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;
827 old_sacked_bytes = sb->sacked_bytes;
828 sb->last_bytes_delivered = 0;
830 if (!tcp_opts_sack (&tc->rcv_opts)
831 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
834 /* Remove invalid blocks */
835 blk = tc->rcv_opts.sacks;
836 while (blk < vec_end (tc->rcv_opts.sacks))
838 if (seq_lt (blk->start, blk->end)
839 && seq_gt (blk->start, tc->snd_una)
840 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_una_max))
845 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
848 /* Add block for cumulative ack */
849 if (seq_gt (ack, tc->snd_una))
851 tmp.start = tc->snd_una;
853 vec_add1 (tc->rcv_opts.sacks, tmp);
856 if (vec_len (tc->rcv_opts.sacks) == 0)
859 tcp_scoreboard_trace_add (tc, ack);
861 /* Make sure blocks are ordered */
862 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
863 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
864 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
866 tmp = tc->rcv_opts.sacks[i];
867 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
868 tc->rcv_opts.sacks[j] = tmp;
871 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
873 /* If no holes, insert the first that covers all outstanding bytes */
874 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
875 tc->snd_una, tc->snd_una_max);
876 sb->tail = scoreboard_hole_index (sb, last_hole);
877 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
878 sb->high_sacked = tmp.end;
882 /* If we have holes but snd_una_max is beyond the last hole, update
884 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
885 last_hole = scoreboard_last_hole (sb);
886 if (seq_gt (tc->snd_una_max, last_hole->end))
888 if (seq_geq (last_hole->start, sb->high_sacked))
890 last_hole->end = tc->snd_una_max;
892 /* New hole after high sacked block */
893 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
895 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
899 /* Keep track of max byte sacked for when the last hole
901 if (seq_gt (tmp.end, sb->high_sacked))
902 sb->high_sacked = tmp.end;
905 /* Walk the holes with the SACK blocks */
906 hole = pool_elt_at_index (sb->holes, sb->head);
907 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
909 blk = &tc->rcv_opts.sacks[blk_index];
910 if (seq_leq (blk->start, hole->start))
912 /* Block covers hole. Remove hole */
913 if (seq_geq (blk->end, hole->end))
915 next_hole = scoreboard_next_hole (sb, hole);
917 /* Byte accounting: snd_una needs to be advanced */
922 if (seq_lt (ack, next_hole->start))
923 sb->snd_una_adv = next_hole->start - ack;
924 sb->last_bytes_delivered +=
925 next_hole->start - hole->end;
929 ASSERT (seq_geq (sb->high_sacked, ack));
930 sb->snd_una_adv = sb->high_sacked - ack;
931 sb->last_bytes_delivered += sb->high_sacked - hole->end;
935 scoreboard_remove_hole (sb, hole);
938 /* Partial 'head' overlap */
941 if (seq_gt (blk->end, hole->start))
943 hole->start = blk->end;
950 /* Hole must be split */
951 if (seq_lt (blk->end, hole->end))
953 hole_index = scoreboard_hole_index (sb, hole);
954 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
957 /* Pool might've moved */
958 hole = scoreboard_get_hole (sb, hole_index);
959 hole->end = blk->start;
961 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
963 else if (seq_lt (blk->start, hole->end))
965 hole->end = blk->start;
967 hole = scoreboard_next_hole (sb, hole);
971 scoreboard_update_bytes (tc, sb);
972 sb->last_sacked_bytes = sb->sacked_bytes
973 - (old_sacked_bytes - sb->last_bytes_delivered);
974 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
975 ASSERT (sb->sacked_bytes == 0
976 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
977 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
978 - seq_max (tc->snd_una, ack));
979 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
980 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
981 TCP_EVT_DBG (TCP_EVT_CC_SCOREBOARD, tc);
985 * Try to update snd_wnd based on feedback received from peer.
987 * If successful, and new window is 'effectively' 0, activate persist
991 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
993 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
994 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
995 if (seq_lt (tc->snd_wl1, seq)
996 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
998 tc->snd_wnd = snd_wnd;
1001 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
1003 if (tc->snd_wnd < tc->snd_mss)
1005 /* Set persist timer if not set and we just got 0 wnd */
1006 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1007 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1008 tcp_persist_timer_set (tc);
1012 tcp_persist_timer_reset (tc);
1013 if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
1016 tcp_update_rto (tc);
1023 * Init loss recovery/fast recovery.
1025 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1026 * updated in @ref tcp_cc_handle_event after fast retransmit
1029 tcp_cc_init_congestion (tcp_connection_t * tc)
1031 tcp_fastrecovery_on (tc);
1032 tc->snd_congestion = tc->snd_una_max;
1033 tc->cwnd_acc_bytes = 0;
1034 tc->cc_algo->congestion (tc);
1035 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
1039 tcp_cc_recovery_exit (tcp_connection_t * tc)
1042 tcp_update_rto (tc);
1044 tc->snd_nxt = tc->snd_una_max;
1045 tcp_recovery_off (tc);
1046 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1050 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
1052 tc->cc_algo->recovered (tc);
1053 tc->snd_rxt_bytes = 0;
1054 tc->rcv_dupacks = 0;
1055 tc->snd_nxt = tc->snd_una_max;
1056 tcp_fastrecovery_off (tc);
1057 tcp_fastrecovery_1_smss_off (tc);
1058 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1062 tcp_cc_congestion_undo (tcp_connection_t * tc)
1064 tc->cwnd = tc->prev_cwnd;
1065 tc->ssthresh = tc->prev_ssthresh;
1066 tc->snd_nxt = tc->snd_una_max;
1067 tc->rcv_dupacks = 0;
1068 if (tcp_in_recovery (tc))
1069 tcp_cc_recovery_exit (tc);
1070 ASSERT (tc->rto_boff == 0);
1071 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
1072 /* TODO extend for fastrecovery */
1076 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1078 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1080 && tcp_opts_tstamp (&tc->rcv_opts)
1081 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1085 tcp_cc_recover (tcp_connection_t * tc)
1087 ASSERT (tcp_in_cong_recovery (tc));
1088 if (tcp_cc_is_spurious_retransmit (tc))
1090 tcp_cc_congestion_undo (tc);
1094 if (tcp_in_recovery (tc))
1095 tcp_cc_recovery_exit (tc);
1096 else if (tcp_in_fastrecovery (tc))
1097 tcp_cc_fastrecovery_exit (tc);
1099 ASSERT (tc->rto_boff == 0);
1100 ASSERT (!tcp_in_cong_recovery (tc));
1101 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1106 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
1108 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1110 /* Congestion avoidance */
1111 tc->cc_algo->rcv_ack (tc);
1112 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1114 /* If a cumulative ack, make sure dupacks is 0 */
1115 tc->rcv_dupacks = 0;
1117 /* When dupacks hits the threshold we only enter fast retransmit if
1118 * cumulative ack covers more than snd_congestion. Should snd_una
1119 * wrap this test may fail under otherwise valid circumstances.
1120 * Therefore, proactively update snd_congestion when wrap detected. */
1122 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1123 && seq_gt (tc->snd_congestion, tc->snd_una)))
1124 tc->snd_congestion = tc->snd_una - 1;
1128 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1130 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1134 tcp_should_fastrecover (tcp_connection_t * tc)
1136 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1137 || tcp_should_fastrecover_sack (tc));
1141 * One function to rule them all ... and in the darkness bind them
1144 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1148 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1150 if (tc->bytes_acked)
1152 tcp_fast_retransmit (tc);
1156 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1157 * it account for the bytes that left the network.
1159 else if (is_dack && !tcp_in_recovery (tc))
1161 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1162 ASSERT (tc->snd_una != tc->snd_una_max
1163 || tc->sack_sb.last_sacked_bytes);
1167 /* Pure duplicate ack. If some data got acked, it's handled lower */
1168 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1170 ASSERT (tcp_in_fastrecovery (tc));
1171 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1174 else if (tcp_should_fastrecover (tc))
1176 ASSERT (!tcp_in_fastrecovery (tc));
1178 /* If of of the two conditions lower hold, reset dupacks because
1179 * we're probably after timeout (RFC6582 heuristics).
1180 * If Cumulative ack does not cover more than congestion threshold,
1182 * 1) The following doesn't hold: The congestion window is greater
1183 * than SMSS bytes and the difference between highest_ack
1184 * and prev_highest_ack is at most 4*SMSS bytes
1185 * 2) Echoed timestamp in the last non-dup ack does not equal the
1188 if (seq_leq (tc->snd_una, tc->snd_congestion)
1189 && ((!(tc->cwnd > tc->snd_mss
1190 && tc->bytes_acked <= 4 * tc->snd_mss))
1191 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1193 tc->rcv_dupacks = 0;
1197 tcp_cc_init_congestion (tc);
1198 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1200 /* The first segment MUST be retransmitted */
1201 tcp_retransmit_first_unacked (tc);
1203 /* Post retransmit update cwnd to ssthresh and account for the
1204 * three segments that have left the network and should've been
1205 * buffered at the receiver XXX */
1206 tc->cwnd = tc->ssthresh + tc->rcv_dupacks * tc->snd_mss;
1207 ASSERT (tc->cwnd >= tc->snd_mss);
1209 /* If cwnd allows, send more data */
1210 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1212 scoreboard_init_high_rxt (&tc->sack_sb,
1213 tc->snd_una + tc->snd_mss);
1214 tcp_fast_retransmit_sack (tc);
1218 tcp_fast_retransmit_no_sack (tc);
1222 else if (!tc->bytes_acked
1223 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1225 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1232 if (!tc->bytes_acked)
1236 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1239 * Legitimate ACK. 1) See if we can exit recovery
1241 /* XXX limit this only to first partial ack? */
1242 tcp_retransmit_timer_update (tc);
1244 if (seq_geq (tc->snd_una, tc->snd_congestion))
1246 /* If spurious return, we've already updated everything */
1247 if (tcp_cc_recover (tc))
1249 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1253 tc->snd_nxt = tc->snd_una_max;
1255 /* Treat as congestion avoidance ack */
1256 tc->cc_algo->rcv_ack (tc);
1257 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1262 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1265 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1266 * reset dupacks to 0. Also needed if in congestion recovery */
1267 tc->rcv_dupacks = 0;
1269 /* Post RTO timeout don't try anything fancy */
1270 if (tcp_in_recovery (tc))
1272 tc->cc_algo->rcv_ack (tc);
1273 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1277 /* Remove retransmitted bytes that have been delivered */
1278 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1279 >= tc->sack_sb.last_bytes_delivered
1280 || (tc->flags & TCP_CONN_FINSNT));
1282 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1284 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1285 * remove sacked bytes delivered */
1286 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1287 - tc->sack_sb.last_bytes_delivered;
1288 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1289 tc->snd_rxt_bytes -= rxt_delivered;
1293 /* Either all retransmitted holes have been acked, or we're
1294 * "in the blind" and retransmitting segment by segment */
1295 tc->snd_rxt_bytes = 0;
1298 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1301 * Since this was a partial ack, try to retransmit some more data
1303 tcp_fast_retransmit (tc);
1307 * Process incoming ACK
1310 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
1311 tcp_header_t * th, u32 * next, u32 * error)
1313 u32 prev_snd_wnd, prev_snd_una;
1316 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1318 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1319 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1321 /* When we entered recovery, we reset snd_nxt to snd_una. Seems peer
1322 * still has the data so accept the ack */
1323 if (tcp_in_recovery (tc)
1324 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_congestion)
1325 && seq_geq (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
1327 tc->snd_una_max = tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1331 /* If we have outstanding data and this is within the window, accept it,
1332 * probably retransmit has timed out. Otherwise ACK segment and then
1334 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1336 tcp_make_ack (tc, b);
1337 *next = tcp_next_output (tc->c_is_ip4);
1338 *error = TCP_ERROR_ACK_INVALID;
1339 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1340 vnet_buffer (b)->tcp.ack_number);
1344 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1345 vnet_buffer (b)->tcp.ack_number);
1347 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1348 *error = TCP_ERROR_ACK_FUTURE;
1351 /* If old ACK, probably it's an old dupack */
1352 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1354 *error = TCP_ERROR_ACK_OLD;
1355 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1356 vnet_buffer (b)->tcp.ack_number);
1357 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1358 tcp_cc_handle_event (tc, 1);
1359 /* Don't drop yet */
1364 * Looks okay, process feedback
1367 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1368 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1370 prev_snd_wnd = tc->snd_wnd;
1371 prev_snd_una = tc->snd_una;
1372 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1373 vnet_buffer (b)->tcp.ack_number,
1374 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1375 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1376 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1377 tcp_validate_txf_size (tc, tc->bytes_acked);
1379 if (tc->bytes_acked)
1380 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
1382 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1385 * Check if we have congestion event
1388 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1390 tcp_cc_handle_event (tc, is_dack);
1391 if (!tcp_in_cong_recovery (tc))
1393 *error = TCP_ERROR_ACK_DUP;
1394 return vnet_buffer (b)->tcp.data_len ? 0 : -1;
1398 * Update congestion control (slow start/congestion avoidance)
1400 tcp_cc_update (tc, b);
1401 *error = TCP_ERROR_ACK_OK;
1406 tcp_sack_vector_is_sane (sack_block_t * sacks)
1409 for (i = 1; i < vec_len (sacks); i++)
1411 if (sacks[i - 1].end == sacks[i].start)
1418 * Build SACK list as per RFC2018.
1420 * Makes sure the first block contains the segment that generated the current
1421 * ACK and the following ones are the ones most recently reported in SACK
1424 * @param tc TCP connection for which the SACK list is updated
1425 * @param start Start sequence number of the newest SACK block
1426 * @param end End sequence of the newest SACK block
1429 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1431 sack_block_t *new_list = 0, *block = 0;
1434 /* If the first segment is ooo add it to the list. Last write might've moved
1435 * rcv_nxt over the first segment. */
1436 if (seq_lt (tc->rcv_nxt, start))
1438 vec_add2 (new_list, block, 1);
1439 block->start = start;
1443 /* Find the blocks still worth keeping. */
1444 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1446 /* Discard if rcv_nxt advanced beyond current block */
1447 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1450 /* Merge or drop if segment overlapped by the new segment */
1451 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1452 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1454 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1455 new_list[0].start = tc->snd_sacks[i].start;
1456 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1457 new_list[0].end = tc->snd_sacks[i].end;
1461 /* Save to new SACK list if we have space. */
1462 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1464 vec_add1 (new_list, tc->snd_sacks[i]);
1468 clib_warning ("sack discarded");
1472 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1474 /* Replace old vector with new one */
1475 vec_free (tc->snd_sacks);
1476 tc->snd_sacks = new_list;
1478 /* Segments should not 'touch' */
1479 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1483 tcp_sack_list_bytes (tcp_connection_t * tc)
1486 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1487 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1491 /** Enqueue data for delivery to application */
1493 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1496 int written, error = TCP_ERROR_ENQUEUED;
1498 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1500 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1501 1 /* queue event */ , 1);
1503 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1505 /* Update rcv_nxt */
1506 if (PREDICT_TRUE (written == data_len))
1508 tc->rcv_nxt += written;
1510 /* If more data written than expected, account for out-of-order bytes. */
1511 else if (written > data_len)
1513 tc->rcv_nxt += written;
1515 /* Send ACK confirming the update */
1516 tc->flags |= TCP_CONN_SNDACK;
1517 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1519 else if (written > 0)
1521 /* We've written something but FIFO is probably full now */
1522 tc->rcv_nxt += written;
1524 /* Depending on how fast the app is, all remaining buffers in burst will
1525 * not be enqueued. Inform peer */
1526 tc->flags |= TCP_CONN_SNDACK;
1528 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1532 tc->flags |= TCP_CONN_SNDACK;
1533 return TCP_ERROR_FIFO_FULL;
1536 /* Update SACK list if need be */
1537 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1539 /* Remove SACK blocks that have been delivered */
1540 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1546 /** Enqueue out-of-order data */
1548 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1551 stream_session_t *s0;
1554 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1557 /* Enqueue out-of-order data with relative offset */
1558 rv = session_enqueue_stream_connection (&tc->connection, b,
1559 vnet_buffer (b)->tcp.seq_number -
1560 tc->rcv_nxt, 0 /* queue event */ ,
1563 /* Nothing written */
1566 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1567 return TCP_ERROR_FIFO_FULL;
1570 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1572 /* Update SACK list if in use */
1573 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1575 ooo_segment_t *newest;
1578 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1580 /* Get the newest segment from the fifo */
1581 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1584 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1585 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1586 start = tc->rcv_nxt + offset;
1587 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1588 tcp_update_sack_list (tc, start, end);
1589 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1590 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1594 return TCP_ERROR_ENQUEUED_OOO;
1598 * Check if ACK could be delayed. If ack can be delayed, it should return
1599 * true for a full frame. If we're always acking return 0.
1602 tcp_can_delack (tcp_connection_t * tc)
1604 /* Send ack if ... */
1606 /* just sent a rcv wnd 0 */
1607 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1608 /* constrained to send ack */
1609 || (tc->flags & TCP_CONN_SNDACK) != 0
1610 /* we're almost out of tx wnd */
1611 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1618 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1620 u32 discard, first = b->current_length;
1621 vlib_main_t *vm = vlib_get_main ();
1623 /* Handle multi-buffer segments */
1624 if (n_bytes_to_drop > b->current_length)
1626 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1630 discard = clib_min (n_bytes_to_drop, b->current_length);
1631 vlib_buffer_advance (b, discard);
1632 b = vlib_get_buffer (vm, b->next_buffer);
1633 n_bytes_to_drop -= discard;
1635 while (n_bytes_to_drop);
1636 if (n_bytes_to_drop > first)
1637 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1640 vlib_buffer_advance (b, n_bytes_to_drop);
1641 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1646 * Receive buffer for connection and handle acks
1648 * It handles both in order or out-of-order data.
1651 tcp_segment_rcv (tcp_connection_t * tc, vlib_buffer_t * b, u32 * next0)
1653 u32 error, n_bytes_to_drop, n_data_bytes;
1655 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1656 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1657 ASSERT (n_data_bytes);
1659 /* Handle out-of-order data */
1660 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1662 /* Old sequence numbers allowed through because they overlapped
1664 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1666 /* Completely in the past (possible retransmit). Ack
1667 * retransmissions since we may not have any data to send */
1668 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1670 tcp_make_ack (tc, b);
1671 error = TCP_ERROR_SEGMENT_OLD;
1672 *next0 = tcp_next_output (tc->c_is_ip4);
1676 /* Chop off the bytes in the past and see if what is left
1677 * can be enqueued in order */
1678 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1679 n_data_bytes -= n_bytes_to_drop;
1680 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1681 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1683 error = TCP_ERROR_SEGMENT_OLD;
1684 *next0 = tcp_next_drop (tc->c_is_ip4);
1690 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1691 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1692 *next0 = tcp_next_output (tc->c_is_ip4);
1693 tcp_make_ack (tc, b);
1694 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1695 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1701 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1702 * segments can be enqueued after fifo tail offset changes. */
1703 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1704 if (tcp_can_delack (tc))
1706 *next0 = tcp_next_drop (tc->c_is_ip4);
1707 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1708 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1712 *next0 = tcp_next_output (tc->c_is_ip4);
1713 tcp_make_ack (tc, b);
1721 tcp_header_t tcp_header;
1722 tcp_connection_t tcp_connection;
1726 format_tcp_rx_trace (u8 * s, va_list * args)
1728 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1729 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1730 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1731 u32 indent = format_get_indent (s);
1733 s = format (s, "%U\n%U%U",
1734 format_tcp_header, &t->tcp_header, 128,
1735 format_white_space, indent,
1736 format_tcp_connection, &t->tcp_connection, 1);
1742 format_tcp_rx_trace_short (u8 * s, va_list * args)
1744 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1745 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1746 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1748 s = format (s, "%d -> %d (%U)",
1749 clib_net_to_host_u16 (t->tcp_header.dst_port),
1750 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
1751 t->tcp_connection.state);
1757 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1758 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1762 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1766 th0 = tcp_buffer_hdr (b0);
1768 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1772 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
1773 vlib_frame_t * frame, u8 is_ip4)
1777 n_left = frame->n_vectors;
1778 from = vlib_frame_vector_args (frame);
1782 tcp_connection_t *tc0;
1789 b0 = vlib_get_buffer (vm, bi0);
1791 if (b0->flags & VLIB_BUFFER_IS_TRACED)
1793 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1794 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1796 th0 = tcp_buffer_hdr (b0);
1797 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1806 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
1807 u8 is_ip4, u32 evt, u32 val)
1810 vlib_node_increment_counter (vm, tcp4_node, evt, val);
1812 vlib_node_increment_counter (vm, tcp6_node, evt, val);
1815 #define tcp_maybe_inc_counter(node_id, err, count) \
1817 if (next0 != tcp_next_drop (is_ip4)) \
1818 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1819 tcp6_##node_id##_node.index, is_ip4, err, \
1822 #define tcp_inc_counter(node_id, err, count) \
1823 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1824 tcp6_##node_id##_node.index, is_ip4, \
1826 #define tcp_maybe_inc_err_counter(cnts, err) \
1828 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
1830 #define tcp_inc_err_counter(cnts, err, val) \
1834 #define tcp_store_err_counters(node_id, cnts) \
1837 for (i = 0; i < TCP_N_ERROR; i++) \
1839 tcp_inc_counter(node_id, i, cnts[i]); \
1844 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1845 vlib_frame_t * frame, int is_ip4)
1847 u32 thread_index = vm->thread_index, errors = 0;
1848 u32 n_left_from, next_index, *from, *to_next;
1849 u16 err_counters[TCP_N_ERROR] = { 0 };
1852 if (node->flags & VLIB_NODE_FLAG_TRACE)
1853 tcp_established_trace_frame (vm, node, frame, is_ip4);
1855 from = vlib_frame_vector_args (frame);
1856 n_left_from = frame->n_vectors;
1857 next_index = node->cached_next_index;
1859 while (n_left_from > 0)
1863 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1864 while (n_left_from > 0 && n_left_to_next > 0)
1868 tcp_header_t *th0 = 0;
1869 tcp_connection_t *tc0;
1870 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ACK_OK;
1872 if (n_left_from > 1)
1875 pb = vlib_get_buffer (vm, from[1]);
1876 vlib_prefetch_buffer_header (pb, LOAD);
1877 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
1885 n_left_to_next -= 1;
1887 b0 = vlib_get_buffer (vm, bi0);
1888 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1891 if (PREDICT_FALSE (tc0 == 0))
1893 error0 = TCP_ERROR_INVALID_CONNECTION;
1897 th0 = tcp_buffer_hdr (b0);
1898 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
1899 * dangling reference. */
1900 is_fin = tcp_is_fin (th0);
1902 /* SYNs, FINs and data consume sequence numbers */
1903 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1904 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
1906 /* TODO header prediction fast path */
1908 /* 1-4: check SEQ, RST, SYN */
1909 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0,
1912 tcp_maybe_inc_err_counter (err_counters, error0);
1913 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
1917 /* 5: check the ACK field */
1918 if (PREDICT_FALSE (tcp_rcv_ack (tc0, b0, th0, &next0, &error0)))
1920 tcp_maybe_inc_err_counter (err_counters, error0);
1924 /* 6: check the URG bit TODO */
1926 /* 7: process the segment text */
1927 if (vnet_buffer (b0)->tcp.data_len)
1929 error0 = tcp_segment_rcv (tc0, b0, &next0);
1930 tcp_maybe_inc_err_counter (err_counters, error0);
1933 /* 8: check the FIN bit */
1934 if (PREDICT_FALSE (is_fin))
1936 /* Enter CLOSE-WAIT and notify session. To avoid lingering
1937 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1938 /* Account for the FIN if nothing else was received */
1939 if (vnet_buffer (b0)->tcp.data_len == 0)
1941 tcp_make_ack (tc0, b0);
1942 next0 = tcp_next_output (tc0->c_is_ip4);
1943 tc0->state = TCP_STATE_CLOSE_WAIT;
1944 stream_session_disconnect_notify (&tc0->connection);
1945 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1946 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1947 tcp_inc_err_counter (err_counters, TCP_ERROR_FIN_RCVD, 1);
1951 b0->error = node->errors[error0];
1952 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1953 n_left_to_next, bi0, next0);
1956 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1959 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
1961 err_counters[TCP_ERROR_EVENT_FIFO_FULL] = errors;
1962 tcp_store_err_counters (established, err_counters);
1963 tcp_flush_frame_to_output (vm, thread_index, is_ip4);
1965 return frame->n_vectors;
1969 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1970 vlib_frame_t * from_frame)
1972 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1976 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1977 vlib_frame_t * from_frame)
1979 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1983 VLIB_REGISTER_NODE (tcp4_established_node) =
1985 .function = tcp4_established,
1986 .name = "tcp4-established",
1987 /* Takes a vector of packets. */
1988 .vector_size = sizeof (u32),
1989 .n_errors = TCP_N_ERROR,
1990 .error_strings = tcp_error_strings,
1991 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1994 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1995 foreach_tcp_state_next
1998 .format_trace = format_tcp_rx_trace_short,
2002 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
2005 VLIB_REGISTER_NODE (tcp6_established_node) =
2007 .function = tcp6_established,
2008 .name = "tcp6-established",
2009 /* Takes a vector of packets. */
2010 .vector_size = sizeof (u32),
2011 .n_errors = TCP_N_ERROR,
2012 .error_strings = tcp_error_strings,
2013 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2016 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2017 foreach_tcp_state_next
2020 .format_trace = format_tcp_rx_trace_short,
2025 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
2027 vlib_node_registration_t tcp4_syn_sent_node;
2028 vlib_node_registration_t tcp6_syn_sent_node;
2031 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2033 transport_connection_t *tmp = 0;
2040 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2043 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2044 && (tc->state == TCP_STATE_LISTEN
2045 || tc->c_rmt_port == hdr->src_port));
2049 handle = session_lookup_half_open_handle (&tc->connection);
2050 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2051 tc->c_proto, tc->c_is_ip4);
2055 if (tmp->lcl_port == hdr->dst_port
2056 && tmp->rmt_port == hdr->src_port)
2058 TCP_DBG ("half-open is valid!");
2066 * Lookup transport connection
2068 static tcp_connection_t *
2069 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2073 transport_connection_t *tconn;
2074 tcp_connection_t *tc;
2079 ip4 = vlib_buffer_get_current (b);
2080 tcp = ip4_next_header (ip4);
2081 tconn = session_lookup_connection_wt4 (fib_index,
2086 TRANSPORT_PROTO_TCP,
2087 thread_index, &is_filtered);
2088 tc = tcp_get_connection_from_transport (tconn);
2089 ASSERT (tcp_lookup_is_valid (tc, tcp));
2094 ip6 = vlib_buffer_get_current (b);
2095 tcp = ip6_next_header (ip6);
2096 tconn = session_lookup_connection_wt6 (fib_index,
2101 TRANSPORT_PROTO_TCP,
2102 thread_index, &is_filtered);
2103 tc = tcp_get_connection_from_transport (tconn);
2104 ASSERT (tcp_lookup_is_valid (tc, tcp));
2110 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2111 vlib_frame_t * from_frame, int is_ip4)
2113 tcp_main_t *tm = vnet_get_tcp_main ();
2114 u32 n_left_from, next_index, *from, *to_next;
2115 u32 my_thread_index = vm->thread_index, errors = 0;
2117 from = vlib_frame_vector_args (from_frame);
2118 n_left_from = from_frame->n_vectors;
2120 next_index = node->cached_next_index;
2122 while (n_left_from > 0)
2126 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2128 while (n_left_from > 0 && n_left_to_next > 0)
2130 u32 bi0, ack0, seq0;
2133 tcp_header_t *tcp0 = 0;
2134 tcp_connection_t *tc0;
2135 tcp_connection_t *new_tc0;
2136 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_ENQUEUED;
2143 n_left_to_next -= 1;
2145 b0 = vlib_get_buffer (vm, bi0);
2147 tcp_half_open_connection_get (vnet_buffer (b0)->
2148 tcp.connection_index);
2149 if (PREDICT_FALSE (tc0 == 0))
2151 error0 = TCP_ERROR_INVALID_CONNECTION;
2155 /* Half-open completed recently but the connection was't removed
2156 * yet by the owning thread */
2157 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2159 /* Make sure the connection actually exists */
2160 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2161 my_thread_index, is_ip4));
2165 ack0 = vnet_buffer (b0)->tcp.ack_number;
2166 seq0 = vnet_buffer (b0)->tcp.seq_number;
2167 tcp0 = tcp_buffer_hdr (b0);
2169 /* Crude check to see if the connection handle does not match
2170 * the packet. Probably connection just switched to established */
2171 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2172 || tcp0->src_port != tc0->c_rmt_port))
2176 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
2179 /* SYNs, FINs and data consume sequence numbers */
2180 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
2181 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
2184 * 1. check the ACK bit
2188 * If the ACK bit is set
2189 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2190 * the RST bit is set, if so drop the segment and return)
2191 * <SEQ=SEG.ACK><CTL=RST>
2192 * and discard the segment. Return.
2193 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2197 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2199 clib_warning ("ack not in rcv wnd");
2200 if (!tcp_rst (tcp0))
2201 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2205 /* Make sure ACK is valid */
2206 if (seq_gt (tc0->snd_una, ack0))
2208 clib_warning ("ack invalid");
2214 * 2. check the RST bit
2219 /* If ACK is acceptable, signal client that peer is not
2220 * willing to accept connection and drop connection*/
2222 tcp_connection_reset (tc0);
2227 * 3. check the security and precedence (skipped)
2231 * 4. check the SYN bit
2234 /* No SYN flag. Drop. */
2235 if (!tcp_syn (tcp0))
2237 clib_warning ("not synack");
2242 if (tcp_options_parse (tcp0, &tc0->rcv_opts))
2244 clib_warning ("options parse fail");
2248 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2249 * current thread pool. */
2250 pool_get (tm->connections[my_thread_index], new_tc0);
2251 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
2252 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2253 new_tc0->c_thread_index = my_thread_index;
2254 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2255 new_tc0->irs = seq0;
2256 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
2257 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] =
2258 TCP_TIMER_HANDLE_INVALID;
2259 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2261 /* If this is not the owning thread, wait for syn retransmit to
2262 * expire and cleanup then */
2263 if (tcp_half_open_connection_cleanup (tc0))
2264 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2266 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2268 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2269 new_tc0->tsval_recent_age = tcp_time_now ();
2272 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2273 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2275 /* RFC1323: SYN and SYN-ACK wnd not scaled */
2276 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window);
2277 new_tc0->snd_wl1 = seq0;
2278 new_tc0->snd_wl2 = ack0;
2280 tcp_connection_init_vars (new_tc0);
2282 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2283 if (PREDICT_TRUE (tcp_ack (tcp0)))
2285 /* Our SYN is ACKed: we have iss < ack = snd_una */
2287 /* TODO Dequeue acknowledged segments if we support Fast Open */
2288 new_tc0->snd_una = ack0;
2289 new_tc0->state = TCP_STATE_ESTABLISHED;
2291 /* Make sure las is initialized for the wnd computation */
2292 new_tc0->rcv_las = new_tc0->rcv_nxt;
2294 /* Notify app that we have connection. If session layer can't
2295 * allocate session send reset */
2296 if (session_stream_connect_notify (&new_tc0->connection, 0))
2298 clib_warning ("connect notify fail");
2299 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2300 tcp_connection_cleanup (new_tc0);
2304 /* Make sure after data segment processing ACK is sent */
2305 new_tc0->flags |= TCP_CONN_SNDACK;
2307 /* Update rtt with the syn-ack sample */
2308 tcp_update_rtt (new_tc0, vnet_buffer (b0)->tcp.ack_number);
2309 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2311 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2314 new_tc0->state = TCP_STATE_SYN_RCVD;
2316 /* Notify app that we have connection */
2317 if (session_stream_connect_notify (&new_tc0->connection, 0))
2319 tcp_connection_cleanup (new_tc0);
2320 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2321 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2326 tcp_init_snd_vars (tc0);
2327 tcp_make_synack (new_tc0, b0);
2328 next0 = tcp_next_output (is_ip4);
2333 /* Read data, if any */
2334 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2336 clib_warning ("rcvd data in syn-sent");
2337 error0 = tcp_segment_rcv (new_tc0, b0, &next0);
2338 if (error0 == TCP_ERROR_ACK_OK)
2339 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2340 tcp_maybe_inc_counter (syn_sent, error0, 1);
2344 tcp_make_ack (new_tc0, b0);
2345 next0 = tcp_next_output (new_tc0->c_is_ip4);
2350 b0->error = error0 ? node->errors[error0] : 0;
2352 ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2354 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2355 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2356 clib_memcpy (&t0->tcp_connection, tc0,
2357 sizeof (t0->tcp_connection));
2360 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2361 n_left_to_next, bi0, next0);
2364 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2367 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2369 tcp_inc_counter (syn_sent, TCP_ERROR_EVENT_FIFO_FULL, errors);
2370 return from_frame->n_vectors;
2374 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2375 vlib_frame_t * from_frame)
2377 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2381 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2382 vlib_frame_t * from_frame)
2384 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2388 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2390 .function = tcp4_syn_sent,
2391 .name = "tcp4-syn-sent",
2392 /* Takes a vector of packets. */
2393 .vector_size = sizeof (u32),
2394 .n_errors = TCP_N_ERROR,
2395 .error_strings = tcp_error_strings,
2396 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2399 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2400 foreach_tcp_state_next
2403 .format_trace = format_tcp_rx_trace_short,
2407 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2410 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2412 .function = tcp6_syn_sent_rcv,
2413 .name = "tcp6-syn-sent",
2414 /* Takes a vector of packets. */
2415 .vector_size = sizeof (u32),
2416 .n_errors = TCP_N_ERROR,
2417 .error_strings = tcp_error_strings,
2418 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2421 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2422 foreach_tcp_state_next
2425 .format_trace = format_tcp_rx_trace_short,
2429 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2431 vlib_node_registration_t tcp4_rcv_process_node;
2432 vlib_node_registration_t tcp6_rcv_process_node;
2435 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2436 * as per RFC793 p. 64
2439 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2440 vlib_frame_t * from_frame, int is_ip4)
2442 u32 n_left_from, next_index, *from, *to_next, n_fins = 0;
2443 u32 my_thread_index = vm->thread_index, errors = 0;
2445 from = vlib_frame_vector_args (from_frame);
2446 n_left_from = from_frame->n_vectors;
2447 next_index = node->cached_next_index;
2449 while (n_left_from > 0)
2453 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2455 while (n_left_from > 0 && n_left_to_next > 0)
2459 tcp_header_t *tcp0 = 0;
2460 tcp_connection_t *tc0;
2461 u32 next0 = tcp_next_drop (is_ip4), error0 = TCP_ERROR_NONE;
2469 n_left_to_next -= 1;
2471 b0 = vlib_get_buffer (vm, bi0);
2472 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2474 if (PREDICT_FALSE (tc0 == 0))
2476 error0 = TCP_ERROR_INVALID_CONNECTION;
2480 tcp0 = tcp_buffer_hdr (b0);
2481 is_fin0 = tcp_is_fin (tcp0);
2483 /* SYNs, FINs and data consume sequence numbers */
2484 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2485 + tcp_is_syn (tcp0) + is_fin0 + vnet_buffer (b0)->tcp.data_len;
2489 tcp_connection_t *tmp;
2490 tmp = tcp_lookup_connection (tc0->c_fib_index, b0,
2491 my_thread_index, is_ip4);
2492 if (tmp->state != tc0->state)
2494 clib_warning ("state changed");
2500 * Special treatment for CLOSED
2502 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2504 error0 = TCP_ERROR_CONNECTION_CLOSED;
2509 * For all other states (except LISTEN)
2512 /* 1-4: check SEQ, RST, SYN */
2513 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, tcp0,
2516 tcp_maybe_inc_counter (rcv_process, error0, 1);
2520 /* 5: check the ACK field */
2523 case TCP_STATE_SYN_RCVD:
2525 * If the segment acknowledgment is not acceptable, form a
2527 * <SEQ=SEG.ACK><CTL=RST>
2530 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2532 TCP_DBG ("connection not accepted");
2533 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2534 error0 = TCP_ERROR_ACK_INVALID;
2538 /* Update rtt and rto */
2539 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
2541 /* Switch state to ESTABLISHED */
2542 tc0->state = TCP_STATE_ESTABLISHED;
2543 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2545 /* Initialize session variables */
2546 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2547 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2548 << tc0->rcv_opts.wscale;
2549 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2550 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2552 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2553 tcp_retransmit_timer_reset (tc0);
2554 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2555 stream_session_accept_notify (&tc0->connection);
2556 error0 = TCP_ERROR_ACK_OK;
2558 case TCP_STATE_ESTABLISHED:
2559 /* We can get packets in established state here because they
2560 * were enqueued before state change */
2561 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2563 tcp_maybe_inc_counter (rcv_process, error0, 1);
2568 case TCP_STATE_FIN_WAIT_1:
2569 /* In addition to the processing for the ESTABLISHED state, if
2570 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2571 * continue processing in that state. */
2572 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2574 tcp_maybe_inc_counter (rcv_process, error0, 1);
2578 /* Still have to send the FIN */
2579 if (tc0->flags & TCP_CONN_FINPNDG)
2581 /* TX fifo finally drained */
2582 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2585 /* If FIN is ACKed */
2586 else if (tc0->snd_una == tc0->snd_una_max)
2588 tc0->state = TCP_STATE_FIN_WAIT_2;
2589 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2591 /* Stop all retransmit timers because we have nothing more
2592 * to send. Enable waitclose though because we're willing to
2593 * wait for peer's FIN but not indefinitely. */
2594 tcp_connection_timers_reset (tc0);
2595 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2598 case TCP_STATE_FIN_WAIT_2:
2599 /* In addition to the processing for the ESTABLISHED state, if
2600 * the retransmission queue is empty, the user's CLOSE can be
2601 * acknowledged ("ok") but do not delete the TCB. */
2602 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2604 tcp_maybe_inc_counter (rcv_process, error0, 1);
2608 case TCP_STATE_CLOSE_WAIT:
2609 /* Do the same processing as for the ESTABLISHED state. */
2610 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2612 tcp_maybe_inc_counter (rcv_process, error0, 1);
2615 if (tc0->flags & TCP_CONN_FINPNDG)
2617 /* TX fifo finally drained */
2618 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2621 tcp_connection_timers_reset (tc0);
2622 tc0->state = TCP_STATE_LAST_ACK;
2623 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE,
2628 case TCP_STATE_CLOSING:
2629 /* In addition to the processing for the ESTABLISHED state, if
2630 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2631 * otherwise ignore the segment. */
2632 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2634 tcp_maybe_inc_counter (rcv_process, error0, 1);
2638 tc0->state = TCP_STATE_TIME_WAIT;
2639 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2640 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2644 case TCP_STATE_LAST_ACK:
2645 /* The only thing that [should] arrive in this state is an
2646 * acknowledgment of our FIN. If our FIN is now acknowledged,
2647 * delete the TCB, enter the CLOSED state, and return. */
2649 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2651 error0 = TCP_ERROR_ACK_INVALID;
2654 error0 = TCP_ERROR_ACK_OK;
2655 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2656 /* Apparently our ACK for the peer's FIN was lost */
2657 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2663 tc0->state = TCP_STATE_CLOSED;
2664 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2665 /* Delete the connection/session since the pipes should be
2667 tcp_connection_del (tc0);
2672 case TCP_STATE_TIME_WAIT:
2673 /* The only thing that can arrive in this state is a
2674 * retransmission of the remote FIN. Acknowledge it, and restart
2675 * the 2 MSL timeout. */
2677 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2679 tcp_maybe_inc_counter (rcv_process, error0, 1);
2683 tcp_make_ack (tc0, b0);
2684 next0 = tcp_next_output (is_ip4);
2685 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2693 /* 6: check the URG bit TODO */
2695 /* 7: process the segment text */
2698 case TCP_STATE_ESTABLISHED:
2699 case TCP_STATE_FIN_WAIT_1:
2700 case TCP_STATE_FIN_WAIT_2:
2701 if (vnet_buffer (b0)->tcp.data_len)
2703 error0 = tcp_segment_rcv (tc0, b0, &next0);
2704 tcp_maybe_inc_counter (rcv_process, error0, 1);
2709 case TCP_STATE_CLOSE_WAIT:
2710 case TCP_STATE_CLOSING:
2711 case TCP_STATE_LAST_ACK:
2712 case TCP_STATE_TIME_WAIT:
2713 /* This should not occur, since a FIN has been received from the
2714 * remote side. Ignore the segment text. */
2718 /* 8: check the FIN bit */
2724 case TCP_STATE_ESTABLISHED:
2725 case TCP_STATE_SYN_RCVD:
2726 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2727 tcp_connection_timers_reset (tc0);
2728 tcp_retransmit_timer_set (tc0);
2729 tcp_make_fin (tc0, b0);
2731 tc0->snd_una_max = tc0->snd_nxt;
2732 next0 = tcp_next_output (tc0->c_is_ip4);
2733 stream_session_disconnect_notify (&tc0->connection);
2734 tc0->state = TCP_STATE_CLOSE_WAIT;
2735 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2737 case TCP_STATE_CLOSE_WAIT:
2738 case TCP_STATE_CLOSING:
2739 case TCP_STATE_LAST_ACK:
2742 case TCP_STATE_FIN_WAIT_1:
2743 tc0->state = TCP_STATE_CLOSING;
2744 tcp_make_ack (tc0, b0);
2745 next0 = tcp_next_output (is_ip4);
2746 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2747 /* Wait for ACK but not forever */
2748 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2750 case TCP_STATE_FIN_WAIT_2:
2751 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2752 tc0->state = TCP_STATE_TIME_WAIT;
2753 tcp_connection_timers_reset (tc0);
2754 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2755 tcp_make_ack (tc0, b0);
2756 next0 = tcp_next_output (is_ip4);
2757 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2759 case TCP_STATE_TIME_WAIT:
2760 /* Remain in the TIME-WAIT state. Restart the time-wait
2763 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2766 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2770 b0->error = error0 ? node->errors[error0] : 0;
2772 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2774 tcp_rx_trace_t *t0 =
2775 vlib_add_trace (vm, node, b0, sizeof (*t0));
2776 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2779 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2780 n_left_to_next, bi0, next0);
2783 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2786 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2788 tcp_inc_counter (rcv_process, TCP_ERROR_EVENT_FIFO_FULL, errors);
2789 tcp_inc_counter (rcv_process, TCP_ERROR_FIN_RCVD, n_fins);
2790 return from_frame->n_vectors;
2794 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2795 vlib_frame_t * from_frame)
2797 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2801 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2802 vlib_frame_t * from_frame)
2804 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2808 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2810 .function = tcp4_rcv_process,
2811 .name = "tcp4-rcv-process",
2812 /* Takes a vector of packets. */
2813 .vector_size = sizeof (u32),
2814 .n_errors = TCP_N_ERROR,
2815 .error_strings = tcp_error_strings,
2816 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2819 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2820 foreach_tcp_state_next
2823 .format_trace = format_tcp_rx_trace_short,
2827 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2830 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2832 .function = tcp6_rcv_process,
2833 .name = "tcp6-rcv-process",
2834 /* Takes a vector of packets. */
2835 .vector_size = sizeof (u32),
2836 .n_errors = TCP_N_ERROR,
2837 .error_strings = tcp_error_strings,
2838 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2841 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2842 foreach_tcp_state_next
2845 .format_trace = format_tcp_rx_trace_short,
2849 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2851 vlib_node_registration_t tcp4_listen_node;
2852 vlib_node_registration_t tcp6_listen_node;
2855 * LISTEN state processing as per RFC 793 p. 65
2858 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2859 vlib_frame_t * from_frame, int is_ip4)
2861 u32 n_left_from, next_index, *from, *to_next, n_syns = 0;
2862 u32 my_thread_index = vm->thread_index;
2864 from = vlib_frame_vector_args (from_frame);
2865 n_left_from = from_frame->n_vectors;
2867 next_index = node->cached_next_index;
2869 while (n_left_from > 0)
2873 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2875 while (n_left_from > 0 && n_left_to_next > 0)
2880 tcp_header_t *th0 = 0;
2881 tcp_connection_t *lc0;
2884 tcp_connection_t *child0;
2885 u32 error0 = TCP_ERROR_NONE, next0 = tcp_next_drop (is_ip4);
2892 n_left_to_next -= 1;
2894 b0 = vlib_get_buffer (vm, bi0);
2895 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2899 ip40 = vlib_buffer_get_current (b0);
2900 th0 = ip4_next_header (ip40);
2904 ip60 = vlib_buffer_get_current (b0);
2905 th0 = ip6_next_header (ip60);
2908 /* Create child session. For syn-flood protection use filter */
2910 /* 1. first check for an RST: handled in dispatch */
2911 /* if (tcp_rst (th0))
2914 /* 2. second check for an ACK: handled in dispatch */
2915 /* if (tcp_ack (th0))
2917 tcp_send_reset (b0, is_ip4);
2921 /* 3. check for a SYN (did that already) */
2923 /* Make sure connection wasn't just created */
2924 child0 = tcp_lookup_connection (lc0->c_fib_index, b0,
2925 my_thread_index, is_ip4);
2926 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
2928 error0 = TCP_ERROR_CREATE_EXISTS;
2932 /* Create child session and send SYN-ACK */
2933 child0 = tcp_connection_new (my_thread_index);
2934 child0->c_lcl_port = th0->dst_port;
2935 child0->c_rmt_port = th0->src_port;
2936 child0->c_is_ip4 = is_ip4;
2937 child0->state = TCP_STATE_SYN_RCVD;
2938 child0->c_fib_index = lc0->c_fib_index;
2942 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
2943 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
2947 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
2948 sizeof (ip6_address_t));
2949 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
2950 sizeof (ip6_address_t));
2953 if (tcp_options_parse (th0, &child0->rcv_opts))
2955 clib_warning ("options parse fail");
2959 child0->irs = vnet_buffer (b0)->tcp.seq_number;
2960 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
2961 child0->rcv_las = child0->rcv_nxt;
2962 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2964 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
2965 * segments are used to initialize PAWS. */
2966 if (tcp_opts_tstamp (&child0->rcv_opts))
2968 child0->tsval_recent = child0->rcv_opts.tsval;
2969 child0->tsval_recent_age = tcp_time_now ();
2972 if (tcp_opts_wscale (&child0->rcv_opts))
2973 child0->snd_wscale = child0->rcv_opts.wscale;
2975 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
2976 << child0->snd_wscale;
2977 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2978 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2980 tcp_connection_init_vars (child0);
2981 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
2983 if (stream_session_accept (&child0->connection, lc0->c_s_index,
2986 clib_warning ("session accept fail");
2987 tcp_connection_cleanup (child0);
2988 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2992 /* Reuse buffer to make syn-ack and send */
2993 tcp_make_synack (child0, b0);
2994 next0 = tcp_next_output (is_ip4);
2995 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
2998 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3000 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3001 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3002 clib_memcpy (&t0->tcp_connection, lc0,
3003 sizeof (t0->tcp_connection));
3006 n_syns += (error0 == TCP_ERROR_NONE);
3007 b0->error = node->errors[error0];
3009 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
3010 n_left_to_next, bi0, next0);
3013 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
3016 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3017 return from_frame->n_vectors;
3021 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3022 vlib_frame_t * from_frame)
3024 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3028 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3029 vlib_frame_t * from_frame)
3031 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3035 VLIB_REGISTER_NODE (tcp4_listen_node) =
3037 .function = tcp4_listen,
3038 .name = "tcp4-listen",
3039 /* Takes a vector of packets. */
3040 .vector_size = sizeof (u32),
3041 .n_errors = TCP_N_ERROR,
3042 .error_strings = tcp_error_strings,
3043 .n_next_nodes = TCP_LISTEN_N_NEXT,
3046 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3047 foreach_tcp_state_next
3050 .format_trace = format_tcp_rx_trace_short,
3054 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
3057 VLIB_REGISTER_NODE (tcp6_listen_node) =
3059 .function = tcp6_listen,
3060 .name = "tcp6-listen",
3061 /* Takes a vector of packets. */
3062 .vector_size = sizeof (u32),
3063 .n_errors = TCP_N_ERROR,
3064 .error_strings = tcp_error_strings,
3065 .n_next_nodes = TCP_LISTEN_N_NEXT,
3068 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3069 foreach_tcp_state_next
3072 .format_trace = format_tcp_rx_trace_short,
3076 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
3078 vlib_node_registration_t tcp4_input_node;
3079 vlib_node_registration_t tcp6_input_node;
3081 typedef enum _tcp_input_next
3083 TCP_INPUT_NEXT_DROP,
3084 TCP_INPUT_NEXT_LISTEN,
3085 TCP_INPUT_NEXT_RCV_PROCESS,
3086 TCP_INPUT_NEXT_SYN_SENT,
3087 TCP_INPUT_NEXT_ESTABLISHED,
3088 TCP_INPUT_NEXT_RESET,
3089 TCP_INPUT_NEXT_PUNT,
3093 #define foreach_tcp4_input_next \
3094 _ (DROP, "ip4-drop") \
3095 _ (LISTEN, "tcp4-listen") \
3096 _ (RCV_PROCESS, "tcp4-rcv-process") \
3097 _ (SYN_SENT, "tcp4-syn-sent") \
3098 _ (ESTABLISHED, "tcp4-established") \
3099 _ (RESET, "tcp4-reset") \
3100 _ (PUNT, "ip4-punt")
3102 #define foreach_tcp6_input_next \
3103 _ (DROP, "ip6-drop") \
3104 _ (LISTEN, "tcp6-listen") \
3105 _ (RCV_PROCESS, "tcp6-rcv-process") \
3106 _ (SYN_SENT, "tcp6-syn-sent") \
3107 _ (ESTABLISHED, "tcp6-established") \
3108 _ (RESET, "tcp6-reset") \
3109 _ (PUNT, "ip6-punt")
3111 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3114 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3115 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3117 tcp_connection_t *tc;
3122 for (i = 0; i < n_bufs; i++)
3124 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3126 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3127 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3129 tcp = vlib_buffer_get_current (bs[i]);
3130 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3136 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3138 if (*error == TCP_ERROR_FILTERED)
3140 *next = TCP_INPUT_NEXT_DROP;
3142 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3144 *next = TCP_INPUT_NEXT_PUNT;
3145 *error = TCP_ERROR_PUNT;
3149 *next = TCP_INPUT_NEXT_RESET;
3150 *error = TCP_ERROR_NO_LISTENER;
3154 static inline tcp_connection_t *
3155 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3158 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3159 int n_advance_bytes, n_data_bytes;
3160 transport_connection_t *tc;
3166 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3167 tcp = ip4_next_header (ip4);
3168 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3169 n_advance_bytes = (ip4_header_bytes (ip4) + tcp_header_bytes (tcp));
3170 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3172 /* Length check. Checksum computed by ipx_local no need to compute again */
3173 if (PREDICT_FALSE (n_advance_bytes < 0))
3175 *error = TCP_ERROR_LENGTH;
3179 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3180 &ip4->src_address, tcp->dst_port,
3181 tcp->src_port, TRANSPORT_PROTO_TCP,
3182 thread_index, &is_filtered);
3186 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3187 tcp = ip6_next_header (ip6);
3188 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3189 n_advance_bytes = tcp_header_bytes (tcp);
3190 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3192 n_advance_bytes += sizeof (ip6[0]);
3194 if (PREDICT_FALSE (n_advance_bytes < 0))
3196 *error = TCP_ERROR_LENGTH;
3200 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3201 &ip6->src_address, tcp->dst_port,
3202 tcp->src_port, TRANSPORT_PROTO_TCP,
3203 thread_index, &is_filtered);
3206 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3207 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3208 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3209 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3210 vnet_buffer (b)->tcp.flags = 0;
3212 *error = is_filtered ? TCP_ERROR_FILTERED : *error;
3214 return tcp_get_connection_from_transport (tc);
3218 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3219 vlib_buffer_t * b, u16 * next, u32 * error)
3224 tcp = tcp_buffer_hdr (b);
3225 flags = tcp->flags & filter_flags;
3226 *next = tm->dispatch_table[tc->state][flags].next;
3227 *error = tm->dispatch_table[tc->state][flags].error;
3229 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3230 || *next == TCP_INPUT_NEXT_RESET))
3232 /* Overload tcp flags to store state */
3233 tcp_state_t state = tc->state;
3234 vnet_buffer (b)->tcp.flags = tc->state;
3236 if (*error == TCP_ERROR_DISPATCH)
3237 clib_warning ("disp error state %U flags %U", format_tcp_state,
3238 state, format_tcp_flags, (int) flags);
3243 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3244 vlib_frame_t * frame, int is_ip4)
3246 u32 n_left_from, *from, thread_index = vm->thread_index;
3247 tcp_main_t *tm = vnet_get_tcp_main ();
3248 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3249 u16 nexts[VLIB_FRAME_SIZE], *next;
3251 tcp_set_time_now (thread_index);
3253 from = vlib_frame_vector_args (frame);
3254 n_left_from = frame->n_vectors;
3255 vlib_get_buffers (vm, from, bufs, n_left_from);
3260 while (n_left_from >= 4)
3262 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3263 tcp_connection_t *tc0, *tc1;
3266 vlib_prefetch_buffer_header (b[2], STORE);
3267 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3269 vlib_prefetch_buffer_header (b[3], STORE);
3270 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3273 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3275 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3276 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4);
3278 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3280 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3281 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3283 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3284 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3286 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3287 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3291 if (PREDICT_TRUE (tc0 != 0))
3293 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3294 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3295 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3298 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3300 if (PREDICT_TRUE (tc1 != 0))
3302 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3303 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3304 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3307 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3314 while (n_left_from > 0)
3316 tcp_connection_t *tc0;
3317 u32 error0 = TCP_ERROR_NO_LISTENER;
3319 if (n_left_from > 1)
3321 vlib_prefetch_buffer_header (b[1], STORE);
3322 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3325 next[0] = TCP_INPUT_NEXT_DROP;
3326 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3327 if (PREDICT_TRUE (tc0 != 0))
3329 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3330 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3331 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3334 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3341 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3342 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3344 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3345 return frame->n_vectors;
3349 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3350 vlib_frame_t * from_frame)
3352 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3356 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3357 vlib_frame_t * from_frame)
3359 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3363 VLIB_REGISTER_NODE (tcp4_input_node) =
3365 .function = tcp4_input,
3366 .name = "tcp4-input",
3367 /* Takes a vector of packets. */
3368 .vector_size = sizeof (u32),
3369 .n_errors = TCP_N_ERROR,
3370 .error_strings = tcp_error_strings,
3371 .n_next_nodes = TCP_INPUT_N_NEXT,
3374 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3375 foreach_tcp4_input_next
3378 .format_buffer = format_tcp_header,
3379 .format_trace = format_tcp_rx_trace,
3383 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3386 VLIB_REGISTER_NODE (tcp6_input_node) =
3388 .function = tcp6_input,
3389 .name = "tcp6-input",
3390 /* Takes a vector of packets. */
3391 .vector_size = sizeof (u32),
3392 .n_errors = TCP_N_ERROR,
3393 .error_strings = tcp_error_strings,
3394 .n_next_nodes = TCP_INPUT_N_NEXT,
3397 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3398 foreach_tcp6_input_next
3401 .format_buffer = format_tcp_header,
3402 .format_trace = format_tcp_rx_trace,
3406 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3409 tcp_dispatch_table_init (tcp_main_t * tm)
3412 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3413 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3415 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3416 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3419 #define _(t,f,n,e) \
3421 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3422 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3425 /* SYNs for new connections -> tcp-listen. */
3426 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3427 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3428 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_RST_RCVD);
3429 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3431 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3432 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3433 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3434 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3435 /* SYN-ACK for a SYN */
3436 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3438 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3439 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3440 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3442 /* ACK for for established connection -> tcp-established. */
3443 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3444 /* FIN for for established connection -> tcp-established. */
3445 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3446 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3448 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3449 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3451 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3452 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3454 /* ACK or FIN-ACK to our FIN */
3455 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3456 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3458 /* FIN in reply to our FIN from the other side */
3459 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3460 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3461 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3462 /* FIN confirming that the peer (app) has closed */
3463 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3464 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3465 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3467 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3468 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3470 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3471 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3472 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3474 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3475 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3476 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3478 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3479 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3480 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3481 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3482 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3483 TCP_ERROR_CONNECTION_CLOSED);
3487 static clib_error_t *
3488 tcp_input_init (vlib_main_t * vm)
3490 clib_error_t *error = 0;
3491 tcp_main_t *tm = vnet_get_tcp_main ();
3493 if ((error = vlib_call_init_function (vm, tcp_init)))
3496 /* Initialize dispatch table. */
3497 tcp_dispatch_table_init (tm);
3502 VLIB_INIT_FUNCTION (tcp_input_init);
3505 * fd.io coding-style-patch-verification: ON
3508 * eval: (c-set-style "gnu")