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 + 8 * j));
210 b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 8 * 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 /* Poison the entry */
545 memset (hole, 0xfe, sizeof (*hole));
547 pool_put (sb->holes, hole);
550 sack_scoreboard_hole_t *
551 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
554 sack_scoreboard_hole_t *hole, *next, *prev;
557 pool_get (sb->holes, hole);
558 memset (hole, 0, sizeof (*hole));
562 hole_index = scoreboard_hole_index (sb, hole);
564 prev = scoreboard_get_hole (sb, prev_index);
567 hole->prev = prev_index;
568 hole->next = prev->next;
570 if ((next = scoreboard_next_hole (sb, hole)))
571 next->prev = hole_index;
573 sb->tail = hole_index;
575 prev->next = hole_index;
579 sb->head = hole_index;
580 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
581 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
588 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
590 sack_scoreboard_hole_t *hole, *prev;
591 u32 bytes = 0, blks = 0;
594 sb->sacked_bytes = 0;
595 hole = scoreboard_last_hole (sb);
599 if (seq_gt (sb->high_sacked, hole->end))
601 bytes = sb->high_sacked - hole->end;
605 while ((prev = scoreboard_prev_hole (sb, hole))
606 && (bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
607 && blks < TCP_DUPACK_THRESHOLD))
609 bytes += hole->start - prev->end;
616 sb->lost_bytes += scoreboard_hole_bytes (hole);
619 hole = scoreboard_prev_hole (sb, hole);
621 bytes += prev->start - hole->end;
623 sb->sacked_bytes = bytes;
627 * Figure out the next hole to retransmit
629 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
631 sack_scoreboard_hole_t *
632 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
633 sack_scoreboard_hole_t * start,
635 u8 * can_rescue, u8 * snd_limited)
637 sack_scoreboard_hole_t *hole = 0;
639 hole = start ? start : scoreboard_first_hole (sb);
640 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
641 hole = scoreboard_next_hole (sb, hole);
643 /* Nothing, return */
646 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
650 /* Rule (1): if higher than rxt, less than high_sacked and lost */
651 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
653 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
657 /* Rule (2): output takes care of transmitting new data */
658 if (!have_sent_1_smss)
661 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
663 /* Rule (3): if hole not lost */
664 else if (seq_lt (hole->start, sb->high_sacked))
667 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
669 /* Rule (4): if hole beyond high_sacked */
672 ASSERT (seq_geq (hole->start, sb->high_sacked));
675 /* HighRxt MUST NOT be updated */
680 if (hole && seq_lt (sb->high_rxt, hole->start))
681 sb->high_rxt = hole->start;
687 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 seq)
689 sack_scoreboard_hole_t *hole;
690 hole = scoreboard_first_hole (sb);
693 seq = seq_gt (seq, hole->start) ? seq : hole->start;
694 sb->cur_rxt_hole = sb->head;
700 * Test that scoreboard is sane after recovery
702 * Returns 1 if scoreboard is empty or if first hole beyond
706 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
708 sack_scoreboard_hole_t *hole;
709 hole = scoreboard_first_hole (&tc->sack_sb);
710 return (!hole || seq_geq (hole->start, tc->snd_una));
714 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
716 sack_scoreboard_t *sb = &tc->sack_sb;
717 sack_block_t *blk, tmp;
718 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
719 u32 blk_index = 0, old_sacked_bytes, hole_index;
722 sb->last_sacked_bytes = 0;
724 old_sacked_bytes = sb->sacked_bytes;
725 sb->last_bytes_delivered = 0;
727 if (!tcp_opts_sack (&tc->rcv_opts)
728 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
731 /* Remove invalid blocks */
732 blk = tc->rcv_opts.sacks;
733 while (blk < vec_end (tc->rcv_opts.sacks))
735 if (seq_lt (blk->start, blk->end)
736 && seq_gt (blk->start, tc->snd_una)
737 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_una_max))
742 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
745 /* Add block for cumulative ack */
746 if (seq_gt (ack, tc->snd_una))
748 tmp.start = tc->snd_una;
750 vec_add1 (tc->rcv_opts.sacks, tmp);
753 if (vec_len (tc->rcv_opts.sacks) == 0)
756 tcp_scoreboard_trace_add (tc, ack);
758 /* Make sure blocks are ordered */
759 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
760 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
761 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
763 tmp = tc->rcv_opts.sacks[i];
764 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
765 tc->rcv_opts.sacks[j] = tmp;
768 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
770 /* If no holes, insert the first that covers all outstanding bytes */
771 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
772 tc->snd_una, tc->snd_una_max);
773 sb->tail = scoreboard_hole_index (sb, last_hole);
774 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
775 sb->high_sacked = tmp.end;
779 /* If we have holes but snd_una_max is beyond the last hole, update
781 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
782 last_hole = scoreboard_last_hole (sb);
783 if (seq_gt (tc->snd_una_max, last_hole->end))
785 if (seq_geq (last_hole->start, sb->high_sacked))
787 last_hole->end = tc->snd_una_max;
789 /* New hole after high sacked block */
790 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
792 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
796 /* Keep track of max byte sacked for when the last hole
798 if (seq_gt (tmp.end, sb->high_sacked))
799 sb->high_sacked = tmp.end;
802 /* Walk the holes with the SACK blocks */
803 hole = pool_elt_at_index (sb->holes, sb->head);
804 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
806 blk = &tc->rcv_opts.sacks[blk_index];
807 if (seq_leq (blk->start, hole->start))
809 /* Block covers hole. Remove hole */
810 if (seq_geq (blk->end, hole->end))
812 next_hole = scoreboard_next_hole (sb, hole);
814 /* Byte accounting: snd_una needs to be advanced */
819 if (seq_lt (ack, next_hole->start))
820 sb->snd_una_adv = next_hole->start - ack;
821 sb->last_bytes_delivered +=
822 next_hole->start - hole->end;
826 ASSERT (seq_geq (sb->high_sacked, ack));
827 sb->snd_una_adv = sb->high_sacked - ack;
828 sb->last_bytes_delivered += sb->high_sacked - hole->end;
832 scoreboard_remove_hole (sb, hole);
835 /* Partial 'head' overlap */
838 if (seq_gt (blk->end, hole->start))
840 hole->start = blk->end;
847 /* Hole must be split */
848 if (seq_lt (blk->end, hole->end))
850 hole_index = scoreboard_hole_index (sb, hole);
851 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
854 /* Pool might've moved */
855 hole = scoreboard_get_hole (sb, hole_index);
856 hole->end = blk->start;
858 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
860 else if (seq_lt (blk->start, hole->end))
862 hole->end = blk->start;
864 hole = scoreboard_next_hole (sb, hole);
868 scoreboard_update_bytes (tc, sb);
869 sb->last_sacked_bytes = sb->sacked_bytes
870 - (old_sacked_bytes - sb->last_bytes_delivered);
871 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes);
872 ASSERT (sb->sacked_bytes == 0
873 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
874 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
875 - seq_max (tc->snd_una, ack));
876 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
877 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
881 * Try to update snd_wnd based on feedback received from peer.
883 * If successful, and new window is 'effectively' 0, activate persist
887 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
889 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
890 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
891 if (seq_lt (tc->snd_wl1, seq)
892 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
894 tc->snd_wnd = snd_wnd;
897 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
899 if (tc->snd_wnd < tc->snd_mss)
901 /* Set persist timer if not set and we just got 0 wnd */
902 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
903 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
904 tcp_persist_timer_set (tc);
908 tcp_persist_timer_reset (tc);
909 if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
919 tcp_cc_init_congestion (tcp_connection_t * tc)
921 tcp_fastrecovery_on (tc);
922 tc->snd_congestion = tc->snd_una_max;
923 tc->cc_algo->congestion (tc);
924 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
928 tcp_cc_recovery_exit (tcp_connection_t * tc)
934 tcp_recovery_off (tc);
938 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
940 tc->cc_algo->recovered (tc);
941 tc->snd_rxt_bytes = 0;
943 tcp_fastrecovery_off (tc);
944 tcp_fastrecovery_1_smss_off (tc);
948 tcp_cc_congestion_undo (tcp_connection_t * tc)
950 tc->cwnd = tc->prev_cwnd;
951 tc->ssthresh = tc->prev_ssthresh;
952 tc->snd_nxt = tc->snd_una_max;
954 if (tcp_in_recovery (tc))
955 tcp_cc_recovery_exit (tc);
956 ASSERT (tc->rto_boff == 0);
957 /* TODO extend for fastrecovery */
961 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
963 return (tcp_in_recovery (tc)
965 && tcp_opts_tstamp (&tc->rcv_opts)
966 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
970 tcp_cc_recover (tcp_connection_t * tc)
972 ASSERT (tcp_in_cong_recovery (tc));
973 if (tcp_cc_is_spurious_retransmit (tc))
975 tcp_cc_congestion_undo (tc);
979 if (tcp_in_recovery (tc))
980 tcp_cc_recovery_exit (tc);
981 else if (tcp_in_fastrecovery (tc))
982 tcp_cc_fastrecovery_exit (tc);
984 ASSERT (tc->rto_boff == 0);
985 ASSERT (!tcp_in_cong_recovery (tc));
986 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
987 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
992 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
994 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
996 /* Congestion avoidance */
997 tc->cc_algo->rcv_ack (tc);
998 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1000 /* If a cumulative ack, make sure dupacks is 0 */
1001 tc->rcv_dupacks = 0;
1003 /* When dupacks hits the threshold we only enter fast retransmit if
1004 * cumulative ack covers more than snd_congestion. Should snd_una
1005 * wrap this test may fail under otherwise valid circumstances.
1006 * Therefore, proactively update snd_congestion when wrap detected. */
1008 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1009 && seq_gt (tc->snd_congestion, tc->snd_una)))
1010 tc->snd_congestion = tc->snd_una - 1;
1014 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1016 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1020 tcp_should_fastrecover (tcp_connection_t * tc)
1022 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1023 || tcp_should_fastrecover_sack (tc));
1027 * One function to rule them all ... and in the darkness bind them
1030 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1035 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1036 * it account for the bytes that left the network.
1040 ASSERT (tc->snd_una != tc->snd_una_max
1041 || tc->sack_sb.last_sacked_bytes);
1045 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1047 ASSERT (tcp_in_fastrecovery (tc));
1048 /* Pure duplicate ack. If some data got acked, it's handled lower */
1049 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1052 else if (tcp_should_fastrecover (tc))
1054 /* Things are already bad */
1055 if (tcp_in_cong_recovery (tc))
1057 tc->rcv_dupacks = 0;
1058 goto partial_ack_test;
1061 /* If of of the two conditions lower hold, reset dupacks because
1062 * we're probably after timeout (RFC6582 heuristics).
1063 * If Cumulative ack does not cover more than congestion threshold,
1065 * 1) The following doesn't hold: The congestion window is greater
1066 * than SMSS bytes and the difference between highest_ack
1067 * and prev_highest_ack is at most 4*SMSS bytes
1068 * 2) Echoed timestamp in the last non-dup ack does not equal the
1071 if (seq_leq (tc->snd_una, tc->snd_congestion)
1072 && ((!(tc->cwnd > tc->snd_mss
1073 && tc->bytes_acked <= 4 * tc->snd_mss))
1074 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1076 tc->rcv_dupacks = 0;
1080 tcp_cc_init_congestion (tc);
1081 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1083 /* The first segment MUST be retransmitted */
1084 tcp_retransmit_first_unacked (tc);
1086 /* Post retransmit update cwnd to ssthresh and account for the
1087 * three segments that have left the network and should've been
1088 * buffered at the receiver XXX */
1089 tc->cwnd = tc->ssthresh + tc->rcv_dupacks * tc->snd_mss;
1090 ASSERT (tc->cwnd >= tc->snd_mss);
1092 /* If cwnd allows, send more data */
1093 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1095 scoreboard_init_high_rxt (&tc->sack_sb,
1096 tc->snd_una + tc->snd_mss);
1097 tcp_fast_retransmit_sack (tc);
1101 tcp_fast_retransmit_no_sack (tc);
1106 else if (!tc->bytes_acked
1107 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1109 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1118 if (!tc->bytes_acked)
1123 * Legitimate ACK. 1) See if we can exit recovery
1125 /* XXX limit this only to first partial ack? */
1126 tcp_retransmit_timer_update (tc);
1128 if (seq_geq (tc->snd_una, tc->snd_congestion))
1130 /* If spurious return, we've already updated everything */
1131 if (tcp_cc_recover (tc))
1133 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1137 tc->snd_nxt = tc->snd_una_max;
1139 /* Treat as congestion avoidance ack */
1140 tc->cc_algo->rcv_ack (tc);
1141 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1146 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1148 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1150 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1151 * reset dupacks to 0 */
1152 tc->rcv_dupacks = 0;
1154 tcp_retransmit_first_unacked (tc);
1156 /* Post RTO timeout don't try anything fancy */
1157 if (tcp_in_recovery (tc))
1160 /* Remove retransmitted bytes that have been delivered */
1161 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1162 >= tc->sack_sb.last_bytes_delivered);
1164 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1166 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1167 * remove sacked bytes delivered */
1168 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1169 - tc->sack_sb.last_bytes_delivered;
1170 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1171 tc->snd_rxt_bytes -= rxt_delivered;
1175 /* Either all retransmitted holes have been acked, or we're
1176 * "in the blind" and retransmitting segment by segment */
1177 tc->snd_rxt_bytes = 0;
1180 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1183 * Since this was a partial ack, try to retransmit some more data
1185 tcp_fast_retransmit (tc);
1189 tcp_cc_init (tcp_connection_t * tc)
1191 tc->cc_algo = tcp_cc_algo_get (TCP_CC_NEWRENO);
1192 tc->cc_algo->init (tc);
1196 * Process incoming ACK
1199 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
1200 tcp_header_t * th, u32 * next, u32 * error)
1202 u32 prev_snd_wnd, prev_snd_una;
1205 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1207 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1208 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1210 /* If we have outstanding data and this is within the window, accept it,
1211 * probably retransmit has timed out. Otherwise ACK segment and then
1213 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1215 tcp_make_ack (tc, b);
1216 *next = tcp_next_output (tc->c_is_ip4);
1217 *error = TCP_ERROR_ACK_INVALID;
1218 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1219 vnet_buffer (b)->tcp.ack_number);
1223 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1224 vnet_buffer (b)->tcp.ack_number);
1226 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1227 *error = TCP_ERROR_ACK_FUTURE;
1230 /* If old ACK, probably it's an old dupack */
1231 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1233 *error = TCP_ERROR_ACK_OLD;
1234 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1235 vnet_buffer (b)->tcp.ack_number);
1236 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1238 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc);
1239 tcp_cc_handle_event (tc, 1);
1241 /* Don't drop yet */
1246 * Looks okay, process feedback
1249 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1251 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1252 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1254 prev_snd_wnd = tc->snd_wnd;
1255 prev_snd_una = tc->snd_una;
1256 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1257 vnet_buffer (b)->tcp.ack_number,
1258 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1259 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1260 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1261 tcp_validate_txf_size (tc, tc->bytes_acked);
1263 if (tc->bytes_acked)
1264 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
1267 * Check if we have congestion event
1270 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1272 tcp_cc_handle_event (tc, is_dack);
1273 *error = TCP_ERROR_ACK_DUP;
1274 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1275 return vnet_buffer (b)->tcp.data_len ? 0 : -1;
1279 * Update congestion control (slow start/congestion avoidance)
1281 tcp_cc_update (tc, b);
1287 tcp_sack_vector_is_sane (sack_block_t * sacks)
1290 for (i = 1; i < vec_len (sacks); i++)
1292 if (sacks[i - 1].end == sacks[i].start)
1299 * Build SACK list as per RFC2018.
1301 * Makes sure the first block contains the segment that generated the current
1302 * ACK and the following ones are the ones most recently reported in SACK
1305 * @param tc TCP connection for which the SACK list is updated
1306 * @param start Start sequence number of the newest SACK block
1307 * @param end End sequence of the newest SACK block
1310 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1312 sack_block_t *new_list = 0, *block = 0;
1315 /* If the first segment is ooo add it to the list. Last write might've moved
1316 * rcv_nxt over the first segment. */
1317 if (seq_lt (tc->rcv_nxt, start))
1319 vec_add2 (new_list, block, 1);
1320 block->start = start;
1324 /* Find the blocks still worth keeping. */
1325 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1327 /* Discard if rcv_nxt advanced beyond current block */
1328 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1331 /* Merge or drop if segment overlapped by the new segment */
1332 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1333 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1335 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1336 new_list[0].start = tc->snd_sacks[i].start;
1337 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1338 new_list[0].end = tc->snd_sacks[i].end;
1342 /* Save to new SACK list if we have space. */
1343 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1345 vec_add1 (new_list, tc->snd_sacks[i]);
1349 clib_warning ("sack discarded");
1353 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1355 /* Replace old vector with new one */
1356 vec_free (tc->snd_sacks);
1357 tc->snd_sacks = new_list;
1359 /* Segments should not 'touch' */
1360 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1363 /** Enqueue data for delivery to application */
1365 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1370 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1372 /* Pure ACK. Update rcv_nxt and be done. */
1373 if (PREDICT_FALSE (data_len == 0))
1375 return TCP_ERROR_PURE_ACK;
1378 written = stream_session_enqueue_data (&tc->connection, b, 0,
1379 1 /* queue event */ , 1);
1381 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1383 /* Update rcv_nxt */
1384 if (PREDICT_TRUE (written == data_len))
1386 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end;
1388 /* If more data written than expected, account for out-of-order bytes. */
1389 else if (written > data_len)
1391 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end + written - data_len;
1393 /* Send ACK confirming the update */
1394 tc->flags |= TCP_CONN_SNDACK;
1396 else if (written > 0)
1398 /* We've written something but FIFO is probably full now */
1399 tc->rcv_nxt += written;
1401 /* Depending on how fast the app is, all remaining buffers in burst will
1402 * not be enqueued. Inform peer */
1403 tc->flags |= TCP_CONN_SNDACK;
1405 return TCP_ERROR_PARTIALLY_ENQUEUED;
1409 tc->flags |= TCP_CONN_SNDACK;
1410 return TCP_ERROR_FIFO_FULL;
1413 /* Update SACK list if need be */
1414 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1416 /* Remove SACK blocks that have been delivered */
1417 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1420 return TCP_ERROR_ENQUEUED;
1423 /** Enqueue out-of-order data */
1425 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1428 stream_session_t *s0;
1431 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1433 /* Pure ACK. Do nothing */
1434 if (PREDICT_FALSE (data_len == 0))
1436 return TCP_ERROR_PURE_ACK;
1439 /* Enqueue out-of-order data with relative offset */
1440 rv = stream_session_enqueue_data (&tc->connection, b,
1441 vnet_buffer (b)->tcp.seq_number -
1442 tc->rcv_nxt, 0 /* queue event */ , 0);
1444 /* Nothing written */
1447 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1448 return TCP_ERROR_FIFO_FULL;
1451 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1453 /* Update SACK list if in use */
1454 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1456 ooo_segment_t *newest;
1459 s0 = stream_session_get (tc->c_s_index, tc->c_thread_index);
1461 /* Get the newest segment from the fifo */
1462 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1465 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1466 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1467 start = tc->rcv_nxt + offset;
1468 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1469 tcp_update_sack_list (tc, start, end);
1470 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1474 return TCP_ERROR_ENQUEUED;
1478 * Check if ACK could be delayed. If ack can be delayed, it should return
1479 * true for a full frame. If we're always acking return 0.
1482 tcp_can_delack (tcp_connection_t * tc)
1484 /* Send ack if ... */
1486 /* just sent a rcv wnd 0 */
1487 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1488 /* constrained to send ack */
1489 || (tc->flags & TCP_CONN_SNDACK) != 0
1490 /* we're almost out of tx wnd */
1491 || tcp_available_snd_space (tc) < 4 * tc->snd_mss)
1498 tcp_segment_rcv (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b,
1499 u16 n_data_bytes, u32 * next0)
1501 u32 error = 0, n_bytes_to_drop;
1503 /* Handle out-of-order data */
1504 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1506 /* Old sequence numbers allowed through because they overlapped
1508 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1510 error = TCP_ERROR_SEGMENT_OLD;
1511 *next0 = TCP_NEXT_DROP;
1513 /* Completely in the past (possible retransmit) */
1514 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1517 /* Chop off the bytes in the past */
1518 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1519 n_data_bytes -= n_bytes_to_drop;
1520 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1521 vlib_buffer_advance (b, n_bytes_to_drop);
1526 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1528 /* N.B. Should not filter burst of dupacks. Two issues 1) dupacks open
1529 * cwnd on remote peer when congested 2) acks leaving should have the
1530 * latest rcv_wnd since the burst may eaten up all of it, so only the
1531 * old ones could be filtered.
1534 /* RFC2581: Send DUPACK for fast retransmit */
1535 tcp_make_ack (tc, b);
1536 *next0 = tcp_next_output (tc->c_is_ip4);
1538 /* Mark as DUPACK. We may filter these in output if
1539 * the burst fills the holes. */
1541 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1543 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc);
1549 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1550 * segments can be enqueued after fifo tail offset changes. */
1551 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1553 if (n_data_bytes == 0)
1555 *next0 = TCP_NEXT_DROP;
1559 /* Check if ACK can be delayed */
1560 if (tcp_can_delack (tc))
1562 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1563 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1567 *next0 = tcp_next_output (tc->c_is_ip4);
1568 tcp_make_ack (tc, b);
1576 tcp_header_t tcp_header;
1577 tcp_connection_t tcp_connection;
1581 format_tcp_rx_trace (u8 * s, va_list * args)
1583 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1584 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1585 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1586 uword indent = format_get_indent (s);
1588 s = format (s, "%U\n%U%U",
1589 format_tcp_header, &t->tcp_header, 128,
1590 format_white_space, indent,
1591 format_tcp_connection, &t->tcp_connection, 1);
1597 format_tcp_rx_trace_short (u8 * s, va_list * args)
1599 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1600 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1601 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1603 s = format (s, "%d -> %d (%U)",
1604 clib_net_to_host_u16 (t->tcp_header.src_port),
1605 clib_net_to_host_u16 (t->tcp_header.dst_port), format_tcp_state,
1606 t->tcp_connection.state);
1612 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1613 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1617 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1621 th0 = tcp_buffer_hdr (b0);
1623 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1627 tcp_established_inc_counter (vlib_main_t * vm, u8 is_ip4, u8 evt, u8 val)
1629 if (PREDICT_TRUE (!val))
1633 vlib_node_increment_counter (vm, tcp4_established_node.index, evt, val);
1635 vlib_node_increment_counter (vm, tcp6_established_node.index, evt, val);
1639 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1640 vlib_frame_t * from_frame, int is_ip4)
1642 u32 n_left_from, next_index, *from, *to_next;
1643 u32 my_thread_index = vm->thread_index, errors = 0;
1644 tcp_main_t *tm = vnet_get_tcp_main ();
1647 from = vlib_frame_vector_args (from_frame);
1648 n_left_from = from_frame->n_vectors;
1650 next_index = node->cached_next_index;
1652 while (n_left_from > 0)
1656 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1657 while (n_left_from > 0 && n_left_to_next > 0)
1661 tcp_header_t *th0 = 0;
1662 tcp_connection_t *tc0;
1663 u32 next0 = TCP_ESTABLISHED_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1670 n_left_to_next -= 1;
1672 b0 = vlib_get_buffer (vm, bi0);
1673 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1676 if (PREDICT_FALSE (tc0 == 0))
1678 error0 = TCP_ERROR_INVALID_CONNECTION;
1682 th0 = tcp_buffer_hdr (b0);
1683 is_fin = (th0->flags & TCP_FLAG_FIN) != 0;
1685 /* SYNs, FINs and data consume sequence numbers */
1686 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1687 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
1689 /* TODO header prediction fast path */
1691 /* 1-4: check SEQ, RST, SYN */
1692 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0)))
1694 error0 = TCP_ERROR_SEGMENT_INVALID;
1695 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0,
1696 vnet_buffer (b0)->tcp.seq_number,
1697 vnet_buffer (b0)->tcp.seq_end);
1701 /* 5: check the ACK field */
1702 if (tcp_rcv_ack (tc0, b0, th0, &next0, &error0))
1707 /* 6: check the URG bit TODO */
1709 /* 7: process the segment text */
1711 vlib_buffer_advance (b0, vnet_buffer (b0)->tcp.data_offset);
1712 error0 = tcp_segment_rcv (tm, tc0, b0,
1713 vnet_buffer (b0)->tcp.data_len, &next0);
1715 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
1716 * dangling reference. */
1718 /* 8: check the FIN bit */
1721 /* Enter CLOSE-WAIT and notify session. Don't send ACK, instead
1722 * wait for session to call close. To avoid lingering
1723 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1724 tc0->state = TCP_STATE_CLOSE_WAIT;
1725 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1726 stream_session_disconnect_notify (&tc0->connection);
1727 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1731 b0->error = node->errors[error0];
1732 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1734 tcp_rx_trace_t *t0 =
1735 vlib_add_trace (vm, node, b0, sizeof (*t0));
1736 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1739 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1740 n_left_to_next, bi0, next0);
1743 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1746 errors = session_manager_flush_enqueue_events (my_thread_index);
1747 tcp_established_inc_counter (vm, is_ip4, TCP_ERROR_EVENT_FIFO_FULL, errors);
1748 return from_frame->n_vectors;
1752 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1753 vlib_frame_t * from_frame)
1755 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1759 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1760 vlib_frame_t * from_frame)
1762 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1766 VLIB_REGISTER_NODE (tcp4_established_node) =
1768 .function = tcp4_established,
1769 .name = "tcp4-established",
1770 /* Takes a vector of packets. */
1771 .vector_size = sizeof (u32),
1772 .n_errors = TCP_N_ERROR,
1773 .error_strings = tcp_error_strings,
1774 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1777 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1778 foreach_tcp_state_next
1781 .format_trace = format_tcp_rx_trace_short,
1785 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
1788 VLIB_REGISTER_NODE (tcp6_established_node) =
1790 .function = tcp6_established,
1791 .name = "tcp6-established",
1792 /* Takes a vector of packets. */
1793 .vector_size = sizeof (u32),
1794 .n_errors = TCP_N_ERROR,
1795 .error_strings = tcp_error_strings,
1796 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1799 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1800 foreach_tcp_state_next
1803 .format_trace = format_tcp_rx_trace_short,
1808 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
1810 vlib_node_registration_t tcp4_syn_sent_node;
1811 vlib_node_registration_t tcp6_syn_sent_node;
1814 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1815 vlib_frame_t * from_frame, int is_ip4)
1817 tcp_main_t *tm = vnet_get_tcp_main ();
1818 u32 n_left_from, next_index, *from, *to_next;
1819 u32 my_thread_index = vm->thread_index, errors = 0;
1820 u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
1822 from = vlib_frame_vector_args (from_frame);
1823 n_left_from = from_frame->n_vectors;
1825 next_index = node->cached_next_index;
1827 while (n_left_from > 0)
1831 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1833 while (n_left_from > 0 && n_left_to_next > 0)
1835 u32 bi0, ack0, seq0;
1838 tcp_header_t *tcp0 = 0;
1839 tcp_connection_t *tc0;
1840 tcp_connection_t *new_tc0;
1841 u32 next0 = TCP_SYN_SENT_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1848 n_left_to_next -= 1;
1850 b0 = vlib_get_buffer (vm, bi0);
1852 tcp_half_open_connection_get (vnet_buffer (b0)->
1853 tcp.connection_index);
1855 ack0 = vnet_buffer (b0)->tcp.ack_number;
1856 seq0 = vnet_buffer (b0)->tcp.seq_number;
1857 tcp0 = tcp_buffer_hdr (b0);
1860 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
1863 /* SYNs, FINs and data consume sequence numbers */
1864 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
1865 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
1868 * 1. check the ACK bit
1872 * If the ACK bit is set
1873 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
1874 * the RST bit is set, if so drop the segment and return)
1875 * <SEQ=SEG.ACK><CTL=RST>
1876 * and discard the segment. Return.
1877 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
1881 if (ack0 <= tc0->iss || ack0 > tc0->snd_nxt)
1883 if (!tcp_rst (tcp0))
1884 tcp_send_reset (b0, is_ip4);
1889 /* Make sure ACK is valid */
1890 if (tc0->snd_una > ack0)
1895 * 2. check the RST bit
1900 /* If ACK is acceptable, signal client that peer is not
1901 * willing to accept connection and drop connection*/
1904 stream_session_connect_notify (&tc0->connection, sst,
1906 tcp_connection_cleanup (tc0);
1912 * 3. check the security and precedence (skipped)
1916 * 4. check the SYN bit
1919 /* No SYN flag. Drop. */
1920 if (!tcp_syn (tcp0))
1923 /* Stop connection establishment and retransmit timers */
1924 tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
1925 tcp_timer_reset (tc0, TCP_TIMER_RETRANSMIT_SYN);
1927 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
1928 * current thread pool. */
1929 pool_get (tm->connections[my_thread_index], new_tc0);
1930 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
1932 new_tc0->c_thread_index = my_thread_index;
1933 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
1935 /* Cleanup half-open connection XXX lock */
1936 pool_put (tm->half_open_connections, tc0);
1938 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
1939 new_tc0->irs = seq0;
1942 if (tcp_options_parse (tcp0, &new_tc0->rcv_opts))
1945 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
1947 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
1948 new_tc0->tsval_recent_age = tcp_time_now ();
1951 if (tcp_opts_wscale (&new_tc0->rcv_opts))
1952 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
1954 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
1955 << new_tc0->snd_wscale;
1956 new_tc0->snd_wl1 = seq0;
1957 new_tc0->snd_wl2 = ack0;
1959 tcp_connection_init_vars (new_tc0);
1961 /* SYN-ACK: See if we can switch to ESTABLISHED state */
1964 /* Our SYN is ACKed: we have iss < ack = snd_una */
1966 /* TODO Dequeue acknowledged segments if we support Fast Open */
1967 new_tc0->snd_una = ack0;
1968 new_tc0->state = TCP_STATE_ESTABLISHED;
1970 /* Make sure las is initialized for the wnd computation */
1971 new_tc0->rcv_las = new_tc0->rcv_nxt;
1973 /* Notify app that we have connection. If session layer can't
1974 * allocate session send reset */
1975 if (stream_session_connect_notify (&new_tc0->connection, sst,
1978 tcp_connection_cleanup (new_tc0);
1979 tcp_send_reset (b0, is_ip4);
1983 /* Make sure after data segment processing ACK is sent */
1984 new_tc0->flags |= TCP_CONN_SNDACK;
1986 /* Update rtt with the syn-ack sample */
1987 new_tc0->bytes_acked = 1;
1988 tcp_update_rtt (new_tc0, vnet_buffer (b0)->tcp.ack_number);
1990 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
1993 new_tc0->state = TCP_STATE_SYN_RCVD;
1995 /* Notify app that we have connection */
1996 if (stream_session_connect_notify
1997 (&new_tc0->connection, sst, 0))
1999 tcp_connection_cleanup (new_tc0);
2000 tcp_send_reset (b0, is_ip4);
2006 tcp_make_synack (new_tc0, b0);
2007 next0 = tcp_next_output (is_ip4);
2012 /* Read data, if any */
2013 if (vnet_buffer (b0)->tcp.data_len)
2015 vlib_buffer_advance (b0, vnet_buffer (b0)->tcp.data_offset);
2016 error0 = tcp_segment_rcv (tm, new_tc0, b0,
2017 vnet_buffer (b0)->tcp.data_len,
2019 if (error0 == TCP_ERROR_PURE_ACK)
2020 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2024 tcp_make_ack (new_tc0, b0);
2025 next0 = tcp_next_output (new_tc0->c_is_ip4);
2030 b0->error = error0 ? node->errors[error0] : 0;
2031 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2033 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2034 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2035 clib_memcpy (&t0->tcp_connection, tc0,
2036 sizeof (t0->tcp_connection));
2039 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2040 n_left_to_next, bi0, next0);
2043 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2046 errors = session_manager_flush_enqueue_events (my_thread_index);
2050 vlib_node_increment_counter (vm, tcp4_established_node.index,
2051 TCP_ERROR_EVENT_FIFO_FULL, errors);
2053 vlib_node_increment_counter (vm, tcp6_established_node.index,
2054 TCP_ERROR_EVENT_FIFO_FULL, errors);
2057 return from_frame->n_vectors;
2061 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2062 vlib_frame_t * from_frame)
2064 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2068 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2069 vlib_frame_t * from_frame)
2071 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2075 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2077 .function = tcp4_syn_sent,
2078 .name = "tcp4-syn-sent",
2079 /* Takes a vector of packets. */
2080 .vector_size = sizeof (u32),
2081 .n_errors = TCP_N_ERROR,
2082 .error_strings = tcp_error_strings,
2083 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2086 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2087 foreach_tcp_state_next
2090 .format_trace = format_tcp_rx_trace_short,
2094 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2097 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2099 .function = tcp6_syn_sent_rcv,
2100 .name = "tcp6-syn-sent",
2101 /* Takes a vector of packets. */
2102 .vector_size = sizeof (u32),
2103 .n_errors = TCP_N_ERROR,
2104 .error_strings = tcp_error_strings,
2105 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2108 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2109 foreach_tcp_state_next
2112 .format_trace = format_tcp_rx_trace_short,
2116 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2118 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2119 * as per RFC793 p. 64
2122 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2123 vlib_frame_t * from_frame, int is_ip4)
2125 tcp_main_t *tm = vnet_get_tcp_main ();
2126 u32 n_left_from, next_index, *from, *to_next;
2127 u32 my_thread_index = vm->thread_index, errors = 0;
2129 from = vlib_frame_vector_args (from_frame);
2130 n_left_from = from_frame->n_vectors;
2132 next_index = node->cached_next_index;
2134 while (n_left_from > 0)
2138 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2140 while (n_left_from > 0 && n_left_to_next > 0)
2144 tcp_header_t *tcp0 = 0;
2145 tcp_connection_t *tc0;
2146 u32 next0 = TCP_RCV_PROCESS_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
2153 n_left_to_next -= 1;
2155 b0 = vlib_get_buffer (vm, bi0);
2156 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2158 if (PREDICT_FALSE (tc0 == 0))
2160 error0 = TCP_ERROR_INVALID_CONNECTION;
2164 tcp0 = tcp_buffer_hdr (b0);
2166 /* SYNs, FINs and data consume sequence numbers */
2167 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2168 + tcp_is_syn (tcp0) + tcp_is_fin (tcp0)
2169 + vnet_buffer (b0)->tcp.data_len;
2172 * Special treatment for CLOSED
2176 case TCP_STATE_CLOSED:
2182 * For all other states (except LISTEN)
2185 /* 1-4: check SEQ, RST, SYN */
2187 (tcp_segment_validate (vm, tc0, b0, tcp0, &next0)))
2189 error0 = TCP_ERROR_SEGMENT_INVALID;
2193 /* 5: check the ACK field */
2196 case TCP_STATE_SYN_RCVD:
2198 * If the segment acknowledgment is not acceptable, form a
2200 * <SEQ=SEG.ACK><CTL=RST>
2203 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2205 tcp_send_reset (b0, is_ip4);
2209 /* Update rtt and rto */
2210 tc0->bytes_acked = 1;
2211 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
2213 /* Switch state to ESTABLISHED */
2214 tc0->state = TCP_STATE_ESTABLISHED;
2216 /* Initialize session variables */
2217 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2218 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2219 << tc0->rcv_opts.wscale;
2220 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2221 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2222 stream_session_accept_notify (&tc0->connection);
2224 /* Reset SYN-ACK retransmit timer */
2225 tcp_retransmit_timer_reset (tc0);
2227 case TCP_STATE_ESTABLISHED:
2228 /* We can get packets in established state here because they
2229 * were enqueued before state change */
2230 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2234 case TCP_STATE_FIN_WAIT_1:
2235 /* In addition to the processing for the ESTABLISHED state, if
2236 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2237 * continue processing in that state. */
2238 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2241 /* If FIN is ACKed */
2242 if (tc0->snd_una == tc0->snd_una_max)
2244 ASSERT (tcp_fin (tcp0));
2245 tc0->state = TCP_STATE_FIN_WAIT_2;
2246 /* Stop all timers, 2MSL will be set lower */
2247 tcp_connection_timers_reset (tc0);
2250 case TCP_STATE_FIN_WAIT_2:
2251 /* In addition to the processing for the ESTABLISHED state, if
2252 * the retransmission queue is empty, the user's CLOSE can be
2253 * acknowledged ("ok") but do not delete the TCB. */
2254 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2256 /* check if rtx queue is empty and ack CLOSE TODO */
2258 case TCP_STATE_CLOSE_WAIT:
2259 /* Do the same processing as for the ESTABLISHED state. */
2260 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2263 case TCP_STATE_CLOSING:
2264 /* In addition to the processing for the ESTABLISHED state, if
2265 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2266 * otherwise ignore the segment. */
2267 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2270 /* XXX test that send queue empty */
2271 tc0->state = TCP_STATE_TIME_WAIT;
2275 case TCP_STATE_LAST_ACK:
2276 /* The only thing that [should] arrive in this state is an
2277 * acknowledgment of our FIN. If our FIN is now acknowledged,
2278 * delete the TCB, enter the CLOSED state, and return. */
2280 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2283 /* Apparently our FIN was lost */
2286 /* Don't "make" fin since that increments snd_nxt */
2291 tc0->state = TCP_STATE_CLOSED;
2293 /* Don't delete the connection/session yet. Instead, wait a
2294 * reasonable amount of time until the pipes are cleared. In
2295 * particular, this makes sure that we won't have dead sessions
2296 * when processing events on the tx path */
2297 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2299 /* Stop retransmit */
2300 tcp_retransmit_timer_reset (tc0);
2305 case TCP_STATE_TIME_WAIT:
2306 /* The only thing that can arrive in this state is a
2307 * retransmission of the remote FIN. Acknowledge it, and restart
2308 * the 2 MSL timeout. */
2310 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2313 tcp_make_ack (tc0, b0);
2314 tcp_timer_reset (tc0, TCP_TIMER_WAITCLOSE);
2315 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2324 /* 6: check the URG bit TODO */
2326 /* 7: process the segment text */
2329 case TCP_STATE_ESTABLISHED:
2330 case TCP_STATE_FIN_WAIT_1:
2331 case TCP_STATE_FIN_WAIT_2:
2332 vlib_buffer_advance (b0, vnet_buffer (b0)->tcp.data_offset);
2333 error0 = tcp_segment_rcv (tm, tc0, b0,
2334 vnet_buffer (b0)->tcp.data_len,
2337 case TCP_STATE_CLOSE_WAIT:
2338 case TCP_STATE_CLOSING:
2339 case TCP_STATE_LAST_ACK:
2340 case TCP_STATE_TIME_WAIT:
2341 /* This should not occur, since a FIN has been received from the
2342 * remote side. Ignore the segment text. */
2346 /* 8: check the FIN bit */
2347 if (!tcp_fin (tcp0))
2352 case TCP_STATE_ESTABLISHED:
2353 case TCP_STATE_SYN_RCVD:
2354 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2355 tcp_connection_timers_reset (tc0);
2356 tcp_make_fin (tc0, b0);
2357 next0 = tcp_next_output (tc0->c_is_ip4);
2358 stream_session_disconnect_notify (&tc0->connection);
2359 tc0->state = TCP_STATE_CLOSE_WAIT;
2361 case TCP_STATE_CLOSE_WAIT:
2362 case TCP_STATE_CLOSING:
2363 case TCP_STATE_LAST_ACK:
2366 case TCP_STATE_FIN_WAIT_1:
2367 tc0->state = TCP_STATE_TIME_WAIT;
2368 tcp_connection_timers_reset (tc0);
2369 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2371 case TCP_STATE_FIN_WAIT_2:
2372 /* Got FIN, send ACK! */
2373 tc0->state = TCP_STATE_TIME_WAIT;
2374 tcp_connection_timers_reset (tc0);
2375 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
2376 tcp_make_ack (tc0, b0);
2377 next0 = tcp_next_output (is_ip4);
2379 case TCP_STATE_TIME_WAIT:
2380 /* Remain in the TIME-WAIT state. Restart the 2 MSL time-wait
2383 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2386 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2389 b0->error = error0 ? node->errors[error0] : 0;
2391 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2393 tcp_rx_trace_t *t0 =
2394 vlib_add_trace (vm, node, b0, sizeof (*t0));
2395 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2398 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2399 n_left_to_next, bi0, next0);
2402 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2405 errors = session_manager_flush_enqueue_events (my_thread_index);
2409 vlib_node_increment_counter (vm, tcp4_established_node.index,
2410 TCP_ERROR_EVENT_FIFO_FULL, errors);
2412 vlib_node_increment_counter (vm, tcp6_established_node.index,
2413 TCP_ERROR_EVENT_FIFO_FULL, errors);
2416 return from_frame->n_vectors;
2420 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2421 vlib_frame_t * from_frame)
2423 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2427 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2428 vlib_frame_t * from_frame)
2430 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2434 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2436 .function = tcp4_rcv_process,
2437 .name = "tcp4-rcv-process",
2438 /* Takes a vector of packets. */
2439 .vector_size = sizeof (u32),
2440 .n_errors = TCP_N_ERROR,
2441 .error_strings = tcp_error_strings,
2442 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2445 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2446 foreach_tcp_state_next
2449 .format_trace = format_tcp_rx_trace_short,
2453 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2456 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2458 .function = tcp6_rcv_process,
2459 .name = "tcp6-rcv-process",
2460 /* Takes a vector of packets. */
2461 .vector_size = sizeof (u32),
2462 .n_errors = TCP_N_ERROR,
2463 .error_strings = tcp_error_strings,
2464 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2467 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2468 foreach_tcp_state_next
2471 .format_trace = format_tcp_rx_trace_short,
2475 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2477 vlib_node_registration_t tcp4_listen_node;
2478 vlib_node_registration_t tcp6_listen_node;
2481 * LISTEN state processing as per RFC 793 p. 65
2484 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2485 vlib_frame_t * from_frame, int is_ip4)
2487 u32 n_left_from, next_index, *from, *to_next;
2488 u32 my_thread_index = vm->thread_index;
2489 tcp_main_t *tm = vnet_get_tcp_main ();
2490 u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
2492 from = vlib_frame_vector_args (from_frame);
2493 n_left_from = from_frame->n_vectors;
2495 next_index = node->cached_next_index;
2497 while (n_left_from > 0)
2501 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2503 while (n_left_from > 0 && n_left_to_next > 0)
2508 tcp_header_t *th0 = 0;
2509 tcp_connection_t *lc0;
2512 tcp_connection_t *child0;
2513 u32 error0 = TCP_ERROR_SYNS_RCVD, next0 = TCP_LISTEN_NEXT_DROP;
2520 n_left_to_next -= 1;
2522 b0 = vlib_get_buffer (vm, bi0);
2523 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2527 ip40 = vlib_buffer_get_current (b0);
2528 th0 = ip4_next_header (ip40);
2532 ip60 = vlib_buffer_get_current (b0);
2533 th0 = ip6_next_header (ip60);
2536 /* Create child session. For syn-flood protection use filter */
2538 /* 1. first check for an RST: handled in dispatch */
2539 /* if (tcp_rst (th0))
2542 /* 2. second check for an ACK: handled in dispatch */
2543 /* if (tcp_ack (th0))
2545 tcp_send_reset (b0, is_ip4);
2549 /* 3. check for a SYN (did that already) */
2551 /* Create child session and send SYN-ACK */
2552 pool_get (tm->connections[my_thread_index], child0);
2553 memset (child0, 0, sizeof (*child0));
2555 child0->c_c_index = child0 - tm->connections[my_thread_index];
2556 child0->c_lcl_port = lc0->c_lcl_port;
2557 child0->c_rmt_port = th0->src_port;
2558 child0->c_is_ip4 = is_ip4;
2559 child0->c_thread_index = my_thread_index;
2560 child0->state = TCP_STATE_SYN_RCVD;
2564 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
2565 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
2569 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
2570 sizeof (ip6_address_t));
2571 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
2572 sizeof (ip6_address_t));
2575 if (stream_session_accept (&child0->connection, lc0->c_s_index, sst,
2578 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2582 if (tcp_options_parse (th0, &child0->rcv_opts))
2587 child0->irs = vnet_buffer (b0)->tcp.seq_number;
2588 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
2589 child0->rcv_las = child0->rcv_nxt;
2591 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
2592 * segments are used to initialize PAWS. */
2593 if (tcp_opts_tstamp (&child0->rcv_opts))
2595 child0->tsval_recent = child0->rcv_opts.tsval;
2596 child0->tsval_recent_age = tcp_time_now ();
2599 if (tcp_opts_wscale (&child0->rcv_opts))
2600 child0->snd_wscale = child0->rcv_opts.wscale;
2602 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
2603 << child0->snd_wscale;
2604 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2605 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2607 tcp_connection_init_vars (child0);
2609 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0);
2611 /* Reuse buffer to make syn-ack and send */
2612 tcp_make_synack (child0, b0);
2613 next0 = tcp_next_output (is_ip4);
2616 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2618 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2619 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2620 clib_memcpy (&t0->tcp_connection, lc0,
2621 sizeof (t0->tcp_connection));
2624 b0->error = node->errors[error0];
2626 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2627 n_left_to_next, bi0, next0);
2630 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2632 return from_frame->n_vectors;
2636 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2637 vlib_frame_t * from_frame)
2639 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2643 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2644 vlib_frame_t * from_frame)
2646 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2650 VLIB_REGISTER_NODE (tcp4_listen_node) =
2652 .function = tcp4_listen,
2653 .name = "tcp4-listen",
2654 /* Takes a vector of packets. */
2655 .vector_size = sizeof (u32),
2656 .n_errors = TCP_N_ERROR,
2657 .error_strings = tcp_error_strings,
2658 .n_next_nodes = TCP_LISTEN_N_NEXT,
2661 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2662 foreach_tcp_state_next
2665 .format_trace = format_tcp_rx_trace_short,
2669 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
2672 VLIB_REGISTER_NODE (tcp6_listen_node) =
2674 .function = tcp6_listen,
2675 .name = "tcp6-listen",
2676 /* Takes a vector of packets. */
2677 .vector_size = sizeof (u32),
2678 .n_errors = TCP_N_ERROR,
2679 .error_strings = tcp_error_strings,
2680 .n_next_nodes = TCP_LISTEN_N_NEXT,
2683 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2684 foreach_tcp_state_next
2687 .format_trace = format_tcp_rx_trace_short,
2691 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
2693 vlib_node_registration_t tcp4_input_node;
2694 vlib_node_registration_t tcp6_input_node;
2696 typedef enum _tcp_input_next
2698 TCP_INPUT_NEXT_DROP,
2699 TCP_INPUT_NEXT_LISTEN,
2700 TCP_INPUT_NEXT_RCV_PROCESS,
2701 TCP_INPUT_NEXT_SYN_SENT,
2702 TCP_INPUT_NEXT_ESTABLISHED,
2703 TCP_INPUT_NEXT_RESET,
2707 #define foreach_tcp4_input_next \
2708 _ (DROP, "error-drop") \
2709 _ (LISTEN, "tcp4-listen") \
2710 _ (RCV_PROCESS, "tcp4-rcv-process") \
2711 _ (SYN_SENT, "tcp4-syn-sent") \
2712 _ (ESTABLISHED, "tcp4-established") \
2713 _ (RESET, "tcp4-reset")
2715 #define foreach_tcp6_input_next \
2716 _ (DROP, "error-drop") \
2717 _ (LISTEN, "tcp6-listen") \
2718 _ (RCV_PROCESS, "tcp6-rcv-process") \
2719 _ (SYN_SENT, "tcp6-syn-sent") \
2720 _ (ESTABLISHED, "tcp6-established") \
2721 _ (RESET, "tcp6-reset")
2723 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
2726 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2727 vlib_frame_t * from_frame, int is_ip4)
2729 u32 n_left_from, next_index, *from, *to_next;
2730 u32 my_thread_index = vm->thread_index;
2731 tcp_main_t *tm = vnet_get_tcp_main ();
2733 from = vlib_frame_vector_args (from_frame);
2734 n_left_from = from_frame->n_vectors;
2736 next_index = node->cached_next_index;
2738 while (n_left_from > 0)
2742 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2744 while (n_left_from > 0 && n_left_to_next > 0)
2746 int n_advance_bytes0, n_data_bytes0;
2749 tcp_header_t *tcp0 = 0;
2750 tcp_connection_t *tc0;
2753 u32 error0 = TCP_ERROR_NO_LISTENER, next0 = TCP_INPUT_NEXT_DROP;
2761 n_left_to_next -= 1;
2763 b0 = vlib_get_buffer (vm, bi0);
2764 vnet_buffer (b0)->tcp.flags = 0;
2766 /* Checksum computed by ipx_local no need to compute again */
2770 ip40 = vlib_buffer_get_current (b0);
2771 tcp0 = ip4_next_header (ip40);
2772 n_advance_bytes0 = (ip4_header_bytes (ip40)
2773 + tcp_header_bytes (tcp0));
2774 n_data_bytes0 = clib_net_to_host_u16 (ip40->length)
2777 /* lookup session */
2779 (tcp_connection_t *)
2780 stream_session_lookup_transport_wt4 (&ip40->dst_address,
2784 SESSION_TYPE_IP4_TCP,
2789 ip60 = vlib_buffer_get_current (b0);
2790 tcp0 = ip6_next_header (ip60);
2791 n_advance_bytes0 = tcp_header_bytes (tcp0);
2792 n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length)
2794 n_advance_bytes0 += sizeof (ip60[0]);
2797 (tcp_connection_t *)
2798 stream_session_lookup_transport_wt6 (&ip60->src_address,
2802 SESSION_TYPE_IP6_TCP,
2807 if (PREDICT_FALSE (n_advance_bytes0 < 0))
2809 error0 = TCP_ERROR_LENGTH;
2813 /* Session exists */
2814 if (PREDICT_TRUE (0 != tc0))
2816 /* Save connection index */
2817 vnet_buffer (b0)->tcp.connection_index = tc0->c_c_index;
2818 vnet_buffer (b0)->tcp.seq_number =
2819 clib_net_to_host_u32 (tcp0->seq_number);
2820 vnet_buffer (b0)->tcp.ack_number =
2821 clib_net_to_host_u32 (tcp0->ack_number);
2823 vnet_buffer (b0)->tcp.hdr_offset = (u8 *) tcp0
2824 - (u8 *) vlib_buffer_get_current (b0);
2825 vnet_buffer (b0)->tcp.data_offset = n_advance_bytes0;
2826 vnet_buffer (b0)->tcp.data_len = n_data_bytes0;
2828 flags0 = tcp0->flags & filter_flags;
2829 next0 = tm->dispatch_table[tc0->state][flags0].next;
2830 error0 = tm->dispatch_table[tc0->state][flags0].error;
2832 if (PREDICT_FALSE (error0 == TCP_ERROR_DISPATCH
2833 || next0 == TCP_INPUT_NEXT_RESET))
2835 /* Overload tcp flags to store state */
2836 tcp_state_t state0 = tc0->state;
2837 vnet_buffer (b0)->tcp.flags = tc0->state;
2839 if (error0 == TCP_ERROR_DISPATCH)
2840 clib_warning ("disp error state %U flags %U",
2841 format_tcp_state, state0, format_tcp_flags,
2848 next0 = TCP_INPUT_NEXT_RESET;
2849 error0 = TCP_ERROR_NO_LISTENER;
2853 b0->error = error0 ? node->errors[error0] : 0;
2855 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2857 tcp_rx_trace_t *t0 =
2858 vlib_add_trace (vm, node, b0, sizeof (*t0));
2859 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2861 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2862 n_left_to_next, bi0, next0);
2865 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2868 return from_frame->n_vectors;
2872 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2873 vlib_frame_t * from_frame)
2875 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2879 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2880 vlib_frame_t * from_frame)
2882 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2886 VLIB_REGISTER_NODE (tcp4_input_node) =
2888 .function = tcp4_input,
2889 .name = "tcp4-input",
2890 /* Takes a vector of packets. */
2891 .vector_size = sizeof (u32),
2892 .n_errors = TCP_N_ERROR,
2893 .error_strings = tcp_error_strings,
2894 .n_next_nodes = TCP_INPUT_N_NEXT,
2897 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
2898 foreach_tcp4_input_next
2901 .format_buffer = format_tcp_header,
2902 .format_trace = format_tcp_rx_trace,
2906 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
2909 VLIB_REGISTER_NODE (tcp6_input_node) =
2911 .function = tcp6_input,
2912 .name = "tcp6-input",
2913 /* Takes a vector of packets. */
2914 .vector_size = sizeof (u32),
2915 .n_errors = TCP_N_ERROR,
2916 .error_strings = tcp_error_strings,
2917 .n_next_nodes = TCP_INPUT_N_NEXT,
2920 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
2921 foreach_tcp6_input_next
2924 .format_buffer = format_tcp_header,
2925 .format_trace = format_tcp_rx_trace,
2929 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
2932 tcp_dispatch_table_init (tcp_main_t * tm)
2935 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
2936 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
2938 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
2939 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
2942 #define _(t,f,n,e) \
2944 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
2945 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
2948 /* SYNs for new connections -> tcp-listen. */
2949 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
2950 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
2951 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_NONE);
2952 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
2954 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
2955 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2956 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2957 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2958 /* SYN-ACK for a SYN */
2959 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
2961 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
2962 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
2963 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
2965 /* ACK for for established connection -> tcp-established. */
2966 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2967 /* FIN for for established connection -> tcp-established. */
2968 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2969 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
2971 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2972 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
2974 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
2975 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
2977 /* ACK or FIN-ACK to our FIN */
2978 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2979 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
2981 /* FIN in reply to our FIN from the other side */
2982 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2983 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2984 /* FIN confirming that the peer (app) has closed */
2985 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2986 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2987 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
2989 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2990 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
2992 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2993 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2994 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
2996 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2997 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
2998 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3000 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3001 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_CONNECTION_CLOSED);
3002 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3003 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3004 TCP_ERROR_CONNECTION_CLOSED);
3009 tcp_input_init (vlib_main_t * vm)
3011 clib_error_t *error = 0;
3012 tcp_main_t *tm = vnet_get_tcp_main ();
3014 if ((error = vlib_call_init_function (vm, tcp_init)))
3017 /* Initialize dispatch table. */
3018 tcp_dispatch_table_init (tm);
3023 VLIB_INIT_FUNCTION (tcp_input_init);
3026 * fd.io coding-style-patch-verification: ON
3029 * eval: (c-set-style "gnu")