2 * Copyright (c) 2016-2019 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
16 #include <vppinfra/sparse_vec.h>
17 #include <vnet/tcp/tcp_packet.h>
18 #include <vnet/tcp/tcp.h>
19 #include <vnet/session/session.h>
22 static char *tcp_error_strings[] = {
23 #define tcp_error(n,s) s,
24 #include <vnet/tcp/tcp_error.def>
28 /* All TCP nodes have the same outgoing arcs */
29 #define foreach_tcp_state_next \
30 _ (DROP4, "ip4-drop") \
31 _ (DROP6, "ip6-drop") \
32 _ (TCP4_OUTPUT, "tcp4-output") \
33 _ (TCP6_OUTPUT, "tcp6-output")
35 typedef enum _tcp_established_next
37 #define _(s,n) TCP_ESTABLISHED_NEXT_##s,
38 foreach_tcp_state_next
40 TCP_ESTABLISHED_N_NEXT,
41 } tcp_established_next_t;
43 typedef enum _tcp_rcv_process_next
45 #define _(s,n) TCP_RCV_PROCESS_NEXT_##s,
46 foreach_tcp_state_next
48 TCP_RCV_PROCESS_N_NEXT,
49 } tcp_rcv_process_next_t;
51 typedef enum _tcp_syn_sent_next
53 #define _(s,n) TCP_SYN_SENT_NEXT_##s,
54 foreach_tcp_state_next
57 } tcp_syn_sent_next_t;
59 typedef enum _tcp_listen_next
61 #define _(s,n) TCP_LISTEN_NEXT_##s,
62 foreach_tcp_state_next
67 /* Generic, state independent indices */
68 typedef enum _tcp_state_next
70 #define _(s,n) TCP_NEXT_##s,
71 foreach_tcp_state_next
76 #define tcp_next_output(is_ip4) (is_ip4 ? TCP_NEXT_TCP4_OUTPUT \
77 : TCP_NEXT_TCP6_OUTPUT)
79 #define tcp_next_drop(is_ip4) (is_ip4 ? TCP_NEXT_DROP4 \
83 * Validate segment sequence number. As per RFC793:
85 * Segment Receive Test
87 * ------- ------- -------------------------------------------
88 * 0 0 SEG.SEQ = RCV.NXT
89 * 0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
91 * >0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
92 * or RCV.NXT =< SEG.SEQ+SEG.LEN-1 < RCV.NXT+RCV.WND
94 * This ultimately consists in checking if segment falls within the window.
95 * The one important difference compared to RFC793 is that we use rcv_las,
96 * or the rcv_nxt at last ack sent instead of rcv_nxt since that's the
97 * peer's reference when computing our receive window.
100 * seq_leq (end_seq, tc->rcv_las + tc->rcv_wnd) && seq_geq (seq, tc->rcv_las)
101 * however, is too strict when we have retransmits. Instead we just check that
102 * the seq is not beyond the right edge and that the end of the segment is not
103 * less than the left edge.
105 * N.B. rcv_nxt and rcv_wnd are both updated in this node if acks are sent, so
106 * use rcv_nxt in the right edge window test instead of rcv_las.
110 tcp_segment_in_rcv_wnd (tcp_connection_t * tc, u32 seq, u32 end_seq)
112 return (seq_geq (end_seq, tc->rcv_las)
113 && seq_leq (seq, tc->rcv_nxt + tc->rcv_wnd));
117 * Parse TCP header options.
119 * @param th TCP header
120 * @param to TCP options data structure to be populated
121 * @param is_syn set if packet is syn
122 * @return -1 if parsing failed
125 tcp_options_parse (tcp_header_t * th, tcp_options_t * to, u8 is_syn)
128 u8 opt_len, opts_len, kind;
132 opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t);
133 data = (const u8 *) (th + 1);
135 /* Zero out all flags but those set in SYN */
136 to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE
137 | TCP_OPTS_FLAG_TSTAMP | TCP_OPTION_MSS);
139 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
143 /* Get options length */
144 if (kind == TCP_OPTION_EOL)
146 else if (kind == TCP_OPTION_NOOP)
158 /* weird option length */
159 if (opt_len < 2 || opt_len > opts_len)
169 if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
171 to->flags |= TCP_OPTS_FLAG_MSS;
172 to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
175 case TCP_OPTION_WINDOW_SCALE:
178 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
180 to->flags |= TCP_OPTS_FLAG_WSCALE;
181 to->wscale = data[2];
182 if (to->wscale > TCP_MAX_WND_SCALE)
183 to->wscale = TCP_MAX_WND_SCALE;
186 case TCP_OPTION_TIMESTAMP:
188 to->flags |= TCP_OPTS_FLAG_TSTAMP;
189 if ((to->flags & TCP_OPTS_FLAG_TSTAMP)
190 && opt_len == TCP_OPTION_LEN_TIMESTAMP)
192 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
193 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
196 case TCP_OPTION_SACK_PERMITTED:
199 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
200 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
202 case TCP_OPTION_SACK_BLOCK:
203 /* If SACK permitted was not advertised or a SYN, break */
204 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
207 /* If too short or not correctly formatted, break */
208 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
211 to->flags |= TCP_OPTS_FLAG_SACK;
212 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
213 vec_reset_length (to->sacks);
214 for (j = 0; j < to->n_sack_blocks; j++)
216 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 8 * j));
217 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 8 * j));
218 vec_add1 (to->sacks, b);
222 /* Nothing to see here */
230 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
231 * timestamp to echo and it's less than tsval_recent, drop segment
232 * but still send an ACK in order to retain TCP's mechanism for detecting
233 * and recovering from half-open connections
235 * Or at least that's what the theory says. It seems that this might not work
236 * very well with packet reordering and fast retransmit. XXX
239 tcp_segment_check_paws (tcp_connection_t * tc)
241 return tcp_opts_tstamp (&tc->rcv_opts)
242 && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent);
246 * Update tsval recent
249 tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
252 * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
253 * of an incoming segment:
254 * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
255 * then the TSval from the segment is copied to TS.Recent;
256 * otherwise, the TSval is ignored.
258 if (tcp_opts_tstamp (&tc->rcv_opts) && seq_leq (seq, tc->rcv_las)
259 && seq_leq (tc->rcv_las, seq_end))
261 ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval));
262 tc->tsval_recent = tc->rcv_opts.tsval;
263 tc->tsval_recent_age = tcp_time_now_w_thread (tc->c_thread_index);
268 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
270 * It first verifies if segment has a wrapped sequence number (PAWS) and then
271 * does the processing associated to the first four steps (ignoring security
272 * and precedence): sequence number, rst bit and syn bit checks.
274 * @return 0 if segments passes validation.
277 tcp_segment_validate (tcp_worker_ctx_t * wrk, tcp_connection_t * tc0,
278 vlib_buffer_t * b0, tcp_header_t * th0, u32 * error0)
280 /* We could get a burst of RSTs interleaved with acks */
281 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
283 tcp_send_reset (tc0);
284 *error0 = TCP_ERROR_CONNECTION_CLOSED;
288 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
290 *error0 = TCP_ERROR_SEGMENT_INVALID;
294 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts, 0)))
296 *error0 = TCP_ERROR_OPTIONS;
300 if (PREDICT_FALSE (tcp_segment_check_paws (tc0)))
302 *error0 = TCP_ERROR_PAWS;
303 TCP_EVT_DBG (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
304 vnet_buffer (b0)->tcp.seq_end);
306 /* If it just so happens that a segment updates tsval_recent for a
307 * segment over 24 days old, invalidate tsval_recent. */
308 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
309 tcp_time_now_w_thread (tc0->c_thread_index)))
311 tc0->tsval_recent = tc0->rcv_opts.tsval;
312 clib_warning ("paws failed: 24-day old segment");
314 /* Drop after ack if not rst. Resets can fail paws check as per
315 * RFC 7323 sec. 5.2: When an <RST> segment is received, it MUST NOT
316 * be subjected to the PAWS check by verifying an acceptable value in
318 else if (!tcp_rst (th0))
320 tcp_program_ack (wrk, tc0);
321 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
326 /* 1st: check sequence number */
327 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
328 vnet_buffer (b0)->tcp.seq_end))
330 /* SYN/SYN-ACK retransmit */
332 && vnet_buffer (b0)->tcp.seq_number == tc0->rcv_nxt - 1)
334 tcp_options_parse (th0, &tc0->rcv_opts, 1);
335 if (tc0->state == TCP_STATE_SYN_RCVD)
337 tcp_send_synack (tc0);
338 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0, 0);
339 *error0 = TCP_ERROR_SYNS_RCVD;
343 tcp_program_ack (wrk, tc0);
344 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, tc0);
345 *error0 = TCP_ERROR_SYN_ACKS_RCVD;
350 /* If our window is 0 and the packet is in sequence, let it pass
351 * through for ack processing. It should be dropped later. */
352 if (tc0->rcv_wnd < tc0->snd_mss
353 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number)
356 /* If we entered recovery and peer did so as well, there's a chance that
357 * dup acks won't be acceptable on either end because seq_end may be less
358 * than rcv_las. This can happen if acks are lost in both directions. */
359 if (tcp_in_recovery (tc0)
360 && seq_geq (vnet_buffer (b0)->tcp.seq_number,
361 tc0->rcv_las - tc0->rcv_wnd)
362 && seq_leq (vnet_buffer (b0)->tcp.seq_end,
363 tc0->rcv_nxt + tc0->rcv_wnd))
366 *error0 = TCP_ERROR_RCV_WND;
368 /* If not RST, send dup ack */
371 tcp_program_dupack (wrk, tc0);
372 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
380 /* 2nd: check the RST bit */
381 if (PREDICT_FALSE (tcp_rst (th0)))
383 tcp_connection_reset (tc0);
384 *error0 = TCP_ERROR_RST_RCVD;
388 /* 3rd: check security and precedence (skip) */
390 /* 4th: check the SYN bit (in window) */
391 if (PREDICT_FALSE (tcp_syn (th0)))
393 *error0 = TCP_ERROR_SPURIOUS_SYN;
394 tcp_send_reset (tc0);
398 /* If segment in window, save timestamp */
399 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
400 vnet_buffer (b0)->tcp.seq_end);
408 tcp_rcv_ack_no_cc (tcp_connection_t * tc, vlib_buffer_t * b, u32 * error)
410 /* SND.UNA =< SEG.ACK =< SND.NXT */
411 if (!(seq_leq (tc->snd_una, vnet_buffer (b)->tcp.ack_number)
412 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
414 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
416 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
419 *error = TCP_ERROR_ACK_INVALID;
424 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
425 tc->snd_una = vnet_buffer (b)->tcp.ack_number;
426 *error = TCP_ERROR_ACK_OK;
431 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
433 * Note that although the original article, srtt and rttvar are scaled
434 * to minimize round-off errors, here we don't. Instead, we rely on
435 * better precision time measurements.
437 * TODO support us rtt resolution
440 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
446 err = mrtt - tc->srtt;
448 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
449 * The increase should be bound */
450 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
451 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
452 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
456 /* First measurement. */
458 tc->rttvar = mrtt >> 1;
462 #ifndef CLIB_MARCH_VARIANT
464 tcp_update_rto (tcp_connection_t * tc)
466 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
467 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
469 #endif /* CLIB_MARCH_VARIANT */
472 * Update RTT estimate and RTO timer
474 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
475 * timing. Middle boxes are known to fiddle with TCP options so we
476 * should give higher priority to ACK timing.
478 * This should be called only if previously sent bytes have been acked.
480 * return 1 if valid rtt 0 otherwise
483 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
487 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
488 * RTT because they're ambiguous. */
489 if (tcp_in_cong_recovery (tc) || tc->sack_sb.sacked_bytes)
491 if (tcp_in_recovery (tc))
496 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
498 f64 sample = tcp_time_now_us (tc->c_thread_index) - tc->rtt_ts;
499 tc->mrtt_us = tc->mrtt_us + (sample - tc->mrtt_us) * 0.125;
500 mrtt = clib_max ((u32) (sample * THZ), 1);
501 /* Allow measuring of a new RTT */
504 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
505 * snd_una, i.e., the left side of the send window:
506 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
507 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
509 u32 now = tcp_time_now_w_thread (tc->c_thread_index);
510 mrtt = clib_max (now - tc->rcv_opts.tsecr, 1);
513 /* Ignore dubious measurements */
514 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
517 tcp_estimate_rtt (tc, mrtt);
521 /* If we got here something must've been ACKed so make sure boff is 0,
522 * even if mrtt is not valid since we update the rto lower */
530 tcp_estimate_initial_rtt (tcp_connection_t * tc)
532 u8 thread_index = vlib_num_workers ()? 1 : 0;
537 tc->mrtt_us = tcp_time_now_us (thread_index) - tc->rtt_ts;
538 tc->mrtt_us = clib_max (tc->mrtt_us, 0.0001);
539 mrtt = clib_max ((u32) (tc->mrtt_us * THZ), 1);
544 mrtt = tcp_time_now_w_thread (thread_index) - tc->rcv_opts.tsecr;
545 mrtt = clib_max (mrtt, 1);
546 /* Due to retransmits we don't know the initial mrtt */
547 if (tc->rto_boff && mrtt > 1 * THZ)
549 tc->mrtt_us = (f64) mrtt *TCP_TICK;
552 if (mrtt > 0 && mrtt < TCP_RTT_MAX)
553 tcp_estimate_rtt (tc, mrtt);
558 * Dequeue bytes for connections that have received acks in last burst
561 tcp_handle_postponed_dequeues (tcp_worker_ctx_t * wrk)
563 u32 thread_index = wrk->vm->thread_index;
564 u32 *pending_deq_acked;
565 tcp_connection_t *tc;
568 if (!vec_len (wrk->pending_deq_acked))
571 pending_deq_acked = wrk->pending_deq_acked;
572 for (i = 0; i < vec_len (pending_deq_acked); i++)
574 tc = tcp_connection_get (pending_deq_acked[i], thread_index);
575 tc->flags &= ~TCP_CONN_DEQ_PENDING;
577 if (PREDICT_FALSE (!tc->burst_acked))
580 /* Dequeue the newly ACKed bytes */
581 session_tx_fifo_dequeue_drop (&tc->connection, tc->burst_acked);
583 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
585 if (PREDICT_FALSE (tc->flags & TCP_CONN_PSH_PENDING))
587 if (seq_leq (tc->psh_seq, tc->snd_una))
588 tc->flags &= ~TCP_CONN_PSH_PENDING;
591 /* If everything has been acked, stop retransmit timer
592 * otherwise update. */
593 tcp_retransmit_timer_update (tc);
595 /* If not congested, update pacer based on our new
597 if (!tcp_in_fastrecovery (tc))
598 tcp_connection_tx_pacer_update (tc);
600 _vec_len (wrk->pending_deq_acked) = 0;
604 tcp_program_dequeue (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
606 if (!(tc->flags & TCP_CONN_DEQ_PENDING))
608 vec_add1 (wrk->pending_deq_acked, tc->c_c_index);
609 tc->flags |= TCP_CONN_DEQ_PENDING;
611 tc->burst_acked += tc->bytes_acked + tc->sack_sb.snd_una_adv;
615 * Check if duplicate ack as per RFC5681 Sec. 2
618 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
621 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
622 && seq_gt (tc->snd_nxt, tc->snd_una)
623 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
624 && (prev_snd_wnd == tc->snd_wnd));
628 * Checks if ack is a congestion control event.
631 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
632 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
634 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
635 * defined to be 'duplicate' */
636 *is_dack = tc->sack_sb.last_sacked_bytes
637 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
639 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
642 #ifndef CLIB_MARCH_VARIANT
644 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
646 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
647 return hole - sb->holes;
651 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
653 return hole->end - hole->start;
656 sack_scoreboard_hole_t *
657 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
659 if (index != TCP_INVALID_SACK_HOLE_INDEX)
660 return pool_elt_at_index (sb->holes, index);
664 sack_scoreboard_hole_t *
665 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
667 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
668 return pool_elt_at_index (sb->holes, hole->next);
672 sack_scoreboard_hole_t *
673 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
675 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
676 return pool_elt_at_index (sb->holes, hole->prev);
680 sack_scoreboard_hole_t *
681 scoreboard_first_hole (sack_scoreboard_t * sb)
683 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
684 return pool_elt_at_index (sb->holes, sb->head);
688 sack_scoreboard_hole_t *
689 scoreboard_last_hole (sack_scoreboard_t * sb)
691 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
692 return pool_elt_at_index (sb->holes, sb->tail);
697 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
699 sack_scoreboard_hole_t *next, *prev;
701 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
703 next = pool_elt_at_index (sb->holes, hole->next);
704 next->prev = hole->prev;
708 sb->tail = hole->prev;
711 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
713 prev = pool_elt_at_index (sb->holes, hole->prev);
714 prev->next = hole->next;
718 sb->head = hole->next;
721 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
722 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
724 /* Poison the entry */
726 clib_memset (hole, 0xfe, sizeof (*hole));
728 pool_put (sb->holes, hole);
731 static sack_scoreboard_hole_t *
732 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
735 sack_scoreboard_hole_t *hole, *next, *prev;
738 pool_get (sb->holes, hole);
739 clib_memset (hole, 0, sizeof (*hole));
743 hole_index = scoreboard_hole_index (sb, hole);
745 prev = scoreboard_get_hole (sb, prev_index);
748 hole->prev = prev_index;
749 hole->next = prev->next;
751 if ((next = scoreboard_next_hole (sb, hole)))
752 next->prev = hole_index;
754 sb->tail = hole_index;
756 prev->next = hole_index;
760 sb->head = hole_index;
761 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
762 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
767 #endif /* CLIB_MARCH_VARIANT */
769 #ifndef CLIB_MARCH_VARIANT
771 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
773 sack_scoreboard_hole_t *left, *right;
774 u32 bytes = 0, blks = 0;
777 sb->sacked_bytes = 0;
778 left = scoreboard_last_hole (sb);
782 if (seq_gt (sb->high_sacked, left->end))
784 bytes = sb->high_sacked - left->end;
788 while ((right = left)
789 && bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
790 && blks < TCP_DUPACK_THRESHOLD
791 /* left not updated if above conditions fail */
792 && (left = scoreboard_prev_hole (sb, right)))
794 bytes += right->start - left->end;
798 /* left is first lost */
803 sb->lost_bytes += scoreboard_hole_bytes (right);
805 left = scoreboard_prev_hole (sb, right);
807 bytes += right->start - left->end;
809 while ((right = left));
812 sb->sacked_bytes = bytes;
816 * Figure out the next hole to retransmit
818 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
820 sack_scoreboard_hole_t *
821 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
822 sack_scoreboard_hole_t * start,
823 u8 have_unsent, u8 * can_rescue, u8 * snd_limited)
825 sack_scoreboard_hole_t *hole = 0;
827 hole = start ? start : scoreboard_first_hole (sb);
828 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
829 hole = scoreboard_next_hole (sb, hole);
831 /* Nothing, return */
834 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
838 /* Rule (1): if higher than rxt, less than high_sacked and lost */
839 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
841 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
845 /* Rule (2): available unsent data */
848 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
851 /* Rule (3): if hole not lost */
852 else if (seq_lt (hole->start, sb->high_sacked))
855 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
857 /* Rule (4): if hole beyond high_sacked */
860 ASSERT (seq_geq (hole->start, sb->high_sacked));
863 /* HighRxt MUST NOT be updated */
868 if (hole && seq_lt (sb->high_rxt, hole->start))
869 sb->high_rxt = hole->start;
873 #endif /* CLIB_MARCH_VARIANT */
876 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 snd_una)
878 sack_scoreboard_hole_t *hole;
879 hole = scoreboard_first_hole (sb);
882 snd_una = seq_gt (snd_una, hole->start) ? snd_una : hole->start;
883 sb->cur_rxt_hole = sb->head;
885 sb->high_rxt = snd_una;
886 sb->rescue_rxt = snd_una - 1;
889 #ifndef CLIB_MARCH_VARIANT
891 scoreboard_init (sack_scoreboard_t * sb)
893 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
894 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
895 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
899 scoreboard_clear (sack_scoreboard_t * sb)
901 sack_scoreboard_hole_t *hole;
902 while ((hole = scoreboard_first_hole (sb)))
904 scoreboard_remove_hole (sb, hole);
906 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
907 ASSERT (pool_elts (sb->holes) == 0);
908 sb->sacked_bytes = 0;
909 sb->last_sacked_bytes = 0;
910 sb->last_bytes_delivered = 0;
915 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
917 #endif /* CLIB_MARCH_VARIANT */
920 * Test that scoreboard is sane after recovery
922 * Returns 1 if scoreboard is empty or if first hole beyond
926 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
928 sack_scoreboard_hole_t *hole;
929 hole = scoreboard_first_hole (&tc->sack_sb);
930 return (!hole || (seq_geq (hole->start, tc->snd_una)
931 && seq_lt (hole->end, tc->snd_nxt)));
934 #ifndef CLIB_MARCH_VARIANT
936 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
938 sack_scoreboard_t *sb = &tc->sack_sb;
939 sack_block_t *blk, tmp;
940 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
941 u32 blk_index = 0, old_sacked_bytes, hole_index;
944 sb->last_sacked_bytes = 0;
945 sb->last_bytes_delivered = 0;
948 if (!tcp_opts_sack (&tc->rcv_opts)
949 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
952 old_sacked_bytes = sb->sacked_bytes;
954 /* Remove invalid blocks */
955 blk = tc->rcv_opts.sacks;
956 while (blk < vec_end (tc->rcv_opts.sacks))
958 if (seq_lt (blk->start, blk->end)
959 && seq_gt (blk->start, tc->snd_una)
960 && seq_gt (blk->start, ack)
961 && seq_lt (blk->start, tc->snd_nxt)
962 && seq_leq (blk->end, tc->snd_nxt))
967 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
970 /* Add block for cumulative ack */
971 if (seq_gt (ack, tc->snd_una))
973 tmp.start = tc->snd_una;
975 vec_add1 (tc->rcv_opts.sacks, tmp);
978 if (vec_len (tc->rcv_opts.sacks) == 0)
981 tcp_scoreboard_trace_add (tc, ack);
983 /* Make sure blocks are ordered */
984 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
985 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
986 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
988 tmp = tc->rcv_opts.sacks[i];
989 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
990 tc->rcv_opts.sacks[j] = tmp;
993 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
995 /* If no holes, insert the first that covers all outstanding bytes */
996 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
997 tc->snd_una, tc->snd_nxt);
998 sb->tail = scoreboard_hole_index (sb, last_hole);
999 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
1000 sb->high_sacked = tmp.end;
1004 /* If we have holes but snd_una_max is beyond the last hole, update
1006 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
1007 last_hole = scoreboard_last_hole (sb);
1008 if (seq_gt (tc->snd_nxt, last_hole->end))
1010 if (seq_geq (last_hole->start, sb->high_sacked))
1012 last_hole->end = tc->snd_nxt;
1014 /* New hole after high sacked block */
1015 else if (seq_lt (sb->high_sacked, tc->snd_nxt))
1017 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
1021 /* Keep track of max byte sacked for when the last hole
1023 if (seq_gt (tmp.end, sb->high_sacked))
1024 sb->high_sacked = tmp.end;
1027 /* Walk the holes with the SACK blocks */
1028 hole = pool_elt_at_index (sb->holes, sb->head);
1029 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
1031 blk = &tc->rcv_opts.sacks[blk_index];
1032 if (seq_leq (blk->start, hole->start))
1034 /* Block covers hole. Remove hole */
1035 if (seq_geq (blk->end, hole->end))
1037 next_hole = scoreboard_next_hole (sb, hole);
1039 /* Byte accounting: snd_una needs to be advanced */
1040 if (blk->end == ack)
1044 if (seq_lt (ack, next_hole->start))
1045 sb->snd_una_adv = next_hole->start - ack;
1046 sb->last_bytes_delivered +=
1047 next_hole->start - hole->end;
1051 ASSERT (seq_geq (sb->high_sacked, ack));
1052 sb->snd_una_adv = sb->high_sacked - ack;
1053 sb->last_bytes_delivered += sb->high_sacked - hole->end;
1057 scoreboard_remove_hole (sb, hole);
1060 /* Partial 'head' overlap */
1063 if (seq_gt (blk->end, hole->start))
1065 hole->start = blk->end;
1072 /* Hole must be split */
1073 if (seq_lt (blk->end, hole->end))
1075 hole_index = scoreboard_hole_index (sb, hole);
1076 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
1079 /* Pool might've moved */
1080 hole = scoreboard_get_hole (sb, hole_index);
1081 hole->end = blk->start;
1083 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
1085 else if (seq_lt (blk->start, hole->end))
1087 hole->end = blk->start;
1089 hole = scoreboard_next_hole (sb, hole);
1093 if (pool_elts (sb->holes) == 1)
1095 hole = scoreboard_first_hole (sb);
1096 if (hole->start == ack + sb->snd_una_adv && hole->end == tc->snd_nxt)
1097 scoreboard_remove_hole (sb, hole);
1100 scoreboard_update_bytes (tc, sb);
1101 sb->last_sacked_bytes = sb->sacked_bytes
1102 - (old_sacked_bytes - sb->last_bytes_delivered);
1103 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
1104 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
1105 || sb->sacked_bytes < tc->snd_nxt - seq_max (tc->snd_una, ack));
1106 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_nxt
1107 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1108 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1109 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
1110 TCP_EVT_DBG (TCP_EVT_CC_SCOREBOARD, tc);
1112 #endif /* CLIB_MARCH_VARIANT */
1115 * Try to update snd_wnd based on feedback received from peer.
1117 * If successful, and new window is 'effectively' 0, activate persist
1121 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1123 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1124 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1125 if (seq_lt (tc->snd_wl1, seq)
1126 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1128 tc->snd_wnd = snd_wnd;
1131 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
1133 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
1135 /* Set persist timer if not set and we just got 0 wnd */
1136 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1137 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1138 tcp_persist_timer_set (tc);
1142 tcp_persist_timer_reset (tc);
1143 if (PREDICT_FALSE (!tcp_in_recovery (tc) && tc->rto_boff > 0))
1146 tcp_update_rto (tc);
1152 #ifndef CLIB_MARCH_VARIANT
1154 * Init loss recovery/fast recovery.
1156 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1157 * updated in @ref tcp_cc_handle_event after fast retransmit
1160 tcp_cc_init_congestion (tcp_connection_t * tc)
1162 tcp_fastrecovery_on (tc);
1163 tc->snd_congestion = tc->snd_nxt;
1164 tc->cwnd_acc_bytes = 0;
1165 tc->snd_rxt_bytes = 0;
1166 tc->prev_ssthresh = tc->ssthresh;
1167 tc->prev_cwnd = tc->cwnd;
1168 tc->cc_algo->congestion (tc);
1169 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
1171 #endif /* CLIB_MARCH_VARIANT */
1174 tcp_cc_recovery_exit (tcp_connection_t * tc)
1177 tcp_update_rto (tc);
1180 tcp_recovery_off (tc);
1181 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1184 #ifndef CLIB_MARCH_VARIANT
1186 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
1188 tc->cc_algo->recovered (tc);
1189 tc->snd_rxt_bytes = 0;
1190 tc->rcv_dupacks = 0;
1191 tc->snd_rxt_bytes = 0;
1194 tcp_fastrecovery_off (tc);
1195 tcp_fastrecovery_first_off (tc);
1197 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1199 #endif /* CLIB_MARCH_VARIANT */
1202 tcp_cc_congestion_undo (tcp_connection_t * tc)
1204 tc->cwnd = tc->prev_cwnd;
1205 tc->ssthresh = tc->prev_ssthresh;
1206 tc->rcv_dupacks = 0;
1207 if (tcp_in_recovery (tc))
1209 tcp_cc_recovery_exit (tc);
1210 tc->snd_nxt = seq_max (tc->snd_nxt, tc->snd_congestion);
1212 else if (tcp_in_fastrecovery (tc))
1214 tcp_cc_fastrecovery_exit (tc);
1216 ASSERT (tc->rto_boff == 0);
1217 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
1221 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1223 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1225 && tcp_opts_tstamp (&tc->rcv_opts)
1226 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1230 tcp_cc_is_spurious_fast_rxt (tcp_connection_t * tc)
1232 return (tcp_in_fastrecovery (tc)
1233 && tc->cwnd > tc->ssthresh + 3 * tc->snd_mss);
1237 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1239 return (tcp_cc_is_spurious_timeout_rxt (tc)
1240 || tcp_cc_is_spurious_fast_rxt (tc));
1244 tcp_cc_recover (tcp_connection_t * tc)
1246 ASSERT (tcp_in_cong_recovery (tc));
1247 if (tcp_cc_is_spurious_retransmit (tc))
1249 tcp_cc_congestion_undo (tc);
1253 if (tcp_in_recovery (tc))
1254 tcp_cc_recovery_exit (tc);
1255 else if (tcp_in_fastrecovery (tc))
1256 tcp_cc_fastrecovery_exit (tc);
1258 ASSERT (tc->rto_boff == 0);
1259 ASSERT (!tcp_in_cong_recovery (tc));
1260 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1265 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
1267 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1269 /* Congestion avoidance */
1270 tcp_cc_rcv_ack (tc);
1272 /* If a cumulative ack, make sure dupacks is 0 */
1273 tc->rcv_dupacks = 0;
1275 /* When dupacks hits the threshold we only enter fast retransmit if
1276 * cumulative ack covers more than snd_congestion. Should snd_una
1277 * wrap this test may fail under otherwise valid circumstances.
1278 * Therefore, proactively update snd_congestion when wrap detected. */
1280 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1281 && seq_gt (tc->snd_congestion, tc->snd_una)))
1282 tc->snd_congestion = tc->snd_una - 1;
1286 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1288 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1292 tcp_should_fastrecover (tcp_connection_t * tc)
1294 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1295 || tcp_should_fastrecover_sack (tc));
1298 #ifndef CLIB_MARCH_VARIANT
1300 tcp_program_fastretransmit (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1302 if (!(tc->flags & TCP_CONN_FRXT_PENDING))
1304 vec_add1 (wrk->pending_fast_rxt, tc->c_c_index);
1305 tc->flags |= TCP_CONN_FRXT_PENDING;
1310 tcp_do_fastretransmits (tcp_worker_ctx_t * wrk)
1312 u32 *ongoing_fast_rxt, burst_bytes, sent_bytes, thread_index;
1313 u32 max_burst_size, burst_size, n_segs = 0, n_segs_now;
1314 tcp_connection_t *tc;
1318 if (vec_len (wrk->pending_fast_rxt) == 0
1319 && vec_len (wrk->postponed_fast_rxt) == 0)
1322 thread_index = wrk->vm->thread_index;
1323 last_cpu_time = wrk->vm->clib_time.last_cpu_time;
1324 ongoing_fast_rxt = wrk->ongoing_fast_rxt;
1325 vec_append (ongoing_fast_rxt, wrk->postponed_fast_rxt);
1326 vec_append (ongoing_fast_rxt, wrk->pending_fast_rxt);
1328 _vec_len (wrk->postponed_fast_rxt) = 0;
1329 _vec_len (wrk->pending_fast_rxt) = 0;
1331 max_burst_size = VLIB_FRAME_SIZE / vec_len (ongoing_fast_rxt);
1332 max_burst_size = clib_max (max_burst_size, 1);
1334 for (i = 0; i < vec_len (ongoing_fast_rxt); i++)
1336 tc = tcp_connection_get (ongoing_fast_rxt[i], thread_index);
1337 if (!tcp_in_fastrecovery (tc))
1339 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1343 if (n_segs >= VLIB_FRAME_SIZE)
1345 vec_add1 (wrk->postponed_fast_rxt, ongoing_fast_rxt[i]);
1349 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1350 burst_size = clib_min (max_burst_size, VLIB_FRAME_SIZE - n_segs);
1351 burst_bytes = transport_connection_tx_pacer_burst (&tc->connection,
1353 burst_size = clib_min (burst_size, burst_bytes / tc->snd_mss);
1356 tcp_program_fastretransmit (wrk, tc);
1360 n_segs_now = tcp_fast_retransmit (wrk, tc, burst_size);
1361 sent_bytes = clib_min (n_segs_now * tc->snd_mss, burst_bytes);
1362 transport_connection_tx_pacer_update_bytes (&tc->connection,
1364 n_segs += n_segs_now;
1366 _vec_len (ongoing_fast_rxt) = 0;
1367 wrk->ongoing_fast_rxt = ongoing_fast_rxt;
1369 #endif /* CLIB_MARCH_VARIANT */
1372 * One function to rule them all ... and in the darkness bind them
1375 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1379 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1381 if (tc->bytes_acked)
1383 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1387 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1388 * it account for the bytes that left the network.
1390 else if (is_dack && !tcp_in_recovery (tc))
1392 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1393 ASSERT (tc->snd_una != tc->snd_nxt || tc->sack_sb.last_sacked_bytes);
1397 /* Pure duplicate ack. If some data got acked, it's handled lower */
1398 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1400 ASSERT (tcp_in_fastrecovery (tc));
1401 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1404 else if (tcp_should_fastrecover (tc))
1408 ASSERT (!tcp_in_fastrecovery (tc));
1410 /* Heuristic to catch potential late dupacks
1411 * after fast retransmit exits */
1412 if (is_dack && tc->snd_una == tc->snd_congestion
1413 && timestamp_leq (tc->rcv_opts.tsecr, tc->tsecr_last_ack))
1415 tc->rcv_dupacks = 0;
1419 tcp_cc_init_congestion (tc);
1420 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1422 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1424 tc->cwnd = tc->ssthresh;
1425 scoreboard_init_high_rxt (&tc->sack_sb, tc->snd_una);
1429 /* Post retransmit update cwnd to ssthresh and account for the
1430 * three segments that have left the network and should've been
1431 * buffered at the receiver XXX */
1432 tc->cwnd = tc->ssthresh + 3 * tc->snd_mss;
1435 /* Constrain rate until we get a partial ack */
1436 pacer_wnd = clib_max (0.1 * tc->cwnd, 2 * tc->snd_mss);
1437 tcp_connection_tx_pacer_reset (tc, pacer_wnd,
1438 0 /* start bucket */ );
1439 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index),
1443 else if (!tc->bytes_acked
1444 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1446 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1452 /* Don't allow entry in fast recovery if still in recovery, for now */
1453 else if (0 && is_dack && tcp_in_recovery (tc))
1455 /* If of of the two conditions lower hold, reset dupacks because
1456 * we're probably after timeout (RFC6582 heuristics).
1457 * If Cumulative ack does not cover more than congestion threshold,
1459 * 1) The following doesn't hold: The congestion window is greater
1460 * than SMSS bytes and the difference between highest_ack
1461 * and prev_highest_ack is at most 4*SMSS bytes
1462 * 2) Echoed timestamp in the last non-dup ack does not equal the
1465 if (seq_leq (tc->snd_una, tc->snd_congestion)
1466 && ((!(tc->cwnd > tc->snd_mss
1467 && tc->bytes_acked <= 4 * tc->snd_mss))
1468 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1470 tc->rcv_dupacks = 0;
1475 if (!tc->bytes_acked)
1479 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1482 * Legitimate ACK. 1) See if we can exit recovery
1485 /* Update the pacing rate. For the first partial ack we move from
1486 * the artificially constrained rate to the one after congestion */
1487 tcp_connection_tx_pacer_update (tc);
1489 if (seq_geq (tc->snd_una, tc->snd_congestion))
1491 tcp_retransmit_timer_update (tc);
1493 /* If spurious return, we've already updated everything */
1494 if (tcp_cc_recover (tc))
1496 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1500 /* Treat as congestion avoidance ack */
1501 tcp_cc_rcv_ack (tc);
1506 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1509 /* XXX limit this only to first partial ack? */
1510 tcp_retransmit_timer_update (tc);
1512 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1513 * reset dupacks to 0. Also needed if in congestion recovery */
1514 tc->rcv_dupacks = 0;
1516 /* Post RTO timeout don't try anything fancy */
1517 if (tcp_in_recovery (tc))
1519 tcp_cc_rcv_ack (tc);
1520 transport_add_tx_event (&tc->connection);
1524 /* Remove retransmitted bytes that have been delivered */
1525 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1527 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1528 >= tc->sack_sb.last_bytes_delivered
1529 || (tc->flags & TCP_CONN_FINSNT));
1531 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1532 * remove sacked bytes delivered */
1533 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1535 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1536 - tc->sack_sb.last_bytes_delivered;
1537 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1538 tc->snd_rxt_bytes -= rxt_delivered;
1542 /* Apparently all retransmitted holes have been acked */
1543 tc->snd_rxt_bytes = 0;
1544 tc->sack_sb.high_rxt = tc->snd_una;
1549 tcp_fastrecovery_first_on (tc);
1550 /* Reuse last bytes delivered to track total bytes acked */
1551 tc->sack_sb.last_bytes_delivered += tc->bytes_acked;
1552 if (tc->snd_rxt_bytes > tc->bytes_acked)
1553 tc->snd_rxt_bytes -= tc->bytes_acked;
1555 tc->snd_rxt_bytes = 0;
1558 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1561 * Since this was a partial ack, try to retransmit some more data
1563 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1567 * Process incoming ACK
1570 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1571 tcp_header_t * th, u32 * error)
1573 u32 prev_snd_wnd, prev_snd_una;
1576 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1578 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1579 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1581 /* We've probably entered recovery and the peer still has some
1582 * of the data we've sent. Update snd_nxt and accept the ack */
1583 if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1585 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1589 *error = TCP_ERROR_ACK_FUTURE;
1590 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1591 vnet_buffer (b)->tcp.ack_number);
1595 /* If old ACK, probably it's an old dupack */
1596 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1598 *error = TCP_ERROR_ACK_OLD;
1599 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1600 vnet_buffer (b)->tcp.ack_number);
1601 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1602 tcp_cc_handle_event (tc, 1);
1603 /* Don't drop yet */
1610 * Looks okay, process feedback
1612 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1613 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1615 prev_snd_wnd = tc->snd_wnd;
1616 prev_snd_una = tc->snd_una;
1617 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1618 vnet_buffer (b)->tcp.ack_number,
1619 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1620 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1621 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1622 tcp_validate_txf_size (tc, tc->bytes_acked);
1624 if (tc->bytes_acked)
1626 tcp_program_dequeue (wrk, tc);
1627 tcp_update_rtt (tc, vnet_buffer (b)->tcp.ack_number);
1630 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1633 * Check if we have congestion event
1636 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1638 tcp_cc_handle_event (tc, is_dack);
1639 if (!tcp_in_cong_recovery (tc))
1641 *error = TCP_ERROR_ACK_OK;
1644 *error = TCP_ERROR_ACK_DUP;
1645 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1651 * Update congestion control (slow start/congestion avoidance)
1653 tcp_cc_update (tc, b);
1654 *error = TCP_ERROR_ACK_OK;
1659 tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1661 if (!tcp_disconnect_pending (tc))
1663 vec_add1 (wrk->pending_disconnects, tc->c_c_index);
1664 tcp_disconnect_pending_on (tc);
1669 tcp_handle_disconnects (tcp_worker_ctx_t * wrk)
1671 u32 thread_index, *pending_disconnects;
1672 tcp_connection_t *tc;
1675 if (!vec_len (wrk->pending_disconnects))
1678 thread_index = wrk->vm->thread_index;
1679 pending_disconnects = wrk->pending_disconnects;
1680 for (i = 0; i < vec_len (pending_disconnects); i++)
1682 tc = tcp_connection_get (pending_disconnects[i], thread_index);
1683 tcp_disconnect_pending_off (tc);
1684 session_transport_closing_notify (&tc->connection);
1686 _vec_len (wrk->pending_disconnects) = 0;
1690 tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1693 /* Account for the FIN and send ack */
1695 tcp_program_ack (wrk, tc);
1696 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1697 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1698 tcp_connection_set_state (tc, TCP_STATE_CLOSE_WAIT);
1699 tcp_program_disconnect (wrk, tc);
1700 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1701 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc);
1702 *error = TCP_ERROR_FIN_RCVD;
1705 #ifndef CLIB_MARCH_VARIANT
1707 tcp_sack_vector_is_sane (sack_block_t * sacks)
1710 for (i = 1; i < vec_len (sacks); i++)
1712 if (sacks[i - 1].end == sacks[i].start)
1719 * Build SACK list as per RFC2018.
1721 * Makes sure the first block contains the segment that generated the current
1722 * ACK and the following ones are the ones most recently reported in SACK
1725 * @param tc TCP connection for which the SACK list is updated
1726 * @param start Start sequence number of the newest SACK block
1727 * @param end End sequence of the newest SACK block
1730 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1732 sack_block_t *new_list = tc->snd_sacks_fl, *block = 0;
1735 /* If the first segment is ooo add it to the list. Last write might've moved
1736 * rcv_nxt over the first segment. */
1737 if (seq_lt (tc->rcv_nxt, start))
1739 vec_add2 (new_list, block, 1);
1740 block->start = start;
1744 /* Find the blocks still worth keeping. */
1745 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1747 /* Discard if rcv_nxt advanced beyond current block */
1748 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1751 /* Merge or drop if segment overlapped by the new segment */
1752 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1753 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1755 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1756 new_list[0].start = tc->snd_sacks[i].start;
1757 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1758 new_list[0].end = tc->snd_sacks[i].end;
1762 /* Save to new SACK list if we have space. */
1763 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1764 vec_add1 (new_list, tc->snd_sacks[i]);
1767 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1769 /* Replace old vector with new one */
1770 vec_reset_length (tc->snd_sacks);
1771 tc->snd_sacks_fl = tc->snd_sacks;
1772 tc->snd_sacks = new_list;
1774 /* Segments should not 'touch' */
1775 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1779 tcp_sack_list_bytes (tcp_connection_t * tc)
1782 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1783 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1786 #endif /* CLIB_MARCH_VARIANT */
1788 /** Enqueue data for delivery to application */
1790 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1793 int written, error = TCP_ERROR_ENQUEUED;
1795 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1797 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1798 1 /* queue event */ , 1);
1800 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1802 /* Update rcv_nxt */
1803 if (PREDICT_TRUE (written == data_len))
1805 tc->rcv_nxt += written;
1807 /* If more data written than expected, account for out-of-order bytes. */
1808 else if (written > data_len)
1810 tc->rcv_nxt += written;
1811 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1813 else if (written > 0)
1815 /* We've written something but FIFO is probably full now */
1816 tc->rcv_nxt += written;
1817 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1821 return TCP_ERROR_FIFO_FULL;
1824 /* Update SACK list if need be */
1825 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1827 /* Remove SACK blocks that have been delivered */
1828 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1834 /** Enqueue out-of-order data */
1836 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1842 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1845 /* Enqueue out-of-order data with relative offset */
1846 rv = session_enqueue_stream_connection (&tc->connection, b,
1847 vnet_buffer (b)->tcp.seq_number -
1848 tc->rcv_nxt, 0 /* queue event */ ,
1851 /* Nothing written */
1854 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1855 return TCP_ERROR_FIFO_FULL;
1858 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1860 /* Update SACK list if in use */
1861 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1863 ooo_segment_t *newest;
1866 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1868 /* Get the newest segment from the fifo */
1869 newest = svm_fifo_newest_ooo_segment (s0->rx_fifo);
1872 offset = ooo_segment_offset (s0->rx_fifo, newest);
1873 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1874 start = tc->rcv_nxt + offset;
1875 end = start + ooo_segment_length (s0->rx_fifo, newest);
1876 tcp_update_sack_list (tc, start, end);
1877 svm_fifo_newest_ooo_segment_reset (s0->rx_fifo);
1878 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1882 return TCP_ERROR_ENQUEUED_OOO;
1886 * Check if ACK could be delayed. If ack can be delayed, it should return
1887 * true for a full frame. If we're always acking return 0.
1890 tcp_can_delack (tcp_connection_t * tc)
1892 /* Send ack if ... */
1894 /* just sent a rcv wnd 0
1895 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0 */
1896 /* constrained to send ack */
1897 || (tc->flags & TCP_CONN_SNDACK) != 0
1898 /* we're almost out of tx wnd */
1899 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1906 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1908 u32 discard, first = b->current_length;
1909 vlib_main_t *vm = vlib_get_main ();
1911 /* Handle multi-buffer segments */
1912 if (n_bytes_to_drop > b->current_length)
1914 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1918 discard = clib_min (n_bytes_to_drop, b->current_length);
1919 vlib_buffer_advance (b, discard);
1920 b = vlib_get_buffer (vm, b->next_buffer);
1921 n_bytes_to_drop -= discard;
1923 while (n_bytes_to_drop);
1924 if (n_bytes_to_drop > first)
1925 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1928 vlib_buffer_advance (b, n_bytes_to_drop);
1929 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1934 * Receive buffer for connection and handle acks
1936 * It handles both in order or out-of-order data.
1939 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1942 u32 error, n_bytes_to_drop, n_data_bytes;
1944 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1945 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1946 ASSERT (n_data_bytes);
1948 /* Handle out-of-order data */
1949 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1951 /* Old sequence numbers allowed through because they overlapped
1953 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1955 /* Completely in the past (possible retransmit). Ack
1956 * retransmissions since we may not have any data to send */
1957 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1959 tcp_program_ack (wrk, tc);
1960 error = TCP_ERROR_SEGMENT_OLD;
1964 /* Chop off the bytes in the past and see if what is left
1965 * can be enqueued in order */
1966 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1967 n_data_bytes -= n_bytes_to_drop;
1968 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1969 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1971 error = TCP_ERROR_SEGMENT_OLD;
1977 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1978 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1979 tcp_program_dupack (wrk, tc);
1980 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1986 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1987 * segments can be enqueued after fifo tail offset changes. */
1988 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1989 if (tcp_can_delack (tc))
1991 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1992 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1996 tcp_program_ack (wrk, tc);
2004 tcp_header_t tcp_header;
2005 tcp_connection_t tcp_connection;
2009 format_tcp_rx_trace (u8 * s, va_list * args)
2011 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2012 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2013 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2014 u32 indent = format_get_indent (s);
2016 s = format (s, "%U\n%U%U",
2017 format_tcp_header, &t->tcp_header, 128,
2018 format_white_space, indent,
2019 format_tcp_connection, &t->tcp_connection, 1);
2025 format_tcp_rx_trace_short (u8 * s, va_list * args)
2027 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
2028 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
2029 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
2031 s = format (s, "%d -> %d (%U)",
2032 clib_net_to_host_u16 (t->tcp_header.dst_port),
2033 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
2034 t->tcp_connection.state);
2040 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
2041 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
2045 clib_memcpy_fast (&t0->tcp_connection, tc0,
2046 sizeof (t0->tcp_connection));
2050 th0 = tcp_buffer_hdr (b0);
2052 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2056 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2057 vlib_frame_t * frame, u8 is_ip4)
2061 n_left = frame->n_vectors;
2062 from = vlib_frame_vector_args (frame);
2066 tcp_connection_t *tc0;
2073 b0 = vlib_get_buffer (vm, bi0);
2075 if (b0->flags & VLIB_BUFFER_IS_TRACED)
2077 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2078 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2080 th0 = tcp_buffer_hdr (b0);
2081 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
2090 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
2091 u8 is_ip4, u32 evt, u32 val)
2094 vlib_node_increment_counter (vm, tcp4_node, evt, val);
2096 vlib_node_increment_counter (vm, tcp6_node, evt, val);
2099 #define tcp_maybe_inc_counter(node_id, err, count) \
2101 if (next0 != tcp_next_drop (is_ip4)) \
2102 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2103 tcp6_##node_id##_node.index, is_ip4, err, \
2106 #define tcp_inc_counter(node_id, err, count) \
2107 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
2108 tcp6_##node_id##_node.index, is_ip4, \
2110 #define tcp_maybe_inc_err_counter(cnts, err) \
2112 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
2114 #define tcp_inc_err_counter(cnts, err, val) \
2118 #define tcp_store_err_counters(node_id, cnts) \
2121 for (i = 0; i < TCP_N_ERROR; i++) \
2123 tcp_inc_counter(node_id, i, cnts[i]); \
2128 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2129 vlib_frame_t * frame, int is_ip4)
2131 u32 thread_index = vm->thread_index, errors = 0;
2132 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2133 u32 n_left_from, *from, *first_buffer;
2134 u16 err_counters[TCP_N_ERROR] = { 0 };
2136 if (node->flags & VLIB_NODE_FLAG_TRACE)
2137 tcp_established_trace_frame (vm, node, frame, is_ip4);
2139 first_buffer = from = vlib_frame_vector_args (frame);
2140 n_left_from = frame->n_vectors;
2142 while (n_left_from > 0)
2144 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2147 tcp_connection_t *tc0;
2149 if (n_left_from > 1)
2152 pb = vlib_get_buffer (vm, from[1]);
2153 vlib_prefetch_buffer_header (pb, LOAD);
2154 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2161 b0 = vlib_get_buffer (vm, bi0);
2162 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2165 if (PREDICT_FALSE (tc0 == 0))
2167 error0 = TCP_ERROR_INVALID_CONNECTION;
2171 th0 = tcp_buffer_hdr (b0);
2173 /* TODO header prediction fast path */
2175 /* 1-4: check SEQ, RST, SYN */
2176 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2178 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2182 /* 5: check the ACK field */
2183 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2186 /* 6: check the URG bit TODO */
2188 /* 7: process the segment text */
2189 if (vnet_buffer (b0)->tcp.data_len)
2190 error0 = tcp_segment_rcv (wrk, tc0, b0);
2192 /* 8: check the FIN bit */
2193 if (PREDICT_FALSE (tcp_is_fin (th0)))
2194 tcp_rcv_fin (wrk, tc0, b0, &error0);
2197 tcp_inc_err_counter (err_counters, error0, 1);
2200 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2202 err_counters[TCP_ERROR_MSG_QUEUE_FULL] = errors;
2203 tcp_store_err_counters (established, err_counters);
2204 tcp_handle_postponed_dequeues (wrk);
2205 tcp_handle_disconnects (wrk);
2206 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2208 return frame->n_vectors;
2211 VLIB_NODE_FN (tcp4_established_node) (vlib_main_t * vm,
2212 vlib_node_runtime_t * node,
2213 vlib_frame_t * from_frame)
2215 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2218 VLIB_NODE_FN (tcp6_established_node) (vlib_main_t * vm,
2219 vlib_node_runtime_t * node,
2220 vlib_frame_t * from_frame)
2222 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2226 VLIB_REGISTER_NODE (tcp4_established_node) =
2228 .name = "tcp4-established",
2229 /* Takes a vector of packets. */
2230 .vector_size = sizeof (u32),
2231 .n_errors = TCP_N_ERROR,
2232 .error_strings = tcp_error_strings,
2233 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2236 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2237 foreach_tcp_state_next
2240 .format_trace = format_tcp_rx_trace_short,
2245 VLIB_REGISTER_NODE (tcp6_established_node) =
2247 .name = "tcp6-established",
2248 /* Takes a vector of packets. */
2249 .vector_size = sizeof (u32),
2250 .n_errors = TCP_N_ERROR,
2251 .error_strings = tcp_error_strings,
2252 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2255 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2256 foreach_tcp_state_next
2259 .format_trace = format_tcp_rx_trace_short,
2265 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2267 transport_connection_t *tmp = 0;
2274 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2277 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2278 && (tc->state == TCP_STATE_LISTEN
2279 || tc->c_rmt_port == hdr->src_port));
2283 handle = session_lookup_half_open_handle (&tc->connection);
2284 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2285 tc->c_proto, tc->c_is_ip4);
2289 if (tmp->lcl_port == hdr->dst_port
2290 && tmp->rmt_port == hdr->src_port)
2292 TCP_DBG ("half-open is valid!");
2300 * Lookup transport connection
2302 static tcp_connection_t *
2303 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2307 transport_connection_t *tconn;
2308 tcp_connection_t *tc;
2313 ip4 = vlib_buffer_get_current (b);
2314 tcp = ip4_next_header (ip4);
2315 tconn = session_lookup_connection_wt4 (fib_index,
2320 TRANSPORT_PROTO_TCP,
2321 thread_index, &is_filtered);
2322 tc = tcp_get_connection_from_transport (tconn);
2323 ASSERT (tcp_lookup_is_valid (tc, tcp));
2328 ip6 = vlib_buffer_get_current (b);
2329 tcp = ip6_next_header (ip6);
2330 tconn = session_lookup_connection_wt6 (fib_index,
2335 TRANSPORT_PROTO_TCP,
2336 thread_index, &is_filtered);
2337 tc = tcp_get_connection_from_transport (tconn);
2338 ASSERT (tcp_lookup_is_valid (tc, tcp));
2344 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2345 vlib_frame_t * from_frame, int is_ip4)
2347 tcp_main_t *tm = vnet_get_tcp_main ();
2348 u32 n_left_from, *from, *first_buffer, errors = 0;
2349 u32 my_thread_index = vm->thread_index;
2350 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2352 from = first_buffer = vlib_frame_vector_args (from_frame);
2353 n_left_from = from_frame->n_vectors;
2355 while (n_left_from > 0)
2357 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2358 tcp_connection_t *tc0, *new_tc0;
2359 tcp_header_t *tcp0 = 0;
2367 b0 = vlib_get_buffer (vm, bi0);
2369 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2370 if (PREDICT_FALSE (tc0 == 0))
2372 error0 = TCP_ERROR_INVALID_CONNECTION;
2376 /* Half-open completed recently but the connection was't removed
2377 * yet by the owning thread */
2378 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2380 /* Make sure the connection actually exists */
2381 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2382 my_thread_index, is_ip4));
2383 error0 = TCP_ERROR_SPURIOUS_SYN_ACK;
2387 ack0 = vnet_buffer (b0)->tcp.ack_number;
2388 seq0 = vnet_buffer (b0)->tcp.seq_number;
2389 tcp0 = tcp_buffer_hdr (b0);
2391 /* Crude check to see if the connection handle does not match
2392 * the packet. Probably connection just switched to established */
2393 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2394 || tcp0->src_port != tc0->c_rmt_port))
2396 error0 = TCP_ERROR_INVALID_CONNECTION;
2400 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2401 && !tcp_syn (tcp0)))
2403 error0 = TCP_ERROR_SEGMENT_INVALID;
2407 /* SYNs consume sequence numbers */
2408 vnet_buffer (b0)->tcp.seq_end += tcp_is_syn (tcp0);
2411 * 1. check the ACK bit
2415 * If the ACK bit is set
2416 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2417 * the RST bit is set, if so drop the segment and return)
2418 * <SEQ=SEG.ACK><CTL=RST>
2419 * and discard the segment. Return.
2420 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2424 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2426 if (!tcp_rst (tcp0))
2427 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2428 error0 = TCP_ERROR_RCV_WND;
2432 /* Make sure ACK is valid */
2433 if (seq_gt (tc0->snd_una, ack0))
2435 error0 = TCP_ERROR_ACK_INVALID;
2441 * 2. check the RST bit
2446 /* If ACK is acceptable, signal client that peer is not
2447 * willing to accept connection and drop connection*/
2449 tcp_connection_reset (tc0);
2450 error0 = TCP_ERROR_RST_RCVD;
2455 * 3. check the security and precedence (skipped)
2459 * 4. check the SYN bit
2462 /* No SYN flag. Drop. */
2463 if (!tcp_syn (tcp0))
2465 error0 = TCP_ERROR_SEGMENT_INVALID;
2470 if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1))
2472 error0 = TCP_ERROR_OPTIONS;
2476 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2477 * current thread pool. */
2478 pool_get (tm->connections[my_thread_index], new_tc0);
2479 clib_memcpy_fast (new_tc0, tc0, sizeof (*new_tc0));
2480 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2481 new_tc0->c_thread_index = my_thread_index;
2482 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2483 new_tc0->irs = seq0;
2484 new_tc0->timers[TCP_TIMER_ESTABLISH_AO] = TCP_TIMER_HANDLE_INVALID;
2485 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2486 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2488 /* If this is not the owning thread, wait for syn retransmit to
2489 * expire and cleanup then */
2490 if (tcp_half_open_connection_cleanup (tc0))
2491 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2493 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2495 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2496 new_tc0->tsval_recent_age = tcp_time_now ();
2499 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2500 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2502 new_tc0->rcv_wscale = 0;
2504 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2505 << new_tc0->snd_wscale;
2506 new_tc0->snd_wl1 = seq0;
2507 new_tc0->snd_wl2 = ack0;
2509 tcp_connection_init_vars (new_tc0);
2511 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2512 if (PREDICT_TRUE (tcp_ack (tcp0)))
2514 /* Our SYN is ACKed: we have iss < ack = snd_una */
2516 /* TODO Dequeue acknowledged segments if we support Fast Open */
2517 new_tc0->snd_una = ack0;
2518 new_tc0->state = TCP_STATE_ESTABLISHED;
2520 /* Make sure las is initialized for the wnd computation */
2521 new_tc0->rcv_las = new_tc0->rcv_nxt;
2523 /* Notify app that we have connection. If session layer can't
2524 * allocate session send reset */
2525 if (session_stream_connect_notify (&new_tc0->connection, 0))
2527 clib_warning ("connect notify fail");
2528 tcp_send_reset_w_pkt (new_tc0, b0, my_thread_index, is_ip4);
2529 tcp_connection_cleanup (new_tc0);
2533 new_tc0->tx_fifo_size =
2534 transport_tx_fifo_size (&new_tc0->connection);
2535 /* Update rtt with the syn-ack sample */
2536 tcp_estimate_initial_rtt (new_tc0);
2537 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2538 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2540 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2543 new_tc0->state = TCP_STATE_SYN_RCVD;
2545 /* Notify app that we have connection */
2546 if (session_stream_connect_notify (&new_tc0->connection, 0))
2548 tcp_connection_cleanup (new_tc0);
2549 tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4);
2550 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2554 new_tc0->tx_fifo_size =
2555 transport_tx_fifo_size (&new_tc0->connection);
2556 new_tc0->rtt_ts = 0;
2557 tcp_init_snd_vars (new_tc0);
2558 tcp_send_synack (new_tc0);
2559 error0 = TCP_ERROR_SYNS_RCVD;
2563 /* Read data, if any */
2564 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2566 clib_warning ("rcvd data in syn-sent");
2567 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2568 if (error0 == TCP_ERROR_ACK_OK)
2569 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2573 tcp_program_ack (wrk, new_tc0);
2578 tcp_inc_counter (syn_sent, error0, 1);
2579 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2581 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2582 clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2583 clib_memcpy_fast (&t0->tcp_connection, tc0,
2584 sizeof (t0->tcp_connection));
2588 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2590 tcp_inc_counter (syn_sent, TCP_ERROR_MSG_QUEUE_FULL, errors);
2591 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2593 return from_frame->n_vectors;
2596 VLIB_NODE_FN (tcp4_syn_sent_node) (vlib_main_t * vm,
2597 vlib_node_runtime_t * node,
2598 vlib_frame_t * from_frame)
2600 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2603 VLIB_NODE_FN (tcp6_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, 0 /* is_ip4 */ );
2611 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2613 .name = "tcp4-syn-sent",
2614 /* Takes a vector of packets. */
2615 .vector_size = sizeof (u32),
2616 .n_errors = TCP_N_ERROR,
2617 .error_strings = tcp_error_strings,
2618 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2621 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2622 foreach_tcp_state_next
2625 .format_trace = format_tcp_rx_trace_short,
2630 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2632 .name = "tcp6-syn-sent",
2633 /* Takes a vector of packets. */
2634 .vector_size = sizeof (u32),
2635 .n_errors = TCP_N_ERROR,
2636 .error_strings = tcp_error_strings,
2637 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2640 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2641 foreach_tcp_state_next
2644 .format_trace = format_tcp_rx_trace_short,
2649 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2650 * as per RFC793 p. 64
2653 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2654 vlib_frame_t * from_frame, int is_ip4)
2656 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2657 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2658 u32 n_left_from, *from, max_dequeue;
2660 from = first_buffer = vlib_frame_vector_args (from_frame);
2661 n_left_from = from_frame->n_vectors;
2663 while (n_left_from > 0)
2665 u32 bi0, error0 = TCP_ERROR_NONE;
2666 tcp_header_t *tcp0 = 0;
2667 tcp_connection_t *tc0;
2675 b0 = vlib_get_buffer (vm, bi0);
2676 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2678 if (PREDICT_FALSE (tc0 == 0))
2680 error0 = TCP_ERROR_INVALID_CONNECTION;
2684 tcp0 = tcp_buffer_hdr (b0);
2685 is_fin0 = tcp_is_fin (tcp0);
2689 tcp_connection_t *tmp;
2690 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2692 if (tmp->state != tc0->state)
2694 if (tc0->state != TCP_STATE_CLOSED)
2695 clib_warning ("state changed");
2701 * Special treatment for CLOSED
2703 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2705 error0 = TCP_ERROR_CONNECTION_CLOSED;
2710 * For all other states (except LISTEN)
2713 /* 1-4: check SEQ, RST, SYN */
2714 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2717 /* 5: check the ACK field */
2720 case TCP_STATE_SYN_RCVD:
2722 /* Make sure the segment is exactly right */
2723 if (tc0->rcv_nxt != vnet_buffer (b0)->tcp.seq_number || is_fin0)
2725 tcp_connection_reset (tc0);
2726 error0 = TCP_ERROR_SEGMENT_INVALID;
2731 * If the segment acknowledgment is not acceptable, form a
2733 * <SEQ=SEG.ACK><CTL=RST>
2736 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2738 tcp_connection_reset (tc0);
2742 /* Update rtt and rto */
2743 tcp_estimate_initial_rtt (tc0);
2745 /* Switch state to ESTABLISHED */
2746 tc0->state = TCP_STATE_ESTABLISHED;
2747 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2749 /* Initialize session variables */
2750 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2751 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2752 << tc0->rcv_opts.wscale;
2753 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2754 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2756 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2757 tcp_retransmit_timer_reset (tc0);
2758 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2759 if (session_stream_accept_notify (&tc0->connection))
2761 error0 = TCP_ERROR_MSG_QUEUE_FULL;
2762 tcp_connection_reset (tc0);
2765 error0 = TCP_ERROR_ACK_OK;
2767 case TCP_STATE_ESTABLISHED:
2768 /* We can get packets in established state here because they
2769 * were enqueued before state change */
2770 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2774 case TCP_STATE_FIN_WAIT_1:
2775 /* In addition to the processing for the ESTABLISHED state, if
2776 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2777 * continue processing in that state. */
2778 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2781 /* Still have to send the FIN */
2782 if (tc0->flags & TCP_CONN_FINPNDG)
2784 /* TX fifo finally drained */
2785 max_dequeue = transport_max_tx_dequeue (&tc0->connection);
2786 if (max_dequeue <= tc0->burst_acked)
2789 /* If FIN is ACKed */
2790 else if (tc0->snd_una == tc0->snd_nxt)
2792 /* Stop all retransmit timers because we have nothing more
2794 tcp_connection_timers_reset (tc0);
2796 /* We already have a FIN but didn't transition to CLOSING
2797 * because of outstanding tx data. Close the connection. */
2798 if (tc0->flags & TCP_CONN_FINRCVD)
2800 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2801 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2805 tcp_connection_set_state (tc0, TCP_STATE_FIN_WAIT_2);
2806 /* Enable waitclose because we're willing to wait for peer's
2807 * FIN but not indefinitely. */
2808 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2810 /* Don't try to deq the FIN acked */
2811 if (tc0->burst_acked > 1)
2812 session_tx_fifo_dequeue_drop (&tc0->connection,
2813 tc0->burst_acked - 1);
2814 tc0->burst_acked = 0;
2817 case TCP_STATE_FIN_WAIT_2:
2818 /* In addition to the processing for the ESTABLISHED state, if
2819 * the retransmission queue is empty, the user's CLOSE can be
2820 * acknowledged ("ok") but do not delete the TCB. */
2821 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2823 tc0->burst_acked = 0;
2825 case TCP_STATE_CLOSE_WAIT:
2826 /* Do the same processing as for the ESTABLISHED state. */
2827 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2830 if (!(tc0->flags & TCP_CONN_FINPNDG))
2833 /* Still have outstanding tx data */
2834 if (transport_max_tx_dequeue (&tc0->connection))
2838 tcp_connection_timers_reset (tc0);
2839 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2840 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2842 case TCP_STATE_CLOSING:
2843 /* In addition to the processing for the ESTABLISHED state, if
2844 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2845 * otherwise ignore the segment. */
2846 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2849 if (tc0->snd_una != tc0->snd_nxt)
2852 tcp_connection_timers_reset (tc0);
2853 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2854 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2858 case TCP_STATE_LAST_ACK:
2859 /* The only thing that [should] arrive in this state is an
2860 * acknowledgment of our FIN. If our FIN is now acknowledged,
2861 * delete the TCB, enter the CLOSED state, and return. */
2863 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2866 /* Apparently our ACK for the peer's FIN was lost */
2867 if (is_fin0 && tc0->snd_una != tc0->snd_nxt)
2873 tcp_connection_set_state (tc0, TCP_STATE_CLOSED);
2875 /* Don't free the connection from the data path since
2876 * we can't ensure that we have no packets already enqueued
2877 * to output. Rely instead on the waitclose timer */
2878 tcp_connection_timers_reset (tc0);
2879 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2884 case TCP_STATE_TIME_WAIT:
2885 /* The only thing that can arrive in this state is a
2886 * retransmission of the remote FIN. Acknowledge it, and restart
2887 * the 2 MSL timeout. */
2889 if (tcp_rcv_ack_no_cc (tc0, b0, &error0))
2895 tcp_program_ack (wrk, tc0);
2896 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2904 /* 6: check the URG bit TODO */
2906 /* 7: process the segment text */
2909 case TCP_STATE_ESTABLISHED:
2910 case TCP_STATE_FIN_WAIT_1:
2911 case TCP_STATE_FIN_WAIT_2:
2912 if (vnet_buffer (b0)->tcp.data_len)
2913 error0 = tcp_segment_rcv (wrk, tc0, b0);
2915 case TCP_STATE_CLOSE_WAIT:
2916 case TCP_STATE_CLOSING:
2917 case TCP_STATE_LAST_ACK:
2918 case TCP_STATE_TIME_WAIT:
2919 /* This should not occur, since a FIN has been received from the
2920 * remote side. Ignore the segment text. */
2924 /* 8: check the FIN bit */
2928 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2932 case TCP_STATE_ESTABLISHED:
2933 /* Account for the FIN and send ack */
2935 tcp_program_ack (wrk, tc0);
2936 tcp_connection_set_state (tc0, TCP_STATE_CLOSE_WAIT);
2937 tcp_program_disconnect (wrk, tc0);
2938 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
2940 case TCP_STATE_SYN_RCVD:
2941 /* Send FIN-ACK, enter LAST-ACK and because the app was not
2942 * notified yet, set a cleanup timer instead of relying on
2943 * disconnect notify and the implicit close call. */
2944 tcp_connection_timers_reset (tc0);
2947 tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK);
2948 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2950 case TCP_STATE_CLOSE_WAIT:
2951 case TCP_STATE_CLOSING:
2952 case TCP_STATE_LAST_ACK:
2955 case TCP_STATE_FIN_WAIT_1:
2957 /* If data is outstanding stay in FIN_WAIT_1 and try to finish
2959 if (tc0->flags & TCP_CONN_FINPNDG)
2961 tc0->flags |= TCP_CONN_FINRCVD;
2965 tcp_connection_set_state (tc0, TCP_STATE_CLOSING);
2966 tcp_program_ack (wrk, tc0);
2968 /* Wait for ACK for our FIN but not forever */
2969 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2971 case TCP_STATE_FIN_WAIT_2:
2972 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2974 tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
2975 tcp_connection_timers_reset (tc0);
2976 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2977 tcp_program_ack (wrk, tc0);
2979 case TCP_STATE_TIME_WAIT:
2980 /* Remain in the TIME-WAIT state. Restart the time-wait
2983 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2986 error0 = TCP_ERROR_FIN_RCVD;
2990 tcp_inc_counter (rcv_process, error0, 1);
2991 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2993 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2994 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2998 errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP,
3000 tcp_inc_counter (rcv_process, TCP_ERROR_MSG_QUEUE_FULL, errors);
3001 tcp_handle_postponed_dequeues (wrk);
3002 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3004 return from_frame->n_vectors;
3007 VLIB_NODE_FN (tcp4_rcv_process_node) (vlib_main_t * vm,
3008 vlib_node_runtime_t * node,
3009 vlib_frame_t * from_frame)
3011 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3014 VLIB_NODE_FN (tcp6_rcv_process_node) (vlib_main_t * vm,
3015 vlib_node_runtime_t * node,
3016 vlib_frame_t * from_frame)
3018 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3022 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
3024 .name = "tcp4-rcv-process",
3025 /* Takes a vector of packets. */
3026 .vector_size = sizeof (u32),
3027 .n_errors = TCP_N_ERROR,
3028 .error_strings = tcp_error_strings,
3029 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3032 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3033 foreach_tcp_state_next
3036 .format_trace = format_tcp_rx_trace_short,
3041 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
3043 .name = "tcp6-rcv-process",
3044 /* Takes a vector of packets. */
3045 .vector_size = sizeof (u32),
3046 .n_errors = TCP_N_ERROR,
3047 .error_strings = tcp_error_strings,
3048 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
3051 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
3052 foreach_tcp_state_next
3055 .format_trace = format_tcp_rx_trace_short,
3060 * LISTEN state processing as per RFC 793 p. 65
3063 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3064 vlib_frame_t * from_frame, int is_ip4)
3066 u32 n_left_from, *from, n_syns = 0, *first_buffer;
3067 u32 my_thread_index = vm->thread_index;
3069 from = first_buffer = vlib_frame_vector_args (from_frame);
3070 n_left_from = from_frame->n_vectors;
3072 while (n_left_from > 0)
3077 tcp_header_t *th0 = 0;
3078 tcp_connection_t *lc0;
3081 tcp_connection_t *child0;
3082 u32 error0 = TCP_ERROR_NONE;
3088 b0 = vlib_get_buffer (vm, bi0);
3089 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
3093 ip40 = vlib_buffer_get_current (b0);
3094 th0 = ip4_next_header (ip40);
3098 ip60 = vlib_buffer_get_current (b0);
3099 th0 = ip6_next_header (ip60);
3102 /* Create child session. For syn-flood protection use filter */
3104 /* 1. first check for an RST: handled in dispatch */
3105 /* if (tcp_rst (th0))
3109 /* 2. second check for an ACK: handled in dispatch */
3110 /* if (tcp_ack (th0))
3112 tcp_send_reset (b0, is_ip4);
3117 /* 3. check for a SYN (did that already) */
3119 /* Make sure connection wasn't just created */
3120 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
3122 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
3124 error0 = TCP_ERROR_CREATE_EXISTS;
3128 /* Create child session and send SYN-ACK */
3129 child0 = tcp_connection_alloc (my_thread_index);
3130 child0->c_lcl_port = th0->dst_port;
3131 child0->c_rmt_port = th0->src_port;
3132 child0->c_is_ip4 = is_ip4;
3133 child0->state = TCP_STATE_SYN_RCVD;
3134 child0->c_fib_index = lc0->c_fib_index;
3138 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3139 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3143 clib_memcpy_fast (&child0->c_lcl_ip6, &ip60->dst_address,
3144 sizeof (ip6_address_t));
3145 clib_memcpy_fast (&child0->c_rmt_ip6, &ip60->src_address,
3146 sizeof (ip6_address_t));
3149 if (tcp_options_parse (th0, &child0->rcv_opts, 1))
3151 error0 = TCP_ERROR_OPTIONS;
3152 tcp_connection_free (child0);
3156 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3157 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3158 child0->rcv_las = child0->rcv_nxt;
3159 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3161 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3162 * segments are used to initialize PAWS. */
3163 if (tcp_opts_tstamp (&child0->rcv_opts))
3165 child0->tsval_recent = child0->rcv_opts.tsval;
3166 child0->tsval_recent_age = tcp_time_now ();
3169 if (tcp_opts_wscale (&child0->rcv_opts))
3170 child0->snd_wscale = child0->rcv_opts.wscale;
3172 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3173 << child0->snd_wscale;
3174 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3175 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3177 tcp_connection_init_vars (child0);
3178 child0->rto = TCP_RTO_MIN;
3179 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
3181 if (session_stream_accept (&child0->connection, lc0->c_s_index,
3184 tcp_connection_cleanup (child0);
3185 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3189 child0->tx_fifo_size = transport_tx_fifo_size (&child0->connection);
3190 tcp_send_synack (child0);
3191 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
3195 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3197 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3198 clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3199 clib_memcpy_fast (&t0->tcp_connection, lc0,
3200 sizeof (t0->tcp_connection));
3203 n_syns += (error0 == TCP_ERROR_NONE);
3206 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3207 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3209 return from_frame->n_vectors;
3212 VLIB_NODE_FN (tcp4_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3213 vlib_frame_t * from_frame)
3215 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3218 VLIB_NODE_FN (tcp6_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3219 vlib_frame_t * from_frame)
3221 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3225 VLIB_REGISTER_NODE (tcp4_listen_node) =
3227 .name = "tcp4-listen",
3228 /* Takes a vector of packets. */
3229 .vector_size = sizeof (u32),
3230 .n_errors = TCP_N_ERROR,
3231 .error_strings = tcp_error_strings,
3232 .n_next_nodes = TCP_LISTEN_N_NEXT,
3235 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3236 foreach_tcp_state_next
3239 .format_trace = format_tcp_rx_trace_short,
3244 VLIB_REGISTER_NODE (tcp6_listen_node) =
3246 .name = "tcp6-listen",
3247 /* Takes a vector of packets. */
3248 .vector_size = sizeof (u32),
3249 .n_errors = TCP_N_ERROR,
3250 .error_strings = tcp_error_strings,
3251 .n_next_nodes = TCP_LISTEN_N_NEXT,
3254 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3255 foreach_tcp_state_next
3258 .format_trace = format_tcp_rx_trace_short,
3262 typedef enum _tcp_input_next
3264 TCP_INPUT_NEXT_DROP,
3265 TCP_INPUT_NEXT_LISTEN,
3266 TCP_INPUT_NEXT_RCV_PROCESS,
3267 TCP_INPUT_NEXT_SYN_SENT,
3268 TCP_INPUT_NEXT_ESTABLISHED,
3269 TCP_INPUT_NEXT_RESET,
3270 TCP_INPUT_NEXT_PUNT,
3274 #define foreach_tcp4_input_next \
3275 _ (DROP, "ip4-drop") \
3276 _ (LISTEN, "tcp4-listen") \
3277 _ (RCV_PROCESS, "tcp4-rcv-process") \
3278 _ (SYN_SENT, "tcp4-syn-sent") \
3279 _ (ESTABLISHED, "tcp4-established") \
3280 _ (RESET, "tcp4-reset") \
3281 _ (PUNT, "ip4-punt")
3283 #define foreach_tcp6_input_next \
3284 _ (DROP, "ip6-drop") \
3285 _ (LISTEN, "tcp6-listen") \
3286 _ (RCV_PROCESS, "tcp6-rcv-process") \
3287 _ (SYN_SENT, "tcp6-syn-sent") \
3288 _ (ESTABLISHED, "tcp6-established") \
3289 _ (RESET, "tcp6-reset") \
3290 _ (PUNT, "ip6-punt")
3292 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3295 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3296 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3298 tcp_connection_t *tc;
3303 for (i = 0; i < n_bufs; i++)
3305 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3307 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3308 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3310 tcp = vlib_buffer_get_current (bs[i]);
3311 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3317 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3319 if (*error == TCP_ERROR_FILTERED || *error == TCP_ERROR_WRONG_THREAD)
3321 *next = TCP_INPUT_NEXT_DROP;
3323 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3325 *next = TCP_INPUT_NEXT_PUNT;
3326 *error = TCP_ERROR_PUNT;
3330 *next = TCP_INPUT_NEXT_RESET;
3331 *error = TCP_ERROR_NO_LISTENER;
3335 static inline tcp_connection_t *
3336 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3339 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3340 int n_advance_bytes, n_data_bytes;
3341 transport_connection_t *tc;
3347 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3348 int ip_hdr_bytes = ip4_header_bytes (ip4);
3349 if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp)))
3351 *error = TCP_ERROR_LENGTH;
3354 tcp = ip4_next_header (ip4);
3355 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3356 n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp));
3357 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3359 /* Length check. Checksum computed by ipx_local no need to compute again */
3360 if (PREDICT_FALSE (n_data_bytes < 0))
3362 *error = TCP_ERROR_LENGTH;
3366 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3367 &ip4->src_address, tcp->dst_port,
3368 tcp->src_port, TRANSPORT_PROTO_TCP,
3369 thread_index, &result);
3373 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3374 if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp)))
3376 *error = TCP_ERROR_LENGTH;
3379 tcp = ip6_next_header (ip6);
3380 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3381 n_advance_bytes = tcp_header_bytes (tcp);
3382 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3384 n_advance_bytes += sizeof (ip6[0]);
3386 if (PREDICT_FALSE (n_data_bytes < 0))
3388 *error = TCP_ERROR_LENGTH;
3392 (ip6_address_is_link_local_unicast (&ip6->dst_address)))
3394 ip4_main_t *im = &ip4_main;
3395 fib_index = vec_elt (im->fib_index_by_sw_if_index,
3396 vnet_buffer (b)->sw_if_index[VLIB_RX]);
3399 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3400 &ip6->src_address, tcp->dst_port,
3401 tcp->src_port, TRANSPORT_PROTO_TCP,
3402 thread_index, &result);
3405 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3406 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3407 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3408 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3409 vnet_buffer (b)->tcp.seq_end = vnet_buffer (b)->tcp.seq_number
3411 vnet_buffer (b)->tcp.flags = 0;
3413 *error = result ? TCP_ERROR_NONE + result : *error;
3415 return tcp_get_connection_from_transport (tc);
3419 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3420 vlib_buffer_t * b, u16 * next, u32 * error)
3425 tcp = tcp_buffer_hdr (b);
3426 flags = tcp->flags & filter_flags;
3427 *next = tm->dispatch_table[tc->state][flags].next;
3428 *error = tm->dispatch_table[tc->state][flags].error;
3430 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3431 || *next == TCP_INPUT_NEXT_RESET))
3433 /* Overload tcp flags to store state */
3434 tcp_state_t state = tc->state;
3435 vnet_buffer (b)->tcp.flags = tc->state;
3437 if (*error == TCP_ERROR_DISPATCH)
3438 clib_warning ("tcp conn %u disp error state %U flags %U",
3439 tc->c_c_index, format_tcp_state, state,
3440 format_tcp_flags, (int) flags);
3445 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3446 vlib_frame_t * frame, int is_ip4)
3448 u32 n_left_from, *from, thread_index = vm->thread_index;
3449 tcp_main_t *tm = vnet_get_tcp_main ();
3450 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3451 u16 nexts[VLIB_FRAME_SIZE], *next;
3453 tcp_set_time_now (tcp_get_worker (thread_index));
3455 from = vlib_frame_vector_args (frame);
3456 n_left_from = frame->n_vectors;
3457 vlib_get_buffers (vm, from, bufs, n_left_from);
3462 while (n_left_from >= 4)
3464 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3465 tcp_connection_t *tc0, *tc1;
3468 vlib_prefetch_buffer_header (b[2], STORE);
3469 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3471 vlib_prefetch_buffer_header (b[3], STORE);
3472 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3475 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3477 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3478 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4);
3480 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3482 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3483 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3485 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3486 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3488 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3489 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3493 if (PREDICT_TRUE (tc0 != 0))
3495 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3496 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3497 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3500 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3502 if (PREDICT_TRUE (tc1 != 0))
3504 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3505 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3506 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3509 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3516 while (n_left_from > 0)
3518 tcp_connection_t *tc0;
3519 u32 error0 = TCP_ERROR_NO_LISTENER;
3521 if (n_left_from > 1)
3523 vlib_prefetch_buffer_header (b[1], STORE);
3524 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3527 next[0] = TCP_INPUT_NEXT_DROP;
3528 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3529 if (PREDICT_TRUE (tc0 != 0))
3531 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3532 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3533 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3536 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3543 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3544 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3546 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3547 return frame->n_vectors;
3550 VLIB_NODE_FN (tcp4_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3551 vlib_frame_t * from_frame)
3553 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3556 VLIB_NODE_FN (tcp6_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
3557 vlib_frame_t * from_frame)
3559 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3563 VLIB_REGISTER_NODE (tcp4_input_node) =
3565 .name = "tcp4-input",
3566 /* Takes a vector of packets. */
3567 .vector_size = sizeof (u32),
3568 .n_errors = TCP_N_ERROR,
3569 .error_strings = tcp_error_strings,
3570 .n_next_nodes = TCP_INPUT_N_NEXT,
3573 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3574 foreach_tcp4_input_next
3577 .format_buffer = format_tcp_header,
3578 .format_trace = format_tcp_rx_trace,
3583 VLIB_REGISTER_NODE (tcp6_input_node) =
3585 .name = "tcp6-input",
3586 /* Takes a vector of packets. */
3587 .vector_size = sizeof (u32),
3588 .n_errors = TCP_N_ERROR,
3589 .error_strings = tcp_error_strings,
3590 .n_next_nodes = TCP_INPUT_N_NEXT,
3593 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3594 foreach_tcp6_input_next
3597 .format_buffer = format_tcp_header,
3598 .format_trace = format_tcp_rx_trace,
3602 #ifndef CLIB_MARCH_VARIANT
3604 tcp_dispatch_table_init (tcp_main_t * tm)
3607 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3608 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3610 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3611 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3614 #define _(t,f,n,e) \
3616 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3617 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3620 /* RFC 793: In LISTEN if RST drop and if ACK return RST */
3621 _(LISTEN, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3622 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_ACK_INVALID);
3623 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_INVALID_CONNECTION);
3624 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3625 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3626 TCP_ERROR_ACK_INVALID);
3627 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3628 TCP_ERROR_SEGMENT_INVALID);
3629 _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3630 TCP_ERROR_SEGMENT_INVALID);
3631 _(LISTEN, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3632 TCP_ERROR_INVALID_CONNECTION);
3633 _(LISTEN, TCP_FLAG_FIN, TCP_INPUT_NEXT_RESET, TCP_ERROR_SEGMENT_INVALID);
3634 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3635 TCP_ERROR_SEGMENT_INVALID);
3636 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3637 TCP_ERROR_SEGMENT_INVALID);
3638 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3640 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_DROP,
3641 TCP_ERROR_SEGMENT_INVALID);
3642 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3643 TCP_ERROR_SEGMENT_INVALID);
3644 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP,
3645 TCP_ERROR_SEGMENT_INVALID);
3646 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3647 TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3648 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3649 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3650 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3651 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3653 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3654 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3656 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3658 _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3659 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3660 _(SYN_RCVD, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3661 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3663 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3665 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3666 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3667 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3669 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3670 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3671 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3672 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3673 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3674 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3675 _(SYN_RCVD, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3676 /* SYN-ACK for a SYN */
3677 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3679 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3680 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3681 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3683 _(SYN_SENT, TCP_FLAG_FIN, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3684 _(SYN_SENT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3686 /* ACK for for established connection -> tcp-established. */
3687 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3688 /* FIN for for established connection -> tcp-established. */
3689 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3690 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3692 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3694 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3695 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3696 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED,
3698 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3699 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3700 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3701 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3702 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3703 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3704 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3705 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3707 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3708 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3710 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED,
3712 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3713 TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3714 _(ESTABLISHED, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3715 /* ACK or FIN-ACK to our FIN */
3716 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3717 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3719 /* FIN in reply to our FIN from the other side */
3720 _(FIN_WAIT_1, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3721 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3722 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3724 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3725 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3726 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3727 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3728 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3729 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3730 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3732 _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3733 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3734 _(FIN_WAIT_1, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3735 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3737 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3739 _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3740 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3741 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3742 _(FIN_WAIT_1, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3744 _(CLOSING, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3745 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3746 _(CLOSING, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3747 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3749 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3751 _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3752 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3753 _(CLOSING, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3754 _(CLOSING, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3756 _(CLOSING, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3757 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3759 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3761 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3762 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3763 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3765 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3766 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3767 _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3768 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3769 /* FIN confirming that the peer (app) has closed */
3770 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3771 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3772 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3774 _(FIN_WAIT_2, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3775 _(FIN_WAIT_2, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3777 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3778 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3780 _(CLOSE_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3781 _(CLOSE_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3783 _(LAST_ACK, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID);
3784 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3785 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3786 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3788 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS,
3790 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK,
3791 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3792 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3794 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK,
3795 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3796 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST,
3797 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3798 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3799 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3800 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3801 _(LAST_ACK, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3803 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3804 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3806 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS,
3808 _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK,
3809 TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3810 _(TIME_WAIT, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3811 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3812 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3814 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3815 _(TIME_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3817 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3818 /* RFC793 CLOSED: An incoming segment containing a RST is discarded. An
3819 * incoming segment not containing a RST causes a RST to be sent in
3821 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3822 _(CLOSED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3823 TCP_ERROR_CONNECTION_CLOSED);
3824 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3825 _(CLOSED, TCP_FLAG_SYN, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3826 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3831 static clib_error_t *
3832 tcp_input_init (vlib_main_t * vm)
3834 clib_error_t *error = 0;
3835 tcp_main_t *tm = vnet_get_tcp_main ();
3837 if ((error = vlib_call_init_function (vm, tcp_init)))
3840 /* Initialize dispatch table. */
3841 tcp_dispatch_table_init (tm);
3846 VLIB_INIT_FUNCTION (tcp_input_init);
3848 #endif /* CLIB_MARCH_VARIANT */
3851 * fd.io coding-style-patch-verification: ON
3854 * eval: (c-set-style "gnu")