662 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_DROP,
3663 TCP_ERROR_SEGMENT_INVALID);
3664 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3665 TCP_ERROR_SEGMENT_INVALID);
3666 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3667 TCP_ERROR_SEGMENT_INVALID);
3668 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3669 TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3670 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3671 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3672 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3673 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3675 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3676 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3678 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3680 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3681 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3682 _(SYN_RCVD, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3683 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3685 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3687 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3688 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3689 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3691 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3692 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3693 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3694 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3695 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3696 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3697 _(SYN_RCVD, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3698 /* SYN-ACK for a SYN */
3699 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3701 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3702 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3703 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3705 _(SYN_SENT, TCP_FLAG_FIN, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3706 _(SYN_SENT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3708 /* ACK for for established connection -> tcp-established. */
3709 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3710 /* FIN for for established connection -> tcp-established. */
3711 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3712 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3714 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3716 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3717 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3718 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED,
3720 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3721 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3722 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3723 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3724 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3725 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3726 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3727 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3729 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3730 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3732 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3734 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3735 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3736 _(ESTABLISHED, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3737 /* ACK or FIN-ACK to our FIN */
3738 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3739 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3741 /* FIN in reply to our FIN from the other side */
3742 _(FIN_WAIT_1, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3743 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3744 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3746 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3747 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3748 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3749 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3750 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3751 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3752 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3754 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3755 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3756 _(FIN_WAIT_1, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3757 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3759 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3761 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3762 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3763 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3764 _(FIN_WAIT_1, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3766 _(CLOSING, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3767 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3768 _(CLOSING, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3769 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3771 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3773 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3774 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3775 _(CLOSING, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3776 _(CLOSING, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3778 _(CLOSING, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3779 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3781 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3783 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3784 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3785 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3787 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3788 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3789 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3790 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3791 /* FIN confirming that the peer (app) has closed */
3792 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3793 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3794 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3796 _(FIN_WAIT_2, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3797 _(FIN_WAIT_2, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3799 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3800 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3802 _(CLOSE_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3803 _(CLOSE_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3805 _(LAST_ACK, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3806 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3807 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3808 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3810 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3812 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3813 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3814 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3816 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3817 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3818 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3819 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3820 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3821 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3822 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3823 _(LAST_ACK, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3825 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3826 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3828 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3830 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3831 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3832 _(TIME_WAIT, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3833 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3834 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3836 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3837 _(TIME_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3839 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3840 /* RFC793 CLOSED: An incoming segment containing a RST is discarded. An
3841 * incoming segment not containing a RST causes a RST to be sent in
3843 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3844 _(CLOSED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3845 TCP_ERROR_CONNECTION_CLOSED);
3846 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3847 _(CLOSED, TCP_FLAG_SYN, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3848 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3853 static clib_error_t *
3854 tcp_input_init (vlib_main_t * vm)
3856 clib_error_t *error = 0;
3857 tcp_main_t *tm = vnet_get_tcp_main ();
3859 if ((error = vlib_call_init_function (vm, tcp_init)))
3862 /* Initialize dispatch table. */
3863 tcp_dispatch_table_init (tm);
3868 VLIB_INIT_FUNCTION (tcp_input_init);
3871 * fd.io coding-style-patch-verification: ON
3874 * eval: (c-set-style "gnu")