2 * Copyright (c) 2016 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
16 #include <vppinfra/sparse_vec.h>
17 #include <vnet/tcp/tcp_packet.h>
18 #include <vnet/tcp/tcp.h>
19 #include <vnet/session/session.h>
22 static char *tcp_error_strings[] = {
23 #define tcp_error(n,s) s,
24 #include <vnet/tcp/tcp_error.def>
28 /* All TCP nodes have the same outgoing arcs */
29 #define foreach_tcp_state_next \
30 _ (DROP4, "ip4-drop") \
31 _ (DROP6, "ip6-drop") \
32 _ (TCP4_OUTPUT, "tcp4-output") \
33 _ (TCP6_OUTPUT, "tcp6-output")
35 typedef enum _tcp_established_next
37 #define _(s,n) TCP_ESTABLISHED_NEXT_##s,
38 foreach_tcp_state_next
40 TCP_ESTABLISHED_N_NEXT,
41 } tcp_established_next_t;
43 typedef enum _tcp_rcv_process_next
45 #define _(s,n) TCP_RCV_PROCESS_NEXT_##s,
46 foreach_tcp_state_next
48 TCP_RCV_PROCESS_N_NEXT,
49 } tcp_rcv_process_next_t;
51 typedef enum _tcp_syn_sent_next
53 #define _(s,n) TCP_SYN_SENT_NEXT_##s,
54 foreach_tcp_state_next
57 } tcp_syn_sent_next_t;
59 typedef enum _tcp_listen_next
61 #define _(s,n) TCP_LISTEN_NEXT_##s,
62 foreach_tcp_state_next
67 /* Generic, state independent indices */
68 typedef enum _tcp_state_next
70 #define _(s,n) TCP_NEXT_##s,
71 foreach_tcp_state_next
76 #define tcp_next_output(is_ip4) (is_ip4 ? TCP_NEXT_TCP4_OUTPUT \
77 : TCP_NEXT_TCP6_OUTPUT)
79 #define tcp_next_drop(is_ip4) (is_ip4 ? TCP_NEXT_DROP4 \
82 vlib_node_registration_t tcp4_established_node;
83 vlib_node_registration_t tcp6_established_node;
86 * Validate segment sequence number. As per RFC793:
88 * Segment Receive Test
90 * ------- ------- -------------------------------------------
91 * 0 0 SEG.SEQ = RCV.NXT
92 * 0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
94 * >0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
95 * or RCV.NXT =< SEG.SEQ+SEG.LEN-1 < RCV.NXT+RCV.WND
97 * This ultimately consists in checking if segment falls within the window.
98 * The one important difference compared to RFC793 is that we use rcv_las,
99 * or the rcv_nxt at last ack sent instead of rcv_nxt since that's the
100 * peer's reference when computing our receive window.
103 * seq_leq (end_seq, tc->rcv_las + tc->rcv_wnd) && seq_geq (seq, tc->rcv_las)
104 * however, is too strict when we have retransmits. Instead we just check that
105 * the seq is not beyond the right edge and that the end of the segment is not
106 * less than the left edge.
108 * N.B. rcv_nxt and rcv_wnd are both updated in this node if acks are sent, so
109 * use rcv_nxt in the right edge window test instead of rcv_las.
113 tcp_segment_in_rcv_wnd (tcp_connection_t * tc, u32 seq, u32 end_seq)
115 return (seq_geq (end_seq, tc->rcv_las)
116 && seq_leq (seq, tc->rcv_nxt + tc->rcv_wnd));
120 * Parse TCP header options.
122 * @param th TCP header
123 * @param to TCP options data structure to be populated
124 * @return -1 if parsing failed
127 tcp_options_parse (tcp_header_t * th, tcp_options_t * to)
130 u8 opt_len, opts_len, kind;
134 opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t);
135 data = (const u8 *) (th + 1);
137 /* Zero out all flags but those set in SYN */
138 to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE
139 | TCP_OPTS_FLAG_SACK);
141 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
145 /* Get options length */
146 if (kind == TCP_OPTION_EOL)
148 else if (kind == TCP_OPTION_NOOP)
160 /* weird option length */
161 if (opt_len < 2 || opt_len > opts_len)
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:
176 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
178 to->flags |= TCP_OPTS_FLAG_WSCALE;
179 to->wscale = data[2];
180 if (to->wscale > TCP_MAX_WND_SCALE)
182 clib_warning ("Illegal window scaling value: %d",
184 to->wscale = TCP_MAX_WND_SCALE;
188 case TCP_OPTION_TIMESTAMP:
189 if (opt_len == TCP_OPTION_LEN_TIMESTAMP)
191 to->flags |= TCP_OPTS_FLAG_TSTAMP;
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:
197 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
198 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
200 case TCP_OPTION_SACK_BLOCK:
201 /* If SACK permitted was not advertised or a SYN, break */
202 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
205 /* If too short or not correctly formatted, break */
206 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
209 to->flags |= TCP_OPTS_FLAG_SACK;
210 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
211 vec_reset_length (to->sacks);
212 for (j = 0; j < to->n_sack_blocks; j++)
214 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 8 * j));
215 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 8 * j));
216 vec_add1 (to->sacks, b);
220 /* Nothing to see here */
228 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
229 * timestamp to echo and it's less than tsval_recent, drop segment
230 * but still send an ACK in order to retain TCP's mechanism for detecting
231 * and recovering from half-open connections
233 * Or at least that's what the theory says. It seems that this might not work
234 * very well with packet reordering and fast retransmit. XXX
237 tcp_segment_check_paws (tcp_connection_t * tc)
239 return tcp_opts_tstamp (&tc->rcv_opts) && tc->tsval_recent
240 && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent);
244 * Update tsval recent
247 tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
250 * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
251 * of an incoming segment:
252 * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
253 * then the TSval from the segment is copied to TS.Recent;
254 * otherwise, the TSval is ignored.
256 if (tcp_opts_tstamp (&tc->rcv_opts) && seq_leq (seq, tc->rcv_las)
257 && seq_leq (tc->rcv_las, seq_end))
259 ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval));
260 tc->tsval_recent = tc->rcv_opts.tsval;
261 tc->tsval_recent_age = tcp_time_now ();
266 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
268 * It first verifies if segment has a wrapped sequence number (PAWS) and then
269 * does the processing associated to the first four steps (ignoring security
270 * and precedence): sequence number, rst bit and syn bit checks.
272 * @return 0 if segments passes validation.
275 tcp_segment_validate (vlib_main_t * vm, tcp_connection_t * tc0,
276 vlib_buffer_t * b0, tcp_header_t * th0,
277 u32 * next0, u32 * error0)
279 /* We could get a burst of RSTs interleaved with acks */
280 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
282 tcp_send_reset (tc0);
283 *error0 = TCP_ERROR_CONNECTION_CLOSED;
287 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
289 *error0 = TCP_ERROR_SEGMENT_INVALID;
293 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts)))
295 clib_warning ("options parse error");
296 *error0 = TCP_ERROR_OPTIONS;
300 if (PREDICT_FALSE (tcp_segment_check_paws (tc0)))
302 *error0 = TCP_ERROR_PAWS;
304 clib_warning ("paws failed\n%U", format_tcp_connection, tc0, 2);
305 TCP_EVT_DBG (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
306 vnet_buffer (b0)->tcp.seq_end);
308 /* If it just so happens that a segment updates tsval_recent for a
309 * segment over 24 days old, invalidate tsval_recent. */
310 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
313 /* Age isn't reset until we get a valid tsval (bsd inspired) */
314 tc0->tsval_recent = 0;
315 clib_warning ("paws failed - really old segment. REALLY?");
319 /* Drop after ack if not rst */
322 tcp_make_ack (tc0, b0);
323 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
330 /* 1st: check sequence number */
331 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
332 vnet_buffer (b0)->tcp.seq_end))
334 *error0 = TCP_ERROR_RCV_WND;
335 /* If our window is 0 and the packet is in sequence, let it pass
336 * through for ack processing. It should be dropped later. */
337 if (!(tc0->rcv_wnd == 0
338 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number))
340 /* If not RST, send dup ack */
343 tcp_make_ack (tc0, b0);
344 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
351 /* 2nd: check the RST bit */
352 if (PREDICT_FALSE (tcp_rst (th0)))
354 tcp_connection_reset (tc0);
355 *error0 = TCP_ERROR_RST_RCVD;
359 /* 3rd: check security and precedence (skip) */
361 /* 4th: check the SYN bit */
362 if (PREDICT_FALSE (tcp_syn (th0)))
364 /* TODO implement RFC 5961 */
365 if (tc0->state == TCP_STATE_SYN_RCVD)
367 tcp_make_synack (tc0, b0);
368 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0, 0);
372 tcp_make_ack (tc0, b0);
373 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, tc0);
378 /* If segment in window, save timestamp */
379 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
380 vnet_buffer (b0)->tcp.seq_end);
384 *next0 = tcp_next_drop (tc0->c_is_ip4);
387 *next0 = tcp_next_output (tc0->c_is_ip4);
392 tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0)
394 /* SND.UNA =< SEG.ACK =< SND.NXT */
395 return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number)
396 && seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt));
400 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
402 * Note that although the original article, srtt and rttvar are scaled
403 * to minimize round-off errors, here we don't. Instead, we rely on
404 * better precision time measurements.
406 * TODO support us rtt resolution
409 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
415 err = mrtt - tc->srtt;
417 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
418 * The increase should be bound */
419 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
420 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
421 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
425 /* First measurement. */
427 tc->rttvar = mrtt >> 1;
432 tcp_update_rto (tcp_connection_t * tc)
434 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
435 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
439 * Update RTT estimate and RTO timer
441 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
442 * timing. Middle boxes are known to fiddle with TCP options so we
443 * should give higher priority to ACK timing.
445 * This should be called only if previously sent bytes have been acked.
447 * return 1 if valid rtt 0 otherwise
450 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
454 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
455 * RTT because they're ambiguous. */
456 if (tcp_in_cong_recovery (tc) || tc->sack_sb.sacked_bytes)
458 if (tcp_in_recovery (tc))
463 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
465 mrtt = tcp_time_now () - tc->rtt_ts;
467 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
468 * snd_una, i.e., the left side of the send window:
469 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
470 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
472 mrtt = tcp_time_now () - tc->rcv_opts.tsecr;
475 /* Ignore dubious measurements */
476 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
479 tcp_estimate_rtt (tc, mrtt);
483 /* Allow measuring of a new RTT */
486 /* If we got here something must've been ACKed so make sure boff is 0,
487 * even if mrtt is not valid since we update the rto lower */
495 * Dequeue bytes that have been acked and while at it update RTT estimates.
498 tcp_dequeue_acked (tcp_connection_t * tc, u32 ack)
500 /* Dequeue the newly ACKed add SACKed bytes */
501 stream_session_dequeue_drop (&tc->connection,
502 tc->bytes_acked + tc->sack_sb.snd_una_adv);
504 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
506 /* Update rtt and rto */
507 tcp_update_rtt (tc, ack);
509 /* If everything has been acked, stop retransmit timer
510 * otherwise update. */
511 tcp_retransmit_timer_update (tc);
515 * Check if duplicate ack as per RFC5681 Sec. 2
518 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
521 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
522 && seq_gt (tc->snd_una_max, tc->snd_una)
523 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
524 && (prev_snd_wnd == tc->snd_wnd));
528 * Checks if ack is a congestion control event.
531 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
532 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
534 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
535 * defined to be 'duplicate' */
536 *is_dack = tc->sack_sb.last_sacked_bytes
537 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
539 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
543 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
545 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
546 return hole - sb->holes;
550 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
552 return hole->end - hole->start;
555 sack_scoreboard_hole_t *
556 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
558 if (index != TCP_INVALID_SACK_HOLE_INDEX)
559 return pool_elt_at_index (sb->holes, index);
563 sack_scoreboard_hole_t *
564 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
566 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
567 return pool_elt_at_index (sb->holes, hole->next);
571 sack_scoreboard_hole_t *
572 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
574 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
575 return pool_elt_at_index (sb->holes, hole->prev);
579 sack_scoreboard_hole_t *
580 scoreboard_first_hole (sack_scoreboard_t * sb)
582 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
583 return pool_elt_at_index (sb->holes, sb->head);
587 sack_scoreboard_hole_t *
588 scoreboard_last_hole (sack_scoreboard_t * sb)
590 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
591 return pool_elt_at_index (sb->holes, sb->tail);
596 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
598 sack_scoreboard_hole_t *next, *prev;
600 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
602 next = pool_elt_at_index (sb->holes, hole->next);
603 next->prev = hole->prev;
607 sb->tail = hole->prev;
610 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
612 prev = pool_elt_at_index (sb->holes, hole->prev);
613 prev->next = hole->next;
617 sb->head = hole->next;
620 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
621 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
623 /* Poison the entry */
625 clib_memset (hole, 0xfe, sizeof (*hole));
627 pool_put (sb->holes, hole);
630 static sack_scoreboard_hole_t *
631 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
634 sack_scoreboard_hole_t *hole, *next, *prev;
637 pool_get (sb->holes, hole);
638 clib_memset (hole, 0, sizeof (*hole));
642 hole_index = scoreboard_hole_index (sb, hole);
644 prev = scoreboard_get_hole (sb, prev_index);
647 hole->prev = prev_index;
648 hole->next = prev->next;
650 if ((next = scoreboard_next_hole (sb, hole)))
651 next->prev = hole_index;
653 sb->tail = hole_index;
655 prev->next = hole_index;
659 sb->head = hole_index;
660 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
661 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
668 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
670 sack_scoreboard_hole_t *left, *right;
671 u32 bytes = 0, blks = 0;
674 sb->sacked_bytes = 0;
675 left = scoreboard_last_hole (sb);
679 if (seq_gt (sb->high_sacked, left->end))
681 bytes = sb->high_sacked - left->end;
685 while ((right = left)
686 && bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
687 && blks < TCP_DUPACK_THRESHOLD
688 /* left not updated if above conditions fail */
689 && (left = scoreboard_prev_hole (sb, right)))
691 bytes += right->start - left->end;
695 /* left is first lost */
700 sb->lost_bytes += scoreboard_hole_bytes (right);
702 left = scoreboard_prev_hole (sb, right);
704 bytes += right->start - left->end;
706 while ((right = left));
709 sb->sacked_bytes = bytes;
713 * Figure out the next hole to retransmit
715 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
717 sack_scoreboard_hole_t *
718 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
719 sack_scoreboard_hole_t * start,
721 u8 * can_rescue, u8 * snd_limited)
723 sack_scoreboard_hole_t *hole = 0;
725 hole = start ? start : scoreboard_first_hole (sb);
726 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
727 hole = scoreboard_next_hole (sb, hole);
729 /* Nothing, return */
732 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
736 /* Rule (1): if higher than rxt, less than high_sacked and lost */
737 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
739 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
743 /* Rule (2): output takes care of transmitting new data */
744 if (!have_sent_1_smss)
747 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
749 /* Rule (3): if hole not lost */
750 else if (seq_lt (hole->start, sb->high_sacked))
753 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
755 /* Rule (4): if hole beyond high_sacked */
758 ASSERT (seq_geq (hole->start, sb->high_sacked));
761 /* HighRxt MUST NOT be updated */
766 if (hole && seq_lt (sb->high_rxt, hole->start))
767 sb->high_rxt = hole->start;
773 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 seq)
775 sack_scoreboard_hole_t *hole;
776 hole = scoreboard_first_hole (sb);
779 seq = seq_gt (seq, hole->start) ? seq : hole->start;
780 sb->cur_rxt_hole = sb->head;
786 scoreboard_init (sack_scoreboard_t * sb)
788 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
789 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
790 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
794 scoreboard_clear (sack_scoreboard_t * sb)
796 sack_scoreboard_hole_t *hole;
797 while ((hole = scoreboard_first_hole (sb)))
799 scoreboard_remove_hole (sb, hole);
801 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
802 ASSERT (pool_elts (sb->holes) == 0);
803 sb->sacked_bytes = 0;
804 sb->last_sacked_bytes = 0;
805 sb->last_bytes_delivered = 0;
810 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
814 * Test that scoreboard is sane after recovery
816 * Returns 1 if scoreboard is empty or if first hole beyond
820 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
822 sack_scoreboard_hole_t *hole;
823 hole = scoreboard_first_hole (&tc->sack_sb);
824 return (!hole || (seq_geq (hole->start, tc->snd_una)
825 && seq_lt (hole->end, tc->snd_una_max)));
829 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
831 sack_scoreboard_t *sb = &tc->sack_sb;
832 sack_block_t *blk, tmp;
833 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
834 u32 blk_index = 0, old_sacked_bytes, hole_index;
837 sb->last_sacked_bytes = 0;
838 sb->last_bytes_delivered = 0;
841 if (!tcp_opts_sack (&tc->rcv_opts)
842 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
845 old_sacked_bytes = sb->sacked_bytes;
847 /* Remove invalid blocks */
848 blk = tc->rcv_opts.sacks;
849 while (blk < vec_end (tc->rcv_opts.sacks))
851 if (seq_lt (blk->start, blk->end)
852 && seq_gt (blk->start, tc->snd_una)
853 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_una_max))
858 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
861 /* Add block for cumulative ack */
862 if (seq_gt (ack, tc->snd_una))
864 tmp.start = tc->snd_una;
866 vec_add1 (tc->rcv_opts.sacks, tmp);
869 if (vec_len (tc->rcv_opts.sacks) == 0)
872 tcp_scoreboard_trace_add (tc, ack);
874 /* Make sure blocks are ordered */
875 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
876 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
877 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
879 tmp = tc->rcv_opts.sacks[i];
880 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
881 tc->rcv_opts.sacks[j] = tmp;
884 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
886 /* If no holes, insert the first that covers all outstanding bytes */
887 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
888 tc->snd_una, tc->snd_una_max);
889 sb->tail = scoreboard_hole_index (sb, last_hole);
890 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
891 sb->high_sacked = tmp.end;
895 /* If we have holes but snd_una_max is beyond the last hole, update
897 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
898 last_hole = scoreboard_last_hole (sb);
899 if (seq_gt (tc->snd_una_max, last_hole->end))
901 if (seq_geq (last_hole->start, sb->high_sacked))
903 last_hole->end = tc->snd_una_max;
905 /* New hole after high sacked block */
906 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
908 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
912 /* Keep track of max byte sacked for when the last hole
914 if (seq_gt (tmp.end, sb->high_sacked))
915 sb->high_sacked = tmp.end;
918 /* Walk the holes with the SACK blocks */
919 hole = pool_elt_at_index (sb->holes, sb->head);
920 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
922 blk = &tc->rcv_opts.sacks[blk_index];
923 if (seq_leq (blk->start, hole->start))
925 /* Block covers hole. Remove hole */
926 if (seq_geq (blk->end, hole->end))
928 next_hole = scoreboard_next_hole (sb, hole);
930 /* Byte accounting: snd_una needs to be advanced */
935 if (seq_lt (ack, next_hole->start))
936 sb->snd_una_adv = next_hole->start - ack;
937 sb->last_bytes_delivered +=
938 next_hole->start - hole->end;
942 ASSERT (seq_geq (sb->high_sacked, ack));
943 sb->snd_una_adv = sb->high_sacked - ack;
944 sb->last_bytes_delivered += sb->high_sacked - hole->end;
948 scoreboard_remove_hole (sb, hole);
951 /* Partial 'head' overlap */
954 if (seq_gt (blk->end, hole->start))
956 hole->start = blk->end;
963 /* Hole must be split */
964 if (seq_lt (blk->end, hole->end))
966 hole_index = scoreboard_hole_index (sb, hole);
967 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
970 /* Pool might've moved */
971 hole = scoreboard_get_hole (sb, hole_index);
972 hole->end = blk->start;
974 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
976 else if (seq_lt (blk->start, hole->end))
978 hole->end = blk->start;
980 hole = scoreboard_next_hole (sb, hole);
984 if (pool_elts (sb->holes) == 1)
986 hole = scoreboard_first_hole (sb);
987 if (hole->start == ack + sb->snd_una_adv
988 && hole->end == tc->snd_una_max)
989 scoreboard_remove_hole (sb, hole);
992 scoreboard_update_bytes (tc, sb);
993 sb->last_sacked_bytes = sb->sacked_bytes
994 - (old_sacked_bytes - sb->last_bytes_delivered);
995 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
996 ASSERT (sb->sacked_bytes == 0
997 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
998 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
999 - seq_max (tc->snd_una, ack));
1000 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1001 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
1002 TCP_EVT_DBG (TCP_EVT_CC_SCOREBOARD, tc);
1006 * Try to update snd_wnd based on feedback received from peer.
1008 * If successful, and new window is 'effectively' 0, activate persist
1012 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1014 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1015 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1016 if (seq_lt (tc->snd_wl1, seq)
1017 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1019 tc->snd_wnd = snd_wnd;
1022 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
1024 if (tc->snd_wnd < tc->snd_mss)
1026 /* Set persist timer if not set and we just got 0 wnd */
1027 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1028 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1029 tcp_persist_timer_set (tc);
1033 tcp_persist_timer_reset (tc);
1034 if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
1037 tcp_update_rto (tc);
1044 * Init loss recovery/fast recovery.
1046 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1047 * updated in @ref tcp_cc_handle_event after fast retransmit
1050 tcp_cc_init_congestion (tcp_connection_t * tc)
1052 tcp_fastrecovery_on (tc);
1053 tc->snd_congestion = tc->snd_una_max;
1054 tc->cwnd_acc_bytes = 0;
1055 tc->cc_algo->congestion (tc);
1056 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
1060 tcp_cc_recovery_exit (tcp_connection_t * tc)
1063 tcp_update_rto (tc);
1065 tc->snd_nxt = tc->snd_una_max;
1066 tcp_recovery_off (tc);
1067 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1071 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
1073 tc->cc_algo->recovered (tc);
1074 tc->snd_rxt_bytes = 0;
1075 tc->rcv_dupacks = 0;
1076 tc->snd_nxt = tc->snd_una_max;
1077 tcp_fastrecovery_off (tc);
1078 tcp_fastrecovery_1_smss_off (tc);
1079 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1083 tcp_cc_congestion_undo (tcp_connection_t * tc)
1085 tc->cwnd = tc->prev_cwnd;
1086 tc->ssthresh = tc->prev_ssthresh;
1087 tc->snd_nxt = tc->snd_una_max;
1088 tc->rcv_dupacks = 0;
1089 if (tcp_in_recovery (tc))
1090 tcp_cc_recovery_exit (tc);
1091 ASSERT (tc->rto_boff == 0);
1092 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
1093 /* TODO extend for fastrecovery */
1097 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1099 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1101 && tcp_opts_tstamp (&tc->rcv_opts)
1102 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1106 tcp_cc_recover (tcp_connection_t * tc)
1108 ASSERT (tcp_in_cong_recovery (tc));
1109 if (tcp_cc_is_spurious_retransmit (tc))
1111 tcp_cc_congestion_undo (tc);
1115 if (tcp_in_recovery (tc))
1116 tcp_cc_recovery_exit (tc);
1117 else if (tcp_in_fastrecovery (tc))
1118 tcp_cc_fastrecovery_exit (tc);
1120 ASSERT (tc->rto_boff == 0);
1121 ASSERT (!tcp_in_cong_recovery (tc));
1122 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1127 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
1129 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1131 /* Congestion avoidance */
1132 tc->cc_algo->rcv_ack (tc);
1133 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1135 /* If a cumulative ack, make sure dupacks is 0 */
1136 tc->rcv_dupacks = 0;
1138 /* When dupacks hits the threshold we only enter fast retransmit if
1139 * cumulative ack covers more than snd_congestion. Should snd_una
1140 * wrap this test may fail under otherwise valid circumstances.
1141 * Therefore, proactively update snd_congestion when wrap detected. */
1143 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1144 && seq_gt (tc->snd_congestion, tc->snd_una)))
1145 tc->snd_congestion = tc->snd_una - 1;
1149 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1151 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1155 tcp_should_fastrecover (tcp_connection_t * tc)
1157 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1158 || tcp_should_fastrecover_sack (tc));
1162 * One function to rule them all ... and in the darkness bind them
1165 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1169 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1171 if (tc->bytes_acked)
1173 tcp_fast_retransmit (tc);
1177 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1178 * it account for the bytes that left the network.
1180 else if (is_dack && !tcp_in_recovery (tc))
1182 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1183 ASSERT (tc->snd_una != tc->snd_una_max
1184 || tc->sack_sb.last_sacked_bytes);
1188 /* Pure duplicate ack. If some data got acked, it's handled lower */
1189 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1191 ASSERT (tcp_in_fastrecovery (tc));
1192 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1195 else if (tcp_should_fastrecover (tc))
1197 ASSERT (!tcp_in_fastrecovery (tc));
1199 /* If of of the two conditions lower hold, reset dupacks because
1200 * we're probably after timeout (RFC6582 heuristics).
1201 * If Cumulative ack does not cover more than congestion threshold,
1203 * 1) The following doesn't hold: The congestion window is greater
1204 * than SMSS bytes and the difference between highest_ack
1205 * and prev_highest_ack is at most 4*SMSS bytes
1206 * 2) Echoed timestamp in the last non-dup ack does not equal the
1209 if (seq_leq (tc->snd_una, tc->snd_congestion)
1210 && ((!(tc->cwnd > tc->snd_mss
1211 && tc->bytes_acked <= 4 * tc->snd_mss))
1212 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1214 tc->rcv_dupacks = 0;
1218 tcp_cc_init_congestion (tc);
1219 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1221 /* The first segment MUST be retransmitted */
1222 tcp_retransmit_first_unacked (tc);
1224 /* Post retransmit update cwnd to ssthresh and account for the
1225 * three segments that have left the network and should've been
1226 * buffered at the receiver XXX */
1227 tc->cwnd = tc->ssthresh + tc->rcv_dupacks * tc->snd_mss;
1228 ASSERT (tc->cwnd >= tc->snd_mss);
1230 /* If cwnd allows, send more data */
1231 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1233 scoreboard_init_high_rxt (&tc->sack_sb,
1234 tc->snd_una + tc->snd_mss);
1235 tcp_fast_retransmit_sack (tc);
1239 tcp_fast_retransmit_no_sack (tc);
1243 else if (!tc->bytes_acked
1244 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1246 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1253 if (!tc->bytes_acked)
1257 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1260 * Legitimate ACK. 1) See if we can exit recovery
1262 /* XXX limit this only to first partial ack? */
1263 if (seq_lt (tc->snd_una, tc->snd_congestion))
1264 tcp_retransmit_timer_force_update (tc);
1266 tcp_retransmit_timer_update (tc);
1268 if (seq_geq (tc->snd_una, tc->snd_congestion))
1270 /* If spurious return, we've already updated everything */
1271 if (tcp_cc_recover (tc))
1273 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1277 tc->snd_nxt = tc->snd_una_max;
1279 /* Treat as congestion avoidance ack */
1280 tc->cc_algo->rcv_ack (tc);
1281 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1286 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1289 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1290 * reset dupacks to 0. Also needed if in congestion recovery */
1291 tc->rcv_dupacks = 0;
1293 /* Post RTO timeout don't try anything fancy */
1294 if (tcp_in_recovery (tc))
1296 tc->cc_algo->rcv_ack (tc);
1297 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1298 transport_add_tx_event (&tc->connection);
1302 /* Remove retransmitted bytes that have been delivered */
1303 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1304 >= tc->sack_sb.last_bytes_delivered
1305 || (tc->flags & TCP_CONN_FINSNT));
1307 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1309 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1310 * remove sacked bytes delivered */
1311 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1312 - tc->sack_sb.last_bytes_delivered;
1313 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1314 tc->snd_rxt_bytes -= rxt_delivered;
1318 /* Either all retransmitted holes have been acked, or we're
1319 * "in the blind" and retransmitting segment by segment */
1320 tc->snd_rxt_bytes = 0;
1323 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1326 * Since this was a partial ack, try to retransmit some more data
1328 tcp_fast_retransmit (tc);
1332 * Process incoming ACK
1335 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
1336 tcp_header_t * th, u32 * next, u32 * error)
1338 u32 prev_snd_wnd, prev_snd_una;
1341 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1343 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1344 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1346 /* When we entered recovery, we reset snd_nxt to snd_una. Seems peer
1347 * still has the data so accept the ack */
1348 if (tcp_in_recovery (tc)
1349 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_congestion))
1351 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1352 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
1353 tc->snd_una_max = tc->snd_nxt;
1357 /* If we have outstanding data and this is within the window, accept it,
1358 * probably retransmit has timed out. Otherwise ACK segment and then
1360 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1362 tcp_make_ack (tc, b);
1363 *next = tcp_next_output (tc->c_is_ip4);
1364 *error = TCP_ERROR_ACK_INVALID;
1365 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1366 vnet_buffer (b)->tcp.ack_number);
1370 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1371 vnet_buffer (b)->tcp.ack_number);
1373 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1374 *error = TCP_ERROR_ACK_FUTURE;
1377 /* If old ACK, probably it's an old dupack */
1378 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1380 *error = TCP_ERROR_ACK_OLD;
1381 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1382 vnet_buffer (b)->tcp.ack_number);
1383 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1384 tcp_cc_handle_event (tc, 1);
1385 /* Don't drop yet */
1390 * Looks okay, process feedback
1393 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1394 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1396 prev_snd_wnd = tc->snd_wnd;
1397 prev_snd_una = tc->snd_una;
1398 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1399 vnet_buffer (b)->tcp.ack_number,
1400 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1401 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1402 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1403 tcp_validate_txf_size (tc, tc->bytes_acked);
1405 if (tc->bytes_acked)
1406 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
1408 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1411 * Check if we have congestion event
1414 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1416 tcp_cc_handle_event (tc, is_dack);
1417 if (!tcp_in_cong_recovery (tc))
1419 *error = TCP_ERROR_ACK_DUP;
1420 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1426 * Update congestion control (slow start/congestion avoidance)
1428 tcp_cc_update (tc, b);
1429 *error = TCP_ERROR_ACK_OK;
1434 tcp_sack_vector_is_sane (sack_block_t * sacks)
1437 for (i = 1; i < vec_len (sacks); i++)
1439 if (sacks[i - 1].end == sacks[i].start)
1446 * Build SACK list as per RFC2018.
1448 * Makes sure the first block contains the segment that generated the current
1449 * ACK and the following ones are the ones most recently reported in SACK
1452 * @param tc TCP connection for which the SACK list is updated
1453 * @param start Start sequence number of the newest SACK block
1454 * @param end End sequence of the newest SACK block
1457 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1459 sack_block_t *new_list = 0, *block = 0;
1462 /* If the first segment is ooo add it to the list. Last write might've moved
1463 * rcv_nxt over the first segment. */
1464 if (seq_lt (tc->rcv_nxt, start))
1466 vec_add2 (new_list, block, 1);
1467 block->start = start;
1471 /* Find the blocks still worth keeping. */
1472 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1474 /* Discard if rcv_nxt advanced beyond current block */
1475 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1478 /* Merge or drop if segment overlapped by the new segment */
1479 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1480 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1482 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1483 new_list[0].start = tc->snd_sacks[i].start;
1484 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1485 new_list[0].end = tc->snd_sacks[i].end;
1489 /* Save to new SACK list if we have space. */
1490 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1492 vec_add1 (new_list, tc->snd_sacks[i]);
1496 clib_warning ("sack discarded");
1500 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1502 /* Replace old vector with new one */
1503 vec_free (tc->snd_sacks);
1504 tc->snd_sacks = new_list;
1506 /* Segments should not 'touch' */
1507 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1511 tcp_sack_list_bytes (tcp_connection_t * tc)
1514 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1515 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1519 /** Enqueue data for delivery to application */
1521 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1524 int written, error = TCP_ERROR_ENQUEUED;
1526 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1528 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1529 1 /* queue event */ , 1);
1531 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1533 /* Update rcv_nxt */
1534 if (PREDICT_TRUE (written == data_len))
1536 tc->rcv_nxt += written;
1538 /* If more data written than expected, account for out-of-order bytes. */
1539 else if (written > data_len)
1541 tc->rcv_nxt += written;
1543 /* Send ACK confirming the update */
1544 tc->flags |= TCP_CONN_SNDACK;
1545 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1547 else if (written > 0)
1549 /* We've written something but FIFO is probably full now */
1550 tc->rcv_nxt += written;
1552 /* Depending on how fast the app is, all remaining buffers in burst will
1553 * not be enqueued. Inform peer */
1554 tc->flags |= TCP_CONN_SNDACK;
1556 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1560 tc->flags |= TCP_CONN_SNDACK;
1561 return TCP_ERROR_FIFO_FULL;
1564 /* Update SACK list if need be */
1565 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1567 /* Remove SACK blocks that have been delivered */
1568 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1574 /** Enqueue out-of-order data */
1576 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1579 stream_session_t *s0;
1582 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1585 /* Enqueue out-of-order data with relative offset */
1586 rv = session_enqueue_stream_connection (&tc->connection, b,
1587 vnet_buffer (b)->tcp.seq_number -
1588 tc->rcv_nxt, 0 /* queue event */ ,
1591 /* Nothing written */
1594 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1595 return TCP_ERROR_FIFO_FULL;
1598 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1600 /* Update SACK list if in use */
1601 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1603 ooo_segment_t *newest;
1606 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1608 /* Get the newest segment from the fifo */
1609 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1612 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1613 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1614 start = tc->rcv_nxt + offset;
1615 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1616 tcp_update_sack_list (tc, start, end);
1617 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1618 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1622 return TCP_ERROR_ENQUEUED_OOO;
1626 * Check if ACK could be delayed. If ack can be delayed, it should return
1627 * true for a full frame. If we're always acking return 0.
1630 tcp_can_delack (tcp_connection_t * tc)
1632 /* Send ack if ... */
1634 /* just sent a rcv wnd 0 */
1635 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1636 /* constrained to send ack */
1637 || (tc->flags & TCP_CONN_SNDACK) != 0
1638 /* we're almost out of tx wnd */
1639 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1646 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1648 u32 discard, first = b->current_length;
1649 vlib_main_t *vm = vlib_get_main ();
1651 /* Handle multi-buffer segments */
1652 if (n_bytes_to_drop > b->current_length)
1654 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1658 discard = clib_min (n_bytes_to_drop, b->current_length);
1659 vlib_buffer_advance (b, discard);
1660 b = vlib_get_buffer (vm, b->next_buffer);
1661 n_bytes_to_drop -= discard;
1663 while (n_bytes_to_drop);
1664 if (n_bytes_to_drop > first)
1665 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1668 vlib_buffer_advance (b, n_bytes_to_drop);
1669 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1674 * Receive buffer for connection and handle acks
1676 * It handles both in order or out-of-order data.
1679 tcp_segment_rcv (tcp_connection_t * tc, vlib_buffer_t * b, u32 * next0)
1681 u32 error, n_bytes_to_drop, n_data_bytes;
1683 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1684 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1685 ASSERT (n_data_bytes);
1687 /* Handle out-of-order data */
1688 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1690 /* Old sequence numbers allowed through because they overlapped
1692 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1694 /* Completely in the past (possible retransmit). Ack
1695 * retransmissions since we may not have any data to send */
1696 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1698 tcp_make_ack (tc, b);
1699 error = TCP_ERROR_SEGMENT_OLD;
1700 *next0 = tcp_next_output (tc->c_is_ip4);
1704 /* Chop off the bytes in the past and see if what is left
1705 * can be enqueued in order */
1706 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1707 n_data_bytes -= n_bytes_to_drop;
1708 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1709 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1711 error = TCP_ERROR_SEGMENT_OLD;
1712 *next0 = tcp_next_drop (tc->c_is_ip4);
1718 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1719 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1720 *next0 = tcp_next_output (tc->c_is_ip4);
1721 tcp_make_ack (tc, b);
1722 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1723 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1729 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1730 * segments can be enqueued after fifo tail offset changes. */
1731 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1732 if (tcp_can_delack (tc))
1734 *next0 = tcp_next_drop (tc->c_is_ip4);
1735 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1736 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1740 *next0 = tcp_next_output (tc->c_is_ip4);
1741 tcp_make_ack (tc, b);
1749 tcp_header_t tcp_header;
1750 tcp_connection_t tcp_connection;
1754 format_tcp_rx_trace (u8 * s, va_list * args)
1756 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1757 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1758 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1759 u32 indent = format_get_indent (s);
1761 s = format (s, "%U\n%U%U",
1762 format_tcp_header, &t->tcp_header, 128,
1763 format_white_space, indent,
1764 format_tcp_connection, &t->tcp_connection, 1);
1770 format_tcp_rx_trace_short (u8 * s, va_list * args)
1772 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1773 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1774 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1776 s = format (s, "%d -> %d (%U)",
1777 clib_net_to_host_u16 (t->tcp_header.dst_port),
1778 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
1779 t->tcp_connection.state);
1785 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1786 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1790 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1794 th0 = tcp_buffer_hdr (b0);
1796 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1800 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
1801 vlib_frame_t * frame, u8 is_ip4)
1805 n_left = frame->n_vectors;
1806 from = vlib_frame_vector_args (frame);
1810 tcp_connection_t *tc0;
1817 b0 = vlib_get_buffer (vm, bi0);
1819 if (b0->flags & VLIB_BUFFER_IS_TRACED)
1821 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1822 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1824 th0 = tcp_buffer_hdr (b0);
1825 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1834 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
1835 u8 is_ip4, u32 evt, u32 val)
1838 vlib_node_increment_counter (vm, tcp4_node, evt, val);
1840 vlib_node_increment_counter (vm, tcp6_node, evt, val);
1843 #define tcp_maybe_inc_counter(node_id, err, count) \
1845 if (next0 != tcp_next_drop (is_ip4)) \
1846 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1847 tcp6_##node_id##_node.index, is_ip4, err, \
1850 #define tcp_inc_counter(node_id, err, count) \
1851 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1852 tcp6_##node_id##_node.index, is_ip4, \
1854 #define tcp_maybe_inc_err_counter(cnts, err) \
1856 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
1858 #define tcp_inc_err_counter(cnts, err, val) \
1862 #define tcp_store_err_counters(node_id, cnts) \
1865 for (i = 0; i < TCP_N_ERROR; i++) \
1867 tcp_inc_counter(node_id, i, cnts[i]); \
1872 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1873 vlib_frame_t * frame, int is_ip4)
1875 u32 thread_index = vm->thread_index, errors = 0;
1876 u32 n_left_from, next_index, *from, *to_next;
1877 u16 err_counters[TCP_N_ERROR] = { 0 };
1880 if (node->flags & VLIB_NODE_FLAG_TRACE)
1881 tcp_established_trace_frame (vm, node, frame, is_ip4);
1883 from = vlib_frame_vector_args (frame);
1884 n_left_from = frame->n_vectors;
1885 next_index = node->cached_next_index;
1887 while (n_left_from > 0)
1891 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1892 while (n_left_from > 0 && n_left_to_next > 0)
1896 tcp_header_t *th0 = 0;
1897 tcp_connection_t *tc0;
1898 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ACK_OK;
1900 if (n_left_from > 1)
1903 pb = vlib_get_buffer (vm, from[1]);
1904 vlib_prefetch_buffer_header (pb, LOAD);
1905 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
1913 n_left_to_next -= 1;
1915 b0 = vlib_get_buffer (vm, bi0);
1916 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1919 if (PREDICT_FALSE (tc0 == 0))
1921 error0 = TCP_ERROR_INVALID_CONNECTION;
1925 th0 = tcp_buffer_hdr (b0);
1926 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
1927 * dangling reference. */
1928 is_fin = tcp_is_fin (th0);
1930 /* SYNs, FINs and data consume sequence numbers */
1931 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1932 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
1934 /* TODO header prediction fast path */
1936 /* 1-4: check SEQ, RST, SYN */
1937 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0,
1940 tcp_maybe_inc_err_counter (err_counters, error0);
1941 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
1945 /* 5: check the ACK field */
1946 if (PREDICT_FALSE (tcp_rcv_ack (tc0, b0, th0, &next0, &error0)))
1948 tcp_maybe_inc_err_counter (err_counters, error0);
1952 /* 6: check the URG bit TODO */
1954 /* 7: process the segment text */
1955 if (vnet_buffer (b0)->tcp.data_len)
1957 error0 = tcp_segment_rcv (tc0, b0, &next0);
1958 tcp_maybe_inc_err_counter (err_counters, error0);
1961 /* 8: check the FIN bit */
1962 if (PREDICT_FALSE (is_fin))
1964 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1965 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1966 /* Account for the FIN if nothing else was received */
1967 if (vnet_buffer (b0)->tcp.data_len == 0)
1969 tcp_make_ack (tc0, b0);
1970 next0 = tcp_next_output (tc0->c_is_ip4);
1971 tc0->state = TCP_STATE_CLOSE_WAIT;
1972 stream_session_disconnect_notify (&tc0->connection);
1973 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1974 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1975 tcp_inc_err_counter (err_counters, TCP_ERROR_FIN_RCVD, 1);
1979 b0->error = node->errors[error0];
1980 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1981 n_left_to_next, bi0, next0);
1984 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1987 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
1989 err_counters[TCP_ERROR_EVENT_FIFO_FULL] = errors;
1990 tcp_store_err_counters (established, err_counters);
1991 tcp_flush_frame_to_output (vm, thread_index, is_ip4);
1993 return frame->n_vectors;
1997 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1998 vlib_frame_t * from_frame)
2000 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2004 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2005 vlib_frame_t * from_frame)
2007 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2011 VLIB_REGISTER_NODE (tcp4_established_node) =
2013 .function = tcp4_established,
2014 .name = "tcp4-established",
2015 /* Takes a vector of packets. */
2016 .vector_size = sizeof (u32),
2017 .n_errors = TCP_N_ERROR,
2018 .error_strings = tcp_error_strings,
2019 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2022 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2023 foreach_tcp_state_next
2026 .format_trace = format_tcp_rx_trace_short,
2030 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
2033 VLIB_REGISTER_NODE (tcp6_established_node) =
2035 .function = tcp6_established,
2036 .name = "tcp6-established",
2037 /* Takes a vector of packets. */
2038 .vector_size = sizeof (u32),
2039 .n_errors = TCP_N_ERROR,
2040 .error_strings = tcp_error_strings,
2041 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2044 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2045 foreach_tcp_state_next
2048 .format_trace = format_tcp_rx_trace_short,
2053 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
2055 vlib_node_registration_t tcp4_syn_sent_node;
2056 vlib_node_registration_t tcp6_syn_sent_node;
2059 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2061 transport_connection_t *tmp = 0;
2068 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2071 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2072 && (tc->state == TCP_STATE_LISTEN
2073 || tc->c_rmt_port == hdr->src_port));
2077 handle = session_lookup_half_open_handle (&tc->connection);
2078 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2079 tc->c_proto, tc->c_is_ip4);
2083 if (tmp->lcl_port == hdr->dst_port
2084 && tmp->rmt_port == hdr->src_port)
2086 TCP_DBG ("half-open is valid!");
2094 * Lookup transport connection
2096 static tcp_connection_t *
2097 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2101 transport_connection_t *tconn;
2102 tcp_connection_t *tc;
2107 ip4 = vlib_buffer_get_current (b);
2108 tcp = ip4_next_header (ip4);
2109 tconn = session_lookup_connection_wt4 (fib_index,
2114 TRANSPORT_PROTO_TCP,
2115 thread_index, &is_filtered);
2116 tc = tcp_get_connection_from_transport (tconn);
2117 ASSERT (tcp_lookup_is_valid (tc, tcp));
2122 ip6 = vlib_buffer_get_current (b);
2123 tcp = ip6_next_header (ip6);
2124 tconn = session_lookup_connection_wt6 (fib_index,
2129 TRANSPORT_PROTO_TCP,
2130 thread_index, &is_filtered);
2131 tc = tcp_get_connection_from_transport (tconn);
2132 ASSERT (tcp_lookup_is_valid (tc, tcp));
2138 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2139 vlib_frame_t * from_frame, int is_ip4)
2141 tcp_main_t *tm = vnet_get_tcp_main ();
2142 u32 n_left_from, next_index, *from, *to_next;
2143 u32 my_thread_index = vm->thread_index, errors = 0;
2145 from = vlib_frame_vector_args (from_frame);
2146 n_left_from = from_frame->n_vectors;
2148 next_index = node->cached_next_index;
2150 while (n_left_from > 0)
2154 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2156 while (n_left_from > 0 && n_left_to_next > 0)
2158 u32 bi0, ack0, seq0;
2161 tcp_header_t *tcp0 = 0;
2162 tcp_connection_t *tc0;
2163 tcp_connection_t *new_tc0;
2164 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ENQUEUED;
2171 n_left_to_next -= 1;
2173 b0 = vlib_get_buffer (vm, bi0);
2175 tcp_half_open_connection_get (vnet_buffer (b0)->
2176 tcp.connection_index);
2177 if (PREDICT_FALSE (tc0 == 0))
2179 error0 = TCP_ERROR_INVALID_CONNECTION;
2183 /* Half-open completed recently but the connection was't removed
2184 * yet by the owning thread */
2185 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2187 /* Make sure the connection actually exists */
2188 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2189 my_thread_index, is_ip4));
2193 ack0 = vnet_buffer (b0)->tcp.ack_number;
2194 seq0 = vnet_buffer (b0)->tcp.seq_number;
2195 tcp0 = tcp_buffer_hdr (b0);
2197 /* Crude check to see if the connection handle does not match
2198 * the packet. Probably connection just switched to established */
2199 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2200 || tcp0->src_port != tc0->c_rmt_port))
2204 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
2207 /* SYNs, FINs and data consume sequence numbers */
2208 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
2209 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
2212 * 1. check the ACK bit
2216 * If the ACK bit is set
2217 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2218 * the RST bit is set, if so drop the segment and return)
2219 * <SEQ=SEG.ACK><CTL=RST>
2220 * and discard the segment. Return.
2221 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2225 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2227 clib_warning ("ack not in rcv wnd");
2228 if (!tcp_rst (tcp0))
2229 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2233 /* Make sure ACK is valid */
2234 if (seq_gt (tc0->snd_una, ack0))
2236 clib_warning ("ack invalid");
2242 * 2. check the RST bit
2247 /* If ACK is acceptable, signal client that peer is not
2248 * willing to accept connection and drop connection*/
2250 tcp_connection_reset (tc0);
2255 * 3. check the security and precedence (skipped)
2259 * 4. check the SYN bit
2262 /* No SYN flag. Drop. */
2263 if (!tcp_syn (tcp0))
2265 clib_warning ("not synack");
2270 if (tcp_options_parse (tcp0, &tc0->rcv_opts))
2272 clib_warning ("options parse fail");
2276 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2277 * current thread pool. */
2278 pool_get (tm->connections[my_thread_index], new_tc0);
2279 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
2280 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2281 new_tc0->c_thread_index = my_thread_index;
2282 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2283 new_tc0->irs = seq0;
2284 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
2285 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] =
2286 TCP_TIMER_HANDLE_INVALID;
2287 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2289 /* If this is not the owning thread, wait for syn retransmit to
2290 * expire and cleanup then */
2291 if (tcp_half_open_connection_cleanup (tc0))
2292 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2294 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2296 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2297 new_tc0->tsval_recent_age = tcp_time_now ();
2300 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2301 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2303 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2304 << new_tc0->snd_wscale;
2305 new_tc0->snd_wl1 = seq0;
2306 new_tc0->snd_wl2 = ack0;
2308 tcp_connection_init_vars (new_tc0);
2310 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2311 if (PREDICT_TRUE (tcp_ack (tcp0)))
2313 /* Our SYN is ACKed: we have iss < ack = snd_una */
2315 /* TODO Dequeue acknowledged segments if we support Fast Open */
2316 new_tc0->snd_una = ack0;
2317 new_tc0->state = TCP_STATE_ESTABLISHED;
2319 /* Make sure las is initialized for the wnd computation */
2320 new_tc0->rcv_las = new_tc0->rcv_nxt;
2322 /* Notify app that we have connection. If session layer can't
2323 * allocate session send reset */
2324 if (session_stream_connect_notify (&new_tc0->connection, 0))
2326 clib_warning ("connect notify fail");
2327 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2328 tcp_connection_cleanup (new_tc0);
2332 /* Make sure after data segment processing ACK is sent */
2333 new_tc0->flags |= TCP_CONN_SNDACK;
2335 /* Update rtt with the syn-ack sample */
2336 tcp_update_rtt (new_tc0, vnet_buffer (b0)->tcp.ack_number);
2337 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2339 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2342 new_tc0->state = TCP_STATE_SYN_RCVD;
2344 /* Notify app that we have connection */
2345 if (session_stream_connect_notify (&new_tc0->connection, 0))
2347 tcp_connection_cleanup (new_tc0);
2348 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2349 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2354 tcp_init_snd_vars (tc0);
2355 tcp_make_synack (new_tc0, b0);
2356 next0 = tcp_next_output (is_ip4);
2361 /* Read data, if any */
2362 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2364 clib_warning ("rcvd data in syn-sent");
2365 error0 = tcp_segment_rcv (new_tc0, b0, &next0);
2366 if (error0 == TCP_ERROR_ACK_OK)
2367 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2368 tcp_maybe_inc_counter (syn_sent, error0, 1);
2372 tcp_make_ack (new_tc0, b0);
2373 next0 = tcp_next_output (new_tc0->c_is_ip4);
2378 b0->error = error0 ? node->errors[error0] : 0;
2380 ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2382 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2383 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2384 clib_memcpy (&t0->tcp_connection, tc0,
2385 sizeof (t0->tcp_connection));
2388 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2389 n_left_to_next, bi0, next0);
2392 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2395 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2397 tcp_inc_counter (syn_sent, TCP_ERROR_EVENT_FIFO_FULL, errors);
2398 return from_frame->n_vectors;
2402 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2403 vlib_frame_t * from_frame)
2405 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2409 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2410 vlib_frame_t * from_frame)
2412 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2416 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2418 .function = tcp4_syn_sent,
2419 .name = "tcp4-syn-sent",
2420 /* Takes a vector of packets. */
2421 .vector_size = sizeof (u32),
2422 .n_errors = TCP_N_ERROR,
2423 .error_strings = tcp_error_strings,
2424 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2427 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2428 foreach_tcp_state_next
2431 .format_trace = format_tcp_rx_trace_short,
2435 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2438 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2440 .function = tcp6_syn_sent_rcv,
2441 .name = "tcp6-syn-sent",
2442 /* Takes a vector of packets. */
2443 .vector_size = sizeof (u32),
2444 .n_errors = TCP_N_ERROR,
2445 .error_strings = tcp_error_strings,
2446 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2449 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2450 foreach_tcp_state_next
2453 .format_trace = format_tcp_rx_trace_short,
2457 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2459 vlib_node_registration_t tcp4_rcv_process_node;
2460 vlib_node_registration_t tcp6_rcv_process_node;
2463 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2464 * as per RFC793 p. 64
2467 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2468 vlib_frame_t * from_frame, int is_ip4)
2470 u32 n_left_from, next_index, *from, *to_next, n_fins = 0;
2471 u32 my_thread_index = vm->thread_index, errors = 0;
2473 from = vlib_frame_vector_args (from_frame);
2474 n_left_from = from_frame->n_vectors;
2475 next_index = node->cached_next_index;
2477 while (n_left_from > 0)
2481 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2483 while (n_left_from > 0 && n_left_to_next > 0)
2487 tcp_header_t *tcp0 = 0;
2488 tcp_connection_t *tc0;
2489 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_NONE;
2497 n_left_to_next -= 1;
2499 b0 = vlib_get_buffer (vm, bi0);
2500 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2502 if (PREDICT_FALSE (tc0 == 0))
2504 error0 = TCP_ERROR_INVALID_CONNECTION;
2508 tcp0 = tcp_buffer_hdr (b0);
2509 is_fin0 = tcp_is_fin (tcp0);
2511 /* SYNs, FINs and data consume sequence numbers */
2512 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2513 + tcp_is_syn (tcp0) + is_fin0 + vnet_buffer (b0)->tcp.data_len;
2517 tcp_connection_t *tmp;
2518 tmp = tcp_lookup_connection (tc0->c_fib_index, b0,
2519 my_thread_index, is_ip4);
2520 if (tmp->state != tc0->state)
2522 clib_warning ("state changed");
2528 * Special treatment for CLOSED
2530 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2532 error0 = TCP_ERROR_CONNECTION_CLOSED;
2537 * For all other states (except LISTEN)
2540 /* 1-4: check SEQ, RST, SYN */
2541 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, tcp0,
2544 tcp_maybe_inc_counter (rcv_process, error0, 1);
2548 /* 5: check the ACK field */
2551 case TCP_STATE_SYN_RCVD:
2553 * If the segment acknowledgment is not acceptable, form a
2555 * <SEQ=SEG.ACK><CTL=RST>
2558 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2560 TCP_DBG ("connection not accepted");
2561 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2562 error0 = TCP_ERROR_ACK_INVALID;
2566 /* Update rtt and rto */
2567 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
2569 /* Switch state to ESTABLISHED */
2570 tc0->state = TCP_STATE_ESTABLISHED;
2571 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2573 /* Initialize session variables */
2574 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2575 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2576 << tc0->rcv_opts.wscale;
2577 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2578 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2580 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2581 tcp_retransmit_timer_reset (tc0);
2582 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2583 stream_session_accept_notify (&tc0->connection);
2584 error0 = TCP_ERROR_ACK_OK;
2586 case TCP_STATE_ESTABLISHED:
2587 /* We can get packets in established state here because they
2588 * were enqueued before state change */
2589 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2591 tcp_maybe_inc_counter (rcv_process, error0, 1);
2596 case TCP_STATE_FIN_WAIT_1:
2597 /* In addition to the processing for the ESTABLISHED state, if
2598 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2599 * continue processing in that state. */
2600 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2602 tcp_maybe_inc_counter (rcv_process, error0, 1);
2606 /* Still have to send the FIN */
2607 if (tc0->flags & TCP_CONN_FINPNDG)
2609 /* TX fifo finally drained */
2610 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2613 /* If FIN is ACKed */
2614 else if (tc0->snd_una == tc0->snd_una_max)
2616 tc0->state = TCP_STATE_FIN_WAIT_2;
2617 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2619 /* Stop all retransmit timers because we have nothing more
2620 * to send. Enable waitclose though because we're willing to
2621 * wait for peer's FIN but not indefinitely. */
2622 tcp_connection_timers_reset (tc0);
2623 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2626 case TCP_STATE_FIN_WAIT_2:
2627 /* In addition to the processing for the ESTABLISHED state, if
2628 * the retransmission queue is empty, the user's CLOSE can be
2629 * acknowledged ("ok") but do not delete the TCB. */
2630 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2632 tcp_maybe_inc_counter (rcv_process, error0, 1);
2636 case TCP_STATE_CLOSE_WAIT:
2637 /* Do the same processing as for the ESTABLISHED state. */
2638 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2640 tcp_maybe_inc_counter (rcv_process, error0, 1);
2643 if (tc0->flags & TCP_CONN_FINPNDG)
2645 /* TX fifo finally drained */
2646 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2649 tcp_connection_timers_reset (tc0);
2650 tc0->state = TCP_STATE_LAST_ACK;
2651 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2656 case TCP_STATE_CLOSING:
2657 /* In addition to the processing for the ESTABLISHED state, if
2658 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2659 * otherwise ignore the segment. */
2660 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2662 tcp_maybe_inc_counter (rcv_process, error0, 1);
2666 tc0->state = TCP_STATE_TIME_WAIT;
2667 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2668 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2672 case TCP_STATE_LAST_ACK:
2673 /* The only thing that [should] arrive in this state is an
2674 * acknowledgment of our FIN. If our FIN is now acknowledged,
2675 * delete the TCB, enter the CLOSED state, and return. */
2677 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2679 error0 = TCP_ERROR_ACK_INVALID;
2682 error0 = TCP_ERROR_ACK_OK;
2683 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2684 /* Apparently our ACK for the peer's FIN was lost */
2685 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2691 tc0->state = TCP_STATE_CLOSED;
2692 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2694 /* Don't free the connection from the data path since
2695 * we can't ensure that we have no packets already enqueued
2696 * to output. Rely instead on the waitclose timer */
2697 tcp_connection_timers_reset (tc0);
2698 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, 1);
2703 case TCP_STATE_TIME_WAIT:
2704 /* The only thing that can arrive in this state is a
2705 * retransmission of the remote FIN. Acknowledge it, and restart
2706 * the 2 MSL timeout. */
2708 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2710 tcp_maybe_inc_counter (rcv_process, error0, 1);
2714 tcp_make_ack (tc0, b0);
2715 next0 = tcp_next_output (is_ip4);
2716 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2724 /* 6: check the URG bit TODO */
2726 /* 7: process the segment text */
2729 case TCP_STATE_ESTABLISHED:
2730 case TCP_STATE_FIN_WAIT_1:
2731 case TCP_STATE_FIN_WAIT_2:
2732 if (vnet_buffer (b0)->tcp.data_len)
2734 error0 = tcp_segment_rcv (tc0, b0, &next0);
2735 tcp_maybe_inc_counter (rcv_process, error0, 1);
2740 case TCP_STATE_CLOSE_WAIT:
2741 case TCP_STATE_CLOSING:
2742 case TCP_STATE_LAST_ACK:
2743 case TCP_STATE_TIME_WAIT:
2744 /* This should not occur, since a FIN has been received from the
2745 * remote side. Ignore the segment text. */
2749 /* 8: check the FIN bit */
2755 case TCP_STATE_ESTABLISHED:
2756 case TCP_STATE_SYN_RCVD:
2757 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2758 tcp_connection_timers_reset (tc0);
2759 tcp_make_fin (tc0, b0);
2761 tc0->snd_una_max = tc0->snd_nxt;
2762 tcp_retransmit_timer_set (tc0);
2763 next0 = tcp_next_output (tc0->c_is_ip4);
2764 stream_session_disconnect_notify (&tc0->connection);
2765 tc0->state = TCP_STATE_CLOSE_WAIT;
2766 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2768 case TCP_STATE_CLOSE_WAIT:
2769 case TCP_STATE_CLOSING:
2770 case TCP_STATE_LAST_ACK:
2773 case TCP_STATE_FIN_WAIT_1:
2774 tc0->state = TCP_STATE_CLOSING;
2775 tcp_make_ack (tc0, b0);
2776 next0 = tcp_next_output (is_ip4);
2777 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2778 /* Wait for ACK but not forever */
2779 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2781 case TCP_STATE_FIN_WAIT_2:
2782 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2783 tc0->state = TCP_STATE_TIME_WAIT;
2784 tcp_connection_timers_reset (tc0);
2785 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2786 tcp_make_ack (tc0, b0);
2787 next0 = tcp_next_output (is_ip4);
2788 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2790 case TCP_STATE_TIME_WAIT:
2791 /* Remain in the TIME-WAIT state. Restart the time-wait
2794 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2797 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2801 b0->error = error0 ? node->errors[error0] : 0;
2803 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2805 tcp_rx_trace_t *t0 =
2806 vlib_add_trace (vm, node, b0, sizeof (*t0));
2807 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2810 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2811 n_left_to_next, bi0, next0);
2814 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2817 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2819 tcp_inc_counter (rcv_process, TCP_ERROR_EVENT_FIFO_FULL, errors);
2820 tcp_inc_counter (rcv_process, TCP_ERROR_FIN_RCVD, n_fins);
2821 return from_frame->n_vectors;
2825 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2826 vlib_frame_t * from_frame)
2828 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2832 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2833 vlib_frame_t * from_frame)
2835 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2839 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2841 .function = tcp4_rcv_process,
2842 .name = "tcp4-rcv-process",
2843 /* Takes a vector of packets. */
2844 .vector_size = sizeof (u32),
2845 .n_errors = TCP_N_ERROR,
2846 .error_strings = tcp_error_strings,
2847 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2850 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2851 foreach_tcp_state_next
2854 .format_trace = format_tcp_rx_trace_short,
2858 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2861 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2863 .function = tcp6_rcv_process,
2864 .name = "tcp6-rcv-process",
2865 /* Takes a vector of packets. */
2866 .vector_size = sizeof (u32),
2867 .n_errors = TCP_N_ERROR,
2868 .error_strings = tcp_error_strings,
2869 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2872 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2873 foreach_tcp_state_next
2876 .format_trace = format_tcp_rx_trace_short,
2880 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2882 vlib_node_registration_t tcp4_listen_node;
2883 vlib_node_registration_t tcp6_listen_node;
2886 * LISTEN state processing as per RFC 793 p. 65
2889 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2890 vlib_frame_t * from_frame, int is_ip4)
2892 u32 n_left_from, next_index, *from, *to_next, n_syns = 0;
2893 u32 my_thread_index = vm->thread_index;
2895 from = vlib_frame_vector_args (from_frame);
2896 n_left_from = from_frame->n_vectors;
2898 next_index = node->cached_next_index;
2900 while (n_left_from > 0)
2904 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2906 while (n_left_from > 0 && n_left_to_next > 0)
2911 tcp_header_t *th0 = 0;
2912 tcp_connection_t *lc0;
2915 tcp_connection_t *child0;
2916 u32 error0 = TCP_ERROR_NONE, next0 = tcp_next_drop (is_ip4);
2923 n_left_to_next -= 1;
2925 b0 = vlib_get_buffer (vm, bi0);
2926 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2930 ip40 = vlib_buffer_get_current (b0);
2931 th0 = ip4_next_header (ip40);
2935 ip60 = vlib_buffer_get_current (b0);
2936 th0 = ip6_next_header (ip60);
2939 /* Create child session. For syn-flood protection use filter */
2941 /* 1. first check for an RST: handled in dispatch */
2942 /* if (tcp_rst (th0))
2945 /* 2. second check for an ACK: handled in dispatch */
2946 /* if (tcp_ack (th0))
2948 tcp_send_reset (b0, is_ip4);
2952 /* 3. check for a SYN (did that already) */
2954 /* Make sure connection wasn't just created */
2955 child0 = tcp_lookup_connection (lc0->c_fib_index, b0,
2956 my_thread_index, is_ip4);
2957 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
2959 error0 = TCP_ERROR_CREATE_EXISTS;
2963 /* Create child session and send SYN-ACK */
2964 child0 = tcp_connection_new (my_thread_index);
2965 child0->c_lcl_port = th0->dst_port;
2966 child0->c_rmt_port = th0->src_port;
2967 child0->c_is_ip4 = is_ip4;
2968 child0->state = TCP_STATE_SYN_RCVD;
2969 child0->c_fib_index = lc0->c_fib_index;
2973 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
2974 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
2978 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
2979 sizeof (ip6_address_t));
2980 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
2981 sizeof (ip6_address_t));
2984 if (tcp_options_parse (th0, &child0->rcv_opts))
2986 clib_warning ("options parse fail");
2990 child0->irs = vnet_buffer (b0)->tcp.seq_number;
2991 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
2992 child0->rcv_las = child0->rcv_nxt;
2993 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2995 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
2996 * segments are used to initialize PAWS. */
2997 if (tcp_opts_tstamp (&child0->rcv_opts))
2999 child0->tsval_recent = child0->rcv_opts.tsval;
3000 child0->tsval_recent_age = tcp_time_now ();
3003 if (tcp_opts_wscale (&child0->rcv_opts))
3004 child0->snd_wscale = child0->rcv_opts.wscale;
3006 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3007 << child0->snd_wscale;
3008 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3009 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3011 tcp_connection_init_vars (child0);
3012 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
3014 if (stream_session_accept (&child0->connection, lc0->c_s_index,
3017 clib_warning ("session accept fail");
3018 tcp_connection_cleanup (child0);
3019 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3023 /* Reuse buffer to make syn-ack and send */
3024 tcp_make_synack (child0, b0);
3025 next0 = tcp_next_output (is_ip4);
3026 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
3029 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3031 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3032 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3033 clib_memcpy (&t0->tcp_connection, lc0,
3034 sizeof (t0->tcp_connection));
3037 n_syns += (error0 == TCP_ERROR_NONE);
3038 b0->error = node->errors[error0];
3040 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
3041 n_left_to_next, bi0, next0);
3044 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
3047 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3048 return from_frame->n_vectors;
3052 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3053 vlib_frame_t * from_frame)
3055 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3059 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3060 vlib_frame_t * from_frame)
3062 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3066 VLIB_REGISTER_NODE (tcp4_listen_node) =
3068 .function = tcp4_listen,
3069 .name = "tcp4-listen",
3070 /* Takes a vector of packets. */
3071 .vector_size = sizeof (u32),
3072 .n_errors = TCP_N_ERROR,
3073 .error_strings = tcp_error_strings,
3074 .n_next_nodes = TCP_LISTEN_N_NEXT,
3077 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3078 foreach_tcp_state_next
3081 .format_trace = format_tcp_rx_trace_short,
3085 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
3088 VLIB_REGISTER_NODE (tcp6_listen_node) =
3090 .function = tcp6_listen,
3091 .name = "tcp6-listen",
3092 /* Takes a vector of packets. */
3093 .vector_size = sizeof (u32),
3094 .n_errors = TCP_N_ERROR,
3095 .error_strings = tcp_error_strings,
3096 .n_next_nodes = TCP_LISTEN_N_NEXT,
3099 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3100 foreach_tcp_state_next
3103 .format_trace = format_tcp_rx_trace_short,
3107 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
3109 vlib_node_registration_t tcp4_input_node;
3110 vlib_node_registration_t tcp6_input_node;
3112 typedef enum _tcp_input_next
3114 TCP_INPUT_NEXT_DROP,
3115 TCP_INPUT_NEXT_LISTEN,
3116 TCP_INPUT_NEXT_RCV_PROCESS,
3117 TCP_INPUT_NEXT_SYN_SENT,
3118 TCP_INPUT_NEXT_ESTABLISHED,
3119 TCP_INPUT_NEXT_RESET,
3120 TCP_INPUT_NEXT_PUNT,
3124 #define foreach_tcp4_input_next \
3125 _ (DROP, "ip4-drop") \
3126 _ (LISTEN, "tcp4-listen") \
3127 _ (RCV_PROCESS, "tcp4-rcv-process") \
3128 _ (SYN_SENT, "tcp4-syn-sent") \
3129 _ (ESTABLISHED, "tcp4-established") \
3130 _ (RESET, "tcp4-reset") \
3131 _ (PUNT, "ip4-punt")
3133 #define foreach_tcp6_input_next \
3134 _ (DROP, "ip6-drop") \
3135 _ (LISTEN, "tcp6-listen") \
3136 _ (RCV_PROCESS, "tcp6-rcv-process") \
3137 _ (SYN_SENT, "tcp6-syn-sent") \
3138 _ (ESTABLISHED, "tcp6-established") \
3139 _ (RESET, "tcp6-reset") \
3140 _ (PUNT, "ip6-punt")
3142 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3145 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3146 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3148 tcp_connection_t *tc;
3153 for (i = 0; i < n_bufs; i++)
3155 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3157 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3158 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3160 tcp = vlib_buffer_get_current (bs[i]);
3161 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3167 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3169 if (*error == TCP_ERROR_FILTERED)
3171 *next = TCP_INPUT_NEXT_DROP;
3173 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3175 *next = TCP_INPUT_NEXT_PUNT;
3176 *error = TCP_ERROR_PUNT;
3180 *next = TCP_INPUT_NEXT_RESET;
3181 *error = TCP_ERROR_NO_LISTENER;
3185 static inline tcp_connection_t *
3186 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3189 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3190 int n_advance_bytes, n_data_bytes;
3191 transport_connection_t *tc;
3197 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3198 tcp = ip4_next_header (ip4);
3199 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3200 n_advance_bytes = (ip4_header_bytes (ip4) + tcp_header_bytes (tcp));
3201 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3203 /* Length check. Checksum computed by ipx_local no need to compute again */
3204 if (PREDICT_FALSE (n_advance_bytes < 0))
3206 *error = TCP_ERROR_LENGTH;
3210 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3211 &ip4->src_address, tcp->dst_port,
3212 tcp->src_port, TRANSPORT_PROTO_TCP,
3213 thread_index, &is_filtered);
3217 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3218 tcp = ip6_next_header (ip6);
3219 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3220 n_advance_bytes = tcp_header_bytes (tcp);
3221 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3223 n_advance_bytes += sizeof (ip6[0]);
3225 if (PREDICT_FALSE (n_advance_bytes < 0))
3227 *error = TCP_ERROR_LENGTH;
3231 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3232 &ip6->src_address, tcp->dst_port,
3233 tcp->src_port, TRANSPORT_PROTO_TCP,
3234 thread_index, &is_filtered);
3237 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3238 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3239 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3240 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3241 vnet_buffer (b)->tcp.flags = 0;
3243 *error = is_filtered ? TCP_ERROR_FILTERED : *error;
3245 return tcp_get_connection_from_transport (tc);
3249 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3250 vlib_buffer_t * b, u16 * next, u32 * error)
3255 tcp = tcp_buffer_hdr (b);
3256 flags = tcp->flags & filter_flags;
3257 *next = tm->dispatch_table[tc->state][flags].next;
3258 *error = tm->dispatch_table[tc->state][flags].error;
3260 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3261 || *next == TCP_INPUT_NEXT_RESET))
3263 /* Overload tcp flags to store state */
3264 tcp_state_t state = tc->state;
3265 vnet_buffer (b)->tcp.flags = tc->state;
3267 if (*error == TCP_ERROR_DISPATCH)
3268 clib_warning ("disp error state %U flags %U", format_tcp_state,
3269 state, format_tcp_flags, (int) flags);
3274 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3275 vlib_frame_t * frame, int is_ip4)
3277 u32 n_left_from, *from, thread_index = vm->thread_index;
3278 tcp_main_t *tm = vnet_get_tcp_main ();
3279 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3280 u16 nexts[VLIB_FRAME_SIZE], *next;
3282 tcp_set_time_now (thread_index);
3284 from = vlib_frame_vector_args (frame);
3285 n_left_from = frame->n_vectors;
3286 vlib_get_buffers (vm, from, bufs, n_left_from);
3291 while (n_left_from >= 4)
3293 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3294 tcp_connection_t *tc0, *tc1;
3297 vlib_prefetch_buffer_header (b[2], STORE);
3298 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3300 vlib_prefetch_buffer_header (b[3], STORE);
3301 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3304 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3306 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3307 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4);
3309 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3311 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3312 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3314 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3315 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3317 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3318 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3322 if (PREDICT_TRUE (tc0 != 0))
3324 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3325 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3326 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3329 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3331 if (PREDICT_TRUE (tc1 != 0))
3333 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3334 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3335 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3338 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3345 while (n_left_from > 0)
3347 tcp_connection_t *tc0;
3348 u32 error0 = TCP_ERROR_NO_LISTENER;
3350 if (n_left_from > 1)
3352 vlib_prefetch_buffer_header (b[1], STORE);
3353 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3356 next[0] = TCP_INPUT_NEXT_DROP;
3357 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3358 if (PREDICT_TRUE (tc0 != 0))
3360 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3361 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3362 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3365 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3372 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3373 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3375 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3376 return frame->n_vectors;
3380 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3381 vlib_frame_t * from_frame)
3383 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3387 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3388 vlib_frame_t * from_frame)
3390 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3394 VLIB_REGISTER_NODE (tcp4_input_node) =
3396 .function = tcp4_input,
3397 .name = "tcp4-input",
3398 /* Takes a vector of packets. */
3399 .vector_size = sizeof (u32),
3400 .n_errors = TCP_N_ERROR,
3401 .error_strings = tcp_error_strings,
3402 .n_next_nodes = TCP_INPUT_N_NEXT,
3405 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3406 foreach_tcp4_input_next
3409 .format_buffer = format_tcp_header,
3410 .format_trace = format_tcp_rx_trace,
3414 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3417 VLIB_REGISTER_NODE (tcp6_input_node) =
3419 .function = tcp6_input,
3420 .name = "tcp6-input",
3421 /* Takes a vector of packets. */
3422 .vector_size = sizeof (u32),
3423 .n_errors = TCP_N_ERROR,
3424 .error_strings = tcp_error_strings,
3425 .n_next_nodes = TCP_INPUT_N_NEXT,
3428 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3429 foreach_tcp6_input_next
3432 .format_buffer = format_tcp_header,
3433 .format_trace = format_tcp_rx_trace,
3437 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3440 tcp_dispatch_table_init (tcp_main_t * tm)
3443 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3444 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3446 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3447 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3450 #define _(t,f,n,e) \
3452 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3453 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3456 /* SYNs for new connections -> tcp-listen. */
3457 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3458 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3459 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_RST_RCVD);
3460 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3462 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3463 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3464 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3465 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3467 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3468 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3470 /* SYN-ACK for a SYN */
3471 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3473 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3474 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3475 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3477 /* ACK for for established connection -> tcp-established. */
3478 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3479 /* FIN for for established connection -> tcp-established. */
3480 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3481 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3483 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3484 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3486 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3487 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3489 /* ACK or FIN-ACK to our FIN */
3490 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3491 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3493 /* FIN in reply to our FIN from the other side */
3494 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3495 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3496 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3497 /* FIN confirming that the peer (app) has closed */
3498 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3499 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3500 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3502 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3503 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3505 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3506 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3507 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3509 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3510 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3511 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3512 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3514 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3515 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3516 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3517 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3518 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3519 TCP_ERROR_CONNECTION_CLOSED);
3523 static clib_error_t *
3524 tcp_input_init (vlib_main_t * vm)
3526 clib_error_t *error = 0;
3527 tcp_main_t *tm = vnet_get_tcp_main ();
3529 if ((error = vlib_call_init_function (vm, tcp_init)))
3532 /* Initialize dispatch table. */
3533 tcp_dispatch_table_init (tm);
3538 VLIB_INIT_FUNCTION (tcp_input_init);
3541 * fd.io coding-style-patch-verification: ON
3544 * eval: (c-set-style "gnu")