2 * Copyright (c) 2016 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
16 #include <vppinfra/sparse_vec.h>
17 #include <vnet/tcp/tcp_packet.h>
18 #include <vnet/tcp/tcp.h>
19 #include <vnet/session/session.h>
22 static char *tcp_error_strings[] = {
23 #define tcp_error(n,s) s,
24 #include <vnet/tcp/tcp_error.def>
28 /* All TCP nodes have the same outgoing arcs */
29 #define foreach_tcp_state_next \
30 _ (DROP4, "ip4-drop") \
31 _ (DROP6, "ip6-drop") \
32 _ (TCP4_OUTPUT, "tcp4-output") \
33 _ (TCP6_OUTPUT, "tcp6-output")
35 typedef enum _tcp_established_next
37 #define _(s,n) TCP_ESTABLISHED_NEXT_##s,
38 foreach_tcp_state_next
40 TCP_ESTABLISHED_N_NEXT,
41 } tcp_established_next_t;
43 typedef enum _tcp_rcv_process_next
45 #define _(s,n) TCP_RCV_PROCESS_NEXT_##s,
46 foreach_tcp_state_next
48 TCP_RCV_PROCESS_N_NEXT,
49 } tcp_rcv_process_next_t;
51 typedef enum _tcp_syn_sent_next
53 #define _(s,n) TCP_SYN_SENT_NEXT_##s,
54 foreach_tcp_state_next
57 } tcp_syn_sent_next_t;
59 typedef enum _tcp_listen_next
61 #define _(s,n) TCP_LISTEN_NEXT_##s,
62 foreach_tcp_state_next
67 /* Generic, state independent indices */
68 typedef enum _tcp_state_next
70 #define _(s,n) TCP_NEXT_##s,
71 foreach_tcp_state_next
76 #define tcp_next_output(is_ip4) (is_ip4 ? TCP_NEXT_TCP4_OUTPUT \
77 : TCP_NEXT_TCP6_OUTPUT)
79 #define tcp_next_drop(is_ip4) (is_ip4 ? TCP_NEXT_DROP4 \
82 vlib_node_registration_t tcp4_established_node;
83 vlib_node_registration_t tcp6_established_node;
86 * Validate segment sequence number. As per RFC793:
88 * Segment Receive Test
90 * ------- ------- -------------------------------------------
91 * 0 0 SEG.SEQ = RCV.NXT
92 * 0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
94 * >0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
95 * or RCV.NXT =< SEG.SEQ+SEG.LEN-1 < RCV.NXT+RCV.WND
97 * This ultimately consists in checking if segment falls within the window.
98 * The one important difference compared to RFC793 is that we use rcv_las,
99 * or the rcv_nxt at last ack sent instead of rcv_nxt since that's the
100 * peer's reference when computing our receive window.
103 * seq_leq (end_seq, tc->rcv_las + tc->rcv_wnd) && seq_geq (seq, tc->rcv_las)
104 * however, is too strict when we have retransmits. Instead we just check that
105 * the seq is not beyond the right edge and that the end of the segment is not
106 * less than the left edge.
108 * N.B. rcv_nxt and rcv_wnd are both updated in this node if acks are sent, so
109 * use rcv_nxt in the right edge window test instead of rcv_las.
113 tcp_segment_in_rcv_wnd (tcp_connection_t * tc, u32 seq, u32 end_seq)
115 return (seq_geq (end_seq, tc->rcv_las)
116 && seq_leq (seq, tc->rcv_nxt + tc->rcv_wnd));
120 * Parse TCP header options.
122 * @param th TCP header
123 * @param to TCP options data structure to be populated
124 * @return -1 if parsing failed
127 tcp_options_parse (tcp_header_t * th, tcp_options_t * to)
130 u8 opt_len, opts_len, kind;
134 opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t);
135 data = (const u8 *) (th + 1);
137 /* Zero out all flags but those set in SYN */
138 to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE
139 | TCP_OPTS_FLAG_SACK);
141 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
145 /* Get options length */
146 if (kind == TCP_OPTION_EOL)
148 else if (kind == TCP_OPTION_NOOP)
160 /* weird option length */
161 if (opt_len < 2 || opt_len > opts_len)
169 if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
171 to->flags |= TCP_OPTS_FLAG_MSS;
172 to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
175 case TCP_OPTION_WINDOW_SCALE:
176 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
178 to->flags |= TCP_OPTS_FLAG_WSCALE;
179 to->wscale = data[2];
180 if (to->wscale > TCP_MAX_WND_SCALE)
182 clib_warning ("Illegal window scaling value: %d",
184 to->wscale = TCP_MAX_WND_SCALE;
188 case TCP_OPTION_TIMESTAMP:
189 if (opt_len == TCP_OPTION_LEN_TIMESTAMP)
191 to->flags |= TCP_OPTS_FLAG_TSTAMP;
192 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
193 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
196 case TCP_OPTION_SACK_PERMITTED:
197 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
198 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
200 case TCP_OPTION_SACK_BLOCK:
201 /* If SACK permitted was not advertised or a SYN, break */
202 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
205 /* If too short or not correctly formatted, break */
206 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
209 to->flags |= TCP_OPTS_FLAG_SACK;
210 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
211 vec_reset_length (to->sacks);
212 for (j = 0; j < to->n_sack_blocks; j++)
214 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 8 * j));
215 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 8 * j));
216 vec_add1 (to->sacks, b);
220 /* Nothing to see here */
228 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
229 * timestamp to echo and it's less than tsval_recent, drop segment
230 * but still send an ACK in order to retain TCP's mechanism for detecting
231 * and recovering from half-open connections
233 * Or at least that's what the theory says. It seems that this might not work
234 * very well with packet reordering and fast retransmit. XXX
237 tcp_segment_check_paws (tcp_connection_t * tc)
239 return tcp_opts_tstamp (&tc->rcv_opts) && tc->tsval_recent
240 && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent);
244 * Update tsval recent
247 tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
250 * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
251 * of an incoming segment:
252 * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
253 * then the TSval from the segment is copied to TS.Recent;
254 * otherwise, the TSval is ignored.
256 if (tcp_opts_tstamp (&tc->rcv_opts) && seq_leq (seq, tc->rcv_las)
257 && seq_leq (tc->rcv_las, seq_end))
259 ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval));
260 tc->tsval_recent = tc->rcv_opts.tsval;
261 tc->tsval_recent_age = tcp_time_now_w_thread (tc->c_thread_index);
266 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
268 * It first verifies if segment has a wrapped sequence number (PAWS) and then
269 * does the processing associated to the first four steps (ignoring security
270 * and precedence): sequence number, rst bit and syn bit checks.
272 * @return 0 if segments passes validation.
275 tcp_segment_validate (tcp_worker_ctx_t * wrk, tcp_connection_t * tc0,
276 vlib_buffer_t * b0, tcp_header_t * th0, 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,
310 tcp_time_now_w_thread (tc0->c_thread_index)))
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_program_ack (wrk, tc0);
322 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
328 /* 1st: check sequence number */
329 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
330 vnet_buffer (b0)->tcp.seq_end))
332 *error0 = TCP_ERROR_RCV_WND;
333 /* If our window is 0 and the packet is in sequence, let it pass
334 * through for ack processing. It should be dropped later. */
335 if (!(tc0->rcv_wnd == 0
336 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number))
338 /* If not RST, send dup ack */
341 tcp_program_dupack (wrk, tc0);
342 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp);
348 /* 2nd: check the RST bit */
349 if (PREDICT_FALSE (tcp_rst (th0)))
351 tcp_connection_reset (tc0);
352 *error0 = TCP_ERROR_RST_RCVD;
356 /* 3rd: check security and precedence (skip) */
358 /* 4th: check the SYN bit */
359 if (PREDICT_FALSE (tcp_syn (th0)))
361 /* TODO implement RFC 5961 */
362 if (tc0->state == TCP_STATE_SYN_RCVD)
364 tcp_send_synack (tc0);
365 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0, 0);
369 tcp_program_ack (wrk, tc0);
370 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, tc0);
375 /* If segment in window, save timestamp */
376 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
377 vnet_buffer (b0)->tcp.seq_end);
385 tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0)
387 /* SND.UNA =< SEG.ACK =< SND.NXT */
388 return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number)
389 && seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt));
393 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
395 * Note that although the original article, srtt and rttvar are scaled
396 * to minimize round-off errors, here we don't. Instead, we rely on
397 * better precision time measurements.
399 * TODO support us rtt resolution
402 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
408 err = mrtt - tc->srtt;
410 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
411 * The increase should be bound */
412 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
413 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
414 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
418 /* First measurement. */
420 tc->rttvar = mrtt >> 1;
425 tcp_update_rto (tcp_connection_t * tc)
427 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
428 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
432 * Update RTT estimate and RTO timer
434 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
435 * timing. Middle boxes are known to fiddle with TCP options so we
436 * should give higher priority to ACK timing.
438 * This should be called only if previously sent bytes have been acked.
440 * return 1 if valid rtt 0 otherwise
443 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
447 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
448 * RTT because they're ambiguous. */
449 if (tcp_in_cong_recovery (tc) || tc->sack_sb.sacked_bytes)
451 if (tcp_in_recovery (tc))
456 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
458 tc->mrtt_us = tcp_time_now_us (tc->c_thread_index) - tc->rtt_ts;
459 mrtt = clib_max ((u32) (tc->mrtt_us * THZ), 1);
461 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
462 * snd_una, i.e., the left side of the send window:
463 * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
464 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
466 u32 now = tcp_time_now_w_thread (tc->c_thread_index);
467 mrtt = clib_max (now - tc->rcv_opts.tsecr, 1);
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 mrtt is not valid since we update the rto lower */
490 * Dequeue bytes for connections that have received acks in last burst
493 tcp_handle_postponed_dequeues (tcp_worker_ctx_t * wrk)
495 u32 thread_index = wrk->vm->thread_index;
496 u32 *pending_deq_acked;
497 tcp_connection_t *tc;
500 if (!vec_len (wrk->pending_deq_acked))
503 pending_deq_acked = wrk->pending_deq_acked;
504 for (i = 0; i < vec_len (pending_deq_acked); i++)
506 tc = tcp_connection_get (pending_deq_acked[i], thread_index);
507 tc->flags &= ~TCP_CONN_DEQ_PENDING;
509 /* Dequeue the newly ACKed bytes */
510 stream_session_dequeue_drop (&tc->connection, tc->burst_acked);
512 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
514 /* If everything has been acked, stop retransmit timer
515 * otherwise update. */
516 tcp_retransmit_timer_update (tc);
518 _vec_len (wrk->pending_deq_acked) = 0;
522 tcp_program_dequeue (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
524 if (!(tc->flags & TCP_CONN_DEQ_PENDING))
526 vec_add1 (wrk->pending_deq_acked, tc->c_c_index);
527 tc->flags |= TCP_CONN_DEQ_PENDING;
529 tc->burst_acked += tc->bytes_acked + tc->sack_sb.snd_una_adv;
533 * Check if duplicate ack as per RFC5681 Sec. 2
536 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
539 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
540 && seq_gt (tc->snd_una_max, tc->snd_una)
541 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
542 && (prev_snd_wnd == tc->snd_wnd));
546 * Checks if ack is a congestion control event.
549 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
550 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
552 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
553 * defined to be 'duplicate' */
554 *is_dack = tc->sack_sb.last_sacked_bytes
555 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
557 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
561 scoreboard_hole_index (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
563 ASSERT (!pool_is_free_index (sb->holes, hole - sb->holes));
564 return hole - sb->holes;
568 scoreboard_hole_bytes (sack_scoreboard_hole_t * hole)
570 return hole->end - hole->start;
573 sack_scoreboard_hole_t *
574 scoreboard_get_hole (sack_scoreboard_t * sb, u32 index)
576 if (index != TCP_INVALID_SACK_HOLE_INDEX)
577 return pool_elt_at_index (sb->holes, index);
581 sack_scoreboard_hole_t *
582 scoreboard_next_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
584 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
585 return pool_elt_at_index (sb->holes, hole->next);
589 sack_scoreboard_hole_t *
590 scoreboard_prev_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
592 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
593 return pool_elt_at_index (sb->holes, hole->prev);
597 sack_scoreboard_hole_t *
598 scoreboard_first_hole (sack_scoreboard_t * sb)
600 if (sb->head != TCP_INVALID_SACK_HOLE_INDEX)
601 return pool_elt_at_index (sb->holes, sb->head);
605 sack_scoreboard_hole_t *
606 scoreboard_last_hole (sack_scoreboard_t * sb)
608 if (sb->tail != TCP_INVALID_SACK_HOLE_INDEX)
609 return pool_elt_at_index (sb->holes, sb->tail);
614 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
616 sack_scoreboard_hole_t *next, *prev;
618 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
620 next = pool_elt_at_index (sb->holes, hole->next);
621 next->prev = hole->prev;
625 sb->tail = hole->prev;
628 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
630 prev = pool_elt_at_index (sb->holes, hole->prev);
631 prev->next = hole->next;
635 sb->head = hole->next;
638 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
639 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
641 /* Poison the entry */
643 clib_memset (hole, 0xfe, sizeof (*hole));
645 pool_put (sb->holes, hole);
648 static sack_scoreboard_hole_t *
649 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
652 sack_scoreboard_hole_t *hole, *next, *prev;
655 pool_get (sb->holes, hole);
656 clib_memset (hole, 0, sizeof (*hole));
660 hole_index = scoreboard_hole_index (sb, hole);
662 prev = scoreboard_get_hole (sb, prev_index);
665 hole->prev = prev_index;
666 hole->next = prev->next;
668 if ((next = scoreboard_next_hole (sb, hole)))
669 next->prev = hole_index;
671 sb->tail = hole_index;
673 prev->next = hole_index;
677 sb->head = hole_index;
678 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
679 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
686 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
688 sack_scoreboard_hole_t *left, *right;
689 u32 bytes = 0, blks = 0;
692 sb->sacked_bytes = 0;
693 left = scoreboard_last_hole (sb);
697 if (seq_gt (sb->high_sacked, left->end))
699 bytes = sb->high_sacked - left->end;
703 while ((right = left)
704 && bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
705 && blks < TCP_DUPACK_THRESHOLD
706 /* left not updated if above conditions fail */
707 && (left = scoreboard_prev_hole (sb, right)))
709 bytes += right->start - left->end;
713 /* left is first lost */
718 sb->lost_bytes += scoreboard_hole_bytes (right);
720 left = scoreboard_prev_hole (sb, right);
722 bytes += right->start - left->end;
724 while ((right = left));
727 sb->sacked_bytes = bytes;
731 * Figure out the next hole to retransmit
733 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
735 sack_scoreboard_hole_t *
736 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
737 sack_scoreboard_hole_t * start,
738 u8 have_unsent, u8 * can_rescue, u8 * snd_limited)
740 sack_scoreboard_hole_t *hole = 0;
742 hole = start ? start : scoreboard_first_hole (sb);
743 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
744 hole = scoreboard_next_hole (sb, hole);
746 /* Nothing, return */
749 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
753 /* Rule (1): if higher than rxt, less than high_sacked and lost */
754 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
756 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
760 /* Rule (2): available unsent data */
763 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
766 /* Rule (3): if hole not lost */
767 else if (seq_lt (hole->start, sb->high_sacked))
770 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
772 /* Rule (4): if hole beyond high_sacked */
775 ASSERT (seq_geq (hole->start, sb->high_sacked));
778 /* HighRxt MUST NOT be updated */
783 if (hole && seq_lt (sb->high_rxt, hole->start))
784 sb->high_rxt = hole->start;
790 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 snd_una)
792 sack_scoreboard_hole_t *hole;
793 hole = scoreboard_first_hole (sb);
796 snd_una = seq_gt (snd_una, hole->start) ? snd_una : hole->start;
797 sb->cur_rxt_hole = sb->head;
799 sb->high_rxt = snd_una;
800 sb->rescue_rxt = snd_una - 1;
804 scoreboard_init (sack_scoreboard_t * sb)
806 sb->head = TCP_INVALID_SACK_HOLE_INDEX;
807 sb->tail = TCP_INVALID_SACK_HOLE_INDEX;
808 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
812 scoreboard_clear (sack_scoreboard_t * sb)
814 sack_scoreboard_hole_t *hole;
815 while ((hole = scoreboard_first_hole (sb)))
817 scoreboard_remove_hole (sb, hole);
819 ASSERT (sb->head == sb->tail && sb->head == TCP_INVALID_SACK_HOLE_INDEX);
820 ASSERT (pool_elts (sb->holes) == 0);
821 sb->sacked_bytes = 0;
822 sb->last_sacked_bytes = 0;
823 sb->last_bytes_delivered = 0;
828 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
832 * Test that scoreboard is sane after recovery
834 * Returns 1 if scoreboard is empty or if first hole beyond
838 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
840 sack_scoreboard_hole_t *hole;
841 hole = scoreboard_first_hole (&tc->sack_sb);
842 return (!hole || (seq_geq (hole->start, tc->snd_una)
843 && seq_lt (hole->end, tc->snd_una_max)));
847 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
849 sack_scoreboard_t *sb = &tc->sack_sb;
850 sack_block_t *blk, tmp;
851 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
852 u32 blk_index = 0, old_sacked_bytes, hole_index;
855 sb->last_sacked_bytes = 0;
856 sb->last_bytes_delivered = 0;
859 if (!tcp_opts_sack (&tc->rcv_opts)
860 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
863 old_sacked_bytes = sb->sacked_bytes;
865 /* Remove invalid blocks */
866 blk = tc->rcv_opts.sacks;
867 while (blk < vec_end (tc->rcv_opts.sacks))
869 if (seq_lt (blk->start, blk->end)
870 && seq_gt (blk->start, tc->snd_una)
871 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_una_max))
876 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
879 /* Add block for cumulative ack */
880 if (seq_gt (ack, tc->snd_una))
882 tmp.start = tc->snd_una;
884 vec_add1 (tc->rcv_opts.sacks, tmp);
887 if (vec_len (tc->rcv_opts.sacks) == 0)
890 tcp_scoreboard_trace_add (tc, ack);
892 /* Make sure blocks are ordered */
893 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
894 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
895 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
897 tmp = tc->rcv_opts.sacks[i];
898 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
899 tc->rcv_opts.sacks[j] = tmp;
902 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
904 /* If no holes, insert the first that covers all outstanding bytes */
905 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
906 tc->snd_una, tc->snd_una_max);
907 sb->tail = scoreboard_hole_index (sb, last_hole);
908 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
909 sb->high_sacked = tmp.end;
913 /* If we have holes but snd_una_max is beyond the last hole, update
915 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
916 last_hole = scoreboard_last_hole (sb);
917 if (seq_gt (tc->snd_una_max, last_hole->end))
919 if (seq_geq (last_hole->start, sb->high_sacked))
921 last_hole->end = tc->snd_una_max;
923 /* New hole after high sacked block */
924 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
926 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
930 /* Keep track of max byte sacked for when the last hole
932 if (seq_gt (tmp.end, sb->high_sacked))
933 sb->high_sacked = tmp.end;
936 /* Walk the holes with the SACK blocks */
937 hole = pool_elt_at_index (sb->holes, sb->head);
938 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
940 blk = &tc->rcv_opts.sacks[blk_index];
941 if (seq_leq (blk->start, hole->start))
943 /* Block covers hole. Remove hole */
944 if (seq_geq (blk->end, hole->end))
946 next_hole = scoreboard_next_hole (sb, hole);
948 /* Byte accounting: snd_una needs to be advanced */
953 if (seq_lt (ack, next_hole->start))
954 sb->snd_una_adv = next_hole->start - ack;
955 sb->last_bytes_delivered +=
956 next_hole->start - hole->end;
960 ASSERT (seq_geq (sb->high_sacked, ack));
961 sb->snd_una_adv = sb->high_sacked - ack;
962 sb->last_bytes_delivered += sb->high_sacked - hole->end;
966 scoreboard_remove_hole (sb, hole);
969 /* Partial 'head' overlap */
972 if (seq_gt (blk->end, hole->start))
974 hole->start = blk->end;
981 /* Hole must be split */
982 if (seq_lt (blk->end, hole->end))
984 hole_index = scoreboard_hole_index (sb, hole);
985 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
988 /* Pool might've moved */
989 hole = scoreboard_get_hole (sb, hole_index);
990 hole->end = blk->start;
992 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
994 else if (seq_lt (blk->start, hole->end))
996 hole->end = blk->start;
998 hole = scoreboard_next_hole (sb, hole);
1002 if (pool_elts (sb->holes) == 1)
1004 hole = scoreboard_first_hole (sb);
1005 if (hole->start == ack + sb->snd_una_adv
1006 && hole->end == tc->snd_una_max)
1007 scoreboard_remove_hole (sb, hole);
1010 scoreboard_update_bytes (tc, sb);
1011 sb->last_sacked_bytes = sb->sacked_bytes
1012 - (old_sacked_bytes - sb->last_bytes_delivered);
1013 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
1014 ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
1015 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
1016 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
1017 - seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
1018 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
1019 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
1020 TCP_EVT_DBG (TCP_EVT_CC_SCOREBOARD, tc);
1024 * Try to update snd_wnd based on feedback received from peer.
1026 * If successful, and new window is 'effectively' 0, activate persist
1030 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
1032 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
1033 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
1034 if (seq_lt (tc->snd_wl1, seq)
1035 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
1037 tc->snd_wnd = snd_wnd;
1040 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
1042 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
1044 /* Set persist timer if not set and we just got 0 wnd */
1045 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
1046 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
1047 tcp_persist_timer_set (tc);
1051 tcp_persist_timer_reset (tc);
1052 if (PREDICT_FALSE (!tcp_in_recovery (tc) && tc->rto_boff > 0))
1055 tcp_update_rto (tc);
1062 * Init loss recovery/fast recovery.
1064 * Triggered by dup acks as opposed to timer timeout. Note that cwnd is
1065 * updated in @ref tcp_cc_handle_event after fast retransmit
1068 tcp_cc_init_congestion (tcp_connection_t * tc)
1070 tcp_fastrecovery_on (tc);
1071 tc->snd_congestion = tc->snd_una_max;
1072 tc->cwnd_acc_bytes = 0;
1073 tc->snd_rxt_bytes = 0;
1074 tc->prev_ssthresh = tc->ssthresh;
1075 tc->prev_cwnd = tc->cwnd;
1076 tc->cc_algo->congestion (tc);
1077 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
1081 tcp_cc_recovery_exit (tcp_connection_t * tc)
1084 tcp_update_rto (tc);
1086 tc->snd_nxt = tc->snd_una_max;
1087 tcp_recovery_off (tc);
1088 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1092 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
1094 tc->cc_algo->recovered (tc);
1095 tc->snd_rxt_bytes = 0;
1096 tc->rcv_dupacks = 0;
1097 tc->snd_nxt = tc->snd_una_max;
1098 tc->snd_rxt_bytes = 0;
1100 tcp_fastrecovery_off (tc);
1101 tcp_fastrecovery_1_smss_off (tc);
1102 tcp_fastrecovery_first_off (tc);
1104 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
1108 tcp_cc_congestion_undo (tcp_connection_t * tc)
1110 tc->cwnd = tc->prev_cwnd;
1111 tc->ssthresh = tc->prev_ssthresh;
1112 tc->snd_nxt = tc->snd_una_max;
1113 tc->rcv_dupacks = 0;
1114 if (tcp_in_recovery (tc))
1115 tcp_cc_recovery_exit (tc);
1116 else if (tcp_in_fastrecovery (tc))
1117 tcp_cc_fastrecovery_exit (tc);
1118 ASSERT (tc->rto_boff == 0);
1119 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
1123 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc)
1125 return (tcp_in_recovery (tc) && tc->rto_boff == 1
1127 && tcp_opts_tstamp (&tc->rcv_opts)
1128 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
1132 tcp_cc_is_spurious_fast_rxt (tcp_connection_t * tc)
1134 return (tcp_in_fastrecovery (tc)
1135 && tc->cwnd > tc->ssthresh + 3 * tc->snd_mss);
1139 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
1141 return (tcp_cc_is_spurious_timeout_rxt (tc)
1142 || tcp_cc_is_spurious_fast_rxt (tc));
1146 tcp_cc_recover (tcp_connection_t * tc)
1148 ASSERT (tcp_in_cong_recovery (tc));
1149 if (tcp_cc_is_spurious_retransmit (tc))
1151 tcp_cc_congestion_undo (tc);
1155 if (tcp_in_recovery (tc))
1156 tcp_cc_recovery_exit (tc);
1157 else if (tcp_in_fastrecovery (tc))
1158 tcp_cc_fastrecovery_exit (tc);
1160 ASSERT (tc->rto_boff == 0);
1161 ASSERT (!tcp_in_cong_recovery (tc));
1162 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
1167 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
1169 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
1171 /* Congestion avoidance */
1172 tcp_cc_rcv_ack (tc);
1174 /* If a cumulative ack, make sure dupacks is 0 */
1175 tc->rcv_dupacks = 0;
1177 /* When dupacks hits the threshold we only enter fast retransmit if
1178 * cumulative ack covers more than snd_congestion. Should snd_una
1179 * wrap this test may fail under otherwise valid circumstances.
1180 * Therefore, proactively update snd_congestion when wrap detected. */
1182 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1183 && seq_gt (tc->snd_congestion, tc->snd_una)))
1184 tc->snd_congestion = tc->snd_una - 1;
1188 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1190 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1194 tcp_should_fastrecover (tcp_connection_t * tc)
1196 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1197 || tcp_should_fastrecover_sack (tc));
1201 tcp_program_fastretransmit (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1203 if (!(tc->flags & TCP_CONN_FRXT_PENDING))
1205 vec_add1 (wrk->pending_fast_rxt, tc->c_c_index);
1206 tc->flags |= TCP_CONN_FRXT_PENDING;
1211 tcp_do_fastretransmits (tcp_worker_ctx_t * wrk)
1213 u32 *ongoing_fast_rxt, burst_bytes, sent_bytes, thread_index;
1214 u32 max_burst_size, burst_size, n_segs = 0, n_segs_now;
1215 tcp_connection_t *tc;
1219 if (vec_len (wrk->pending_fast_rxt) == 0
1220 && vec_len (wrk->postponed_fast_rxt) == 0)
1223 thread_index = wrk->vm->thread_index;
1224 last_cpu_time = wrk->vm->clib_time.last_cpu_time;
1225 ongoing_fast_rxt = wrk->ongoing_fast_rxt;
1226 vec_append (ongoing_fast_rxt, wrk->postponed_fast_rxt);
1227 vec_append (ongoing_fast_rxt, wrk->pending_fast_rxt);
1229 _vec_len (wrk->postponed_fast_rxt) = 0;
1230 _vec_len (wrk->pending_fast_rxt) = 0;
1232 max_burst_size = VLIB_FRAME_SIZE / vec_len (ongoing_fast_rxt);
1233 max_burst_size = clib_max (max_burst_size, 1);
1235 for (i = 0; i < vec_len (ongoing_fast_rxt); i++)
1237 if (n_segs >= VLIB_FRAME_SIZE)
1239 vec_add1 (wrk->postponed_fast_rxt, ongoing_fast_rxt[i]);
1243 tc = tcp_connection_get (ongoing_fast_rxt[i], thread_index);
1244 tc->flags &= ~TCP_CONN_FRXT_PENDING;
1246 if (!tcp_in_fastrecovery (tc))
1249 burst_size = clib_min (max_burst_size, VLIB_FRAME_SIZE - n_segs);
1250 burst_bytes = transport_connection_tx_pacer_burst (&tc->connection,
1252 burst_size = clib_min (burst_size, burst_bytes / tc->snd_mss);
1255 tcp_program_fastretransmit (wrk, tc);
1259 n_segs_now = tcp_fast_retransmit (wrk, tc, burst_size);
1260 sent_bytes = clib_min (n_segs_now * tc->snd_mss, burst_bytes);
1261 transport_connection_tx_pacer_update_bytes (&tc->connection,
1263 n_segs += n_segs_now;
1265 _vec_len (ongoing_fast_rxt) = 0;
1266 wrk->ongoing_fast_rxt = ongoing_fast_rxt;
1270 * One function to rule them all ... and in the darkness bind them
1273 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1277 if (tcp_in_fastrecovery (tc) && tcp_opts_sack_permitted (&tc->rcv_opts))
1279 if (tc->bytes_acked)
1281 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1285 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1286 * it account for the bytes that left the network.
1288 else if (is_dack && !tcp_in_recovery (tc))
1290 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1291 ASSERT (tc->snd_una != tc->snd_una_max
1292 || tc->sack_sb.last_sacked_bytes);
1296 /* Pure duplicate ack. If some data got acked, it's handled lower */
1297 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1299 ASSERT (tcp_in_fastrecovery (tc));
1300 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1303 else if (tcp_should_fastrecover (tc))
1307 ASSERT (!tcp_in_fastrecovery (tc));
1309 /* Heuristic to catch potential late dupacks
1310 * after fast retransmit exits */
1311 if (is_dack && tc->snd_una == tc->snd_congestion
1312 && timestamp_leq (tc->rcv_opts.tsecr, tc->tsecr_last_ack))
1314 tc->rcv_dupacks = 0;
1318 tcp_cc_init_congestion (tc);
1319 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1321 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1323 tc->cwnd = tc->ssthresh;
1324 scoreboard_init_high_rxt (&tc->sack_sb, tc->snd_una);
1328 /* Post retransmit update cwnd to ssthresh and account for the
1329 * three segments that have left the network and should've been
1330 * buffered at the receiver XXX */
1331 tc->cwnd = tc->ssthresh + 3 * tc->snd_mss;
1334 /* Constrain rate until we get a partial ack */
1335 pacer_wnd = clib_max (0.1 * tc->cwnd, 2 * tc->snd_mss);
1336 tcp_connection_tx_pacer_reset (tc, pacer_wnd,
1337 0 /* start bucket */ );
1338 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index),
1342 else if (!tc->bytes_acked
1343 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1345 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1351 /* Don't allow entry in fast recovery if still in recovery, for now */
1352 else if (0 && is_dack && tcp_in_recovery (tc))
1354 /* If of of the two conditions lower hold, reset dupacks because
1355 * we're probably after timeout (RFC6582 heuristics).
1356 * If Cumulative ack does not cover more than congestion threshold,
1358 * 1) The following doesn't hold: The congestion window is greater
1359 * than SMSS bytes and the difference between highest_ack
1360 * and prev_highest_ack is at most 4*SMSS bytes
1361 * 2) Echoed timestamp in the last non-dup ack does not equal the
1364 if (seq_leq (tc->snd_una, tc->snd_congestion)
1365 && ((!(tc->cwnd > tc->snd_mss
1366 && tc->bytes_acked <= 4 * tc->snd_mss))
1367 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1369 tc->rcv_dupacks = 0;
1374 if (!tc->bytes_acked)
1378 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1381 * Legitimate ACK. 1) See if we can exit recovery
1384 if (seq_geq (tc->snd_una, tc->snd_congestion))
1386 tcp_retransmit_timer_update (tc);
1388 /* If spurious return, we've already updated everything */
1389 if (tcp_cc_recover (tc))
1391 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1395 tc->snd_nxt = tc->snd_una_max;
1397 /* Treat as congestion avoidance ack */
1398 tcp_cc_rcv_ack (tc);
1403 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1406 /* Update the pacing rate. For the first partial ack we move from
1407 * the artificially constrained rate to the one after congestion */
1408 tcp_connection_tx_pacer_update (tc);
1410 /* XXX limit this only to first partial ack? */
1411 tcp_retransmit_timer_force_update (tc);
1413 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1414 * reset dupacks to 0. Also needed if in congestion recovery */
1415 tc->rcv_dupacks = 0;
1417 /* Post RTO timeout don't try anything fancy */
1418 if (tcp_in_recovery (tc))
1420 tcp_cc_rcv_ack (tc);
1421 transport_add_tx_event (&tc->connection);
1425 /* Remove retransmitted bytes that have been delivered */
1426 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1428 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1429 >= tc->sack_sb.last_bytes_delivered
1430 || (tc->flags & TCP_CONN_FINSNT));
1432 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1433 * remove sacked bytes delivered */
1434 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1436 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1437 - tc->sack_sb.last_bytes_delivered;
1438 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1439 tc->snd_rxt_bytes -= rxt_delivered;
1443 /* Apparently all retransmitted holes have been acked */
1444 tc->snd_rxt_bytes = 0;
1445 tc->sack_sb.high_rxt = tc->snd_una;
1450 tcp_fastrecovery_first_on (tc);
1451 /* Reuse last bytes delivered to track total bytes acked */
1452 tc->sack_sb.last_bytes_delivered += tc->bytes_acked;
1453 if (tc->snd_rxt_bytes > tc->bytes_acked)
1454 tc->snd_rxt_bytes -= tc->bytes_acked;
1456 tc->snd_rxt_bytes = 0;
1459 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1462 * Since this was a partial ack, try to retransmit some more data
1464 tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc);
1468 * Process incoming ACK
1471 tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
1472 tcp_header_t * th, u32 * error)
1474 u32 prev_snd_wnd, prev_snd_una;
1477 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1479 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1480 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1482 /* When we entered recovery, we reset snd_nxt to snd_una. Seems peer
1483 * still has the data so accept the ack */
1484 if (tcp_in_recovery (tc)
1485 && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_congestion))
1487 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1488 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
1489 tc->snd_una_max = tc->snd_nxt;
1493 /* If we have outstanding data and this is within the window, accept it,
1494 * probably retransmit has timed out. Otherwise ACK segment and then
1496 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1498 tcp_program_ack (wrk, tc);
1499 *error = TCP_ERROR_ACK_FUTURE;
1500 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1501 vnet_buffer (b)->tcp.ack_number);
1505 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1506 vnet_buffer (b)->tcp.ack_number);
1508 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1511 /* If old ACK, probably it's an old dupack */
1512 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1514 *error = TCP_ERROR_ACK_OLD;
1515 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1516 vnet_buffer (b)->tcp.ack_number);
1517 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1518 tcp_cc_handle_event (tc, 1);
1519 /* Don't drop yet */
1524 * Looks okay, process feedback
1527 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1528 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1530 prev_snd_wnd = tc->snd_wnd;
1531 prev_snd_una = tc->snd_una;
1532 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1533 vnet_buffer (b)->tcp.ack_number,
1534 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1535 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1536 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1537 tcp_validate_txf_size (tc, tc->bytes_acked);
1539 if (tc->bytes_acked)
1541 tcp_program_dequeue (wrk, tc);
1542 tcp_update_rtt (tc, vnet_buffer (b)->tcp.ack_number);
1545 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1548 * Check if we have congestion event
1551 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1553 tcp_cc_handle_event (tc, is_dack);
1554 if (!tcp_in_cong_recovery (tc))
1556 *error = TCP_ERROR_ACK_DUP;
1557 if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th))
1563 * Update congestion control (slow start/congestion avoidance)
1565 tcp_cc_update (tc, b);
1566 *error = TCP_ERROR_ACK_OK;
1571 tcp_sack_vector_is_sane (sack_block_t * sacks)
1574 for (i = 1; i < vec_len (sacks); i++)
1576 if (sacks[i - 1].end == sacks[i].start)
1583 * Build SACK list as per RFC2018.
1585 * Makes sure the first block contains the segment that generated the current
1586 * ACK and the following ones are the ones most recently reported in SACK
1589 * @param tc TCP connection for which the SACK list is updated
1590 * @param start Start sequence number of the newest SACK block
1591 * @param end End sequence of the newest SACK block
1594 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1596 sack_block_t *new_list = 0, *block = 0;
1599 /* If the first segment is ooo add it to the list. Last write might've moved
1600 * rcv_nxt over the first segment. */
1601 if (seq_lt (tc->rcv_nxt, start))
1603 vec_add2 (new_list, block, 1);
1604 block->start = start;
1608 /* Find the blocks still worth keeping. */
1609 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1611 /* Discard if rcv_nxt advanced beyond current block */
1612 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1615 /* Merge or drop if segment overlapped by the new segment */
1616 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1617 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1619 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1620 new_list[0].start = tc->snd_sacks[i].start;
1621 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1622 new_list[0].end = tc->snd_sacks[i].end;
1626 /* Save to new SACK list if we have space. */
1627 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1629 vec_add1 (new_list, tc->snd_sacks[i]);
1633 clib_warning ("sack discarded");
1637 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1639 /* Replace old vector with new one */
1640 vec_free (tc->snd_sacks);
1641 tc->snd_sacks = new_list;
1643 /* Segments should not 'touch' */
1644 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1648 tcp_sack_list_bytes (tcp_connection_t * tc)
1651 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1652 bytes += tc->snd_sacks[i].end - tc->snd_sacks[i].start;
1656 /** Enqueue data for delivery to application */
1658 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1661 int written, error = TCP_ERROR_ENQUEUED;
1663 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1665 written = session_enqueue_stream_connection (&tc->connection, b, 0,
1666 1 /* queue event */ , 1);
1668 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1670 /* Update rcv_nxt */
1671 if (PREDICT_TRUE (written == data_len))
1673 tc->rcv_nxt += written;
1675 /* If more data written than expected, account for out-of-order bytes. */
1676 else if (written > data_len)
1678 tc->rcv_nxt += written;
1679 TCP_EVT_DBG (TCP_EVT_CC_INPUT, tc, data_len, written);
1681 else if (written > 0)
1683 /* We've written something but FIFO is probably full now */
1684 tc->rcv_nxt += written;
1685 error = TCP_ERROR_PARTIALLY_ENQUEUED;
1689 return TCP_ERROR_FIFO_FULL;
1692 /* Update SACK list if need be */
1693 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1695 /* Remove SACK blocks that have been delivered */
1696 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1702 /** Enqueue out-of-order data */
1704 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1707 stream_session_t *s0;
1710 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1713 /* Enqueue out-of-order data with relative offset */
1714 rv = session_enqueue_stream_connection (&tc->connection, b,
1715 vnet_buffer (b)->tcp.seq_number -
1716 tc->rcv_nxt, 0 /* queue event */ ,
1719 /* Nothing written */
1722 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1723 return TCP_ERROR_FIFO_FULL;
1726 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1728 /* Update SACK list if in use */
1729 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1731 ooo_segment_t *newest;
1734 s0 = session_get (tc->c_s_index, tc->c_thread_index);
1736 /* Get the newest segment from the fifo */
1737 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1740 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1741 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1742 start = tc->rcv_nxt + offset;
1743 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1744 tcp_update_sack_list (tc, start, end);
1745 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1746 TCP_EVT_DBG (TCP_EVT_CC_SACKS, tc);
1750 return TCP_ERROR_ENQUEUED_OOO;
1754 * Check if ACK could be delayed. If ack can be delayed, it should return
1755 * true for a full frame. If we're always acking return 0.
1758 tcp_can_delack (tcp_connection_t * tc)
1760 /* Send ack if ... */
1762 /* just sent a rcv wnd 0 */
1763 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1764 /* constrained to send ack */
1765 || (tc->flags & TCP_CONN_SNDACK) != 0
1766 /* we're almost out of tx wnd */
1767 || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss)
1774 tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
1776 u32 discard, first = b->current_length;
1777 vlib_main_t *vm = vlib_get_main ();
1779 /* Handle multi-buffer segments */
1780 if (n_bytes_to_drop > b->current_length)
1782 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
1786 discard = clib_min (n_bytes_to_drop, b->current_length);
1787 vlib_buffer_advance (b, discard);
1788 b = vlib_get_buffer (vm, b->next_buffer);
1789 n_bytes_to_drop -= discard;
1791 while (n_bytes_to_drop);
1792 if (n_bytes_to_drop > first)
1793 b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
1796 vlib_buffer_advance (b, n_bytes_to_drop);
1797 vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
1802 * Receive buffer for connection and handle acks
1804 * It handles both in order or out-of-order data.
1807 tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1810 u32 error, n_bytes_to_drop, n_data_bytes;
1812 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1813 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1814 ASSERT (n_data_bytes);
1816 /* Handle out-of-order data */
1817 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1819 /* Old sequence numbers allowed through because they overlapped
1821 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1823 /* Completely in the past (possible retransmit). Ack
1824 * retransmissions since we may not have any data to send */
1825 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1827 tcp_program_ack (wrk, tc);
1828 error = TCP_ERROR_SEGMENT_OLD;
1832 /* Chop off the bytes in the past and see if what is left
1833 * can be enqueued in order */
1834 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1835 n_data_bytes -= n_bytes_to_drop;
1836 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1837 if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
1839 error = TCP_ERROR_SEGMENT_OLD;
1845 /* RFC2581: Enqueue and send DUPACK for fast retransmit */
1846 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1847 tcp_program_dupack (wrk, tc);
1848 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp);
1854 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1855 * segments can be enqueued after fifo tail offset changes. */
1856 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1857 if (tcp_can_delack (tc))
1859 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1860 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1864 tcp_program_ack (wrk, tc);
1872 tcp_header_t tcp_header;
1873 tcp_connection_t tcp_connection;
1877 format_tcp_rx_trace (u8 * s, va_list * args)
1879 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1880 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1881 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1882 u32 indent = format_get_indent (s);
1884 s = format (s, "%U\n%U%U",
1885 format_tcp_header, &t->tcp_header, 128,
1886 format_white_space, indent,
1887 format_tcp_connection, &t->tcp_connection, 1);
1893 format_tcp_rx_trace_short (u8 * s, va_list * args)
1895 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1896 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1897 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1899 s = format (s, "%d -> %d (%U)",
1900 clib_net_to_host_u16 (t->tcp_header.dst_port),
1901 clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state,
1902 t->tcp_connection.state);
1908 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1909 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1913 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1917 th0 = tcp_buffer_hdr (b0);
1919 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1923 tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
1924 vlib_frame_t * frame, u8 is_ip4)
1928 n_left = frame->n_vectors;
1929 from = vlib_frame_vector_args (frame);
1933 tcp_connection_t *tc0;
1940 b0 = vlib_get_buffer (vm, bi0);
1942 if (b0->flags & VLIB_BUFFER_IS_TRACED)
1944 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1945 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1947 th0 = tcp_buffer_hdr (b0);
1948 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1957 tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node,
1958 u8 is_ip4, u32 evt, u32 val)
1961 vlib_node_increment_counter (vm, tcp4_node, evt, val);
1963 vlib_node_increment_counter (vm, tcp6_node, evt, val);
1966 #define tcp_maybe_inc_counter(node_id, err, count) \
1968 if (next0 != tcp_next_drop (is_ip4)) \
1969 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1970 tcp6_##node_id##_node.index, is_ip4, err, \
1973 #define tcp_inc_counter(node_id, err, count) \
1974 tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \
1975 tcp6_##node_id##_node.index, is_ip4, \
1977 #define tcp_maybe_inc_err_counter(cnts, err) \
1979 cnts[err] += (next0 != tcp_next_drop (is_ip4)); \
1981 #define tcp_inc_err_counter(cnts, err, val) \
1985 #define tcp_store_err_counters(node_id, cnts) \
1988 for (i = 0; i < TCP_N_ERROR; i++) \
1990 tcp_inc_counter(node_id, i, cnts[i]); \
1995 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1996 vlib_frame_t * frame, int is_ip4)
1998 u32 thread_index = vm->thread_index, errors = 0;
1999 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2000 u32 n_left_from, *from, *first_buffer;
2001 u16 err_counters[TCP_N_ERROR] = { 0 };
2004 if (node->flags & VLIB_NODE_FLAG_TRACE)
2005 tcp_established_trace_frame (vm, node, frame, is_ip4);
2007 first_buffer = from = vlib_frame_vector_args (frame);
2008 n_left_from = frame->n_vectors;
2010 while (n_left_from > 0)
2012 u32 bi0, error0 = TCP_ERROR_ACK_OK;
2014 tcp_header_t *th0 = 0;
2015 tcp_connection_t *tc0;
2017 if (n_left_from > 1)
2020 pb = vlib_get_buffer (vm, from[1]);
2021 vlib_prefetch_buffer_header (pb, LOAD);
2022 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
2029 b0 = vlib_get_buffer (vm, bi0);
2030 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2033 if (PREDICT_FALSE (tc0 == 0))
2035 error0 = TCP_ERROR_INVALID_CONNECTION;
2039 th0 = tcp_buffer_hdr (b0);
2040 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
2041 * dangling reference. */
2042 is_fin = tcp_is_fin (th0);
2044 /* SYNs, FINs and data consume sequence numbers */
2045 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2046 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
2048 /* TODO header prediction fast path */
2050 /* 1-4: check SEQ, RST, SYN */
2051 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0)))
2053 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp);
2057 /* 5: check the ACK field */
2058 if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0)))
2061 /* 6: check the URG bit TODO */
2063 /* 7: process the segment text */
2064 if (vnet_buffer (b0)->tcp.data_len)
2065 error0 = tcp_segment_rcv (wrk, tc0, b0);
2067 /* 8: check the FIN bit */
2068 if (PREDICT_FALSE (is_fin))
2070 /* Enter CLOSE-WAIT and notify session. To avoid lingering
2071 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
2072 /* Account for the FIN if nothing else was received */
2073 if (vnet_buffer (b0)->tcp.data_len == 0)
2075 tcp_program_ack (wrk, tc0);
2076 tc0->state = TCP_STATE_CLOSE_WAIT;
2077 stream_session_disconnect_notify (&tc0->connection);
2078 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
2079 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2080 error0 = TCP_ERROR_FIN_RCVD;
2084 tcp_inc_err_counter (err_counters, error0, 1);
2087 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2089 err_counters[TCP_ERROR_EVENT_FIFO_FULL] = errors;
2090 tcp_store_err_counters (established, err_counters);
2091 tcp_handle_postponed_dequeues (wrk);
2092 vlib_buffer_free (vm, first_buffer, frame->n_vectors);
2094 return frame->n_vectors;
2098 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2099 vlib_frame_t * from_frame)
2101 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2105 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
2106 vlib_frame_t * from_frame)
2108 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2112 VLIB_REGISTER_NODE (tcp4_established_node) =
2114 .function = tcp4_established,
2115 .name = "tcp4-established",
2116 /* Takes a vector of packets. */
2117 .vector_size = sizeof (u32),
2118 .n_errors = TCP_N_ERROR,
2119 .error_strings = tcp_error_strings,
2120 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2123 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2124 foreach_tcp_state_next
2127 .format_trace = format_tcp_rx_trace_short,
2131 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
2134 VLIB_REGISTER_NODE (tcp6_established_node) =
2136 .function = tcp6_established,
2137 .name = "tcp6-established",
2138 /* Takes a vector of packets. */
2139 .vector_size = sizeof (u32),
2140 .n_errors = TCP_N_ERROR,
2141 .error_strings = tcp_error_strings,
2142 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
2145 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
2146 foreach_tcp_state_next
2149 .format_trace = format_tcp_rx_trace_short,
2154 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
2156 vlib_node_registration_t tcp4_syn_sent_node;
2157 vlib_node_registration_t tcp6_syn_sent_node;
2160 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2162 transport_connection_t *tmp = 0;
2169 if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN)
2172 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2173 && (tc->state == TCP_STATE_LISTEN
2174 || tc->c_rmt_port == hdr->src_port));
2178 handle = session_lookup_half_open_handle (&tc->connection);
2179 tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF,
2180 tc->c_proto, tc->c_is_ip4);
2184 if (tmp->lcl_port == hdr->dst_port
2185 && tmp->rmt_port == hdr->src_port)
2187 TCP_DBG ("half-open is valid!");
2195 * Lookup transport connection
2197 static tcp_connection_t *
2198 tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index,
2202 transport_connection_t *tconn;
2203 tcp_connection_t *tc;
2208 ip4 = vlib_buffer_get_current (b);
2209 tcp = ip4_next_header (ip4);
2210 tconn = session_lookup_connection_wt4 (fib_index,
2215 TRANSPORT_PROTO_TCP,
2216 thread_index, &is_filtered);
2217 tc = tcp_get_connection_from_transport (tconn);
2218 ASSERT (tcp_lookup_is_valid (tc, tcp));
2223 ip6 = vlib_buffer_get_current (b);
2224 tcp = ip6_next_header (ip6);
2225 tconn = session_lookup_connection_wt6 (fib_index,
2230 TRANSPORT_PROTO_TCP,
2231 thread_index, &is_filtered);
2232 tc = tcp_get_connection_from_transport (tconn);
2233 ASSERT (tcp_lookup_is_valid (tc, tcp));
2239 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2240 vlib_frame_t * from_frame, int is_ip4)
2242 tcp_main_t *tm = vnet_get_tcp_main ();
2243 u32 n_left_from, *from, *first_buffer, errors = 0;
2244 u32 my_thread_index = vm->thread_index;
2245 tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index);
2247 from = first_buffer = vlib_frame_vector_args (from_frame);
2248 n_left_from = from_frame->n_vectors;
2250 while (n_left_from > 0)
2252 u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE;
2253 tcp_connection_t *tc0, *new_tc0;
2254 tcp_header_t *tcp0 = 0;
2262 b0 = vlib_get_buffer (vm, bi0);
2264 tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index);
2265 if (PREDICT_FALSE (tc0 == 0))
2267 error0 = TCP_ERROR_INVALID_CONNECTION;
2271 /* Half-open completed recently but the connection was't removed
2272 * yet by the owning thread */
2273 if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
2275 /* Make sure the connection actually exists */
2276 ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0,
2277 my_thread_index, is_ip4));
2281 ack0 = vnet_buffer (b0)->tcp.ack_number;
2282 seq0 = vnet_buffer (b0)->tcp.seq_number;
2283 tcp0 = tcp_buffer_hdr (b0);
2285 /* Crude check to see if the connection handle does not match
2286 * the packet. Probably connection just switched to established */
2287 if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
2288 || tcp0->src_port != tc0->c_rmt_port))
2290 error0 = TCP_ERROR_INVALID_CONNECTION;
2294 if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0)
2295 && !tcp_syn (tcp0)))
2297 error0 = TCP_ERROR_SEGMENT_INVALID;
2301 /* SYNs, FINs and data consume sequence numbers */
2302 vnet_buffer (b0)->tcp.seq_end =
2303 seq0 + tcp_is_syn (tcp0) + tcp_is_fin (tcp0) +
2304 vnet_buffer (b0)->tcp.data_len;
2307 * 1. check the ACK bit
2311 * If the ACK bit is set
2312 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
2313 * the RST bit is set, if so drop the segment and return)
2314 * <SEQ=SEG.ACK><CTL=RST>
2315 * and discard the segment. Return.
2316 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
2320 if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
2322 if (!tcp_rst (tcp0))
2323 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2324 error0 = TCP_ERROR_RCV_WND;
2328 /* Make sure ACK is valid */
2329 if (seq_gt (tc0->snd_una, ack0))
2331 error0 = TCP_ERROR_ACK_INVALID;
2337 * 2. check the RST bit
2342 /* If ACK is acceptable, signal client that peer is not
2343 * willing to accept connection and drop connection*/
2345 tcp_connection_reset (tc0);
2346 error0 = TCP_ERROR_RST_RCVD;
2351 * 3. check the security and precedence (skipped)
2355 * 4. check the SYN bit
2358 /* No SYN flag. Drop. */
2359 if (!tcp_syn (tcp0))
2361 clib_warning ("not synack");
2362 error0 = TCP_ERROR_SEGMENT_INVALID;
2367 if (tcp_options_parse (tcp0, &tc0->rcv_opts))
2369 clib_warning ("options parse fail");
2370 error0 = TCP_ERROR_OPTIONS;
2374 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
2375 * current thread pool. */
2376 pool_get (tm->connections[my_thread_index], new_tc0);
2377 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
2378 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
2379 new_tc0->c_thread_index = my_thread_index;
2380 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
2381 new_tc0->irs = seq0;
2382 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
2383 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
2384 new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
2386 /* If this is not the owning thread, wait for syn retransmit to
2387 * expire and cleanup then */
2388 if (tcp_half_open_connection_cleanup (tc0))
2389 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
2391 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
2393 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
2394 new_tc0->tsval_recent_age = tcp_time_now ();
2397 if (tcp_opts_wscale (&new_tc0->rcv_opts))
2398 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
2400 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2401 << new_tc0->snd_wscale;
2402 new_tc0->snd_wl1 = seq0;
2403 new_tc0->snd_wl2 = ack0;
2405 tcp_connection_init_vars (new_tc0);
2407 /* SYN-ACK: See if we can switch to ESTABLISHED state */
2408 if (PREDICT_TRUE (tcp_ack (tcp0)))
2410 /* Our SYN is ACKed: we have iss < ack = snd_una */
2412 /* TODO Dequeue acknowledged segments if we support Fast Open */
2413 new_tc0->snd_una = ack0;
2414 new_tc0->state = TCP_STATE_ESTABLISHED;
2416 /* Make sure las is initialized for the wnd computation */
2417 new_tc0->rcv_las = new_tc0->rcv_nxt;
2419 /* Notify app that we have connection. If session layer can't
2420 * allocate session send reset */
2421 if (session_stream_connect_notify (&new_tc0->connection, 0))
2423 clib_warning ("connect notify fail");
2424 tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
2425 tcp_connection_cleanup (new_tc0);
2429 /* Update rtt with the syn-ack sample */
2430 tcp_update_rtt (new_tc0, vnet_buffer (b0)->tcp.ack_number);
2431 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2432 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2434 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2437 new_tc0->state = TCP_STATE_SYN_RCVD;
2439 /* Notify app that we have connection */
2440 if (session_stream_connect_notify (&new_tc0->connection, 0))
2442 tcp_connection_cleanup (new_tc0);
2443 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2444 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2449 tcp_init_snd_vars (tc0);
2450 tcp_send_synack (new_tc0);
2451 error0 = TCP_ERROR_SYNS_RCVD;
2455 /* Read data, if any */
2456 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2458 clib_warning ("rcvd data in syn-sent");
2459 error0 = tcp_segment_rcv (wrk, new_tc0, b0);
2460 if (error0 == TCP_ERROR_ACK_OK)
2461 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2465 tcp_program_ack (wrk, new_tc0);
2470 tcp_inc_counter (syn_sent, error0, 1);
2471 if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
2473 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2474 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2475 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
2479 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2481 tcp_inc_counter (syn_sent, TCP_ERROR_EVENT_FIFO_FULL, errors);
2482 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2484 return from_frame->n_vectors;
2488 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2489 vlib_frame_t * from_frame)
2491 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2495 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2496 vlib_frame_t * from_frame)
2498 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2502 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2504 .function = tcp4_syn_sent,
2505 .name = "tcp4-syn-sent",
2506 /* Takes a vector of packets. */
2507 .vector_size = sizeof (u32),
2508 .n_errors = TCP_N_ERROR,
2509 .error_strings = tcp_error_strings,
2510 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2513 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2514 foreach_tcp_state_next
2517 .format_trace = format_tcp_rx_trace_short,
2521 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2524 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2526 .function = tcp6_syn_sent_rcv,
2527 .name = "tcp6-syn-sent",
2528 /* Takes a vector of packets. */
2529 .vector_size = sizeof (u32),
2530 .n_errors = TCP_N_ERROR,
2531 .error_strings = tcp_error_strings,
2532 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2535 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2536 foreach_tcp_state_next
2539 .format_trace = format_tcp_rx_trace_short,
2543 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2545 vlib_node_registration_t tcp4_rcv_process_node;
2546 vlib_node_registration_t tcp6_rcv_process_node;
2549 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2550 * as per RFC793 p. 64
2553 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2554 vlib_frame_t * from_frame, int is_ip4)
2556 u32 thread_index = vm->thread_index, errors = 0, *first_buffer;
2557 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
2558 u32 n_left_from, *from;
2560 from = first_buffer = vlib_frame_vector_args (from_frame);
2561 n_left_from = from_frame->n_vectors;
2563 while (n_left_from > 0)
2565 u32 bi0, error0 = TCP_ERROR_NONE;
2566 tcp_header_t *tcp0 = 0;
2567 tcp_connection_t *tc0;
2575 b0 = vlib_get_buffer (vm, bi0);
2576 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2578 if (PREDICT_FALSE (tc0 == 0))
2580 error0 = TCP_ERROR_INVALID_CONNECTION;
2584 tcp0 = tcp_buffer_hdr (b0);
2585 is_fin0 = tcp_is_fin (tcp0);
2587 /* SYNs, FINs and data consume sequence numbers */
2588 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2589 + tcp_is_syn (tcp0) + is_fin0 + vnet_buffer (b0)->tcp.data_len;
2593 tcp_connection_t *tmp;
2594 tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index,
2596 if (tmp->state != tc0->state)
2598 clib_warning ("state changed");
2604 * Special treatment for CLOSED
2606 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
2608 error0 = TCP_ERROR_CONNECTION_CLOSED;
2613 * For all other states (except LISTEN)
2616 /* 1-4: check SEQ, RST, SYN */
2617 if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0)))
2620 /* 5: check the ACK field */
2623 case TCP_STATE_SYN_RCVD:
2625 * If the segment acknowledgment is not acceptable, form a
2627 * <SEQ=SEG.ACK><CTL=RST>
2630 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2632 TCP_DBG ("connection not accepted");
2633 tcp_send_reset_w_pkt (tc0, b0, is_ip4);
2634 error0 = TCP_ERROR_ACK_INVALID;
2638 /* Update rtt and rto */
2639 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
2641 /* Switch state to ESTABLISHED */
2642 tc0->state = TCP_STATE_ESTABLISHED;
2643 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2645 /* Initialize session variables */
2646 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2647 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2648 << tc0->rcv_opts.wscale;
2649 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2650 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2652 /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
2653 tcp_retransmit_timer_reset (tc0);
2654 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
2655 stream_session_accept_notify (&tc0->connection);
2656 error0 = TCP_ERROR_ACK_OK;
2658 case TCP_STATE_ESTABLISHED:
2659 /* We can get packets in established state here because they
2660 * were enqueued before state change */
2661 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2665 case TCP_STATE_FIN_WAIT_1:
2666 /* In addition to the processing for the ESTABLISHED state, if
2667 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2668 * continue processing in that state. */
2669 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2672 /* Still have to send the FIN */
2673 if (tc0->flags & TCP_CONN_FINPNDG)
2675 /* TX fifo finally drained */
2676 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2679 /* If FIN is ACKed */
2680 else if (tc0->snd_una == tc0->snd_una_max)
2682 tc0->state = TCP_STATE_FIN_WAIT_2;
2683 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2685 /* Stop all retransmit timers because we have nothing more
2686 * to send. Enable waitclose though because we're willing to
2687 * wait for peer's FIN but not indefinitely. */
2688 tcp_connection_timers_reset (tc0);
2689 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2692 case TCP_STATE_FIN_WAIT_2:
2693 /* In addition to the processing for the ESTABLISHED state, if
2694 * the retransmission queue is empty, the user's CLOSE can be
2695 * acknowledged ("ok") but do not delete the TCB. */
2696 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2699 case TCP_STATE_CLOSE_WAIT:
2700 /* Do the same processing as for the ESTABLISHED state. */
2701 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2704 if (tc0->flags & TCP_CONN_FINPNDG)
2706 /* TX fifo finally drained */
2707 if (!session_tx_fifo_max_dequeue (&tc0->connection))
2710 tcp_connection_timers_reset (tc0);
2711 tc0->state = TCP_STATE_LAST_ACK;
2712 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2716 case TCP_STATE_CLOSING:
2717 /* In addition to the processing for the ESTABLISHED state, if
2718 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2719 * otherwise ignore the segment. */
2720 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2723 tc0->state = TCP_STATE_TIME_WAIT;
2724 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2725 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2729 case TCP_STATE_LAST_ACK:
2730 /* The only thing that [should] arrive in this state is an
2731 * acknowledgment of our FIN. If our FIN is now acknowledged,
2732 * delete the TCB, enter the CLOSED state, and return. */
2734 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2736 error0 = TCP_ERROR_ACK_INVALID;
2739 error0 = TCP_ERROR_ACK_OK;
2740 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2741 /* Apparently our ACK for the peer's FIN was lost */
2742 if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
2748 tc0->state = TCP_STATE_CLOSED;
2749 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2751 /* Don't free the connection from the data path since
2752 * we can't ensure that we have no packets already enqueued
2753 * to output. Rely instead on the waitclose timer */
2754 tcp_connection_timers_reset (tc0);
2755 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, 1);
2760 case TCP_STATE_TIME_WAIT:
2761 /* The only thing that can arrive in this state is a
2762 * retransmission of the remote FIN. Acknowledge it, and restart
2763 * the 2 MSL timeout. */
2765 if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
2768 tcp_program_ack (wrk, tc0);
2769 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2777 /* 6: check the URG bit TODO */
2779 /* 7: process the segment text */
2782 case TCP_STATE_ESTABLISHED:
2783 case TCP_STATE_FIN_WAIT_1:
2784 case TCP_STATE_FIN_WAIT_2:
2785 if (vnet_buffer (b0)->tcp.data_len)
2786 error0 = tcp_segment_rcv (wrk, tc0, b0);
2790 case TCP_STATE_CLOSE_WAIT:
2791 case TCP_STATE_CLOSING:
2792 case TCP_STATE_LAST_ACK:
2793 case TCP_STATE_TIME_WAIT:
2794 /* This should not occur, since a FIN has been received from the
2795 * remote side. Ignore the segment text. */
2799 /* 8: check the FIN bit */
2805 case TCP_STATE_ESTABLISHED:
2806 case TCP_STATE_SYN_RCVD:
2807 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2808 tcp_connection_timers_reset (tc0);
2810 stream_session_disconnect_notify (&tc0->connection);
2811 tc0->state = TCP_STATE_CLOSE_WAIT;
2812 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2814 case TCP_STATE_CLOSE_WAIT:
2815 case TCP_STATE_CLOSING:
2816 case TCP_STATE_LAST_ACK:
2819 case TCP_STATE_FIN_WAIT_1:
2820 tc0->state = TCP_STATE_CLOSING;
2821 tcp_program_ack (wrk, tc0);
2822 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2823 /* Wait for ACK but not forever */
2824 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2826 case TCP_STATE_FIN_WAIT_2:
2827 /* Got FIN, send ACK! Be more aggressive with resource cleanup */
2828 tc0->state = TCP_STATE_TIME_WAIT;
2829 tcp_connection_timers_reset (tc0);
2830 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2831 tcp_program_ack (wrk, tc0);
2832 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2834 case TCP_STATE_TIME_WAIT:
2835 /* Remain in the TIME-WAIT state. Restart the time-wait
2838 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
2841 error0 = TCP_ERROR_FIN_RCVD;
2842 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2846 tcp_inc_counter (rcv_process, error0, 1);
2847 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2849 tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2850 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2854 errors = session_manager_flush_enqueue_events (TRANSPORT_PROTO_TCP,
2856 tcp_inc_counter (rcv_process, TCP_ERROR_EVENT_FIFO_FULL, errors);
2857 tcp_handle_postponed_dequeues (wrk);
2858 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
2860 return from_frame->n_vectors;
2864 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2865 vlib_frame_t * from_frame)
2867 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2871 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2872 vlib_frame_t * from_frame)
2874 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2878 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2880 .function = tcp4_rcv_process,
2881 .name = "tcp4-rcv-process",
2882 /* Takes a vector of packets. */
2883 .vector_size = sizeof (u32),
2884 .n_errors = TCP_N_ERROR,
2885 .error_strings = tcp_error_strings,
2886 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2889 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2890 foreach_tcp_state_next
2893 .format_trace = format_tcp_rx_trace_short,
2897 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2900 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2902 .function = tcp6_rcv_process,
2903 .name = "tcp6-rcv-process",
2904 /* Takes a vector of packets. */
2905 .vector_size = sizeof (u32),
2906 .n_errors = TCP_N_ERROR,
2907 .error_strings = tcp_error_strings,
2908 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2911 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2912 foreach_tcp_state_next
2915 .format_trace = format_tcp_rx_trace_short,
2919 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2921 vlib_node_registration_t tcp4_listen_node;
2922 vlib_node_registration_t tcp6_listen_node;
2925 * LISTEN state processing as per RFC 793 p. 65
2928 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2929 vlib_frame_t * from_frame, int is_ip4)
2931 u32 n_left_from, *from, n_syns = 0, *first_buffer;
2932 u32 my_thread_index = vm->thread_index;
2934 from = first_buffer = vlib_frame_vector_args (from_frame);
2935 n_left_from = from_frame->n_vectors;
2937 while (n_left_from > 0)
2942 tcp_header_t *th0 = 0;
2943 tcp_connection_t *lc0;
2946 tcp_connection_t *child0;
2947 u32 error0 = TCP_ERROR_NONE;
2953 b0 = vlib_get_buffer (vm, bi0);
2954 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2958 ip40 = vlib_buffer_get_current (b0);
2959 th0 = ip4_next_header (ip40);
2963 ip60 = vlib_buffer_get_current (b0);
2964 th0 = ip6_next_header (ip60);
2967 /* Create child session. For syn-flood protection use filter */
2969 /* 1. first check for an RST: handled in dispatch */
2970 /* if (tcp_rst (th0))
2974 /* 2. second check for an ACK: handled in dispatch */
2975 /* if (tcp_ack (th0))
2977 tcp_send_reset (b0, is_ip4);
2982 /* 3. check for a SYN (did that already) */
2984 /* Make sure connection wasn't just created */
2985 child0 = tcp_lookup_connection (lc0->c_fib_index, b0, my_thread_index,
2987 if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
2989 error0 = TCP_ERROR_CREATE_EXISTS;
2993 /* Create child session and send SYN-ACK */
2994 child0 = tcp_connection_new (my_thread_index);
2995 child0->c_lcl_port = th0->dst_port;
2996 child0->c_rmt_port = th0->src_port;
2997 child0->c_is_ip4 = is_ip4;
2998 child0->state = TCP_STATE_SYN_RCVD;
2999 child0->c_fib_index = lc0->c_fib_index;
3003 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
3004 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
3008 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
3009 sizeof (ip6_address_t));
3010 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
3011 sizeof (ip6_address_t));
3014 if (tcp_options_parse (th0, &child0->rcv_opts))
3016 clib_warning ("options parse fail");
3020 child0->irs = vnet_buffer (b0)->tcp.seq_number;
3021 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
3022 child0->rcv_las = child0->rcv_nxt;
3023 child0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
3025 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
3026 * segments are used to initialize PAWS. */
3027 if (tcp_opts_tstamp (&child0->rcv_opts))
3029 child0->tsval_recent = child0->rcv_opts.tsval;
3030 child0->tsval_recent_age = tcp_time_now ();
3033 if (tcp_opts_wscale (&child0->rcv_opts))
3034 child0->snd_wscale = child0->rcv_opts.wscale;
3036 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
3037 << child0->snd_wscale;
3038 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
3039 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
3041 tcp_connection_init_vars (child0);
3042 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
3044 if (stream_session_accept (&child0->connection, lc0->c_s_index,
3047 clib_warning ("session accept fail");
3048 tcp_connection_cleanup (child0);
3049 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
3053 tcp_send_synack (child0);
3054 tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
3058 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
3060 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
3061 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
3062 clib_memcpy (&t0->tcp_connection, lc0, sizeof (t0->tcp_connection));
3065 n_syns += (error0 == TCP_ERROR_NONE);
3068 tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns);
3069 vlib_buffer_free (vm, first_buffer, from_frame->n_vectors);
3071 return from_frame->n_vectors;
3075 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3076 vlib_frame_t * from_frame)
3078 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3082 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
3083 vlib_frame_t * from_frame)
3085 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3089 VLIB_REGISTER_NODE (tcp4_listen_node) =
3091 .function = tcp4_listen,
3092 .name = "tcp4-listen",
3093 /* Takes a vector of packets. */
3094 .vector_size = sizeof (u32),
3095 .n_errors = TCP_N_ERROR,
3096 .error_strings = tcp_error_strings,
3097 .n_next_nodes = TCP_LISTEN_N_NEXT,
3100 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3101 foreach_tcp_state_next
3104 .format_trace = format_tcp_rx_trace_short,
3108 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
3111 VLIB_REGISTER_NODE (tcp6_listen_node) =
3113 .function = tcp6_listen,
3114 .name = "tcp6-listen",
3115 /* Takes a vector of packets. */
3116 .vector_size = sizeof (u32),
3117 .n_errors = TCP_N_ERROR,
3118 .error_strings = tcp_error_strings,
3119 .n_next_nodes = TCP_LISTEN_N_NEXT,
3122 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
3123 foreach_tcp_state_next
3126 .format_trace = format_tcp_rx_trace_short,
3130 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
3132 vlib_node_registration_t tcp4_input_node;
3133 vlib_node_registration_t tcp6_input_node;
3135 typedef enum _tcp_input_next
3137 TCP_INPUT_NEXT_DROP,
3138 TCP_INPUT_NEXT_LISTEN,
3139 TCP_INPUT_NEXT_RCV_PROCESS,
3140 TCP_INPUT_NEXT_SYN_SENT,
3141 TCP_INPUT_NEXT_ESTABLISHED,
3142 TCP_INPUT_NEXT_RESET,
3143 TCP_INPUT_NEXT_PUNT,
3147 #define foreach_tcp4_input_next \
3148 _ (DROP, "ip4-drop") \
3149 _ (LISTEN, "tcp4-listen") \
3150 _ (RCV_PROCESS, "tcp4-rcv-process") \
3151 _ (SYN_SENT, "tcp4-syn-sent") \
3152 _ (ESTABLISHED, "tcp4-established") \
3153 _ (RESET, "tcp4-reset") \
3154 _ (PUNT, "ip4-punt")
3156 #define foreach_tcp6_input_next \
3157 _ (DROP, "ip6-drop") \
3158 _ (LISTEN, "tcp6-listen") \
3159 _ (RCV_PROCESS, "tcp6-rcv-process") \
3160 _ (SYN_SENT, "tcp6-syn-sent") \
3161 _ (ESTABLISHED, "tcp6-established") \
3162 _ (RESET, "tcp6-reset") \
3163 _ (PUNT, "ip6-punt")
3165 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
3168 tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
3169 vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4)
3171 tcp_connection_t *tc;
3176 for (i = 0; i < n_bufs; i++)
3178 if (bs[i]->flags & VLIB_BUFFER_IS_TRACED)
3180 t = vlib_add_trace (vm, node, bs[i], sizeof (*t));
3181 tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index,
3183 tcp = vlib_buffer_get_current (bs[i]);
3184 tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4);
3190 tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4)
3192 if (*error == TCP_ERROR_FILTERED)
3194 *next = TCP_INPUT_NEXT_DROP;
3196 else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6))
3198 *next = TCP_INPUT_NEXT_PUNT;
3199 *error = TCP_ERROR_PUNT;
3203 *next = TCP_INPUT_NEXT_RESET;
3204 *error = TCP_ERROR_NO_LISTENER;
3208 static inline tcp_connection_t *
3209 tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error,
3212 u32 fib_index = vnet_buffer (b)->ip.fib_index;
3213 int n_advance_bytes, n_data_bytes;
3214 transport_connection_t *tc;
3220 ip4_header_t *ip4 = vlib_buffer_get_current (b);
3221 tcp = ip4_next_header (ip4);
3222 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4;
3223 n_advance_bytes = (ip4_header_bytes (ip4) + tcp_header_bytes (tcp));
3224 n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes;
3226 /* Length check. Checksum computed by ipx_local no need to compute again */
3227 if (PREDICT_FALSE (n_advance_bytes < 0))
3229 *error = TCP_ERROR_LENGTH;
3233 tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address,
3234 &ip4->src_address, tcp->dst_port,
3235 tcp->src_port, TRANSPORT_PROTO_TCP,
3236 thread_index, &is_filtered);
3240 ip6_header_t *ip6 = vlib_buffer_get_current (b);
3241 tcp = ip6_next_header (ip6);
3242 vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6;
3243 n_advance_bytes = tcp_header_bytes (tcp);
3244 n_data_bytes = clib_net_to_host_u16 (ip6->payload_length)
3246 n_advance_bytes += sizeof (ip6[0]);
3248 if (PREDICT_FALSE (n_advance_bytes < 0))
3250 *error = TCP_ERROR_LENGTH;
3254 tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address,
3255 &ip6->src_address, tcp->dst_port,
3256 tcp->src_port, TRANSPORT_PROTO_TCP,
3257 thread_index, &is_filtered);
3260 vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number);
3261 vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number);
3262 vnet_buffer (b)->tcp.data_offset = n_advance_bytes;
3263 vnet_buffer (b)->tcp.data_len = n_data_bytes;
3264 vnet_buffer (b)->tcp.flags = 0;
3266 *error = is_filtered ? TCP_ERROR_FILTERED : *error;
3268 return tcp_get_connection_from_transport (tc);
3272 tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc,
3273 vlib_buffer_t * b, u16 * next, u32 * error)
3278 tcp = tcp_buffer_hdr (b);
3279 flags = tcp->flags & filter_flags;
3280 *next = tm->dispatch_table[tc->state][flags].next;
3281 *error = tm->dispatch_table[tc->state][flags].error;
3283 if (PREDICT_FALSE (*error == TCP_ERROR_DISPATCH
3284 || *next == TCP_INPUT_NEXT_RESET))
3286 /* Overload tcp flags to store state */
3287 tcp_state_t state = tc->state;
3288 vnet_buffer (b)->tcp.flags = tc->state;
3290 if (*error == TCP_ERROR_DISPATCH)
3291 clib_warning ("disp error state %U flags %U", format_tcp_state,
3292 state, format_tcp_flags, (int) flags);
3297 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
3298 vlib_frame_t * frame, int is_ip4)
3300 u32 n_left_from, *from, thread_index = vm->thread_index;
3301 tcp_main_t *tm = vnet_get_tcp_main ();
3302 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
3303 u16 nexts[VLIB_FRAME_SIZE], *next;
3305 tcp_set_time_now (tcp_get_worker (thread_index));
3307 from = vlib_frame_vector_args (frame);
3308 n_left_from = frame->n_vectors;
3309 vlib_get_buffers (vm, from, bufs, n_left_from);
3314 while (n_left_from >= 4)
3316 u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER;
3317 tcp_connection_t *tc0, *tc1;
3320 vlib_prefetch_buffer_header (b[2], STORE);
3321 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3323 vlib_prefetch_buffer_header (b[3], STORE);
3324 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3327 next[0] = next[1] = TCP_INPUT_NEXT_DROP;
3329 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3330 tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4);
3332 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
3334 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3335 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3337 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3338 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3340 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3341 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3345 if (PREDICT_TRUE (tc0 != 0))
3347 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3348 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3349 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3352 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3354 if (PREDICT_TRUE (tc1 != 0))
3356 ASSERT (tcp_lookup_is_valid (tc1, tcp_buffer_hdr (b[1])));
3357 vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index;
3358 tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], &error1);
3361 tcp_input_set_error_next (tm, &next[1], &error1, is_ip4);
3368 while (n_left_from > 0)
3370 tcp_connection_t *tc0;
3371 u32 error0 = TCP_ERROR_NO_LISTENER;
3373 if (n_left_from > 1)
3375 vlib_prefetch_buffer_header (b[1], STORE);
3376 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
3379 next[0] = TCP_INPUT_NEXT_DROP;
3380 tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4);
3381 if (PREDICT_TRUE (tc0 != 0))
3383 ASSERT (tcp_lookup_is_valid (tc0, tcp_buffer_hdr (b[0])));
3384 vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index;
3385 tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], &error0);
3388 tcp_input_set_error_next (tm, &next[0], &error0, is_ip4);
3395 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
3396 tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4);
3398 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
3399 return frame->n_vectors;
3403 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3404 vlib_frame_t * from_frame)
3406 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
3410 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
3411 vlib_frame_t * from_frame)
3413 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
3417 VLIB_REGISTER_NODE (tcp4_input_node) =
3419 .function = tcp4_input,
3420 .name = "tcp4-input",
3421 /* Takes a vector of packets. */
3422 .vector_size = sizeof (u32),
3423 .n_errors = TCP_N_ERROR,
3424 .error_strings = tcp_error_strings,
3425 .n_next_nodes = TCP_INPUT_N_NEXT,
3428 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3429 foreach_tcp4_input_next
3432 .format_buffer = format_tcp_header,
3433 .format_trace = format_tcp_rx_trace,
3437 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
3440 VLIB_REGISTER_NODE (tcp6_input_node) =
3442 .function = tcp6_input,
3443 .name = "tcp6-input",
3444 /* Takes a vector of packets. */
3445 .vector_size = sizeof (u32),
3446 .n_errors = TCP_N_ERROR,
3447 .error_strings = tcp_error_strings,
3448 .n_next_nodes = TCP_INPUT_N_NEXT,
3451 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
3452 foreach_tcp6_input_next
3455 .format_buffer = format_tcp_header,
3456 .format_trace = format_tcp_rx_trace,
3460 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
3463 tcp_dispatch_table_init (tcp_main_t * tm)
3466 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
3467 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
3469 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
3470 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
3473 #define _(t,f,n,e) \
3475 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
3476 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
3479 /* SYNs for new connections -> tcp-listen. */
3480 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
3481 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
3482 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_RST_RCVD);
3483 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3485 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
3486 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3487 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3488 _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3490 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3491 _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3493 /* SYN-ACK for a SYN */
3494 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3496 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3497 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3498 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3500 /* ACK for for established connection -> tcp-established. */
3501 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3502 /* FIN for for established connection -> tcp-established. */
3503 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3504 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3506 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3507 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3509 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3510 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3512 /* ACK or FIN-ACK to our FIN */
3513 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3514 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3516 /* FIN in reply to our FIN from the other side */
3517 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3518 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3519 _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3520 /* FIN confirming that the peer (app) has closed */
3521 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3522 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3523 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3525 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3526 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3528 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3529 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3530 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3532 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3533 _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3534 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3535 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3537 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3538 _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3539 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3540 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3541 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
3542 TCP_ERROR_CONNECTION_CLOSED);
3546 static clib_error_t *
3547 tcp_input_init (vlib_main_t * vm)
3549 clib_error_t *error = 0;
3550 tcp_main_t *tm = vnet_get_tcp_main ();
3552 if ((error = vlib_call_init_function (vm, tcp_init)))
3555 /* Initialize dispatch table. */
3556 tcp_dispatch_table_init (tm);
3561 VLIB_INIT_FUNCTION (tcp_input_init);
3564 * fd.io coding-style-patch-verification: ON
3567 * eval: (c-set-style "gnu")