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);
140 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
144 /* Get options length */
145 if (kind == TCP_OPTION_EOL)
147 else if (kind == TCP_OPTION_NOOP)
159 /* weird option length */
160 if (opt_len < 2 || opt_len > opts_len)
168 if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
170 to->flags |= TCP_OPTS_FLAG_MSS;
171 to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
174 case TCP_OPTION_WINDOW_SCALE:
175 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
177 to->flags |= TCP_OPTS_FLAG_WSCALE;
178 to->wscale = data[2];
179 if (to->wscale > TCP_MAX_WND_SCALE)
181 clib_warning ("Illegal window scaling value: %d",
183 to->wscale = TCP_MAX_WND_SCALE;
187 case TCP_OPTION_TIMESTAMP:
188 if (opt_len == TCP_OPTION_LEN_TIMESTAMP)
190 to->flags |= TCP_OPTS_FLAG_TSTAMP;
191 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
192 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
195 case TCP_OPTION_SACK_PERMITTED:
196 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
197 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
199 case TCP_OPTION_SACK_BLOCK:
200 /* If SACK permitted was not advertised or a SYN, break */
201 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
204 /* If too short or not correctly formatted, break */
205 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
208 to->flags |= TCP_OPTS_FLAG_SACK;
209 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
210 vec_reset_length (to->sacks);
211 for (j = 0; j < to->n_sack_blocks; j++)
213 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 8 * j));
214 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 8 * j));
215 vec_add1 (to->sacks, b);
219 /* Nothing to see here */
227 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
228 * timestamp to echo and it's less than tsval_recent, drop segment
229 * but still send an ACK in order to retain TCP's mechanism for detecting
230 * and recovering from half-open connections
232 * Or at least that's what the theory says. It seems that this might not work
233 * very well with packet reordering and fast retransmit. XXX
236 tcp_segment_check_paws (tcp_connection_t * tc)
238 return tcp_opts_tstamp (&tc->rcv_opts) && tc->tsval_recent
239 && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent);
243 * Update tsval recent
246 tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
249 * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
250 * of an incoming segment:
251 * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
252 * then the TSval from the segment is copied to TS.Recent;
253 * otherwise, the TSval is ignored.
255 if (tcp_opts_tstamp (&tc->rcv_opts) && seq_leq (seq, tc->rcv_las)
256 && seq_leq (tc->rcv_las, seq_end))
258 ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval));
259 tc->tsval_recent = tc->rcv_opts.tsval;
260 tc->tsval_recent_age = tcp_time_now ();
265 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
267 * It first verifies if segment has a wrapped sequence number (PAWS) and then
268 * does the processing associated to the first four steps (ignoring security
269 * and precedence): sequence number, rst bit and syn bit checks.
271 * @return 0 if segments passes validation.
274 tcp_segment_validate (vlib_main_t * vm, tcp_connection_t * tc0,
275 vlib_buffer_t * b0, tcp_header_t * th0,
276 u32 * next0, u32 * error0)
278 /* We could get a burst of RSTs interleaved with acks */
279 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
281 tcp_send_reset (tc0);
282 *error0 = TCP_ERROR_CONNECTION_CLOSED;
286 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
288 *error0 = TCP_ERROR_SEGMENT_INVALID;
292 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts)))
294 clib_warning ("options parse error");
295 *error0 = TCP_ERROR_OPTIONS;
299 if (PREDICT_FALSE (tcp_segment_check_paws (tc0)))
301 *error0 = TCP_ERROR_PAWS;
303 clib_warning ("paws failed\n%U", format_tcp_connection, tc0, 2);
304 TCP_EVT_DBG (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
305 vnet_buffer (b0)->tcp.seq_end);
307 /* If it just so happens that a segment updates tsval_recent for a
308 * segment over 24 days old, invalidate tsval_recent. */
309 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
312 /* Age isn't reset until we get a valid tsval (bsd inspired) */
313 tc0->tsval_recent = 0;
314 clib_warning ("paws failed - really old segment. REALLY?");
318 /* Drop after ack if not rst */
321 tcp_make_ack (tc0, b0);
322 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
329 /* 1st: check sequence number */
330 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
331 vnet_buffer (b0)->tcp.seq_end))
333 *error0 = TCP_ERROR_RCV_WND;
334 /* If our window is 0 and the packet is in sequence, let it pass
335 * through for ack processing. It should be dropped later. */
336 if (!(tc0->rcv_wnd == 0
337 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number))
339 /* If not RST, send dup ack */
342 tcp_make_ack (tc0, b0);
343 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
350 /* 2nd: check the RST bit */
351 if (PREDICT_FALSE (tcp_rst (th0)))
353 tcp_connection_reset (tc0);
354 *error0 = TCP_ERROR_RST_RCVD;
358 /* 3rd: check security and precedence (skip) */
360 /* 4th: check the SYN bit */
361 if (PREDICT_FALSE (tcp_syn (th0)))
363 /* TODO implement RFC 5961 */
364 if (tc0->state == TCP_STATE_SYN_RCVD)
366 tcp_make_synack (tc0, b0);
367 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0, 0);
371 tcp_make_ack (tc0, b0);
372 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, tc0);
377 /* If segment in window, save timestamp */
378 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
379 vnet_buffer (b0)->tcp.seq_end);
383 *next0 = tcp_next_drop (tc0->c_is_ip4);
386 *next0 = tcp_next_output (tc0->c_is_ip4);
391 tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0)
393 /* SND.UNA =< SEG.ACK =< SND.NXT */
394 return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number)
395 && seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt));
399 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
401 * Note that although the original article, srtt and rttvar are scaled
402 * to minimize round-off errors, here we don't. Instead, we rely on
403 * better precision time measurements.
405 * TODO support us rtt resolution
408 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
414 err = mrtt - tc->srtt;
416 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
417 * The increase should be bound */
418 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
419 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
420 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
424 /* First measurement. */
426 tc->rttvar = mrtt >> 1;
431 tcp_update_rto (tcp_connection_t * tc)
433 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
434 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
438 * Update RTT estimate and RTO timer
440 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
441 * timing. Middle boxes are known to fiddle with TCP options so we
442 * should give higher priority to ACK timing.
444 * This should be called only if previously sent bytes have been acked.
446 * return 1 if valid rtt 0 otherwise
449 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
453 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
454 * RTT because they're ambiguous. */
455 if (tcp_in_cong_recovery (tc) || tc->sack_sb.sacked_bytes)
458 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
460 mrtt = tcp_time_now () - tc->rtt_ts;
462 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
463 * snd_una, i.e., the left side of the send window:
464 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
465 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
467 mrtt = tcp_time_now () - tc->rcv_opts.tsecr;
470 /* Ignore dubious measurements */
471 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
474 tcp_estimate_rtt (tc, mrtt);
478 /* Allow measuring of a new RTT */
481 /* If we got here something must've been ACKed so make sure boff is 0,
482 * even if mrrt is not valid since we update the rto lower */
490 * Dequeue bytes that have been acked and while at it update RTT estimates.
493 tcp_dequeue_acked (tcp_connection_t * tc, u32 ack)
495 /* Dequeue the newly ACKed add SACKed bytes */
496 stream_session_dequeue_drop (&tc->connection,
497 tc->bytes_acked + tc->sack_sb.snd_una_adv);
499 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
501 /* Update rtt and rto */
502 tcp_update_rtt (tc, ack);
504 /* If everything has been acked, stop retransmit timer
505 * otherwise update. */
506 tcp_retransmit_timer_update (tc);
510 * Check if duplicate ack as per RFC5681 Sec. 2
513 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
516 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
517 && seq_gt (tc->snd_una_max, tc->snd_una)
518 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
519 && (prev_snd_wnd == tc->snd_wnd));
523 * Checks if ack is a congestion control event.
526 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
527 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
529 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
530 * defined to be 'duplicate' */
531 *is_dack = tc->sack_sb.last_sacked_bytes
532 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
534 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
538 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
540 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
541 return hole - sb->holes;
545 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
547 return hole->end - hole->start;
550 sack_scoreboard_hole_t *
551 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
553 if (index != TCP_INVALID_SACK_HOLE_INDEX)
554 return pool_elt_at_index (sb->holes, index);
558 sack_scoreboard_hole_t *
559 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
561 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
562 return pool_elt_at_index (sb->holes, hole->next);
566 sack_scoreboard_hole_t *
567 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
569 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
570 return pool_elt_at_index (sb->holes, hole->prev);
574 sack_scoreboard_hole_t *
575 scoreboard_first_hole (sack_scoreboard_t * sb)
577 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
578 return pool_elt_at_index (sb->holes, sb->head);
582 sack_scoreboard_hole_t *
583 scoreboard_last_hole (sack_scoreboard_t * sb)
585 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
586 return pool_elt_at_index (sb->holes, sb->tail);
591 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
593 sack_scoreboard_hole_t *next, *prev;
595 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
597 next = pool_elt_at_index (sb->holes, hole->next);
598 next->prev = hole->prev;
602 sb->tail = hole->prev;
605 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
607 prev = pool_elt_at_index (sb->holes, hole->prev);
608 prev->next = hole->next;
612 sb->head = hole->next;
615 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
616 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
618 /* Poison the entry */
620 memset (hole, 0xfe, sizeof (*hole));
622 pool_put (sb->holes, hole);
625 static sack_scoreboard_hole_t *
626 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
629 sack_scoreboard_hole_t *hole, *next, *prev;
632 pool_get (sb->holes, hole);
633 memset (hole, 0, sizeof (*hole));
637 hole_index = scoreboard_hole_index (sb, hole);
639 prev = scoreboard_get_hole (sb, prev_index);
642 hole->prev = prev_index;
643 hole->next = prev->next;
645 if ((next = scoreboard_next_hole (sb, hole)))
646 next->prev = hole_index;
648 sb->tail = hole_index;
650 prev->next = hole_index;
654 sb->head = hole_index;
655 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
656 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
663 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
665 sack_scoreboard_hole_t *hole, *prev;
666 u32 bytes = 0, blks = 0;
669 sb->sacked_bytes = 0;
670 hole = scoreboard_last_hole (sb);
674 if (seq_gt (sb->high_sacked, hole->end))
676 bytes = sb->high_sacked - hole->end;
680 while ((prev = scoreboard_prev_hole (sb, hole))
681 && (bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
682 && blks < TCP_DUPACK_THRESHOLD))
684 bytes += hole->start - prev->end;
691 sb->lost_bytes += scoreboard_hole_bytes (hole);
694 hole = scoreboard_prev_hole (sb, hole);
696 bytes += prev->start - hole->end;
698 sb->sacked_bytes = bytes;
702 * Figure out the next hole to retransmit
704 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
706 sack_scoreboard_hole_t *
707 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
708 sack_scoreboard_hole_t * start,
710 u8 * can_rescue, u8 * snd_limited)
712 sack_scoreboard_hole_t *hole = 0;
714 hole = start ? start : scoreboard_first_hole (sb);
715 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
716 hole = scoreboard_next_hole (sb, hole);
718 /* Nothing, return */
721 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
725 /* Rule (1): if higher than rxt, less than high_sacked and lost */
726 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
728 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
732 /* Rule (2): output takes care of transmitting new data */
733 if (!have_sent_1_smss)
736 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
738 /* Rule (3): if hole not lost */
739 else if (seq_lt (hole->start, sb->high_sacked))
742 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
744 /* Rule (4): if hole beyond high_sacked */
747 ASSERT (seq_geq (hole->start, sb->high_sacked));
750 /* HighRxt MUST NOT be updated */
755 if (hole && seq_lt (sb->high_rxt, hole->start))
756 sb->high_rxt = hole->start;
762 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 seq)
764 sack_scoreboard_hole_t *hole;
765 hole = scoreboard_first_hole (sb);
768 seq = seq_gt (seq, hole->start) ? seq : hole->start;
769 sb->cur_rxt_hole = sb->head;
775 scoreboard_init (sack_scoreboard_t * sb)
777 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
778 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
779 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
783 scoreboard_clear (sack_scoreboard_t * sb)
785 sack_scoreboard_hole_t *hole;
786 while ((hole = scoreboard_first_hole (sb)))
788 scoreboard_remove_hole (sb, hole);
790 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
791 ASSERT (pool_elts (sb->holes) == 0);
792 sb->sacked_bytes = 0;
793 sb->last_sacked_bytes = 0;
794 sb->last_bytes_delivered = 0;
799 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
803 * Test that scoreboard is sane after recovery
805 * Returns 1 if scoreboard is empty or if first hole beyond
809 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
811 sack_scoreboard_hole_t *hole;
812 hole = scoreboard_first_hole (&tc->sack_sb);
813 return (!hole || seq_geq (hole->start, tc->snd_una));
817 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
819 sack_scoreboard_t *sb = &tc->sack_sb;
820 sack_block_t *blk, tmp;
821 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
822 u32 blk_index = 0, old_sacked_bytes, hole_index;
825 sb->last_sacked_bytes = 0;
826 sb->last_bytes_delivered = 0;
829 if (!tcp_opts_sack (&tc->rcv_opts)
830 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
833 old_sacked_bytes = sb->sacked_bytes;
835 /* Remove invalid blocks */
836 blk = tc->rcv_opts.sacks;
837 while (blk < vec_end (tc->rcv_opts.sacks))
839 if (seq_lt (blk->start, blk->end)
840 && seq_gt (blk->start, tc->snd_una)
841 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_una_max))
846 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
849 /* Add block for cumulative ack */
850 if (seq_gt (ack, tc->snd_una))
852 tmp.start = tc->snd_una;
854 vec_add1 (tc->rcv_opts.sacks, tmp);
857 if (vec_len (tc->rcv_opts.sacks) == 0)
860 tcp_scoreboard_trace_add (tc, ack);
862 /* Make sure blocks are ordered */
863 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
864 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
865 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
867 tmp = tc->rcv_opts.sacks[i];
868 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
869 tc->rcv_opts.sacks[j] = tmp;
872 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
874 /* If no holes, insert the first that covers all outstanding bytes */
875 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
876 tc->snd_una, tc->snd_una_max);
877 sb->tail = scoreboard_hole_index (sb, last_hole);
878 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
879 sb->high_sacked = tmp.end;
883 /* If we have holes but snd_una_max is beyond the last hole, update
885 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
886 last_hole = scoreboard_last_hole (sb);
887 if (seq_gt (tc->snd_una_max, last_hole->end))
889 if (seq_geq (last_hole->start, sb->high_sacked))
891 last_hole->end = tc->snd_una_max;
893 /* New hole after high sacked block */
894 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
896 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
900 /* Keep track of max byte sacked for when the last hole
902 if (seq_gt (tmp.end, sb->high_sacked))
903 sb->high_sacked = tmp.end;
906 /* Walk the holes with the SACK blocks */
907 hole = pool_elt_at_index (sb->holes, sb->head);
908 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
910 blk = &tc->rcv_opts.sacks[blk_index];
911 if (seq_leq (blk->start, hole->start))
913 /* Block covers hole. Remove hole */
914 if (seq_geq (blk->end, hole->end))
916 next_hole = scoreboard_next_hole (sb, hole);
918 /* Byte accounting: snd_una needs to be advanced */
923 if (seq_lt (ack, next_hole->start))
924 sb->snd_una_adv = next_hole->start - ack;
925 sb->last_bytes_delivered +=
926 next_hole->start - hole->end;
930 ASSERT (seq_geq (sb->high_sacked, ack));
931 sb->snd_una_adv = sb->high_sacked - ack;
932 sb->last_bytes_delivered += sb->high_sacked - hole->end;
936 scoreboard_remove_hole (sb, hole);
939 /* Partial 'head' overlap */
942 if (seq_gt (blk->end, hole->start))
944 hole->start = blk->end;
951 /* Hole must be split */
952 if (seq_lt (blk->end, hole->end))
954 hole_index = scoreboard_hole_index (sb, hole);
955 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
958 /* Pool might've moved */
959 hole = scoreboard_get_hole (sb, hole_index);
960 hole->end = blk->start;
962 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
964 else if (seq_lt (blk->start, hole->end))
966 hole->end = blk->start;
968 hole = scoreboard_next_hole (sb, hole);
972 scoreboard_update_bytes (tc, sb);
973 sb->last_sacked_bytes = sb->sacked_bytes
974 - (old_sacked_bytes - sb->last_bytes_delivered);
975 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
976 ASSERT (sb->sacked_bytes == 0
977 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
978 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
979 - seq_max (tc->snd_una, ack));
980 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
981 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
982 TCP_EVT_DBG (TCP_EVT_CC_SCOREBOARD, tc);
986 * Try to update snd_wnd based on feedback received from peer.
988 * If successful, and new window is 'effectively' 0, activate persist
992 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
994 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
995 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
996 if (seq_lt (tc->snd_wl1, seq)
997 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
999 tc->snd_wnd = snd_wnd;
1002 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
1004 if (tc->snd_wnd < tc->snd_mss)
1006 /* Set persist timer if not set and we just got 0 wnd */
1007 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1008 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1009 tcp_persist_timer_set (tc);
1013 tcp_persist_timer_reset (tc);
1014 if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
1017 tcp_update_rto (tc);
1024 * Init loss recovery/fast recovery.
1026 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1027 * updated in @ref tcp_cc_handle_event after fast retransmit
1030 tcp_cc_init_congestion (tcp_connection_t * tc)
1032 tcp_fastrecovery_on (tc);
1033 tc->snd_congestion = tc->snd_una_max;
1034 tc->cwnd_acc_bytes = 0;
1035 tc->cc_algo->congestion (tc);
1036 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
1040 tcp_cc_recovery_exit (tcp_connection_t * tc)
1043 tcp_update_rto (tc);
1045 tc->snd_nxt = tc->snd_una_max;
1046 tcp_recovery_off (tc);
1047 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1051 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
1053 tc->cc_algo->recovered (tc);
1054 tc->snd_rxt_bytes = 0;
1055 tc->rcv_dupacks = 0;
1056 tc->snd_nxt = tc->snd_una_max;
1057 tcp_fastrecovery_off (tc);
1058 tcp_fastrecovery_1_smss_off (tc);
1059 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1063 tcp_cc_congestion_undo (tcp_connection_t * tc)
1065 tc->cwnd = tc->prev_cwnd;
1066 tc->ssthresh = tc->prev_ssthresh;
1067 tc->snd_nxt = tc->snd_una_max;
1068 tc->rcv_dupacks = 0;
1069 if (tcp_in_recovery (tc))
1070 tcp_cc_recovery_exit (tc);
1071 ASSERT (tc->rto_boff == 0);
1072 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
1073 /* TODO extend for fastrecovery */
1077 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1079 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1081 && tcp_opts_tstamp (&tc->rcv_opts)
1082 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1086 tcp_cc_recover (tcp_connection_t * tc)
1088 ASSERT (tcp_in_cong_recovery (tc));
1089 if (tcp_cc_is_spurious_retransmit (tc))
1091 tcp_cc_congestion_undo (tc);
1095 if (tcp_in_recovery (tc))
1096 tcp_cc_recovery_exit (tc);
1097 else if (tcp_in_fastrecovery (tc))
1098 tcp_cc_fastrecovery_exit (tc);
1100 ASSERT (tc->rto_boff == 0);
1101 ASSERT (!tcp_in_cong_recovery (tc));
1102 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1107 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
1109 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1111 /* Congestion avoidance */
1112 tc->cc_algo->rcv_ack (tc);
1113 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1115 /* If a cumulative ack, make sure dupacks is 0 */
1116 tc->rcv_dupacks = 0;
1118 /* When dupacks hits the threshold we only enter fast retransmit if
1119 * cumulative ack covers more than snd_congestion. Should snd_una
1120 * wrap this test may fail under otherwise valid circumstances.
1121 * Therefore, proactively update snd_congestion when wrap detected. */
1123 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1124 && seq_gt (tc->snd_congestion, tc->snd_una)))
1125 tc->snd_congestion = tc->snd_una - 1;
1129 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1131 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1135 tcp_should_fastrecover (tcp_connection_t * tc)
1137 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1138 || tcp_should_fastrecover_sack (tc));
1142 * One function to rule them all ... and in the darkness bind them
1145 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1149 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1151 if (tc->bytes_acked)
1153 tcp_fast_retransmit (tc);
1157 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1158 * it account for the bytes that left the network.
1160 else if (is_dack && !tcp_in_recovery (tc))
1162 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1163 ASSERT (tc->snd_una != tc->snd_una_max
1164 || tc->sack_sb.last_sacked_bytes);
1168 /* Pure duplicate ack. If some data got acked, it's handled lower */
1169 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1171 ASSERT (tcp_in_fastrecovery (tc));
1172 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1175 else if (tcp_should_fastrecover (tc))
1177 ASSERT (!tcp_in_fastrecovery (tc));
1179 /* If of of the two conditions lower hold, reset dupacks because
1180 * we're probably after timeout (RFC6582 heuristics).
1181 * If Cumulative ack does not cover more than congestion threshold,
1183 * 1) The following doesn't hold: The congestion window is greater
1184 * than SMSS bytes and the difference between highest_ack
1185 * and prev_highest_ack is at most 4*SMSS bytes
1186 * 2) Echoed timestamp in the last non-dup ack does not equal the
1189 if (seq_leq (tc->snd_una, tc->snd_congestion)
1190 && ((!(tc->cwnd > tc->snd_mss
1191 && tc->bytes_acked <= 4 * tc->snd_mss))
1192 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1194 tc->rcv_dupacks = 0;
1198 tcp_cc_init_congestion (tc);
1199 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1201 /* The first segment MUST be retransmitted */
1202 tcp_retransmit_first_unacked (tc);
1204 /* Post retransmit update cwnd to ssthresh and account for the
1205 * three segments that have left the network and should've been
1206 * buffered at the receiver XXX */
1207 tc->cwnd = tc->ssthresh + tc->rcv_dupacks * tc->snd_mss;
1208 ASSERT (tc->cwnd >= tc->snd_mss);
1210 /* If cwnd allows, send more data */
1211 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1213 scoreboard_init_high_rxt (&tc->sack_sb,
1214 tc->snd_una + tc->snd_mss);
1215 tcp_fast_retransmit_sack (tc);
1219 tcp_fast_retransmit_no_sack (tc);
1223 else if (!tc->bytes_acked
1224 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1226 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1233 if (!tc->bytes_acked)
1237 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1240 * Legitimate ACK. 1) See if we can exit recovery
1242 /* XXX limit this only to first partial ack? */
1243 tcp_retransmit_timer_update (tc);
1245 if (seq_geq (tc->snd_una, tc->snd_congestion))
1247 /* If spurious return, we've already updated everything */
1248 if (tcp_cc_recover (tc))
1250 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1254 tc->snd_nxt = tc->snd_una_max;
1256 /* Treat as congestion avoidance ack */
1257 tc->cc_algo->rcv_ack (tc);
1258 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1263 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1266 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1267 * reset dupacks to 0. Also needed if in congestion recovery */
1268 tc->rcv_dupacks = 0;
1270 /* Post RTO timeout don't try anything fancy */
1271 if (tcp_in_recovery (tc))
1273 tc->cc_algo->rcv_ack (tc);
1274 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1278 /* Remove retransmitted bytes that have been delivered */
1279 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1280 >= tc->sack_sb.last_bytes_delivered
1281 || (tc->flags & TCP_CONN_FINSNT));
1283 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1285 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1286 * remove sacked bytes delivered */
1287 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1288 - tc->sack_sb.last_bytes_delivered;
1289 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1290 tc->snd_rxt_bytes -= rxt_delivered;
1294 /* Either all retransmitted holes have been acked, or we're
1295 * "in the blind" and retransmitting segment by segment */
1296 tc->snd_rxt_bytes = 0;
1299 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1302 * Since this was a partial ack, try to retransmit some more data
1304 tcp_fast_retransmit (tc);
1308 * Process incoming ACK
1311 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
1312 tcp_header_t * th, u32 * next, u32 * error)
1314 u32 prev_snd_wnd, prev_snd_una;
1317 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1319 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1320 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1322 /* When we entered recovery, we reset snd_nxt to snd_una. Seems peer
1323 * still has the data so accept the ack */
1324 if (tcp_in_recovery (tc)
1325 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_congestion)
1326 && seq_geq (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
1328 tc->snd_una_max = tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1332 /* If we have outstanding data and this is within the window, accept it,
1333 * probably retransmit has timed out. Otherwise ACK segment and then
1335 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1337 tcp_make_ack (tc, b);
1338 *next = tcp_next_output (tc->c_is_ip4);
1339 *error = TCP_ERROR_ACK_INVALID;
1340 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1341 vnet_buffer (b)->tcp.ack_number);
1345 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1346 vnet_buffer (b)->tcp.ack_number);
1348 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1349 *error = TCP_ERROR_ACK_FUTURE;
1352 /* If old ACK, probably it's an old dupack */
1353 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1355 *error = TCP_ERROR_ACK_OLD;
1356 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1357 vnet_buffer (b)->tcp.ack_number);
1358 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1359 tcp_cc_handle_event (tc, 1);
1360 /* Don't drop yet */
1365 * Looks okay, process feedback
1368 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1369 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1371 prev_snd_wnd = tc->snd_wnd;
1372 prev_snd_una = tc->snd_una;
1373 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1374 vnet_buffer (b)->tcp.ack_number,
1375 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1376 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1377 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1378 tcp_validate_txf_size (tc, tc->bytes_acked);
1380 if (tc->bytes_acked)
1381 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
1383 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1386 * Check if we have congestion event
1389 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1391 tcp_cc_handle_event (tc, is_dack);
1392 if (!tcp_in_cong_recovery (tc))
1394 *error = TCP_ERROR_ACK_DUP;
1395 return vnet_buffer (b)->tcp.data_len ? 0 : -1;
1399 * Update congestion control (slow start/congestion avoidance)
1401 tcp_cc_update (tc, b);
1402 *error = TCP_ERROR_ACK_OK;
1407 tcp_sack_vector_is_sane (sack_block_t * sacks)
1410 for (i = 1; i < vec_len (sacks); i++)
1412 if (sacks[i - 1].end == sacks[i].start)
1419 * Build SACK list as per RFC2018.
1421 * Makes sure the first block contains the segment that generated the current
1422 * ACK and the following ones are the ones most recently reported in SACK
1425 * @param tc TCP connection for which the SACK list is updated
1426 * @param start Start sequence number of the newest SACK block
1427 * @param end End sequence of the newest SACK block
1430 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1432 sack_block_t *new_list = 0, *block = 0;
1435 /* If the first segment is ooo add it to the list. Last write might've moved
1436 * rcv_nxt over the first segment. */
1437 if (seq_lt (tc->rcv_nxt, start))
1439 vec_add2 (new_list, block, 1);
1440 block->start = start;
1444 /* Find the blocks still worth keeping. */
1445 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1447 /* Discard if rcv_nxt advanced beyond current block */
1448 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1451 /* Merge or drop if segment overlapped by the new segment */
1452 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1453 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1455 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1456 new_list[0].start = tc->snd_sacks[i].start;
1457 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1458 new_list[0].end = tc->snd_sacks[i].end;
1462 /* Save to new SACK list if we have space. */
1463 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1465 vec_add1 (new_list, tc->snd_sacks[i]);
1469 clib_warning ("sack discarded");
1473 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1475 /* Replace old vector with new one */
1476 vec_free (tc->snd_sacks);
1477 tc->snd_sacks = new_list;
1479 /* Segments should not 'touch' */
1480 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1484 tcp_sack_list_bytes (tcp_connection_t * tc)
1487 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1488 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1492 /** Enqueue data for delivery to application */
1494 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1497 int written, error = TCP_ERROR_ENQUEUED;
1499 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1501 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1502 1 /* queue event */ , 1);
1504 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1506 /* Update rcv_nxt */
1507 if (PREDICT_TRUE (written == data_len))
1509 tc->rcv_nxt += written;
1511 /* If more data written than expected, account for out-of-order bytes. */
1512 else if (written > data_len)
1514 tc->rcv_nxt += written;
1516 /* Send ACK confirming the update */
1517 tc->flags |= TCP_CONN_SNDACK;
1518 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1520 else if (written > 0)
1522 /* We've written something but FIFO is probably full now */
1523 tc->rcv_nxt += written;
1525 /* Depending on how fast the app is, all remaining buffers in burst will
1526 * not be enqueued. Inform peer */
1527 tc->flags |= TCP_CONN_SNDACK;
1529 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1533 tc->flags |= TCP_CONN_SNDACK;
1534 return TCP_ERROR_FIFO_FULL;
1537 /* Update SACK list if need be */
1538 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1540 /* Remove SACK blocks that have been delivered */
1541 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1547 /** Enqueue out-of-order data */
1549 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1552 stream_session_t *s0;
1555 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1558 /* Enqueue out-of-order data with relative offset */
1559 rv = session_enqueue_stream_connection (&tc->connection, b,
1560 vnet_buffer (b)->tcp.seq_number -
1561 tc->rcv_nxt, 0 /* queue event */ ,
1564 /* Nothing written */
1567 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1568 return TCP_ERROR_FIFO_FULL;
1571 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1573 /* Update SACK list if in use */
1574 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1576 ooo_segment_t *newest;
1579 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1581 /* Get the newest segment from the fifo */
1582 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1585 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1586 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1587 start = tc->rcv_nxt + offset;
1588 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1589 tcp_update_sack_list (tc, start, end);
1590 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1591 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1595 return TCP_ERROR_ENQUEUED_OOO;
1599 * Check if ACK could be delayed. If ack can be delayed, it should return
1600 * true for a full frame. If we're always acking return 0.
1603 tcp_can_delack (tcp_connection_t * tc)
1605 /* Send ack if ... */
1607 /* just sent a rcv wnd 0 */
1608 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1609 /* constrained to send ack */
1610 || (tc->flags & TCP_CONN_SNDACK) != 0
1611 /* we're almost out of tx wnd */
1612 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1619 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1621 u32 discard, first = b->current_length;
1622 vlib_main_t *vm = vlib_get_main ();
1624 /* Handle multi-buffer segments */
1625 if (n_bytes_to_drop > b->current_length)
1627 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1631 discard = clib_min (n_bytes_to_drop, b->current_length);
1632 vlib_buffer_advance (b, discard);
1633 b = vlib_get_buffer (vm, b->next_buffer);
1634 n_bytes_to_drop -= discard;
1636 while (n_bytes_to_drop);
1637 if (n_bytes_to_drop > first)
1638 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1641 vlib_buffer_advance (b, n_bytes_to_drop);
1642 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1647 * Receive buffer for connection and handle acks
1649 * It handles both in order or out-of-order data.
1652 tcp_segment_rcv (tcp_connection_t * tc, vlib_buffer_t * b, u32 * next0)
1654 u32 error, n_bytes_to_drop, n_data_bytes;
1656 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1657 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1658 ASSERT (n_data_bytes);
1660 /* Handle out-of-order data */
1661 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1663 /* Old sequence numbers allowed through because they overlapped
1665 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1667 /* Completely in the past (possible retransmit). Ack
1668 * retransmissions since we may not have any data to send */
1669 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1671 tcp_make_ack (tc, b);
1672 error = TCP_ERROR_SEGMENT_OLD;
1673 *next0 = tcp_next_output (tc->c_is_ip4);
1677 /* Chop off the bytes in the past and see if what is left
1678 * can be enqueued in order */
1679 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1680 n_data_bytes -= n_bytes_to_drop;
1681 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1682 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1684 error = TCP_ERROR_SEGMENT_OLD;
1685 *next0 = tcp_next_drop (tc->c_is_ip4);
1691 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1692 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1693 *next0 = tcp_next_output (tc->c_is_ip4);
1694 tcp_make_ack (tc, b);
1695 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1696 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1702 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1703 * segments can be enqueued after fifo tail offset changes. */
1704 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1705 if (tcp_can_delack (tc))
1707 *next0 = tcp_next_drop (tc->c_is_ip4);
1708 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1709 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1713 *next0 = tcp_next_output (tc->c_is_ip4);
1714 tcp_make_ack (tc, b);
1722 tcp_header_t tcp_header;
1723 tcp_connection_t tcp_connection;
1727 format_tcp_rx_trace (u8 * s, va_list * args)
1729 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1730 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1731 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1732 u32 indent = format_get_indent (s);
1734 s = format (s, "%U\n%U%U",
1735 format_tcp_header, &t->tcp_header, 128,
1736 format_white_space, indent,
1737 format_tcp_connection, &t->tcp_connection, 1);
1743 format_tcp_rx_trace_short (u8 * s, va_list * args)
1745 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1746 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1747 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1749 s = format (s, "%d -> %d (%U)",
1750 clib_net_to_host_u16 (t->tcp_header.dst_port),
1751 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
1752 t->tcp_connection.state);
1758 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1759 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1763 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1767 th0 = tcp_buffer_hdr (b0);
1769 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1773 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
1774 vlib_frame_t * frame, u8 is_ip4)
1778 n_left = frame->n_vectors;
1779 from = vlib_frame_vector_args (frame);
1783 tcp_connection_t *tc0;
1790 b0 = vlib_get_buffer (vm, bi0);
1792 if (b0->flags & VLIB_BUFFER_IS_TRACED)
1794 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1795 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1797 th0 = tcp_buffer_hdr (b0);
1798 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1807 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
1808 u8 is_ip4, u32 evt, u32 val)
1811 vlib_node_increment_counter (vm, tcp4_node, evt, val);
1813 vlib_node_increment_counter (vm, tcp6_node, evt, val);
1816 #define tcp_maybe_inc_counter(node_id, err, count) \
1818 if (next0 != tcp_next_drop (is_ip4)) \
1819 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1820 tcp6_##node_id##_node.index, is_ip4, err, \
1823 #define tcp_inc_counter(node_id, err, count) \
1824 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1825 tcp6_##node_id##_node.index, is_ip4, \
1827 #define tcp_maybe_inc_err_counter(cnts, err) \
1829 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
1831 #define tcp_inc_err_counter(cnts, err, val) \
1835 #define tcp_store_err_counters(node_id, cnts) \
1838 for (i = 0; i < TCP_N_ERROR; i++) \
1840 tcp_inc_counter(node_id, i, cnts[i]); \
1845 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1846 vlib_frame_t * frame, int is_ip4)
1848 u32 thread_index = vm->thread_index, errors = 0;
1849 u32 n_left_from, next_index, *from, *to_next;
1850 u16 err_counters[TCP_N_ERROR] = { 0 };
1853 if (node->flags & VLIB_NODE_FLAG_TRACE)
1854 tcp_established_trace_frame (vm, node, frame, is_ip4);
1856 from = vlib_frame_vector_args (frame);
1857 n_left_from = frame->n_vectors;
1858 next_index = node->cached_next_index;
1860 while (n_left_from > 0)
1864 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1865 while (n_left_from > 0 && n_left_to_next > 0)
1869 tcp_header_t *th0 = 0;
1870 tcp_connection_t *tc0;
1871 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ACK_OK;
1873 if (n_left_from > 1)
1876 pb = vlib_get_buffer (vm, from[1]);
1877 vlib_prefetch_buffer_header (pb, LOAD);
1878 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
1886 n_left_to_next -= 1;
1888 b0 = vlib_get_buffer (vm, bi0);
1889 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1892 if (PREDICT_FALSE (tc0 == 0))
1894 error0 = TCP_ERROR_INVALID_CONNECTION;
1898 th0 = tcp_buffer_hdr (b0);
1899 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
1900 * dangling reference. */
1901 is_fin = tcp_is_fin (th0);
1903 /* SYNs, FINs and data consume sequence numbers */
1904 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1905 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
1907 /* TODO header prediction fast path */
1909 /* 1-4: check SEQ, RST, SYN */
1910 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0,
1913 tcp_maybe_inc_err_counter (err_counters, error0);
1914 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
1918 /* 5: check the ACK field */
1919 if (PREDICT_FALSE (tcp_rcv_ack (tc0, b0, th0, &next0, &error0)))
1921 tcp_maybe_inc_err_counter (err_counters, error0);
1925 /* 6: check the URG bit TODO */
1927 /* 7: process the segment text */
1928 if (vnet_buffer (b0)->tcp.data_len)
1930 error0 = tcp_segment_rcv (tc0, b0, &next0);
1931 tcp_maybe_inc_err_counter (err_counters, error0);
1934 /* 8: check the FIN bit */
1935 if (PREDICT_FALSE (is_fin))
1937 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1938 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1939 /* Account for the FIN if nothing else was received */
1940 if (vnet_buffer (b0)->tcp.data_len == 0)
1942 tcp_make_ack (tc0, b0);
1943 next0 = tcp_next_output (tc0->c_is_ip4);
1944 tc0->state = TCP_STATE_CLOSE_WAIT;
1945 stream_session_disconnect_notify (&tc0->connection);
1946 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1947 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1948 tcp_inc_err_counter (err_counters, TCP_ERROR_FIN_RCVD, 1);
1952 b0->error = node->errors[error0];
1953 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1954 n_left_to_next, bi0, next0);
1957 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1960 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
1962 err_counters[TCP_ERROR_EVENT_FIFO_FULL] = errors;
1963 tcp_store_err_counters (established, err_counters);
1964 tcp_flush_frame_to_output (vm, thread_index, is_ip4);
1966 return frame->n_vectors;
1970 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1971 vlib_frame_t * from_frame)
1973 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1977 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1978 vlib_frame_t * from_frame)
1980 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1984 VLIB_REGISTER_NODE (tcp4_established_node) =
1986 .function = tcp4_established,
1987 .name = "tcp4-established",
1988 /* Takes a vector of packets. */
1989 .vector_size = sizeof (u32),
1990 .n_errors = TCP_N_ERROR,
1991 .error_strings = tcp_error_strings,
1992 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1995 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1996 foreach_tcp_state_next
1999 .format_trace = format_tcp_rx_trace_short,
2003 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
2006 VLIB_REGISTER_NODE (tcp6_established_node) =
2008 .function = tcp6_established,
2009 .name = "tcp6-established",
2010 /* Takes a vector of packets. */
2011 .vector_size = sizeof (u32),
2012 .n_errors = TCP_N_ERROR,
2013 .error_strings = tcp_error_strings,
2014 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2017 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2018 foreach_tcp_state_next
2021 .format_trace = format_tcp_rx_trace_short,
2026 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
2028 vlib_node_registration_t tcp4_syn_sent_node;
2029 vlib_node_registration_t tcp6_syn_sent_node;
2032 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2034 transport_connection_t *tmp = 0;
2041 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2044 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2045 && (tc->state == TCP_STATE_LISTEN
2046 || tc->c_rmt_port == hdr->src_port));
2050 handle = session_lookup_half_open_handle (&tc->connection);
2051 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2052 tc->c_proto, tc->c_is_ip4);
2056 if (tmp->lcl_port == hdr->dst_port
2057 && tmp->rmt_port == hdr->src_port)
2059 TCP_DBG ("half-open is valid!");
2067 * Lookup transport connection
2069 static tcp_connection_t *
2070 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2074 transport_connection_t *tconn;
2075 tcp_connection_t *tc;
2080 ip4 = vlib_buffer_get_current (b);
2081 tcp = ip4_next_header (ip4);
2082 tconn = session_lookup_connection_wt4 (fib_index,
2087 TRANSPORT_PROTO_TCP,
2088 thread_index, &is_filtered);
2089 tc = tcp_get_connection_from_transport (tconn);
2090 ASSERT (tcp_lookup_is_valid (tc, tcp));
2095 ip6 = vlib_buffer_get_current (b);
2096 tcp = ip6_next_header (ip6);
2097 tconn = session_lookup_connection_wt6 (fib_index,
2102 TRANSPORT_PROTO_TCP,
2103 thread_index, &is_filtered);
2104 tc = tcp_get_connection_from_transport (tconn);
2105 ASSERT (tcp_lookup_is_valid (tc, tcp));
2111 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2112 vlib_frame_t * from_frame, int is_ip4)
2114 tcp_main_t *tm = vnet_get_tcp_main ();
2115 u32 n_left_from, next_index, *from, *to_next;
2116 u32 my_thread_index = vm->thread_index, errors = 0;
2118 from = vlib_frame_vector_args (from_frame);
2119 n_left_from = from_frame->n_vectors;
2121 next_index = node->cached_next_index;
2123 while (n_left_from > 0)
2127 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2129 while (n_left_from > 0 && n_left_to_next > 0)
2131 u32 bi0, ack0, seq0;
2134 tcp_header_t *tcp0 = 0;
2135 tcp_connection_t *tc0;
2136 tcp_connection_t *new_tc0;
2137 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ENQUEUED;
2144 n_left_to_next -= 1;
2146 b0 = vlib_get_buffer (vm, bi0);
2148 tcp_half_open_connection_get (vnet_buffer (b0)->
2149 tcp.connection_index);
2150 if (PREDICT_FALSE (tc0 == 0))
2152 error0 = TCP_ERROR_INVALID_CONNECTION;
2156 /* Half-open completed recently but the connection was't removed
2157 * yet by the owning thread */
2158 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2160 /* Make sure the connection actually exists */
2161 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2162 my_thread_index, is_ip4));
2166 ack0 = vnet_buffer (b0)->tcp.ack_number;
2167 seq0 = vnet_buffer (b0)->tcp.seq_number;
2168 tcp0 = tcp_buffer_hdr (b0);
2170 /* Crude check to see if the connection handle does not match
2171 * the packet. Probably connection just switched to established */
2172 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2173 || tcp0->src_port != tc0->c_rmt_port))
2177 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
2180 /* SYNs, FINs and data consume sequence numbers */
2181 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
2182 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
2185 * 1. check the ACK bit
2189 * If the ACK bit is set
2190 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2191 * the RST bit is set, if so drop the segment and return)
2192 * <SEQ=SEG.ACK><CTL=RST>
2193 * and discard the segment. Return.
2194 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2198 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2200 clib_warning ("ack not in rcv wnd");
2201 if (!tcp_rst (tcp0))
2202 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2206 /* Make sure ACK is valid */
2207 if (seq_gt (tc0->snd_una, ack0))
2209 clib_warning ("ack invalid");
2215 * 2. check the RST bit
2220 /* If ACK is acceptable, signal client that peer is not
2221 * willing to accept connection and drop connection*/
2223 tcp_connection_reset (tc0);
2228 * 3. check the security and precedence (skipped)
2232 * 4. check the SYN bit
2235 /* No SYN flag. Drop. */
2236 if (!tcp_syn (tcp0))
2238 clib_warning ("not synack");
2243 if (tcp_options_parse (tcp0, &tc0->rcv_opts))
2245 clib_warning ("options parse fail");
2249 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2250 * current thread pool. */
2251 pool_get (tm->connections[my_thread_index], new_tc0);
2252 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
2253 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2254 new_tc0->c_thread_index = my_thread_index;
2255 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2256 new_tc0->irs = seq0;
2257 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
2258 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] =
2259 TCP_TIMER_HANDLE_INVALID;
2260 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2262 /* If this is not the owning thread, wait for syn retransmit to
2263 * expire and cleanup then */
2264 if (tcp_half_open_connection_cleanup (tc0))
2265 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2267 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2269 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2270 new_tc0->tsval_recent_age = tcp_time_now ();
2273 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2274 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2276 /* RFC1323: SYN and SYN-ACK wnd not scaled */
2277 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window);
2278 new_tc0->snd_wl1 = seq0;
2279 new_tc0->snd_wl2 = ack0;
2281 tcp_connection_init_vars (new_tc0);
2283 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2284 if (PREDICT_TRUE (tcp_ack (tcp0)))
2286 /* Our SYN is ACKed: we have iss < ack = snd_una */
2288 /* TODO Dequeue acknowledged segments if we support Fast Open */
2289 new_tc0->snd_una = ack0;
2290 new_tc0->state = TCP_STATE_ESTABLISHED;
2292 /* Make sure las is initialized for the wnd computation */
2293 new_tc0->rcv_las = new_tc0->rcv_nxt;
2295 /* Notify app that we have connection. If session layer can't
2296 * allocate session send reset */
2297 if (session_stream_connect_notify (&new_tc0->connection, 0))
2299 clib_warning ("connect notify fail");
2300 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2301 tcp_connection_cleanup (new_tc0);
2305 /* Make sure after data segment processing ACK is sent */
2306 new_tc0->flags |= TCP_CONN_SNDACK;
2308 /* Update rtt with the syn-ack sample */
2309 tcp_update_rtt (new_tc0, vnet_buffer (b0)->tcp.ack_number);
2310 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2312 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2315 new_tc0->state = TCP_STATE_SYN_RCVD;
2317 /* Notify app that we have connection */
2318 if (session_stream_connect_notify (&new_tc0->connection, 0))
2320 tcp_connection_cleanup (new_tc0);
2321 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2322 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2327 tcp_init_snd_vars (tc0);
2328 tcp_make_synack (new_tc0, b0);
2329 next0 = tcp_next_output (is_ip4);
2334 /* Read data, if any */
2335 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2337 clib_warning ("rcvd data in syn-sent");
2338 error0 = tcp_segment_rcv (new_tc0, b0, &next0);
2339 if (error0 == TCP_ERROR_ACK_OK)
2340 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2341 tcp_maybe_inc_counter (syn_sent, error0, 1);
2345 tcp_make_ack (new_tc0, b0);
2346 next0 = tcp_next_output (new_tc0->c_is_ip4);
2351 b0->error = error0 ? node->errors[error0] : 0;
2353 ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2355 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2356 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2357 clib_memcpy (&t0->tcp_connection, tc0,
2358 sizeof (t0->tcp_connection));
2361 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2362 n_left_to_next, bi0, next0);
2365 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2368 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2370 tcp_inc_counter (syn_sent, TCP_ERROR_EVENT_FIFO_FULL, errors);
2371 return from_frame->n_vectors;
2375 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2376 vlib_frame_t * from_frame)
2378 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2382 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2383 vlib_frame_t * from_frame)
2385 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2389 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2391 .function = tcp4_syn_sent,
2392 .name = "tcp4-syn-sent",
2393 /* Takes a vector of packets. */
2394 .vector_size = sizeof (u32),
2395 .n_errors = TCP_N_ERROR,
2396 .error_strings = tcp_error_strings,
2397 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2400 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2401 foreach_tcp_state_next
2404 .format_trace = format_tcp_rx_trace_short,
2408 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2411 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2413 .function = tcp6_syn_sent_rcv,
2414 .name = "tcp6-syn-sent",
2415 /* Takes a vector of packets. */
2416 .vector_size = sizeof (u32),
2417 .n_errors = TCP_N_ERROR,
2418 .error_strings = tcp_error_strings,
2419 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2422 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2423 foreach_tcp_state_next
2426 .format_trace = format_tcp_rx_trace_short,
2430 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2432 vlib_node_registration_t tcp4_rcv_process_node;
2433 vlib_node_registration_t tcp6_rcv_process_node;
2436 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2437 * as per RFC793 p. 64
2440 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2441 vlib_frame_t * from_frame, int is_ip4)
2443 u32 n_left_from, next_index, *from, *to_next, n_fins = 0;
2444 u32 my_thread_index = vm->thread_index, errors = 0;
2446 from = vlib_frame_vector_args (from_frame);
2447 n_left_from = from_frame->n_vectors;
2448 next_index = node->cached_next_index;
2450 while (n_left_from > 0)
2454 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2456 while (n_left_from > 0 && n_left_to_next > 0)
2460 tcp_header_t *tcp0 = 0;
2461 tcp_connection_t *tc0;
2462 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_NONE;
2470 n_left_to_next -= 1;
2472 b0 = vlib_get_buffer (vm, bi0);
2473 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2475 if (PREDICT_FALSE (tc0 == 0))
2477 error0 = TCP_ERROR_INVALID_CONNECTION;
2481 tcp0 = tcp_buffer_hdr (b0);
2482 is_fin0 = tcp_is_fin (tcp0);
2484 /* SYNs, FINs and data consume sequence numbers */
2485 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2486 + tcp_is_syn (tcp0) + is_fin0 + vnet_buffer (b0)->tcp.data_len;
2490 tcp_connection_t *tmp;
2491 tmp = tcp_lookup_connection (tc0->c_fib_index, b0,
2492 my_thread_index, is_ip4);
2493 if (tmp->state != tc0->state)
2495 clib_warning ("state changed");
2501 * Special treatment for CLOSED
2503 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2505 error0 = TCP_ERROR_CONNECTION_CLOSED;
2510 * For all other states (except LISTEN)
2513 /* 1-4: check SEQ, RST, SYN */
2514 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, tcp0,
2517 tcp_maybe_inc_counter (rcv_process, error0, 1);
2521 /* 5: check the ACK field */
2524 case TCP_STATE_SYN_RCVD:
2526 * If the segment acknowledgment is not acceptable, form a
2528 * <SEQ=SEG.ACK><CTL=RST>
2531 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2533 TCP_DBG ("connection not accepted");
2534 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2535 error0 = TCP_ERROR_ACK_INVALID;
2539 /* Update rtt and rto */
2540 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
2542 /* Switch state to ESTABLISHED */
2543 tc0->state = TCP_STATE_ESTABLISHED;
2544 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2546 /* Initialize session variables */
2547 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2548 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2549 << tc0->rcv_opts.wscale;
2550 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2551 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2553 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2554 tcp_retransmit_timer_reset (tc0);
2555 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2556 stream_session_accept_notify (&tc0->connection);
2557 error0 = TCP_ERROR_ACK_OK;
2559 case TCP_STATE_ESTABLISHED:
2560 /* We can get packets in established state here because they
2561 * were enqueued before state change */
2562 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2564 tcp_maybe_inc_counter (rcv_process, error0, 1);
2569 case TCP_STATE_FIN_WAIT_1:
2570 /* In addition to the processing for the ESTABLISHED state, if
2571 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2572 * continue processing in that state. */
2573 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2575 tcp_maybe_inc_counter (rcv_process, error0, 1);
2579 /* Still have to send the FIN */
2580 if (tc0->flags & TCP_CONN_FINPNDG)
2582 /* TX fifo finally drained */
2583 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2586 /* If FIN is ACKed */
2587 else if (tc0->snd_una == tc0->snd_una_max)
2589 tc0->state = TCP_STATE_FIN_WAIT_2;
2590 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2592 /* Stop all retransmit timers because we have nothing more
2593 * to send. Enable waitclose though because we're willing to
2594 * wait for peer's FIN but not indefinitely. */
2595 tcp_connection_timers_reset (tc0);
2596 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2599 case TCP_STATE_FIN_WAIT_2:
2600 /* In addition to the processing for the ESTABLISHED state, if
2601 * the retransmission queue is empty, the user's CLOSE can be
2602 * acknowledged ("ok") but do not delete the TCB. */
2603 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2605 tcp_maybe_inc_counter (rcv_process, error0, 1);
2609 case TCP_STATE_CLOSE_WAIT:
2610 /* Do the same processing as for the ESTABLISHED state. */
2611 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2613 tcp_maybe_inc_counter (rcv_process, error0, 1);
2616 if (tc0->flags & TCP_CONN_FINPNDG)
2618 /* TX fifo finally drained */
2619 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2622 tcp_connection_timers_reset (tc0);
2623 tc0->state = TCP_STATE_LAST_ACK;
2624 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2629 case TCP_STATE_CLOSING:
2630 /* In addition to the processing for the ESTABLISHED state, if
2631 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2632 * otherwise ignore the segment. */
2633 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2635 tcp_maybe_inc_counter (rcv_process, error0, 1);
2639 tc0->state = TCP_STATE_TIME_WAIT;
2640 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2641 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2645 case TCP_STATE_LAST_ACK:
2646 /* The only thing that [should] arrive in this state is an
2647 * acknowledgment of our FIN. If our FIN is now acknowledged,
2648 * delete the TCB, enter the CLOSED state, and return. */
2650 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2652 error0 = TCP_ERROR_ACK_INVALID;
2655 error0 = TCP_ERROR_ACK_OK;
2656 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2657 /* Apparently our ACK for the peer's FIN was lost */
2658 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2664 tc0->state = TCP_STATE_CLOSED;
2665 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2666 /* Delete the connection/session since the pipes should be
2668 tcp_connection_del (tc0);
2673 case TCP_STATE_TIME_WAIT:
2674 /* The only thing that can arrive in this state is a
2675 * retransmission of the remote FIN. Acknowledge it, and restart
2676 * the 2 MSL timeout. */
2678 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2680 tcp_maybe_inc_counter (rcv_process, error0, 1);
2684 tcp_make_ack (tc0, b0);
2685 next0 = tcp_next_output (is_ip4);
2686 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2694 /* 6: check the URG bit TODO */
2696 /* 7: process the segment text */
2699 case TCP_STATE_ESTABLISHED:
2700 case TCP_STATE_FIN_WAIT_1:
2701 case TCP_STATE_FIN_WAIT_2:
2702 if (vnet_buffer (b0)->tcp.data_len)
2704 error0 = tcp_segment_rcv (tc0, b0, &next0);
2705 tcp_maybe_inc_counter (rcv_process, error0, 1);
2710 case TCP_STATE_CLOSE_WAIT:
2711 case TCP_STATE_CLOSING:
2712 case TCP_STATE_LAST_ACK:
2713 case TCP_STATE_TIME_WAIT:
2714 /* This should not occur, since a FIN has been received from the
2715 * remote side. Ignore the segment text. */
2719 /* 8: check the FIN bit */
2725 case TCP_STATE_ESTABLISHED:
2726 case TCP_STATE_SYN_RCVD:
2727 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2728 tcp_connection_timers_reset (tc0);
2729 tcp_retransmit_timer_set (tc0);
2730 tcp_make_fin (tc0, b0);
2732 tc0->snd_una_max = tc0->snd_nxt;
2733 next0 = tcp_next_output (tc0->c_is_ip4);
2734 stream_session_disconnect_notify (&tc0->connection);
2735 tc0->state = TCP_STATE_CLOSE_WAIT;
2736 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2738 case TCP_STATE_CLOSE_WAIT:
2739 case TCP_STATE_CLOSING:
2740 case TCP_STATE_LAST_ACK:
2743 case TCP_STATE_FIN_WAIT_1:
2744 tc0->state = TCP_STATE_CLOSING;
2745 tcp_make_ack (tc0, b0);
2746 next0 = tcp_next_output (is_ip4);
2747 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2748 /* Wait for ACK but not forever */
2749 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2751 case TCP_STATE_FIN_WAIT_2:
2752 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2753 tc0->state = TCP_STATE_TIME_WAIT;
2754 tcp_connection_timers_reset (tc0);
2755 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2756 tcp_make_ack (tc0, b0);
2757 next0 = tcp_next_output (is_ip4);
2758 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2760 case TCP_STATE_TIME_WAIT:
2761 /* Remain in the TIME-WAIT state. Restart the time-wait
2764 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2767 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2771 b0->error = error0 ? node->errors[error0] : 0;
2773 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2775 tcp_rx_trace_t *t0 =
2776 vlib_add_trace (vm, node, b0, sizeof (*t0));
2777 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2780 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2781 n_left_to_next, bi0, next0);
2784 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2787 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2789 tcp_inc_counter (rcv_process, TCP_ERROR_EVENT_FIFO_FULL, errors);
2790 tcp_inc_counter (rcv_process, TCP_ERROR_FIN_RCVD, n_fins);
2791 return from_frame->n_vectors;
2795 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2796 vlib_frame_t * from_frame)
2798 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2802 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2803 vlib_frame_t * from_frame)
2805 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2809 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2811 .function = tcp4_rcv_process,
2812 .name = "tcp4-rcv-process",
2813 /* Takes a vector of packets. */
2814 .vector_size = sizeof (u32),
2815 .n_errors = TCP_N_ERROR,
2816 .error_strings = tcp_error_strings,
2817 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2820 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2821 foreach_tcp_state_next
2824 .format_trace = format_tcp_rx_trace_short,
2828 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2831 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2833 .function = tcp6_rcv_process,
2834 .name = "tcp6-rcv-process",
2835 /* Takes a vector of packets. */
2836 .vector_size = sizeof (u32),
2837 .n_errors = TCP_N_ERROR,
2838 .error_strings = tcp_error_strings,
2839 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2842 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2843 foreach_tcp_state_next
2846 .format_trace = format_tcp_rx_trace_short,
2850 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2852 vlib_node_registration_t tcp4_listen_node;
2853 vlib_node_registration_t tcp6_listen_node;
2856 * LISTEN state processing as per RFC 793 p. 65
2859 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2860 vlib_frame_t * from_frame, int is_ip4)
2862 u32 n_left_from, next_index, *from, *to_next, n_syns = 0;
2863 u32 my_thread_index = vm->thread_index;
2865 from = vlib_frame_vector_args (from_frame);
2866 n_left_from = from_frame->n_vectors;
2868 next_index = node->cached_next_index;
2870 while (n_left_from > 0)
2874 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2876 while (n_left_from > 0 && n_left_to_next > 0)
2881 tcp_header_t *th0 = 0;
2882 tcp_connection_t *lc0;
2885 tcp_connection_t *child0;
2886 u32 error0 = TCP_ERROR_NONE, next0 = tcp_next_drop (is_ip4);
2893 n_left_to_next -= 1;
2895 b0 = vlib_get_buffer (vm, bi0);
2896 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2900 ip40 = vlib_buffer_get_current (b0);
2901 th0 = ip4_next_header (ip40);
2905 ip60 = vlib_buffer_get_current (b0);
2906 th0 = ip6_next_header (ip60);
2909 /* Create child session. For syn-flood protection use filter */
2911 /* 1. first check for an RST: handled in dispatch */
2912 /* if (tcp_rst (th0))
2915 /* 2. second check for an ACK: handled in dispatch */
2916 /* if (tcp_ack (th0))
2918 tcp_send_reset (b0, is_ip4);
2922 /* 3. check for a SYN (did that already) */
2924 /* Make sure connection wasn't just created */
2925 child0 = tcp_lookup_connection (lc0->c_fib_index, b0,
2926 my_thread_index, is_ip4);
2927 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
2929 error0 = TCP_ERROR_CREATE_EXISTS;
2933 /* Create child session and send SYN-ACK */
2934 child0 = tcp_connection_new (my_thread_index);
2935 child0->c_lcl_port = th0->dst_port;
2936 child0->c_rmt_port = th0->src_port;
2937 child0->c_is_ip4 = is_ip4;
2938 child0->state = TCP_STATE_SYN_RCVD;
2939 child0->c_fib_index = lc0->c_fib_index;
2943 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
2944 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
2948 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
2949 sizeof (ip6_address_t));
2950 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
2951 sizeof (ip6_address_t));
2954 if (tcp_options_parse (th0, &child0->rcv_opts))
2956 clib_warning ("options parse fail");
2960 child0->irs = vnet_buffer (b0)->tcp.seq_number;
2961 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
2962 child0->rcv_las = child0->rcv_nxt;
2963 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2965 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
2966 * segments are used to initialize PAWS. */
2967 if (tcp_opts_tstamp (&child0->rcv_opts))
2969 child0->tsval_recent = child0->rcv_opts.tsval;
2970 child0->tsval_recent_age = tcp_time_now ();
2973 if (tcp_opts_wscale (&child0->rcv_opts))
2974 child0->snd_wscale = child0->rcv_opts.wscale;
2976 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
2977 << child0->snd_wscale;
2978 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2979 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2981 tcp_connection_init_vars (child0);
2982 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
2984 if (stream_session_accept (&child0->connection, lc0->c_s_index,
2987 clib_warning ("session accept fail");
2988 tcp_connection_cleanup (child0);
2989 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2993 /* Reuse buffer to make syn-ack and send */
2994 tcp_make_synack (child0, b0);
2995 next0 = tcp_next_output (is_ip4);
2996 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
2999 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3001 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3002 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3003 clib_memcpy (&t0->tcp_connection, lc0,
3004 sizeof (t0->tcp_connection));
3007 n_syns += (error0 == TCP_ERROR_NONE);
3008 b0->error = node->errors[error0];
3010 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
3011 n_left_to_next, bi0, next0);
3014 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
3017 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3018 return from_frame->n_vectors;
3022 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3023 vlib_frame_t * from_frame)
3025 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3029 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3030 vlib_frame_t * from_frame)
3032 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3036 VLIB_REGISTER_NODE (tcp4_listen_node) =
3038 .function = tcp4_listen,
3039 .name = "tcp4-listen",
3040 /* Takes a vector of packets. */
3041 .vector_size = sizeof (u32),
3042 .n_errors = TCP_N_ERROR,
3043 .error_strings = tcp_error_strings,
3044 .n_next_nodes = TCP_LISTEN_N_NEXT,
3047 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3048 foreach_tcp_state_next
3051 .format_trace = format_tcp_rx_trace_short,
3055 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
3058 VLIB_REGISTER_NODE (tcp6_listen_node) =
3060 .function = tcp6_listen,
3061 .name = "tcp6-listen",
3062 /* Takes a vector of packets. */
3063 .vector_size = sizeof (u32),
3064 .n_errors = TCP_N_ERROR,
3065 .error_strings = tcp_error_strings,
3066 .n_next_nodes = TCP_LISTEN_N_NEXT,
3069 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3070 foreach_tcp_state_next
3073 .format_trace = format_tcp_rx_trace_short,
3077 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
3079 vlib_node_registration_t tcp4_input_node;
3080 vlib_node_registration_t tcp6_input_node;
3082 typedef enum _tcp_input_next
3084 TCP_INPUT_NEXT_DROP,
3085 TCP_INPUT_NEXT_LISTEN,
3086 TCP_INPUT_NEXT_RCV_PROCESS,
3087 TCP_INPUT_NEXT_SYN_SENT,
3088 TCP_INPUT_NEXT_ESTABLISHED,
3089 TCP_INPUT_NEXT_RESET,
3090 TCP_INPUT_NEXT_PUNT,
3094 #define foreach_tcp4_input_next \
3095 _ (DROP, "ip4-drop") \
3096 _ (LISTEN, "tcp4-listen") \
3097 _ (RCV_PROCESS, "tcp4-rcv-process") \
3098 _ (SYN_SENT, "tcp4-syn-sent") \
3099 _ (ESTABLISHED, "tcp4-established") \
3100 _ (RESET, "tcp4-reset") \
3101 _ (PUNT, "ip4-punt")
3103 #define foreach_tcp6_input_next \
3104 _ (DROP, "ip6-drop") \
3105 _ (LISTEN, "tcp6-listen") \
3106 _ (RCV_PROCESS, "tcp6-rcv-process") \
3107 _ (SYN_SENT, "tcp6-syn-sent") \
3108 _ (ESTABLISHED, "tcp6-established") \
3109 _ (RESET, "tcp6-reset") \
3110 _ (PUNT, "ip6-punt")
3112 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3115 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3116 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3118 tcp_connection_t *tc;
3123 for (i = 0; i < n_bufs; i++)
3125 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3127 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3128 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3130 tcp = vlib_buffer_get_current (bs[i]);
3131 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3137 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3139 if (*error == TCP_ERROR_FILTERED)
3141 *next = TCP_INPUT_NEXT_DROP;
3143 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3145 *next = TCP_INPUT_NEXT_PUNT;
3146 *error = TCP_ERROR_PUNT;
3150 *next = TCP_INPUT_NEXT_RESET;
3151 *error = TCP_ERROR_NO_LISTENER;
3155 static inline tcp_connection_t *
3156 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3159 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3160 int n_advance_bytes, n_data_bytes;
3161 transport_connection_t *tc;
3167 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3168 tcp = ip4_next_header (ip4);
3169 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3170 n_advance_bytes = (ip4_header_bytes (ip4) + tcp_header_bytes (tcp));
3171 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3173 /* Length check. Checksum computed by ipx_local no need to compute again */
3174 if (PREDICT_FALSE (n_advance_bytes < 0))
3176 *error = TCP_ERROR_LENGTH;
3180 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3181 &ip4->src_address, tcp->dst_port,
3182 tcp->src_port, TRANSPORT_PROTO_TCP,
3183 thread_index, &is_filtered);
3187 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3188 tcp = ip6_next_header (ip6);
3189 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3190 n_advance_bytes = tcp_header_bytes (tcp);
3191 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3193 n_advance_bytes += sizeof (ip6[0]);
3195 if (PREDICT_FALSE (n_advance_bytes < 0))
3197 *error = TCP_ERROR_LENGTH;
3201 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3202 &ip6->src_address, tcp->dst_port,
3203 tcp->src_port, TRANSPORT_PROTO_TCP,
3204 thread_index, &is_filtered);
3207 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3208 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3209 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3210 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3211 vnet_buffer (b)->tcp.flags = 0;
3213 *error = is_filtered ? TCP_ERROR_FILTERED : *error;
3215 return tcp_get_connection_from_transport (tc);
3219 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3220 vlib_buffer_t * b, u16 * next, u32 * error)
3225 tcp = tcp_buffer_hdr (b);
3226 flags = tcp->flags & filter_flags;
3227 *next = tm->dispatch_table[tc->state][flags].next;
3228 *error = tm->dispatch_table[tc->state][flags].error;
3230 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3231 || *next == TCP_INPUT_NEXT_RESET))
3233 /* Overload tcp flags to store state */
3234 tcp_state_t state = tc->state;
3235 vnet_buffer (b)->tcp.flags = tc->state;
3237 if (*error == TCP_ERROR_DISPATCH)
3238 clib_warning ("disp error state %U flags %U", format_tcp_state,
3239 state, format_tcp_flags, (int) flags);
3244 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3245 vlib_frame_t * frame, int is_ip4)
3247 u32 n_left_from, *from, thread_index = vm->thread_index;
3248 tcp_main_t *tm = vnet_get_tcp_main ();
3249 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3250 u16 nexts[VLIB_FRAME_SIZE], *next;
3252 tcp_set_time_now (thread_index);
3254 from = vlib_frame_vector_args (frame);
3255 n_left_from = frame->n_vectors;
3256 vlib_get_buffers (vm, from, bufs, n_left_from);
3261 while (n_left_from >= 4)
3263 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3264 tcp_connection_t *tc0, *tc1;
3267 vlib_prefetch_buffer_header (b[2], STORE);
3268 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3270 vlib_prefetch_buffer_header (b[3], STORE);
3271 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3274 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3276 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3277 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4);
3279 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3281 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3282 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3284 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3285 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3287 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3288 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3292 if (PREDICT_TRUE (tc0 != 0))
3294 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3295 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3296 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3299 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3301 if (PREDICT_TRUE (tc1 != 0))
3303 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3304 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3305 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3308 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3315 while (n_left_from > 0)
3317 tcp_connection_t *tc0;
3318 u32 error0 = TCP_ERROR_NO_LISTENER;
3320 if (n_left_from > 1)
3322 vlib_prefetch_buffer_header (b[1], STORE);
3323 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3326 next[0] = TCP_INPUT_NEXT_DROP;
3327 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3328 if (PREDICT_TRUE (tc0 != 0))
3330 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3331 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3332 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3335 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3342 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3343 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3345 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3346 return frame->n_vectors;
3350 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3351 vlib_frame_t * from_frame)
3353 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3357 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3358 vlib_frame_t * from_frame)
3360 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3364 VLIB_REGISTER_NODE (tcp4_input_node) =
3366 .function = tcp4_input,
3367 .name = "tcp4-input",
3368 /* Takes a vector of packets. */
3369 .vector_size = sizeof (u32),
3370 .n_errors = TCP_N_ERROR,
3371 .error_strings = tcp_error_strings,
3372 .n_next_nodes = TCP_INPUT_N_NEXT,
3375 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3376 foreach_tcp4_input_next
3379 .format_buffer = format_tcp_header,
3380 .format_trace = format_tcp_rx_trace,
3384 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3387 VLIB_REGISTER_NODE (tcp6_input_node) =
3389 .function = tcp6_input,
3390 .name = "tcp6-input",
3391 /* Takes a vector of packets. */
3392 .vector_size = sizeof (u32),
3393 .n_errors = TCP_N_ERROR,
3394 .error_strings = tcp_error_strings,
3395 .n_next_nodes = TCP_INPUT_N_NEXT,
3398 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3399 foreach_tcp6_input_next
3402 .format_buffer = format_tcp_header,
3403 .format_trace = format_tcp_rx_trace,
3407 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3410 tcp_dispatch_table_init (tcp_main_t * tm)
3413 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3414 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3416 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3417 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3420 #define _(t,f,n,e) \
3422 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3423 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3426 /* SYNs for new connections -> tcp-listen. */
3427 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3428 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3429 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_RST_RCVD);
3430 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3432 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3433 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3434 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3435 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3436 /* SYN-ACK for a SYN */
3437 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3439 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3440 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3441 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3443 /* ACK for for established connection -> tcp-established. */
3444 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3445 /* FIN for for established connection -> tcp-established. */
3446 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3447 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3449 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3450 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3452 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3453 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3455 /* ACK or FIN-ACK to our FIN */
3456 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3457 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3459 /* FIN in reply to our FIN from the other side */
3460 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3461 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3462 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3463 /* FIN confirming that the peer (app) has closed */
3464 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3465 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3466 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3468 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3469 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3471 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3472 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3473 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3475 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3476 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3477 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3479 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3480 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3481 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3482 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3483 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3484 TCP_ERROR_CONNECTION_CLOSED);
3488 static clib_error_t *
3489 tcp_input_init (vlib_main_t * vm)
3491 clib_error_t *error = 0;
3492 tcp_main_t *tm = vnet_get_tcp_main ();
3494 if ((error = vlib_call_init_function (vm, tcp_init)))
3497 /* Initialize dispatch table. */
3498 tcp_dispatch_table_init (tm);
3503 VLIB_INIT_FUNCTION (tcp_input_init);
3506 * fd.io coding-style-patch-verification: ON
3509 * eval: (c-set-style "gnu")