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 _ (DROP, "error-drop") \
31 _ (TCP4_OUTPUT, "tcp4-output") \
32 _ (TCP6_OUTPUT, "tcp6-output")
34 typedef enum _tcp_established_next
36 #define _(s,n) TCP_ESTABLISHED_NEXT_##s,
37 foreach_tcp_state_next
39 TCP_ESTABLISHED_N_NEXT,
40 } tcp_established_next_t;
42 typedef enum _tcp_rcv_process_next
44 #define _(s,n) TCP_RCV_PROCESS_NEXT_##s,
45 foreach_tcp_state_next
47 TCP_RCV_PROCESS_N_NEXT,
48 } tcp_rcv_process_next_t;
50 typedef enum _tcp_syn_sent_next
52 #define _(s,n) TCP_SYN_SENT_NEXT_##s,
53 foreach_tcp_state_next
56 } tcp_syn_sent_next_t;
58 typedef enum _tcp_listen_next
60 #define _(s,n) TCP_LISTEN_NEXT_##s,
61 foreach_tcp_state_next
66 /* Generic, state independent indices */
67 typedef enum _tcp_state_next
69 #define _(s,n) TCP_NEXT_##s,
70 foreach_tcp_state_next
75 #define tcp_next_output(is_ip4) (is_ip4 ? TCP_NEXT_TCP4_OUTPUT \
76 : TCP_NEXT_TCP6_OUTPUT)
78 vlib_node_registration_t tcp4_established_node;
79 vlib_node_registration_t tcp6_established_node;
82 * Validate segment sequence number. As per RFC793:
84 * Segment Receive Test
86 * ------- ------- -------------------------------------------
87 * 0 0 SEG.SEQ = RCV.NXT
88 * 0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
90 * >0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
91 * or RCV.NXT =< SEG.SEQ+SEG.LEN-1 < RCV.NXT+RCV.WND
93 * This ultimately consists in checking if segment falls within the window.
94 * The one important difference compared to RFC793 is that we use rcv_las,
95 * or the rcv_nxt at last ack sent instead of rcv_nxt since that's the
96 * peer's reference when computing our receive window.
99 * seq_leq (end_seq, tc->rcv_las + tc->rcv_wnd) && seq_geq (seq, tc->rcv_las)
100 * however, is too strict when we have retransmits. Instead we just check that
101 * the seq is not beyond the right edge and that the end of the segment is not
102 * less than the left edge.
104 * N.B. rcv_nxt and rcv_wnd are both updated in this node if acks are sent, so
105 * use rcv_nxt in the right edge window test instead of rcv_las.
109 tcp_segment_in_rcv_wnd (tcp_connection_t * tc, u32 seq, u32 end_seq)
111 return (seq_geq (end_seq, tc->rcv_las)
112 && seq_leq (seq, tc->rcv_nxt + tc->rcv_wnd));
116 * Parse TCP header options.
118 * @param th TCP header
119 * @param to TCP options data structure to be populated
120 * @return -1 if parsing failed
123 tcp_options_parse (tcp_header_t * th, tcp_options_t * to)
126 u8 opt_len, opts_len, kind;
130 opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t);
131 data = (const u8 *) (th + 1);
133 /* Zero out all flags but those set in SYN */
134 to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE);
136 for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
140 /* Get options length */
141 if (kind == TCP_OPTION_EOL)
143 else if (kind == TCP_OPTION_NOOP)
155 /* weird option length */
156 if (opt_len < 2 || opt_len > opts_len)
164 if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
166 to->flags |= TCP_OPTS_FLAG_MSS;
167 to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
170 case TCP_OPTION_WINDOW_SCALE:
171 if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
173 to->flags |= TCP_OPTS_FLAG_WSCALE;
174 to->wscale = data[2];
175 if (to->wscale > TCP_MAX_WND_SCALE)
177 clib_warning ("Illegal window scaling value: %d",
179 to->wscale = TCP_MAX_WND_SCALE;
183 case TCP_OPTION_TIMESTAMP:
184 if (opt_len == TCP_OPTION_LEN_TIMESTAMP)
186 to->flags |= TCP_OPTS_FLAG_TSTAMP;
187 to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
188 to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
191 case TCP_OPTION_SACK_PERMITTED:
192 if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
193 to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
195 case TCP_OPTION_SACK_BLOCK:
196 /* If SACK permitted was not advertised or a SYN, break */
197 if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
200 /* If too short or not correctly formatted, break */
201 if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
204 to->flags |= TCP_OPTS_FLAG_SACK;
205 to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
206 vec_reset_length (to->sacks);
207 for (j = 0; j < to->n_sack_blocks; j++)
209 b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 4 * j));
210 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 4 * j));
211 vec_add1 (to->sacks, b);
215 /* Nothing to see here */
223 * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
224 * timestamp to echo and it's less than tsval_recent, drop segment
225 * but still send an ACK in order to retain TCP's mechanism for detecting
226 * and recovering from half-open connections
228 * Or at least that's what the theory says. It seems that this might not work
229 * very well with packet reordering and fast retransmit. XXX
232 tcp_segment_check_paws (tcp_connection_t * tc)
234 return tcp_opts_tstamp (&tc->rcv_opts) && tc->tsval_recent
235 && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent);
239 * Update tsval recent
242 tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
245 * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
246 * of an incoming segment:
247 * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
248 * then the TSval from the segment is copied to TS.Recent;
249 * otherwise, the TSval is ignored.
251 if (tcp_opts_tstamp (&tc->rcv_opts) && tc->tsval_recent
252 && seq_leq (seq, tc->rcv_las) && seq_leq (tc->rcv_las, seq_end))
254 ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval));
255 tc->tsval_recent = tc->rcv_opts.tsval;
256 tc->tsval_recent_age = tcp_time_now ();
261 * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
263 * It first verifies if segment has a wrapped sequence number (PAWS) and then
264 * does the processing associated to the first four steps (ignoring security
265 * and precedence): sequence number, rst bit and syn bit checks.
267 * @return 0 if segments passes validation.
270 tcp_segment_validate (vlib_main_t * vm, tcp_connection_t * tc0,
271 vlib_buffer_t * b0, tcp_header_t * th0, u32 * next0)
273 if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
276 if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts)))
281 if (tcp_segment_check_paws (tc0))
285 clib_warning ("paws failed\n%U", format_tcp_connection, tc0, 2);
286 clib_warning ("seq %u seq_end %u ack %u",
287 vnet_buffer (b0)->tcp.seq_number - tc0->irs,
288 vnet_buffer (b0)->tcp.seq_end - tc0->irs,
289 vnet_buffer (b0)->tcp.ack_number - tc0->iss);
291 TCP_EVT_DBG (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
292 vnet_buffer (b0)->tcp.seq_end);
294 /* If it just so happens that a segment updates tsval_recent for a
295 * segment over 24 days old, invalidate tsval_recent. */
296 if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
299 /* Age isn't reset until we get a valid tsval (bsd inspired) */
300 tc0->tsval_recent = 0;
301 clib_warning ("paws failed - really old segment. REALLY?");
305 /* Drop after ack if not rst */
308 tcp_make_ack (tc0, b0);
309 *next0 = tcp_next_output (tc0->c_is_ip4);
310 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0);
316 /* 1st: check sequence number */
317 if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
318 vnet_buffer (b0)->tcp.seq_end))
320 /* If our window is 0 and the packet is in sequence, let it pass
321 * through for ack processing. It should be dropped later.*/
322 if (tc0->rcv_wnd == 0
323 && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number)
325 /* TODO Should segment be tagged? */
329 /* If not RST, send dup ack */
332 tcp_make_ack (tc0, b0);
333 *next0 = tcp_next_output (tc0->c_is_ip4);
334 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0);
340 /* 2nd: check the RST bit */
343 tcp_connection_reset (tc0);
347 /* 3rd: check security and precedence (skip) */
349 /* 4th: check the SYN bit */
352 tcp_send_reset (b0, tc0->c_is_ip4);
356 /* If segment in window, save timestamp */
357 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
358 vnet_buffer (b0)->tcp.seq_end);
363 tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0)
365 /* SND.UNA =< SEG.ACK =< SND.NXT */
366 return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number)
367 && seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt));
371 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
373 * Note that although the original article, srtt and rttvar are scaled
374 * to minimize round-off errors, here we don't. Instead, we rely on
375 * better precision time measurements.
377 * TODO support us rtt resolution
380 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
386 err = mrtt - tc->srtt;
388 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
389 * The increase should be bound */
390 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
391 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
392 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
396 /* First measurement. */
398 tc->rttvar = mrtt >> 1;
403 tcp_update_rto (tcp_connection_t * tc)
405 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
406 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
409 /** Update RTT estimate and RTO timer
411 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
412 * timing. Middle boxes are known to fiddle with TCP options so we
413 * should give higher priority to ACK timing.
415 * return 1 if valid rtt 0 otherwise
418 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
423 /* Determine if only rtx bytes are acked. */
424 rtx_acked = tcp_in_cong_recovery (tc) || !tc->bytes_acked;
426 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
427 * RTT because they're ambiguous. */
428 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq) && !rtx_acked)
430 mrtt = tcp_time_now () - tc->rtt_ts;
432 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
433 * snd_una, i.e., the left side of the send window:
434 * seq_lt (tc->snd_una, ack). */
435 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr
438 mrtt = tcp_time_now () - tc->rcv_opts.tsecr;
441 /* Allow measuring of a new RTT */
444 /* If ACK moves left side of the wnd make sure boff is 0, even if mrtt is
449 /* Ignore dubious measurements */
450 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
453 tcp_estimate_rtt (tc, mrtt);
460 * Dequeue bytes that have been acked and while at it update RTT estimates.
463 tcp_dequeue_acked (tcp_connection_t * tc, u32 ack)
465 /* Dequeue the newly ACKed add SACKed bytes */
466 stream_session_dequeue_drop (&tc->connection,
467 tc->bytes_acked + tc->sack_sb.snd_una_adv);
469 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
471 /* Update rtt and rto */
472 tcp_update_rtt (tc, ack);
474 /* If everything has been acked, stop retransmit timer
475 * otherwise update. */
476 tcp_retransmit_timer_update (tc);
480 * Check if duplicate ack as per RFC5681 Sec. 2
483 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
486 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
487 && seq_gt (tc->snd_una_max, tc->snd_una)
488 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
489 && (prev_snd_wnd == tc->snd_wnd));
493 tcp_is_lost_fin (tcp_connection_t * tc)
495 if ((tc->flags & TCP_CONN_FINSNT) && tc->snd_una_max - tc->snd_una == 1)
501 * Checks if ack is a congestion control event.
504 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
505 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
507 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
508 * defined to be 'duplicate' */
509 *is_dack = tc->sack_sb.last_sacked_bytes
510 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
512 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
516 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
518 sack_scoreboard_hole_t *next, *prev;
520 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
522 next = pool_elt_at_index (sb->holes, hole->next);
523 next->prev = hole->prev;
527 sb->tail = hole->prev;
530 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
532 prev = pool_elt_at_index (sb->holes, hole->prev);
533 prev->next = hole->next;
537 sb->head = hole->next;
540 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
541 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
543 pool_put (sb->holes, hole);
546 sack_scoreboard_hole_t *
547 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
550 sack_scoreboard_hole_t *hole, *next, *prev;
553 pool_get (sb->holes, hole);
554 memset (hole, 0, sizeof (*hole));
558 hole_index = hole - sb->holes;
560 prev = scoreboard_get_hole (sb, prev_index);
563 hole->prev = prev_index;
564 hole->next = prev->next;
566 if ((next = scoreboard_next_hole (sb, hole)))
567 next->prev = hole_index;
569 sb->tail = hole_index;
571 prev->next = hole_index;
575 sb->head = hole_index;
576 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
577 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
584 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
586 sack_scoreboard_hole_t *hole, *prev;
587 u32 bytes = 0, blks = 0;
590 sb->sacked_bytes = 0;
591 hole = scoreboard_last_hole (sb);
595 if (seq_gt (sb->high_sacked, hole->end))
597 bytes = sb->high_sacked - hole->end;
601 while ((prev = scoreboard_prev_hole (sb, hole))
602 && (bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
603 && blks < TCP_DUPACK_THRESHOLD))
605 bytes += hole->start - prev->end;
612 sb->lost_bytes += scoreboard_hole_bytes (hole);
615 hole = scoreboard_prev_hole (sb, hole);
617 bytes += prev->start - hole->end;
619 sb->sacked_bytes = bytes;
623 * Figure out the next hole to retransmit
625 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
627 sack_scoreboard_hole_t *
628 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
629 sack_scoreboard_hole_t * start,
631 u8 * can_rescue, u8 * snd_limited)
633 sack_scoreboard_hole_t *hole = 0;
635 hole = start ? start : scoreboard_first_hole (sb);
636 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
637 hole = scoreboard_next_hole (sb, hole);
639 /* Nothing, return */
642 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
646 /* Rule (1): if higher than rxt, less than high_sacked and lost */
647 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
649 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
653 /* Rule (2): output takes care of transmitting new data */
654 if (!have_sent_1_smss)
657 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
659 /* Rule (3): if hole not lost */
660 else if (seq_lt (hole->start, sb->high_sacked))
663 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
665 /* Rule (4): if hole beyond high_sacked */
668 ASSERT (seq_geq (hole->start, sb->high_sacked));
671 /* HighRxt MUST NOT be updated */
676 if (hole && seq_lt (sb->high_rxt, hole->start))
677 sb->high_rxt = hole->start;
683 scoreboard_init_high_rxt (sack_scoreboard_t * sb)
685 sack_scoreboard_hole_t *hole;
686 hole = scoreboard_first_hole (sb);
687 sb->high_rxt = hole->start;
688 sb->cur_rxt_hole = sb->head;
692 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
694 sack_scoreboard_t *sb = &tc->sack_sb;
695 sack_block_t *blk, tmp;
696 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
697 u32 blk_index = 0, old_sacked_bytes, hole_index;
700 sb->last_sacked_bytes = 0;
702 old_sacked_bytes = sb->sacked_bytes;
703 sb->last_bytes_delivered = 0;
705 if (!tcp_opts_sack (&tc->rcv_opts)
706 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
709 /* Remove invalid blocks */
710 blk = tc->rcv_opts.sacks;
711 while (blk < vec_end (tc->rcv_opts.sacks))
713 if (seq_lt (blk->start, blk->end)
714 && seq_gt (blk->start, tc->snd_una)
715 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_nxt))
720 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
723 /* Add block for cumulative ack */
724 if (seq_gt (ack, tc->snd_una))
726 tmp.start = tc->snd_una;
728 vec_add1 (tc->rcv_opts.sacks, tmp);
731 if (vec_len (tc->rcv_opts.sacks) == 0)
734 /* Make sure blocks are ordered */
735 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
736 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
737 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
739 tmp = tc->rcv_opts.sacks[i];
740 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
741 tc->rcv_opts.sacks[j] = tmp;
744 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
746 /* If no holes, insert the first that covers all outstanding bytes */
747 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
748 tc->snd_una, tc->snd_una_max);
749 sb->tail = scoreboard_hole_index (sb, last_hole);
750 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
751 sb->high_sacked = tmp.end;
755 /* If we have holes but snd_una_max is beyond the last hole, update
757 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
758 last_hole = scoreboard_last_hole (sb);
759 if (seq_gt (tc->snd_una_max, last_hole->end))
761 if (seq_geq (last_hole->start, sb->high_sacked))
763 last_hole->end = tc->snd_una_max;
765 /* New hole after high sacked block */
766 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
768 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
772 /* Keep track of max byte sacked for when the last hole
774 if (seq_gt (tmp.end, sb->high_sacked))
775 sb->high_sacked = tmp.end;
778 /* Walk the holes with the SACK blocks */
779 hole = pool_elt_at_index (sb->holes, sb->head);
780 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
782 blk = &tc->rcv_opts.sacks[blk_index];
783 if (seq_leq (blk->start, hole->start))
785 /* Block covers hole. Remove hole */
786 if (seq_geq (blk->end, hole->end))
788 next_hole = scoreboard_next_hole (sb, hole);
790 /* Byte accounting: snd_una needs to be advanced */
795 if (seq_lt (ack, next_hole->start))
796 sb->snd_una_adv = next_hole->start - ack;
797 sb->last_bytes_delivered +=
798 next_hole->start - hole->end;
802 ASSERT (seq_geq (sb->high_sacked, ack));
803 sb->snd_una_adv = sb->high_sacked - ack;
804 sb->last_bytes_delivered += sb->high_sacked - hole->end;
808 scoreboard_remove_hole (sb, hole);
811 /* Partial 'head' overlap */
814 if (seq_gt (blk->end, hole->start))
816 hole->start = blk->end;
823 /* Hole must be split */
824 if (seq_lt (blk->end, hole->end))
826 hole_index = scoreboard_hole_index (sb, hole);
827 scoreboard_insert_hole (sb, hole_index, blk->end, hole->end);
829 /* Pool might've moved */
830 hole = scoreboard_get_hole (sb, hole_index);
831 hole->end = blk->start;
834 else if (seq_lt (blk->start, hole->end))
836 hole->end = blk->start;
838 hole = scoreboard_next_hole (sb, hole);
842 scoreboard_update_bytes (tc, sb);
843 sb->last_sacked_bytes = sb->sacked_bytes
844 - (old_sacked_bytes - sb->last_bytes_delivered);
845 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes);
846 ASSERT (sb->sacked_bytes == 0
847 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
848 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
849 - seq_max (tc->snd_una, ack));
850 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
851 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
855 * Try to update snd_wnd based on feedback received from peer.
857 * If successful, and new window is 'effectively' 0, activate persist
861 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
863 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
864 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
865 if (seq_lt (tc->snd_wl1, seq)
866 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
868 tc->snd_wnd = snd_wnd;
871 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
873 if (tc->snd_wnd < tc->snd_mss)
875 /* Set persist timer if not set and we just got 0 wnd */
876 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
877 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
878 tcp_persist_timer_set (tc);
882 tcp_persist_timer_reset (tc);
883 if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
893 tcp_cc_init_congestion (tcp_connection_t * tc)
895 tcp_fastrecovery_on (tc);
896 tc->snd_congestion = tc->snd_una_max;
897 tc->cc_algo->congestion (tc);
898 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
902 tcp_cc_recovery_exit (tcp_connection_t * tc)
908 tcp_recovery_off (tc);
912 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
914 tc->cc_algo->recovered (tc);
915 tc->snd_rxt_bytes = 0;
917 tcp_fastrecovery_off (tc);
918 tcp_fastrecovery_1_smss_off (tc);
922 tcp_cc_congestion_undo (tcp_connection_t * tc)
924 tc->cwnd = tc->prev_cwnd;
925 tc->ssthresh = tc->prev_ssthresh;
926 tc->snd_nxt = tc->snd_una_max;
928 if (tcp_in_recovery (tc))
929 tcp_cc_recovery_exit (tc);
930 ASSERT (tc->rto_boff == 0);
931 /* TODO extend for fastrecovery */
935 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
937 return (tcp_in_recovery (tc)
939 && tcp_opts_tstamp (&tc->rcv_opts)
940 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
944 tcp_cc_recover (tcp_connection_t * tc)
946 ASSERT (tcp_in_cong_recovery (tc));
947 if (tcp_cc_is_spurious_retransmit (tc))
949 tcp_cc_congestion_undo (tc);
953 if (tcp_in_recovery (tc))
954 tcp_cc_recovery_exit (tc);
955 else if (tcp_in_fastrecovery (tc))
956 tcp_cc_fastrecovery_exit (tc);
958 ASSERT (tc->rto_boff == 0);
959 ASSERT (!tcp_in_cong_recovery (tc));
961 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
966 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
968 ASSERT (!tcp_in_cong_recovery (tc));
970 /* Congestion avoidance */
971 tc->cc_algo->rcv_ack (tc);
972 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
974 /* If a cumulative ack, make sure dupacks is 0 */
977 /* When dupacks hits the threshold we only enter fast retransmit if
978 * cumulative ack covers more than snd_congestion. Should snd_una
979 * wrap this test may fail under otherwise valid circumstances.
980 * Therefore, proactively update snd_congestion when wrap detected. */
982 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
983 && seq_gt (tc->snd_congestion, tc->snd_una)))
984 tc->snd_congestion = tc->snd_una - 1;
988 tcp_should_fastrecover_sack (tcp_connection_t * tc)
990 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
994 tcp_should_fastrecover (tcp_connection_t * tc)
996 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
997 || tcp_should_fastrecover_sack (tc));
1001 * One function to rule them all ... and in the darkness bind them
1004 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1009 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1010 * it account for the bytes that left the network.
1014 ASSERT (tc->snd_una != tc->snd_una_max
1015 || tc->sack_sb.last_sacked_bytes);
1019 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1021 ASSERT (tcp_in_fastrecovery (tc));
1022 /* Pure duplicate ack. If some data got acked, it's handled lower */
1023 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1026 else if (tcp_should_fastrecover (tc))
1028 /* Things are already bad */
1029 if (tcp_in_cong_recovery (tc))
1031 tc->rcv_dupacks = 0;
1032 goto partial_ack_test;
1035 /* If of of the two conditions lower hold, reset dupacks because
1036 * we're probably after timeout (RFC6582 heuristics).
1037 * If Cumulative ack does not cover more than congestion threshold,
1039 * 1) The following doesn't hold: The congestion window is greater
1040 * than SMSS bytes and the difference between highest_ack
1041 * and prev_highest_ack is at most 4*SMSS bytes
1042 * 2) Echoed timestamp in the last non-dup ack does not equal the
1045 if (seq_leq (tc->snd_una, tc->snd_congestion)
1046 && ((!(tc->cwnd > tc->snd_mss
1047 && tc->bytes_acked <= 4 * tc->snd_mss))
1048 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1050 tc->rcv_dupacks = 0;
1054 tcp_cc_init_congestion (tc);
1055 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1057 /* The first segment MUST be retransmitted */
1058 tcp_retransmit_first_unacked (tc);
1060 /* Post retransmit update cwnd to ssthresh and account for the
1061 * three segments that have left the network and should've been
1062 * buffered at the receiver XXX */
1063 tc->cwnd = tc->ssthresh + tc->rcv_dupacks * tc->snd_mss;
1064 ASSERT (tc->cwnd >= tc->snd_mss);
1066 /* If cwnd allows, send more data */
1067 if (tcp_opts_sack_permitted (&tc->rcv_opts)
1068 && scoreboard_first_hole (&tc->sack_sb))
1070 scoreboard_init_high_rxt (&tc->sack_sb);
1071 tcp_fast_retransmit_sack (tc);
1075 tcp_fast_retransmit_no_sack (tc);
1080 else if (!tc->bytes_acked
1081 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1083 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1092 if (!tc->bytes_acked)
1097 * Legitimate ACK. 1) See if we can exit recovery
1099 /* XXX limit this only to first partial ack? */
1100 tcp_retransmit_timer_update (tc);
1102 if (seq_geq (tc->snd_una, tc->snd_congestion))
1104 /* If spurious return, we've already updated everything */
1105 if (tcp_cc_recover (tc))
1107 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1111 tc->snd_nxt = tc->snd_una_max;
1113 /* Treat as congestion avoidance ack */
1114 tc->cc_algo->rcv_ack (tc);
1115 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1120 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1122 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1124 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1125 * reset dupacks to 0 */
1126 tc->rcv_dupacks = 0;
1128 tcp_retransmit_first_unacked (tc);
1130 /* Post RTO timeout don't try anything fancy */
1131 if (tcp_in_recovery (tc))
1134 /* Remove retransmitted bytes that have been delivered */
1135 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1136 >= tc->sack_sb.last_bytes_delivered);
1137 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1138 - tc->sack_sb.last_bytes_delivered;
1139 if (0 && rxt_delivered && seq_gt (tc->sack_sb.high_rxt, tc->snd_una))
1141 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1142 * remove sacked bytes delivered */
1143 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1144 tc->snd_rxt_bytes -= rxt_delivered;
1148 /* Either all retransmitted holes have been acked, or we're
1149 * "in the blind" and retransmitting segment by segment */
1150 tc->snd_rxt_bytes = 0;
1153 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1156 * Since this was a partial ack, try to retransmit some more data
1158 tcp_fast_retransmit (tc);
1162 tcp_cc_init (tcp_connection_t * tc)
1164 tc->cc_algo = tcp_cc_algo_get (TCP_CC_NEWRENO);
1165 tc->cc_algo->init (tc);
1169 * Process incoming ACK
1172 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
1173 tcp_header_t * th, u32 * next, u32 * error)
1175 u32 prev_snd_wnd, prev_snd_una;
1178 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1180 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1181 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1183 /* If we have outstanding data and this is within the window, accept it,
1184 * probably retransmit has timed out. Otherwise ACK segment and then
1186 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1188 tcp_make_ack (tc, b);
1189 *next = tcp_next_output (tc->c_is_ip4);
1190 *error = TCP_ERROR_ACK_INVALID;
1191 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1192 vnet_buffer (b)->tcp.ack_number);
1196 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1197 vnet_buffer (b)->tcp.ack_number);
1199 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1200 *error = TCP_ERROR_ACK_FUTURE;
1203 /* If old ACK, probably it's an old dupack */
1204 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1206 *error = TCP_ERROR_ACK_OLD;
1207 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1208 vnet_buffer (b)->tcp.ack_number);
1209 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1211 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc);
1212 tcp_cc_handle_event (tc, 1);
1214 /* Don't drop yet */
1219 * Looks okay, process feedback
1222 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1224 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1225 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1227 prev_snd_wnd = tc->snd_wnd;
1228 prev_snd_una = tc->snd_una;
1229 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1230 vnet_buffer (b)->tcp.ack_number,
1231 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1232 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1233 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1234 tcp_validate_txf_size (tc, tc->bytes_acked);
1236 if (tc->bytes_acked)
1237 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
1240 * Check if we have congestion event
1243 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1245 tcp_cc_handle_event (tc, is_dack);
1246 *error = TCP_ERROR_ACK_DUP;
1247 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1248 return vnet_buffer (b)->tcp.data_len ? 0 : -1;
1252 * Update congestion control (slow start/congestion avoidance)
1254 tcp_cc_update (tc, b);
1260 * Build SACK list as per RFC2018.
1262 * Makes sure the first block contains the segment that generated the current
1263 * ACK and the following ones are the ones most recently reported in SACK
1266 * @param tc TCP connection for which the SACK list is updated
1267 * @param start Start sequence number of the newest SACK block
1268 * @param end End sequence of the newest SACK block
1271 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1273 sack_block_t *new_list = 0, *block = 0;
1276 /* If the first segment is ooo add it to the list. Last write might've moved
1277 * rcv_nxt over the first segment. */
1278 if (seq_lt (tc->rcv_nxt, start))
1280 vec_add2 (new_list, block, 1);
1281 block->start = start;
1285 /* Find the blocks still worth keeping. */
1286 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1288 /* Discard if rcv_nxt advanced beyond current block */
1289 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1292 /* Merge or drop if segment overlapped by the new segment */
1293 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1294 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1296 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1297 new_list[0].start = tc->snd_sacks[i].start;
1298 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1299 new_list[0].end = tc->snd_sacks[i].end;
1303 /* Save to new SACK list if we have space. */
1304 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1306 vec_add1 (new_list, tc->snd_sacks[i]);
1310 clib_warning ("sack discarded");
1314 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1316 /* Replace old vector with new one */
1317 vec_free (tc->snd_sacks);
1318 tc->snd_sacks = new_list;
1321 /** Enqueue data for delivery to application */
1323 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1328 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1330 /* Pure ACK. Update rcv_nxt and be done. */
1331 if (PREDICT_FALSE (data_len == 0))
1333 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end;
1334 return TCP_ERROR_PURE_ACK;
1337 written = stream_session_enqueue_data (&tc->connection, b, 0,
1338 1 /* queue event */ , 1);
1340 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1342 /* Update rcv_nxt */
1343 if (PREDICT_TRUE (written == data_len))
1345 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end;
1347 /* If more data written than expected, account for out-of-order bytes. */
1348 else if (written > data_len)
1350 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end + written - data_len;
1352 /* Send ACK confirming the update */
1353 tc->flags |= TCP_CONN_SNDACK;
1355 else if (written > 0)
1357 /* We've written something but FIFO is probably full now */
1358 tc->rcv_nxt += written;
1360 /* Depending on how fast the app is, all remaining buffers in burst will
1361 * not be enqueued. Inform peer */
1362 tc->flags |= TCP_CONN_SNDACK;
1364 return TCP_ERROR_PARTIALLY_ENQUEUED;
1368 tc->flags |= TCP_CONN_SNDACK;
1369 return TCP_ERROR_FIFO_FULL;
1372 /* Update SACK list if need be */
1373 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1375 /* Remove SACK blocks that have been delivered */
1376 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1379 return TCP_ERROR_ENQUEUED;
1382 /** Enqueue out-of-order data */
1384 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1387 stream_session_t *s0;
1390 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1392 /* Pure ACK. Do nothing */
1393 if (PREDICT_FALSE (data_len == 0))
1395 return TCP_ERROR_PURE_ACK;
1398 /* Enqueue out-of-order data with relative offset */
1399 rv = stream_session_enqueue_data (&tc->connection, b,
1400 vnet_buffer (b)->tcp.seq_number -
1401 tc->rcv_nxt, 0 /* queue event */ , 0);
1403 /* Nothing written */
1406 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1407 return TCP_ERROR_FIFO_FULL;
1410 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1412 /* Update SACK list if in use */
1413 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1415 ooo_segment_t *newest;
1418 s0 = stream_session_get (tc->c_s_index, tc->c_thread_index);
1420 /* Get the newest segment from the fifo */
1421 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1425 tc->rcv_nxt + ooo_segment_offset (s0->server_rx_fifo, newest);
1426 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1427 tcp_update_sack_list (tc, start, end);
1429 ASSERT (seq_gt (start, tc->rcv_nxt));
1433 return TCP_ERROR_ENQUEUED;
1437 * Check if ACK could be delayed. If ack can be delayed, it should return
1438 * true for a full frame. If we're always acking return 0.
1441 tcp_can_delack (tcp_connection_t * tc)
1443 /* Send ack if ... */
1445 /* just sent a rcv wnd 0 */
1446 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1447 /* constrained to send ack */
1448 || (tc->flags & TCP_CONN_SNDACK) != 0
1449 /* we're almost out of tx wnd */
1450 || tcp_available_snd_space (tc) < 4 * tc->snd_mss)
1457 tcp_segment_rcv (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b,
1458 u16 n_data_bytes, u32 * next0)
1460 u32 error = 0, n_bytes_to_drop;
1462 /* Handle out-of-order data */
1463 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1465 /* Old sequence numbers allowed through because they overlapped
1467 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1469 error = TCP_ERROR_SEGMENT_OLD;
1470 *next0 = TCP_NEXT_DROP;
1472 /* Completely in the past (possible retransmit) */
1473 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1476 /* Chop off the bytes in the past */
1477 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1478 n_data_bytes -= n_bytes_to_drop;
1479 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1480 vlib_buffer_advance (b, n_bytes_to_drop);
1485 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1487 /* N.B. Should not filter burst of dupacks. Two issues 1) dupacks open
1488 * cwnd on remote peer when congested 2) acks leaving should have the
1489 * latest rcv_wnd since the burst may eaten up all of it, so only the
1490 * old ones could be filtered.
1493 /* RFC2581: Send DUPACK for fast retransmit */
1494 tcp_make_ack (tc, b);
1495 *next0 = tcp_next_output (tc->c_is_ip4);
1497 /* Mark as DUPACK. We may filter these in output if
1498 * the burst fills the holes. */
1500 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1502 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc);
1508 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1509 * segments can be enqueued after fifo tail offset changes. */
1510 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1512 if (n_data_bytes == 0)
1514 *next0 = TCP_NEXT_DROP;
1518 /* Check if ACK can be delayed */
1519 if (tcp_can_delack (tc))
1521 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1522 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1526 *next0 = tcp_next_output (tc->c_is_ip4);
1527 tcp_make_ack (tc, b);
1535 tcp_header_t tcp_header;
1536 tcp_connection_t tcp_connection;
1540 format_tcp_rx_trace (u8 * s, va_list * args)
1542 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1543 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1544 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1545 uword indent = format_get_indent (s);
1547 s = format (s, "%U\n%U%U",
1548 format_tcp_header, &t->tcp_header, 128,
1549 format_white_space, indent,
1550 format_tcp_connection, &t->tcp_connection, 1);
1556 format_tcp_rx_trace_short (u8 * s, va_list * args)
1558 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1559 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1560 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1562 s = format (s, "%d -> %d (%U)",
1563 clib_net_to_host_u16 (t->tcp_header.src_port),
1564 clib_net_to_host_u16 (t->tcp_header.dst_port), format_tcp_state,
1565 t->tcp_connection.state);
1571 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1572 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1576 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1580 th0 = tcp_buffer_hdr (b0);
1582 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1586 tcp_established_inc_counter (vlib_main_t * vm, u8 is_ip4, u8 evt, u8 val)
1588 if (PREDICT_TRUE (!val))
1592 vlib_node_increment_counter (vm, tcp4_established_node.index, evt, val);
1594 vlib_node_increment_counter (vm, tcp6_established_node.index, evt, val);
1598 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1599 vlib_frame_t * from_frame, int is_ip4)
1601 u32 n_left_from, next_index, *from, *to_next;
1602 u32 my_thread_index = vm->thread_index, errors = 0;
1603 tcp_main_t *tm = vnet_get_tcp_main ();
1606 from = vlib_frame_vector_args (from_frame);
1607 n_left_from = from_frame->n_vectors;
1609 next_index = node->cached_next_index;
1611 while (n_left_from > 0)
1615 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1616 while (n_left_from > 0 && n_left_to_next > 0)
1620 tcp_header_t *th0 = 0;
1621 tcp_connection_t *tc0;
1622 u32 next0 = TCP_ESTABLISHED_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1629 n_left_to_next -= 1;
1631 b0 = vlib_get_buffer (vm, bi0);
1632 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1635 if (PREDICT_FALSE (tc0 == 0))
1637 error0 = TCP_ERROR_INVALID_CONNECTION;
1641 th0 = tcp_buffer_hdr (b0);
1642 is_fin = (th0->flags & TCP_FLAG_FIN) != 0;
1644 /* SYNs, FINs and data consume sequence numbers */
1645 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1646 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
1648 /* TODO header prediction fast path */
1650 /* 1-4: check SEQ, RST, SYN */
1651 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0)))
1653 error0 = TCP_ERROR_SEGMENT_INVALID;
1654 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0,
1655 vnet_buffer (b0)->tcp.seq_number,
1656 vnet_buffer (b0)->tcp.seq_end);
1660 /* 5: check the ACK field */
1661 if (tcp_rcv_ack (tc0, b0, th0, &next0, &error0))
1666 /* 6: check the URG bit TODO */
1668 /* 7: process the segment text */
1670 vlib_buffer_advance (b0, vnet_buffer (b0)->tcp.data_offset);
1671 error0 = tcp_segment_rcv (tm, tc0, b0,
1672 vnet_buffer (b0)->tcp.data_len, &next0);
1674 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
1675 * dangling reference. */
1677 /* 8: check the FIN bit */
1680 /* Enter CLOSE-WAIT and notify session. Don't send ACK, instead
1681 * wait for session to call close. To avoid lingering
1682 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1683 tc0->state = TCP_STATE_CLOSE_WAIT;
1684 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1685 stream_session_disconnect_notify (&tc0->connection);
1686 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1690 b0->error = node->errors[error0];
1691 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1693 tcp_rx_trace_t *t0 =
1694 vlib_add_trace (vm, node, b0, sizeof (*t0));
1695 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1698 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1699 n_left_to_next, bi0, next0);
1702 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1705 errors = session_manager_flush_enqueue_events (my_thread_index);
1706 tcp_established_inc_counter (vm, is_ip4, TCP_ERROR_EVENT_FIFO_FULL, errors);
1707 return from_frame->n_vectors;
1711 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1712 vlib_frame_t * from_frame)
1714 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1718 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1719 vlib_frame_t * from_frame)
1721 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1725 VLIB_REGISTER_NODE (tcp4_established_node) =
1727 .function = tcp4_established,
1728 .name = "tcp4-established",
1729 /* Takes a vector of packets. */
1730 .vector_size = sizeof (u32),
1731 .n_errors = TCP_N_ERROR,
1732 .error_strings = tcp_error_strings,
1733 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1736 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1737 foreach_tcp_state_next
1740 .format_trace = format_tcp_rx_trace_short,
1744 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
1747 VLIB_REGISTER_NODE (tcp6_established_node) =
1749 .function = tcp6_established,
1750 .name = "tcp6-established",
1751 /* Takes a vector of packets. */
1752 .vector_size = sizeof (u32),
1753 .n_errors = TCP_N_ERROR,
1754 .error_strings = tcp_error_strings,
1755 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1758 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1759 foreach_tcp_state_next
1762 .format_trace = format_tcp_rx_trace_short,
1767 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
1769 vlib_node_registration_t tcp4_syn_sent_node;
1770 vlib_node_registration_t tcp6_syn_sent_node;
1773 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1774 vlib_frame_t * from_frame, int is_ip4)
1776 tcp_main_t *tm = vnet_get_tcp_main ();
1777 u32 n_left_from, next_index, *from, *to_next;
1778 u32 my_thread_index = vm->thread_index, errors = 0;
1779 u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
1781 from = vlib_frame_vector_args (from_frame);
1782 n_left_from = from_frame->n_vectors;
1784 next_index = node->cached_next_index;
1786 while (n_left_from > 0)
1790 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1792 while (n_left_from > 0 && n_left_to_next > 0)
1794 u32 bi0, ack0, seq0;
1797 tcp_header_t *tcp0 = 0;
1798 tcp_connection_t *tc0;
1799 tcp_connection_t *new_tc0;
1800 u32 next0 = TCP_SYN_SENT_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1807 n_left_to_next -= 1;
1809 b0 = vlib_get_buffer (vm, bi0);
1811 tcp_half_open_connection_get (vnet_buffer (b0)->
1812 tcp.connection_index);
1814 ack0 = vnet_buffer (b0)->tcp.ack_number;
1815 seq0 = vnet_buffer (b0)->tcp.seq_number;
1816 tcp0 = tcp_buffer_hdr (b0);
1819 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
1822 /* SYNs, FINs and data consume sequence numbers */
1823 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
1824 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
1827 * 1. check the ACK bit
1831 * If the ACK bit is set
1832 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
1833 * the RST bit is set, if so drop the segment and return)
1834 * <SEQ=SEG.ACK><CTL=RST>
1835 * and discard the segment. Return.
1836 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
1840 if (ack0 <= tc0->iss || ack0 > tc0->snd_nxt)
1842 if (!tcp_rst (tcp0))
1843 tcp_send_reset (b0, is_ip4);
1848 /* Make sure ACK is valid */
1849 if (tc0->snd_una > ack0)
1854 * 2. check the RST bit
1859 /* If ACK is acceptable, signal client that peer is not
1860 * willing to accept connection and drop connection*/
1863 stream_session_connect_notify (&tc0->connection, sst,
1865 tcp_connection_cleanup (tc0);
1871 * 3. check the security and precedence (skipped)
1875 * 4. check the SYN bit
1878 /* No SYN flag. Drop. */
1879 if (!tcp_syn (tcp0))
1882 /* Stop connection establishment and retransmit timers */
1883 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
1884 tcp_timer_reset (tc0, TCP_TIMER_RETRANSMIT_SYN);
1886 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
1887 * current thread pool. */
1888 pool_get (tm->connections[my_thread_index], new_tc0);
1889 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
1891 new_tc0->c_thread_index = my_thread_index;
1892 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
1894 /* Cleanup half-open connection XXX lock */
1895 pool_put (tm->half_open_connections, tc0);
1897 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
1898 new_tc0->irs = seq0;
1901 if (tcp_options_parse (tcp0, &new_tc0->rcv_opts))
1904 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
1906 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
1907 new_tc0->tsval_recent_age = tcp_time_now ();
1910 if (tcp_opts_wscale (&new_tc0->rcv_opts))
1911 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
1913 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
1914 << new_tc0->snd_wscale;
1915 new_tc0->snd_wl1 = seq0;
1916 new_tc0->snd_wl2 = ack0;
1918 tcp_connection_init_vars (new_tc0);
1920 /* SYN-ACK: See if we can switch to ESTABLISHED state */
1923 /* Our SYN is ACKed: we have iss < ack = snd_una */
1925 /* TODO Dequeue acknowledged segments if we support Fast Open */
1926 new_tc0->snd_una = ack0;
1927 new_tc0->state = TCP_STATE_ESTABLISHED;
1929 /* Make sure las is initialized for the wnd computation */
1930 new_tc0->rcv_las = new_tc0->rcv_nxt;
1932 /* Notify app that we have connection. If session layer can't
1933 * allocate session send reset */
1934 if (stream_session_connect_notify (&new_tc0->connection, sst,
1937 tcp_connection_cleanup (new_tc0);
1938 tcp_send_reset (b0, is_ip4);
1942 /* Make sure after data segment processing ACK is sent */
1943 new_tc0->flags |= TCP_CONN_SNDACK;
1945 /* Update rtt with the syn-ack sample */
1946 new_tc0->bytes_acked = 1;
1947 tcp_update_rtt (new_tc0, vnet_buffer (b0)->tcp.ack_number);
1949 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
1952 new_tc0->state = TCP_STATE_SYN_RCVD;
1954 /* Notify app that we have connection */
1955 if (stream_session_connect_notify
1956 (&new_tc0->connection, sst, 0))
1958 tcp_connection_cleanup (new_tc0);
1959 tcp_send_reset (b0, is_ip4);
1965 tcp_make_synack (new_tc0, b0);
1966 next0 = tcp_next_output (is_ip4);
1971 /* Read data, if any */
1972 if (vnet_buffer (b0)->tcp.data_len)
1974 vlib_buffer_advance (b0, vnet_buffer (b0)->tcp.data_offset);
1975 error0 = tcp_segment_rcv (tm, new_tc0, b0,
1976 vnet_buffer (b0)->tcp.data_len,
1978 if (error0 == TCP_ERROR_PURE_ACK)
1979 error0 = TCP_ERROR_SYN_ACKS_RCVD;
1983 tcp_make_ack (new_tc0, b0);
1984 next0 = tcp_next_output (new_tc0->c_is_ip4);
1989 b0->error = error0 ? node->errors[error0] : 0;
1990 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1992 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1993 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
1994 clib_memcpy (&t0->tcp_connection, tc0,
1995 sizeof (t0->tcp_connection));
1998 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1999 n_left_to_next, bi0, next0);
2002 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2005 errors = session_manager_flush_enqueue_events (my_thread_index);
2009 vlib_node_increment_counter (vm, tcp4_established_node.index,
2010 TCP_ERROR_EVENT_FIFO_FULL, errors);
2012 vlib_node_increment_counter (vm, tcp6_established_node.index,
2013 TCP_ERROR_EVENT_FIFO_FULL, errors);
2016 return from_frame->n_vectors;
2020 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2021 vlib_frame_t * from_frame)
2023 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2027 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2028 vlib_frame_t * from_frame)
2030 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2034 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2036 .function = tcp4_syn_sent,
2037 .name = "tcp4-syn-sent",
2038 /* Takes a vector of packets. */
2039 .vector_size = sizeof (u32),
2040 .n_errors = TCP_N_ERROR,
2041 .error_strings = tcp_error_strings,
2042 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2045 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2046 foreach_tcp_state_next
2049 .format_trace = format_tcp_rx_trace_short,
2053 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2056 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2058 .function = tcp6_syn_sent_rcv,
2059 .name = "tcp6-syn-sent",
2060 /* Takes a vector of packets. */
2061 .vector_size = sizeof (u32),
2062 .n_errors = TCP_N_ERROR,
2063 .error_strings = tcp_error_strings,
2064 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2067 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2068 foreach_tcp_state_next
2071 .format_trace = format_tcp_rx_trace_short,
2075 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2077 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2078 * as per RFC793 p. 64
2081 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2082 vlib_frame_t * from_frame, int is_ip4)
2084 tcp_main_t *tm = vnet_get_tcp_main ();
2085 u32 n_left_from, next_index, *from, *to_next;
2086 u32 my_thread_index = vm->thread_index, errors = 0;
2088 from = vlib_frame_vector_args (from_frame);
2089 n_left_from = from_frame->n_vectors;
2091 next_index = node->cached_next_index;
2093 while (n_left_from > 0)
2097 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2099 while (n_left_from > 0 && n_left_to_next > 0)
2103 tcp_header_t *tcp0 = 0;
2104 tcp_connection_t *tc0;
2105 u32 next0 = TCP_RCV_PROCESS_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
2112 n_left_to_next -= 1;
2114 b0 = vlib_get_buffer (vm, bi0);
2115 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2117 if (PREDICT_FALSE (tc0 == 0))
2119 error0 = TCP_ERROR_INVALID_CONNECTION;
2123 tcp0 = tcp_buffer_hdr (b0);
2125 /* SYNs, FINs and data consume sequence numbers */
2126 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2127 + tcp_is_syn (tcp0) + tcp_is_fin (tcp0)
2128 + vnet_buffer (b0)->tcp.data_len;
2131 * Special treatment for CLOSED
2135 case TCP_STATE_CLOSED:
2141 * For all other states (except LISTEN)
2144 /* 1-4: check SEQ, RST, SYN */
2146 (tcp_segment_validate (vm, tc0, b0, tcp0, &next0)))
2148 error0 = TCP_ERROR_SEGMENT_INVALID;
2152 /* 5: check the ACK field */
2155 case TCP_STATE_SYN_RCVD:
2157 * If the segment acknowledgment is not acceptable, form a
2159 * <SEQ=SEG.ACK><CTL=RST>
2162 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2164 tcp_send_reset (b0, is_ip4);
2168 /* Update rtt and rto */
2169 tc0->bytes_acked = 1;
2170 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
2172 /* Switch state to ESTABLISHED */
2173 tc0->state = TCP_STATE_ESTABLISHED;
2175 /* Initialize session variables */
2176 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2177 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2178 << tc0->rcv_opts.wscale;
2179 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2180 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2181 stream_session_accept_notify (&tc0->connection);
2183 /* Reset SYN-ACK retransmit timer */
2184 tcp_retransmit_timer_reset (tc0);
2186 case TCP_STATE_ESTABLISHED:
2187 /* We can get packets in established state here because they
2188 * were enqueued before state change */
2189 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2193 case TCP_STATE_FIN_WAIT_1:
2194 /* In addition to the processing for the ESTABLISHED state, if
2195 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2196 * continue processing in that state. */
2197 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2200 /* If FIN is ACKed */
2201 if (tc0->snd_una == tc0->snd_una_max)
2203 ASSERT (tcp_fin (tcp0));
2204 tc0->state = TCP_STATE_FIN_WAIT_2;
2205 /* Stop all timers, 2MSL will be set lower */
2206 tcp_connection_timers_reset (tc0);
2209 case TCP_STATE_FIN_WAIT_2:
2210 /* In addition to the processing for the ESTABLISHED state, if
2211 * the retransmission queue is empty, the user's CLOSE can be
2212 * acknowledged ("ok") but do not delete the TCB. */
2213 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2215 /* check if rtx queue is empty and ack CLOSE TODO */
2217 case TCP_STATE_CLOSE_WAIT:
2218 /* Do the same processing as for the ESTABLISHED state. */
2219 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2222 case TCP_STATE_CLOSING:
2223 /* In addition to the processing for the ESTABLISHED state, if
2224 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2225 * otherwise ignore the segment. */
2226 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2229 /* XXX test that send queue empty */
2230 tc0->state = TCP_STATE_TIME_WAIT;
2234 case TCP_STATE_LAST_ACK:
2235 /* The only thing that [should] arrive in this state is an
2236 * acknowledgment of our FIN. If our FIN is now acknowledged,
2237 * delete the TCB, enter the CLOSED state, and return. */
2239 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2242 /* Apparently our FIN was lost */
2245 /* Don't "make" fin since that increments snd_nxt */
2250 tc0->state = TCP_STATE_CLOSED;
2252 /* Don't delete the connection/session yet. Instead, wait a
2253 * reasonable amount of time until the pipes are cleared. In
2254 * particular, this makes sure that we won't have dead sessions
2255 * when processing events on the tx path */
2256 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2258 /* Stop retransmit */
2259 tcp_retransmit_timer_reset (tc0);
2264 case TCP_STATE_TIME_WAIT:
2265 /* The only thing that can arrive in this state is a
2266 * retransmission of the remote FIN. Acknowledge it, and restart
2267 * the 2 MSL timeout. */
2269 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2272 tcp_make_ack (tc0, b0);
2273 tcp_timer_reset (tc0, TCP_TIMER_WAITCLOSE);
2274 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2283 /* 6: check the URG bit TODO */
2285 /* 7: process the segment text */
2288 case TCP_STATE_ESTABLISHED:
2289 case TCP_STATE_FIN_WAIT_1:
2290 case TCP_STATE_FIN_WAIT_2:
2291 vlib_buffer_advance (b0, vnet_buffer (b0)->tcp.data_offset);
2292 error0 = tcp_segment_rcv (tm, tc0, b0,
2293 vnet_buffer (b0)->tcp.data_len,
2296 case TCP_STATE_CLOSE_WAIT:
2297 case TCP_STATE_CLOSING:
2298 case TCP_STATE_LAST_ACK:
2299 case TCP_STATE_TIME_WAIT:
2300 /* This should not occur, since a FIN has been received from the
2301 * remote side. Ignore the segment text. */
2305 /* 8: check the FIN bit */
2306 if (!tcp_fin (tcp0))
2311 case TCP_STATE_ESTABLISHED:
2312 case TCP_STATE_SYN_RCVD:
2313 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2314 tcp_connection_timers_reset (tc0);
2315 tcp_make_fin (tc0, b0);
2316 next0 = tcp_next_output (tc0->c_is_ip4);
2317 stream_session_disconnect_notify (&tc0->connection);
2318 tc0->state = TCP_STATE_CLOSE_WAIT;
2320 case TCP_STATE_CLOSE_WAIT:
2321 case TCP_STATE_CLOSING:
2322 case TCP_STATE_LAST_ACK:
2325 case TCP_STATE_FIN_WAIT_1:
2326 tc0->state = TCP_STATE_TIME_WAIT;
2327 tcp_connection_timers_reset (tc0);
2328 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2330 case TCP_STATE_FIN_WAIT_2:
2331 /* Got FIN, send ACK! */
2332 tc0->state = TCP_STATE_TIME_WAIT;
2333 tcp_connection_timers_reset (tc0);
2334 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
2335 tcp_make_ack (tc0, b0);
2336 next0 = tcp_next_output (is_ip4);
2338 case TCP_STATE_TIME_WAIT:
2339 /* Remain in the TIME-WAIT state. Restart the 2 MSL time-wait
2342 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2345 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2348 b0->error = error0 ? node->errors[error0] : 0;
2350 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2352 tcp_rx_trace_t *t0 =
2353 vlib_add_trace (vm, node, b0, sizeof (*t0));
2354 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2357 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2358 n_left_to_next, bi0, next0);
2361 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2364 errors = session_manager_flush_enqueue_events (my_thread_index);
2368 vlib_node_increment_counter (vm, tcp4_established_node.index,
2369 TCP_ERROR_EVENT_FIFO_FULL, errors);
2371 vlib_node_increment_counter (vm, tcp6_established_node.index,
2372 TCP_ERROR_EVENT_FIFO_FULL, errors);
2375 return from_frame->n_vectors;
2379 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2380 vlib_frame_t * from_frame)
2382 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2386 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2387 vlib_frame_t * from_frame)
2389 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2393 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2395 .function = tcp4_rcv_process,
2396 .name = "tcp4-rcv-process",
2397 /* Takes a vector of packets. */
2398 .vector_size = sizeof (u32),
2399 .n_errors = TCP_N_ERROR,
2400 .error_strings = tcp_error_strings,
2401 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2404 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2405 foreach_tcp_state_next
2408 .format_trace = format_tcp_rx_trace_short,
2412 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2415 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2417 .function = tcp6_rcv_process,
2418 .name = "tcp6-rcv-process",
2419 /* Takes a vector of packets. */
2420 .vector_size = sizeof (u32),
2421 .n_errors = TCP_N_ERROR,
2422 .error_strings = tcp_error_strings,
2423 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2426 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2427 foreach_tcp_state_next
2430 .format_trace = format_tcp_rx_trace_short,
2434 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2436 vlib_node_registration_t tcp4_listen_node;
2437 vlib_node_registration_t tcp6_listen_node;
2440 * LISTEN state processing as per RFC 793 p. 65
2443 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2444 vlib_frame_t * from_frame, int is_ip4)
2446 u32 n_left_from, next_index, *from, *to_next;
2447 u32 my_thread_index = vm->thread_index;
2448 tcp_main_t *tm = vnet_get_tcp_main ();
2449 u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
2451 from = vlib_frame_vector_args (from_frame);
2452 n_left_from = from_frame->n_vectors;
2454 next_index = node->cached_next_index;
2456 while (n_left_from > 0)
2460 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2462 while (n_left_from > 0 && n_left_to_next > 0)
2467 tcp_header_t *th0 = 0;
2468 tcp_connection_t *lc0;
2471 tcp_connection_t *child0;
2472 u32 error0 = TCP_ERROR_SYNS_RCVD, next0 = TCP_LISTEN_NEXT_DROP;
2479 n_left_to_next -= 1;
2481 b0 = vlib_get_buffer (vm, bi0);
2482 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2486 ip40 = vlib_buffer_get_current (b0);
2487 th0 = ip4_next_header (ip40);
2491 ip60 = vlib_buffer_get_current (b0);
2492 th0 = ip6_next_header (ip60);
2495 /* Create child session. For syn-flood protection use filter */
2497 /* 1. first check for an RST: handled in dispatch */
2498 /* if (tcp_rst (th0))
2501 /* 2. second check for an ACK: handled in dispatch */
2502 /* if (tcp_ack (th0))
2504 tcp_send_reset (b0, is_ip4);
2508 /* 3. check for a SYN (did that already) */
2510 /* Create child session and send SYN-ACK */
2511 pool_get (tm->connections[my_thread_index], child0);
2512 memset (child0, 0, sizeof (*child0));
2514 child0->c_c_index = child0 - tm->connections[my_thread_index];
2515 child0->c_lcl_port = lc0->c_lcl_port;
2516 child0->c_rmt_port = th0->src_port;
2517 child0->c_is_ip4 = is_ip4;
2518 child0->c_thread_index = my_thread_index;
2519 child0->state = TCP_STATE_SYN_RCVD;
2523 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
2524 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
2528 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
2529 sizeof (ip6_address_t));
2530 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
2531 sizeof (ip6_address_t));
2534 if (stream_session_accept (&child0->connection, lc0->c_s_index, sst,
2537 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2541 if (tcp_options_parse (th0, &child0->rcv_opts))
2546 child0->irs = vnet_buffer (b0)->tcp.seq_number;
2547 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
2548 child0->rcv_las = child0->rcv_nxt;
2550 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
2551 * segments are used to initialize PAWS. */
2552 if (tcp_opts_tstamp (&child0->rcv_opts))
2554 child0->tsval_recent = child0->rcv_opts.tsval;
2555 child0->tsval_recent_age = tcp_time_now ();
2558 if (tcp_opts_wscale (&child0->rcv_opts))
2559 child0->snd_wscale = child0->rcv_opts.wscale;
2561 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
2562 << child0->snd_wscale;
2563 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2564 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2566 tcp_connection_init_vars (child0);
2568 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0);
2570 /* Reuse buffer to make syn-ack and send */
2571 tcp_make_synack (child0, b0);
2572 next0 = tcp_next_output (is_ip4);
2575 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2577 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2578 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2579 clib_memcpy (&t0->tcp_connection, lc0,
2580 sizeof (t0->tcp_connection));
2583 b0->error = node->errors[error0];
2585 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2586 n_left_to_next, bi0, next0);
2589 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2591 return from_frame->n_vectors;
2595 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2596 vlib_frame_t * from_frame)
2598 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2602 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2603 vlib_frame_t * from_frame)
2605 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2609 VLIB_REGISTER_NODE (tcp4_listen_node) =
2611 .function = tcp4_listen,
2612 .name = "tcp4-listen",
2613 /* Takes a vector of packets. */
2614 .vector_size = sizeof (u32),
2615 .n_errors = TCP_N_ERROR,
2616 .error_strings = tcp_error_strings,
2617 .n_next_nodes = TCP_LISTEN_N_NEXT,
2620 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2621 foreach_tcp_state_next
2624 .format_trace = format_tcp_rx_trace_short,
2628 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
2631 VLIB_REGISTER_NODE (tcp6_listen_node) =
2633 .function = tcp6_listen,
2634 .name = "tcp6-listen",
2635 /* Takes a vector of packets. */
2636 .vector_size = sizeof (u32),
2637 .n_errors = TCP_N_ERROR,
2638 .error_strings = tcp_error_strings,
2639 .n_next_nodes = TCP_LISTEN_N_NEXT,
2642 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2643 foreach_tcp_state_next
2646 .format_trace = format_tcp_rx_trace_short,
2650 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
2652 vlib_node_registration_t tcp4_input_node;
2653 vlib_node_registration_t tcp6_input_node;
2655 typedef enum _tcp_input_next
2657 TCP_INPUT_NEXT_DROP,
2658 TCP_INPUT_NEXT_LISTEN,
2659 TCP_INPUT_NEXT_RCV_PROCESS,
2660 TCP_INPUT_NEXT_SYN_SENT,
2661 TCP_INPUT_NEXT_ESTABLISHED,
2662 TCP_INPUT_NEXT_RESET,
2666 #define foreach_tcp4_input_next \
2667 _ (DROP, "error-drop") \
2668 _ (LISTEN, "tcp4-listen") \
2669 _ (RCV_PROCESS, "tcp4-rcv-process") \
2670 _ (SYN_SENT, "tcp4-syn-sent") \
2671 _ (ESTABLISHED, "tcp4-established") \
2672 _ (RESET, "tcp4-reset")
2674 #define foreach_tcp6_input_next \
2675 _ (DROP, "error-drop") \
2676 _ (LISTEN, "tcp6-listen") \
2677 _ (RCV_PROCESS, "tcp6-rcv-process") \
2678 _ (SYN_SENT, "tcp6-syn-sent") \
2679 _ (ESTABLISHED, "tcp6-established") \
2680 _ (RESET, "tcp6-reset")
2682 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
2685 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2686 vlib_frame_t * from_frame, int is_ip4)
2688 u32 n_left_from, next_index, *from, *to_next;
2689 u32 my_thread_index = vm->thread_index;
2690 tcp_main_t *tm = vnet_get_tcp_main ();
2692 from = vlib_frame_vector_args (from_frame);
2693 n_left_from = from_frame->n_vectors;
2695 next_index = node->cached_next_index;
2697 while (n_left_from > 0)
2701 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2703 while (n_left_from > 0 && n_left_to_next > 0)
2705 int n_advance_bytes0, n_data_bytes0;
2708 tcp_header_t *tcp0 = 0;
2709 tcp_connection_t *tc0;
2712 u32 error0 = TCP_ERROR_NO_LISTENER, next0 = TCP_INPUT_NEXT_DROP;
2720 n_left_to_next -= 1;
2722 b0 = vlib_get_buffer (vm, bi0);
2723 vnet_buffer (b0)->tcp.flags = 0;
2725 /* Checksum computed by ipx_local no need to compute again */
2729 ip40 = vlib_buffer_get_current (b0);
2730 tcp0 = ip4_next_header (ip40);
2731 n_advance_bytes0 = (ip4_header_bytes (ip40)
2732 + tcp_header_bytes (tcp0));
2733 n_data_bytes0 = clib_net_to_host_u16 (ip40->length)
2736 /* lookup session */
2738 (tcp_connection_t *)
2739 stream_session_lookup_transport4 (&ip40->dst_address,
2743 SESSION_TYPE_IP4_TCP,
2748 ip60 = vlib_buffer_get_current (b0);
2749 tcp0 = ip6_next_header (ip60);
2750 n_advance_bytes0 = tcp_header_bytes (tcp0);
2751 n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length)
2753 n_advance_bytes0 += sizeof (ip60[0]);
2756 (tcp_connection_t *)
2757 stream_session_lookup_transport6 (&ip60->src_address,
2761 SESSION_TYPE_IP6_TCP,
2766 if (PREDICT_FALSE (n_advance_bytes0 < 0))
2768 error0 = TCP_ERROR_LENGTH;
2772 /* Session exists */
2773 if (PREDICT_TRUE (0 != tc0))
2775 /* Save connection index */
2776 vnet_buffer (b0)->tcp.connection_index = tc0->c_c_index;
2777 vnet_buffer (b0)->tcp.seq_number =
2778 clib_net_to_host_u32 (tcp0->seq_number);
2779 vnet_buffer (b0)->tcp.ack_number =
2780 clib_net_to_host_u32 (tcp0->ack_number);
2782 vnet_buffer (b0)->tcp.hdr_offset = (u8 *) tcp0
2783 - (u8 *) vlib_buffer_get_current (b0);
2784 vnet_buffer (b0)->tcp.data_offset = n_advance_bytes0;
2785 vnet_buffer (b0)->tcp.data_len = n_data_bytes0;
2787 flags0 = tcp0->flags & filter_flags;
2788 next0 = tm->dispatch_table[tc0->state][flags0].next;
2789 error0 = tm->dispatch_table[tc0->state][flags0].error;
2791 if (PREDICT_FALSE (error0 == TCP_ERROR_DISPATCH
2792 || next0 == TCP_INPUT_NEXT_RESET))
2794 /* Overload tcp flags to store state */
2795 tcp_state_t state0 = tc0->state;
2796 vnet_buffer (b0)->tcp.flags = tc0->state;
2798 if (error0 == TCP_ERROR_DISPATCH)
2799 clib_warning ("disp error state %U flags %U",
2800 format_tcp_state, state0, format_tcp_flags,
2807 next0 = TCP_INPUT_NEXT_RESET;
2808 error0 = TCP_ERROR_NO_LISTENER;
2812 b0->error = error0 ? node->errors[error0] : 0;
2814 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2816 tcp_rx_trace_t *t0 =
2817 vlib_add_trace (vm, node, b0, sizeof (*t0));
2818 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2820 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2821 n_left_to_next, bi0, next0);
2824 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2827 return from_frame->n_vectors;
2831 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2832 vlib_frame_t * from_frame)
2834 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2838 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2839 vlib_frame_t * from_frame)
2841 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2845 VLIB_REGISTER_NODE (tcp4_input_node) =
2847 .function = tcp4_input,
2848 .name = "tcp4-input",
2849 /* Takes a vector of packets. */
2850 .vector_size = sizeof (u32),
2851 .n_errors = TCP_N_ERROR,
2852 .error_strings = tcp_error_strings,
2853 .n_next_nodes = TCP_INPUT_N_NEXT,
2856 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
2857 foreach_tcp4_input_next
2860 .format_buffer = format_tcp_header,
2861 .format_trace = format_tcp_rx_trace,
2865 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
2868 VLIB_REGISTER_NODE (tcp6_input_node) =
2870 .function = tcp6_input,
2871 .name = "tcp6-input",
2872 /* Takes a vector of packets. */
2873 .vector_size = sizeof (u32),
2874 .n_errors = TCP_N_ERROR,
2875 .error_strings = tcp_error_strings,
2876 .n_next_nodes = TCP_INPUT_N_NEXT,
2879 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
2880 foreach_tcp6_input_next
2883 .format_buffer = format_tcp_header,
2884 .format_trace = format_tcp_rx_trace,
2888 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
2891 tcp_dispatch_table_init (tcp_main_t * tm)
2894 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
2895 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
2897 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
2898 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
2901 #define _(t,f,n,e) \
2903 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
2904 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
2907 /* SYNs for new connections -> tcp-listen. */
2908 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
2909 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
2910 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_NONE);
2911 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
2913 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
2914 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2915 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2916 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2917 /* SYN-ACK for a SYN */
2918 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
2920 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
2921 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
2922 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
2924 /* ACK for for established connection -> tcp-established. */
2925 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2926 /* FIN for for established connection -> tcp-established. */
2927 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2928 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
2930 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2931 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
2933 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2934 /* ACK or FIN-ACK to our FIN */
2935 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2936 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
2938 /* FIN in reply to our FIN from the other side */
2939 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2940 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2941 /* FIN confirming that the peer (app) has closed */
2942 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2943 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2944 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
2946 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2947 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
2949 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2950 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2951 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
2953 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2954 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2955 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
2957 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_CONNECTION_CLOSED);
2958 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
2959 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
2960 TCP_ERROR_CONNECTION_CLOSED);
2965 tcp_input_init (vlib_main_t * vm)
2967 clib_error_t *error = 0;
2968 tcp_main_t *tm = vnet_get_tcp_main ();
2970 if ((error = vlib_call_init_function (vm, tcp_init)))
2973 /* Initialize dispatch table. */
2974 tcp_dispatch_table_init (tm);
2979 VLIB_INIT_FUNCTION (tcp_input_init);
2982 * fd.io coding-style-patch-verification: ON
2985 * eval: (c-set-style "gnu")