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 /* TODO implement RFC 5961 */
353 tcp_make_ack (tc0, b0);
354 *next0 = tcp_next_output (tc0->c_is_ip4);
355 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0);
359 /* If segment in window, save timestamp */
360 tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
361 vnet_buffer (b0)->tcp.seq_end);
366 tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0)
368 /* SND.UNA =< SEG.ACK =< SND.NXT */
369 return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number)
370 && seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt));
374 * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
376 * Note that although the original article, srtt and rttvar are scaled
377 * to minimize round-off errors, here we don't. Instead, we rely on
378 * better precision time measurements.
380 * TODO support us rtt resolution
383 tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
389 err = mrtt - tc->srtt;
391 /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
392 * The increase should be bound */
393 tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
394 diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
395 tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
399 /* First measurement. */
401 tc->rttvar = mrtt >> 1;
406 tcp_update_rto (tcp_connection_t * tc)
408 tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
409 tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
412 /** Update RTT estimate and RTO timer
414 * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
415 * timing. Middle boxes are known to fiddle with TCP options so we
416 * should give higher priority to ACK timing.
418 * return 1 if valid rtt 0 otherwise
421 tcp_update_rtt (tcp_connection_t * tc, u32 ack)
426 /* Determine if only rtx bytes are acked. */
427 rtx_acked = tcp_in_cong_recovery (tc) || !tc->bytes_acked;
429 /* Karn's rule, part 1. Don't use retransmitted segments to estimate
430 * RTT because they're ambiguous. */
431 if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq) && !rtx_acked)
433 mrtt = tcp_time_now () - tc->rtt_ts;
435 /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
436 * snd_una, i.e., the left side of the send window:
437 * seq_lt (tc->snd_una, ack). */
438 else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr
441 mrtt = tcp_time_now () - tc->rcv_opts.tsecr;
444 /* Allow measuring of a new RTT */
447 /* If ACK moves left side of the wnd make sure boff is 0, even if mrtt is
452 /* Ignore dubious measurements */
453 if (mrtt == 0 || mrtt > TCP_RTT_MAX)
456 tcp_estimate_rtt (tc, mrtt);
463 * Dequeue bytes that have been acked and while at it update RTT estimates.
466 tcp_dequeue_acked (tcp_connection_t * tc, u32 ack)
468 /* Dequeue the newly ACKed add SACKed bytes */
469 stream_session_dequeue_drop (&tc->connection,
470 tc->bytes_acked + tc->sack_sb.snd_una_adv);
472 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
474 /* Update rtt and rto */
475 tcp_update_rtt (tc, ack);
477 /* If everything has been acked, stop retransmit timer
478 * otherwise update. */
479 tcp_retransmit_timer_update (tc);
483 * Check if duplicate ack as per RFC5681 Sec. 2
486 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
489 return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
490 && seq_gt (tc->snd_una_max, tc->snd_una)
491 && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
492 && (prev_snd_wnd == tc->snd_wnd));
496 tcp_is_lost_fin (tcp_connection_t * tc)
498 if ((tc->flags & TCP_CONN_FINSNT) && tc->snd_una_max - tc->snd_una == 1)
504 * Checks if ack is a congestion control event.
507 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
508 u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
510 /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
511 * defined to be 'duplicate' */
512 *is_dack = tc->sack_sb.last_sacked_bytes
513 || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
515 return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
519 scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
521 sack_scoreboard_hole_t *next, *prev;
523 if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
525 next = pool_elt_at_index (sb->holes, hole->next);
526 next->prev = hole->prev;
530 sb->tail = hole->prev;
533 if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
535 prev = pool_elt_at_index (sb->holes, hole->prev);
536 prev->next = hole->next;
540 sb->head = hole->next;
543 if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
544 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
546 /* Poison the entry */
548 memset (hole, 0xfe, sizeof (*hole));
550 pool_put (sb->holes, hole);
553 sack_scoreboard_hole_t *
554 scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
557 sack_scoreboard_hole_t *hole, *next, *prev;
560 pool_get (sb->holes, hole);
561 memset (hole, 0, sizeof (*hole));
565 hole_index = scoreboard_hole_index (sb, hole);
567 prev = scoreboard_get_hole (sb, prev_index);
570 hole->prev = prev_index;
571 hole->next = prev->next;
573 if ((next = scoreboard_next_hole (sb, hole)))
574 next->prev = hole_index;
576 sb->tail = hole_index;
578 prev->next = hole_index;
582 sb->head = hole_index;
583 hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
584 hole->next = TCP_INVALID_SACK_HOLE_INDEX;
591 scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
593 sack_scoreboard_hole_t *hole, *prev;
594 u32 bytes = 0, blks = 0;
597 sb->sacked_bytes = 0;
598 hole = scoreboard_last_hole (sb);
602 if (seq_gt (sb->high_sacked, hole->end))
604 bytes = sb->high_sacked - hole->end;
608 while ((prev = scoreboard_prev_hole (sb, hole))
609 && (bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
610 && blks < TCP_DUPACK_THRESHOLD))
612 bytes += hole->start - prev->end;
619 sb->lost_bytes += scoreboard_hole_bytes (hole);
622 hole = scoreboard_prev_hole (sb, hole);
624 bytes += prev->start - hole->end;
626 sb->sacked_bytes = bytes;
630 * Figure out the next hole to retransmit
632 * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
634 sack_scoreboard_hole_t *
635 scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
636 sack_scoreboard_hole_t * start,
638 u8 * can_rescue, u8 * snd_limited)
640 sack_scoreboard_hole_t *hole = 0;
642 hole = start ? start : scoreboard_first_hole (sb);
643 while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
644 hole = scoreboard_next_hole (sb, hole);
646 /* Nothing, return */
649 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
653 /* Rule (1): if higher than rxt, less than high_sacked and lost */
654 if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
656 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
660 /* Rule (2): output takes care of transmitting new data */
661 if (!have_sent_1_smss)
664 sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
666 /* Rule (3): if hole not lost */
667 else if (seq_lt (hole->start, sb->high_sacked))
670 sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
672 /* Rule (4): if hole beyond high_sacked */
675 ASSERT (seq_geq (hole->start, sb->high_sacked));
678 /* HighRxt MUST NOT be updated */
683 if (hole && seq_lt (sb->high_rxt, hole->start))
684 sb->high_rxt = hole->start;
690 scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 seq)
692 sack_scoreboard_hole_t *hole;
693 hole = scoreboard_first_hole (sb);
696 seq = seq_gt (seq, hole->start) ? seq : hole->start;
697 sb->cur_rxt_hole = sb->head;
703 * Test that scoreboard is sane after recovery
705 * Returns 1 if scoreboard is empty or if first hole beyond
709 tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
711 sack_scoreboard_hole_t *hole;
712 hole = scoreboard_first_hole (&tc->sack_sb);
713 return (!hole || seq_geq (hole->start, tc->snd_una));
717 tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
719 sack_scoreboard_t *sb = &tc->sack_sb;
720 sack_block_t *blk, tmp;
721 sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
722 u32 blk_index = 0, old_sacked_bytes, hole_index;
725 sb->last_sacked_bytes = 0;
727 old_sacked_bytes = sb->sacked_bytes;
728 sb->last_bytes_delivered = 0;
730 if (!tcp_opts_sack (&tc->rcv_opts)
731 && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
734 /* Remove invalid blocks */
735 blk = tc->rcv_opts.sacks;
736 while (blk < vec_end (tc->rcv_opts.sacks))
738 if (seq_lt (blk->start, blk->end)
739 && seq_gt (blk->start, tc->snd_una)
740 && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_una_max))
745 vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
748 /* Add block for cumulative ack */
749 if (seq_gt (ack, tc->snd_una))
751 tmp.start = tc->snd_una;
753 vec_add1 (tc->rcv_opts.sacks, tmp);
756 if (vec_len (tc->rcv_opts.sacks) == 0)
759 tcp_scoreboard_trace_add (tc, ack);
761 /* Make sure blocks are ordered */
762 for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
763 for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
764 if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
766 tmp = tc->rcv_opts.sacks[i];
767 tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
768 tc->rcv_opts.sacks[j] = tmp;
771 if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
773 /* If no holes, insert the first that covers all outstanding bytes */
774 last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
775 tc->snd_una, tc->snd_una_max);
776 sb->tail = scoreboard_hole_index (sb, last_hole);
777 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
778 sb->high_sacked = tmp.end;
782 /* If we have holes but snd_una_max is beyond the last hole, update
784 tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
785 last_hole = scoreboard_last_hole (sb);
786 if (seq_gt (tc->snd_una_max, last_hole->end))
788 if (seq_geq (last_hole->start, sb->high_sacked))
790 last_hole->end = tc->snd_una_max;
792 /* New hole after high sacked block */
793 else if (seq_lt (sb->high_sacked, tc->snd_una_max))
795 scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
799 /* Keep track of max byte sacked for when the last hole
801 if (seq_gt (tmp.end, sb->high_sacked))
802 sb->high_sacked = tmp.end;
805 /* Walk the holes with the SACK blocks */
806 hole = pool_elt_at_index (sb->holes, sb->head);
807 while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
809 blk = &tc->rcv_opts.sacks[blk_index];
810 if (seq_leq (blk->start, hole->start))
812 /* Block covers hole. Remove hole */
813 if (seq_geq (blk->end, hole->end))
815 next_hole = scoreboard_next_hole (sb, hole);
817 /* Byte accounting: snd_una needs to be advanced */
822 if (seq_lt (ack, next_hole->start))
823 sb->snd_una_adv = next_hole->start - ack;
824 sb->last_bytes_delivered +=
825 next_hole->start - hole->end;
829 ASSERT (seq_geq (sb->high_sacked, ack));
830 sb->snd_una_adv = sb->high_sacked - ack;
831 sb->last_bytes_delivered += sb->high_sacked - hole->end;
835 scoreboard_remove_hole (sb, hole);
838 /* Partial 'head' overlap */
841 if (seq_gt (blk->end, hole->start))
843 hole->start = blk->end;
850 /* Hole must be split */
851 if (seq_lt (blk->end, hole->end))
853 hole_index = scoreboard_hole_index (sb, hole);
854 next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
857 /* Pool might've moved */
858 hole = scoreboard_get_hole (sb, hole_index);
859 hole->end = blk->start;
861 ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
863 else if (seq_lt (blk->start, hole->end))
865 hole->end = blk->start;
867 hole = scoreboard_next_hole (sb, hole);
871 scoreboard_update_bytes (tc, sb);
872 sb->last_sacked_bytes = sb->sacked_bytes
873 - (old_sacked_bytes - sb->last_bytes_delivered);
874 ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes);
875 ASSERT (sb->sacked_bytes == 0
876 || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
877 ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
878 - seq_max (tc->snd_una, ack));
879 ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
880 || sb->holes[sb->head].start == ack + sb->snd_una_adv);
884 * Try to update snd_wnd based on feedback received from peer.
886 * If successful, and new window is 'effectively' 0, activate persist
890 tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
892 /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
893 * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
894 if (seq_lt (tc->snd_wl1, seq)
895 || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
897 tc->snd_wnd = snd_wnd;
900 TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
902 if (tc->snd_wnd < tc->snd_mss)
904 /* Set persist timer if not set and we just got 0 wnd */
905 if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
906 && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
907 tcp_persist_timer_set (tc);
911 tcp_persist_timer_reset (tc);
912 if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
922 tcp_cc_init_congestion (tcp_connection_t * tc)
924 tcp_fastrecovery_on (tc);
925 tc->snd_congestion = tc->snd_una_max;
926 tc->cc_algo->congestion (tc);
927 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
931 tcp_cc_recovery_exit (tcp_connection_t * tc)
937 tcp_recovery_off (tc);
941 tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
943 tc->cc_algo->recovered (tc);
944 tc->snd_rxt_bytes = 0;
946 tcp_fastrecovery_off (tc);
947 tcp_fastrecovery_1_smss_off (tc);
951 tcp_cc_congestion_undo (tcp_connection_t * tc)
953 tc->cwnd = tc->prev_cwnd;
954 tc->ssthresh = tc->prev_ssthresh;
955 tc->snd_nxt = tc->snd_una_max;
957 if (tcp_in_recovery (tc))
958 tcp_cc_recovery_exit (tc);
959 ASSERT (tc->rto_boff == 0);
960 /* TODO extend for fastrecovery */
964 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
966 return (tcp_in_recovery (tc)
968 && tcp_opts_tstamp (&tc->rcv_opts)
969 && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
973 tcp_cc_recover (tcp_connection_t * tc)
975 ASSERT (tcp_in_cong_recovery (tc));
976 if (tcp_cc_is_spurious_retransmit (tc))
978 tcp_cc_congestion_undo (tc);
982 if (tcp_in_recovery (tc))
983 tcp_cc_recovery_exit (tc);
984 else if (tcp_in_fastrecovery (tc))
985 tcp_cc_fastrecovery_exit (tc);
987 ASSERT (tc->rto_boff == 0);
988 ASSERT (!tcp_in_cong_recovery (tc));
989 ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
990 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
995 tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
997 ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
999 /* Congestion avoidance */
1000 tc->cc_algo->rcv_ack (tc);
1001 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1003 /* If a cumulative ack, make sure dupacks is 0 */
1004 tc->rcv_dupacks = 0;
1006 /* When dupacks hits the threshold we only enter fast retransmit if
1007 * cumulative ack covers more than snd_congestion. Should snd_una
1008 * wrap this test may fail under otherwise valid circumstances.
1009 * Therefore, proactively update snd_congestion when wrap detected. */
1011 (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
1012 && seq_gt (tc->snd_congestion, tc->snd_una)))
1013 tc->snd_congestion = tc->snd_una - 1;
1017 tcp_should_fastrecover_sack (tcp_connection_t * tc)
1019 return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
1023 tcp_should_fastrecover (tcp_connection_t * tc)
1025 return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
1026 || tcp_should_fastrecover_sack (tc));
1030 * One function to rule them all ... and in the darkness bind them
1033 tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
1038 * Duplicate ACK. Check if we should enter fast recovery, or if already in
1039 * it account for the bytes that left the network.
1043 ASSERT (tc->snd_una != tc->snd_una_max
1044 || tc->sack_sb.last_sacked_bytes);
1048 if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
1050 ASSERT (tcp_in_fastrecovery (tc));
1051 /* Pure duplicate ack. If some data got acked, it's handled lower */
1052 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1055 else if (tcp_should_fastrecover (tc))
1057 /* Things are already bad */
1058 if (tcp_in_cong_recovery (tc))
1060 tc->rcv_dupacks = 0;
1061 goto partial_ack_test;
1064 /* If of of the two conditions lower hold, reset dupacks because
1065 * we're probably after timeout (RFC6582 heuristics).
1066 * If Cumulative ack does not cover more than congestion threshold,
1068 * 1) The following doesn't hold: The congestion window is greater
1069 * than SMSS bytes and the difference between highest_ack
1070 * and prev_highest_ack is at most 4*SMSS bytes
1071 * 2) Echoed timestamp in the last non-dup ack does not equal the
1074 if (seq_leq (tc->snd_una, tc->snd_congestion)
1075 && ((!(tc->cwnd > tc->snd_mss
1076 && tc->bytes_acked <= 4 * tc->snd_mss))
1077 || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
1079 tc->rcv_dupacks = 0;
1083 tcp_cc_init_congestion (tc);
1084 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1086 /* The first segment MUST be retransmitted */
1087 tcp_retransmit_first_unacked (tc);
1089 /* Post retransmit update cwnd to ssthresh and account for the
1090 * three segments that have left the network and should've been
1091 * buffered at the receiver XXX */
1092 tc->cwnd = tc->ssthresh + tc->rcv_dupacks * tc->snd_mss;
1093 ASSERT (tc->cwnd >= tc->snd_mss);
1095 /* If cwnd allows, send more data */
1096 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1098 scoreboard_init_high_rxt (&tc->sack_sb,
1099 tc->snd_una + tc->snd_mss);
1100 tcp_fast_retransmit_sack (tc);
1104 tcp_fast_retransmit_no_sack (tc);
1109 else if (!tc->bytes_acked
1110 || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
1112 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
1121 if (!tc->bytes_acked)
1126 * Legitimate ACK. 1) See if we can exit recovery
1128 /* XXX limit this only to first partial ack? */
1129 tcp_retransmit_timer_update (tc);
1131 if (seq_geq (tc->snd_una, tc->snd_congestion))
1133 /* If spurious return, we've already updated everything */
1134 if (tcp_cc_recover (tc))
1136 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1140 tc->snd_nxt = tc->snd_una_max;
1142 /* Treat as congestion avoidance ack */
1143 tc->cc_algo->rcv_ack (tc);
1144 tc->tsecr_last_ack = tc->rcv_opts.tsecr;
1149 * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
1151 TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
1153 /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
1154 * reset dupacks to 0 */
1155 tc->rcv_dupacks = 0;
1157 tcp_retransmit_first_unacked (tc);
1159 /* Post RTO timeout don't try anything fancy */
1160 if (tcp_in_recovery (tc))
1163 /* Remove retransmitted bytes that have been delivered */
1164 ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
1165 >= tc->sack_sb.last_bytes_delivered);
1167 if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
1169 /* If we have sacks and we haven't gotten an ack beyond high_rxt,
1170 * remove sacked bytes delivered */
1171 rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
1172 - tc->sack_sb.last_bytes_delivered;
1173 ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
1174 tc->snd_rxt_bytes -= rxt_delivered;
1178 /* Either all retransmitted holes have been acked, or we're
1179 * "in the blind" and retransmitting segment by segment */
1180 tc->snd_rxt_bytes = 0;
1183 tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
1186 * Since this was a partial ack, try to retransmit some more data
1188 tcp_fast_retransmit (tc);
1192 tcp_cc_init (tcp_connection_t * tc)
1194 tc->cc_algo = tcp_cc_algo_get (TCP_CC_NEWRENO);
1195 tc->cc_algo->init (tc);
1199 * Process incoming ACK
1202 tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
1203 tcp_header_t * th, u32 * next, u32 * error)
1205 u32 prev_snd_wnd, prev_snd_una;
1208 TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
1210 /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
1211 if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
1213 /* If we have outstanding data and this is within the window, accept it,
1214 * probably retransmit has timed out. Otherwise ACK segment and then
1216 if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
1218 tcp_make_ack (tc, b);
1219 *next = tcp_next_output (tc->c_is_ip4);
1220 *error = TCP_ERROR_ACK_INVALID;
1221 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
1222 vnet_buffer (b)->tcp.ack_number);
1226 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
1227 vnet_buffer (b)->tcp.ack_number);
1229 tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
1230 *error = TCP_ERROR_ACK_FUTURE;
1233 /* If old ACK, probably it's an old dupack */
1234 if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
1236 *error = TCP_ERROR_ACK_OLD;
1237 TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
1238 vnet_buffer (b)->tcp.ack_number);
1239 if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
1241 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc);
1242 tcp_cc_handle_event (tc, 1);
1244 /* Don't drop yet */
1249 * Looks okay, process feedback
1252 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1253 tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
1255 prev_snd_wnd = tc->snd_wnd;
1256 prev_snd_una = tc->snd_una;
1257 tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
1258 vnet_buffer (b)->tcp.ack_number,
1259 clib_net_to_host_u16 (th->window) << tc->snd_wscale);
1260 tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
1261 tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
1262 tcp_validate_txf_size (tc, tc->bytes_acked);
1264 if (tc->bytes_acked)
1265 tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
1267 TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
1270 * Check if we have congestion event
1273 if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
1275 tcp_cc_handle_event (tc, is_dack);
1276 *error = TCP_ERROR_ACK_DUP;
1277 TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
1278 return vnet_buffer (b)->tcp.data_len ? 0 : -1;
1282 * Update congestion control (slow start/congestion avoidance)
1284 tcp_cc_update (tc, b);
1290 tcp_sack_vector_is_sane (sack_block_t * sacks)
1293 for (i = 1; i < vec_len (sacks); i++)
1295 if (sacks[i - 1].end == sacks[i].start)
1302 * Build SACK list as per RFC2018.
1304 * Makes sure the first block contains the segment that generated the current
1305 * ACK and the following ones are the ones most recently reported in SACK
1308 * @param tc TCP connection for which the SACK list is updated
1309 * @param start Start sequence number of the newest SACK block
1310 * @param end End sequence of the newest SACK block
1313 tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
1315 sack_block_t *new_list = 0, *block = 0;
1318 /* If the first segment is ooo add it to the list. Last write might've moved
1319 * rcv_nxt over the first segment. */
1320 if (seq_lt (tc->rcv_nxt, start))
1322 vec_add2 (new_list, block, 1);
1323 block->start = start;
1327 /* Find the blocks still worth keeping. */
1328 for (i = 0; i < vec_len (tc->snd_sacks); i++)
1330 /* Discard if rcv_nxt advanced beyond current block */
1331 if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
1334 /* Merge or drop if segment overlapped by the new segment */
1335 if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
1336 && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
1338 if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
1339 new_list[0].start = tc->snd_sacks[i].start;
1340 if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
1341 new_list[0].end = tc->snd_sacks[i].end;
1345 /* Save to new SACK list if we have space. */
1346 if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
1348 vec_add1 (new_list, tc->snd_sacks[i]);
1352 clib_warning ("sack discarded");
1356 ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
1358 /* Replace old vector with new one */
1359 vec_free (tc->snd_sacks);
1360 tc->snd_sacks = new_list;
1362 /* Segments should not 'touch' */
1363 ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
1366 /** Enqueue data for delivery to application */
1368 tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
1373 ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1375 /* Pure ACK. Update rcv_nxt and be done. */
1376 if (PREDICT_FALSE (data_len == 0))
1378 return TCP_ERROR_PURE_ACK;
1381 written = stream_session_enqueue_data (&tc->connection, b, 0,
1382 1 /* queue event */ , 1);
1384 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
1386 /* Update rcv_nxt */
1387 if (PREDICT_TRUE (written == data_len))
1389 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end;
1391 /* If more data written than expected, account for out-of-order bytes. */
1392 else if (written > data_len)
1394 tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end + written - data_len;
1396 /* Send ACK confirming the update */
1397 tc->flags |= TCP_CONN_SNDACK;
1399 else if (written > 0)
1401 /* We've written something but FIFO is probably full now */
1402 tc->rcv_nxt += written;
1404 /* Depending on how fast the app is, all remaining buffers in burst will
1405 * not be enqueued. Inform peer */
1406 tc->flags |= TCP_CONN_SNDACK;
1408 return TCP_ERROR_PARTIALLY_ENQUEUED;
1412 tc->flags |= TCP_CONN_SNDACK;
1413 return TCP_ERROR_FIFO_FULL;
1416 /* Update SACK list if need be */
1417 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1419 /* Remove SACK blocks that have been delivered */
1420 tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
1423 return TCP_ERROR_ENQUEUED;
1426 /** Enqueue out-of-order data */
1428 tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
1431 stream_session_t *s0;
1434 ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
1436 /* Pure ACK. Do nothing */
1437 if (PREDICT_FALSE (data_len == 0))
1439 return TCP_ERROR_PURE_ACK;
1442 /* Enqueue out-of-order data with relative offset */
1443 rv = stream_session_enqueue_data (&tc->connection, b,
1444 vnet_buffer (b)->tcp.seq_number -
1445 tc->rcv_nxt, 0 /* queue event */ , 0);
1447 /* Nothing written */
1450 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
1451 return TCP_ERROR_FIFO_FULL;
1454 TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
1456 /* Update SACK list if in use */
1457 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1459 ooo_segment_t *newest;
1462 s0 = stream_session_get (tc->c_s_index, tc->c_thread_index);
1464 /* Get the newest segment from the fifo */
1465 newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
1468 offset = ooo_segment_offset (s0->server_rx_fifo, newest);
1469 ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
1470 start = tc->rcv_nxt + offset;
1471 end = start + ooo_segment_length (s0->server_rx_fifo, newest);
1472 tcp_update_sack_list (tc, start, end);
1473 svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
1477 return TCP_ERROR_ENQUEUED;
1481 * Check if ACK could be delayed. If ack can be delayed, it should return
1482 * true for a full frame. If we're always acking return 0.
1485 tcp_can_delack (tcp_connection_t * tc)
1487 /* Send ack if ... */
1489 /* just sent a rcv wnd 0 */
1490 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
1491 /* constrained to send ack */
1492 || (tc->flags & TCP_CONN_SNDACK) != 0
1493 /* we're almost out of tx wnd */
1494 || tcp_available_snd_space (tc) < 4 * tc->snd_mss)
1501 tcp_segment_rcv (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b,
1504 u32 error = 0, n_bytes_to_drop, n_data_bytes;
1506 vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
1507 n_data_bytes = vnet_buffer (b)->tcp.data_len;
1508 ASSERT (n_data_bytes);
1510 /* Handle out-of-order data */
1511 if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
1513 /* Old sequence numbers allowed through because they overlapped
1515 if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
1517 error = TCP_ERROR_SEGMENT_OLD;
1518 *next0 = TCP_NEXT_DROP;
1520 /* Completely in the past (possible retransmit) */
1521 if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
1523 /* Ack retransmissions since we may not have any data to send */
1524 tcp_make_ack (tc, b);
1525 *next0 = tcp_next_output (tc->c_is_ip4);
1529 /* Chop off the bytes in the past */
1530 n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
1531 n_data_bytes -= n_bytes_to_drop;
1532 vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
1533 vlib_buffer_advance (b, n_bytes_to_drop);
1538 error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
1540 /* N.B. Should not filter burst of dupacks. Two issues 1) dupacks open
1541 * cwnd on remote peer when congested 2) acks leaving should have the
1542 * latest rcv_wnd since the burst may eaten up all of it, so only the
1543 * old ones could be filtered.
1546 /* RFC2581: Send DUPACK for fast retransmit */
1547 tcp_make_ack (tc, b);
1548 *next0 = tcp_next_output (tc->c_is_ip4);
1550 /* Mark as DUPACK. We may filter these in output if
1551 * the burst fills the holes. */
1553 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
1555 TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc);
1561 /* In order data, enqueue. Fifo figures out by itself if any out-of-order
1562 * segments can be enqueued after fifo tail offset changes. */
1563 error = tcp_session_enqueue_data (tc, b, n_data_bytes);
1565 /* Check if ACK can be delayed */
1566 if (tcp_can_delack (tc))
1568 if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
1569 tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
1573 *next0 = tcp_next_output (tc->c_is_ip4);
1574 tcp_make_ack (tc, b);
1582 tcp_header_t tcp_header;
1583 tcp_connection_t tcp_connection;
1587 format_tcp_rx_trace (u8 * s, va_list * args)
1589 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1590 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1591 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1592 uword indent = format_get_indent (s);
1594 s = format (s, "%U\n%U%U",
1595 format_tcp_header, &t->tcp_header, 128,
1596 format_white_space, indent,
1597 format_tcp_connection, &t->tcp_connection, 1);
1603 format_tcp_rx_trace_short (u8 * s, va_list * args)
1605 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1606 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1607 tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
1609 s = format (s, "%d -> %d (%U)",
1610 clib_net_to_host_u16 (t->tcp_header.src_port),
1611 clib_net_to_host_u16 (t->tcp_header.dst_port), format_tcp_state,
1612 t->tcp_connection.state);
1618 tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
1619 tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
1623 clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
1627 th0 = tcp_buffer_hdr (b0);
1629 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1633 tcp_established_inc_counter (vlib_main_t * vm, u8 is_ip4, u8 evt, u8 val)
1635 if (PREDICT_TRUE (!val))
1639 vlib_node_increment_counter (vm, tcp4_established_node.index, evt, val);
1641 vlib_node_increment_counter (vm, tcp6_established_node.index, evt, val);
1645 tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1646 vlib_frame_t * from_frame, int is_ip4)
1648 u32 n_left_from, next_index, *from, *to_next;
1649 u32 my_thread_index = vm->thread_index, errors = 0;
1650 tcp_main_t *tm = vnet_get_tcp_main ();
1653 from = vlib_frame_vector_args (from_frame);
1654 n_left_from = from_frame->n_vectors;
1656 next_index = node->cached_next_index;
1658 while (n_left_from > 0)
1662 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1663 while (n_left_from > 0 && n_left_to_next > 0)
1667 tcp_header_t *th0 = 0;
1668 tcp_connection_t *tc0;
1669 u32 next0 = TCP_ESTABLISHED_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1676 n_left_to_next -= 1;
1678 b0 = vlib_get_buffer (vm, bi0);
1679 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1682 if (PREDICT_FALSE (tc0 == 0))
1684 error0 = TCP_ERROR_INVALID_CONNECTION;
1688 th0 = tcp_buffer_hdr (b0);
1689 /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
1690 * dangling reference. */
1691 is_fin = tcp_is_fin (th0);
1693 /* SYNs, FINs and data consume sequence numbers */
1694 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
1695 + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
1697 /* TODO header prediction fast path */
1699 /* 1-4: check SEQ, RST, SYN */
1700 if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0)))
1702 error0 = TCP_ERROR_SEGMENT_INVALID;
1703 TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0,
1704 vnet_buffer (b0)->tcp.seq_number,
1705 vnet_buffer (b0)->tcp.seq_end);
1709 /* 5: check the ACK field */
1710 if (tcp_rcv_ack (tc0, b0, th0, &next0, &error0))
1713 /* 6: check the URG bit TODO */
1715 /* 7: process the segment text */
1716 if (vnet_buffer (b0)->tcp.data_len)
1717 error0 = tcp_segment_rcv (tm, tc0, b0, &next0);
1719 /* 8: check the FIN bit */
1720 if (PREDICT_FALSE (is_fin))
1722 /* Enter CLOSE-WAIT and notify session. Don't send ACK, instead
1723 * wait for session to call close. To avoid lingering
1724 * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
1725 tc0->state = TCP_STATE_CLOSE_WAIT;
1726 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
1727 if (vnet_buffer (b0)->tcp.data_len == 0)
1730 next0 = TCP_ESTABLISHED_NEXT_DROP;
1732 stream_session_disconnect_notify (&tc0->connection);
1733 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
1737 b0->error = node->errors[error0];
1738 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1740 tcp_rx_trace_t *t0 =
1741 vlib_add_trace (vm, node, b0, sizeof (*t0));
1742 tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
1745 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1746 n_left_to_next, bi0, next0);
1749 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1752 errors = session_manager_flush_enqueue_events (my_thread_index);
1753 tcp_established_inc_counter (vm, is_ip4, TCP_ERROR_EVENT_FIFO_FULL, errors);
1754 tcp_flush_frame_to_output (vm, my_thread_index, is_ip4);
1756 return from_frame->n_vectors;
1760 tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1761 vlib_frame_t * from_frame)
1763 return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1767 tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
1768 vlib_frame_t * from_frame)
1770 return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1774 VLIB_REGISTER_NODE (tcp4_established_node) =
1776 .function = tcp4_established,
1777 .name = "tcp4-established",
1778 /* Takes a vector of packets. */
1779 .vector_size = sizeof (u32),
1780 .n_errors = TCP_N_ERROR,
1781 .error_strings = tcp_error_strings,
1782 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1785 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1786 foreach_tcp_state_next
1789 .format_trace = format_tcp_rx_trace_short,
1793 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
1796 VLIB_REGISTER_NODE (tcp6_established_node) =
1798 .function = tcp6_established,
1799 .name = "tcp6-established",
1800 /* Takes a vector of packets. */
1801 .vector_size = sizeof (u32),
1802 .n_errors = TCP_N_ERROR,
1803 .error_strings = tcp_error_strings,
1804 .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
1807 #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
1808 foreach_tcp_state_next
1811 .format_trace = format_tcp_rx_trace_short,
1816 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
1818 vlib_node_registration_t tcp4_syn_sent_node;
1819 vlib_node_registration_t tcp6_syn_sent_node;
1822 tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1823 vlib_frame_t * from_frame, int is_ip4)
1825 tcp_main_t *tm = vnet_get_tcp_main ();
1826 u32 n_left_from, next_index, *from, *to_next;
1827 u32 my_thread_index = vm->thread_index, errors = 0;
1829 from = vlib_frame_vector_args (from_frame);
1830 n_left_from = from_frame->n_vectors;
1832 next_index = node->cached_next_index;
1834 while (n_left_from > 0)
1838 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1840 while (n_left_from > 0 && n_left_to_next > 0)
1842 u32 bi0, ack0, seq0;
1845 tcp_header_t *tcp0 = 0;
1846 tcp_connection_t *tc0;
1847 tcp_connection_t *new_tc0;
1848 u32 next0 = TCP_SYN_SENT_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
1855 n_left_to_next -= 1;
1857 b0 = vlib_get_buffer (vm, bi0);
1859 tcp_half_open_connection_get (vnet_buffer (b0)->
1860 tcp.connection_index);
1862 ack0 = vnet_buffer (b0)->tcp.ack_number;
1863 seq0 = vnet_buffer (b0)->tcp.seq_number;
1864 tcp0 = tcp_buffer_hdr (b0);
1868 ip4_header_t *ip40 = vlib_buffer_get_current (b0);
1869 tcp0 = ip4_next_header (ip40);
1871 (tcp_connection_t *)
1872 stream_session_lookup_transport_wt4 (&ip40->dst_address,
1876 SESSION_TYPE_IP4_TCP,
1882 (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
1885 /* SYNs, FINs and data consume sequence numbers */
1886 vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
1887 + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
1890 * 1. check the ACK bit
1894 * If the ACK bit is set
1895 * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
1896 * the RST bit is set, if so drop the segment and return)
1897 * <SEQ=SEG.ACK><CTL=RST>
1898 * and discard the segment. Return.
1899 * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
1903 if (ack0 <= tc0->iss || ack0 > tc0->snd_nxt)
1905 if (!tcp_rst (tcp0))
1906 tcp_send_reset (tc0, b0, is_ip4);
1910 /* Make sure ACK is valid */
1911 if (tc0->snd_una > ack0)
1916 * 2. check the RST bit
1921 /* If ACK is acceptable, signal client that peer is not
1922 * willing to accept connection and drop connection*/
1924 tcp_connection_reset (tc0);
1929 * 3. check the security and precedence (skipped)
1933 * 4. check the SYN bit
1936 /* No SYN flag. Drop. */
1937 if (!tcp_syn (tcp0))
1941 if (tcp_options_parse (tcp0, &tc0->rcv_opts))
1944 /* Valid SYN or SYN-ACK. Move connection from half-open pool to
1945 * current thread pool. */
1946 pool_get (tm->connections[my_thread_index], new_tc0);
1947 clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
1948 new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
1949 new_tc0->c_thread_index = my_thread_index;
1950 new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
1951 new_tc0->irs = seq0;
1952 new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
1953 new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] =
1954 TCP_TIMER_HANDLE_INVALID;
1956 /* If this is not the owning thread, wait for syn retransmit to
1957 * expire and cleanup then */
1958 if (tcp_half_open_connection_cleanup (tc0))
1959 tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
1961 if (tcp_opts_tstamp (&new_tc0->rcv_opts))
1963 new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
1964 new_tc0->tsval_recent_age = tcp_time_now ();
1967 if (tcp_opts_wscale (&new_tc0->rcv_opts))
1968 new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
1970 new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
1971 << new_tc0->snd_wscale;
1972 new_tc0->snd_wl1 = seq0;
1973 new_tc0->snd_wl2 = ack0;
1975 tcp_connection_init_vars (new_tc0);
1977 /* SYN-ACK: See if we can switch to ESTABLISHED state */
1978 if (PREDICT_TRUE (tcp_ack (tcp0)))
1980 /* Our SYN is ACKed: we have iss < ack = snd_una */
1982 /* TODO Dequeue acknowledged segments if we support Fast Open */
1983 new_tc0->snd_una = ack0;
1984 new_tc0->state = TCP_STATE_ESTABLISHED;
1986 /* Make sure las is initialized for the wnd computation */
1987 new_tc0->rcv_las = new_tc0->rcv_nxt;
1989 /* Notify app that we have connection. If session layer can't
1990 * allocate session send reset */
1991 if (stream_session_connect_notify (&new_tc0->connection, 0))
1993 tcp_send_reset (new_tc0, b0, is_ip4);
1994 tcp_connection_cleanup (new_tc0);
1998 /* Make sure after data segment processing ACK is sent */
1999 new_tc0->flags |= TCP_CONN_SNDACK;
2001 /* Update rtt with the syn-ack sample */
2002 new_tc0->bytes_acked = 1;
2003 tcp_update_rtt (new_tc0, vnet_buffer (b0)->tcp.ack_number);
2004 TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
2006 /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
2009 new_tc0->state = TCP_STATE_SYN_RCVD;
2011 /* Notify app that we have connection */
2012 if (stream_session_connect_notify (&new_tc0->connection, 0))
2014 tcp_connection_cleanup (new_tc0);
2015 tcp_send_reset (tc0, b0, is_ip4);
2016 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
2021 tcp_make_synack (new_tc0, b0);
2022 next0 = tcp_next_output (is_ip4);
2027 /* Read data, if any */
2028 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
2031 error0 = tcp_segment_rcv (tm, new_tc0, b0, &next0);
2032 if (error0 == TCP_ERROR_PURE_ACK)
2033 error0 = TCP_ERROR_SYN_ACKS_RCVD;
2037 tcp_make_ack (new_tc0, b0);
2038 next0 = tcp_next_output (new_tc0->c_is_ip4);
2043 b0->error = error0 ? node->errors[error0] : 0;
2044 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2046 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2047 clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
2048 clib_memcpy (&t0->tcp_connection, tc0,
2049 sizeof (t0->tcp_connection));
2052 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2053 n_left_to_next, bi0, next0);
2056 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2059 errors = session_manager_flush_enqueue_events (my_thread_index);
2063 vlib_node_increment_counter (vm, tcp4_established_node.index,
2064 TCP_ERROR_EVENT_FIFO_FULL, errors);
2066 vlib_node_increment_counter (vm, tcp6_established_node.index,
2067 TCP_ERROR_EVENT_FIFO_FULL, errors);
2070 return from_frame->n_vectors;
2074 tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
2075 vlib_frame_t * from_frame)
2077 return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2081 tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
2082 vlib_frame_t * from_frame)
2084 return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2088 VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
2090 .function = tcp4_syn_sent,
2091 .name = "tcp4-syn-sent",
2092 /* Takes a vector of packets. */
2093 .vector_size = sizeof (u32),
2094 .n_errors = TCP_N_ERROR,
2095 .error_strings = tcp_error_strings,
2096 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2099 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2100 foreach_tcp_state_next
2103 .format_trace = format_tcp_rx_trace_short,
2107 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
2110 VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
2112 .function = tcp6_syn_sent_rcv,
2113 .name = "tcp6-syn-sent",
2114 /* Takes a vector of packets. */
2115 .vector_size = sizeof (u32),
2116 .n_errors = TCP_N_ERROR,
2117 .error_strings = tcp_error_strings,
2118 .n_next_nodes = TCP_SYN_SENT_N_NEXT,
2121 #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
2122 foreach_tcp_state_next
2125 .format_trace = format_tcp_rx_trace_short,
2129 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
2132 * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
2133 * as per RFC793 p. 64
2136 tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2137 vlib_frame_t * from_frame, int is_ip4)
2139 tcp_main_t *tm = vnet_get_tcp_main ();
2140 u32 n_left_from, next_index, *from, *to_next;
2141 u32 my_thread_index = vm->thread_index, errors = 0;
2143 from = vlib_frame_vector_args (from_frame);
2144 n_left_from = from_frame->n_vectors;
2146 next_index = node->cached_next_index;
2148 while (n_left_from > 0)
2152 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2154 while (n_left_from > 0 && n_left_to_next > 0)
2158 tcp_header_t *tcp0 = 0;
2159 tcp_connection_t *tc0;
2160 u32 next0 = TCP_RCV_PROCESS_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
2167 n_left_to_next -= 1;
2169 b0 = vlib_get_buffer (vm, bi0);
2170 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
2172 if (PREDICT_FALSE (tc0 == 0))
2174 error0 = TCP_ERROR_INVALID_CONNECTION;
2178 tcp0 = tcp_buffer_hdr (b0);
2180 /* SYNs, FINs and data consume sequence numbers */
2181 vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
2182 + tcp_is_syn (tcp0) + tcp_is_fin (tcp0)
2183 + vnet_buffer (b0)->tcp.data_len;
2186 * Special treatment for CLOSED
2190 case TCP_STATE_CLOSED:
2196 * For all other states (except LISTEN)
2199 /* 1-4: check SEQ, RST, SYN */
2201 (tcp_segment_validate (vm, tc0, b0, tcp0, &next0)))
2203 error0 = TCP_ERROR_SEGMENT_INVALID;
2207 /* 5: check the ACK field */
2210 case TCP_STATE_SYN_RCVD:
2212 * If the segment acknowledgment is not acceptable, form a
2214 * <SEQ=SEG.ACK><CTL=RST>
2217 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2219 tcp_send_reset (tc0, b0, is_ip4);
2223 /* Update rtt and rto */
2224 tc0->bytes_acked = 1;
2225 tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
2227 /* Switch state to ESTABLISHED */
2228 tc0->state = TCP_STATE_ESTABLISHED;
2230 /* Initialize session variables */
2231 tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
2232 tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
2233 << tc0->rcv_opts.wscale;
2234 tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2235 tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2236 stream_session_accept_notify (&tc0->connection);
2238 /* Reset SYN-ACK retransmit timer */
2239 tcp_retransmit_timer_reset (tc0);
2241 case TCP_STATE_ESTABLISHED:
2242 /* We can get packets in established state here because they
2243 * were enqueued before state change */
2244 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2248 case TCP_STATE_FIN_WAIT_1:
2249 /* In addition to the processing for the ESTABLISHED state, if
2250 * our FIN is now acknowledged then enter FIN-WAIT-2 and
2251 * continue processing in that state. */
2252 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2255 /* If FIN is ACKed */
2256 if (tc0->snd_una == tc0->snd_una_max)
2258 ASSERT (tcp_fin (tcp0));
2260 tc0->state = TCP_STATE_FIN_WAIT_2;
2261 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2263 /* Stop all timers, 2MSL will be set lower */
2264 tcp_connection_timers_reset (tc0);
2267 case TCP_STATE_FIN_WAIT_2:
2268 /* In addition to the processing for the ESTABLISHED state, if
2269 * the retransmission queue is empty, the user's CLOSE can be
2270 * acknowledged ("ok") but do not delete the TCB. */
2271 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2274 /* check if rtx queue is empty and ack CLOSE TODO */
2276 case TCP_STATE_CLOSE_WAIT:
2277 /* Do the same processing as for the ESTABLISHED state. */
2278 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2281 case TCP_STATE_CLOSING:
2282 /* In addition to the processing for the ESTABLISHED state, if
2283 * the ACK acknowledges our FIN then enter the TIME-WAIT state,
2284 * otherwise ignore the segment. */
2285 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2288 /* XXX test that send queue empty */
2289 tc0->state = TCP_STATE_TIME_WAIT;
2290 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2294 case TCP_STATE_LAST_ACK:
2295 /* The only thing that [should] arrive in this state is an
2296 * acknowledgment of our FIN. If our FIN is now acknowledged,
2297 * delete the TCB, enter the CLOSED state, and return. */
2299 if (!tcp_rcv_ack_is_acceptable (tc0, b0))
2302 /* Apparently our FIN was lost */
2305 /* Don't "make" fin since that increments snd_nxt */
2310 tc0->state = TCP_STATE_CLOSED;
2311 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2313 /* Don't delete the connection/session yet. Instead, wait a
2314 * reasonable amount of time until the pipes are cleared. In
2315 * particular, this makes sure that we won't have dead sessions
2316 * when processing events on the tx path */
2317 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
2319 /* Stop retransmit */
2320 tcp_retransmit_timer_reset (tc0);
2325 case TCP_STATE_TIME_WAIT:
2326 /* The only thing that can arrive in this state is a
2327 * retransmission of the remote FIN. Acknowledge it, and restart
2328 * the 2 MSL timeout. */
2330 if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
2333 tcp_make_ack (tc0, b0);
2334 tcp_timer_reset (tc0, TCP_TIMER_WAITCLOSE);
2335 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2344 /* 6: check the URG bit TODO */
2346 /* 7: process the segment text */
2349 case TCP_STATE_ESTABLISHED:
2350 case TCP_STATE_FIN_WAIT_1:
2351 case TCP_STATE_FIN_WAIT_2:
2352 if (vnet_buffer (b0)->tcp.data_len)
2353 error0 = tcp_segment_rcv (tm, tc0, b0, &next0);
2355 case TCP_STATE_CLOSE_WAIT:
2356 case TCP_STATE_CLOSING:
2357 case TCP_STATE_LAST_ACK:
2358 case TCP_STATE_TIME_WAIT:
2359 /* This should not occur, since a FIN has been received from the
2360 * remote side. Ignore the segment text. */
2364 /* 8: check the FIN bit */
2365 if (!tcp_fin (tcp0))
2370 case TCP_STATE_ESTABLISHED:
2371 case TCP_STATE_SYN_RCVD:
2372 /* Send FIN-ACK notify app and enter CLOSE-WAIT */
2373 tcp_connection_timers_reset (tc0);
2374 tcp_make_fin (tc0, b0);
2375 next0 = tcp_next_output (tc0->c_is_ip4);
2376 stream_session_disconnect_notify (&tc0->connection);
2377 tc0->state = TCP_STATE_CLOSE_WAIT;
2378 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2380 case TCP_STATE_CLOSE_WAIT:
2381 case TCP_STATE_CLOSING:
2382 case TCP_STATE_LAST_ACK:
2385 case TCP_STATE_FIN_WAIT_1:
2386 tc0->state = TCP_STATE_TIME_WAIT;
2387 tcp_connection_timers_reset (tc0);
2388 tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2389 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2391 case TCP_STATE_FIN_WAIT_2:
2392 /* Got FIN, send ACK! */
2393 tc0->state = TCP_STATE_TIME_WAIT;
2394 tcp_connection_timers_reset (tc0);
2395 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
2396 tcp_make_ack (tc0, b0);
2397 next0 = tcp_next_output (is_ip4);
2398 TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
2400 case TCP_STATE_TIME_WAIT:
2401 /* Remain in the TIME-WAIT state. Restart the 2 MSL time-wait
2404 tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
2407 TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
2410 b0->error = error0 ? node->errors[error0] : 0;
2412 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2414 tcp_rx_trace_t *t0 =
2415 vlib_add_trace (vm, node, b0, sizeof (*t0));
2416 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2419 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2420 n_left_to_next, bi0, next0);
2423 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2426 errors = session_manager_flush_enqueue_events (my_thread_index);
2430 vlib_node_increment_counter (vm, tcp4_established_node.index,
2431 TCP_ERROR_EVENT_FIFO_FULL, errors);
2433 vlib_node_increment_counter (vm, tcp6_established_node.index,
2434 TCP_ERROR_EVENT_FIFO_FULL, errors);
2437 return from_frame->n_vectors;
2441 tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2442 vlib_frame_t * from_frame)
2444 return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2448 tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
2449 vlib_frame_t * from_frame)
2451 return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2455 VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
2457 .function = tcp4_rcv_process,
2458 .name = "tcp4-rcv-process",
2459 /* Takes a vector of packets. */
2460 .vector_size = sizeof (u32),
2461 .n_errors = TCP_N_ERROR,
2462 .error_strings = tcp_error_strings,
2463 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2466 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2467 foreach_tcp_state_next
2470 .format_trace = format_tcp_rx_trace_short,
2474 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
2477 VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
2479 .function = tcp6_rcv_process,
2480 .name = "tcp6-rcv-process",
2481 /* Takes a vector of packets. */
2482 .vector_size = sizeof (u32),
2483 .n_errors = TCP_N_ERROR,
2484 .error_strings = tcp_error_strings,
2485 .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
2488 #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
2489 foreach_tcp_state_next
2492 .format_trace = format_tcp_rx_trace_short,
2496 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
2498 vlib_node_registration_t tcp4_listen_node;
2499 vlib_node_registration_t tcp6_listen_node;
2502 * LISTEN state processing as per RFC 793 p. 65
2505 tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2506 vlib_frame_t * from_frame, int is_ip4)
2508 u32 n_left_from, next_index, *from, *to_next;
2509 u32 my_thread_index = vm->thread_index;
2510 u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
2512 from = vlib_frame_vector_args (from_frame);
2513 n_left_from = from_frame->n_vectors;
2515 next_index = node->cached_next_index;
2517 while (n_left_from > 0)
2521 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2523 while (n_left_from > 0 && n_left_to_next > 0)
2528 tcp_header_t *th0 = 0;
2529 tcp_connection_t *lc0;
2532 tcp_connection_t *child0;
2533 u32 error0 = TCP_ERROR_SYNS_RCVD, next0 = TCP_LISTEN_NEXT_DROP;
2540 n_left_to_next -= 1;
2542 b0 = vlib_get_buffer (vm, bi0);
2543 lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
2547 ip40 = vlib_buffer_get_current (b0);
2548 th0 = ip4_next_header (ip40);
2552 ip60 = vlib_buffer_get_current (b0);
2553 th0 = ip6_next_header (ip60);
2556 /* Create child session. For syn-flood protection use filter */
2558 /* 1. first check for an RST: handled in dispatch */
2559 /* if (tcp_rst (th0))
2562 /* 2. second check for an ACK: handled in dispatch */
2563 /* if (tcp_ack (th0))
2565 tcp_send_reset (b0, is_ip4);
2569 /* 3. check for a SYN (did that already) */
2571 /* Create child session and send SYN-ACK */
2572 child0 = tcp_connection_new (my_thread_index);
2573 child0->c_lcl_port = lc0->c_lcl_port;
2574 child0->c_rmt_port = th0->src_port;
2575 child0->c_is_ip4 = is_ip4;
2576 child0->state = TCP_STATE_SYN_RCVD;
2580 child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
2581 child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
2585 clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
2586 sizeof (ip6_address_t));
2587 clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
2588 sizeof (ip6_address_t));
2591 if (stream_session_accept (&child0->connection, lc0->c_s_index, sst,
2594 error0 = TCP_ERROR_CREATE_SESSION_FAIL;
2598 if (tcp_options_parse (th0, &child0->rcv_opts))
2603 child0->irs = vnet_buffer (b0)->tcp.seq_number;
2604 child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
2605 child0->rcv_las = child0->rcv_nxt;
2607 /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
2608 * segments are used to initialize PAWS. */
2609 if (tcp_opts_tstamp (&child0->rcv_opts))
2611 child0->tsval_recent = child0->rcv_opts.tsval;
2612 child0->tsval_recent_age = tcp_time_now ();
2615 if (tcp_opts_wscale (&child0->rcv_opts))
2616 child0->snd_wscale = child0->rcv_opts.wscale;
2618 child0->snd_wnd = clib_net_to_host_u16 (th0->window)
2619 << child0->snd_wscale;
2620 child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
2621 child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
2623 tcp_connection_init_vars (child0);
2624 TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0);
2626 /* Reuse buffer to make syn-ack and send */
2627 tcp_make_synack (child0, b0);
2628 next0 = tcp_next_output (is_ip4);
2631 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2633 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2634 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2635 clib_memcpy (&t0->tcp_connection, lc0,
2636 sizeof (t0->tcp_connection));
2639 b0->error = node->errors[error0];
2641 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2642 n_left_to_next, bi0, next0);
2645 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2647 return from_frame->n_vectors;
2651 tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2652 vlib_frame_t * from_frame)
2654 return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2658 tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
2659 vlib_frame_t * from_frame)
2661 return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2665 VLIB_REGISTER_NODE (tcp4_listen_node) =
2667 .function = tcp4_listen,
2668 .name = "tcp4-listen",
2669 /* Takes a vector of packets. */
2670 .vector_size = sizeof (u32),
2671 .n_errors = TCP_N_ERROR,
2672 .error_strings = tcp_error_strings,
2673 .n_next_nodes = TCP_LISTEN_N_NEXT,
2676 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2677 foreach_tcp_state_next
2680 .format_trace = format_tcp_rx_trace_short,
2684 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
2687 VLIB_REGISTER_NODE (tcp6_listen_node) =
2689 .function = tcp6_listen,
2690 .name = "tcp6-listen",
2691 /* Takes a vector of packets. */
2692 .vector_size = sizeof (u32),
2693 .n_errors = TCP_N_ERROR,
2694 .error_strings = tcp_error_strings,
2695 .n_next_nodes = TCP_LISTEN_N_NEXT,
2698 #define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
2699 foreach_tcp_state_next
2702 .format_trace = format_tcp_rx_trace_short,
2706 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
2708 vlib_node_registration_t tcp4_input_node;
2709 vlib_node_registration_t tcp6_input_node;
2711 typedef enum _tcp_input_next
2713 TCP_INPUT_NEXT_DROP,
2714 TCP_INPUT_NEXT_LISTEN,
2715 TCP_INPUT_NEXT_RCV_PROCESS,
2716 TCP_INPUT_NEXT_SYN_SENT,
2717 TCP_INPUT_NEXT_ESTABLISHED,
2718 TCP_INPUT_NEXT_RESET,
2722 #define foreach_tcp4_input_next \
2723 _ (DROP, "error-drop") \
2724 _ (LISTEN, "tcp4-listen") \
2725 _ (RCV_PROCESS, "tcp4-rcv-process") \
2726 _ (SYN_SENT, "tcp4-syn-sent") \
2727 _ (ESTABLISHED, "tcp4-established") \
2728 _ (RESET, "tcp4-reset")
2730 #define foreach_tcp6_input_next \
2731 _ (DROP, "error-drop") \
2732 _ (LISTEN, "tcp6-listen") \
2733 _ (RCV_PROCESS, "tcp6-rcv-process") \
2734 _ (SYN_SENT, "tcp6-syn-sent") \
2735 _ (ESTABLISHED, "tcp6-established") \
2736 _ (RESET, "tcp6-reset")
2738 #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
2741 tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
2743 transport_connection_t *tmp;
2747 u8 is_valid = (tc->c_lcl_port == hdr->dst_port
2748 && (tc->state == TCP_STATE_LISTEN
2749 || tc->c_rmt_port == hdr->src_port));
2754 stream_session_half_open_lookup (&tc->c_lcl_ip, &tc->c_rmt_ip,
2755 tc->c_lcl_port, tc->c_rmt_port,
2756 tc->c_transport_proto)))
2758 if (tmp->lcl_port == hdr->dst_port
2759 && tmp->rmt_port == hdr->src_port)
2761 clib_warning ("half-open is valid!");
2769 tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2770 vlib_frame_t * from_frame, int is_ip4)
2772 u32 n_left_from, next_index, *from, *to_next;
2773 u32 my_thread_index = vm->thread_index;
2774 tcp_main_t *tm = vnet_get_tcp_main ();
2776 from = vlib_frame_vector_args (from_frame);
2777 n_left_from = from_frame->n_vectors;
2779 next_index = node->cached_next_index;
2781 while (n_left_from > 0)
2785 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2787 while (n_left_from > 0 && n_left_to_next > 0)
2789 int n_advance_bytes0, n_data_bytes0;
2792 tcp_header_t *tcp0 = 0;
2793 tcp_connection_t *tc0;
2796 u32 error0 = TCP_ERROR_NO_LISTENER, next0 = TCP_INPUT_NEXT_DROP;
2804 n_left_to_next -= 1;
2806 b0 = vlib_get_buffer (vm, bi0);
2807 vnet_buffer (b0)->tcp.flags = 0;
2809 /* Checksum computed by ipx_local no need to compute again */
2813 ip40 = vlib_buffer_get_current (b0);
2814 tcp0 = ip4_next_header (ip40);
2815 n_advance_bytes0 = (ip4_header_bytes (ip40)
2816 + tcp_header_bytes (tcp0));
2817 n_data_bytes0 = clib_net_to_host_u16 (ip40->length)
2821 (tcp_connection_t *)
2822 stream_session_lookup_transport_wt4 (&ip40->dst_address,
2826 SESSION_TYPE_IP4_TCP,
2828 ASSERT (tcp_lookup_is_valid (tc0, tcp0));
2832 ip60 = vlib_buffer_get_current (b0);
2833 tcp0 = ip6_next_header (ip60);
2834 n_advance_bytes0 = tcp_header_bytes (tcp0);
2835 n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length)
2837 n_advance_bytes0 += sizeof (ip60[0]);
2840 (tcp_connection_t *)
2841 stream_session_lookup_transport_wt6 (&ip60->dst_address,
2845 SESSION_TYPE_IP6_TCP,
2847 ASSERT (tcp_lookup_is_valid (tc0, tcp0));
2851 if (PREDICT_FALSE (n_advance_bytes0 < 0))
2853 error0 = TCP_ERROR_LENGTH;
2857 /* Session exists */
2858 if (PREDICT_TRUE (0 != tc0))
2860 /* Save connection index */
2861 vnet_buffer (b0)->tcp.connection_index = tc0->c_c_index;
2862 vnet_buffer (b0)->tcp.seq_number =
2863 clib_net_to_host_u32 (tcp0->seq_number);
2864 vnet_buffer (b0)->tcp.ack_number =
2865 clib_net_to_host_u32 (tcp0->ack_number);
2867 vnet_buffer (b0)->tcp.hdr_offset = (u8 *) tcp0
2868 - (u8 *) vlib_buffer_get_current (b0);
2869 vnet_buffer (b0)->tcp.data_offset = n_advance_bytes0;
2870 vnet_buffer (b0)->tcp.data_len = n_data_bytes0;
2872 flags0 = tcp0->flags & filter_flags;
2873 next0 = tm->dispatch_table[tc0->state][flags0].next;
2874 error0 = tm->dispatch_table[tc0->state][flags0].error;
2876 if (PREDICT_FALSE (error0 == TCP_ERROR_DISPATCH
2877 || next0 == TCP_INPUT_NEXT_RESET))
2879 /* Overload tcp flags to store state */
2880 tcp_state_t state0 = tc0->state;
2881 vnet_buffer (b0)->tcp.flags = tc0->state;
2883 if (error0 == TCP_ERROR_DISPATCH)
2884 clib_warning ("disp error state %U flags %U",
2885 format_tcp_state, state0, format_tcp_flags,
2892 next0 = TCP_INPUT_NEXT_RESET;
2893 error0 = TCP_ERROR_NO_LISTENER;
2897 b0->error = error0 ? node->errors[error0] : 0;
2899 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2901 tcp_rx_trace_t *t0 =
2902 vlib_add_trace (vm, node, b0, sizeof (*t0));
2903 tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
2905 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2906 n_left_to_next, bi0, next0);
2909 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2912 return from_frame->n_vectors;
2916 tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2917 vlib_frame_t * from_frame)
2919 return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2923 tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
2924 vlib_frame_t * from_frame)
2926 return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2930 VLIB_REGISTER_NODE (tcp4_input_node) =
2932 .function = tcp4_input,
2933 .name = "tcp4-input",
2934 /* Takes a vector of packets. */
2935 .vector_size = sizeof (u32),
2936 .n_errors = TCP_N_ERROR,
2937 .error_strings = tcp_error_strings,
2938 .n_next_nodes = TCP_INPUT_N_NEXT,
2941 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
2942 foreach_tcp4_input_next
2945 .format_buffer = format_tcp_header,
2946 .format_trace = format_tcp_rx_trace,
2950 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
2953 VLIB_REGISTER_NODE (tcp6_input_node) =
2955 .function = tcp6_input,
2956 .name = "tcp6-input",
2957 /* Takes a vector of packets. */
2958 .vector_size = sizeof (u32),
2959 .n_errors = TCP_N_ERROR,
2960 .error_strings = tcp_error_strings,
2961 .n_next_nodes = TCP_INPUT_N_NEXT,
2964 #define _(s,n) [TCP_INPUT_NEXT_##s] = n,
2965 foreach_tcp6_input_next
2968 .format_buffer = format_tcp_header,
2969 .format_trace = format_tcp_rx_trace,
2973 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
2976 tcp_dispatch_table_init (tcp_main_t * tm)
2979 for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
2980 for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
2982 tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
2983 tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
2986 #define _(t,f,n,e) \
2988 tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
2989 tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
2992 /* SYNs for new connections -> tcp-listen. */
2993 _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
2994 _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
2995 _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_NONE);
2996 _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
2998 /* ACK for for a SYN-ACK -> tcp-rcv-process. */
2999 _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3000 _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3001 _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3002 /* SYN-ACK for a SYN */
3003 _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3005 _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3006 _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
3007 _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
3009 /* ACK for for established connection -> tcp-established. */
3010 _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3011 /* FIN for for established connection -> tcp-established. */
3012 _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3013 _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3015 _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3016 _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3018 _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
3019 _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
3021 /* ACK or FIN-ACK to our FIN */
3022 _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3023 _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
3025 /* FIN in reply to our FIN from the other side */
3026 _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3027 _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3028 /* FIN confirming that the peer (app) has closed */
3029 _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3030 _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3031 _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3033 _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3034 _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3036 _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3037 _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3038 _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3040 _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3041 _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3042 _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
3044 _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
3045 _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_CONNECTION_CLOSED);
3046 _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
3047 _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
3048 TCP_ERROR_CONNECTION_CLOSED);
3053 tcp_input_init (vlib_main_t * vm)
3055 clib_error_t *error = 0;
3056 tcp_main_t *tm = vnet_get_tcp_main ();
3058 if ((error = vlib_call_init_function (vm, tcp_init)))
3061 /* Initialize dispatch table. */
3062 tcp_dispatch_table_init (tm);
3067 VLIB_INIT_FUNCTION (tcp_input_init);
3070 * fd.io coding-style-patch-verification: ON
3073 * eval: (c-set-style "gnu")