2 * Copyright (c) 2016-2019 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
16 #include <vppinfra/sparse_vec.h>
17 #include <vnet/tcp/tcp_packet.h>
18 #include <vnet/tcp/tcp.h>
19 #include <vnet/session/session.h>
22 static char *tcp_error_strings[] = {
23 #define tcp_error(n,s) s,
24 #include <vnet/tcp/tcp_error.def>
28 /* All TCP nodes have the same outgoing arcs */
29 #define foreach_tcp_state_next \
30 _ (DROP4, "ip4-drop") \
31 _ (DROP6, "ip6-drop") \
32 _ (TCP4_OUTPUT, "tcp4-output") \
33 _ (TCP6_OUTPUT, "tcp6-output")
35 typedef enum _tcp_established_next
37 #define _(s,n) TCP_ESTABLISHED_NEXT_##s,
38 foreach_tcp_state_next
40 TCP_ESTABLISHED_N_NEXT,
41 } tcp_established_next_t;
43 typedef enum _tcp_rcv_process_next
45 #define _(s,n) TCP_RCV_PROCESS_NEXT_##s,
46 foreach_tcp_state_next
48 TCP_RCV_PROCESS_N_NEXT,
49 } tcp_rcv_process_next_t;
51 typedef enum _tcp_syn_sent_next
53 #define _(s,n) TCP_SYN_SENT_NEXT_##s,
54 foreach_tcp_state_next
57 } tcp_syn_sent_next_t;
59 typedef enum _tcp_listen_next
61 #define _(s,n) TCP_LISTEN_NEXT_##s,
62 foreach_tcp_state_next
67 /* Generic, state independent indices */
68 typedef enum _tcp_state_next
70 #define _(s,n) TCP_NEXT_##s,
71 foreach_tcp_state_next
76 #define tcp_next_output(is_ip4) (is_ip4 ? TCP_NEXT_TCP4_OUTPUT \
77 : TCP_NEXT_TCP6_OUTPUT)
79 #define tcp_next_drop(is_ip4) (is_ip4 ? TCP_NEXT_DROP4 \
83 * Validate segment sequence number. As per RFC793:
85 * Segment Receive Test
87 * ------- ------- -------------------------------------------
88 * 0 0 SEG.SEQ = RCV.NXT
89 * 0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
91 * >0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
92 * or RCV.NXT =< SEG.SEQ+SEG.LEN-1 < RCV.NXT+RCV.WND
94 * This ultimately consists in checking if segment falls within the window.
95 * The one important difference compared to RFC793 is that we use rcv_las,
96 * or the rcv_nxt at last ack sent instead of rcv_nxt since that's the
97 * peer's reference when computing our receive window.
100 * seq_leq (end_seq, tc->rcv_las + tc->rcv_wnd) && seq_geq (seq, tc->rcv_las)
101 * however, is too strict when we have retransmits. Instead we just check that
102 * the seq is not beyond the right edge and that the end of the segment is not
103 * less than the left edge.
105 * N.B. rcv_nxt and rcv_wnd are both updated in this node if acks are sent, so
106 * use rcv_nxt in the right edge window test instead of rcv_las.
110 tcp_segment_in_rcv_wnd (tcp_connection_t * tc, u32 seq, u32 end_seq)
112 return (seq_geq (end_seq, tc->rcv_las)
113 && seq_leq (seq, tc->rcv_nxt + tc->rcv_wnd));
117 * Parse TCP header options.
119 * @param th TCP header
120 * @param to TCP options data structure to be populated
121 * @param is_syn set if packet is syn
122 * @return -1 if parsing failed
125 tcp_options_parse (tcp_header_t * th, tcp_options_t * to, u8 is_syn)
128 u8 opt_len, opts_len, kind;
132 opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t);
133 data = (const u8 *) (th + 1);
135 /* Zero out all flags but those set in SYN */
136 to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE
137 | TCP_OPTS_FLAG_TSTAMP | TCP_OPTION_MSS);
139 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
143 /* Get options length */
144 if (kind == TCP_OPTION_EOL)
146 else if (kind == TCP_OPTION_NOOP)
158 /* weird option length */
159 if (opt_len < 2 || opt_len > opts_len)
169 if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
171 to->flags |= TCP_OPTS_FLAG_MSS;
172 to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
175 case TCP_OPTION_WINDOW_SCALE:
178 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
180 to->flags |= TCP_OPTS_FLAG_WSCALE;
181 to->wscale = data[2];
182 if (to->wscale > TCP_MAX_WND_SCALE)
183 to->wscale = TCP_MAX_WND_SCALE;
186 case TCP_OPTION_TIMESTAMP:
188 to->flags |= TCP_OPTS_FLAG_TSTAMP;
189 if ((to->flags & TCP_OPTS_FLAG_TSTAMP)
190 && opt_len == TCP_OPTION_LEN_TIMESTAMP)
192 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
193 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
196 case TCP_OPTION_SACK_PERMITTED:
199 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
200 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
202 case TCP_OPTION_SACK_BLOCK:
203 /* If SACK permitted was not advertised or a SYN, break */
204 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
207 /* If too short or not correctly formatted, break */
208 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
211 to->flags |= TCP_OPTS_FLAG_SACK;
212 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
213 vec_reset_length (to->sacks);
214 for (j = 0; j < to->n_sack_blocks; j++)
216 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 8 * j));
217 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 8 * j));
218 vec_add1 (to->sacks, b);
222 /* Nothing to see here */
230 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
231 * timestamp to echo and it's less than tsval_recent, drop segment
232 * but still send an ACK in order to retain TCP's mechanism for detecting
233 * and recovering from half-open connections
235 * Or at least that's what the theory says. It seems that this might not work
236 * very well with packet reordering and fast retransmit. XXX
239 tcp_segment_check_paws (tcp_connection_t * tc)
241 return tcp_opts_tstamp (&tc->rcv_opts)
242 && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent);
246 * Update tsval recent
249 tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
252 * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
253 * of an incoming segment:
254 * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
255 * then the TSval from the segment is copied to TS.Recent;
256 * otherwise, the TSval is ignored.
258 if (tcp_opts_tstamp (&tc->rcv_opts) && seq_leq (seq, tc->rcv_las)
259 && seq_leq (tc->rcv_las, seq_end))
261 ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval));
262 tc->tsval_recent = tc->rcv_opts.tsval;
263 tc->tsval_recent_age = tcp_time_now_w_thread (tc->c_thread_index);
268 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
270 * It first verifies if segment has a wrapped sequence number (PAWS) and then
271 * does the processing associated to the first four steps (ignoring security
272 * and precedence): sequence number, rst bit and syn bit checks.
274 * @return 0 if segments passes validation.
277 tcp_segment_validate (tcp_worker_ctx_t * wrk, tcp_connection_t * tc0,
278 vlib_buffer_t * b0, tcp_header_t * th0, u32 * error0)
280 /* We could get a burst of RSTs interleaved with acks */
281 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
283 tcp_send_reset (tc0);
284 *error0 = TCP_ERROR_CONNECTION_CLOSED;
288 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
290 *error0 = TCP_ERROR_SEGMENT_INVALID;
294 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts, 0)))
296 *error0 = TCP_ERROR_OPTIONS;
300 if (PREDICT_FALSE (tcp_segment_check_paws (tc0)))
302 *error0 = TCP_ERROR_PAWS;
303 TCP_EVT_DBG (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
304 vnet_buffer (b0)->tcp.seq_end);
306 /* If it just so happens that a segment updates tsval_recent for a
307 * segment over 24 days old, invalidate tsval_recent. */
308 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
309 tcp_time_now_w_thread (tc0->c_thread_index)))
311 tc0->tsval_recent = tc0->rcv_opts.tsval;
312 clib_warning ("paws failed: 24-day old segment");
314 /* Drop after ack if not rst. Resets can fail paws check as per
315 * RFC 7323 sec. 5.2: When an <RST> segment is received, it MUST NOT
316 * be subjected to the PAWS check by verifying an acceptable value in
318 else if (!tcp_rst (th0))
320 tcp_program_ack (wrk, tc0);
321 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
326 /* 1st: check sequence number */
327 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
328 vnet_buffer (b0)->tcp.seq_end))
330 /* SYN/SYN-ACK retransmit */
332 && vnet_buffer (b0)->tcp.seq_number == tc0->rcv_nxt - 1)
334 tcp_options_parse (th0, &tc0->rcv_opts, 1);
335 if (tc0->state == TCP_STATE_SYN_RCVD)
337 tcp_send_synack (tc0);
338 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0, 0);
339 *error0 = TCP_ERROR_SYNS_RCVD;
343 tcp_program_ack (wrk, tc0);
344 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, tc0);
345 *error0 = TCP_ERROR_SYN_ACKS_RCVD;
350 /* If our window is 0 and the packet is in sequence, let it pass
351 * through for ack processing. It should be dropped later. */
352 if (tc0->rcv_wnd < tc0->snd_mss
353 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number)
356 /* If we entered recovery and peer did so as well, there's a chance that
357 * dup acks won't be acceptable on either end because seq_end may be less
358 * than rcv_las. This can happen if acks are lost in both directions. */
359 if (tcp_in_recovery (tc0)
360 && seq_geq (vnet_buffer (b0)->tcp.seq_number,
361 tc0->rcv_las - tc0->rcv_wnd)
362 && seq_leq (vnet_buffer (b0)->tcp.seq_end,
363 tc0->rcv_nxt + tc0->rcv_wnd))
366 *error0 = TCP_ERROR_RCV_WND;
368 /* If not RST, send dup ack */
371 tcp_program_dupack (wrk, tc0);
372 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
380 /* 2nd: check the RST bit */
381 if (PREDICT_FALSE (tcp_rst (th0)))
383 tcp_connection_reset (tc0);
384 *error0 = TCP_ERROR_RST_RCVD;
388 /* 3rd: check security and precedence (skip) */
390 /* 4th: check the SYN bit (in window) */
391 if (PREDICT_FALSE (tcp_syn (th0)))
393 /* As per RFC5961 send challenge ack instead of reset */
394 tcp_program_ack (wrk, tc0);
395 *error0 = TCP_ERROR_SPURIOUS_SYN;
399 /* If segment in window, save timestamp */
400 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
401 vnet_buffer (b0)->tcp.seq_end);
409 tcp_rcv_ack_no_cc (tcp_connection_t * tc, vlib_buffer_t * b, u32 * error)
411 /* SND.UNA =< SEG.ACK =< SND.NXT */
412 if (!(seq_leq (tc->snd_una, vnet_buffer (b)->tcp.ack_number)
413 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
415 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)
416 && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
418 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
421 *error = TCP_ERROR_ACK_INVALID;
426 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
427 tc->snd_una = vnet_buffer (b)->tcp.ack_number;
428 *error = TCP_ERROR_ACK_OK;
433 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
435 * Note that although the original article, srtt and rttvar are scaled
436 * to minimize round-off errors, here we don't. Instead, we rely on
437 * better precision time measurements.
439 * TODO support us rtt resolution
442 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
448 err = mrtt - tc->srtt;
450 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
451 * The increase should be bound */
452 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
453 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
454 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
458 /* First measurement. */
460 tc->rttvar = mrtt >> 1;
464 #ifndef CLIB_MARCH_VARIANT
466 tcp_update_rto (tcp_connection_t * tc)
468 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
469 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
471 #endif /* CLIB_MARCH_VARIANT */
474 * Update RTT estimate and RTO timer
476 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
477 * timing. Middle boxes are known to fiddle with TCP options so we
478 * should give higher priority to ACK timing.
480 * This should be called only if previously sent bytes have been acked.
482 * return 1 if valid rtt 0 otherwise
485 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
489 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
490 * RTT because they're ambiguous. */
491 if (tcp_in_cong_recovery (tc) || tc->sack_sb.sacked_bytes)
493 if (tcp_in_recovery (tc))
498 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
500 f64 sample = tcp_time_now_us (tc->c_thread_index) - tc->rtt_ts;
501 tc->mrtt_us = tc->mrtt_us + (sample - tc->mrtt_us) * 0.125;
502 mrtt = clib_max ((u32) (sample * THZ), 1);
503 /* Allow measuring of a new RTT */
506 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
507 * snd_una, i.e., the left side of the send window:
508 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
509 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
511 u32 now = tcp_tstamp (tc);
512 mrtt = clib_max (now - tc->rcv_opts.tsecr, 1);
515 /* Ignore dubious measurements */
516 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
519 tcp_estimate_rtt (tc, mrtt);
523 /* If we got here something must've been ACKed so make sure boff is 0,
524 * even if mrtt is not valid since we update the rto lower */
532 tcp_estimate_initial_rtt (tcp_connection_t * tc)
534 u8 thread_index = vlib_num_workers ()? 1 : 0;
539 tc->mrtt_us = tcp_time_now_us (thread_index) - tc->rtt_ts;
540 tc->mrtt_us = clib_max (tc->mrtt_us, 0.0001);
541 mrtt = clib_max ((u32) (tc->mrtt_us * THZ), 1);
546 mrtt = tcp_time_now_w_thread (thread_index) - tc->rcv_opts.tsecr;
547 mrtt = clib_max (mrtt, 1);
548 /* Due to retransmits we don't know the initial mrtt */
549 if (tc->rto_boff && mrtt > 1 * THZ)
551 tc->mrtt_us = (f64) mrtt *TCP_TICK;
554 if (mrtt > 0 && mrtt < TCP_RTT_MAX)
555 tcp_estimate_rtt (tc, mrtt);
560 * Dequeue bytes for connections that have received acks in last burst
563 tcp_handle_postponed_dequeues (tcp_worker_ctx_t * wrk)
565 u32 thread_index = wrk->vm->thread_index;
566 u32 *pending_deq_acked;
567 tcp_connection_t *tc;
570 if (!vec_len (wrk->pending_deq_acked))
573 pending_deq_acked = wrk->pending_deq_acked;
574 for (i = 0; i < vec_len (pending_deq_acked); i++)
576 tc = tcp_connection_get (pending_deq_acked[i], thread_index);
577 tc->flags &= ~TCP_CONN_DEQ_PENDING;
579 if (PREDICT_FALSE (!tc->burst_acked))
582 /* Dequeue the newly ACKed bytes */
583 session_tx_fifo_dequeue_drop (&tc->connection, tc->burst_acked);
585 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
587 if (PREDICT_FALSE (tc->flags & TCP_CONN_PSH_PENDING))
589 if (seq_leq (tc->psh_seq, tc->snd_una))
590 tc->flags &= ~TCP_CONN_PSH_PENDING;
593 /* If everything has been acked, stop retransmit timer
594 * otherwise update. */
595 tcp_retransmit_timer_update (tc);
597 /* If not congested, update pacer based on our new
599 if (!tcp_in_fastrecovery (tc))
600 tcp_connection_tx_pacer_update (tc);
602 _vec_len (wrk->pending_deq_acked) = 0;
606 tcp_program_dequeue (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
608 if (!(tc->flags & TCP_CONN_DEQ_PENDING))
610 vec_add1 (wrk->pending_deq_acked, tc->c_c_index);
611 tc->flags |= TCP_CONN_DEQ_PENDING;
613 tc->burst_acked += tc->bytes_acked + tc->sack_sb.snd_una_adv;
617 * Check if duplicate ack as per RFC5681 Sec. 2
620 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
623 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
624 && seq_gt (tc->snd_nxt, tc->snd_una)
625 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
626 && (prev_snd_wnd == tc->snd_wnd));
630 * Checks if ack is a congestion control event.
633 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
634 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
636 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
637 * defined to be 'duplicate' */
638 *is_dack = tc->sack_sb.last_sacked_bytes
639 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
641 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
644 #ifndef CLIB_MARCH_VARIANT
646 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
648 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
649 return hole - sb->holes;
653 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
655 return hole->end - hole->start;
658 sack_scoreboard_hole_t *
659 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
661 if (index != TCP_INVALID_SACK_HOLE_INDEX)
662 return pool_elt_at_index (sb->holes, index);
666 sack_scoreboard_hole_t *
667 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
669 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
670 return pool_elt_at_index (sb->holes, hole->next);
674 sack_scoreboard_hole_t *
675 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
677 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
678 return pool_elt_at_index (sb->holes, hole->prev);
682 sack_scoreboard_hole_t *
683 scoreboard_first_hole (sack_scoreboard_t * sb)
685 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
686 return pool_elt_at_index (sb->holes, sb->head);
690 sack_scoreboard_hole_t *
691 scoreboard_last_hole (sack_scoreboard_t * sb)
693 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
694 return pool_elt_at_index (sb->holes, sb->tail);
699 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
701 sack_scoreboard_hole_t *next, *prev;
703 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
705 next = pool_elt_at_index (sb->holes, hole->next);
706 next->prev = hole->prev;
710 sb->tail = hole->prev;
713 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
715 prev = pool_elt_at_index (sb->holes, hole->prev);
716 prev->next = hole->next;
720 sb->head = hole->next;
723 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
724 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
726 /* Poison the entry */
728 clib_memset (hole, 0xfe, sizeof (*hole));
730 pool_put (sb->holes, hole);
733 static sack_scoreboard_hole_t *
734 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
737 sack_scoreboard_hole_t *hole, *next, *prev;
740 pool_get (sb->holes, hole);
741 clib_memset (hole, 0, sizeof (*hole));
745 hole_index = scoreboard_hole_index (sb, hole);
747 prev = scoreboard_get_hole (sb, prev_index);
750 hole->prev = prev_index;
751 hole->next = prev->next;
753 if ((next = scoreboard_next_hole (sb, hole)))
754 next->prev = hole_index;
756 sb->tail = hole_index;
758 prev->next = hole_index;
762 sb->head = hole_index;
763 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
764 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
769 #endif /* CLIB_MARCH_VARIANT */
771 #ifndef CLIB_MARCH_VARIANT
773 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
775 sack_scoreboard_hole_t *left, *right;
776 u32 bytes = 0, blks = 0;
779 sb->sacked_bytes = 0;
780 left = scoreboard_last_hole (sb);
784 if (seq_gt (sb->high_sacked, left->end))
786 bytes = sb->high_sacked - left->end;
790 while ((right = left)
791 && bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
792 && blks < TCP_DUPACK_THRESHOLD
793 /* left not updated if above conditions fail */
794 && (left = scoreboard_prev_hole (sb, right)))
796 bytes += right->start - left->end;
800 /* left is first lost */
805 sb->lost_bytes += scoreboard_hole_bytes (right);
807 left = scoreboard_prev_hole (sb, right);
809 bytes += right->start - left->end;
811 while ((right = left));
814 sb->sacked_bytes = bytes;
818 * Figure out the next hole to retransmit
820 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
822 sack_scoreboard_hole_t *
823 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
824 sack_scoreboard_hole_t * start,
825 u8 have_unsent, u8 * can_rescue, u8 * snd_limited)
827 sack_scoreboard_hole_t *hole = 0;
829 hole = start ? start : scoreboard_first_hole (sb);
830 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
831 hole = scoreboard_next_hole (sb, hole);
833 /* Nothing, return */
836 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
840 /* Rule (1): if higher than rxt, less than high_sacked and lost */
841 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
843 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
847 /* Rule (2): available unsent data */
850 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
853 /* Rule (3): if hole not lost */
854 else if (seq_lt (hole->start, sb->high_sacked))
857 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
859 /* Rule (4): if hole beyond high_sacked */
862 ASSERT (seq_geq (hole->start, sb->high_sacked));
865 /* HighRxt MUST NOT be updated */
870 if (hole && seq_lt (sb->high_rxt, hole->start))
871 sb->high_rxt = hole->start;
875 #endif /* CLIB_MARCH_VARIANT */
878 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 snd_una)
880 sack_scoreboard_hole_t *hole;
881 hole = scoreboard_first_hole (sb);
884 snd_una = seq_gt (snd_una, hole->start) ? snd_una : hole->start;
885 sb->cur_rxt_hole = sb->head;
887 sb->high_rxt = snd_una;
888 sb->rescue_rxt = snd_una - 1;
891 #ifndef CLIB_MARCH_VARIANT
893 scoreboard_init (sack_scoreboard_t * sb)
895 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
896 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
897 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
901 scoreboard_clear (sack_scoreboard_t * sb)
903 sack_scoreboard_hole_t *hole;
904 while ((hole = scoreboard_first_hole (sb)))
906 scoreboard_remove_hole (sb, hole);
908 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
909 ASSERT (pool_elts (sb->holes) == 0);
910 sb->sacked_bytes = 0;
911 sb->last_sacked_bytes = 0;
912 sb->last_bytes_delivered = 0;
917 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
919 #endif /* CLIB_MARCH_VARIANT */
922 * Test that scoreboard is sane after recovery
924 * Returns 1 if scoreboard is empty or if first hole beyond
928 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
930 sack_scoreboard_hole_t *hole;
931 hole = scoreboard_first_hole (&tc->sack_sb);
932 return (!hole || (seq_geq (hole->start, tc->snd_una)
933 && seq_lt (hole->end, tc->snd_nxt)));
936 #ifndef CLIB_MARCH_VARIANT
938 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
940 sack_scoreboard_t *sb = &tc->sack_sb;
941 sack_block_t *blk, tmp;
942 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
943 u32 blk_index = 0, old_sacked_bytes, hole_index;
946 sb->last_sacked_bytes = 0;
947 sb->last_bytes_delivered = 0;
950 if (!tcp_opts_sack (&tc->rcv_opts)
951 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
954 old_sacked_bytes = sb->sacked_bytes;
956 /* Remove invalid blocks */
957 blk = tc->rcv_opts.sacks;
958 while (blk < vec_end (tc->rcv_opts.sacks))
960 if (seq_lt (blk->start, blk->end)
961 && seq_gt (blk->start, tc->snd_una)
962 && seq_gt (blk->start, ack)
963 && seq_lt (blk->start, tc->snd_nxt)
964 && seq_leq (blk->end, tc->snd_nxt))
969 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
972 /* Add block for cumulative ack */
973 if (seq_gt (ack, tc->snd_una))
975 tmp.start = tc->snd_una;
977 vec_add1 (tc->rcv_opts.sacks, tmp);
980 if (vec_len (tc->rcv_opts.sacks) == 0)
983 tcp_scoreboard_trace_add (tc, ack);
985 /* Make sure blocks are ordered */
986 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
987 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
988 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
990 tmp = tc->rcv_opts.sacks[i];
991 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
992 tc->rcv_opts.sacks[j] = tmp;
995 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
997 /* If no holes, insert the first that covers all outstanding bytes */
998 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
999 tc->snd_una, tc->snd_nxt);
1000 sb->tail = scoreboard_hole_index (sb, last_hole);
1001 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
1002 sb->high_sacked = tmp.end;
1006 /* If we have holes but snd_una_max is beyond the last hole, update
1008 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
1009 last_hole = scoreboard_last_hole (sb);
1010 if (seq_gt (tc->snd_nxt, last_hole->end))
1012 if (seq_geq (last_hole->start, sb->high_sacked))
1014 last_hole->end = tc->snd_nxt;
1016 /* New hole after high sacked block */
1017 else if (seq_lt (sb->high_sacked, tc->snd_nxt))
1019 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
1023 /* Keep track of max byte sacked for when the last hole
1025 if (seq_gt (tmp.end, sb->high_sacked))
1026 sb->high_sacked = tmp.end;
1029 /* Walk the holes with the SACK blocks */
1030 hole = pool_elt_at_index (sb->holes, sb->head);
1031 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
1033 blk = &tc->rcv_opts.sacks[blk_index];
1034 if (seq_leq (blk->start, hole->start))
1036 /* Block covers hole. Remove hole */
1037 if (seq_geq (blk->end, hole->end))
1039 next_hole = scoreboard_next_hole (sb, hole);
1041 /* Byte accounting: snd_una needs to be advanced */
1042 if (blk->end == ack)
1046 if (seq_lt (ack, next_hole->start))
1047 sb->snd_una_adv = next_hole->start - ack;
1048 sb->last_bytes_delivered +=
1049 next_hole->start - hole->end;
1053 ASSERT (seq_geq (sb->high_sacked, ack));
1054 sb->snd_una_adv = sb->high_sacked - ack;
1055 sb->last_bytes_delivered += sb->high_sacked - hole->end;
1059 scoreboard_remove_hole (sb, hole);
1062 /* Partial 'head' overlap */
1065 if (seq_gt (blk->end, hole->start))
1067 hole->start = blk->end;
1074 /* Hole must be split */
1075 if (seq_lt (blk->end, hole->end))
1077 hole_index = scoreboard_hole_index (sb, hole);
1078 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
1081 /* Pool might've moved */
1082 hole = scoreboard_get_hole (sb, hole_index);
1083 hole->end = blk->start;
1085 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
1087 else if (seq_lt (blk->start, hole->end))
1089 hole->end = blk->start;
1091 hole = scoreboard_next_hole (sb, hole);
1095 if (pool_elts (sb->holes) == 1)
1097 hole = scoreboard_first_hole (sb);
1098 if (hole->start == ack + sb->snd_una_adv && hole->end == tc->snd_nxt)
1099 scoreboard_remove_hole (sb, hole);
1102 scoreboard_update_bytes (tc, sb);
1103 sb->last_sacked_bytes = sb->sacked_bytes
1104 - (old_sacked_bytes - sb->last_bytes_delivered);
1105 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
1106 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
1107 || sb->sacked_bytes < tc->snd_nxt - seq_max (tc->snd_una, ack));
1108 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_nxt
1109 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1110 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1111 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
1112 TCP_EVT_DBG (TCP_EVT_CC_SCOREBOARD, tc);
1114 #endif /* CLIB_MARCH_VARIANT */
1117 * Try to update snd_wnd based on feedback received from peer.
1119 * If successful, and new window is 'effectively' 0, activate persist
1123 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1125 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1126 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1127 if (seq_lt (tc->snd_wl1, seq)
1128 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1130 tc->snd_wnd = snd_wnd;
1133 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
1135 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
1137 /* Set persist timer if not set and we just got 0 wnd */
1138 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1139 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1140 tcp_persist_timer_set (tc);
1144 tcp_persist_timer_reset (tc);
1145 if (PREDICT_FALSE (!tcp_in_recovery (tc) && tc->rto_boff > 0))
1148 tcp_update_rto (tc);
1154 #ifndef CLIB_MARCH_VARIANT
1156 * Init loss recovery/fast recovery.
1158 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1159 * updated in @ref tcp_cc_handle_event after fast retransmit
1162 tcp_cc_init_congestion (tcp_connection_t * tc)
1164 tcp_fastrecovery_on (tc);
1165 tc->snd_congestion = tc->snd_nxt;
1166 tc->cwnd_acc_bytes = 0;
1167 tc->snd_rxt_bytes = 0;
1168 tc->prev_ssthresh = tc->ssthresh;
1169 tc->prev_cwnd = tc->cwnd;
1170 tc->cc_algo->congestion (tc);
1171 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
1173 #endif /* CLIB_MARCH_VARIANT */
1176 tcp_cc_recovery_exit (tcp_connection_t * tc)
1179 tcp_update_rto (tc);
1182 tcp_recovery_off (tc);
1183 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1186 #ifndef CLIB_MARCH_VARIANT
1188 tcp_cc_fastrecovery_clear (tcp_connection_t * tc)
1190 tc->snd_rxt_bytes = 0;
1191 tc->rcv_dupacks = 0;
1194 tcp_fastrecovery_off (tc);
1195 tcp_fastrecovery_first_off (tc);
1197 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1199 #endif /* CLIB_MARCH_VARIANT */
1202 tcp_cc_congestion_undo (tcp_connection_t * tc)
1204 tc->cwnd = tc->prev_cwnd;
1205 tc->ssthresh = tc->prev_ssthresh;
1206 tc->rcv_dupacks = 0;
1207 if (tcp_in_recovery (tc))
1209 tcp_cc_recovery_exit (tc);
1210 tc->snd_nxt = seq_max (tc->snd_nxt, tc->snd_congestion);
1212 else if (tcp_in_fastrecovery (tc))
1214 tcp_cc_fastrecovery_clear (tc);
1216 tcp_cc_undo_recovery (tc);
1217 ASSERT (tc->rto_boff == 0);
1218 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
1222 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1224 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1226 && tcp_opts_tstamp (&tc->rcv_opts)
1227 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1231 tcp_cc_is_spurious_fast_rxt (tcp_connection_t * tc)
1233 return (tcp_in_fastrecovery (tc)
1234 && tc->cwnd > tc->ssthresh + 3 * tc->snd_mss);
1238 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1240 return (tcp_cc_is_spurious_timeout_rxt (tc)
1241 || tcp_cc_is_spurious_fast_rxt (tc));
1245 tcp_cc_recover (tcp_connection_t * tc)
1247 ASSERT (tcp_in_cong_recovery (tc));
1248 if (tcp_cc_is_spurious_retransmit (tc))
1250 tcp_cc_congestion_undo (tc);
1254 if (tcp_in_recovery (tc))
1255 tcp_cc_recovery_exit (tc);
1256 else if (tcp_in_fastrecovery (tc))
1258 tcp_cc_recovered (tc);
1259 tcp_cc_fastrecovery_clear (tc);
1262 ASSERT (tc->rto_boff == 0);
1263 ASSERT (!tcp_in_cong_recovery (tc));
1264 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1269 tcp_cc_update (tcp_connection_t * tc, tcp_rate_sample_t * rs)
1271 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1273 /* Congestion avoidance */
1274 tcp_cc_rcv_ack (tc, rs);
1276 /* If a cumulative ack, make sure dupacks is 0 */
1277 tc->rcv_dupacks = 0;
1279 /* When dupacks hits the threshold we only enter fast retransmit if
1280 * cumulative ack covers more than snd_congestion. Should snd_una
1281 * wrap this test may fail under otherwise valid circumstances.
1282 * Therefore, proactively update snd_congestion when wrap detected. */
1284 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1285 && seq_gt (tc->snd_congestion, tc->snd_una)))
1286 tc->snd_congestion = tc->snd_una - 1;
1290 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1292 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1296 tcp_should_fastrecover (tcp_connection_t * tc)
1298 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1299 || tcp_should_fastrecover_sack (tc));
1302 #ifndef CLIB_MARCH_VARIANT
1304 tcp_program_fastretransmit (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1306 if (!(tc->flags & TCP_CONN_FRXT_PENDING))
1308 vec_add1 (wrk->pending_fast_rxt, tc->c_c_index);
1309 tc->flags |= TCP_CONN_FRXT_PENDING;
1314 tcp_do_fastretransmits (tcp_worker_ctx_t * wrk)
1316 u32 *ongoing_fast_rxt, burst_bytes, sent_bytes, thread_index;
1317 u32 max_burst_size, burst_size, n_segs = 0, n_segs_now;
1318 tcp_connection_t *tc;
1322 if (vec_len (wrk->pending_fast_rxt) == 0
1323 && vec_len (wrk->postponed_fast_rxt) == 0)
1326 thread_index = wrk->vm->thread_index;
1327 last_cpu_time = wrk->vm->clib_time.last_cpu_time;
1328 ongoing_fast_rxt = wrk->ongoing_fast_rxt;
1329 vec_append (ongoing_fast_rxt, wrk->postponed_fast_rxt);
1330 vec_append (ongoing_fast_rxt, wrk->pending_fast_rxt);
1332 _vec_len (wrk->postponed_fast_rxt) = 0;
1333 _vec_len (wrk->pending_fast_rxt) = 0;
1335 max_burst_size = VLIB_FRAME_SIZE / vec_len (ongoing_fast_rxt);
1336 max_burst_size = clib_max (max_burst_size, 1);
1338 for (i = 0; i < vec_len (ongoing_fast_rxt); i++)
1340 tc = tcp_connection_get (ongoing_fast_rxt[i], thread_index);
1343 if (!tcp_in_fastrecovery (tc))
1345 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1349 if (n_segs >= VLIB_FRAME_SIZE)
1351 vec_add1 (wrk->postponed_fast_rxt, ongoing_fast_rxt[i]);
1355 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1356 burst_size = clib_min (max_burst_size, VLIB_FRAME_SIZE - n_segs);
1357 burst_bytes = transport_connection_tx_pacer_burst (&tc->connection,
1359 burst_size = clib_min (burst_size, burst_bytes / tc->snd_mss);
1362 tcp_program_fastretransmit (wrk, tc);
1366 n_segs_now = tcp_fast_retransmit (wrk, tc, burst_size);
1367 sent_bytes = clib_min (n_segs_now * tc->snd_mss, burst_bytes);
1368 transport_connection_tx_pacer_update_bytes (&tc->connection,
1370 n_segs += n_segs_now;
1372 _vec_len (ongoing_fast_rxt) = 0;
1373 wrk->ongoing_fast_rxt = ongoing_fast_rxt;
1375 #endif /* CLIB_MARCH_VARIANT */
1378 * One function to rule them all ... and in the darkness bind them
1381 tcp_cc_handle_event (tcp_connection_t * tc, tcp_rate_sample_t * rs,
1386 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1388 if (tc->bytes_acked)
1390 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1394 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1395 * it account for the bytes that left the network.
1397 else if (is_dack && !tcp_in_recovery (tc))
1399 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1400 ASSERT (tc->snd_una != tc->snd_nxt || tc->sack_sb.last_sacked_bytes);
1404 /* Pure duplicate ack. If some data got acked, it's handled lower */
1405 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1407 ASSERT (tcp_in_fastrecovery (tc));
1408 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1411 else if (tcp_should_fastrecover (tc))
1415 ASSERT (!tcp_in_fastrecovery (tc));
1417 /* Heuristic to catch potential late dupacks
1418 * after fast retransmit exits */
1419 if (is_dack && tc->snd_una == tc->snd_congestion
1420 && timestamp_leq (tc->rcv_opts.tsecr, tc->tsecr_last_ack))
1422 tc->rcv_dupacks = 0;
1426 tcp_cc_init_congestion (tc);
1427 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1429 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1431 tc->cwnd = tc->ssthresh;
1432 scoreboard_init_high_rxt (&tc->sack_sb, tc->snd_una);
1436 /* Post retransmit update cwnd to ssthresh and account for the
1437 * three segments that have left the network and should've been
1438 * buffered at the receiver XXX */
1439 tc->cwnd = tc->ssthresh + 3 * tc->snd_mss;
1442 /* Constrain rate until we get a partial ack */
1443 pacer_wnd = clib_max (0.1 * tc->cwnd, 2 * tc->snd_mss);
1444 tcp_connection_tx_pacer_reset (tc, pacer_wnd,
1445 0 /* start bucket */ );
1446 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index),
1450 else if (!tc->bytes_acked
1451 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1453 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1459 /* Don't allow entry in fast recovery if still in recovery, for now */
1460 else if (0 && is_dack && tcp_in_recovery (tc))
1462 /* If of of the two conditions lower hold, reset dupacks because
1463 * we're probably after timeout (RFC6582 heuristics).
1464 * If Cumulative ack does not cover more than congestion threshold,
1466 * 1) The following doesn't hold: The congestion window is greater
1467 * than SMSS bytes and the difference between highest_ack
1468 * and prev_highest_ack is at most 4*SMSS bytes
1469 * 2) Echoed timestamp in the last non-dup ack does not equal the
1472 if (seq_leq (tc->snd_una, tc->snd_congestion)
1473 && ((!(tc->cwnd > tc->snd_mss
1474 && tc->bytes_acked <= 4 * tc->snd_mss))
1475 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1477 tc->rcv_dupacks = 0;
1482 if (!tc->bytes_acked)
1486 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1489 * Legitimate ACK. 1) See if we can exit recovery
1492 /* Update the pacing rate. For the first partial ack we move from
1493 * the artificially constrained rate to the one after congestion */
1494 tcp_connection_tx_pacer_update (tc);
1496 if (seq_geq (tc->snd_una, tc->snd_congestion))
1498 tcp_retransmit_timer_update (tc);
1500 /* If spurious return, we've already updated everything */
1501 if (tcp_cc_recover (tc))
1503 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1507 /* Treat as congestion avoidance ack */
1508 tcp_cc_rcv_ack (tc, rs);
1513 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1516 /* XXX limit this only to first partial ack? */
1517 tcp_retransmit_timer_update (tc);
1519 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1520 * reset dupacks to 0. Also needed if in congestion recovery */
1521 tc->rcv_dupacks = 0;
1523 /* Post RTO timeout don't try anything fancy */
1524 if (tcp_in_recovery (tc))
1526 tcp_cc_rcv_ack (tc, rs);
1527 transport_add_tx_event (&tc->connection);
1531 /* Remove retransmitted bytes that have been delivered */
1532 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1534 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1535 >= tc->sack_sb.last_bytes_delivered
1536 || (tc->flags & TCP_CONN_FINSNT));
1538 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1539 * remove sacked bytes delivered */
1540 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1542 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1543 - tc->sack_sb.last_bytes_delivered;
1544 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1545 tc->snd_rxt_bytes -= rxt_delivered;
1549 /* Apparently all retransmitted holes have been acked */
1550 tc->snd_rxt_bytes = 0;
1551 tc->sack_sb.high_rxt = tc->snd_una;
1556 tcp_fastrecovery_first_on (tc);
1557 if (tc->snd_rxt_bytes > tc->bytes_acked)
1558 tc->snd_rxt_bytes -= tc->bytes_acked;
1560 tc->snd_rxt_bytes = 0;
1563 tcp_cc_rcv_cong_ack (tc, TCP_CC_PARTIALACK, rs);
1566 * Since this was a partial ack, try to retransmit some more data
1568 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1572 * Process incoming ACK
1575 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1576 tcp_header_t * th, u32 * error)
1578 u32 prev_snd_wnd, prev_snd_una;
1579 tcp_rate_sample_t rs = { 0 };
1582 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1584 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1585 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1587 /* We've probably entered recovery and the peer still has some
1588 * of the data we've sent. Update snd_nxt and accept the ack */
1589 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)
1590 && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
1592 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1596 *error = TCP_ERROR_ACK_FUTURE;
1597 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1598 vnet_buffer (b)->tcp.ack_number);
1602 /* If old ACK, probably it's an old dupack */
1603 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1605 *error = TCP_ERROR_ACK_OLD;
1606 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1607 vnet_buffer (b)->tcp.ack_number);
1608 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1609 tcp_cc_handle_event (tc, 0, 1);
1610 /* Don't drop yet */
1617 * Looks okay, process feedback
1619 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1620 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1622 prev_snd_wnd = tc->snd_wnd;
1623 prev_snd_una = tc->snd_una;
1624 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1625 vnet_buffer (b)->tcp.ack_number,
1626 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1627 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1628 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1629 tcp_validate_txf_size (tc, tc->bytes_acked);
1631 if (tc->bytes_acked)
1633 tcp_program_dequeue (wrk, tc);
1634 tcp_update_rtt (tc, vnet_buffer (b)->tcp.ack_number);
1637 if (tc->flags & TCP_CONN_RATE_SAMPLE)
1638 tcp_bt_sample_delivery_rate (tc, &rs);
1640 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1643 * Check if we have congestion event
1646 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1648 tcp_cc_handle_event (tc, &rs, is_dack);
1649 if (!tcp_in_cong_recovery (tc))
1651 *error = TCP_ERROR_ACK_OK;
1654 *error = TCP_ERROR_ACK_DUP;
1655 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1661 * Update congestion control (slow start/congestion avoidance)
1663 tcp_cc_update (tc, &rs);
1664 *error = TCP_ERROR_ACK_OK;
1669 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1671 if (!tcp_disconnect_pending (tc))
1673 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1674 tcp_disconnect_pending_on (tc);
1679 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1681 u32 thread_index, *pending_disconnects;
1682 tcp_connection_t *tc;
1685 if (!vec_len (wrk->pending_disconnects))
1688 thread_index = wrk->vm->thread_index;
1689 pending_disconnects = wrk->pending_disconnects;
1690 for (i = 0; i < vec_len (pending_disconnects); i++)
1692 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1693 tcp_disconnect_pending_off (tc);
1694 session_transport_closing_notify (&tc->connection);
1696 _vec_len (wrk->pending_disconnects) = 0;
1700 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1703 /* Reject out-of-order fins */
1704 if (vnet_buffer (b)->tcp.seq_end != tc->rcv_nxt)
1707 /* Account for the FIN and send ack */
1709 tcp_program_ack (wrk, tc);
1710 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1711 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1712 tcp_connection_set_state (tc, TCP_STATE_CLOSE_WAIT);
1713 tcp_program_disconnect (wrk, tc);
1714 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1715 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc);
1716 *error = TCP_ERROR_FIN_RCVD;
1719 #ifndef CLIB_MARCH_VARIANT
1721 tcp_sack_vector_is_sane (sack_block_t * sacks)
1724 for (i = 1; i < vec_len (sacks); i++)
1726 if (sacks[i - 1].end == sacks[i].start)
1733 * Build SACK list as per RFC2018.
1735 * Makes sure the first block contains the segment that generated the current
1736 * ACK and the following ones are the ones most recently reported in SACK
1739 * @param tc TCP connection for which the SACK list is updated
1740 * @param start Start sequence number of the newest SACK block
1741 * @param end End sequence of the newest SACK block
1744 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1746 sack_block_t *new_list = tc->snd_sacks_fl, *block = 0;
1749 /* If the first segment is ooo add it to the list. Last write might've moved
1750 * rcv_nxt over the first segment. */
1751 if (seq_lt (tc->rcv_nxt, start))
1753 vec_add2 (new_list, block, 1);
1754 block->start = start;
1758 /* Find the blocks still worth keeping. */
1759 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1761 /* Discard if rcv_nxt advanced beyond current block */
1762 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1765 /* Merge or drop if segment overlapped by the new segment */
1766 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1767 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1769 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1770 new_list[0].start = tc->snd_sacks[i].start;
1771 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1772 new_list[0].end = tc->snd_sacks[i].end;
1776 /* Save to new SACK list if we have space. */
1777 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1778 vec_add1 (new_list, tc->snd_sacks[i]);
1781 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1783 /* Replace old vector with new one */
1784 vec_reset_length (tc->snd_sacks);
1785 tc->snd_sacks_fl = tc->snd_sacks;
1786 tc->snd_sacks = new_list;
1788 /* Segments should not 'touch' */
1789 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1793 tcp_sack_list_bytes (tcp_connection_t * tc)
1796 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1797 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1800 #endif /* CLIB_MARCH_VARIANT */
1802 /** Enqueue data for delivery to application */
1804 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1807 int written, error = TCP_ERROR_ENQUEUED;
1809 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1811 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1812 1 /* queue event */ , 1);
1814 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1816 /* Update rcv_nxt */
1817 if (PREDICT_TRUE (written == data_len))
1819 tc->rcv_nxt += written;
1821 /* If more data written than expected, account for out-of-order bytes. */
1822 else if (written > data_len)
1824 tc->rcv_nxt += written;
1825 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1827 else if (written > 0)
1829 /* We've written something but FIFO is probably full now */
1830 tc->rcv_nxt += written;
1831 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1835 return TCP_ERROR_FIFO_FULL;
1838 /* Update SACK list if need be */
1839 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1841 /* Remove SACK blocks that have been delivered */
1842 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1848 /** Enqueue out-of-order data */
1850 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1856 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1859 /* Enqueue out-of-order data with relative offset */
1860 rv = session_enqueue_stream_connection (&tc->connection, b,
1861 vnet_buffer (b)->tcp.seq_number -
1862 tc->rcv_nxt, 0 /* queue event */ ,
1865 /* Nothing written */
1868 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1869 return TCP_ERROR_FIFO_FULL;
1872 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1874 /* Update SACK list if in use */
1875 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1877 ooo_segment_t *newest;
1880 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1882 /* Get the newest segment from the fifo */
1883 newest = svm_fifo_newest_ooo_segment (s0->rx_fifo);
1886 offset = ooo_segment_offset_prod (s0->rx_fifo, newest);
1887 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1888 start = tc->rcv_nxt + offset;
1889 end = start + ooo_segment_length (s0->rx_fifo, newest);
1890 tcp_update_sack_list (tc, start, end);
1891 svm_fifo_newest_ooo_segment_reset (s0->rx_fifo);
1892 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1896 return TCP_ERROR_ENQUEUED_OOO;
1900 * Check if ACK could be delayed. If ack can be delayed, it should return
1901 * true for a full frame. If we're always acking return 0.
1904 tcp_can_delack (tcp_connection_t * tc)
1906 /* Send ack if ... */
1908 /* just sent a rcv wnd 0
1909 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0 */
1910 /* constrained to send ack */
1911 || (tc->flags & TCP_CONN_SNDACK) != 0
1912 /* we're almost out of tx wnd */
1913 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1920 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1922 u32 discard, first = b->current_length;
1923 vlib_main_t *vm = vlib_get_main ();
1925 /* Handle multi-buffer segments */
1926 if (n_bytes_to_drop > b->current_length)
1928 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1932 discard = clib_min (n_bytes_to_drop, b->current_length);
1933 vlib_buffer_advance (b, discard);
1934 b = vlib_get_buffer (vm, b->next_buffer);
1935 n_bytes_to_drop -= discard;
1937 while (n_bytes_to_drop);
1938 if (n_bytes_to_drop > first)
1939 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1942 vlib_buffer_advance (b, n_bytes_to_drop);
1943 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1948 * Receive buffer for connection and handle acks
1950 * It handles both in order or out-of-order data.
1953 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1956 u32 error, n_bytes_to_drop, n_data_bytes;
1958 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1959 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1960 ASSERT (n_data_bytes);
1962 /* Handle out-of-order data */
1963 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1965 /* Old sequence numbers allowed through because they overlapped
1967 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1969 /* Completely in the past (possible retransmit). Ack
1970 * retransmissions since we may not have any data to send */
1971 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1973 tcp_program_ack (wrk, tc);
1974 error = TCP_ERROR_SEGMENT_OLD;
1978 /* Chop off the bytes in the past and see if what is left
1979 * can be enqueued in order */
1980 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1981 n_data_bytes -= n_bytes_to_drop;
1982 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1983 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1985 error = TCP_ERROR_SEGMENT_OLD;
1991 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1992 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1993 tcp_program_dupack (wrk, tc);
1994 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
2000 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
2001 * segments can be enqueued after fifo tail offset changes. */
2002 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
2003 if (tcp_can_delack (tc))
2005 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
2006 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
2010 tcp_program_ack (wrk, tc);
2018 tcp_header_t tcp_header;
2019 tcp_connection_t tcp_connection;
2023 format_tcp_rx_trace (u8 * s, va_list * args)
2025 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2026 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2027 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2028 u32 indent = format_get_indent (s);
2030 s = format (s, "%U\n%U%U",
2031 format_tcp_header, &t->tcp_header, 128,
2032 format_white_space, indent,
2033 format_tcp_connection, &t->tcp_connection, 1);
2039 format_tcp_rx_trace_short (u8 * s, va_list * args)
2041 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2042 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2043 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2045 s = format (s, "%d -> %d (%U)",
2046 clib_net_to_host_u16 (t->tcp_header.dst_port),
2047 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
2048 t->tcp_connection.state);
2054 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
2055 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
2059 clib_memcpy_fast (&t0->tcp_connection, tc0,
2060 sizeof (t0->tcp_connection));
2064 th0 = tcp_buffer_hdr (b0);
2066 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2070 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2071 vlib_frame_t * frame, u8 is_ip4)
2075 n_left = frame->n_vectors;
2076 from = vlib_frame_vector_args (frame);
2080 tcp_connection_t *tc0;
2087 b0 = vlib_get_buffer (vm, bi0);
2089 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2091 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2092 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2094 th0 = tcp_buffer_hdr (b0);
2095 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2104 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2105 u8 is_ip4, u32 evt, u32 val)
2108 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2110 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2113 #define tcp_maybe_inc_counter(node_id, err, count) \
2115 if (next0 != tcp_next_drop (is_ip4)) \
2116 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2117 tcp6_##node_id##_node.index, is_ip4, err, \
2120 #define tcp_inc_counter(node_id, err, count) \
2121 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2122 tcp6_##node_id##_node.index, is_ip4, \
2124 #define tcp_maybe_inc_err_counter(cnts, err) \
2126 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2128 #define tcp_inc_err_counter(cnts, err, val) \
2132 #define tcp_store_err_counters(node_id, cnts) \
2135 for (i = 0; i < TCP_N_ERROR; i++) \
2137 tcp_inc_counter(node_id, i, cnts[i]); \
2142 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2143 vlib_frame_t * frame, int is_ip4)
2145 u32 thread_index = vm->thread_index, errors = 0;
2146 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2147 u32 n_left_from, *from, *first_buffer;
2148 u16 err_counters[TCP_N_ERROR] = { 0 };
2150 if (node->flags & VLIB_NODE_FLAG_TRACE)
2151 tcp_established_trace_frame (vm, node, frame, is_ip4);
2153 first_buffer = from = vlib_frame_vector_args (frame);
2154 n_left_from = frame->n_vectors;
2156 while (n_left_from > 0)
2158 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2161 tcp_connection_t *tc0;
2163 if (n_left_from > 1)
2166 pb = vlib_get_buffer (vm, from[1]);
2167 vlib_prefetch_buffer_header (pb, LOAD);
2168 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2175 b0 = vlib_get_buffer (vm, bi0);
2176 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2179 if (PREDICT_FALSE (tc0 == 0))
2181 error0 = TCP_ERROR_INVALID_CONNECTION;
2185 th0 = tcp_buffer_hdr (b0);
2187 /* TODO header prediction fast path */
2189 /* 1-4: check SEQ, RST, SYN */
2190 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2192 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2196 /* 5: check the ACK field */
2197 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2200 /* 6: check the URG bit TODO */
2202 /* 7: process the segment text */
2203 if (vnet_buffer (b0)->tcp.data_len)
2204 error0 = tcp_segment_rcv (wrk, tc0, b0);
2206 /* 8: check the FIN bit */
2207 if (PREDICT_FALSE (tcp_is_fin (th0)))
2208 tcp_rcv_fin (wrk, tc0, b0, &error0);
2211 tcp_inc_err_counter (err_counters, error0, 1);
2214 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2216 err_counters[TCP_ERROR_MSG_QUEUE_FULL] = errors;
2217 tcp_store_err_counters (established, err_counters);
2218 tcp_handle_postponed_dequeues (wrk);
2219 tcp_handle_disconnects (wrk);
2220 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2222 return frame->n_vectors;
2225 VLIB_NODE_FN (tcp4_established_node) (vlib_main_t * vm,
2226 vlib_node_runtime_t * node,
2227 vlib_frame_t * from_frame)
2229 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2232 VLIB_NODE_FN (tcp6_established_node) (vlib_main_t * vm,
2233 vlib_node_runtime_t * node,
2234 vlib_frame_t * from_frame)
2236 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2240 VLIB_REGISTER_NODE (tcp4_established_node) =
2242 .name = "tcp4-established",
2243 /* Takes a vector of packets. */
2244 .vector_size = sizeof (u32),
2245 .n_errors = TCP_N_ERROR,
2246 .error_strings = tcp_error_strings,
2247 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2250 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2251 foreach_tcp_state_next
2254 .format_trace = format_tcp_rx_trace_short,
2259 VLIB_REGISTER_NODE (tcp6_established_node) =
2261 .name = "tcp6-established",
2262 /* Takes a vector of packets. */
2263 .vector_size = sizeof (u32),
2264 .n_errors = TCP_N_ERROR,
2265 .error_strings = tcp_error_strings,
2266 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2269 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2270 foreach_tcp_state_next
2273 .format_trace = format_tcp_rx_trace_short,
2279 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2281 transport_connection_t *tmp = 0;
2288 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2291 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2292 && (tc->state == TCP_STATE_LISTEN
2293 || tc->c_rmt_port == hdr->src_port));
2297 handle = session_lookup_half_open_handle (&tc->connection);
2298 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2299 tc->c_proto, tc->c_is_ip4);
2303 if (tmp->lcl_port == hdr->dst_port
2304 && tmp->rmt_port == hdr->src_port)
2306 TCP_DBG ("half-open is valid!");
2314 * Lookup transport connection
2316 static tcp_connection_t *
2317 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2321 transport_connection_t *tconn;
2322 tcp_connection_t *tc;
2327 ip4 = vlib_buffer_get_current (b);
2328 tcp = ip4_next_header (ip4);
2329 tconn = session_lookup_connection_wt4 (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));
2342 ip6 = vlib_buffer_get_current (b);
2343 tcp = ip6_next_header (ip6);
2344 tconn = session_lookup_connection_wt6 (fib_index,
2349 TRANSPORT_PROTO_TCP,
2350 thread_index, &is_filtered);
2351 tc = tcp_get_connection_from_transport (tconn);
2352 ASSERT (tcp_lookup_is_valid (tc, tcp));
2358 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2359 vlib_frame_t * from_frame, int is_ip4)
2361 tcp_main_t *tm = vnet_get_tcp_main ();
2362 u32 n_left_from, *from, *first_buffer, errors = 0;
2363 u32 my_thread_index = vm->thread_index;
2364 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2366 from = first_buffer = vlib_frame_vector_args (from_frame);
2367 n_left_from = from_frame->n_vectors;
2369 while (n_left_from > 0)
2371 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2372 tcp_connection_t *tc0, *new_tc0;
2373 tcp_header_t *tcp0 = 0;
2381 b0 = vlib_get_buffer (vm, bi0);
2383 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2384 if (PREDICT_FALSE (tc0 == 0))
2386 error0 = TCP_ERROR_INVALID_CONNECTION;
2390 /* Half-open completed recently but the connection was't removed
2391 * yet by the owning thread */
2392 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2394 /* Make sure the connection actually exists */
2395 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2396 my_thread_index, is_ip4));
2397 error0 = TCP_ERROR_SPURIOUS_SYN_ACK;
2401 ack0 = vnet_buffer (b0)->tcp.ack_number;
2402 seq0 = vnet_buffer (b0)->tcp.seq_number;
2403 tcp0 = tcp_buffer_hdr (b0);
2405 /* Crude check to see if the connection handle does not match
2406 * the packet. Probably connection just switched to established */
2407 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2408 || tcp0->src_port != tc0->c_rmt_port))
2410 error0 = TCP_ERROR_INVALID_CONNECTION;
2414 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2415 && !tcp_syn (tcp0)))
2417 error0 = TCP_ERROR_SEGMENT_INVALID;
2421 /* SYNs consume sequence numbers */
2422 vnet_buffer (b0)->tcp.seq_end += tcp_is_syn (tcp0);
2425 * 1. check the ACK bit
2429 * If the ACK bit is set
2430 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2431 * the RST bit is set, if so drop the segment and return)
2432 * <SEQ=SEG.ACK><CTL=RST>
2433 * and discard the segment. Return.
2434 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2438 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2440 if (!tcp_rst (tcp0))
2441 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2442 error0 = TCP_ERROR_RCV_WND;
2446 /* Make sure ACK is valid */
2447 if (seq_gt (tc0->snd_una, ack0))
2449 error0 = TCP_ERROR_ACK_INVALID;
2455 * 2. check the RST bit
2460 /* If ACK is acceptable, signal client that peer is not
2461 * willing to accept connection and drop connection*/
2463 tcp_connection_reset (tc0);
2464 error0 = TCP_ERROR_RST_RCVD;
2469 * 3. check the security and precedence (skipped)
2473 * 4. check the SYN bit
2476 /* No SYN flag. Drop. */
2477 if (!tcp_syn (tcp0))
2479 error0 = TCP_ERROR_SEGMENT_INVALID;
2484 if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1))
2486 error0 = TCP_ERROR_OPTIONS;
2490 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2491 * current thread pool. */
2492 pool_get (tm->connections[my_thread_index], new_tc0);
2493 clib_memcpy_fast (new_tc0, tc0, sizeof (*new_tc0));
2494 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2495 new_tc0->c_thread_index = my_thread_index;
2496 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2497 new_tc0->irs = seq0;
2498 new_tc0->timers[TCP_TIMER_ESTABLISH_AO] = TCP_TIMER_HANDLE_INVALID;
2499 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2500 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2502 /* If this is not the owning thread, wait for syn retransmit to
2503 * expire and cleanup then */
2504 if (tcp_half_open_connection_cleanup (tc0))
2505 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2507 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2509 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2510 new_tc0->tsval_recent_age = tcp_time_now ();
2513 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2514 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2516 new_tc0->rcv_wscale = 0;
2518 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2519 << new_tc0->snd_wscale;
2520 new_tc0->snd_wl1 = seq0;
2521 new_tc0->snd_wl2 = ack0;
2523 tcp_connection_init_vars (new_tc0);
2525 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2526 if (PREDICT_TRUE (tcp_ack (tcp0)))
2528 /* Our SYN is ACKed: we have iss < ack = snd_una */
2530 /* TODO Dequeue acknowledged segments if we support Fast Open */
2531 new_tc0->snd_una = ack0;
2532 new_tc0->state = TCP_STATE_ESTABLISHED;
2534 /* Make sure las is initialized for the wnd computation */
2535 new_tc0->rcv_las = new_tc0->rcv_nxt;
2537 /* Notify app that we have connection. If session layer can't
2538 * allocate session send reset */
2539 if (session_stream_connect_notify (&new_tc0->connection, 0))
2541 tcp_send_reset_w_pkt (new_tc0, b0, my_thread_index, is_ip4);
2542 tcp_connection_cleanup (new_tc0);
2543 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2547 new_tc0->tx_fifo_size =
2548 transport_tx_fifo_size (&new_tc0->connection);
2549 /* Update rtt with the syn-ack sample */
2550 tcp_estimate_initial_rtt (new_tc0);
2551 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2552 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2554 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2557 new_tc0->state = TCP_STATE_SYN_RCVD;
2559 /* Notify app that we have connection */
2560 if (session_stream_connect_notify (&new_tc0->connection, 0))
2562 tcp_connection_cleanup (new_tc0);
2563 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2564 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2565 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2569 new_tc0->tx_fifo_size =
2570 transport_tx_fifo_size (&new_tc0->connection);
2571 new_tc0->rtt_ts = 0;
2572 tcp_init_snd_vars (new_tc0);
2573 tcp_send_synack (new_tc0);
2574 error0 = TCP_ERROR_SYNS_RCVD;
2578 /* Read data, if any */
2579 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2581 clib_warning ("rcvd data in syn-sent");
2582 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2583 if (error0 == TCP_ERROR_ACK_OK)
2584 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2588 tcp_program_ack (wrk, new_tc0);
2593 tcp_inc_counter (syn_sent, error0, 1);
2594 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2596 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2597 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2598 clib_memcpy_fast (&t0->tcp_connection, tc0,
2599 sizeof (t0->tcp_connection));
2603 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2605 tcp_inc_counter (syn_sent, TCP_ERROR_MSG_QUEUE_FULL, errors);
2606 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2608 return from_frame->n_vectors;
2611 VLIB_NODE_FN (tcp4_syn_sent_node) (vlib_main_t * vm,
2612 vlib_node_runtime_t * node,
2613 vlib_frame_t * from_frame)
2615 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2618 VLIB_NODE_FN (tcp6_syn_sent_node) (vlib_main_t * vm,
2619 vlib_node_runtime_t * node,
2620 vlib_frame_t * from_frame)
2622 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2626 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2628 .name = "tcp4-syn-sent",
2629 /* Takes a vector of packets. */
2630 .vector_size = sizeof (u32),
2631 .n_errors = TCP_N_ERROR,
2632 .error_strings = tcp_error_strings,
2633 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2636 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2637 foreach_tcp_state_next
2640 .format_trace = format_tcp_rx_trace_short,
2645 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2647 .name = "tcp6-syn-sent",
2648 /* Takes a vector of packets. */
2649 .vector_size = sizeof (u32),
2650 .n_errors = TCP_N_ERROR,
2651 .error_strings = tcp_error_strings,
2652 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2655 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2656 foreach_tcp_state_next
2659 .format_trace = format_tcp_rx_trace_short,
2664 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2665 * as per RFC793 p. 64
2668 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2669 vlib_frame_t * from_frame, int is_ip4)
2671 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2672 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2673 u32 n_left_from, *from, max_dequeue;
2675 from = first_buffer = vlib_frame_vector_args (from_frame);
2676 n_left_from = from_frame->n_vectors;
2678 while (n_left_from > 0)
2680 u32 bi0, error0 = TCP_ERROR_NONE;
2681 tcp_header_t *tcp0 = 0;
2682 tcp_connection_t *tc0;
2690 b0 = vlib_get_buffer (vm, bi0);
2691 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2693 if (PREDICT_FALSE (tc0 == 0))
2695 error0 = TCP_ERROR_INVALID_CONNECTION;
2699 tcp0 = tcp_buffer_hdr (b0);
2700 is_fin0 = tcp_is_fin (tcp0);
2704 tcp_connection_t *tmp;
2705 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2707 if (tmp->state != tc0->state)
2709 if (tc0->state != TCP_STATE_CLOSED)
2710 clib_warning ("state changed");
2716 * Special treatment for CLOSED
2718 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2720 error0 = TCP_ERROR_CONNECTION_CLOSED;
2725 * For all other states (except LISTEN)
2728 /* 1-4: check SEQ, RST, SYN */
2729 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2732 /* 5: check the ACK field */
2735 case TCP_STATE_SYN_RCVD:
2737 /* Make sure the segment is exactly right */
2738 if (tc0->rcv_nxt != vnet_buffer (b0)->tcp.seq_number || is_fin0)
2740 tcp_connection_reset (tc0);
2741 error0 = TCP_ERROR_SEGMENT_INVALID;
2746 * If the segment acknowledgment is not acceptable, form a
2748 * <SEQ=SEG.ACK><CTL=RST>
2751 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2753 tcp_connection_reset (tc0);
2757 /* Update rtt and rto */
2758 tcp_estimate_initial_rtt (tc0);
2760 /* Switch state to ESTABLISHED */
2761 tc0->state = TCP_STATE_ESTABLISHED;
2762 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2764 /* Initialize session variables */
2765 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2766 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2767 << tc0->rcv_opts.wscale;
2768 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2769 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2771 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2772 tcp_retransmit_timer_reset (tc0);
2773 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2774 if (session_stream_accept_notify (&tc0->connection))
2776 error0 = TCP_ERROR_MSG_QUEUE_FULL;
2777 tcp_connection_reset (tc0);
2780 error0 = TCP_ERROR_ACK_OK;
2782 case TCP_STATE_ESTABLISHED:
2783 /* We can get packets in established state here because they
2784 * were enqueued before state change */
2785 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2789 case TCP_STATE_FIN_WAIT_1:
2790 /* In addition to the processing for the ESTABLISHED state, if
2791 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2792 * continue processing in that state. */
2793 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2796 /* Still have to send the FIN */
2797 if (tc0->flags & TCP_CONN_FINPNDG)
2799 /* TX fifo finally drained */
2800 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2801 if (max_dequeue <= tc0->burst_acked)
2803 /* If a fin was received and data was acked extend wait */
2804 else if ((tc0->flags & TCP_CONN_FINRCVD) && tc0->bytes_acked)
2805 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2806 TCP_CLOSEWAIT_TIME);
2808 /* If FIN is ACKed */
2809 else if (tc0->snd_una == tc0->snd_nxt)
2811 /* Stop all retransmit timers because we have nothing more
2813 tcp_connection_timers_reset (tc0);
2815 /* We already have a FIN but didn't transition to CLOSING
2816 * because of outstanding tx data. Close the connection. */
2817 if (tc0->flags & TCP_CONN_FINRCVD)
2819 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2820 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2824 tcp_connection_set_state (tc0, TCP_STATE_FIN_WAIT_2);
2825 /* Enable waitclose because we're willing to wait for peer's
2826 * FIN but not indefinitely. */
2827 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2829 /* Don't try to deq the FIN acked */
2830 if (tc0->burst_acked > 1)
2831 session_tx_fifo_dequeue_drop (&tc0->connection,
2832 tc0->burst_acked - 1);
2833 tc0->burst_acked = 0;
2836 case TCP_STATE_FIN_WAIT_2:
2837 /* In addition to the processing for the ESTABLISHED state, if
2838 * the retransmission queue is empty, the user's CLOSE can be
2839 * acknowledged ("ok") but do not delete the TCB. */
2840 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2842 tc0->burst_acked = 0;
2844 case TCP_STATE_CLOSE_WAIT:
2845 /* Do the same processing as for the ESTABLISHED state. */
2846 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2849 if (!(tc0->flags & TCP_CONN_FINPNDG))
2852 /* Still have outstanding tx data */
2853 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2854 if (max_dequeue > tc0->burst_acked)
2858 tcp_connection_timers_reset (tc0);
2859 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2860 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2862 case TCP_STATE_CLOSING:
2863 /* In addition to the processing for the ESTABLISHED state, if
2864 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2865 * otherwise ignore the segment. */
2866 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2869 if (tc0->snd_una != tc0->snd_nxt)
2872 tcp_connection_timers_reset (tc0);
2873 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2874 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2878 case TCP_STATE_LAST_ACK:
2879 /* The only thing that [should] arrive in this state is an
2880 * acknowledgment of our FIN. If our FIN is now acknowledged,
2881 * delete the TCB, enter the CLOSED state, and return. */
2883 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2886 /* Apparently our ACK for the peer's FIN was lost */
2887 if (is_fin0 && tc0->snd_una != tc0->snd_nxt)
2893 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2895 /* Don't free the connection from the data path since
2896 * we can't ensure that we have no packets already enqueued
2897 * to output. Rely instead on the waitclose timer */
2898 tcp_connection_timers_reset (tc0);
2899 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2904 case TCP_STATE_TIME_WAIT:
2905 /* The only thing that can arrive in this state is a
2906 * retransmission of the remote FIN. Acknowledge it, and restart
2907 * the 2 MSL timeout. */
2909 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2915 tcp_program_ack (wrk, tc0);
2916 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2924 /* 6: check the URG bit TODO */
2926 /* 7: process the segment text */
2929 case TCP_STATE_ESTABLISHED:
2930 case TCP_STATE_FIN_WAIT_1:
2931 case TCP_STATE_FIN_WAIT_2:
2932 if (vnet_buffer (b0)->tcp.data_len)
2933 error0 = tcp_segment_rcv (wrk, tc0, b0);
2935 case TCP_STATE_CLOSE_WAIT:
2936 case TCP_STATE_CLOSING:
2937 case TCP_STATE_LAST_ACK:
2938 case TCP_STATE_TIME_WAIT:
2939 /* This should not occur, since a FIN has been received from the
2940 * remote side. Ignore the segment text. */
2944 /* 8: check the FIN bit */
2948 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2952 case TCP_STATE_ESTABLISHED:
2953 /* Account for the FIN and send ack */
2955 tcp_program_ack (wrk, tc0);
2956 tcp_connection_set_state (tc0, TCP_STATE_CLOSE_WAIT);
2957 tcp_program_disconnect (wrk, tc0);
2958 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
2960 case TCP_STATE_SYN_RCVD:
2961 /* Send FIN-ACK, enter LAST-ACK and because the app was not
2962 * notified yet, set a cleanup timer instead of relying on
2963 * disconnect notify and the implicit close call. */
2964 tcp_connection_timers_reset (tc0);
2967 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2968 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2970 case TCP_STATE_CLOSE_WAIT:
2971 case TCP_STATE_CLOSING:
2972 case TCP_STATE_LAST_ACK:
2975 case TCP_STATE_FIN_WAIT_1:
2978 if (tc0->flags & TCP_CONN_FINPNDG)
2980 /* If data is outstanding, stay in FIN_WAIT_1 and try to finish
2981 * sending it. Since we already received a fin, do not wait
2983 tc0->flags |= TCP_CONN_FINRCVD;
2984 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
2988 tcp_connection_set_state (tc0, TCP_STATE_CLOSING);
2989 tcp_program_ack (wrk, tc0);
2990 /* Wait for ACK for our FIN but not forever */
2991 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2994 case TCP_STATE_FIN_WAIT_2:
2995 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2997 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2998 tcp_connection_timers_reset (tc0);
2999 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
3000 tcp_program_ack (wrk, tc0);
3002 case TCP_STATE_TIME_WAIT:
3003 /* Remain in the TIME-WAIT state. Restart the time-wait
3006 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
3009 error0 = TCP_ERROR_FIN_RCVD;
3013 tcp_inc_counter (rcv_process, error0, 1);
3014 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3016 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3017 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
3021 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
3023 tcp_inc_counter (rcv_process, TCP_ERROR_MSG_QUEUE_FULL, errors);
3024 tcp_handle_postponed_dequeues (wrk);
3025 tcp_handle_disconnects (wrk);
3026 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3028 return from_frame->n_vectors;
3031 VLIB_NODE_FN (tcp4_rcv_process_node) (vlib_main_t * vm,
3032 vlib_node_runtime_t * node,
3033 vlib_frame_t * from_frame)
3035 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3038 VLIB_NODE_FN (tcp6_rcv_process_node) (vlib_main_t * vm,
3039 vlib_node_runtime_t * node,
3040 vlib_frame_t * from_frame)
3042 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3046 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
3048 .name = "tcp4-rcv-process",
3049 /* Takes a vector of packets. */
3050 .vector_size = sizeof (u32),
3051 .n_errors = TCP_N_ERROR,
3052 .error_strings = tcp_error_strings,
3053 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3056 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3057 foreach_tcp_state_next
3060 .format_trace = format_tcp_rx_trace_short,
3065 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
3067 .name = "tcp6-rcv-process",
3068 /* Takes a vector of packets. */
3069 .vector_size = sizeof (u32),
3070 .n_errors = TCP_N_ERROR,
3071 .error_strings = tcp_error_strings,
3072 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3075 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3076 foreach_tcp_state_next
3079 .format_trace = format_tcp_rx_trace_short,
3084 * LISTEN state processing as per RFC 793 p. 65
3087 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3088 vlib_frame_t * from_frame, int is_ip4)
3090 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3091 u32 my_thread_index = vm->thread_index;
3093 from = first_buffer = vlib_frame_vector_args (from_frame);
3094 n_left_from = from_frame->n_vectors;
3096 while (n_left_from > 0)
3101 tcp_header_t *th0 = 0;
3102 tcp_connection_t *lc0;
3105 tcp_connection_t *child0;
3106 u32 error0 = TCP_ERROR_NONE;
3112 b0 = vlib_get_buffer (vm, bi0);
3113 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3117 ip40 = vlib_buffer_get_current (b0);
3118 th0 = ip4_next_header (ip40);
3122 ip60 = vlib_buffer_get_current (b0);
3123 th0 = ip6_next_header (ip60);
3126 /* Create child session. For syn-flood protection use filter */
3128 /* 1. first check for an RST: handled in dispatch */
3129 /* if (tcp_rst (th0))
3133 /* 2. second check for an ACK: handled in dispatch */
3134 /* if (tcp_ack (th0))
3136 tcp_send_reset (b0, is_ip4);
3141 /* 3. check for a SYN (did that already) */
3143 /* Make sure connection wasn't just created */
3144 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3146 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3148 error0 = TCP_ERROR_CREATE_EXISTS;
3152 /* Create child session and send SYN-ACK */
3153 child0 = tcp_connection_alloc (my_thread_index);
3154 child0->c_lcl_port = th0->dst_port;
3155 child0->c_rmt_port = th0->src_port;
3156 child0->c_is_ip4 = is_ip4;
3157 child0->state = TCP_STATE_SYN_RCVD;
3158 child0->c_fib_index = lc0->c_fib_index;
3162 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3163 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3167 clib_memcpy_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3168 sizeof (ip6_address_t));
3169 clib_memcpy_fast (&child0->c_rmt_ip6, &ip60->src_address,
3170 sizeof (ip6_address_t));
3173 if (tcp_options_parse (th0, &child0->rcv_opts, 1))
3175 error0 = TCP_ERROR_OPTIONS;
3176 tcp_connection_free (child0);
3180 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3181 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3182 child0->rcv_las = child0->rcv_nxt;
3183 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3185 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3186 * segments are used to initialize PAWS. */
3187 if (tcp_opts_tstamp (&child0->rcv_opts))
3189 child0->tsval_recent = child0->rcv_opts.tsval;
3190 child0->tsval_recent_age = tcp_time_now ();
3193 if (tcp_opts_wscale (&child0->rcv_opts))
3194 child0->snd_wscale = child0->rcv_opts.wscale;
3196 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3197 << child0->snd_wscale;
3198 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3199 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3201 tcp_connection_init_vars (child0);
3202 child0->rto = TCP_RTO_MIN;
3204 if (session_stream_accept (&child0->connection, lc0->c_s_index,
3205 lc0->c_thread_index, 0 /* notify */ ))
3207 tcp_connection_cleanup (child0);
3208 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3212 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
3213 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3214 tcp_send_synack (child0);
3215 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
3219 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3221 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3222 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3223 clib_memcpy_fast (&t0->tcp_connection, lc0,
3224 sizeof (t0->tcp_connection));
3227 n_syns += (error0 == TCP_ERROR_NONE);
3230 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3231 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3233 return from_frame->n_vectors;
3236 VLIB_NODE_FN (tcp4_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3237 vlib_frame_t * from_frame)
3239 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3242 VLIB_NODE_FN (tcp6_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3243 vlib_frame_t * from_frame)
3245 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3249 VLIB_REGISTER_NODE (tcp4_listen_node) =
3251 .name = "tcp4-listen",
3252 /* Takes a vector of packets. */
3253 .vector_size = sizeof (u32),
3254 .n_errors = TCP_N_ERROR,
3255 .error_strings = tcp_error_strings,
3256 .n_next_nodes = TCP_LISTEN_N_NEXT,
3259 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3260 foreach_tcp_state_next
3263 .format_trace = format_tcp_rx_trace_short,
3268 VLIB_REGISTER_NODE (tcp6_listen_node) =
3270 .name = "tcp6-listen",
3271 /* Takes a vector of packets. */
3272 .vector_size = sizeof (u32),
3273 .n_errors = TCP_N_ERROR,
3274 .error_strings = tcp_error_strings,
3275 .n_next_nodes = TCP_LISTEN_N_NEXT,
3278 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3279 foreach_tcp_state_next
3282 .format_trace = format_tcp_rx_trace_short,
3286 typedef enum _tcp_input_next
3288 TCP_INPUT_NEXT_DROP,
3289 TCP_INPUT_NEXT_LISTEN,
3290 TCP_INPUT_NEXT_RCV_PROCESS,
3291 TCP_INPUT_NEXT_SYN_SENT,
3292 TCP_INPUT_NEXT_ESTABLISHED,
3293 TCP_INPUT_NEXT_RESET,
3294 TCP_INPUT_NEXT_PUNT,
3298 #define foreach_tcp4_input_next \
3299 _ (DROP, "ip4-drop") \
3300 _ (LISTEN, "tcp4-listen") \
3301 _ (RCV_PROCESS, "tcp4-rcv-process") \
3302 _ (SYN_SENT, "tcp4-syn-sent") \
3303 _ (ESTABLISHED, "tcp4-established") \
3304 _ (RESET, "tcp4-reset") \
3305 _ (PUNT, "ip4-punt")
3307 #define foreach_tcp6_input_next \
3308 _ (DROP, "ip6-drop") \
3309 _ (LISTEN, "tcp6-listen") \
3310 _ (RCV_PROCESS, "tcp6-rcv-process") \
3311 _ (SYN_SENT, "tcp6-syn-sent") \
3312 _ (ESTABLISHED, "tcp6-established") \
3313 _ (RESET, "tcp6-reset") \
3314 _ (PUNT, "ip6-punt")
3316 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3319 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3320 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3322 tcp_connection_t *tc;
3327 for (i = 0; i < n_bufs; i++)
3329 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3331 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3332 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3334 tcp = vlib_buffer_get_current (bs[i]);
3335 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3341 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3343 if (*error == TCP_ERROR_FILTERED || *error == TCP_ERROR_WRONG_THREAD)
3345 *next = TCP_INPUT_NEXT_DROP;
3347 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3349 *next = TCP_INPUT_NEXT_PUNT;
3350 *error = TCP_ERROR_PUNT;
3354 *next = TCP_INPUT_NEXT_RESET;
3355 *error = TCP_ERROR_NO_LISTENER;
3359 static inline tcp_connection_t *
3360 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3363 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3364 int n_advance_bytes, n_data_bytes;
3365 transport_connection_t *tc;
3371 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3372 int ip_hdr_bytes = ip4_header_bytes (ip4);
3373 if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
3375 *error = TCP_ERROR_LENGTH;
3378 tcp = ip4_next_header (ip4);
3379 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3380 n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
3381 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3383 /* Length check. Checksum computed by ipx_local no need to compute again */
3384 if (PREDICT_FALSE (n_data_bytes < 0))
3386 *error = TCP_ERROR_LENGTH;
3390 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3391 &ip4->src_address, tcp->dst_port,
3392 tcp->src_port, TRANSPORT_PROTO_TCP,
3393 thread_index, &result);
3397 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3398 if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
3400 *error = TCP_ERROR_LENGTH;
3403 tcp = ip6_next_header (ip6);
3404 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3405 n_advance_bytes = tcp_header_bytes (tcp);
3406 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3408 n_advance_bytes += sizeof (ip6[0]);
3410 if (PREDICT_FALSE (n_data_bytes < 0))
3412 *error = TCP_ERROR_LENGTH;
3416 (ip6_address_is_link_local_unicast (&ip6->dst_address)))
3418 ip4_main_t *im = &ip4_main;
3419 fib_index = vec_elt (im->fib_index_by_sw_if_index,
3420 vnet_buffer (b)->sw_if_index[VLIB_RX]);
3423 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3424 &ip6->src_address, tcp->dst_port,
3425 tcp->src_port, TRANSPORT_PROTO_TCP,
3426 thread_index, &result);
3429 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3430 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3431 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3432 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3433 vnet_buffer (b)->tcp.seq_end = vnet_buffer (b)->tcp.seq_number
3435 vnet_buffer (b)->tcp.flags = 0;
3437 *error = result ? TCP_ERROR_NONE + result : *error;
3439 return tcp_get_connection_from_transport (tc);
3443 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3444 vlib_buffer_t * b, u16 * next, u32 * error)
3449 tcp = tcp_buffer_hdr (b);
3450 flags = tcp->flags & filter_flags;
3451 *next = tm->dispatch_table[tc->state][flags].next;
3452 *error = tm->dispatch_table[tc->state][flags].error;
3454 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3455 || *next == TCP_INPUT_NEXT_RESET))
3457 /* Overload tcp flags to store state */
3458 tcp_state_t state = tc->state;
3459 vnet_buffer (b)->tcp.flags = tc->state;
3461 if (*error == TCP_ERROR_DISPATCH)
3462 clib_warning ("tcp conn %u disp error state %U flags %U",
3463 tc->c_c_index, format_tcp_state, state,
3464 format_tcp_flags, (int) flags);
3469 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3470 vlib_frame_t * frame, int is_ip4)
3472 u32 n_left_from, *from, thread_index = vm->thread_index;
3473 tcp_main_t *tm = vnet_get_tcp_main ();
3474 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3475 u16 nexts[VLIB_FRAME_SIZE], *next;
3477 tcp_set_time_now (tcp_get_worker (thread_index));
3479 from = vlib_frame_vector_args (frame);
3480 n_left_from = frame->n_vectors;
3481 vlib_get_buffers (vm, from, bufs, n_left_from);
3486 while (n_left_from >= 4)
3488 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3489 tcp_connection_t *tc0, *tc1;
3492 vlib_prefetch_buffer_header (b[2], STORE);
3493 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3495 vlib_prefetch_buffer_header (b[3], STORE);
3496 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3499 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3501 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3502 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4);
3504 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3506 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3507 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3509 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3510 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3512 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3513 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3517 if (PREDICT_TRUE (tc0 != 0))
3519 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3520 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3521 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3524 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3526 if (PREDICT_TRUE (tc1 != 0))
3528 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3529 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3530 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3533 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3540 while (n_left_from > 0)
3542 tcp_connection_t *tc0;
3543 u32 error0 = TCP_ERROR_NO_LISTENER;
3545 if (n_left_from > 1)
3547 vlib_prefetch_buffer_header (b[1], STORE);
3548 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3551 next[0] = TCP_INPUT_NEXT_DROP;
3552 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3553 if (PREDICT_TRUE (tc0 != 0))
3555 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3556 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3557 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3560 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3567 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3568 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3570 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3571 return frame->n_vectors;
3574 VLIB_NODE_FN (tcp4_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3575 vlib_frame_t * from_frame)
3577 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3580 VLIB_NODE_FN (tcp6_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3581 vlib_frame_t * from_frame)
3583 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3587 VLIB_REGISTER_NODE (tcp4_input_node) =
3589 .name = "tcp4-input",
3590 /* Takes a vector of packets. */
3591 .vector_size = sizeof (u32),
3592 .n_errors = TCP_N_ERROR,
3593 .error_strings = tcp_error_strings,
3594 .n_next_nodes = TCP_INPUT_N_NEXT,
3597 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3598 foreach_tcp4_input_next
3601 .format_buffer = format_tcp_header,
3602 .format_trace = format_tcp_rx_trace,
3607 VLIB_REGISTER_NODE (tcp6_input_node) =
3609 .name = "tcp6-input",
3610 /* Takes a vector of packets. */
3611 .vector_size = sizeof (u32),
3612 .n_errors = TCP_N_ERROR,
3613 .error_strings = tcp_error_strings,
3614 .n_next_nodes = TCP_INPUT_N_NEXT,
3617 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3618 foreach_tcp6_input_next
3621 .format_buffer = format_tcp_header,
3622 .format_trace = format_tcp_rx_trace,
3626 #ifndef CLIB_MARCH_VARIANT
3628 tcp_dispatch_table_init (tcp_main_t * tm)
3631 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3632 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3634 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3635 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3638 #define _(t,f,n,e) \
3640 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3641 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3644 /* RFC 793: In LISTEN if RST drop and if ACK return RST */
3645 _(LISTEN, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3646 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_ACK_INVALID);
3647 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_INVALID_CONNECTION);
3648 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3649 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3650 TCP_ERROR_ACK_INVALID);
3651 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3652 TCP_ERROR_SEGMENT_INVALID);
3653 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3654 TCP_ERROR_SEGMENT_INVALID);
3655 _(LISTEN, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3656 TCP_ERROR_INVALID_CONNECTION);
3657 _(LISTEN, TCP_FLAG_FIN, TCP_INPUT_NEXT_RESET, TCP_ERROR_SEGMENT_INVALID);
3658 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3659 TCP_ERROR_SEGMENT_INVALID);
3660 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3661 TCP_ERROR_SEGMENT_INVALID);
3662 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3664 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_DROP,
3665 TCP_ERROR_SEGMENT_INVALID);
3666 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3667 TCP_ERROR_SEGMENT_INVALID);
3668 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3669 TCP_ERROR_SEGMENT_INVALID);
3670 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3671 TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3672 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3673 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3674 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3675 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3677 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3678 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3680 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3682 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3683 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3684 _(SYN_RCVD, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3685 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3687 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3689 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3690 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3691 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3693 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3694 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3695 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3696 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3697 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3698 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3699 _(SYN_RCVD, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3700 /* SYN-ACK for a SYN */
3701 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3703 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3704 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3705 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3707 _(SYN_SENT, TCP_FLAG_FIN, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3708 _(SYN_SENT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3710 /* ACK for for established connection -> tcp-established. */
3711 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3712 /* FIN for for established connection -> tcp-established. */
3713 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3714 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3716 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3718 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3719 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3720 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED,
3722 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3723 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3724 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3725 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3726 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3727 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3728 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3729 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3731 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3732 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3734 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3736 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3737 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3738 _(ESTABLISHED, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3739 /* ACK or FIN-ACK to our FIN */
3740 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3741 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3743 /* FIN in reply to our FIN from the other side */
3744 _(FIN_WAIT_1, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3745 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3746 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3748 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3749 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3750 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3751 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3752 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3753 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3754 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3756 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3757 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3758 _(FIN_WAIT_1, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3759 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3761 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3763 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3764 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3765 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3766 _(FIN_WAIT_1, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3768 _(CLOSING, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3769 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3770 _(CLOSING, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3771 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3773 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3775 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3776 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3777 _(CLOSING, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3778 _(CLOSING, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3780 _(CLOSING, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3781 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3783 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3785 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3786 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3787 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3789 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3790 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3791 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3792 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3793 /* FIN confirming that the peer (app) has closed */
3794 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3795 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3796 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3798 _(FIN_WAIT_2, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3799 _(FIN_WAIT_2, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3801 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3802 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3804 _(CLOSE_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3805 _(CLOSE_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3807 _(LAST_ACK, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3808 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3809 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3810 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3812 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3814 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3815 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3816 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3818 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3819 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3820 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3821 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3822 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3823 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3824 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3825 _(LAST_ACK, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3827 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3828 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3830 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3832 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3833 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3834 _(TIME_WAIT, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3835 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3836 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3838 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3839 _(TIME_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3841 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3842 /* RFC793 CLOSED: An incoming segment containing a RST is discarded. An
3843 * incoming segment not containing a RST causes a RST to be sent in
3845 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3846 _(CLOSED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3847 TCP_ERROR_CONNECTION_CLOSED);
3848 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3849 _(CLOSED, TCP_FLAG_SYN, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3850 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3855 static clib_error_t *
3856 tcp_input_init (vlib_main_t * vm)
3858 clib_error_t *error = 0;
3859 tcp_main_t *tm = vnet_get_tcp_main ();
3861 if ((error = vlib_call_init_function (vm, tcp_init)))
3864 /* Initialize dispatch table. */
3865 tcp_dispatch_table_init (tm);
3870 VLIB_INIT_FUNCTION (tcp_input_init);
3872 #endif /* CLIB_MARCH_VARIANT */
3875 * fd.io coding-style-patch-verification: ON
3878 * eval: (c-set-style "gnu")