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 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 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 *hole, *prev;
671 u32 bytes = 0, blks = 0;
674 sb->sacked_bytes = 0;
675 hole = scoreboard_last_hole (sb);
679 if (seq_gt (sb->high_sacked, hole->end))
681 bytes = sb->high_sacked - hole->end;
685 while ((prev = scoreboard_prev_hole (sb, hole))
686 && (bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
687 && blks < TCP_DUPACK_THRESHOLD))
689 bytes += hole->start - prev->end;
696 sb->lost_bytes += scoreboard_hole_bytes (hole);
699 hole = scoreboard_prev_hole (sb, hole);
701 bytes += prev->start - hole->end;
703 sb->sacked_bytes = bytes;
707 * Figure out the next hole to retransmit
709 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
711 sack_scoreboard_hole_t *
712 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
713 sack_scoreboard_hole_t * start,
715 u8 * can_rescue, u8 * snd_limited)
717 sack_scoreboard_hole_t *hole = 0;
719 hole = start ? start : scoreboard_first_hole (sb);
720 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
721 hole = scoreboard_next_hole (sb, hole);
723 /* Nothing, return */
726 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
730 /* Rule (1): if higher than rxt, less than high_sacked and lost */
731 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
733 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
737 /* Rule (2): output takes care of transmitting new data */
738 if (!have_sent_1_smss)
741 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
743 /* Rule (3): if hole not lost */
744 else if (seq_lt (hole->start, sb->high_sacked))
747 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
749 /* Rule (4): if hole beyond high_sacked */
752 ASSERT (seq_geq (hole->start, sb->high_sacked));
755 /* HighRxt MUST NOT be updated */
760 if (hole && seq_lt (sb->high_rxt, hole->start))
761 sb->high_rxt = hole->start;
767 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 seq)
769 sack_scoreboard_hole_t *hole;
770 hole = scoreboard_first_hole (sb);
773 seq = seq_gt (seq, hole->start) ? seq : hole->start;
774 sb->cur_rxt_hole = sb->head;
780 scoreboard_init (sack_scoreboard_t * sb)
782 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
783 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
784 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
788 scoreboard_clear (sack_scoreboard_t * sb)
790 sack_scoreboard_hole_t *hole;
791 while ((hole = scoreboard_first_hole (sb)))
793 scoreboard_remove_hole (sb, hole);
795 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
796 ASSERT (pool_elts (sb->holes) == 0);
797 sb->sacked_bytes = 0;
798 sb->last_sacked_bytes = 0;
799 sb->last_bytes_delivered = 0;
804 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
808 * Test that scoreboard is sane after recovery
810 * Returns 1 if scoreboard is empty or if first hole beyond
814 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
816 sack_scoreboard_hole_t *hole;
817 hole = scoreboard_first_hole (&tc->sack_sb);
818 return (!hole || seq_geq (hole->start, tc->snd_una));
822 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
824 sack_scoreboard_t *sb = &tc->sack_sb;
825 sack_block_t *blk, tmp;
826 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
827 u32 blk_index = 0, old_sacked_bytes, hole_index;
830 sb->last_sacked_bytes = 0;
831 sb->last_bytes_delivered = 0;
834 if (!tcp_opts_sack (&tc->rcv_opts)
835 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
838 old_sacked_bytes = sb->sacked_bytes;
840 /* Remove invalid blocks */
841 blk = tc->rcv_opts.sacks;
842 while (blk < vec_end (tc->rcv_opts.sacks))
844 if (seq_lt (blk->start, blk->end)
845 && seq_gt (blk->start, tc->snd_una)
846 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_una_max))
851 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
854 /* Add block for cumulative ack */
855 if (seq_gt (ack, tc->snd_una))
857 tmp.start = tc->snd_una;
859 vec_add1 (tc->rcv_opts.sacks, tmp);
862 if (vec_len (tc->rcv_opts.sacks) == 0)
865 tcp_scoreboard_trace_add (tc, ack);
867 /* Make sure blocks are ordered */
868 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
869 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
870 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
872 tmp = tc->rcv_opts.sacks[i];
873 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
874 tc->rcv_opts.sacks[j] = tmp;
877 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
879 /* If no holes, insert the first that covers all outstanding bytes */
880 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
881 tc->snd_una, tc->snd_una_max);
882 sb->tail = scoreboard_hole_index (sb, last_hole);
883 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
884 sb->high_sacked = tmp.end;
888 /* If we have holes but snd_una_max is beyond the last hole, update
890 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
891 last_hole = scoreboard_last_hole (sb);
892 if (seq_gt (tc->snd_una_max, last_hole->end))
894 if (seq_geq (last_hole->start, sb->high_sacked))
896 last_hole->end = tc->snd_una_max;
898 /* New hole after high sacked block */
899 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
901 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
905 /* Keep track of max byte sacked for when the last hole
907 if (seq_gt (tmp.end, sb->high_sacked))
908 sb->high_sacked = tmp.end;
911 /* Walk the holes with the SACK blocks */
912 hole = pool_elt_at_index (sb->holes, sb->head);
913 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
915 blk = &tc->rcv_opts.sacks[blk_index];
916 if (seq_leq (blk->start, hole->start))
918 /* Block covers hole. Remove hole */
919 if (seq_geq (blk->end, hole->end))
921 next_hole = scoreboard_next_hole (sb, hole);
923 /* Byte accounting: snd_una needs to be advanced */
928 if (seq_lt (ack, next_hole->start))
929 sb->snd_una_adv = next_hole->start - ack;
930 sb->last_bytes_delivered +=
931 next_hole->start - hole->end;
935 ASSERT (seq_geq (sb->high_sacked, ack));
936 sb->snd_una_adv = sb->high_sacked - ack;
937 sb->last_bytes_delivered += sb->high_sacked - hole->end;
941 scoreboard_remove_hole (sb, hole);
944 /* Partial 'head' overlap */
947 if (seq_gt (blk->end, hole->start))
949 hole->start = blk->end;
956 /* Hole must be split */
957 if (seq_lt (blk->end, hole->end))
959 hole_index = scoreboard_hole_index (sb, hole);
960 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
963 /* Pool might've moved */
964 hole = scoreboard_get_hole (sb, hole_index);
965 hole->end = blk->start;
967 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
969 else if (seq_lt (blk->start, hole->end))
971 hole->end = blk->start;
973 hole = scoreboard_next_hole (sb, hole);
977 scoreboard_update_bytes (tc, sb);
978 sb->last_sacked_bytes = sb->sacked_bytes
979 - (old_sacked_bytes - sb->last_bytes_delivered);
980 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
981 ASSERT (sb->sacked_bytes == 0
982 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
983 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
984 - seq_max (tc->snd_una, ack));
985 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
986 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
987 TCP_EVT_DBG (TCP_EVT_CC_SCOREBOARD, tc);
991 * Try to update snd_wnd based on feedback received from peer.
993 * If successful, and new window is 'effectively' 0, activate persist
997 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
999 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1000 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1001 if (seq_lt (tc->snd_wl1, seq)
1002 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1004 tc->snd_wnd = snd_wnd;
1007 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
1009 if (tc->snd_wnd < tc->snd_mss)
1011 /* Set persist timer if not set and we just got 0 wnd */
1012 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1013 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1014 tcp_persist_timer_set (tc);
1018 tcp_persist_timer_reset (tc);
1019 if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
1022 tcp_update_rto (tc);
1029 * Init loss recovery/fast recovery.
1031 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1032 * updated in @ref tcp_cc_handle_event after fast retransmit
1035 tcp_cc_init_congestion (tcp_connection_t * tc)
1037 tcp_fastrecovery_on (tc);
1038 tc->snd_congestion = tc->snd_una_max;
1039 tc->cwnd_acc_bytes = 0;
1040 tc->cc_algo->congestion (tc);
1041 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
1045 tcp_cc_recovery_exit (tcp_connection_t * tc)
1048 tcp_update_rto (tc);
1050 tc->snd_nxt = tc->snd_una_max;
1051 tcp_recovery_off (tc);
1052 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1056 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
1058 tc->cc_algo->recovered (tc);
1059 tc->snd_rxt_bytes = 0;
1060 tc->rcv_dupacks = 0;
1061 tc->snd_nxt = tc->snd_una_max;
1062 tcp_fastrecovery_off (tc);
1063 tcp_fastrecovery_1_smss_off (tc);
1064 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1068 tcp_cc_congestion_undo (tcp_connection_t * tc)
1070 tc->cwnd = tc->prev_cwnd;
1071 tc->ssthresh = tc->prev_ssthresh;
1072 tc->snd_nxt = tc->snd_una_max;
1073 tc->rcv_dupacks = 0;
1074 if (tcp_in_recovery (tc))
1075 tcp_cc_recovery_exit (tc);
1076 ASSERT (tc->rto_boff == 0);
1077 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
1078 /* TODO extend for fastrecovery */
1082 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1084 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1086 && tcp_opts_tstamp (&tc->rcv_opts)
1087 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1091 tcp_cc_recover (tcp_connection_t * tc)
1093 ASSERT (tcp_in_cong_recovery (tc));
1094 if (tcp_cc_is_spurious_retransmit (tc))
1096 tcp_cc_congestion_undo (tc);
1100 if (tcp_in_recovery (tc))
1101 tcp_cc_recovery_exit (tc);
1102 else if (tcp_in_fastrecovery (tc))
1103 tcp_cc_fastrecovery_exit (tc);
1105 ASSERT (tc->rto_boff == 0);
1106 ASSERT (!tcp_in_cong_recovery (tc));
1107 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1112 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
1114 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1116 /* Congestion avoidance */
1117 tc->cc_algo->rcv_ack (tc);
1118 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1120 /* If a cumulative ack, make sure dupacks is 0 */
1121 tc->rcv_dupacks = 0;
1123 /* When dupacks hits the threshold we only enter fast retransmit if
1124 * cumulative ack covers more than snd_congestion. Should snd_una
1125 * wrap this test may fail under otherwise valid circumstances.
1126 * Therefore, proactively update snd_congestion when wrap detected. */
1128 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1129 && seq_gt (tc->snd_congestion, tc->snd_una)))
1130 tc->snd_congestion = tc->snd_una - 1;
1134 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1136 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1140 tcp_should_fastrecover (tcp_connection_t * tc)
1142 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1143 || tcp_should_fastrecover_sack (tc));
1147 * One function to rule them all ... and in the darkness bind them
1150 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1154 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1156 if (tc->bytes_acked)
1158 tcp_fast_retransmit (tc);
1162 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1163 * it account for the bytes that left the network.
1165 else if (is_dack && !tcp_in_recovery (tc))
1167 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1168 ASSERT (tc->snd_una != tc->snd_una_max
1169 || tc->sack_sb.last_sacked_bytes);
1173 /* Pure duplicate ack. If some data got acked, it's handled lower */
1174 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1176 ASSERT (tcp_in_fastrecovery (tc));
1177 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1180 else if (tcp_should_fastrecover (tc))
1182 ASSERT (!tcp_in_fastrecovery (tc));
1184 /* If of of the two conditions lower hold, reset dupacks because
1185 * we're probably after timeout (RFC6582 heuristics).
1186 * If Cumulative ack does not cover more than congestion threshold,
1188 * 1) The following doesn't hold: The congestion window is greater
1189 * than SMSS bytes and the difference between highest_ack
1190 * and prev_highest_ack is at most 4*SMSS bytes
1191 * 2) Echoed timestamp in the last non-dup ack does not equal the
1194 if (seq_leq (tc->snd_una, tc->snd_congestion)
1195 && ((!(tc->cwnd > tc->snd_mss
1196 && tc->bytes_acked <= 4 * tc->snd_mss))
1197 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1199 tc->rcv_dupacks = 0;
1203 tcp_cc_init_congestion (tc);
1204 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1206 /* The first segment MUST be retransmitted */
1207 tcp_retransmit_first_unacked (tc);
1209 /* Post retransmit update cwnd to ssthresh and account for the
1210 * three segments that have left the network and should've been
1211 * buffered at the receiver XXX */
1212 tc->cwnd = tc->ssthresh + tc->rcv_dupacks * tc->snd_mss;
1213 ASSERT (tc->cwnd >= tc->snd_mss);
1215 /* If cwnd allows, send more data */
1216 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1218 scoreboard_init_high_rxt (&tc->sack_sb,
1219 tc->snd_una + tc->snd_mss);
1220 tcp_fast_retransmit_sack (tc);
1224 tcp_fast_retransmit_no_sack (tc);
1228 else if (!tc->bytes_acked
1229 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1231 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1238 if (!tc->bytes_acked)
1242 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1245 * Legitimate ACK. 1) See if we can exit recovery
1247 /* XXX limit this only to first partial ack? */
1248 if (seq_lt (tc->snd_una, tc->snd_congestion))
1249 tcp_retransmit_timer_force_update (tc);
1251 tcp_retransmit_timer_update (tc);
1253 if (seq_geq (tc->snd_una, tc->snd_congestion))
1255 /* If spurious return, we've already updated everything */
1256 if (tcp_cc_recover (tc))
1258 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1262 tc->snd_nxt = tc->snd_una_max;
1264 /* Treat as congestion avoidance ack */
1265 tc->cc_algo->rcv_ack (tc);
1266 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1271 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1274 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1275 * reset dupacks to 0. Also needed if in congestion recovery */
1276 tc->rcv_dupacks = 0;
1278 /* Post RTO timeout don't try anything fancy */
1279 if (tcp_in_recovery (tc))
1281 tc->cc_algo->rcv_ack (tc);
1282 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1283 transport_add_tx_event (&tc->connection);
1287 /* Remove retransmitted bytes that have been delivered */
1288 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1289 >= tc->sack_sb.last_bytes_delivered
1290 || (tc->flags & TCP_CONN_FINSNT));
1292 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1294 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1295 * remove sacked bytes delivered */
1296 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1297 - tc->sack_sb.last_bytes_delivered;
1298 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1299 tc->snd_rxt_bytes -= rxt_delivered;
1303 /* Either all retransmitted holes have been acked, or we're
1304 * "in the blind" and retransmitting segment by segment */
1305 tc->snd_rxt_bytes = 0;
1308 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1311 * Since this was a partial ack, try to retransmit some more data
1313 tcp_fast_retransmit (tc);
1317 * Process incoming ACK
1320 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
1321 tcp_header_t * th, u32 * next, u32 * error)
1323 u32 prev_snd_wnd, prev_snd_una;
1326 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1328 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1329 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1331 /* When we entered recovery, we reset snd_nxt to snd_una. Seems peer
1332 * still has the data so accept the ack */
1333 if (tcp_in_recovery (tc)
1334 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_congestion))
1336 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1337 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
1338 tc->snd_una_max = tc->snd_nxt;
1342 /* If we have outstanding data and this is within the window, accept it,
1343 * probably retransmit has timed out. Otherwise ACK segment and then
1345 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1347 tcp_make_ack (tc, b);
1348 *next = tcp_next_output (tc->c_is_ip4);
1349 *error = TCP_ERROR_ACK_INVALID;
1350 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1351 vnet_buffer (b)->tcp.ack_number);
1355 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1356 vnet_buffer (b)->tcp.ack_number);
1358 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1359 *error = TCP_ERROR_ACK_FUTURE;
1362 /* If old ACK, probably it's an old dupack */
1363 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1365 *error = TCP_ERROR_ACK_OLD;
1366 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1367 vnet_buffer (b)->tcp.ack_number);
1368 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1369 tcp_cc_handle_event (tc, 1);
1370 /* Don't drop yet */
1375 * Looks okay, process feedback
1378 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1379 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1381 prev_snd_wnd = tc->snd_wnd;
1382 prev_snd_una = tc->snd_una;
1383 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1384 vnet_buffer (b)->tcp.ack_number,
1385 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1386 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1387 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1388 tcp_validate_txf_size (tc, tc->bytes_acked);
1390 if (tc->bytes_acked)
1391 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
1393 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1396 * Check if we have congestion event
1399 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1401 tcp_cc_handle_event (tc, is_dack);
1402 if (!tcp_in_cong_recovery (tc))
1404 *error = TCP_ERROR_ACK_DUP;
1405 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1411 * Update congestion control (slow start/congestion avoidance)
1413 tcp_cc_update (tc, b);
1414 *error = TCP_ERROR_ACK_OK;
1419 tcp_sack_vector_is_sane (sack_block_t * sacks)
1422 for (i = 1; i < vec_len (sacks); i++)
1424 if (sacks[i - 1].end == sacks[i].start)
1431 * Build SACK list as per RFC2018.
1433 * Makes sure the first block contains the segment that generated the current
1434 * ACK and the following ones are the ones most recently reported in SACK
1437 * @param tc TCP connection for which the SACK list is updated
1438 * @param start Start sequence number of the newest SACK block
1439 * @param end End sequence of the newest SACK block
1442 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1444 sack_block_t *new_list = 0, *block = 0;
1447 /* If the first segment is ooo add it to the list. Last write might've moved
1448 * rcv_nxt over the first segment. */
1449 if (seq_lt (tc->rcv_nxt, start))
1451 vec_add2 (new_list, block, 1);
1452 block->start = start;
1456 /* Find the blocks still worth keeping. */
1457 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1459 /* Discard if rcv_nxt advanced beyond current block */
1460 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1463 /* Merge or drop if segment overlapped by the new segment */
1464 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1465 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1467 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1468 new_list[0].start = tc->snd_sacks[i].start;
1469 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1470 new_list[0].end = tc->snd_sacks[i].end;
1474 /* Save to new SACK list if we have space. */
1475 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1477 vec_add1 (new_list, tc->snd_sacks[i]);
1481 clib_warning ("sack discarded");
1485 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1487 /* Replace old vector with new one */
1488 vec_free (tc->snd_sacks);
1489 tc->snd_sacks = new_list;
1491 /* Segments should not 'touch' */
1492 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1496 tcp_sack_list_bytes (tcp_connection_t * tc)
1499 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1500 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1504 /** Enqueue data for delivery to application */
1506 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1509 int written, error = TCP_ERROR_ENQUEUED;
1511 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1513 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1514 1 /* queue event */ , 1);
1516 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1518 /* Update rcv_nxt */
1519 if (PREDICT_TRUE (written == data_len))
1521 tc->rcv_nxt += written;
1523 /* If more data written than expected, account for out-of-order bytes. */
1524 else if (written > data_len)
1526 tc->rcv_nxt += written;
1528 /* Send ACK confirming the update */
1529 tc->flags |= TCP_CONN_SNDACK;
1530 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1532 else if (written > 0)
1534 /* We've written something but FIFO is probably full now */
1535 tc->rcv_nxt += written;
1537 /* Depending on how fast the app is, all remaining buffers in burst will
1538 * not be enqueued. Inform peer */
1539 tc->flags |= TCP_CONN_SNDACK;
1541 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1545 tc->flags |= TCP_CONN_SNDACK;
1546 return TCP_ERROR_FIFO_FULL;
1549 /* Update SACK list if need be */
1550 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1552 /* Remove SACK blocks that have been delivered */
1553 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1559 /** Enqueue out-of-order data */
1561 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1564 stream_session_t *s0;
1567 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1570 /* Enqueue out-of-order data with relative offset */
1571 rv = session_enqueue_stream_connection (&tc->connection, b,
1572 vnet_buffer (b)->tcp.seq_number -
1573 tc->rcv_nxt, 0 /* queue event */ ,
1576 /* Nothing written */
1579 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1580 return TCP_ERROR_FIFO_FULL;
1583 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1585 /* Update SACK list if in use */
1586 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1588 ooo_segment_t *newest;
1591 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1593 /* Get the newest segment from the fifo */
1594 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1597 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1598 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1599 start = tc->rcv_nxt + offset;
1600 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1601 tcp_update_sack_list (tc, start, end);
1602 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1603 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1607 return TCP_ERROR_ENQUEUED_OOO;
1611 * Check if ACK could be delayed. If ack can be delayed, it should return
1612 * true for a full frame. If we're always acking return 0.
1615 tcp_can_delack (tcp_connection_t * tc)
1617 /* Send ack if ... */
1619 /* just sent a rcv wnd 0 */
1620 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1621 /* constrained to send ack */
1622 || (tc->flags & TCP_CONN_SNDACK) != 0
1623 /* we're almost out of tx wnd */
1624 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1631 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1633 u32 discard, first = b->current_length;
1634 vlib_main_t *vm = vlib_get_main ();
1636 /* Handle multi-buffer segments */
1637 if (n_bytes_to_drop > b->current_length)
1639 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1643 discard = clib_min (n_bytes_to_drop, b->current_length);
1644 vlib_buffer_advance (b, discard);
1645 b = vlib_get_buffer (vm, b->next_buffer);
1646 n_bytes_to_drop -= discard;
1648 while (n_bytes_to_drop);
1649 if (n_bytes_to_drop > first)
1650 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1653 vlib_buffer_advance (b, n_bytes_to_drop);
1654 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1659 * Receive buffer for connection and handle acks
1661 * It handles both in order or out-of-order data.
1664 tcp_segment_rcv (tcp_connection_t * tc, vlib_buffer_t * b, u32 * next0)
1666 u32 error, n_bytes_to_drop, n_data_bytes;
1668 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1669 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1670 ASSERT (n_data_bytes);
1672 /* Handle out-of-order data */
1673 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1675 /* Old sequence numbers allowed through because they overlapped
1677 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1679 /* Completely in the past (possible retransmit). Ack
1680 * retransmissions since we may not have any data to send */
1681 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1683 tcp_make_ack (tc, b);
1684 error = TCP_ERROR_SEGMENT_OLD;
1685 *next0 = tcp_next_output (tc->c_is_ip4);
1689 /* Chop off the bytes in the past and see if what is left
1690 * can be enqueued in order */
1691 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1692 n_data_bytes -= n_bytes_to_drop;
1693 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1694 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1696 error = TCP_ERROR_SEGMENT_OLD;
1697 *next0 = tcp_next_drop (tc->c_is_ip4);
1703 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1704 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1705 *next0 = tcp_next_output (tc->c_is_ip4);
1706 tcp_make_ack (tc, b);
1707 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1708 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1714 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1715 * segments can be enqueued after fifo tail offset changes. */
1716 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1717 if (tcp_can_delack (tc))
1719 *next0 = tcp_next_drop (tc->c_is_ip4);
1720 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1721 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1725 *next0 = tcp_next_output (tc->c_is_ip4);
1726 tcp_make_ack (tc, b);
1734 tcp_header_t tcp_header;
1735 tcp_connection_t tcp_connection;
1739 format_tcp_rx_trace (u8 * s, va_list * args)
1741 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1742 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1743 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1744 u32 indent = format_get_indent (s);
1746 s = format (s, "%U\n%U%U",
1747 format_tcp_header, &t->tcp_header, 128,
1748 format_white_space, indent,
1749 format_tcp_connection, &t->tcp_connection, 1);
1755 format_tcp_rx_trace_short (u8 * s, va_list * args)
1757 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1758 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1759 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1761 s = format (s, "%d -> %d (%U)",
1762 clib_net_to_host_u16 (t->tcp_header.dst_port),
1763 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
1764 t->tcp_connection.state);
1770 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1771 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1775 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1779 th0 = tcp_buffer_hdr (b0);
1781 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1785 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
1786 vlib_frame_t * frame, u8 is_ip4)
1790 n_left = frame->n_vectors;
1791 from = vlib_frame_vector_args (frame);
1795 tcp_connection_t *tc0;
1802 b0 = vlib_get_buffer (vm, bi0);
1804 if (b0->flags & VLIB_BUFFER_IS_TRACED)
1806 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1807 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1809 th0 = tcp_buffer_hdr (b0);
1810 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1819 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
1820 u8 is_ip4, u32 evt, u32 val)
1823 vlib_node_increment_counter (vm, tcp4_node, evt, val);
1825 vlib_node_increment_counter (vm, tcp6_node, evt, val);
1828 #define tcp_maybe_inc_counter(node_id, err, count) \
1830 if (next0 != tcp_next_drop (is_ip4)) \
1831 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1832 tcp6_##node_id##_node.index, is_ip4, err, \
1835 #define tcp_inc_counter(node_id, err, count) \
1836 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1837 tcp6_##node_id##_node.index, is_ip4, \
1839 #define tcp_maybe_inc_err_counter(cnts, err) \
1841 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
1843 #define tcp_inc_err_counter(cnts, err, val) \
1847 #define tcp_store_err_counters(node_id, cnts) \
1850 for (i = 0; i < TCP_N_ERROR; i++) \
1852 tcp_inc_counter(node_id, i, cnts[i]); \
1857 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1858 vlib_frame_t * frame, int is_ip4)
1860 u32 thread_index = vm->thread_index, errors = 0;
1861 u32 n_left_from, next_index, *from, *to_next;
1862 u16 err_counters[TCP_N_ERROR] = { 0 };
1865 if (node->flags & VLIB_NODE_FLAG_TRACE)
1866 tcp_established_trace_frame (vm, node, frame, is_ip4);
1868 from = vlib_frame_vector_args (frame);
1869 n_left_from = frame->n_vectors;
1870 next_index = node->cached_next_index;
1872 while (n_left_from > 0)
1876 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1877 while (n_left_from > 0 && n_left_to_next > 0)
1881 tcp_header_t *th0 = 0;
1882 tcp_connection_t *tc0;
1883 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ACK_OK;
1885 if (n_left_from > 1)
1888 pb = vlib_get_buffer (vm, from[1]);
1889 vlib_prefetch_buffer_header (pb, LOAD);
1890 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
1898 n_left_to_next -= 1;
1900 b0 = vlib_get_buffer (vm, bi0);
1901 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1904 if (PREDICT_FALSE (tc0 == 0))
1906 error0 = TCP_ERROR_INVALID_CONNECTION;
1910 th0 = tcp_buffer_hdr (b0);
1911 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
1912 * dangling reference. */
1913 is_fin = tcp_is_fin (th0);
1915 /* SYNs, FINs and data consume sequence numbers */
1916 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1917 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
1919 /* TODO header prediction fast path */
1921 /* 1-4: check SEQ, RST, SYN */
1922 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0,
1925 tcp_maybe_inc_err_counter (err_counters, error0);
1926 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
1930 /* 5: check the ACK field */
1931 if (PREDICT_FALSE (tcp_rcv_ack (tc0, b0, th0, &next0, &error0)))
1933 tcp_maybe_inc_err_counter (err_counters, error0);
1937 /* 6: check the URG bit TODO */
1939 /* 7: process the segment text */
1940 if (vnet_buffer (b0)->tcp.data_len)
1942 error0 = tcp_segment_rcv (tc0, b0, &next0);
1943 tcp_maybe_inc_err_counter (err_counters, error0);
1946 /* 8: check the FIN bit */
1947 if (PREDICT_FALSE (is_fin))
1949 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1950 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1951 /* Account for the FIN if nothing else was received */
1952 if (vnet_buffer (b0)->tcp.data_len == 0)
1954 tcp_make_ack (tc0, b0);
1955 next0 = tcp_next_output (tc0->c_is_ip4);
1956 tc0->state = TCP_STATE_CLOSE_WAIT;
1957 stream_session_disconnect_notify (&tc0->connection);
1958 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1959 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1960 tcp_inc_err_counter (err_counters, TCP_ERROR_FIN_RCVD, 1);
1964 b0->error = node->errors[error0];
1965 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1966 n_left_to_next, bi0, next0);
1969 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1972 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
1974 err_counters[TCP_ERROR_EVENT_FIFO_FULL] = errors;
1975 tcp_store_err_counters (established, err_counters);
1976 tcp_flush_frame_to_output (vm, thread_index, is_ip4);
1978 return frame->n_vectors;
1982 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1983 vlib_frame_t * from_frame)
1985 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1989 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1990 vlib_frame_t * from_frame)
1992 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1996 VLIB_REGISTER_NODE (tcp4_established_node) =
1998 .function = tcp4_established,
1999 .name = "tcp4-established",
2000 /* Takes a vector of packets. */
2001 .vector_size = sizeof (u32),
2002 .n_errors = TCP_N_ERROR,
2003 .error_strings = tcp_error_strings,
2004 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2007 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2008 foreach_tcp_state_next
2011 .format_trace = format_tcp_rx_trace_short,
2015 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
2018 VLIB_REGISTER_NODE (tcp6_established_node) =
2020 .function = tcp6_established,
2021 .name = "tcp6-established",
2022 /* Takes a vector of packets. */
2023 .vector_size = sizeof (u32),
2024 .n_errors = TCP_N_ERROR,
2025 .error_strings = tcp_error_strings,
2026 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2029 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2030 foreach_tcp_state_next
2033 .format_trace = format_tcp_rx_trace_short,
2038 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
2040 vlib_node_registration_t tcp4_syn_sent_node;
2041 vlib_node_registration_t tcp6_syn_sent_node;
2044 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2046 transport_connection_t *tmp = 0;
2053 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2056 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2057 && (tc->state == TCP_STATE_LISTEN
2058 || tc->c_rmt_port == hdr->src_port));
2062 handle = session_lookup_half_open_handle (&tc->connection);
2063 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2064 tc->c_proto, tc->c_is_ip4);
2068 if (tmp->lcl_port == hdr->dst_port
2069 && tmp->rmt_port == hdr->src_port)
2071 TCP_DBG ("half-open is valid!");
2079 * Lookup transport connection
2081 static tcp_connection_t *
2082 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2086 transport_connection_t *tconn;
2087 tcp_connection_t *tc;
2092 ip4 = vlib_buffer_get_current (b);
2093 tcp = ip4_next_header (ip4);
2094 tconn = session_lookup_connection_wt4 (fib_index,
2099 TRANSPORT_PROTO_TCP,
2100 thread_index, &is_filtered);
2101 tc = tcp_get_connection_from_transport (tconn);
2102 ASSERT (tcp_lookup_is_valid (tc, tcp));
2107 ip6 = vlib_buffer_get_current (b);
2108 tcp = ip6_next_header (ip6);
2109 tconn = session_lookup_connection_wt6 (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));
2123 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2124 vlib_frame_t * from_frame, int is_ip4)
2126 tcp_main_t *tm = vnet_get_tcp_main ();
2127 u32 n_left_from, next_index, *from, *to_next;
2128 u32 my_thread_index = vm->thread_index, errors = 0;
2130 from = vlib_frame_vector_args (from_frame);
2131 n_left_from = from_frame->n_vectors;
2133 next_index = node->cached_next_index;
2135 while (n_left_from > 0)
2139 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2141 while (n_left_from > 0 && n_left_to_next > 0)
2143 u32 bi0, ack0, seq0;
2146 tcp_header_t *tcp0 = 0;
2147 tcp_connection_t *tc0;
2148 tcp_connection_t *new_tc0;
2149 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ENQUEUED;
2156 n_left_to_next -= 1;
2158 b0 = vlib_get_buffer (vm, bi0);
2160 tcp_half_open_connection_get (vnet_buffer (b0)->
2161 tcp.connection_index);
2162 if (PREDICT_FALSE (tc0 == 0))
2164 error0 = TCP_ERROR_INVALID_CONNECTION;
2168 /* Half-open completed recently but the connection was't removed
2169 * yet by the owning thread */
2170 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2172 /* Make sure the connection actually exists */
2173 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2174 my_thread_index, is_ip4));
2178 ack0 = vnet_buffer (b0)->tcp.ack_number;
2179 seq0 = vnet_buffer (b0)->tcp.seq_number;
2180 tcp0 = tcp_buffer_hdr (b0);
2182 /* Crude check to see if the connection handle does not match
2183 * the packet. Probably connection just switched to established */
2184 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2185 || tcp0->src_port != tc0->c_rmt_port))
2189 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
2192 /* SYNs, FINs and data consume sequence numbers */
2193 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
2194 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
2197 * 1. check the ACK bit
2201 * If the ACK bit is set
2202 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2203 * the RST bit is set, if so drop the segment and return)
2204 * <SEQ=SEG.ACK><CTL=RST>
2205 * and discard the segment. Return.
2206 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2210 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2212 clib_warning ("ack not in rcv wnd");
2213 if (!tcp_rst (tcp0))
2214 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2218 /* Make sure ACK is valid */
2219 if (seq_gt (tc0->snd_una, ack0))
2221 clib_warning ("ack invalid");
2227 * 2. check the RST bit
2232 /* If ACK is acceptable, signal client that peer is not
2233 * willing to accept connection and drop connection*/
2235 tcp_connection_reset (tc0);
2240 * 3. check the security and precedence (skipped)
2244 * 4. check the SYN bit
2247 /* No SYN flag. Drop. */
2248 if (!tcp_syn (tcp0))
2250 clib_warning ("not synack");
2255 if (tcp_options_parse (tcp0, &tc0->rcv_opts))
2257 clib_warning ("options parse fail");
2261 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2262 * current thread pool. */
2263 pool_get (tm->connections[my_thread_index], new_tc0);
2264 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
2265 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2266 new_tc0->c_thread_index = my_thread_index;
2267 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2268 new_tc0->irs = seq0;
2269 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
2270 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] =
2271 TCP_TIMER_HANDLE_INVALID;
2272 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2274 /* If this is not the owning thread, wait for syn retransmit to
2275 * expire and cleanup then */
2276 if (tcp_half_open_connection_cleanup (tc0))
2277 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2279 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2281 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2282 new_tc0->tsval_recent_age = tcp_time_now ();
2285 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2286 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2288 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2289 << new_tc0->snd_wscale;
2290 new_tc0->snd_wl1 = seq0;
2291 new_tc0->snd_wl2 = ack0;
2293 tcp_connection_init_vars (new_tc0);
2295 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2296 if (PREDICT_TRUE (tcp_ack (tcp0)))
2298 /* Our SYN is ACKed: we have iss < ack = snd_una */
2300 /* TODO Dequeue acknowledged segments if we support Fast Open */
2301 new_tc0->snd_una = ack0;
2302 new_tc0->state = TCP_STATE_ESTABLISHED;
2304 /* Make sure las is initialized for the wnd computation */
2305 new_tc0->rcv_las = new_tc0->rcv_nxt;
2307 /* Notify app that we have connection. If session layer can't
2308 * allocate session send reset */
2309 if (session_stream_connect_notify (&new_tc0->connection, 0))
2311 clib_warning ("connect notify fail");
2312 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2313 tcp_connection_cleanup (new_tc0);
2317 /* Make sure after data segment processing ACK is sent */
2318 new_tc0->flags |= TCP_CONN_SNDACK;
2320 /* Update rtt with the syn-ack sample */
2321 tcp_update_rtt (new_tc0, vnet_buffer (b0)->tcp.ack_number);
2322 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2324 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2327 new_tc0->state = TCP_STATE_SYN_RCVD;
2329 /* Notify app that we have connection */
2330 if (session_stream_connect_notify (&new_tc0->connection, 0))
2332 tcp_connection_cleanup (new_tc0);
2333 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2334 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2339 tcp_init_snd_vars (tc0);
2340 tcp_make_synack (new_tc0, b0);
2341 next0 = tcp_next_output (is_ip4);
2346 /* Read data, if any */
2347 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2349 clib_warning ("rcvd data in syn-sent");
2350 error0 = tcp_segment_rcv (new_tc0, b0, &next0);
2351 if (error0 == TCP_ERROR_ACK_OK)
2352 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2353 tcp_maybe_inc_counter (syn_sent, error0, 1);
2357 tcp_make_ack (new_tc0, b0);
2358 next0 = tcp_next_output (new_tc0->c_is_ip4);
2363 b0->error = error0 ? node->errors[error0] : 0;
2365 ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2367 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2368 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2369 clib_memcpy (&t0->tcp_connection, tc0,
2370 sizeof (t0->tcp_connection));
2373 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2374 n_left_to_next, bi0, next0);
2377 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2380 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2382 tcp_inc_counter (syn_sent, TCP_ERROR_EVENT_FIFO_FULL, errors);
2383 return from_frame->n_vectors;
2387 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2388 vlib_frame_t * from_frame)
2390 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2394 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2395 vlib_frame_t * from_frame)
2397 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2401 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2403 .function = tcp4_syn_sent,
2404 .name = "tcp4-syn-sent",
2405 /* Takes a vector of packets. */
2406 .vector_size = sizeof (u32),
2407 .n_errors = TCP_N_ERROR,
2408 .error_strings = tcp_error_strings,
2409 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2412 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2413 foreach_tcp_state_next
2416 .format_trace = format_tcp_rx_trace_short,
2420 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2423 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2425 .function = tcp6_syn_sent_rcv,
2426 .name = "tcp6-syn-sent",
2427 /* Takes a vector of packets. */
2428 .vector_size = sizeof (u32),
2429 .n_errors = TCP_N_ERROR,
2430 .error_strings = tcp_error_strings,
2431 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2434 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2435 foreach_tcp_state_next
2438 .format_trace = format_tcp_rx_trace_short,
2442 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2444 vlib_node_registration_t tcp4_rcv_process_node;
2445 vlib_node_registration_t tcp6_rcv_process_node;
2448 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2449 * as per RFC793 p. 64
2452 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2453 vlib_frame_t * from_frame, int is_ip4)
2455 u32 n_left_from, next_index, *from, *to_next, n_fins = 0;
2456 u32 my_thread_index = vm->thread_index, errors = 0;
2458 from = vlib_frame_vector_args (from_frame);
2459 n_left_from = from_frame->n_vectors;
2460 next_index = node->cached_next_index;
2462 while (n_left_from > 0)
2466 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2468 while (n_left_from > 0 && n_left_to_next > 0)
2472 tcp_header_t *tcp0 = 0;
2473 tcp_connection_t *tc0;
2474 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_NONE;
2482 n_left_to_next -= 1;
2484 b0 = vlib_get_buffer (vm, bi0);
2485 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2487 if (PREDICT_FALSE (tc0 == 0))
2489 error0 = TCP_ERROR_INVALID_CONNECTION;
2493 tcp0 = tcp_buffer_hdr (b0);
2494 is_fin0 = tcp_is_fin (tcp0);
2496 /* SYNs, FINs and data consume sequence numbers */
2497 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2498 + tcp_is_syn (tcp0) + is_fin0 + vnet_buffer (b0)->tcp.data_len;
2502 tcp_connection_t *tmp;
2503 tmp = tcp_lookup_connection (tc0->c_fib_index, b0,
2504 my_thread_index, is_ip4);
2505 if (tmp->state != tc0->state)
2507 clib_warning ("state changed");
2513 * Special treatment for CLOSED
2515 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2517 error0 = TCP_ERROR_CONNECTION_CLOSED;
2522 * For all other states (except LISTEN)
2525 /* 1-4: check SEQ, RST, SYN */
2526 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, tcp0,
2529 tcp_maybe_inc_counter (rcv_process, error0, 1);
2533 /* 5: check the ACK field */
2536 case TCP_STATE_SYN_RCVD:
2538 * If the segment acknowledgment is not acceptable, form a
2540 * <SEQ=SEG.ACK><CTL=RST>
2543 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2545 TCP_DBG ("connection not accepted");
2546 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2547 error0 = TCP_ERROR_ACK_INVALID;
2551 /* Update rtt and rto */
2552 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
2554 /* Switch state to ESTABLISHED */
2555 tc0->state = TCP_STATE_ESTABLISHED;
2556 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2558 /* Initialize session variables */
2559 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2560 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2561 << tc0->rcv_opts.wscale;
2562 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2563 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2565 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2566 tcp_retransmit_timer_reset (tc0);
2567 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2568 stream_session_accept_notify (&tc0->connection);
2569 error0 = TCP_ERROR_ACK_OK;
2571 case TCP_STATE_ESTABLISHED:
2572 /* We can get packets in established state here because they
2573 * were enqueued before state change */
2574 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2576 tcp_maybe_inc_counter (rcv_process, error0, 1);
2581 case TCP_STATE_FIN_WAIT_1:
2582 /* In addition to the processing for the ESTABLISHED state, if
2583 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2584 * continue processing in that state. */
2585 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2587 tcp_maybe_inc_counter (rcv_process, error0, 1);
2591 /* Still have to send the FIN */
2592 if (tc0->flags & TCP_CONN_FINPNDG)
2594 /* TX fifo finally drained */
2595 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2598 /* If FIN is ACKed */
2599 else if (tc0->snd_una == tc0->snd_una_max)
2601 tc0->state = TCP_STATE_FIN_WAIT_2;
2602 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2604 /* Stop all retransmit timers because we have nothing more
2605 * to send. Enable waitclose though because we're willing to
2606 * wait for peer's FIN but not indefinitely. */
2607 tcp_connection_timers_reset (tc0);
2608 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2611 case TCP_STATE_FIN_WAIT_2:
2612 /* In addition to the processing for the ESTABLISHED state, if
2613 * the retransmission queue is empty, the user's CLOSE can be
2614 * acknowledged ("ok") but do not delete the TCB. */
2615 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2617 tcp_maybe_inc_counter (rcv_process, error0, 1);
2621 case TCP_STATE_CLOSE_WAIT:
2622 /* Do the same processing as for the ESTABLISHED state. */
2623 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2625 tcp_maybe_inc_counter (rcv_process, error0, 1);
2628 if (tc0->flags & TCP_CONN_FINPNDG)
2630 /* TX fifo finally drained */
2631 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2634 tcp_connection_timers_reset (tc0);
2635 tc0->state = TCP_STATE_LAST_ACK;
2636 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2641 case TCP_STATE_CLOSING:
2642 /* In addition to the processing for the ESTABLISHED state, if
2643 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2644 * otherwise ignore the segment. */
2645 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2647 tcp_maybe_inc_counter (rcv_process, error0, 1);
2651 tc0->state = TCP_STATE_TIME_WAIT;
2652 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2653 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2657 case TCP_STATE_LAST_ACK:
2658 /* The only thing that [should] arrive in this state is an
2659 * acknowledgment of our FIN. If our FIN is now acknowledged,
2660 * delete the TCB, enter the CLOSED state, and return. */
2662 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2664 error0 = TCP_ERROR_ACK_INVALID;
2667 error0 = TCP_ERROR_ACK_OK;
2668 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2669 /* Apparently our ACK for the peer's FIN was lost */
2670 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2676 tc0->state = TCP_STATE_CLOSED;
2677 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2678 /* Delete the connection/session since the pipes should be
2680 tcp_connection_del (tc0);
2685 case TCP_STATE_TIME_WAIT:
2686 /* The only thing that can arrive in this state is a
2687 * retransmission of the remote FIN. Acknowledge it, and restart
2688 * the 2 MSL timeout. */
2690 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2692 tcp_maybe_inc_counter (rcv_process, error0, 1);
2696 tcp_make_ack (tc0, b0);
2697 next0 = tcp_next_output (is_ip4);
2698 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2706 /* 6: check the URG bit TODO */
2708 /* 7: process the segment text */
2711 case TCP_STATE_ESTABLISHED:
2712 case TCP_STATE_FIN_WAIT_1:
2713 case TCP_STATE_FIN_WAIT_2:
2714 if (vnet_buffer (b0)->tcp.data_len)
2716 error0 = tcp_segment_rcv (tc0, b0, &next0);
2717 tcp_maybe_inc_counter (rcv_process, error0, 1);
2722 case TCP_STATE_CLOSE_WAIT:
2723 case TCP_STATE_CLOSING:
2724 case TCP_STATE_LAST_ACK:
2725 case TCP_STATE_TIME_WAIT:
2726 /* This should not occur, since a FIN has been received from the
2727 * remote side. Ignore the segment text. */
2731 /* 8: check the FIN bit */
2737 case TCP_STATE_ESTABLISHED:
2738 case TCP_STATE_SYN_RCVD:
2739 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2740 tcp_connection_timers_reset (tc0);
2741 tcp_make_fin (tc0, b0);
2743 tc0->snd_una_max = tc0->snd_nxt;
2744 tcp_retransmit_timer_set (tc0);
2745 next0 = tcp_next_output (tc0->c_is_ip4);
2746 stream_session_disconnect_notify (&tc0->connection);
2747 tc0->state = TCP_STATE_CLOSE_WAIT;
2748 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2750 case TCP_STATE_CLOSE_WAIT:
2751 case TCP_STATE_CLOSING:
2752 case TCP_STATE_LAST_ACK:
2755 case TCP_STATE_FIN_WAIT_1:
2756 tc0->state = TCP_STATE_CLOSING;
2757 tcp_make_ack (tc0, b0);
2758 next0 = tcp_next_output (is_ip4);
2759 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2760 /* Wait for ACK but not forever */
2761 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2763 case TCP_STATE_FIN_WAIT_2:
2764 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2765 tc0->state = TCP_STATE_TIME_WAIT;
2766 tcp_connection_timers_reset (tc0);
2767 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2768 tcp_make_ack (tc0, b0);
2769 next0 = tcp_next_output (is_ip4);
2770 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2772 case TCP_STATE_TIME_WAIT:
2773 /* Remain in the TIME-WAIT state. Restart the time-wait
2776 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2779 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2783 b0->error = error0 ? node->errors[error0] : 0;
2785 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2787 tcp_rx_trace_t *t0 =
2788 vlib_add_trace (vm, node, b0, sizeof (*t0));
2789 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2792 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2793 n_left_to_next, bi0, next0);
2796 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2799 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2801 tcp_inc_counter (rcv_process, TCP_ERROR_EVENT_FIFO_FULL, errors);
2802 tcp_inc_counter (rcv_process, TCP_ERROR_FIN_RCVD, n_fins);
2803 return from_frame->n_vectors;
2807 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2808 vlib_frame_t * from_frame)
2810 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2814 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2815 vlib_frame_t * from_frame)
2817 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2821 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2823 .function = tcp4_rcv_process,
2824 .name = "tcp4-rcv-process",
2825 /* Takes a vector of packets. */
2826 .vector_size = sizeof (u32),
2827 .n_errors = TCP_N_ERROR,
2828 .error_strings = tcp_error_strings,
2829 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2832 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2833 foreach_tcp_state_next
2836 .format_trace = format_tcp_rx_trace_short,
2840 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2843 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2845 .function = tcp6_rcv_process,
2846 .name = "tcp6-rcv-process",
2847 /* Takes a vector of packets. */
2848 .vector_size = sizeof (u32),
2849 .n_errors = TCP_N_ERROR,
2850 .error_strings = tcp_error_strings,
2851 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2854 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2855 foreach_tcp_state_next
2858 .format_trace = format_tcp_rx_trace_short,
2862 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2864 vlib_node_registration_t tcp4_listen_node;
2865 vlib_node_registration_t tcp6_listen_node;
2868 * LISTEN state processing as per RFC 793 p. 65
2871 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2872 vlib_frame_t * from_frame, int is_ip4)
2874 u32 n_left_from, next_index, *from, *to_next, n_syns = 0;
2875 u32 my_thread_index = vm->thread_index;
2877 from = vlib_frame_vector_args (from_frame);
2878 n_left_from = from_frame->n_vectors;
2880 next_index = node->cached_next_index;
2882 while (n_left_from > 0)
2886 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2888 while (n_left_from > 0 && n_left_to_next > 0)
2893 tcp_header_t *th0 = 0;
2894 tcp_connection_t *lc0;
2897 tcp_connection_t *child0;
2898 u32 error0 = TCP_ERROR_NONE, next0 = tcp_next_drop (is_ip4);
2905 n_left_to_next -= 1;
2907 b0 = vlib_get_buffer (vm, bi0);
2908 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2912 ip40 = vlib_buffer_get_current (b0);
2913 th0 = ip4_next_header (ip40);
2917 ip60 = vlib_buffer_get_current (b0);
2918 th0 = ip6_next_header (ip60);
2921 /* Create child session. For syn-flood protection use filter */
2923 /* 1. first check for an RST: handled in dispatch */
2924 /* if (tcp_rst (th0))
2927 /* 2. second check for an ACK: handled in dispatch */
2928 /* if (tcp_ack (th0))
2930 tcp_send_reset (b0, is_ip4);
2934 /* 3. check for a SYN (did that already) */
2936 /* Make sure connection wasn't just created */
2937 child0 = tcp_lookup_connection (lc0->c_fib_index, b0,
2938 my_thread_index, is_ip4);
2939 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
2941 error0 = TCP_ERROR_CREATE_EXISTS;
2945 /* Create child session and send SYN-ACK */
2946 child0 = tcp_connection_new (my_thread_index);
2947 child0->c_lcl_port = th0->dst_port;
2948 child0->c_rmt_port = th0->src_port;
2949 child0->c_is_ip4 = is_ip4;
2950 child0->state = TCP_STATE_SYN_RCVD;
2951 child0->c_fib_index = lc0->c_fib_index;
2955 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
2956 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
2960 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
2961 sizeof (ip6_address_t));
2962 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
2963 sizeof (ip6_address_t));
2966 if (tcp_options_parse (th0, &child0->rcv_opts))
2968 clib_warning ("options parse fail");
2972 child0->irs = vnet_buffer (b0)->tcp.seq_number;
2973 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
2974 child0->rcv_las = child0->rcv_nxt;
2975 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2977 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
2978 * segments are used to initialize PAWS. */
2979 if (tcp_opts_tstamp (&child0->rcv_opts))
2981 child0->tsval_recent = child0->rcv_opts.tsval;
2982 child0->tsval_recent_age = tcp_time_now ();
2985 if (tcp_opts_wscale (&child0->rcv_opts))
2986 child0->snd_wscale = child0->rcv_opts.wscale;
2988 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
2989 << child0->snd_wscale;
2990 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2991 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2993 tcp_connection_init_vars (child0);
2994 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
2996 if (stream_session_accept (&child0->connection, lc0->c_s_index,
2999 clib_warning ("session accept fail");
3000 tcp_connection_cleanup (child0);
3001 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3005 /* Reuse buffer to make syn-ack and send */
3006 tcp_make_synack (child0, b0);
3007 next0 = tcp_next_output (is_ip4);
3008 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
3011 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3013 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3014 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3015 clib_memcpy (&t0->tcp_connection, lc0,
3016 sizeof (t0->tcp_connection));
3019 n_syns += (error0 == TCP_ERROR_NONE);
3020 b0->error = node->errors[error0];
3022 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
3023 n_left_to_next, bi0, next0);
3026 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
3029 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3030 return from_frame->n_vectors;
3034 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3035 vlib_frame_t * from_frame)
3037 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3041 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3042 vlib_frame_t * from_frame)
3044 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3048 VLIB_REGISTER_NODE (tcp4_listen_node) =
3050 .function = tcp4_listen,
3051 .name = "tcp4-listen",
3052 /* Takes a vector of packets. */
3053 .vector_size = sizeof (u32),
3054 .n_errors = TCP_N_ERROR,
3055 .error_strings = tcp_error_strings,
3056 .n_next_nodes = TCP_LISTEN_N_NEXT,
3059 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3060 foreach_tcp_state_next
3063 .format_trace = format_tcp_rx_trace_short,
3067 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
3070 VLIB_REGISTER_NODE (tcp6_listen_node) =
3072 .function = tcp6_listen,
3073 .name = "tcp6-listen",
3074 /* Takes a vector of packets. */
3075 .vector_size = sizeof (u32),
3076 .n_errors = TCP_N_ERROR,
3077 .error_strings = tcp_error_strings,
3078 .n_next_nodes = TCP_LISTEN_N_NEXT,
3081 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3082 foreach_tcp_state_next
3085 .format_trace = format_tcp_rx_trace_short,
3089 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
3091 vlib_node_registration_t tcp4_input_node;
3092 vlib_node_registration_t tcp6_input_node;
3094 typedef enum _tcp_input_next
3096 TCP_INPUT_NEXT_DROP,
3097 TCP_INPUT_NEXT_LISTEN,
3098 TCP_INPUT_NEXT_RCV_PROCESS,
3099 TCP_INPUT_NEXT_SYN_SENT,
3100 TCP_INPUT_NEXT_ESTABLISHED,
3101 TCP_INPUT_NEXT_RESET,
3102 TCP_INPUT_NEXT_PUNT,
3106 #define foreach_tcp4_input_next \
3107 _ (DROP, "ip4-drop") \
3108 _ (LISTEN, "tcp4-listen") \
3109 _ (RCV_PROCESS, "tcp4-rcv-process") \
3110 _ (SYN_SENT, "tcp4-syn-sent") \
3111 _ (ESTABLISHED, "tcp4-established") \
3112 _ (RESET, "tcp4-reset") \
3113 _ (PUNT, "ip4-punt")
3115 #define foreach_tcp6_input_next \
3116 _ (DROP, "ip6-drop") \
3117 _ (LISTEN, "tcp6-listen") \
3118 _ (RCV_PROCESS, "tcp6-rcv-process") \
3119 _ (SYN_SENT, "tcp6-syn-sent") \
3120 _ (ESTABLISHED, "tcp6-established") \
3121 _ (RESET, "tcp6-reset") \
3122 _ (PUNT, "ip6-punt")
3124 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3127 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3128 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3130 tcp_connection_t *tc;
3135 for (i = 0; i < n_bufs; i++)
3137 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3139 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3140 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3142 tcp = vlib_buffer_get_current (bs[i]);
3143 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3149 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3151 if (*error == TCP_ERROR_FILTERED)
3153 *next = TCP_INPUT_NEXT_DROP;
3155 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3157 *next = TCP_INPUT_NEXT_PUNT;
3158 *error = TCP_ERROR_PUNT;
3162 *next = TCP_INPUT_NEXT_RESET;
3163 *error = TCP_ERROR_NO_LISTENER;
3167 static inline tcp_connection_t *
3168 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3171 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3172 int n_advance_bytes, n_data_bytes;
3173 transport_connection_t *tc;
3179 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3180 tcp = ip4_next_header (ip4);
3181 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3182 n_advance_bytes = (ip4_header_bytes (ip4) + tcp_header_bytes (tcp));
3183 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3185 /* Length check. Checksum computed by ipx_local no need to compute again */
3186 if (PREDICT_FALSE (n_advance_bytes < 0))
3188 *error = TCP_ERROR_LENGTH;
3192 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3193 &ip4->src_address, tcp->dst_port,
3194 tcp->src_port, TRANSPORT_PROTO_TCP,
3195 thread_index, &is_filtered);
3199 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3200 tcp = ip6_next_header (ip6);
3201 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3202 n_advance_bytes = tcp_header_bytes (tcp);
3203 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3205 n_advance_bytes += sizeof (ip6[0]);
3207 if (PREDICT_FALSE (n_advance_bytes < 0))
3209 *error = TCP_ERROR_LENGTH;
3213 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3214 &ip6->src_address, tcp->dst_port,
3215 tcp->src_port, TRANSPORT_PROTO_TCP,
3216 thread_index, &is_filtered);
3219 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3220 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3221 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3222 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3223 vnet_buffer (b)->tcp.flags = 0;
3225 *error = is_filtered ? TCP_ERROR_FILTERED : *error;
3227 return tcp_get_connection_from_transport (tc);
3231 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3232 vlib_buffer_t * b, u16 * next, u32 * error)
3237 tcp = tcp_buffer_hdr (b);
3238 flags = tcp->flags & filter_flags;
3239 *next = tm->dispatch_table[tc->state][flags].next;
3240 *error = tm->dispatch_table[tc->state][flags].error;
3242 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3243 || *next == TCP_INPUT_NEXT_RESET))
3245 /* Overload tcp flags to store state */
3246 tcp_state_t state = tc->state;
3247 vnet_buffer (b)->tcp.flags = tc->state;
3249 if (*error == TCP_ERROR_DISPATCH)
3250 clib_warning ("disp error state %U flags %U", format_tcp_state,
3251 state, format_tcp_flags, (int) flags);
3256 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3257 vlib_frame_t * frame, int is_ip4)
3259 u32 n_left_from, *from, thread_index = vm->thread_index;
3260 tcp_main_t *tm = vnet_get_tcp_main ();
3261 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3262 u16 nexts[VLIB_FRAME_SIZE], *next;
3264 tcp_set_time_now (thread_index);
3266 from = vlib_frame_vector_args (frame);
3267 n_left_from = frame->n_vectors;
3268 vlib_get_buffers (vm, from, bufs, n_left_from);
3273 while (n_left_from >= 4)
3275 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3276 tcp_connection_t *tc0, *tc1;
3279 vlib_prefetch_buffer_header (b[2], STORE);
3280 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3282 vlib_prefetch_buffer_header (b[3], STORE);
3283 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3286 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3288 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3289 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4);
3291 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3293 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3294 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3296 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3297 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3299 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3300 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3304 if (PREDICT_TRUE (tc0 != 0))
3306 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3307 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3308 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3311 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3313 if (PREDICT_TRUE (tc1 != 0))
3315 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3316 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3317 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3320 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3327 while (n_left_from > 0)
3329 tcp_connection_t *tc0;
3330 u32 error0 = TCP_ERROR_NO_LISTENER;
3332 if (n_left_from > 1)
3334 vlib_prefetch_buffer_header (b[1], STORE);
3335 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3338 next[0] = TCP_INPUT_NEXT_DROP;
3339 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3340 if (PREDICT_TRUE (tc0 != 0))
3342 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3343 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3344 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3347 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3354 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3355 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3357 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3358 return frame->n_vectors;
3362 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3363 vlib_frame_t * from_frame)
3365 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3369 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3370 vlib_frame_t * from_frame)
3372 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3376 VLIB_REGISTER_NODE (tcp4_input_node) =
3378 .function = tcp4_input,
3379 .name = "tcp4-input",
3380 /* Takes a vector of packets. */
3381 .vector_size = sizeof (u32),
3382 .n_errors = TCP_N_ERROR,
3383 .error_strings = tcp_error_strings,
3384 .n_next_nodes = TCP_INPUT_N_NEXT,
3387 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3388 foreach_tcp4_input_next
3391 .format_buffer = format_tcp_header,
3392 .format_trace = format_tcp_rx_trace,
3396 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3399 VLIB_REGISTER_NODE (tcp6_input_node) =
3401 .function = tcp6_input,
3402 .name = "tcp6-input",
3403 /* Takes a vector of packets. */
3404 .vector_size = sizeof (u32),
3405 .n_errors = TCP_N_ERROR,
3406 .error_strings = tcp_error_strings,
3407 .n_next_nodes = TCP_INPUT_N_NEXT,
3410 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3411 foreach_tcp6_input_next
3414 .format_buffer = format_tcp_header,
3415 .format_trace = format_tcp_rx_trace,
3419 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3422 tcp_dispatch_table_init (tcp_main_t * tm)
3425 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3426 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3428 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3429 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3432 #define _(t,f,n,e) \
3434 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3435 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3438 /* SYNs for new connections -> tcp-listen. */
3439 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3440 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3441 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_RST_RCVD);
3442 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3444 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3445 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3446 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3447 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3449 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3450 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3452 /* SYN-ACK for a SYN */
3453 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3455 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3456 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3457 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3459 /* ACK for for established connection -> tcp-established. */
3460 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3461 /* FIN for for established connection -> tcp-established. */
3462 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3463 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3465 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3466 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3468 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3469 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3471 /* ACK or FIN-ACK to our FIN */
3472 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3473 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3475 /* FIN in reply to our FIN from the other side */
3476 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3477 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3478 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3479 /* FIN confirming that the peer (app) has closed */
3480 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3481 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3482 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3484 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3485 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3487 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3488 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3489 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3491 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3492 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3493 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3495 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3496 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3497 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3498 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3499 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3500 TCP_ERROR_CONNECTION_CLOSED);
3504 static clib_error_t *
3505 tcp_input_init (vlib_main_t * vm)
3507 clib_error_t *error = 0;
3508 tcp_main_t *tm = vnet_get_tcp_main ();
3510 if ((error = vlib_call_init_function (vm, tcp_init)))
3513 /* Initialize dispatch table. */
3514 tcp_dispatch_table_init (tm);
3519 VLIB_INIT_FUNCTION (tcp_input_init);
3522 * fd.io coding-style-patch-verification: ON
3525 * eval: (c-set-style "gnu")