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/fib/ip4_fib.h>
18 #include <vnet/fib/ip6_fib.h>
19 #include <vnet/tcp/tcp_packet.h>
20 #include <vnet/tcp/tcp.h>
21 #include <vnet/session/session.h>
24 static char *tcp_error_strings[] = {
25 #define tcp_error(n,s) s,
26 #include <vnet/tcp/tcp_error.def>
30 /* All TCP nodes have the same outgoing arcs */
31 #define foreach_tcp_state_next \
32 _ (DROP4, "ip4-drop") \
33 _ (DROP6, "ip6-drop") \
34 _ (TCP4_OUTPUT, "tcp4-output") \
35 _ (TCP6_OUTPUT, "tcp6-output")
37 typedef enum _tcp_established_next
39 #define _(s,n) TCP_ESTABLISHED_NEXT_##s,
40 foreach_tcp_state_next
42 TCP_ESTABLISHED_N_NEXT,
43 } tcp_established_next_t;
45 typedef enum _tcp_rcv_process_next
47 #define _(s,n) TCP_RCV_PROCESS_NEXT_##s,
48 foreach_tcp_state_next
50 TCP_RCV_PROCESS_N_NEXT,
51 } tcp_rcv_process_next_t;
53 typedef enum _tcp_syn_sent_next
55 #define _(s,n) TCP_SYN_SENT_NEXT_##s,
56 foreach_tcp_state_next
59 } tcp_syn_sent_next_t;
61 typedef enum _tcp_listen_next
63 #define _(s,n) TCP_LISTEN_NEXT_##s,
64 foreach_tcp_state_next
69 /* Generic, state independent indices */
70 typedef enum _tcp_state_next
72 #define _(s,n) TCP_NEXT_##s,
73 foreach_tcp_state_next
78 #define tcp_next_output(is_ip4) (is_ip4 ? TCP_NEXT_TCP4_OUTPUT \
79 : TCP_NEXT_TCP6_OUTPUT)
81 #define tcp_next_drop(is_ip4) (is_ip4 ? TCP_NEXT_DROP4 \
85 * Validate segment sequence number. As per RFC793:
87 * Segment Receive Test
89 * ------- ------- -------------------------------------------
90 * 0 0 SEG.SEQ = RCV.NXT
91 * 0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
93 * >0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
94 * or RCV.NXT =< SEG.SEQ+SEG.LEN-1 < RCV.NXT+RCV.WND
96 * This ultimately consists in checking if segment falls within the window.
97 * The one important difference compared to RFC793 is that we use rcv_las,
98 * or the rcv_nxt at last ack sent instead of rcv_nxt since that's the
99 * peer's reference when computing our receive window.
102 * seq_leq (end_seq, tc->rcv_las + tc->rcv_wnd) && seq_geq (seq, tc->rcv_las)
103 * however, is too strict when we have retransmits. Instead we just check that
104 * the seq is not beyond the right edge and that the end of the segment is not
105 * less than the left edge.
107 * N.B. rcv_nxt and rcv_wnd are both updated in this node if acks are sent, so
108 * use rcv_nxt in the right edge window test instead of rcv_las.
112 tcp_segment_in_rcv_wnd (tcp_connection_t * tc, u32 seq, u32 end_seq)
114 return (seq_geq (end_seq, tc->rcv_las)
115 && seq_leq (seq, tc->rcv_nxt + tc->rcv_wnd));
119 * Parse TCP header options.
121 * @param th TCP header
122 * @param to TCP options data structure to be populated
123 * @param is_syn set if packet is syn
124 * @return -1 if parsing failed
127 tcp_options_parse (tcp_header_t * th, tcp_options_t * to, u8 is_syn)
130 u8 opt_len, opts_len, kind;
134 opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t);
135 data = (const u8 *) (th + 1);
137 /* Zero out all flags but those set in SYN */
138 to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE
139 | TCP_OPTS_FLAG_TSTAMP | TCP_OPTION_MSS);
141 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
145 /* Get options length */
146 if (kind == TCP_OPTION_EOL)
148 else if (kind == TCP_OPTION_NOOP)
160 /* weird option length */
161 if (opt_len < 2 || opt_len > opts_len)
171 if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
173 to->flags |= TCP_OPTS_FLAG_MSS;
174 to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
177 case TCP_OPTION_WINDOW_SCALE:
180 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
182 to->flags |= TCP_OPTS_FLAG_WSCALE;
183 to->wscale = data[2];
184 if (to->wscale > TCP_MAX_WND_SCALE)
185 to->wscale = TCP_MAX_WND_SCALE;
188 case TCP_OPTION_TIMESTAMP:
190 to->flags |= TCP_OPTS_FLAG_TSTAMP;
191 if ((to->flags & TCP_OPTS_FLAG_TSTAMP)
192 && opt_len == TCP_OPTION_LEN_TIMESTAMP)
194 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
195 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
198 case TCP_OPTION_SACK_PERMITTED:
201 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
202 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
204 case TCP_OPTION_SACK_BLOCK:
205 /* If SACK permitted was not advertised or a SYN, break */
206 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
209 /* If too short or not correctly formatted, break */
210 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
213 to->flags |= TCP_OPTS_FLAG_SACK;
214 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
215 vec_reset_length (to->sacks);
216 for (j = 0; j < to->n_sack_blocks; j++)
218 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 8 * j));
219 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 8 * j));
220 vec_add1 (to->sacks, b);
224 /* Nothing to see here */
232 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
233 * timestamp to echo and it's less than tsval_recent, drop segment
234 * but still send an ACK in order to retain TCP's mechanism for detecting
235 * and recovering from half-open connections
237 * Or at least that's what the theory says. It seems that this might not work
238 * very well with packet reordering and fast retransmit. XXX
241 tcp_segment_check_paws (tcp_connection_t * tc)
243 return tcp_opts_tstamp (&tc->rcv_opts)
244 && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent);
248 * Update tsval recent
251 tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
254 * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
255 * of an incoming segment:
256 * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
257 * then the TSval from the segment is copied to TS.Recent;
258 * otherwise, the TSval is ignored.
260 if (tcp_opts_tstamp (&tc->rcv_opts) && seq_leq (seq, tc->rcv_las)
261 && seq_leq (tc->rcv_las, seq_end))
263 ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval));
264 tc->tsval_recent = tc->rcv_opts.tsval;
265 tc->tsval_recent_age = tcp_time_now_w_thread (tc->c_thread_index);
270 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
272 * It first verifies if segment has a wrapped sequence number (PAWS) and then
273 * does the processing associated to the first four steps (ignoring security
274 * and precedence): sequence number, rst bit and syn bit checks.
276 * @return 0 if segments passes validation.
279 tcp_segment_validate (tcp_worker_ctx_t * wrk, tcp_connection_t * tc0,
280 vlib_buffer_t * b0, tcp_header_t * th0, u32 * error0)
282 /* We could get a burst of RSTs interleaved with acks */
283 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
285 tcp_send_reset (tc0);
286 *error0 = TCP_ERROR_CONNECTION_CLOSED;
290 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
292 *error0 = TCP_ERROR_SEGMENT_INVALID;
296 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts, 0)))
298 *error0 = TCP_ERROR_OPTIONS;
302 if (PREDICT_FALSE (tcp_segment_check_paws (tc0)))
304 *error0 = TCP_ERROR_PAWS;
305 TCP_EVT (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
306 vnet_buffer (b0)->tcp.seq_end);
308 /* If it just so happens that a segment updates tsval_recent for a
309 * segment over 24 days old, invalidate tsval_recent. */
310 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
311 tcp_time_now_w_thread (tc0->c_thread_index)))
313 tc0->tsval_recent = tc0->rcv_opts.tsval;
314 clib_warning ("paws failed: 24-day old segment");
316 /* Drop after ack if not rst. Resets can fail paws check as per
317 * RFC 7323 sec. 5.2: When an <RST> segment is received, it MUST NOT
318 * be subjected to the PAWS check by verifying an acceptable value in
320 else if (!tcp_rst (th0))
322 tcp_program_ack (tc0);
323 TCP_EVT (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
328 /* 1st: check sequence number */
329 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
330 vnet_buffer (b0)->tcp.seq_end))
332 /* SYN/SYN-ACK retransmit */
334 && vnet_buffer (b0)->tcp.seq_number == tc0->rcv_nxt - 1)
336 tcp_options_parse (th0, &tc0->rcv_opts, 1);
337 if (tc0->state == TCP_STATE_SYN_RCVD)
339 tcp_send_synack (tc0);
340 TCP_EVT (TCP_EVT_SYN_RCVD, tc0, 0);
341 *error0 = TCP_ERROR_SYNS_RCVD;
345 tcp_program_ack (tc0);
346 TCP_EVT (TCP_EVT_SYNACK_RCVD, tc0);
347 *error0 = TCP_ERROR_SYN_ACKS_RCVD;
352 /* If our window is 0 and the packet is in sequence, let it pass
353 * through for ack processing. It should be dropped later. */
354 if (tc0->rcv_wnd < tc0->snd_mss
355 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number)
358 /* If we entered recovery and peer did so as well, there's a chance that
359 * dup acks won't be acceptable on either end because seq_end may be less
360 * than rcv_las. This can happen if acks are lost in both directions. */
361 if (tcp_in_recovery (tc0)
362 && seq_geq (vnet_buffer (b0)->tcp.seq_number,
363 tc0->rcv_las - tc0->rcv_wnd)
364 && seq_leq (vnet_buffer (b0)->tcp.seq_end,
365 tc0->rcv_nxt + tc0->rcv_wnd))
368 *error0 = TCP_ERROR_RCV_WND;
370 /* If we advertised a zero rcv_wnd and the segment is in the past or the
371 * next one that we expect, it is probably a window probe */
372 if ((tc0->flags & TCP_CONN_ZERO_RWND_SENT)
373 && seq_lt (vnet_buffer (b0)->tcp.seq_end,
374 tc0->rcv_las + tc0->rcv_opts.mss))
375 *error0 = TCP_ERROR_ZERO_RWND;
377 tc0->errors.below_data_wnd += seq_lt (vnet_buffer (b0)->tcp.seq_end,
380 /* If not RST, send dup ack */
383 tcp_program_dupack (tc0);
384 TCP_EVT (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
392 /* 2nd: check the RST bit */
393 if (PREDICT_FALSE (tcp_rst (th0)))
395 tcp_connection_reset (tc0);
396 *error0 = TCP_ERROR_RST_RCVD;
400 /* 3rd: check security and precedence (skip) */
402 /* 4th: check the SYN bit (in window) */
403 if (PREDICT_FALSE (tcp_syn (th0)))
405 /* As per RFC5961 send challenge ack instead of reset */
406 tcp_program_ack (tc0);
407 *error0 = TCP_ERROR_SPURIOUS_SYN;
411 /* If segment in window, save timestamp */
412 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
413 vnet_buffer (b0)->tcp.seq_end);
421 tcp_rcv_ack_no_cc (tcp_connection_t * tc, vlib_buffer_t * b, u32 * error)
423 /* SND.UNA =< SEG.ACK =< SND.NXT */
424 if (!(seq_leq (tc->snd_una, vnet_buffer (b)->tcp.ack_number)
425 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
427 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)
428 && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
430 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
433 *error = TCP_ERROR_ACK_INVALID;
438 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
439 tc->snd_una = vnet_buffer (b)->tcp.ack_number;
440 *error = TCP_ERROR_ACK_OK;
445 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
447 * Note that although the original article, srtt and rttvar are scaled
448 * to minimize round-off errors, here we don't. Instead, we rely on
449 * better precision time measurements.
451 * TODO support us rtt resolution
454 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
460 err = mrtt - tc->srtt;
462 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
463 * The increase should be bound */
464 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
465 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
466 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
470 /* First measurement. */
472 tc->rttvar = mrtt >> 1;
476 #ifndef CLIB_MARCH_VARIANT
478 tcp_update_rto (tcp_connection_t * tc)
480 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
481 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
483 #endif /* CLIB_MARCH_VARIANT */
486 * Update RTT estimate and RTO timer
488 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
489 * timing. Middle boxes are known to fiddle with TCP options so we
490 * should give higher priority to ACK timing.
492 * This should be called only if previously sent bytes have been acked.
494 * return 1 if valid rtt 0 otherwise
497 tcp_update_rtt (tcp_connection_t * tc, tcp_rate_sample_t * rs, u32 ack)
501 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
502 * RTT because they're ambiguous. */
503 if (tcp_in_cong_recovery (tc))
505 /* Accept rtt estimates for samples that have not been retransmitted */
506 if ((tc->flags & TCP_CONN_RATE_SAMPLE) && !(rs->flags & TCP_BTS_IS_RXT))
508 mrtt = rs->rtt_time * THZ;
514 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
516 f64 sample = tcp_time_now_us (tc->c_thread_index) - tc->rtt_ts;
517 tc->mrtt_us = tc->mrtt_us + (sample - tc->mrtt_us) * 0.125;
518 mrtt = clib_max ((u32) (sample * THZ), 1);
519 /* Allow measuring of a new RTT */
522 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
523 * snd_una, i.e., the left side of the send window:
524 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
525 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
527 u32 now = tcp_tstamp (tc);
528 mrtt = clib_max (now - tc->rcv_opts.tsecr, 1);
533 /* Ignore dubious measurements */
534 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
537 tcp_estimate_rtt (tc, mrtt);
541 /* If we got here something must've been ACKed so make sure boff is 0,
542 * even if mrtt is not valid since we update the rto lower */
550 tcp_estimate_initial_rtt (tcp_connection_t * tc)
552 u8 thread_index = vlib_num_workers ()? 1 : 0;
557 tc->mrtt_us = tcp_time_now_us (thread_index) - tc->rtt_ts;
558 tc->mrtt_us = clib_max (tc->mrtt_us, 0.0001);
559 mrtt = clib_max ((u32) (tc->mrtt_us * THZ), 1);
564 mrtt = tcp_time_now_w_thread (thread_index) - tc->rcv_opts.tsecr;
565 mrtt = clib_max (mrtt, 1);
566 /* Due to retransmits we don't know the initial mrtt */
567 if (tc->rto_boff && mrtt > 1 * THZ)
569 tc->mrtt_us = (f64) mrtt *TCP_TICK;
572 if (mrtt > 0 && mrtt < TCP_RTT_MAX)
573 tcp_estimate_rtt (tc, mrtt);
578 * Dequeue bytes for connections that have received acks in last burst
581 tcp_handle_postponed_dequeues (tcp_worker_ctx_t * wrk)
583 u32 thread_index = wrk->vm->thread_index;
584 u32 *pending_deq_acked;
585 tcp_connection_t *tc;
588 if (!vec_len (wrk->pending_deq_acked))
591 pending_deq_acked = wrk->pending_deq_acked;
592 for (i = 0; i < vec_len (pending_deq_acked); i++)
594 tc = tcp_connection_get (pending_deq_acked[i], thread_index);
595 tc->flags &= ~TCP_CONN_DEQ_PENDING;
597 if (PREDICT_FALSE (!tc->burst_acked))
600 /* Dequeue the newly ACKed bytes */
601 session_tx_fifo_dequeue_drop (&tc->connection, tc->burst_acked);
603 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
605 if (PREDICT_FALSE (tc->flags & TCP_CONN_PSH_PENDING))
607 if (seq_leq (tc->psh_seq, tc->snd_una))
608 tc->flags &= ~TCP_CONN_PSH_PENDING;
611 /* If everything has been acked, stop retransmit timer
612 * otherwise update. */
613 tcp_retransmit_timer_update (tc);
615 /* Update pacer based on our new cwnd estimate */
616 tcp_connection_tx_pacer_update (tc);
618 _vec_len (wrk->pending_deq_acked) = 0;
622 tcp_program_dequeue (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
624 if (!(tc->flags & TCP_CONN_DEQ_PENDING))
626 vec_add1 (wrk->pending_deq_acked, tc->c_c_index);
627 tc->flags |= TCP_CONN_DEQ_PENDING;
629 tc->burst_acked += tc->bytes_acked;
632 #ifndef CLIB_MARCH_VARIANT
634 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
636 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
637 return hole - sb->holes;
641 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
643 return hole->end - hole->start;
646 sack_scoreboard_hole_t *
647 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
649 if (index != TCP_INVALID_SACK_HOLE_INDEX)
650 return pool_elt_at_index (sb->holes, index);
654 sack_scoreboard_hole_t *
655 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
657 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
658 return pool_elt_at_index (sb->holes, hole->next);
662 sack_scoreboard_hole_t *
663 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
665 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
666 return pool_elt_at_index (sb->holes, hole->prev);
670 sack_scoreboard_hole_t *
671 scoreboard_first_hole (sack_scoreboard_t * sb)
673 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
674 return pool_elt_at_index (sb->holes, sb->head);
678 sack_scoreboard_hole_t *
679 scoreboard_last_hole (sack_scoreboard_t * sb)
681 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
682 return pool_elt_at_index (sb->holes, sb->tail);
687 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
689 sack_scoreboard_hole_t *next, *prev;
691 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
693 next = pool_elt_at_index (sb->holes, hole->next);
694 next->prev = hole->prev;
698 sb->tail = hole->prev;
701 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
703 prev = pool_elt_at_index (sb->holes, hole->prev);
704 prev->next = hole->next;
708 sb->head = hole->next;
711 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
712 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
714 /* Poison the entry */
716 clib_memset (hole, 0xfe, sizeof (*hole));
718 pool_put (sb->holes, hole);
721 static sack_scoreboard_hole_t *
722 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
725 sack_scoreboard_hole_t *hole, *next, *prev;
728 pool_get (sb->holes, hole);
729 clib_memset (hole, 0, sizeof (*hole));
733 hole_index = scoreboard_hole_index (sb, hole);
735 prev = scoreboard_get_hole (sb, prev_index);
738 hole->prev = prev_index;
739 hole->next = prev->next;
741 if ((next = scoreboard_next_hole (sb, hole)))
742 next->prev = hole_index;
744 sb->tail = hole_index;
746 prev->next = hole_index;
750 sb->head = hole_index;
751 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
752 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
759 scoreboard_update_sacked_rxt (sack_scoreboard_t * sb, u32 start, u32 end,
762 if (!has_rxt || seq_geq (start, sb->high_rxt))
766 seq_lt (end, sb->high_rxt) ? (end - start) : (sb->high_rxt - start);
770 scoreboard_update_bytes (sack_scoreboard_t * sb, u32 ack, u32 snd_mss)
772 sack_scoreboard_hole_t *left, *right;
773 u32 sacked = 0, blks = 0, old_sacked;
775 old_sacked = sb->sacked_bytes;
777 sb->last_lost_bytes = 0;
779 sb->sacked_bytes = 0;
781 right = scoreboard_last_hole (sb);
784 sb->sacked_bytes = sb->high_sacked - ack;
788 if (seq_gt (sb->high_sacked, right->end))
790 sacked = sb->high_sacked - right->end;
794 while (sacked < (TCP_DUPACK_THRESHOLD - 1) * snd_mss
795 && blks < TCP_DUPACK_THRESHOLD)
798 sb->lost_bytes += scoreboard_hole_bytes (right);
800 left = scoreboard_prev_hole (sb, right);
803 ASSERT (right->start == ack || sb->is_reneging);
804 sacked += right->start - ack;
809 sacked += right->start - left->end;
814 /* right is first lost */
817 sb->lost_bytes += scoreboard_hole_bytes (right);
818 sb->last_lost_bytes += right->is_lost ? 0 : (right->end - right->start);
820 left = scoreboard_prev_hole (sb, right);
823 ASSERT (right->start == ack || sb->is_reneging);
824 sacked += right->start - ack;
827 sacked += right->start - left->end;
831 sb->sacked_bytes = sacked;
832 sb->last_sacked_bytes = sacked - (old_sacked - sb->last_bytes_delivered);
836 * Figure out the next hole to retransmit
838 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
840 sack_scoreboard_hole_t *
841 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
842 sack_scoreboard_hole_t * start,
843 u8 have_unsent, u8 * can_rescue, u8 * snd_limited)
845 sack_scoreboard_hole_t *hole = 0;
847 hole = start ? start : scoreboard_first_hole (sb);
848 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
849 hole = scoreboard_next_hole (sb, hole);
851 /* Nothing, return */
854 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
858 /* Rule (1): if higher than rxt, less than high_sacked and lost */
859 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
861 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
865 /* Rule (2): available unsent data */
868 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
871 /* Rule (3): if hole not lost */
872 else if (seq_lt (hole->start, sb->high_sacked))
875 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
877 /* Rule (4): if hole beyond high_sacked */
880 ASSERT (seq_geq (hole->start, sb->high_sacked));
883 /* HighRxt MUST NOT be updated */
888 if (hole && seq_lt (sb->high_rxt, hole->start))
889 sb->high_rxt = hole->start;
895 scoreboard_init_rxt (sack_scoreboard_t * sb, u32 snd_una)
897 sack_scoreboard_hole_t *hole;
898 hole = scoreboard_first_hole (sb);
901 snd_una = seq_gt (snd_una, hole->start) ? snd_una : hole->start;
902 sb->cur_rxt_hole = sb->head;
904 sb->high_rxt = snd_una;
905 sb->rescue_rxt = snd_una - 1;
909 scoreboard_init (sack_scoreboard_t * sb)
911 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
912 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
913 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
917 scoreboard_clear (sack_scoreboard_t * sb)
919 sack_scoreboard_hole_t *hole;
920 while ((hole = scoreboard_first_hole (sb)))
922 scoreboard_remove_hole (sb, hole);
924 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
925 ASSERT (pool_elts (sb->holes) == 0);
926 sb->sacked_bytes = 0;
927 sb->last_sacked_bytes = 0;
928 sb->last_bytes_delivered = 0;
932 sb->last_lost_bytes = 0;
933 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
938 scoreboard_clear_reneging (sack_scoreboard_t * sb, u32 start, u32 end)
940 sack_scoreboard_hole_t *last_hole;
942 clib_warning ("sack reneging");
944 scoreboard_clear (sb);
945 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
947 last_hole->is_lost = 1;
948 sb->tail = scoreboard_hole_index (sb, last_hole);
949 sb->high_sacked = start;
950 scoreboard_init_rxt (sb, start);
953 #endif /* CLIB_MARCH_VARIANT */
956 * Test that scoreboard is sane after recovery
958 * Returns 1 if scoreboard is empty or if first hole beyond
962 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
964 sack_scoreboard_hole_t *hole;
965 hole = scoreboard_first_hole (&tc->sack_sb);
966 return (!hole || (seq_geq (hole->start, tc->snd_una)
967 && seq_lt (hole->end, tc->snd_nxt)));
970 #ifndef CLIB_MARCH_VARIANT
973 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
975 sack_scoreboard_hole_t *hole, *next_hole;
976 sack_scoreboard_t *sb = &tc->sack_sb;
977 sack_block_t *blk, *rcv_sacks;
978 u32 blk_index = 0, i, j;
981 sb->last_sacked_bytes = 0;
982 sb->last_bytes_delivered = 0;
985 if (!tcp_opts_sack (&tc->rcv_opts)
986 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
989 has_rxt = tcp_in_cong_recovery (tc);
991 /* Remove invalid blocks */
992 blk = tc->rcv_opts.sacks;
993 while (blk < vec_end (tc->rcv_opts.sacks))
995 if (seq_lt (blk->start, blk->end)
996 && seq_gt (blk->start, tc->snd_una)
997 && seq_gt (blk->start, ack)
998 && seq_lt (blk->start, tc->snd_nxt)
999 && seq_leq (blk->end, tc->snd_nxt))
1004 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
1007 /* Add block for cumulative ack */
1008 if (seq_gt (ack, tc->snd_una))
1010 vec_add2 (tc->rcv_opts.sacks, blk, 1);
1011 blk->start = tc->snd_una;
1015 if (vec_len (tc->rcv_opts.sacks) == 0)
1018 tcp_scoreboard_trace_add (tc, ack);
1020 /* Make sure blocks are ordered */
1021 rcv_sacks = tc->rcv_opts.sacks;
1022 for (i = 0; i < vec_len (rcv_sacks); i++)
1023 for (j = i + 1; j < vec_len (rcv_sacks); j++)
1024 if (seq_lt (rcv_sacks[j].start, rcv_sacks[i].start))
1026 sack_block_t tmp = rcv_sacks[i];
1027 rcv_sacks[i] = rcv_sacks[j];
1031 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
1033 /* Handle reneging as a special case */
1034 if (PREDICT_FALSE (sb->is_reneging))
1036 /* No holes, only sacked bytes */
1037 if (seq_leq (tc->snd_nxt, sb->high_sacked))
1039 /* No progress made so return */
1040 if (seq_leq (ack, tc->snd_una))
1043 /* Update sacked bytes delivered and return */
1044 sb->last_bytes_delivered = ack - tc->snd_una;
1045 sb->sacked_bytes -= sb->last_bytes_delivered;
1046 sb->is_reneging = seq_lt (ack, sb->high_sacked);
1050 /* New hole above high sacked. Add it and process normally */
1051 hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
1052 sb->high_sacked, tc->snd_nxt);
1053 sb->tail = scoreboard_hole_index (sb, hole);
1055 /* Not reneging and no holes. Insert the first that covers all
1056 * outstanding bytes */
1059 hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
1060 tc->snd_una, tc->snd_nxt);
1061 sb->tail = scoreboard_hole_index (sb, hole);
1063 sb->high_sacked = rcv_sacks[vec_len (rcv_sacks) - 1].end;
1067 /* If we have holes but snd_nxt is beyond the last hole, update
1068 * last hole end or add new hole after high sacked */
1069 hole = scoreboard_last_hole (sb);
1070 if (seq_gt (tc->snd_nxt, hole->end))
1072 if (seq_geq (hole->start, sb->high_sacked))
1074 hole->end = tc->snd_nxt;
1076 /* New hole after high sacked block */
1077 else if (seq_lt (sb->high_sacked, tc->snd_nxt))
1079 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
1084 /* Keep track of max byte sacked for when the last hole
1086 sb->high_sacked = seq_max (rcv_sacks[vec_len (rcv_sacks) - 1].end,
1090 /* Walk the holes with the SACK blocks */
1091 hole = pool_elt_at_index (sb->holes, sb->head);
1093 if (PREDICT_FALSE (sb->is_reneging))
1094 sb->last_bytes_delivered += hole->start - tc->snd_una;
1096 while (hole && blk_index < vec_len (rcv_sacks))
1098 blk = &rcv_sacks[blk_index];
1099 if (seq_leq (blk->start, hole->start))
1101 /* Block covers hole. Remove hole */
1102 if (seq_geq (blk->end, hole->end))
1104 next_hole = scoreboard_next_hole (sb, hole);
1106 /* If covered by ack, compute delivered bytes */
1107 if (blk->end == ack)
1109 u32 sacked = next_hole ? next_hole->start : sb->high_sacked;
1110 if (PREDICT_FALSE (seq_lt (ack, sacked)))
1112 sb->last_bytes_delivered += ack - hole->end;
1113 sb->is_reneging = 1;
1117 sb->last_bytes_delivered += sacked - hole->end;
1118 sb->is_reneging = 0;
1121 scoreboard_update_sacked_rxt (sb, hole->start, hole->end,
1123 scoreboard_remove_hole (sb, hole);
1126 /* Partial 'head' overlap */
1129 if (seq_gt (blk->end, hole->start))
1131 scoreboard_update_sacked_rxt (sb, hole->start, blk->end,
1133 hole->start = blk->end;
1140 /* Hole must be split */
1141 if (seq_lt (blk->end, hole->end))
1143 u32 hole_index = scoreboard_hole_index (sb, hole);
1144 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
1146 /* Pool might've moved */
1147 hole = scoreboard_get_hole (sb, hole_index);
1148 hole->end = blk->start;
1150 scoreboard_update_sacked_rxt (sb, blk->start, blk->end,
1154 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
1156 else if (seq_lt (blk->start, hole->end))
1158 scoreboard_update_sacked_rxt (sb, blk->start, hole->end,
1160 hole->end = blk->start;
1162 hole = scoreboard_next_hole (sb, hole);
1166 scoreboard_update_bytes (sb, ack, tc->snd_mss);
1168 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
1169 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
1170 || sb->sacked_bytes <= tc->snd_nxt - seq_max (tc->snd_una, ack));
1171 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_nxt
1172 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1173 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1174 || sb->is_reneging || sb->holes[sb->head].start == ack);
1175 ASSERT (sb->last_lost_bytes <= sb->lost_bytes);
1176 ASSERT ((ack - tc->snd_una) + sb->last_sacked_bytes
1177 - sb->last_bytes_delivered >= sb->rxt_sacked);
1178 ASSERT ((ack - tc->snd_una) >= tc->sack_sb.last_bytes_delivered
1179 || (tc->flags & TCP_CONN_FINSNT));
1181 TCP_EVT (TCP_EVT_CC_SCOREBOARD, tc);
1183 #endif /* CLIB_MARCH_VARIANT */
1186 * Try to update snd_wnd based on feedback received from peer.
1188 * If successful, and new window is 'effectively' 0, activate persist
1192 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1194 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1195 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1196 if (seq_lt (tc->snd_wl1, seq)
1197 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1199 tc->snd_wnd = snd_wnd;
1202 TCP_EVT (TCP_EVT_SND_WND, tc);
1204 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
1206 /* Set persist timer if not set and we just got 0 wnd */
1207 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1208 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1209 tcp_persist_timer_set (tc);
1213 tcp_persist_timer_reset (tc);
1214 if (PREDICT_FALSE (!tcp_in_recovery (tc) && tc->rto_boff > 0))
1217 tcp_update_rto (tc);
1224 * Init loss recovery/fast recovery.
1226 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1227 * updated in @ref tcp_cc_handle_event after fast retransmit
1230 tcp_cc_init_congestion (tcp_connection_t * tc)
1232 tcp_fastrecovery_on (tc);
1233 tc->snd_congestion = tc->snd_nxt;
1234 tc->cwnd_acc_bytes = 0;
1235 tc->snd_rxt_bytes = 0;
1236 tc->rxt_delivered = 0;
1237 tc->prr_delivered = 0;
1238 tc->prr_start = tc->snd_una;
1239 tc->prev_ssthresh = tc->ssthresh;
1240 tc->prev_cwnd = tc->cwnd;
1242 tc->snd_rxt_ts = tcp_tstamp (tc);
1243 tcp_cc_congestion (tc);
1245 /* Post retransmit update cwnd to ssthresh and account for the
1246 * three segments that have left the network and should've been
1247 * buffered at the receiver XXX */
1248 if (!tcp_opts_sack_permitted (&tc->rcv_opts))
1249 tc->cwnd += 3 * tc->snd_mss;
1251 tc->fr_occurences += 1;
1252 TCP_EVT (TCP_EVT_CC_EVT, tc, 4);
1256 tcp_cc_congestion_undo (tcp_connection_t * tc)
1258 tc->cwnd = tc->prev_cwnd;
1259 tc->ssthresh = tc->prev_ssthresh;
1260 tcp_cc_undo_recovery (tc);
1261 ASSERT (tc->rto_boff == 0);
1262 TCP_EVT (TCP_EVT_CC_EVT, tc, 5);
1266 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1268 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1270 && tcp_opts_tstamp (&tc->rcv_opts)
1271 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1275 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1277 return (tcp_cc_is_spurious_timeout_rxt (tc));
1281 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1283 return (tc->sack_sb.lost_bytes
1284 || ((TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
1285 < tc->sack_sb.sacked_bytes));
1289 tcp_should_fastrecover (tcp_connection_t * tc, u8 has_sack)
1293 /* If of of the two conditions lower hold, reset dupacks because
1294 * we're probably after timeout (RFC6582 heuristics).
1295 * If Cumulative ack does not cover more than congestion threshold,
1297 * 1) The following doesn't hold: The congestion window is greater
1298 * than SMSS bytes and the difference between highest_ack
1299 * and prev_highest_ack is at most 4*SMSS bytes
1300 * 2) Echoed timestamp in the last non-dup ack does not equal the
1303 if (seq_leq (tc->snd_una, tc->snd_congestion)
1304 && ((!(tc->cwnd > tc->snd_mss
1305 && tc->bytes_acked <= 4 * tc->snd_mss))
1306 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1308 tc->rcv_dupacks = 0;
1312 return ((tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1313 || tcp_should_fastrecover_sack (tc));
1317 tcp_cc_recover (tcp_connection_t * tc)
1319 sack_scoreboard_hole_t *hole;
1322 ASSERT (tcp_in_cong_recovery (tc));
1324 if (tcp_cc_is_spurious_retransmit (tc))
1326 tcp_cc_congestion_undo (tc);
1330 tc->rcv_dupacks = 0;
1331 tc->prr_delivered = 0;
1332 tc->rxt_delivered = 0;
1333 tc->snd_rxt_bytes = 0;
1336 tc->flags &= ~TCP_CONN_RXT_PENDING;
1338 /* Previous recovery left us congested. Continue sending as part
1339 * of the current recovery event with an updated snd_congestion */
1340 if (tc->sack_sb.sacked_bytes)
1342 tc->snd_congestion = tc->snd_nxt;
1343 tc->snd_rxt_ts = tcp_tstamp (tc);
1344 tc->prr_start = tc->snd_una;
1345 scoreboard_init_rxt (&tc->sack_sb, tc->snd_una);
1346 tcp_program_retransmit (tc);
1350 hole = scoreboard_first_hole (&tc->sack_sb);
1351 if (hole && hole->start == tc->snd_una && hole->end == tc->snd_nxt)
1352 scoreboard_clear (&tc->sack_sb);
1354 if (!tcp_in_recovery (tc) && !is_spurious)
1355 tcp_cc_recovered (tc);
1357 tcp_connection_tx_pacer_reset (tc, tc->cwnd, 0 /* start bucket */ );
1359 tcp_fastrecovery_off (tc);
1360 tcp_fastrecovery_first_off (tc);
1361 tcp_recovery_off (tc);
1362 TCP_EVT (TCP_EVT_CC_EVT, tc, 3);
1364 ASSERT (tc->rto_boff == 0);
1365 ASSERT (!tcp_in_cong_recovery (tc));
1366 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1371 tcp_cc_update (tcp_connection_t * tc, tcp_rate_sample_t * rs)
1373 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1375 /* Congestion avoidance */
1376 tcp_cc_rcv_ack (tc, rs);
1378 /* If a cumulative ack, make sure dupacks is 0 */
1379 tc->rcv_dupacks = 0;
1381 /* When dupacks hits the threshold we only enter fast retransmit if
1382 * cumulative ack covers more than snd_congestion. Should snd_una
1383 * wrap this test may fail under otherwise valid circumstances.
1384 * Therefore, proactively update snd_congestion when wrap detected. */
1386 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1387 && seq_gt (tc->snd_congestion, tc->snd_una)))
1388 tc->snd_congestion = tc->snd_una - 1;
1392 * One function to rule them all ... and in the darkness bind them
1395 tcp_cc_handle_event (tcp_connection_t * tc, tcp_rate_sample_t * rs,
1398 u8 has_sack = tcp_opts_sack_permitted (&tc->rcv_opts);
1401 * If not in recovery, figure out if we should enter
1403 if (!tcp_in_cong_recovery (tc))
1408 TCP_EVT (TCP_EVT_DUPACK_RCVD, tc, 1);
1409 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1411 if (tcp_should_fastrecover (tc, has_sack))
1413 tcp_cc_init_congestion (tc);
1416 scoreboard_init_rxt (&tc->sack_sb, tc->snd_una);
1418 tcp_connection_tx_pacer_reset (tc, tc->cwnd, 0 /* start bucket */ );
1419 tcp_program_retransmit (tc);
1426 * Already in recovery. See if we can exit and stop retransmitting
1429 if (seq_geq (tc->snd_una, tc->snd_congestion))
1431 /* If spurious return, we've already updated everything */
1432 if (tcp_cc_recover (tc))
1434 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1438 /* Treat as congestion avoidance ack */
1439 tcp_cc_rcv_ack (tc, rs);
1444 * Process (re)transmit feedback. Output path uses this to decide how much
1445 * more data to release into the network
1449 tc->rxt_delivered += tc->sack_sb.rxt_sacked;
1450 tc->prr_delivered += tc->bytes_acked + tc->sack_sb.last_sacked_bytes
1451 - tc->sack_sb.last_bytes_delivered;
1453 tcp_program_retransmit (tc);
1459 tc->rcv_dupacks += 1;
1460 TCP_EVT (TCP_EVT_DUPACK_RCVD, tc, 1);
1462 tc->rxt_delivered = clib_max (tc->rxt_delivered + tc->bytes_acked,
1465 tc->prr_delivered += 1;
1467 tc->prr_delivered += tc->bytes_acked - tc->snd_mss * tc->rcv_dupacks;
1469 /* If partial ack, assume that the first un-acked segment was lost */
1470 if (tc->bytes_acked || tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1471 tcp_fastrecovery_first_on (tc);
1473 tcp_program_retransmit (tc);
1477 * Notify cc of the event
1480 if (!tc->bytes_acked)
1482 tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs);
1486 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1487 * reset dupacks to 0. Also needed if in congestion recovery */
1488 tc->rcv_dupacks = 0;
1490 if (tcp_in_recovery (tc))
1491 tcp_cc_rcv_ack (tc, rs);
1493 tcp_cc_rcv_cong_ack (tc, TCP_CC_PARTIALACK, rs);
1497 * Check if duplicate ack as per RFC5681 Sec. 2
1500 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
1503 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
1504 && seq_gt (tc->snd_nxt, tc->snd_una)
1505 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
1506 && (prev_snd_wnd == tc->snd_wnd));
1510 * Checks if ack is a congestion control event.
1513 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
1514 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
1516 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
1517 * defined to be 'duplicate' as well */
1518 *is_dack = tc->sack_sb.last_sacked_bytes
1519 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
1521 /* If reneging, wait for timer based retransmits */
1522 if (PREDICT_FALSE (tcp_is_lost_fin (tc) || tc->sack_sb.is_reneging))
1525 return (*is_dack || tcp_in_cong_recovery (tc));
1529 * Process incoming ACK
1532 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1533 tcp_header_t * th, u32 * error)
1535 u32 prev_snd_wnd, prev_snd_una;
1536 tcp_rate_sample_t rs = { 0 };
1539 TCP_EVT (TCP_EVT_CC_STAT, tc);
1541 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1542 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1544 /* We've probably entered recovery and the peer still has some
1545 * of the data we've sent. Update snd_nxt and accept the ack */
1546 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)
1547 && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
1549 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1553 tc->errors.above_ack_wnd += 1;
1554 *error = TCP_ERROR_ACK_FUTURE;
1555 TCP_EVT (TCP_EVT_ACK_RCV_ERR, tc, 0, vnet_buffer (b)->tcp.ack_number);
1559 /* If old ACK, probably it's an old dupack */
1560 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1562 tc->errors.below_ack_wnd += 1;
1563 *error = TCP_ERROR_ACK_OLD;
1564 TCP_EVT (TCP_EVT_ACK_RCV_ERR, tc, 1, vnet_buffer (b)->tcp.ack_number);
1565 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1566 tcp_cc_handle_event (tc, 0, 1);
1567 /* Don't drop yet */
1574 * Looks okay, process feedback
1577 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1578 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1580 prev_snd_wnd = tc->snd_wnd;
1581 prev_snd_una = tc->snd_una;
1582 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1583 vnet_buffer (b)->tcp.ack_number,
1584 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1585 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1586 tc->snd_una = vnet_buffer (b)->tcp.ack_number;
1587 tcp_validate_txf_size (tc, tc->bytes_acked);
1589 if (tc->flags & TCP_CONN_RATE_SAMPLE)
1590 tcp_bt_sample_delivery_rate (tc, &rs);
1592 if (tc->bytes_acked)
1594 tcp_program_dequeue (wrk, tc);
1595 tcp_update_rtt (tc, &rs, vnet_buffer (b)->tcp.ack_number);
1598 TCP_EVT (TCP_EVT_ACK_RCVD, tc);
1601 * Check if we have congestion event
1604 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1606 tcp_cc_handle_event (tc, &rs, is_dack);
1607 tc->dupacks_in += is_dack;
1608 if (!tcp_in_cong_recovery (tc))
1610 *error = TCP_ERROR_ACK_OK;
1613 *error = TCP_ERROR_ACK_DUP;
1614 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1620 * Update congestion control (slow start/congestion avoidance)
1622 tcp_cc_update (tc, &rs);
1623 *error = TCP_ERROR_ACK_OK;
1628 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1630 if (!tcp_disconnect_pending (tc))
1632 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1633 tcp_disconnect_pending_on (tc);
1638 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1640 u32 thread_index, *pending_disconnects;
1641 tcp_connection_t *tc;
1644 if (!vec_len (wrk->pending_disconnects))
1647 thread_index = wrk->vm->thread_index;
1648 pending_disconnects = wrk->pending_disconnects;
1649 for (i = 0; i < vec_len (pending_disconnects); i++)
1651 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1652 tcp_disconnect_pending_off (tc);
1653 session_transport_closing_notify (&tc->connection);
1655 _vec_len (wrk->pending_disconnects) = 0;
1659 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1662 /* Reject out-of-order fins */
1663 if (vnet_buffer (b)->tcp.seq_end != tc->rcv_nxt)
1666 /* Account for the FIN and send ack */
1668 tcp_program_ack (tc);
1669 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1670 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1671 tcp_connection_set_state (tc, TCP_STATE_CLOSE_WAIT);
1672 tcp_program_disconnect (wrk, tc);
1673 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
1674 TCP_EVT (TCP_EVT_FIN_RCVD, tc);
1675 *error = TCP_ERROR_FIN_RCVD;
1678 #ifndef CLIB_MARCH_VARIANT
1680 tcp_sack_vector_is_sane (sack_block_t * sacks)
1683 for (i = 1; i < vec_len (sacks); i++)
1685 if (sacks[i - 1].end == sacks[i].start)
1692 * Build SACK list as per RFC2018.
1694 * Makes sure the first block contains the segment that generated the current
1695 * ACK and the following ones are the ones most recently reported in SACK
1698 * @param tc TCP connection for which the SACK list is updated
1699 * @param start Start sequence number of the newest SACK block
1700 * @param end End sequence of the newest SACK block
1703 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1705 sack_block_t *new_list = tc->snd_sacks_fl, *block = 0;
1708 /* If the first segment is ooo add it to the list. Last write might've moved
1709 * rcv_nxt over the first segment. */
1710 if (seq_lt (tc->rcv_nxt, start))
1712 vec_add2 (new_list, block, 1);
1713 block->start = start;
1717 /* Find the blocks still worth keeping. */
1718 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1720 /* Discard if rcv_nxt advanced beyond current block */
1721 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1724 /* Merge or drop if segment overlapped by the new segment */
1725 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1726 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1728 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1729 new_list[0].start = tc->snd_sacks[i].start;
1730 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1731 new_list[0].end = tc->snd_sacks[i].end;
1735 /* Save to new SACK list if we have space. */
1736 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1737 vec_add1 (new_list, tc->snd_sacks[i]);
1740 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1742 /* Replace old vector with new one */
1743 vec_reset_length (tc->snd_sacks);
1744 tc->snd_sacks_fl = tc->snd_sacks;
1745 tc->snd_sacks = new_list;
1747 /* Segments should not 'touch' */
1748 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1752 tcp_sack_list_bytes (tcp_connection_t * tc)
1755 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1756 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1759 #endif /* CLIB_MARCH_VARIANT */
1761 /** Enqueue data for delivery to application */
1763 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1766 int written, error = TCP_ERROR_ENQUEUED;
1768 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1770 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1771 1 /* queue event */ , 1);
1772 tc->bytes_in += written;
1774 TCP_EVT (TCP_EVT_INPUT, tc, 0, data_len, written);
1776 /* Update rcv_nxt */
1777 if (PREDICT_TRUE (written == data_len))
1779 tc->rcv_nxt += written;
1781 /* If more data written than expected, account for out-of-order bytes. */
1782 else if (written > data_len)
1784 tc->rcv_nxt += written;
1785 TCP_EVT (TCP_EVT_CC_INPUT, tc, data_len, written);
1787 else if (written > 0)
1789 /* We've written something but FIFO is probably full now */
1790 tc->rcv_nxt += written;
1791 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1795 return TCP_ERROR_FIFO_FULL;
1798 /* Update SACK list if need be */
1799 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1801 /* Remove SACK blocks that have been delivered */
1802 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1808 /** Enqueue out-of-order data */
1810 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1816 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1819 /* Enqueue out-of-order data with relative offset */
1820 rv = session_enqueue_stream_connection (&tc->connection, b,
1821 vnet_buffer (b)->tcp.seq_number -
1822 tc->rcv_nxt, 0 /* queue event */ ,
1825 /* Nothing written */
1828 TCP_EVT (TCP_EVT_INPUT, tc, 1, data_len, 0);
1829 return TCP_ERROR_FIFO_FULL;
1832 TCP_EVT (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1833 tc->bytes_in += data_len;
1835 /* Update SACK list if in use */
1836 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1838 ooo_segment_t *newest;
1841 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1843 /* Get the newest segment from the fifo */
1844 newest = svm_fifo_newest_ooo_segment (s0->rx_fifo);
1847 offset = ooo_segment_offset_prod (s0->rx_fifo, newest);
1848 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1849 start = tc->rcv_nxt + offset;
1850 end = start + ooo_segment_length (s0->rx_fifo, newest);
1851 tcp_update_sack_list (tc, start, end);
1852 svm_fifo_newest_ooo_segment_reset (s0->rx_fifo);
1853 TCP_EVT (TCP_EVT_CC_SACKS, tc);
1857 return TCP_ERROR_ENQUEUED_OOO;
1861 * Check if ACK could be delayed. If ack can be delayed, it should return
1862 * true for a full frame. If we're always acking return 0.
1865 tcp_can_delack (tcp_connection_t * tc)
1867 /* Send ack if ... */
1869 /* just sent a rcv wnd 0
1870 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0 */
1871 /* constrained to send ack */
1872 || (tc->flags & TCP_CONN_SNDACK) != 0
1873 /* we're almost out of tx wnd */
1874 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1881 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1883 u32 discard, first = b->current_length;
1884 vlib_main_t *vm = vlib_get_main ();
1886 /* Handle multi-buffer segments */
1887 if (n_bytes_to_drop > b->current_length)
1889 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1893 discard = clib_min (n_bytes_to_drop, b->current_length);
1894 vlib_buffer_advance (b, discard);
1895 b = vlib_get_buffer (vm, b->next_buffer);
1896 n_bytes_to_drop -= discard;
1898 while (n_bytes_to_drop);
1899 if (n_bytes_to_drop > first)
1900 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1903 vlib_buffer_advance (b, n_bytes_to_drop);
1904 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1909 * Receive buffer for connection and handle acks
1911 * It handles both in order or out-of-order data.
1914 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1917 u32 error, n_bytes_to_drop, n_data_bytes;
1919 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1920 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1921 ASSERT (n_data_bytes);
1922 tc->data_segs_in += 1;
1924 /* Handle out-of-order data */
1925 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1927 /* Old sequence numbers allowed through because they overlapped
1929 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1931 /* Completely in the past (possible retransmit). Ack
1932 * retransmissions since we may not have any data to send */
1933 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1935 tcp_program_ack (tc);
1936 error = TCP_ERROR_SEGMENT_OLD;
1940 /* Chop off the bytes in the past and see if what is left
1941 * can be enqueued in order */
1942 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1943 n_data_bytes -= n_bytes_to_drop;
1944 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1945 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1947 error = TCP_ERROR_SEGMENT_OLD;
1953 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1954 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1955 tcp_program_dupack (tc);
1956 TCP_EVT (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1957 tc->errors.above_data_wnd += seq_gt (vnet_buffer (b)->tcp.seq_end,
1958 tc->rcv_las + tc->rcv_wnd);
1964 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1965 * segments can be enqueued after fifo tail offset changes. */
1966 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1967 if (tcp_can_delack (tc))
1969 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1970 tcp_timer_set (tc, TCP_TIMER_DELACK, tcp_cfg.delack_time);
1974 tcp_program_ack (tc);
1982 tcp_header_t tcp_header;
1983 tcp_connection_t tcp_connection;
1987 format_tcp_rx_trace (u8 * s, va_list * args)
1989 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1990 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1991 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1992 u32 indent = format_get_indent (s);
1994 s = format (s, "%U\n%U%U",
1995 format_tcp_header, &t->tcp_header, 128,
1996 format_white_space, indent,
1997 format_tcp_connection, &t->tcp_connection, 1);
2003 format_tcp_rx_trace_short (u8 * s, va_list * args)
2005 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2006 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2007 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2009 s = format (s, "%d -> %d (%U)",
2010 clib_net_to_host_u16 (t->tcp_header.dst_port),
2011 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
2012 t->tcp_connection.state);
2018 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
2019 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
2023 clib_memcpy_fast (&t0->tcp_connection, tc0,
2024 sizeof (t0->tcp_connection));
2028 th0 = tcp_buffer_hdr (b0);
2030 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2034 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2035 vlib_frame_t * frame, u8 is_ip4)
2039 n_left = frame->n_vectors;
2040 from = vlib_frame_vector_args (frame);
2044 tcp_connection_t *tc0;
2051 b0 = vlib_get_buffer (vm, bi0);
2053 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2055 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2056 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2058 th0 = tcp_buffer_hdr (b0);
2059 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2068 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2069 u8 is_ip4, u32 evt, u32 val)
2072 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2074 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2077 #define tcp_maybe_inc_counter(node_id, err, count) \
2079 if (next0 != tcp_next_drop (is_ip4)) \
2080 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2081 tcp6_##node_id##_node.index, is_ip4, err, \
2084 #define tcp_inc_counter(node_id, err, count) \
2085 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2086 tcp6_##node_id##_node.index, is_ip4, \
2088 #define tcp_maybe_inc_err_counter(cnts, err) \
2090 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2092 #define tcp_inc_err_counter(cnts, err, val) \
2096 #define tcp_store_err_counters(node_id, cnts) \
2099 for (i = 0; i < TCP_N_ERROR; i++) \
2101 tcp_inc_counter(node_id, i, cnts[i]); \
2106 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2107 vlib_frame_t * frame, int is_ip4)
2109 u32 thread_index = vm->thread_index, errors = 0;
2110 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2111 u32 n_left_from, *from, *first_buffer;
2112 u16 err_counters[TCP_N_ERROR] = { 0 };
2114 if (node->flags & VLIB_NODE_FLAG_TRACE)
2115 tcp_established_trace_frame (vm, node, frame, is_ip4);
2117 first_buffer = from = vlib_frame_vector_args (frame);
2118 n_left_from = frame->n_vectors;
2120 while (n_left_from > 0)
2122 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2125 tcp_connection_t *tc0;
2127 if (n_left_from > 1)
2130 pb = vlib_get_buffer (vm, from[1]);
2131 vlib_prefetch_buffer_header (pb, LOAD);
2132 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2139 b0 = vlib_get_buffer (vm, bi0);
2140 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2143 if (PREDICT_FALSE (tc0 == 0))
2145 error0 = TCP_ERROR_INVALID_CONNECTION;
2149 th0 = tcp_buffer_hdr (b0);
2151 /* TODO header prediction fast path */
2153 /* 1-4: check SEQ, RST, SYN */
2154 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2156 TCP_EVT (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2160 /* 5: check the ACK field */
2161 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2164 /* 6: check the URG bit TODO */
2166 /* 7: process the segment text */
2167 if (vnet_buffer (b0)->tcp.data_len)
2168 error0 = tcp_segment_rcv (wrk, tc0, b0);
2170 /* 8: check the FIN bit */
2171 if (PREDICT_FALSE (tcp_is_fin (th0)))
2172 tcp_rcv_fin (wrk, tc0, b0, &error0);
2175 tcp_inc_err_counter (err_counters, error0, 1);
2178 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2180 err_counters[TCP_ERROR_MSG_QUEUE_FULL] = errors;
2181 tcp_store_err_counters (established, err_counters);
2182 tcp_handle_postponed_dequeues (wrk);
2183 tcp_handle_disconnects (wrk);
2184 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2186 return frame->n_vectors;
2189 VLIB_NODE_FN (tcp4_established_node) (vlib_main_t * vm,
2190 vlib_node_runtime_t * node,
2191 vlib_frame_t * from_frame)
2193 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2196 VLIB_NODE_FN (tcp6_established_node) (vlib_main_t * vm,
2197 vlib_node_runtime_t * node,
2198 vlib_frame_t * from_frame)
2200 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2204 VLIB_REGISTER_NODE (tcp4_established_node) =
2206 .name = "tcp4-established",
2207 /* Takes a vector of packets. */
2208 .vector_size = sizeof (u32),
2209 .n_errors = TCP_N_ERROR,
2210 .error_strings = tcp_error_strings,
2211 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2214 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2215 foreach_tcp_state_next
2218 .format_trace = format_tcp_rx_trace_short,
2223 VLIB_REGISTER_NODE (tcp6_established_node) =
2225 .name = "tcp6-established",
2226 /* Takes a vector of packets. */
2227 .vector_size = sizeof (u32),
2228 .n_errors = TCP_N_ERROR,
2229 .error_strings = tcp_error_strings,
2230 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2233 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2234 foreach_tcp_state_next
2237 .format_trace = format_tcp_rx_trace_short,
2243 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2245 transport_connection_t *tmp = 0;
2252 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2255 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2256 && (tc->state == TCP_STATE_LISTEN
2257 || tc->c_rmt_port == hdr->src_port));
2261 handle = session_lookup_half_open_handle (&tc->connection);
2262 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2263 tc->c_proto, tc->c_is_ip4);
2267 if (tmp->lcl_port == hdr->dst_port
2268 && tmp->rmt_port == hdr->src_port)
2270 TCP_DBG ("half-open is valid!");
2278 * Lookup transport connection
2280 static tcp_connection_t *
2281 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2285 transport_connection_t *tconn;
2286 tcp_connection_t *tc;
2291 ip4 = vlib_buffer_get_current (b);
2292 tcp = ip4_next_header (ip4);
2293 tconn = session_lookup_connection_wt4 (fib_index,
2298 TRANSPORT_PROTO_TCP,
2299 thread_index, &is_filtered);
2300 tc = tcp_get_connection_from_transport (tconn);
2301 ASSERT (tcp_lookup_is_valid (tc, tcp));
2306 ip6 = vlib_buffer_get_current (b);
2307 tcp = ip6_next_header (ip6);
2308 tconn = session_lookup_connection_wt6 (fib_index,
2313 TRANSPORT_PROTO_TCP,
2314 thread_index, &is_filtered);
2315 tc = tcp_get_connection_from_transport (tconn);
2316 ASSERT (tcp_lookup_is_valid (tc, tcp));
2322 tcp_check_tx_offload (tcp_connection_t * tc, int is_ipv4)
2324 vnet_main_t *vnm = vnet_get_main ();
2325 const dpo_id_t *dpo;
2326 const load_balance_t *lb;
2327 vnet_hw_interface_t *hw_if;
2328 u32 sw_if_idx, lb_idx;
2332 ip4_address_t *dst_addr = &(tc->c_rmt_ip.ip4);
2333 lb_idx = ip4_fib_forwarding_lookup (tc->c_fib_index, dst_addr);
2337 ip6_address_t *dst_addr = &(tc->c_rmt_ip.ip6);
2338 lb_idx = ip6_fib_table_fwding_lookup (tc->c_fib_index, dst_addr);
2341 lb = load_balance_get (lb_idx);
2342 dpo = load_balance_get_bucket_i (lb, 0);
2344 sw_if_idx = dpo->dpoi_index;
2345 hw_if = vnet_get_sup_hw_interface (vnm, sw_if_idx);
2348 ((hw_if->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO) == 0) ? 0 : 1;
2353 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2354 vlib_frame_t * from_frame, int is_ip4)
2356 u32 n_left_from, *from, *first_buffer, errors = 0;
2357 u32 my_thread_index = vm->thread_index;
2358 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2360 from = first_buffer = vlib_frame_vector_args (from_frame);
2361 n_left_from = from_frame->n_vectors;
2363 while (n_left_from > 0)
2365 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2366 tcp_connection_t *tc0, *new_tc0;
2367 tcp_header_t *tcp0 = 0;
2375 b0 = vlib_get_buffer (vm, bi0);
2377 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2378 if (PREDICT_FALSE (tc0 == 0))
2380 error0 = TCP_ERROR_INVALID_CONNECTION;
2384 /* Half-open completed recently but the connection was't removed
2385 * yet by the owning thread */
2386 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2388 /* Make sure the connection actually exists */
2389 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2390 my_thread_index, is_ip4));
2391 error0 = TCP_ERROR_SPURIOUS_SYN_ACK;
2395 ack0 = vnet_buffer (b0)->tcp.ack_number;
2396 seq0 = vnet_buffer (b0)->tcp.seq_number;
2397 tcp0 = tcp_buffer_hdr (b0);
2399 /* Crude check to see if the connection handle does not match
2400 * the packet. Probably connection just switched to established */
2401 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2402 || tcp0->src_port != tc0->c_rmt_port))
2404 error0 = TCP_ERROR_INVALID_CONNECTION;
2408 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2409 && !tcp_syn (tcp0)))
2411 error0 = TCP_ERROR_SEGMENT_INVALID;
2415 /* SYNs consume sequence numbers */
2416 vnet_buffer (b0)->tcp.seq_end += tcp_is_syn (tcp0);
2419 * 1. check the ACK bit
2423 * If the ACK bit is set
2424 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2425 * the RST bit is set, if so drop the segment and return)
2426 * <SEQ=SEG.ACK><CTL=RST>
2427 * and discard the segment. Return.
2428 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2432 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2434 if (!tcp_rst (tcp0))
2435 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2436 error0 = TCP_ERROR_RCV_WND;
2440 /* Make sure ACK is valid */
2441 if (seq_gt (tc0->snd_una, ack0))
2443 error0 = TCP_ERROR_ACK_INVALID;
2449 * 2. check the RST bit
2454 /* If ACK is acceptable, signal client that peer is not
2455 * willing to accept connection and drop connection*/
2457 tcp_connection_reset (tc0);
2458 error0 = TCP_ERROR_RST_RCVD;
2463 * 3. check the security and precedence (skipped)
2467 * 4. check the SYN bit
2470 /* No SYN flag. Drop. */
2471 if (!tcp_syn (tcp0))
2473 error0 = TCP_ERROR_SEGMENT_INVALID;
2478 if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1))
2480 error0 = TCP_ERROR_OPTIONS;
2484 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2485 * current thread pool. */
2486 new_tc0 = tcp_connection_alloc_w_base (my_thread_index, tc0);
2487 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2488 new_tc0->irs = seq0;
2489 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2490 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2492 /* If this is not the owning thread, wait for syn retransmit to
2493 * expire and cleanup then */
2494 if (tcp_half_open_connection_cleanup (tc0))
2495 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2497 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2499 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2500 new_tc0->tsval_recent_age = tcp_time_now ();
2503 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2504 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2506 new_tc0->rcv_wscale = 0;
2508 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2509 << new_tc0->snd_wscale;
2510 new_tc0->snd_wl1 = seq0;
2511 new_tc0->snd_wl2 = ack0;
2513 tcp_connection_init_vars (new_tc0);
2515 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2516 if (PREDICT_TRUE (tcp_ack (tcp0)))
2518 /* Our SYN is ACKed: we have iss < ack = snd_una */
2520 /* TODO Dequeue acknowledged segments if we support Fast Open */
2521 new_tc0->snd_una = ack0;
2522 new_tc0->state = TCP_STATE_ESTABLISHED;
2524 /* Make sure las is initialized for the wnd computation */
2525 new_tc0->rcv_las = new_tc0->rcv_nxt;
2527 /* Notify app that we have connection. If session layer can't
2528 * allocate session send reset */
2529 if (session_stream_connect_notify (&new_tc0->connection, 0))
2531 tcp_send_reset_w_pkt (new_tc0, b0, my_thread_index, is_ip4);
2532 tcp_connection_cleanup (new_tc0);
2533 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2537 new_tc0->tx_fifo_size =
2538 transport_tx_fifo_size (&new_tc0->connection);
2539 /* Update rtt with the syn-ack sample */
2540 tcp_estimate_initial_rtt (new_tc0);
2541 TCP_EVT (TCP_EVT_SYNACK_RCVD, new_tc0);
2542 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2544 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2547 new_tc0->state = TCP_STATE_SYN_RCVD;
2549 /* Notify app that we have connection */
2550 if (session_stream_connect_notify (&new_tc0->connection, 0))
2552 tcp_connection_cleanup (new_tc0);
2553 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2554 TCP_EVT (TCP_EVT_RST_SENT, tc0);
2555 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2559 new_tc0->tx_fifo_size =
2560 transport_tx_fifo_size (&new_tc0->connection);
2561 new_tc0->rtt_ts = 0;
2562 tcp_init_snd_vars (new_tc0);
2563 tcp_send_synack (new_tc0);
2564 error0 = TCP_ERROR_SYNS_RCVD;
2568 tcp_check_tx_offload (new_tc0, is_ip4);
2570 /* Read data, if any */
2571 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2573 clib_warning ("rcvd data in syn-sent");
2574 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2575 if (error0 == TCP_ERROR_ACK_OK)
2576 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2580 tcp_program_ack (new_tc0);
2585 tcp_inc_counter (syn_sent, error0, 1);
2586 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2588 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2589 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2590 clib_memcpy_fast (&t0->tcp_connection, tc0,
2591 sizeof (t0->tcp_connection));
2595 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2597 tcp_inc_counter (syn_sent, TCP_ERROR_MSG_QUEUE_FULL, errors);
2598 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2600 return from_frame->n_vectors;
2603 VLIB_NODE_FN (tcp4_syn_sent_node) (vlib_main_t * vm,
2604 vlib_node_runtime_t * node,
2605 vlib_frame_t * from_frame)
2607 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2610 VLIB_NODE_FN (tcp6_syn_sent_node) (vlib_main_t * vm,
2611 vlib_node_runtime_t * node,
2612 vlib_frame_t * from_frame)
2614 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2618 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2620 .name = "tcp4-syn-sent",
2621 /* Takes a vector of packets. */
2622 .vector_size = sizeof (u32),
2623 .n_errors = TCP_N_ERROR,
2624 .error_strings = tcp_error_strings,
2625 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2628 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2629 foreach_tcp_state_next
2632 .format_trace = format_tcp_rx_trace_short,
2637 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2639 .name = "tcp6-syn-sent",
2640 /* Takes a vector of packets. */
2641 .vector_size = sizeof (u32),
2642 .n_errors = TCP_N_ERROR,
2643 .error_strings = tcp_error_strings,
2644 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2647 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2648 foreach_tcp_state_next
2651 .format_trace = format_tcp_rx_trace_short,
2656 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2657 * as per RFC793 p. 64
2660 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2661 vlib_frame_t * from_frame, int is_ip4)
2663 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2664 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2665 u32 n_left_from, *from, max_dequeue;
2667 from = first_buffer = vlib_frame_vector_args (from_frame);
2668 n_left_from = from_frame->n_vectors;
2670 while (n_left_from > 0)
2672 u32 bi0, error0 = TCP_ERROR_NONE;
2673 tcp_header_t *tcp0 = 0;
2674 tcp_connection_t *tc0;
2682 b0 = vlib_get_buffer (vm, bi0);
2683 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2685 if (PREDICT_FALSE (tc0 == 0))
2687 error0 = TCP_ERROR_INVALID_CONNECTION;
2691 tcp0 = tcp_buffer_hdr (b0);
2692 is_fin0 = tcp_is_fin (tcp0);
2696 tcp_connection_t *tmp;
2697 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2699 if (tmp->state != tc0->state)
2701 if (tc0->state != TCP_STATE_CLOSED)
2702 clib_warning ("state changed");
2708 * Special treatment for CLOSED
2710 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2712 error0 = TCP_ERROR_CONNECTION_CLOSED;
2717 * For all other states (except LISTEN)
2720 /* 1-4: check SEQ, RST, SYN */
2721 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2724 /* 5: check the ACK field */
2727 case TCP_STATE_SYN_RCVD:
2729 /* Make sure the segment is exactly right */
2730 if (tc0->rcv_nxt != vnet_buffer (b0)->tcp.seq_number || is_fin0)
2732 tcp_connection_reset (tc0);
2733 error0 = TCP_ERROR_SEGMENT_INVALID;
2738 * If the segment acknowledgment is not acceptable, form a
2740 * <SEQ=SEG.ACK><CTL=RST>
2743 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2745 tcp_connection_reset (tc0);
2749 /* Update rtt and rto */
2750 tcp_estimate_initial_rtt (tc0);
2751 tcp_connection_tx_pacer_update (tc0);
2753 /* Switch state to ESTABLISHED */
2754 tc0->state = TCP_STATE_ESTABLISHED;
2755 TCP_EVT (TCP_EVT_STATE_CHANGE, tc0);
2757 tcp_check_tx_offload (tc0, is_ip4);
2759 /* Initialize session variables */
2760 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2761 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2762 << tc0->rcv_opts.wscale;
2763 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2764 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2766 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2767 tcp_retransmit_timer_reset (tc0);
2768 if (session_stream_accept_notify (&tc0->connection))
2770 error0 = TCP_ERROR_MSG_QUEUE_FULL;
2771 tcp_connection_reset (tc0);
2774 error0 = TCP_ERROR_ACK_OK;
2776 case TCP_STATE_ESTABLISHED:
2777 /* We can get packets in established state here because they
2778 * were enqueued before state change */
2779 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2783 case TCP_STATE_FIN_WAIT_1:
2784 /* In addition to the processing for the ESTABLISHED state, if
2785 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2786 * continue processing in that state. */
2787 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2790 /* Still have to send the FIN */
2791 if (tc0->flags & TCP_CONN_FINPNDG)
2793 /* TX fifo finally drained */
2794 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2795 if (max_dequeue <= tc0->burst_acked)
2797 /* If a fin was received and data was acked extend wait */
2798 else if ((tc0->flags & TCP_CONN_FINRCVD) && tc0->bytes_acked)
2799 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2800 tcp_cfg.closewait_time);
2802 /* If FIN is ACKed */
2803 else if (tc0->snd_una == tc0->snd_nxt)
2805 /* Stop all retransmit timers because we have nothing more
2807 tcp_connection_timers_reset (tc0);
2809 /* We already have a FIN but didn't transition to CLOSING
2810 * because of outstanding tx data. Close the connection. */
2811 if (tc0->flags & TCP_CONN_FINRCVD)
2813 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2814 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE,
2815 tcp_cfg.cleanup_time);
2816 session_transport_closed_notify (&tc0->connection);
2820 tcp_connection_set_state (tc0, TCP_STATE_FIN_WAIT_2);
2821 /* Enable waitclose because we're willing to wait for peer's
2822 * FIN but not indefinitely. */
2823 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.finwait2_time);
2825 /* Don't try to deq the FIN acked */
2826 if (tc0->burst_acked > 1)
2827 session_tx_fifo_dequeue_drop (&tc0->connection,
2828 tc0->burst_acked - 1);
2829 tc0->burst_acked = 0;
2832 case TCP_STATE_FIN_WAIT_2:
2833 /* In addition to the processing for the ESTABLISHED state, if
2834 * the retransmission queue is empty, the user's CLOSE can be
2835 * acknowledged ("ok") but do not delete the TCB. */
2836 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2838 tc0->burst_acked = 0;
2840 case TCP_STATE_CLOSE_WAIT:
2841 /* Do the same processing as for the ESTABLISHED state. */
2842 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2845 if (!(tc0->flags & TCP_CONN_FINPNDG))
2848 /* Still have outstanding tx data */
2849 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2850 if (max_dequeue > tc0->burst_acked)
2854 tcp_connection_timers_reset (tc0);
2855 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2856 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
2858 case TCP_STATE_CLOSING:
2859 /* In addition to the processing for the ESTABLISHED state, if
2860 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2861 * otherwise ignore the segment. */
2862 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2865 if (tc0->snd_una != tc0->snd_nxt)
2868 tcp_connection_timers_reset (tc0);
2869 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2870 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
2871 session_transport_closed_notify (&tc0->connection);
2875 case TCP_STATE_LAST_ACK:
2876 /* The only thing that [should] arrive in this state is an
2877 * acknowledgment of our FIN. If our FIN is now acknowledged,
2878 * delete the TCB, enter the CLOSED state, and return. */
2880 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2883 /* Apparently our ACK for the peer's FIN was lost */
2884 if (is_fin0 && tc0->snd_una != tc0->snd_nxt)
2890 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2891 session_transport_closed_notify (&tc0->connection);
2893 /* Don't free the connection from the data path since
2894 * we can't ensure that we have no packets already enqueued
2895 * to output. Rely instead on the waitclose timer */
2896 tcp_connection_timers_reset (tc0);
2897 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.cleanup_time);
2902 case TCP_STATE_TIME_WAIT:
2903 /* The only thing that can arrive in this state is a
2904 * retransmission of the remote FIN. Acknowledge it, and restart
2905 * the 2 MSL timeout. */
2907 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2913 tcp_program_ack (tc0);
2914 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
2922 /* 6: check the URG bit TODO */
2924 /* 7: process the segment text */
2927 case TCP_STATE_ESTABLISHED:
2928 case TCP_STATE_FIN_WAIT_1:
2929 case TCP_STATE_FIN_WAIT_2:
2930 if (vnet_buffer (b0)->tcp.data_len)
2931 error0 = tcp_segment_rcv (wrk, tc0, b0);
2933 case TCP_STATE_CLOSE_WAIT:
2934 case TCP_STATE_CLOSING:
2935 case TCP_STATE_LAST_ACK:
2936 case TCP_STATE_TIME_WAIT:
2937 /* This should not occur, since a FIN has been received from the
2938 * remote side. Ignore the segment text. */
2942 /* 8: check the FIN bit */
2946 TCP_EVT (TCP_EVT_FIN_RCVD, tc0);
2950 case TCP_STATE_ESTABLISHED:
2951 /* Account for the FIN and send ack */
2953 tcp_program_ack (tc0);
2954 tcp_connection_set_state (tc0, TCP_STATE_CLOSE_WAIT);
2955 tcp_program_disconnect (wrk, tc0);
2956 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
2958 case TCP_STATE_SYN_RCVD:
2959 /* Send FIN-ACK, enter LAST-ACK and because the app was not
2960 * notified yet, set a cleanup timer instead of relying on
2961 * disconnect notify and the implicit close call. */
2962 tcp_connection_timers_reset (tc0);
2965 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2966 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
2968 case TCP_STATE_CLOSE_WAIT:
2969 case TCP_STATE_CLOSING:
2970 case TCP_STATE_LAST_ACK:
2973 case TCP_STATE_FIN_WAIT_1:
2976 if (tc0->flags & TCP_CONN_FINPNDG)
2978 /* If data is outstanding, stay in FIN_WAIT_1 and try to finish
2979 * sending it. Since we already received a fin, do not wait
2981 tc0->flags |= TCP_CONN_FINRCVD;
2982 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2983 tcp_cfg.closewait_time);
2987 tcp_connection_set_state (tc0, TCP_STATE_CLOSING);
2988 tcp_program_ack (tc0);
2989 /* Wait for ACK for our FIN but not forever */
2990 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2991 tcp_cfg.closing_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_cfg.timewait_time);
3000 tcp_program_ack (tc0);
3001 session_transport_closed_notify (&tc0->connection);
3003 case TCP_STATE_TIME_WAIT:
3004 /* Remain in the TIME-WAIT state. Restart the time-wait
3007 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time);
3010 error0 = TCP_ERROR_FIN_RCVD;
3014 tcp_inc_counter (rcv_process, error0, 1);
3015 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3017 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3018 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
3022 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
3024 tcp_inc_counter (rcv_process, TCP_ERROR_MSG_QUEUE_FULL, errors);
3025 tcp_handle_postponed_dequeues (wrk);
3026 tcp_handle_disconnects (wrk);
3027 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3029 return from_frame->n_vectors;
3032 VLIB_NODE_FN (tcp4_rcv_process_node) (vlib_main_t * vm,
3033 vlib_node_runtime_t * node,
3034 vlib_frame_t * from_frame)
3036 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3039 VLIB_NODE_FN (tcp6_rcv_process_node) (vlib_main_t * vm,
3040 vlib_node_runtime_t * node,
3041 vlib_frame_t * from_frame)
3043 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3047 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
3049 .name = "tcp4-rcv-process",
3050 /* Takes a vector of packets. */
3051 .vector_size = sizeof (u32),
3052 .n_errors = TCP_N_ERROR,
3053 .error_strings = tcp_error_strings,
3054 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3057 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3058 foreach_tcp_state_next
3061 .format_trace = format_tcp_rx_trace_short,
3066 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
3068 .name = "tcp6-rcv-process",
3069 /* Takes a vector of packets. */
3070 .vector_size = sizeof (u32),
3071 .n_errors = TCP_N_ERROR,
3072 .error_strings = tcp_error_strings,
3073 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3076 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3077 foreach_tcp_state_next
3080 .format_trace = format_tcp_rx_trace_short,
3085 * LISTEN state processing as per RFC 793 p. 65
3088 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3089 vlib_frame_t * from_frame, int is_ip4)
3091 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3092 u32 my_thread_index = vm->thread_index;
3094 from = first_buffer = vlib_frame_vector_args (from_frame);
3095 n_left_from = from_frame->n_vectors;
3097 while (n_left_from > 0)
3102 tcp_header_t *th0 = 0;
3103 tcp_connection_t *lc0;
3106 tcp_connection_t *child0;
3107 u32 error0 = TCP_ERROR_NONE;
3113 b0 = vlib_get_buffer (vm, bi0);
3114 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3118 ip40 = vlib_buffer_get_current (b0);
3119 th0 = ip4_next_header (ip40);
3123 ip60 = vlib_buffer_get_current (b0);
3124 th0 = ip6_next_header (ip60);
3127 /* Create child session. For syn-flood protection use filter */
3129 /* 1. first check for an RST: handled in dispatch */
3130 /* if (tcp_rst (th0))
3134 /* 2. second check for an ACK: handled in dispatch */
3135 /* if (tcp_ack (th0))
3137 tcp_send_reset (b0, is_ip4);
3142 /* 3. check for a SYN (did that already) */
3144 /* Make sure connection wasn't just created */
3145 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3147 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3149 error0 = TCP_ERROR_CREATE_EXISTS;
3153 /* Create child session and send SYN-ACK */
3154 child0 = tcp_connection_alloc (my_thread_index);
3155 child0->c_lcl_port = th0->dst_port;
3156 child0->c_rmt_port = th0->src_port;
3157 child0->c_is_ip4 = is_ip4;
3158 child0->state = TCP_STATE_SYN_RCVD;
3159 child0->c_fib_index = lc0->c_fib_index;
3160 child0->cc_algo = lc0->cc_algo;
3164 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3165 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3169 clib_memcpy_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3170 sizeof (ip6_address_t));
3171 clib_memcpy_fast (&child0->c_rmt_ip6, &ip60->src_address,
3172 sizeof (ip6_address_t));
3175 if (tcp_options_parse (th0, &child0->rcv_opts, 1))
3177 error0 = TCP_ERROR_OPTIONS;
3178 tcp_connection_free (child0);
3182 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3183 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3184 child0->rcv_las = child0->rcv_nxt;
3185 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3187 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3188 * segments are used to initialize PAWS. */
3189 if (tcp_opts_tstamp (&child0->rcv_opts))
3191 child0->tsval_recent = child0->rcv_opts.tsval;
3192 child0->tsval_recent_age = tcp_time_now ();
3195 if (tcp_opts_wscale (&child0->rcv_opts))
3196 child0->snd_wscale = child0->rcv_opts.wscale;
3198 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3199 << child0->snd_wscale;
3200 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3201 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3203 tcp_connection_init_vars (child0);
3204 child0->rto = TCP_RTO_MIN;
3206 if (session_stream_accept (&child0->connection, lc0->c_s_index,
3207 lc0->c_thread_index, 0 /* notify */ ))
3209 tcp_connection_cleanup (child0);
3210 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3214 TCP_EVT (TCP_EVT_SYN_RCVD, child0, 1);
3215 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3216 tcp_send_synack (child0);
3220 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3222 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3223 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3224 clib_memcpy_fast (&t0->tcp_connection, lc0,
3225 sizeof (t0->tcp_connection));
3228 n_syns += (error0 == TCP_ERROR_NONE);
3231 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3232 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3234 return from_frame->n_vectors;
3237 VLIB_NODE_FN (tcp4_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3238 vlib_frame_t * from_frame)
3240 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3243 VLIB_NODE_FN (tcp6_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3244 vlib_frame_t * from_frame)
3246 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3250 VLIB_REGISTER_NODE (tcp4_listen_node) =
3252 .name = "tcp4-listen",
3253 /* Takes a vector of packets. */
3254 .vector_size = sizeof (u32),
3255 .n_errors = TCP_N_ERROR,
3256 .error_strings = tcp_error_strings,
3257 .n_next_nodes = TCP_LISTEN_N_NEXT,
3260 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3261 foreach_tcp_state_next
3264 .format_trace = format_tcp_rx_trace_short,
3269 VLIB_REGISTER_NODE (tcp6_listen_node) =
3271 .name = "tcp6-listen",
3272 /* Takes a vector of packets. */
3273 .vector_size = sizeof (u32),
3274 .n_errors = TCP_N_ERROR,
3275 .error_strings = tcp_error_strings,
3276 .n_next_nodes = TCP_LISTEN_N_NEXT,
3279 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3280 foreach_tcp_state_next
3283 .format_trace = format_tcp_rx_trace_short,
3287 typedef enum _tcp_input_next
3289 TCP_INPUT_NEXT_DROP,
3290 TCP_INPUT_NEXT_LISTEN,
3291 TCP_INPUT_NEXT_RCV_PROCESS,
3292 TCP_INPUT_NEXT_SYN_SENT,
3293 TCP_INPUT_NEXT_ESTABLISHED,
3294 TCP_INPUT_NEXT_RESET,
3295 TCP_INPUT_NEXT_PUNT,
3299 #define foreach_tcp4_input_next \
3300 _ (DROP, "ip4-drop") \
3301 _ (LISTEN, "tcp4-listen") \
3302 _ (RCV_PROCESS, "tcp4-rcv-process") \
3303 _ (SYN_SENT, "tcp4-syn-sent") \
3304 _ (ESTABLISHED, "tcp4-established") \
3305 _ (RESET, "tcp4-reset") \
3306 _ (PUNT, "ip4-punt")
3308 #define foreach_tcp6_input_next \
3309 _ (DROP, "ip6-drop") \
3310 _ (LISTEN, "tcp6-listen") \
3311 _ (RCV_PROCESS, "tcp6-rcv-process") \
3312 _ (SYN_SENT, "tcp6-syn-sent") \
3313 _ (ESTABLISHED, "tcp6-established") \
3314 _ (RESET, "tcp6-reset") \
3315 _ (PUNT, "ip6-punt")
3317 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3320 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3321 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3323 tcp_connection_t *tc;
3328 for (i = 0; i < n_bufs; i++)
3330 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3332 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3333 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3335 tcp = vlib_buffer_get_current (bs[i]);
3336 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3342 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3344 if (*error == TCP_ERROR_FILTERED || *error == TCP_ERROR_WRONG_THREAD)
3346 *next = TCP_INPUT_NEXT_DROP;
3348 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3350 *next = TCP_INPUT_NEXT_PUNT;
3351 *error = TCP_ERROR_PUNT;
3355 *next = TCP_INPUT_NEXT_RESET;
3356 *error = TCP_ERROR_NO_LISTENER;
3360 always_inline tcp_connection_t *
3361 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3362 u8 is_ip4, u8 is_nolookup)
3364 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3365 int n_advance_bytes, n_data_bytes;
3366 transport_connection_t *tc;
3372 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3373 int ip_hdr_bytes = ip4_header_bytes (ip4);
3374 if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
3376 *error = TCP_ERROR_LENGTH;
3379 tcp = ip4_next_header (ip4);
3380 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3381 n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
3382 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3384 /* Length check. Checksum computed by ipx_local no need to compute again */
3385 if (PREDICT_FALSE (n_data_bytes < 0))
3387 *error = TCP_ERROR_LENGTH;
3392 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3393 &ip4->src_address, tcp->dst_port,
3395 TRANSPORT_PROTO_TCP, thread_index,
3400 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3401 if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
3403 *error = TCP_ERROR_LENGTH;
3406 tcp = ip6_next_header (ip6);
3407 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3408 n_advance_bytes = tcp_header_bytes (tcp);
3409 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3411 n_advance_bytes += sizeof (ip6[0]);
3413 if (PREDICT_FALSE (n_data_bytes < 0))
3415 *error = TCP_ERROR_LENGTH;
3422 (ip6_address_is_link_local_unicast (&ip6->dst_address)))
3424 ip4_main_t *im = &ip4_main;
3425 fib_index = vec_elt (im->fib_index_by_sw_if_index,
3426 vnet_buffer (b)->sw_if_index[VLIB_RX]);
3429 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3431 tcp->dst_port, tcp->src_port,
3432 TRANSPORT_PROTO_TCP,
3433 thread_index, &result);
3439 (transport_connection_t *) tcp_connection_get (vnet_buffer (b)->
3440 tcp.connection_index,
3443 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3444 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3445 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3446 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3447 vnet_buffer (b)->tcp.seq_end = vnet_buffer (b)->tcp.seq_number
3449 vnet_buffer (b)->tcp.flags = 0;
3451 *error = result ? TCP_ERROR_NONE + result : *error;
3453 return tcp_get_connection_from_transport (tc);
3457 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3458 vlib_buffer_t * b, u16 * next, u32 * error)
3463 tcp = tcp_buffer_hdr (b);
3464 flags = tcp->flags & filter_flags;
3465 *next = tm->dispatch_table[tc->state][flags].next;
3466 *error = tm->dispatch_table[tc->state][flags].error;
3469 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3470 || *next == TCP_INPUT_NEXT_RESET))
3472 /* Overload tcp flags to store state */
3473 tcp_state_t state = tc->state;
3474 vnet_buffer (b)->tcp.flags = tc->state;
3476 if (*error == TCP_ERROR_DISPATCH)
3477 clib_warning ("tcp conn %u disp error state %U flags %U",
3478 tc->c_c_index, format_tcp_state, state,
3479 format_tcp_flags, (int) flags);
3484 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3485 vlib_frame_t * frame, int is_ip4, u8 is_nolookup)
3487 u32 n_left_from, *from, thread_index = vm->thread_index;
3488 tcp_main_t *tm = vnet_get_tcp_main ();
3489 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3490 u16 nexts[VLIB_FRAME_SIZE], *next;
3492 tcp_set_time_now (tcp_get_worker (thread_index));
3494 from = vlib_frame_vector_args (frame);
3495 n_left_from = frame->n_vectors;
3496 vlib_get_buffers (vm, from, bufs, n_left_from);
3501 while (n_left_from >= 4)
3503 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3504 tcp_connection_t *tc0, *tc1;
3507 vlib_prefetch_buffer_header (b[2], STORE);
3508 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3510 vlib_prefetch_buffer_header (b[3], STORE);
3511 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3514 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3516 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3518 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4,
3521 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3523 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3524 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3526 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3527 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3529 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3530 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3534 if (PREDICT_TRUE (tc0 != 0))
3536 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3537 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3538 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3541 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3543 if (PREDICT_TRUE (tc1 != 0))
3545 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3546 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3547 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3550 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3557 while (n_left_from > 0)
3559 tcp_connection_t *tc0;
3560 u32 error0 = TCP_ERROR_NO_LISTENER;
3562 if (n_left_from > 1)
3564 vlib_prefetch_buffer_header (b[1], STORE);
3565 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3568 next[0] = TCP_INPUT_NEXT_DROP;
3569 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4,
3571 if (PREDICT_TRUE (tc0 != 0))
3573 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3574 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3575 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3578 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3585 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3586 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3588 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3589 return frame->n_vectors;
3592 VLIB_NODE_FN (tcp4_input_nolookup_node) (vlib_main_t * vm,
3593 vlib_node_runtime_t * node,
3594 vlib_frame_t * from_frame)
3596 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ,
3597 1 /* is_nolookup */ );
3600 VLIB_NODE_FN (tcp6_input_nolookup_node) (vlib_main_t * vm,
3601 vlib_node_runtime_t * node,
3602 vlib_frame_t * from_frame)
3604 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3605 1 /* is_nolookup */ );
3609 VLIB_REGISTER_NODE (tcp4_input_nolookup_node) =
3611 .name = "tcp4-input-nolookup",
3612 /* Takes a vector of packets. */
3613 .vector_size = sizeof (u32),
3614 .n_errors = TCP_N_ERROR,
3615 .error_strings = tcp_error_strings,
3616 .n_next_nodes = TCP_INPUT_N_NEXT,
3619 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3620 foreach_tcp4_input_next
3623 .format_buffer = format_tcp_header,
3624 .format_trace = format_tcp_rx_trace,
3629 VLIB_REGISTER_NODE (tcp6_input_nolookup_node) =
3631 .name = "tcp6-input-nolookup",
3632 /* Takes a vector of packets. */
3633 .vector_size = sizeof (u32),
3634 .n_errors = TCP_N_ERROR,
3635 .error_strings = tcp_error_strings,
3636 .n_next_nodes = TCP_INPUT_N_NEXT,
3639 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3640 foreach_tcp6_input_next
3643 .format_buffer = format_tcp_header,
3644 .format_trace = format_tcp_rx_trace,
3648 VLIB_NODE_FN (tcp4_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3649 vlib_frame_t * from_frame)
3651 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ,
3652 0 /* is_nolookup */ );
3655 VLIB_NODE_FN (tcp6_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3656 vlib_frame_t * from_frame)
3658 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ,
3659 0 /* is_nolookup */ );
3663 VLIB_REGISTER_NODE (tcp4_input_node) =
3665 .name = "tcp4-input",
3666 /* Takes a vector of packets. */
3667 .vector_size = sizeof (u32),
3668 .n_errors = TCP_N_ERROR,
3669 .error_strings = tcp_error_strings,
3670 .n_next_nodes = TCP_INPUT_N_NEXT,
3673 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3674 foreach_tcp4_input_next
3677 .format_buffer = format_tcp_header,
3678 .format_trace = format_tcp_rx_trace,
3683 VLIB_REGISTER_NODE (tcp6_input_node) =
3685 .name = "tcp6-input",
3686 /* Takes a vector of packets. */
3687 .vector_size = sizeof (u32),
3688 .n_errors = TCP_N_ERROR,
3689 .error_strings = tcp_error_strings,
3690 .n_next_nodes = TCP_INPUT_N_NEXT,
3693 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3694 foreach_tcp6_input_next
3697 .format_buffer = format_tcp_header,
3698 .format_trace = format_tcp_rx_trace,
3702 #ifndef CLIB_MARCH_VARIANT
3704 tcp_dispatch_table_init (tcp_main_t * tm)
3707 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3708 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3710 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3711 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3714 #define _(t,f,n,e) \
3716 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3717 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3720 /* RFC 793: In LISTEN if RST drop and if ACK return RST */
3721 _(LISTEN, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3722 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_ACK_INVALID);
3723 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_INVALID_CONNECTION);
3724 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3725 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3726 TCP_ERROR_ACK_INVALID);
3727 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3728 TCP_ERROR_SEGMENT_INVALID);
3729 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3730 TCP_ERROR_SEGMENT_INVALID);
3731 _(LISTEN, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3732 TCP_ERROR_INVALID_CONNECTION);
3733 _(LISTEN, TCP_FLAG_FIN, TCP_INPUT_NEXT_RESET, TCP_ERROR_SEGMENT_INVALID);
3734 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3735 TCP_ERROR_SEGMENT_INVALID);
3736 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3737 TCP_ERROR_SEGMENT_INVALID);
3738 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3740 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_DROP,
3741 TCP_ERROR_SEGMENT_INVALID);
3742 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3743 TCP_ERROR_SEGMENT_INVALID);
3744 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3745 TCP_ERROR_SEGMENT_INVALID);
3746 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3747 TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3748 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3749 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3750 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3751 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3753 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3754 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3756 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3758 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3759 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3760 _(SYN_RCVD, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3761 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3763 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3765 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3766 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3767 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3769 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3770 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3771 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3772 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3773 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3774 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3775 _(SYN_RCVD, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3776 /* SYN-ACK for a SYN */
3777 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3779 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3780 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3781 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3783 _(SYN_SENT, TCP_FLAG_FIN, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3784 _(SYN_SENT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3786 /* ACK for for established connection -> tcp-established. */
3787 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3788 /* FIN for for established connection -> tcp-established. */
3789 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3790 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3792 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3794 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3795 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3796 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED,
3798 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3799 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3800 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3801 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3802 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3803 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3804 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3805 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3807 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3808 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3810 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3812 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3813 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3814 _(ESTABLISHED, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3815 /* ACK or FIN-ACK to our FIN */
3816 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3817 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3819 /* FIN in reply to our FIN from the other side */
3820 _(FIN_WAIT_1, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3821 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3822 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3824 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3825 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3826 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3827 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3828 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3829 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3830 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3832 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3833 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3834 _(FIN_WAIT_1, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3835 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3837 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3839 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3840 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3841 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3842 _(FIN_WAIT_1, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3844 _(CLOSING, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3845 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3846 _(CLOSING, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3847 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3849 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3851 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3852 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3853 _(CLOSING, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3854 _(CLOSING, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3856 _(CLOSING, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3857 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3859 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3861 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3862 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3863 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3865 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3866 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3867 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3868 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3869 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3870 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3871 /* FIN confirming that the peer (app) has closed */
3872 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3873 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3874 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3876 _(FIN_WAIT_2, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3877 _(FIN_WAIT_2, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3879 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3880 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3882 _(CLOSE_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3883 _(CLOSE_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3885 _(LAST_ACK, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3886 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3887 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3888 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3890 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3892 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3893 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3894 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3896 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3897 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3898 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3899 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3900 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3901 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3902 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3903 _(LAST_ACK, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3905 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3906 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3908 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3910 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3911 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3912 _(TIME_WAIT, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3913 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3914 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3916 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3917 _(TIME_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3919 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3920 /* RFC793 CLOSED: An incoming segment containing a RST is discarded. An
3921 * incoming segment not containing a RST causes a RST to be sent in
3923 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3924 _(CLOSED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3925 TCP_ERROR_CONNECTION_CLOSED);
3926 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3927 _(CLOSED, TCP_FLAG_SYN, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3928 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3933 static clib_error_t *
3934 tcp_input_init (vlib_main_t * vm)
3936 clib_error_t *error = 0;
3937 tcp_main_t *tm = vnet_get_tcp_main ();
3939 if ((error = vlib_call_init_function (vm, tcp_init)))
3942 /* Initialize dispatch table. */
3943 tcp_dispatch_table_init (tm);
3948 VLIB_INIT_FUNCTION (tcp_input_init);
3950 #endif /* CLIB_MARCH_VARIANT */
3953 * fd.io coding-style-patch-verification: ON
3956 * eval: (c-set-style "gnu")